Measurements of the radio sky at ~100 MHz and below have the potential to open a new observational window in the universe's history.  At the lowest frequencies (tens of MHz), future observations may allow us to one day probe the cosmic "dark ages," an epoch that is unexplored to date.  Measurements at these frequencies are extremely challenging because of radio-frequency interference and ionospheric effects.  The state of the art among ground-based measurements dates from the 1960s, when Grote Reber caught brief glimpses of the ~2 MHz sky at low resolution.  The Array of Long Baseline Antennas for Taking Radio Observations from the Seventy-ninth parallel (ALBATROS) is a new experiment that aims to map the low-frequency sky using an array of autonomous antenna stations.  These antenna stations will observe independently, over long baselines, and will be interferometrically combined offline.  One array is under construction at the McGill Arctic Research Station on Axel Heiberg Island, a location that is exceptionally radio-quiet and has reduced ionospheric interference relative to lower-latitude sites.

The student who takes on this project will develop the hardware and/or electronics that are needed for the autonomous antenna stations.  Possible areas of work include investigating new antenna designs, developing and testing calibration electronics, improving remote communications with the antenna stations via Starlink, RFI mitigation of the fuel cell system that provides power for year-long antenna operation, and field testing the antenna stations at Uapishka Station.  In addition to developing a broad spectrum of experimental skills, the student will also gain exposure to working within a multi-institution collaborative setting.

For more information contact: Cynthia Chiang (hsin dot chiang at mcgill dot ca).

Posted on 2024/01/12

This project will focus on the development of a flexible drone-based calibrator that will be used for characterizing radio astronomy instruments.  Many radio astronomy experiments employ stationary telescopes (dishes or antennas) that are sited in remote locations.  One of the most important aspects of radio telescope characterization is the measurement of the spatial response on the sky, or the "beam pattern."  Because stationary telescopes are unable to actively repoint and scan over celestial sources, the only way to obtain complete beam pattern information is to move a source relative to the telescope, scanning the full field of view.  One solution to this problem is to use a drone that carries a transmitting source and antenna.  By developing multiple transmitters and antennas, this calibration platform can service radio astronomy experiments operating over a wide range of frequencies.

The student who takes on this project will have the opportunity to work on a variety of tasks related to the development of drone-based calibrator.  Possible areas of work include refining the construction of the custom-built drone (e.g., testing new flight controllers and motors), designing new antennas/transmitters for low-frequency operation, developing software tools for analyzing drone flight data, and participating in drone test flight campaigns both locally and at field sites (e.g., Uapishka Station and DRAO).

For more information contact: Cynthia Chiang (hsin dot chiang at mcgill dot ca).

Posted on 2024/01/12

Many of the observed nearby massive protoplanetary disks feature concentric rings of dust emission. The shape of these rings, combined with the simple equation of motion of dust grains in gaseous media, can be used to determine some of the fundamental parameters that control the micro and the macrophysics of early planet formation, including the dust-gas coupling parameter and the strength of turbulence, that are otherwise near impossible to determine without degeneracy either observationally or theoretically.

The student will first perform a literature search to develop a list of protoplanetary disks with sharp dust rings. They will then model the dust-gas interaction in protoplanetary disks to analyze the rings and quantify trends of the derived physical parameters with respect to system age, disk size, stellar luminosity, and stellar type. The project will strengthen the student's background in fluid dynamics, analytic and computational modelling in astrophysics using Python. In addition, the student will be trained in scientific communication through participation in regular group meetings.

For more information contact: Eve Lee (evelee at physics dot mcgill dot ca).

Posted on 2024/01/24

Planetary systems with an outer giant planet are observed to also preferentially harbour short-period super-Earths. This inner-outer planet correlation is pronounced around metal-rich stars and furthermore, the super-Earths around metal-rich stars are shown to be on tight orbits. The goal of this project is to determine whether the metallicity-period behaviour is shaped by the dynamical shuttling from one or two outer giants.>/p>

The student will perform N-body integrations using REBOUND evolving planetary systems of short-period super-Earths neighboured by outer giants of varying multiplicity and orbital properties, drawn from the observed eccentricity distributions of cold Jupiters. The project will strengthen the student's skills in numerical computation in astrophysics and the physics of orbital dynamics. In addition, the student will be trained in scientific communication through participation in regular group meetings.

Applicants with C programming knowledge preferred.

For more information contact: Eve Lee (evelee at physics dot mcgill dot ca).

Posted on 2024/01/24

Ariel is a European mission dedicated to atmospheric characterization of exoplanets set to launch in 2029. Its biggest advantage is in building a uniform statistical sample of atmospheric measurements. In preparation for its launch, the project aims to build a target list for addressing specific science questions, including the expected trends and scatter in chemical abundances as a function of orbital period, stellar type, and stellar metallicity from various formation scenarios.

The student will first familiarize themselves with the physics of planet formation that gives rise to the expected trends and scatter. They will then study the technical capabilities of Ariel from the published definition study report and build a Python-based code to 1) determine the required signal-to-noise to distinguish the expected trends and measure the scatter; and to 2) develop a list of known exoplanet targets for which Ariel can attain the required signal-to-noise. The project will provide an opportunity for the student to be a part of mission design while also building their data analysis skill. In addition, the student will be trained in scientific communication through participation in regular group meetings and through collaboration with exoplanet observers at McGill.

For more information contact: Eve Lee (evelee at physics dot mcgill dot ca).

Posted on 2024/01/24

Recent years have seen the development at McGill of an exciting class of models coined phase field crystal (PFC) models that couple interface kinetics to atomic-scale elasto-plasticity and topological defects in non-equilibrium phase transformations. These in include rapid solidification of liquid metals following rapid laser melting, a process at the heart of modern 3D metal printing.  The Intern will work with a PhD student in the Computational Materials Science Group to explore the phase space of a recently published PFC model. The focus will be to elucidate how strains emerging at rapidly fluctuating interfaces spawn defects and voids that migrate into and create metastable crystalline phases.

For more information contact: Nikolas Provatas (provatas at physics dot mcgill dot ca).

Posted on 2024/01/24

Fast Radio Bursts are a new and mysterious astrophysical phenomenon in which short (few ms) radio bursts appear randomly in the sky. FRBs are thought to be extragalactic due to their dispersion measures that are far higher than the maximum amount available in our Milky Way. With FRB event rates of ~1000 /sky/day, they raise an interesting puzzle regarding their origin, which lie at cosmological distances. Radio pulsars are rapidly rotating, highly magnetized neutron stars. As compact objects, they embody physical extremes of gravity, density and magnetic field. Thanks to their amazing clock-like properties, radio pulsars can be used as cosmic laboratories for a variety of experiments ranging from tests of relativistic gravity to studies of the interstellar medium.

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a new radio telescope recently built in Penticton, BC. CHIME's great sensitivity and large field-of-view (250 sq deg) enable the detection of many FRBs per day — in contrast to the fewer than 2 dozen discovered since 2007. CHIME is also an excellent pulsar observatory, able to detect hundreds of pulsars every day and enabling novel experiments using these high cadence observations.

Here are proposed several possible research projects involving data from CHIME. Possibilities include improving FRB characterization, studying repeating FRBs, localizing FRBs, monitoring radio pulsars, and developing software tools to search for pulsars with CHIME.

The student, who should have experience and familiarity with programming in the Linux environment, will be given astrophysical data sets from CHIME to first familiarize themselves with source properties. Then, depending on exact interest, will analyze existing data obtained in order to understand FRBs or the radio pulsar population, or help develop and test new algorithms for our new pulsar searching pipeline.

For more information contact: Victoria Kaspi (vkaspi at physics dot mcgill dot ca).

Posted on 2024/01/25

Experimental particles physics relies on always more precise detectors to investigate interactions produced at particle accelerators such as the Large Hadron Collider (LHC) at CERN or any future project like an Electron-Positron Collider. Calorimeters are sensitive to most charged and neutral particles and are one of the main components of a modern experiment. High particle multiplicity events becoming the new norm, detectors require unprecedented high granularity over very large volumes, with cells down to the cubic centimeter range. The international CALICE collaboration, in which McGill actively participates, is the largest R&D endeavor for these new concepts and developments.

The research project consists in analyzing the data taken by two CALICE prototypes of high granularity hadronic detectors, first the Digital version (DHCAL) and then the Analogue one (AHCAL). Investigating the response to beams of positrons, pions and muons should be done using novel methods based on connectivity, inertial tensor, energy density distributions, volume surfaces and other topological properties. The goal is to understanding their different applications and optimize both the particle identification and the energy response. Several basic analysis tools are already available, but code specific to the project should be developed.

This project will provide leading edge insights into the new techniques and their actual applications in current and future detectors. It will also bring familiarity with the manipulation of large data sets, and expose the student to international research with other CALICE members.

Strong motivation and commitment are expected. The candidate should be familiar with C programming and preferably already computer fluent under Linux. The work should take place at McGill under almost daily supervision. Basic understanding of particle physics concepts would be an asset.

For more information contact: François Corriveau (corriveau at physics dot mcgill dot ca).

Posted on 2024/01/26

The summer researcher will join the McGill Exoplanet Characterization Alliance and will work with Professor Cowan and Dr. Krishnamurthy on the analysis of high resolution spectroscopic observations of the iconic TRAPPIST-1 planetary system. The student will master an existing pipeline to reduce the data and search for the signature of molecules in the atmospheres of multiple TRAPPIST planets. In the case that no molecules are detected, the student will run numerical injection-recovery experiments to quantify their results. The presence or absence of molecules will be compared to the theoretical predictions and previous observations in the literature.

The student will join weekly group meetings and 1-on-1 meetings with Professor Cowan. They will make weekly progress reports and post their next research objectives on the group Slack. The student will learn about scientific programming, atmospheric science, and exoplanet observations. They will develop their scientific writing and visualization skills to present results succinctly and elegantly. They will learn how to solve problems independently, how to ask more experienced researchers for help, and how to adapt strategies when facing seemingly intractable problems. Prior programming experience in Python is a requirement. Astronomy coursework and research experience are a plus.

For more information contact: Nicolas Cowan (cowan at physics dot mcgill dot ca).

Posted on 2024/01/26

The summer researcher will join the McGill Exoplanet Characterization Alliance and will work with Professor Cowan on the design of the Ariel mission, a space telescope launching in 2029 to complete a survey of exoplanet atmospheres.  The student will develop and use Python software tools to simulate Ariel observations of exoplanets. This will entail predicting the signal and noise for thousands of known exoplanets and planetary candidates, making parameter cuts to narrow down the sample of potential targets, parameterizing possible exoplanet trends, and calculating observational time required to detect these trends.

The student will join weekly group meetings and 1-on-1 meetings with Professor Cowan. They will make weekly progress reports and post their next research objectives on the group Slack. The student will learn about scientific programming, atmospheric science, and exoplanet observations. They will develop their scientific writing and visualization skills to present results succinctly and elegantly. They will learn how to solve problems independently, how to ask more experienced researchers for help, and how to adapt strategies when facing seemingly intractable problems. Prior programming experience in Python is a requirement. Astronomy coursework and research experience are a plus.

For more information contact: Nicolas Cowan (cowan at physics dot mcgill dot ca).

Posted on 2024/01/26

Measuring glacier melt in the high Arctic provides critically important information on climate change.  This project focuses on the development of low-cost glacier melt monitoring instrumentation, consisting of poles that are embedded in the ice and that are outfitted with electronics to measure and record the resonant frequency.  The resonance depends sensitively upon the length of the pole that is exposed above the ice, thus providing a measure of changes in the height of the glacier surface. Constructing low-cost monitors will enable long-term glacier monitoring over large areas and with high spatial resolution.

The student who takes on this project will build a prototype of this monitoring system, with a focus on developing the electronics and logging, and will conduct prototype testing and validation. The work may also include developing plans for ruggedization and mass production, as well as field testing at local sites.  The work will be performed in a collaborative and interdisciplinary environment, with opportunities to interact with researchers from other institutions.

For more information contact: Cynthia Chiang (hsin dot chiang at mcgill dot ca).

Posted on 2024/01/27

New gauge symmetries are ubiquitous in extensions to the Standard Model of particle physics, which brings along the possibility of new particles charged under those symmetries. Generically, those particles can interact very weakly with particles in the Standard Model through oscillation or mixing between a new U(1) gauge boson and the Standard Model photon. Therefore, one can make these particles in the early universe, potentially providing a mechanism for generating the observed abundance of dark matter for specific values of the dark effective charge.In this project, the student will compute the irreducible abundance of these particles in the charge-mass plane, not requiring that they account for the majority of dark matter. This will involve modifying a python code which takes into account in-medium behaviour of particles in the primordial plasma of an expanding universe. Time permitting, the student will also determine the sensitivity of dark matter experiments to detecting this irreducible abundance. The student should ideally have have a background in statistical mechanics, electrodynamics, and two semesters of quantum.

For more information contact: Katelin Schutz (katelin dot schutz at mcgill dot ca).

Posted on 2024/01/29

The study of quantum effects in 2D materials have garnered significant attention in recent years due to their potential applications in the semiconductor industry as well as their potential for new applications. The goal of this project is to investigate the transport properties of thin bismuth at low temperature and at micro/nano scale, via measurements conducted on gated devices, i.e. analogue to a conventional  three-terminal device. It is to be expected that there could be quantum confinement  effects that link thin bismuth to the physics of  higher-order topological insulators, and these will be investigated in a variety of devices with different shape and thicknesses.

The student who takes on this project will take part both in the fabrications, characterization and electronic measurements of the devices as well as the analysis and interpretation of the data. The student  will be trained on atomic force microscopy and other characterization tools in the clean room, as well as to measure current and voltage on gated bismuth devices. Simultaneously,  the student will study topics in quantum mechanics, statistical mechanics, solid-state physics, topology, group theory, and relevant advanced topics.

For more information contact: Guillaume Gervais (gervais at physics dot mcgill dot ca).

Posted on 2024/01/29

The EXO (Enriched Xenon Observatory) collaboration is searching for lepton-number violating neutrino-less double beta decays (0νββ) in Xe-136. A positive observation would require the neutrino to be its own anti-particle, i.e. the neutrino has to be a Majorana particle, and shed light on various open questions in neutrino physics. The EXO collaboration is pursuing the development of the next-generation experiment called nEXO. This advanced detector requires the development of new technologies as well as detailed knowledge of the underlying physical processes to reach a sensitivity goal to the 0νββ half-life of 10²⁸ years.

We have been developing the Light-only Liquid Xenon (LoLX) experiment at our lab at McGill which aims to measure the emission of Cherenkov light in liquid xenon (LXe), investigate crosstalk between silicon photomultiplier devices, and deepen our understanding of light emission in LXe. These measurements will help constrain our simulation models for nEXO. LoLX may also improve event identification and suppress backgrounds by separating events where one or two electrons are emitted. This summer, we plan to perform several measurements with SiPMs installed in our upgraded LoLX cryostat. In addition, we plan to characterize the performance of these devices under intense UV light irradiation.

Your main task will be to simulate the expected response function of SiPMs in LoLX using the ray-tracing package CHROMA (GPU-based). You will also support the operation of the cryostat, participate in data taking campaigns and compare simulation results to recorded data. You will be embedded within the local neutrino group at McGill and learn about particle physics, the use of liquid xenon as a radiation detector, and how to read cryogenic temperatures using thermocouples and RTDs

This project is aimed at undergraduate students at all levels. All you need is an interest in nuclear/particle physics and a strong willingness to learn. Programming knowledge in any language (C or Python preferred) would be beneficial but is not necessary, as we have local experts who will be happy to teach you. You will apply your knowledge of thermodynamics in a real life experiment, and take part in the operation of the upgraded LoLX cryostat.

For more information contact: Thomas Brunner (thomas dot brunner at mcgill dot ca).

Posted on 2024/01/30

The EXO (Enriched Xenon Observatory) collaboration is searching for lepton-number violating neutrino-less double beta decays (0νββ) in Xe-136. A positive observation would require the neutrino to be its own anti-particle, i.e. the neutrino has to be a Majorana particle, and shed light on various open questions in neutrino physics. The EXO collaboration is pursuing the development of the next-generation experiment called nEXO. This advanced detector requires the development of new technologies as well as detailed knowledge of the underlying physical processes to reach a sensitivity goal to the 0νββ half-life of 10²⁸ years.

nEXO pans to use on the order of 40,000 SiPM photosensors inside its inner detector. The group at McGill is developing a setup to validate the performance of these devices during the construction phase of nEXO. You will implement the setup in the ray-tracing software CHROMA to study potential backgrounds from reflected light. In addition, you will support the characterization of SiPM sensors in the current setup to benchmark against your simulation results.

This project is aimed at undergraduate students at all levels. All you need is an interest in nuclear/particle physics and a strong willingness to learn. Programming knowledge in any language (C or Python preferred) would be beneficial but is not necessary, as we have local experts who will be happy to teach you. You will improve your programming skills, develop the geometry of the setup in simulations, and compare your results with data.

For more information contact: Thomas Brunner (thomas dot brunner at mcgill dot ca).

Posted on 2024/01/30

The nEXO (next Enriched Xenon Observatory) collaboration is searching for lepton-number violating neutrino-less double beta decays (0νββ) in Xe-136. A positive observation would require the neutrino to be its own anti-particle, i.e. the neutrino has to be a Majorana particle, and shed light on various open questions in neutrino physics. nEXO requires the development of advanced technologies as well as detailed knowledge of the underlying physical processes to reach a sensitivity goal of 10²⁸ years. To push the detector sensitivity even further, new technologies are required. One of those is the so-called Ba-tagging technique. Here, the Xe-decay daughter Ba-136 is located inside the detector volume after the decay, extracted from the volume and identified. This Ba-tagging technique will allow the unambiguous identification of ββ decays by clearly distinguishing them from background events. This technique will be particularly important to verify an observation once a positive 0νββ signal has been observed.

Paul traps are devices that are powerful tools used to store and manipulate ions. We plan to use this Nobel-Prize winning invention for our Ba-tagging development to store and cool ions after their extraction from Xe gas. In this project, you will develop electronics, supported by the department’s electronics engineer and a graduate student, to trap dust particles in a linear Paul trap. By shining laser light on this dust cloud it can be made visible. This development is intended to demonstrate the fascinating topic of ion storage to the broader audience during outreach and open-house events.

This project is aimed at undergraduate students at all levels. All you need is an interest in nuclear/particle physics and a strong willingness to learn. Some experience and interest in the design of radio-frequency electronics is an advantage. This project will consist of designing, building, and commissioning the electronics of a Paul trap. The successful applicant will do some preliminary research to establish parts, materials, techniques, and approaches, and will then use design software to formalize those into specifications, drawings, and plans. The construction will be done with a combination of 3-D printing and machine-shop work (if necessary). The goal will be a working, easy-to-use table-top-sized ion trap, suitable for classroom and outreach demonstrations.

For more information contact: Thomas Brunner (thomas dot brunner at mcgill dot ca).

Posted on 2024/01/30

Galaxy clusters are the largest gravitationally bound objects in the universe and are home to hundreds to thousands of individual galaxies. At the center of most galaxy clusters lies a single massive and unique galaxy, called the Brightest Cluster Galaxy or BCG.  BCGs grow with cosmic time as they accrete less massive systems and, possibly, gas from within the cluster itself. Understanding this process requires the discovery of distant cluster/BCG systems that are observed when the universe was much younger than it is today.

We are undertaking a spectroscopic campaign with several telescopes to measure the redshift of, and thus infer an accurate distance to, a representative sample of BCGs which lie in clusters with large distance estimates. The most recent data set of 7 galaxies was taken with the GNIRS instrument on the Gemini North observatory.

The student will first learn the basics of astrophysical spectroscopy and the specifics of the Gemini telescope.  They will then lead the reduction and analysis of the Gemini spectroscopic data using prewritten open-source software as well as develop custom routines in Python.  Some limited programming experience with Python is required, but the student will further develop their coding skills throughout the project. The primary goal is to measure the spectroscopic redshifts of the 7 galaxies, to confirm their distances and suitability for the larger study.

For more information contact: Tracy Webb (webb at physics dot mcgill dot ca).

Posted on 2024/02/01

Galaxy clusters are home to thousands of individual galaxies, held together by the gravity of huge dark matter halos and hot gas. In addition to providing tight cosmological constraints clusters are also excellent laboratories for the study of the evolution of galaxies, and the role of the dense environment in particular.  Some knowledge, however, of the bulk properties of a cluster sample, such as its mass distribution is required. Moreover, a comparison of these bulk properties, estimated in different ways, can provide insight into galaxy cluster growth and the conversion of the hot ambient cluster gas into galaxies.

In this project, the student will undertake a measurement of the mass of galaxy clusters based on their optical/near-infrared galaxy properties. This will first require that the student get up to speed on the methodology of measuring galaxy masses, through a literature review.  The student will then undertake a comparative study of this measurement and other means of mass estimation such as X-ray luminosity or velocity dispersion (the motion of the galaxies).  This will require the student to create custom Python routines that will operate on pre-existing cluster imaging and galaxy catalogues.  Some limited programming experience with Python is required, but the student will further develop their coding skills throughout the project.

For more information contact: Tracy Webb (webb at physics dot mcgill dot ca).

Posted on 2024/02/01

Particle physics aims to understand, among others, the structure and composition of matter. The Standard Model tries to unify all observables under a single theory of particles and their interactions. This is done experimentally for example at the Large Hadron Collider (LHC) of the research center CERN in Geneva by colliding protons at very high energies and looking at the products of the reactions.

The proposed project would be to analyze so-called Minimum Bias data from the ATLAS experiment. There are indications that a 3850 MeV state, made of 4 quarks, may exist instead of the usual 2- or 3-quark particles. Neutral strange particles will be used in this measurement, ensuring good signals and acceptable backgrounds.

The project would call for familiarization with standard analysis packages, large data manipulation, software development for event selection and detailed estimations of the backgrounds, as well as creation of new statistical tools to optimize the signals. It will also introduce the student to the field of particle physics and the challenges of working in large international collaborations.

Part of the work will be based on previous expertise in the research group. Knowledge of C++ and basic understanding of particle physics concepts would be assets. The student should be based at McGill and work within the ATLAS experimental group, under close and almost daily supervision, with opportunities to interact with the rest of the group and present progresses and results.

For more information contact: François Corriveau (corriveau at physics dot mcgill dot ca).

Posted on 2024/02/01

The first generation of stars (so-called PopIII stars) are believed to have formed inside metal-poor galaxies (sometimes called molecular cooling galaxies or MCGs) hosted by mini haloes where gas is cooled by molecular line transitions. The formation and evolution of mini haloes is still not fully understood. Radio telescope observations of the 21cm signal from high redshifts has the potential to unveil this mystery as the signal is affected by the presence of mini haloes. Low-frequency radio interferometers like the Hydrogen Epoch of Reionization Array (HERA) or the Square Kilometre Array (SKA) are currently being constructed with the goal of measuring this signal from very high redshifts. The 21-cm power spectrum, which is the Fourier transform of the two-point correlation function of the 21-cm fluctuations, contains a distinct signature of these mini haloes. Similarly, such signatures are also expected for the 21-cm bispectrum, which is the Fourier transform of the three-point correlation function of the same fields. Additionally, the bispectrum gives information about the underlying non-Gaussianity of the field, which the power spectrum cannot capture. In this project, we will perform theoretical calculations to forecast the bispectrum signal that future telescope data might be able to measure.

For this work, the plan is to use the semi-numerical code 21cmFAST. The student will first go through the code and run it. In parallel, the student will survey the literature to learn about the 21-cm signal and the minihaloes. The student will learn about the calculation of the bispectrum and the significance of this statistic. Finally, the student will produce results for the 21-cm bispectrum with the 21-cm fields generated by the 21cmFAST code including minihaloes.

The student will be a full member of our research group led by Dr. Adrian Liu and will therefore experience the full cycle of scientific research. They will attend weekly group meetings, 1-on-1 meetings, and weekly hack sessions with other group members. They will be able to participate in the Trottier Space Institute Summer Program, where there will be weekly workshops on professional development and research skills.

For more information contact: Adrian Liu (acliu at physics dot mcgill dot ca).

Posted on 2024/02/01

Fast radio bursts (FRBs) are short, bright bursts of electromagnetic radiation, the source of which remains unknown. Despite uncertainties about their progenitors, FRBs can be used as cosmological tools. The same way turning on a flashlight in a dusty room allows one to see all the particles that were secretly floating around in the air, FRBs are our cosmic flashlights. Encoded in their signal is information about the number density of electron along the path of the photons. As such, FRBs can be used for studying mass cosmological ionization events as well as the baryon density of the universe.

This project will involve developing new techniques for studying cosmology using fast radio bursts.

The student will be trained in both the simulation and analysis of cosmological data. Mock FRB datasets as well as complementary cosmological observation (such as the cosmic microwave background) will be simulated using existing software, although it is expected that the student will extend this software to include new ways of probing cosmology with FRBs.

The student will be a full member of our research group led by Dr. Adrian Liu and will therefore experience the full cycle of scientific research. They will attend weekly group meetings, 1-on-1 meetings, and weekly hack sessions with other group members. They will be able to participate in the Trottier Space Institute Summer Program, where there will be weekly workshops on professional development and research skills.

For more information contact: Adrian Liu (acliu at physics dot mcgill dot ca).

Posted on 2024/02/01

How do multiple interacting polymers behave in confined environments?  This is a fundamental problem in confined polymer physics with important implications in a range of biological systems, from chromosomal segregation and plasmid distribution in dividing bacteria to chromatin organization.  The Reisner group is developing nanofluidic assays to explore how multiple polymer molecules behave in confined environments.  These in vitro confinement models, where all parameters can be directly controlled, will enable testing of whether simple polymer theories can explain DNA organization in biological systems.  In detail, nanofluidics will be used to confine multiple chains, using either pneumatic actuated lids to trap molecules in nanocavity structures, or electrophoretic traps based on AC electrokinetics.  Differential staining of the chains will be used to independently assess the conformation of each chain, determine the degree of partitioning/mixing and assess coupled diffusion of the chain center-of-mass positions.  Measurements will be performed as a function of cavity dimension, salt concentration, polymer topology, chain number and size.

The student will learn how to perform confined polymer experiments on Reisner lab fluorescence microscopy platforms.  This training includes chain staining protocols, nanofluidic device and microscope operation.  The student will then  develop automated analysis routines in either Matlab or python to extract key qualities from the videomicroscopy data.  The student will be supervised in the lab by a PhD student and meet with Prof. Reisner on a weekly basis.

For more information contact: Walter Reisner (reisner at physics dot mcgill dot ca).

Posted on 2024/02/05

We are looking for motivated undergraduates to assist in creating quantum optics tools and techniques useful for our research in (1) generating quantum states of light and motion and sensing near (and beyond?) the Standard Quantum Limit, (2) developing a superfluid ultralight dark matter detector, and / or (3) developing a water-based dosimeter for cancer radiotherapy. Depending on interests there may also be projects studying new ways to control the motion of solid objects with the forces exerted by laser light.

For more information contact: Jack Sankey (Childress) (jack dot sankey at mcgill dot ca).

Posted on 2024/02/05

The Hydrogen Epoch of Reionization Array (HERA) is a massively redundant radio interferometer designed to study the universe during Cosmic Dawn and the Epoch of Reionization, when the first stars and galaxies in the universe lit up the cosmos and ionized the intergalactic medium. HERA aims to better understand this period of cosmic history through observations of the cosmologically redshifted 21-cm line associated with the hyperfine hydrogen transition; however, this signal is incredibly faint and may only be teased out of the noise after a great deal of averaging. In order to enable this averaging, the raw data must first be calibrated to remove the effects of the various electronics that the signal encounters as it propagates through the signal chain. Correlation Calibration, or CorrCal, is a novel calibration technique that simultaneously leverages the strengths and mitigates the shortcomings of commonly employed calibration techniques.

In this project, we will use CorrCal to calibrate HERA data and compare our results against those obtained using the currently employed HERA calibration pipeline. Calibrating large interferometric data sets is a rich and complex challenge, so the student should be prepared to learn a great deal of new material. The project will require working with the HERA software stack, building on the CorrCal package, and using HERA??s supercomputing resources, so some familiarity with Linux and a strong familiarity with Python are required.

The student will learn the relevant fundamentals of radio interferometry and calibration, and will have opportunities to learn about 21-cm cosmology. They will further develop their scientific programming skills and gain experience working with, and possibly developing, version controlled software in a collaborative setting. They will also develop skills pertaining to visualizing data and communicating research results.

For more information contact: Jon Sievers (sievers at physics dot mcgill dot ca).

Posted on 2024/02/05

ALBATROS is an array of independent radio telescopes that will, for the first time, map the sky below 10 MHz at high resolution. We will save the signals from each telescope and combine them offline, which will require us to synchronize the different telescopes with nanosecond-level precision. We have preliminary data from test telescopes at Uapishka Station on the east side of Lake Manicouagan, and at the McGill Arctic Research Station.

The project entails enhancing the existing test suite of the ALBATROS correlation pipeline. The student will be responsible for creating code to generate simulated data packets, and test pipeline features using their simulated data. Features include functionality that manages missing packets and handle the integer wraparound during long integrations. Additionally, the student will develop tests for the two-antenna cross-correlation and quantization corrections, both vital components of the ALBATROS pipeline. The final goal of this project is to integrate their code into the main ALBATROS pipeline.

For more information contact: Jon Sievers (sievers at physics dot mcgill dot ca).

Posted on 2024/02/05

Fast radio bursts (FRBs) are some of the most mysterious objects in astronomy. Telescopes like CHIME and (soon) CHORD can find thousands of FRBs, but to really make progress requires localizing the FRB locations with sub-arcsecond precision. CHIME and CHORD are building outrigger telescopes to help with this, but one of the major uncertainties is from position-dependent delays induced by Earth's ionosphere.

Global navigational satellite systems (GNSS) constellations like GPS broadcast navigation data at multiple frequencies, which lets one measure ionospheric delays. In this project, the student will process archival GNSS data from above radio observatories to reconstruct GNSS positions and ionospheric models, and compare to public models for the ionosphere. The key deliverable will be (likely python) code that can predict the ionospheric delay above a telescope in arbitrary directions on the sky, and estimate the uncertainty in the delay. We can then use these models to correct FRB positions, hopefully allowing us to unlock from owhere within their host galaxies they arise.

For more information contact: Jon Sievers (sievers at physics dot mcgill dot ca).

Posted on 2024/02/05

In the current computer architecture, the memory and logic units are implemented in separate devices and connected via a system bus which led to a “von Neumann bottleneck” regarding the data transfer rate and power dissipation. In the big data era, it is becoming increasingly desirable to resolve this bottleneck. To this end, various in-memory computing architectures have emerged where logic and memory are in a single device. Among them, the ferroelectric semiconductor field effect transistor (FeSFET) is an attractive device where the memory is implemented in the bistable ferroelectricity and the logic is implemented in the FET. A problem to solve for realizing practical FeSFET is to find a ferroelectric semiconductor that has large and stable ferroelectricity, fast electric polarization switching speed, proper electronic band gap (< 2 eV), and compatible with industrial fabrication processes.

In this project, we shall search proper ferroelectric semiconductors for FeSFET from a different angle by applying materials informatics. Note that humans have discovered in nature or synthesized by hand over a hundred million materials (solids, molecules, sequences). However, if one asks what properties of the materials were measured, the number becomes shockingly small. For example, we know elastic constants, dielectric constants, heat conductivity for a few hundred compounds, and ferroelectricity for ~1000 compounds etc. This situation presents a good technological opportunity: in the vast space of existing materials, it is likely that proper ferroelectric semiconductors exist for FeSFET applications. Obviously, one cannot experimentally measure - even theoretically calculate, large number of materials to search by brute-force.

Therefore, we shall build a statistical learning model for classifying ferroelectric semiconductors and deploy this model to large experimental material databases (i.e. ICSD etc) to screen possible FeSFET channel materials. The research includes the following tasks:

• Build a set of physics motivated descriptors for ferroelectric semiconductors.
• Verify the descriptors using known compounds of ferroelectric materials
• Build a tree-based classifier for large electric polarization and small bandgap.
• Deploy the classifier to screen material candidates from databases ICSD and Materials-Project.
• Time permitting, carry out density functional theory (DFT) calculations for several material candidates to theoretically verify the informatics search.

For more information contact: Hong Guo (guo at physics dot mcgill dot ca).

Posted on 2024/02/07

VERITAS is a VHE (Very High Energy: E > 100 GeV) instrument composed of an array of four 12-m telescopes situated in Arizona, designed to detect and study VHE gamma-rays from astrophysical sources using the atmospheric Cherenkov technique. The instrument is mature (on-sky since 2007) and the collaboration has published more than 100 results; we continue to acquire data with a focus on the transient sky. The original analysis software is custom-built, but the VHE field is moving towards standard, open-source, python-based packages such as gammapy (see gammapy.org). In this project the student will work with gammapy to pursue new VERITAS data analysis, specifically of gamma-ray binaries, developing new tools for gammapy as required.

For more information contact: Ken Ragan (regan at physics dot mcgill dot ca).

Posted on 2024/02/08

In the current computer architecture, the memory and logic units are implemented in separate devices and connected via a system bus which led to a ``von Neumann bottleneck'' regarding the data transfer rate and power dissipation. In the big data era, it is becoming increasingly desirable to resolve this bottleneck. To this end, the ferroelectric semiconductor field effect transistor (FeSFET) is a very attractive device for ??in-memory?? computing where the memory is implemented in the bistable ferroelectricity while the logic is implemented in the FET. The emerging group III nitride Al_1-xSc_xN is a known ferroelectric semiconductor. However, to use this compound as the channel material of FeSFET, steps need to be taken to reduce its large band gap of ~5 eV to improve carrier transport properties of in-memory logic applications. By atomic first principles calculations, we recently found that alloying a very small amount of Sb impurities into Al_1-xSc_xN reduces the band gap to ~1.76 eV while maintaining ferroelectricity of the quaternary compound Al_1-xSc_xSb_yN_1-y.

In this project, we shall predict the device characteristics of FeSFETs made of Al_1-xSc_xSb_yN_1-y as the channel material for a few concentrations x, y. We shall calculate carrier transport (logic operation) from atomic first principles based on Keldysh nonequilibrium Green??s function (NEGF) formalism and density functional theory (DFT), as implemented in our NEGF-DFT software Nanodcal. We shall also investigate the dynamic switching (memory operation) of the electric polarization by developing a code that solves the Landau-Khalatnikov dynamic equations where the needed Landau parameters were already obtained in our recent work. Combined, we wish to reach an understanding of the FeSFET in-memory device with Al_1-xSc_xSb_yN_1-y as the channel material.

The research includes the following steps:

• Build a transistor model for FeSFET with Al_1-xSc_xSb_yN_1-y as the channel material, using our device builder DS.
• Carry out NEGF-DFT calculations of the FeSFET and determine the carrier transport properties versus bias and gate potentials, using our NEGF-DFT software Nanodcal.
• Develop a code to solve the Landau-Khalatnikov equations to evaluate switching dynamics of the electric polarization in the FeSFET.
• Using the results, evaluate merits and challenges of III-nitride compound Al_1-xSc_xSb_yN_1-y as channel materials of FeSFET.

For more information contact: Hong Guo (guo at physics dot mcgill dot ca).

Posted on 2024/02/08

CdZnTe (CZT) semiconductors are the subject of extensive investigations as the material of choice for radiation detectors used in health care and security applications. This is due to the potential of CZT to deliver clear signals for its stronger interaction with radiation, and its efficient generation and collection of charge carriers. These attributes, related to CZT higher average atomic number and its relatively large bandgap, address several detrimental limitations in the current X-ray detection technology. However, exploiting the CZT potential still faces major challenges as it requires high purity, low-defect, and homogenous semi-insulating crystals. These prerequisites are yet to be satisfied in commercial detector-grade CZT crystals, which typically suffer high concentrations of defects including Te-rich inclusions, dislocations, and twin- and subgrain-boundaries. These imperfections limit the charge collection and increase the detector noise.

In this research, we shall theoretically investigate some atomic-level properties of CZT to predict useful material properties. The research includes the following steps.

• Build a grain boundary (GB) model using known atomistic methods such as the GBstedio¹, generate several common twin-boundaries of CZT crystals.
• Relax the GB structures using the AI driven university potential model as implemented in our density functional theory (DFT) package RESCU+. Verify the resulting GB by DFT.
• Calculate electronic structures of the CZT GB.
• Time permitting, calculate carrier transport properties across the CZT GB by our quantum transport package Nanodcal which implements the Keldysh nonequilibrium Green??s function (NEGF) formalism with DFT.
• Interacting with our experimental collaborators and industrial partners of the CZT project.

¹ H. Ogawa. GBstudio: A Builder Software on Periodic Models of CSL Boundaries for Molecular Simulation. Materials Transactions, 47(11):2706-2710, 2006.

A topological superconductor in one dimension can be described as a chain of Majorana fermions. In fact, any fermion can be described as two coupled Majoranas. In a topological superconductor, however, the two Majoranas on the chain edges decouple from the rest of the system. These edge Majorana fermions are extremely robust to local perturbation and are considered a promising building block of qubits. In this project we will explore a driven topological superconductor (or equivalently a spin chain) in the presence of transverse and longitudinal disorder. The system will be characterized through the topological part of its entanglement entropy (TEE).

For more information contact: Tami Pereg-Barnea (tamipb at physics dot mcgill dot ca).

Posted on 2024/02/12

Recently it has been realised that magnetized white dwarfs are cold enough that they are in the process of crystallizing. Just as in the Earth's core, the growth of the solid leads to ejection of light elements which drives convection creating a dynamo. This kind of crystallization-driven dynamo could explain the magnetic fields seen in white dwarfs. However, the dynamo region is thought to be located deep inside the white dwarf core. This project will be to calculate how the magnetic field profile changes over time due to ohmic diffusion, and in particular how long it take for the dynamo-generated field in the core to diffuse to the surface. The calculation will involve solving the ohmic diffusion equation numerically on a grid in radius, putting in accurate values for the electrical conductivity as a function of radius. The results will be compared with measured ages of magnetic white dwarfs to see if they explain the observations.

For more information contact: Andrew Cumming (cumming at physics dot mcgill dot ca).

Posted on 2024/02/12

At the extreme pressures inside neutron stars, nuclei can take on non-spherical shapes, forming a phase of matter known as nuclear pasta. Understanding the properties of nuclear pasta is important for interpreting observations of neutron stars such as neutron star mergers and supernovae. This project will use a class of phase field model to explore the potential for forming different solid phases under high pressure conditions, such as those that exist in the interior of neutron stars. The project will start by constructing, analytically, a pressure-structure phase diagram predicted by the model. Following this, dynamical simulations will be performed to explore the kinetics of non-equilibrium phase formation within the stellar interior.

For more information contact: Nikolas Provatas (provatas at physics dot mcgill dot ca) and Andrew Cumming (cumming at physics dot mcgill dot ca).

Posted on 2024/02/12

Leveraging frequency modes in ring resonators to forge a synthetic dimension [1,2] unfolds new horizons in the realm of high-dimensional quantum photonic simulators and quantum information processing via frequency encoding. Despite the promising avenue, the current scope of synthetic frequency space in photonics is confined to linear systems, posing a limitation on its utility for simulating a broader range of Hamiltonians.

This project aims to design an integrated photonic ring resonator based on Kerr nonlinear material to facilitate the realization of a synthetic frequency dimension mediated by nonlinear frequency conversions. More specifically, this will be based on four-wave-mixing Bragg scattering mediated by third-order optical nonlinearity [3].

The student working on this project will numerically simulate and design integrated waveguides made of silicon or silicon nitride for the phase matching of the relevant nonlinear processes and achieve a design that is suitable for microfabrication. If time permits, the student will have the opportunity to build an experimental setup for testing fabricated integrated photonic circuits.

[1] L. Yuan, Q. Lin, M. Xiao, and S. Fan, “Synthetic dimension in photonics,” Optica 5, 1396 (2018).
[2] T. Ozawa, H. M. Price, “Topological quantum matter in synthetic dimensions.” Nat Rev Phys 1, 349 (2019).
[3] B. A. Bell, K. Wang, A. S. Solntsev, D. N. Neshev, A. A. Sukhorukov, and B. J. Eggleton, “Spectral photonic lattices with complex long-range coupling,” Optica 4, 1433 (2017).

For more information contact: Kai Wang (k dot wang at mcgill dot ca).

Posted on 2024/02/13

In quantum technologies, single-photon emitters are pivotal, serving as the backbone for many applications. The second-order correlation function, denoted as g(2), is instrumental in discerning the photon statistics of a light source, acting as a critical indicator of a single-photon emitter's quality. Although the measurement of g(2) is a well-established procedure within the field of optics, the adaptation of this measurement to cater to specific emitter samples—particularly, enabling the spatial resolution of the g(2) function—remains an important task that we aim to address.

The student involved in this project will construct a Hanbury–Brown–Twiss (HBT) setup. This setup will facilitate the characterization of the second-order correlation for solid-state single-photon emitters at near-infrared wavelengths. Additionally, should time allow, the student will investigate the feasibility of employing single-photon-sensitive cameras, such as the Single Photon Avalanche Diode (SPAD) sensor, to achieve spatially resolved g(2) measurements.

For more information contact: Kai Wang (k dot wang at mcgill dot ca).

Posted on 2024/02/13

Nanostructured optical metasurfaces offer a compact and scalable solution for manipulating the quantum states of light across various degrees of freedom. Despite their potential, the scope of linear transformations achievable by a single-layer metasurface is notably constrained. To overcome this limitation, recent advancements have leveraged multiplane light conversion techniques, employing a phase surface—such as a spatial light modulator—alongside a mirror. This approach facilitates multiple reflections of a light beam across different regions of the phase surface, significantly broadening the range of possible linear transformations. The exploration of metasurface designs capable of intricate transformations of quantum light states stands as a frontier of research interest.

The student working on this project will develop a metasurface tailored for integration within a multiplane light conversion apparatus, aiming to achieve a wide range of transformations on optical beams characterized by their polarization and Hermite-Gaussian modal basis. Should time allow, the student will also have the opportunity to practically simulate the designed metasurface using spatial light modulators and to assemble a multiplane light conversion setup in the lab.

For more information contact: Kai Wang (k dot wang at mcgill dot ca).

Posted on 2024/02/13

Recently, we have demonstrated electron emission from metal nanotips driven by a single cycle, phase locked THz pulse. This emission produces millions of keV energy electrons in a single femtosecond burst which we seek to leverage for a single-shot electron microscope based on point-projection microscopy. Currently we are trying to better understand the dynamics of the emission mechanism from the metal tip under such extreme fields exceeding 50 GV/m. To do this, we will introduce a second time-delayed pulse of THz light while measuring the energy spectrum of the emitted and streaked electrons.

The student will participate in these experiments being led by several graduate students, assisting in the experiment through the design and fabrication of a waveguide structure to locally enhance the field at the tip. They will perform simple finite element COMSOL simulations to better understand the field interaction at the tip, assist in the experiment and the data analysis through computational models of electron dynamics.

For more information contact: David Cooke (david dot cooke at mcgill dot ca).

Posted on 2024/02/13

New windows on the cosmos that can revolutionize our understanding of fundamental physics are ushered in with new technology. We are developing fast digital and analog electronics to enable quantum superconducting sensors and ultra-large radio receiver arrays.

This project will involve the testing and characterization of new instrumentation for radio and mm-wave cosmology and fast radio transient telescopes.

The student will engage in both software development for instrumentation and lab measurements. Detailed documentation and reporting will be required.

The student will join the Cosmology Instrumentation Laboratory and participate in the full cycle of scientific research, attending group meetings, team work sessions, and 1-on-1 meetings with other group members. They will be able to participate in the Trottier Space Institute Summer Program, where there will be weekly workshops on professional development and research skills.

For more information contact: Matt Dobbs (matt dot dobbs at mcgill dot ca).

Posted on 2024/02/15

In this project, the goal is to study topological materials in two dimensions. In 1D there is the well-known Su–Schrieffer–Heeger (SSH) model, which is one of the simplest examples of a topologically non-trivial system. In 2D, there are many variants of this model, as well as experimental systems, including those connected to quantum Hall materials and graphene-like materials. Some of the interesting properties, include topological protection to quantum information and robustness to disorder, which we will explore in these materials. The project can have both, an experimental and theoretical component depending on the student’s interest.

For more information contact: Michael Hilke (hilke at physics dot mcgill dot ca).

Posted on 2024/02/17

The nature of matter in the universe as well as interacions between elementary particles hold many fundamental mysteries. The study of high energy proton-proton collisions produced in a controlled laboratory environment is an ideal approach to attemp to shed light on these mysteries.

The ATLAS detector, located at the CERN laboratory in Switzerland, is designed to record the results of the highest energy proton-proton collisions in the world. The detector is undergoing major upgrades in order to be ready to record the results of proton-proton collisions at the future High-Luminosity Large Hadron Collider (LHC), scheduled to begin operation in 2029. One of these upgrades consists in replacing the entire electronic readout of the Liquid Argon Calorimeter detector, a sub-system responsible for precisely measuring the energy of electrons/photons produced in proton-proton collisions.

The overarching goal of the summer project is to develop and benchmark different types of digital filters that are optimized for the real-time reconstruction of energy deposited in the ATLAS liquid argon calorimeter system, and to study their performance. Specifically, (1) the student will learn how to use existing software tools for simulating the electronic response of the future calorimetner readout system. (2) The student will explore different possible machine learning models guided by the feasibility and ease of their implementation in hardware description language on the future customed digital signal processing system currently being designed. Considerations include, e.g. the number of parameters and type of mathematical operations required by each model. (3) The performance of the most promising machine learning model(s) will be studied under different experimental conditions.

The student will carry-out leading-edge research and develop computer programming skills, learn about the construction of different Machine Learning models and their optimization, learn about general concepts of particle detector instrumentation, different concepts related to analogue and digital electronics, and develop some knowledge of Field-Programmable Gate Arrays (FPGAs). Through the international context of their research work, the student will be exposed to an international network of scientists, providing them with a unique opportunity to develop their communication and collaborative skills.

Research activities will take place in person at McGill University. The student will perform this work in collaboration with a supervisor. The student's progress will be monitored through weekly meetings. Additionally, the student will regularly interact with other members of the McGill ATLAS research group (research associates, engineer and graduate student), as well as collaborate with colleagues at other institutes in Canada and internationally.

The student is required to be resourceful, curious and have a strong desire to learn. Knowledge and experience with computers (unix-based OS, shell scripts, python, C++, git) is considered an asset.

For more information contact: Brigitte Vachon (brigittes dot vachon at mcgill dot ca).

Posted on 2024/02/20

The nature of matter in the universe as well as interacions between elementary particles hold many fundamental mysteries. The study of high energy proton-proton collisions produced in a controlled laboratory environment is an ideal approach to attemp to shed light on these mysteries.

The ATLAS detector, located at the CERN laboratory in Switzerland, is designed to record the results of the highest energy proton-proton collisions in the world. The detector is undergoing major upgrades in order to be ready to record the results of proton-proton collisions at the future High-Luminosity Large Hadron Collider (LHC), scheduled to begin operation in 2029. One of these upgrades consists in replacing the entire electronic readout of the Liquid Argon Calorimeter detector, a sub-system responsible for precisely measuring the energy of electrons/photons produced in proton-proton collisions. As part of the new electronic readout, the off-detector signal processor system will be responsible for processing, in real-time, the incoming digitized data stream of 345 Tbps from the calorimeter. This off-detector system will consist in ~ 400 monolithic custom-designed blades hosting two high-performance Field-Programmable Gate Arrays (FPGA) processing units.

The goal of the summer project is to contribute to the design and construction of a test infrastructure at McGill for the quality assessment of these complex, customed digital electronics cards. The student will (1) help install, commission and operate differents parts of the test infrastructure (2) help develop operational and monitoring scripts, software and databases for the interpretation of the various electronics tests being considered, and (3) write and test simple test firmware.

The student will carry-out leading-edge research and acquire knowledge in the general areas of detector instrumentation, state-of-the-art electronics, computer programming, develop problem solving skills, acquire hands-on laboratory experience, and develop knowledge and experience with the use of FPGAs. Through the international context of their research work, the student will be exposed to an international network of scientists, providing them with a unique opportunity to develop communication and collaborative skills.

Research activities will take place in person at McGill University. The student will perform this work in collaboration with a supervisor. The student's progress will be monitored through weekly meetings. Additionally, the student will regularly interact with other members of the McGill ATLAS research group (research associates, engineer and graduate student), as well as collaborate with colleagues at other institutes in Canada and internationally.

The student is required to be resourceful, curious and have a strong desire to learn. Knowledge and experience with computers (unix-based OS, shell scripts, python, C++, git) is considered an asset.

[Note: For IPP Summer Student Fellowship recipients, this project is particularly well-suited because it will allow you to pursue this project during your stay at CERN under the supervision of McGill group members working at the CERN-based electronic test infrastructure currently being developed.]

For more information contact: Brigitte Vachon (brigittes dot vachon at mcgill dot ca).

Posted on 2024/02/20

The nature of matter in the universe as well as interacions between elementary particles hold many fundamental mysteries. The study of high energy proton-proton collisions produced in a controlled laboratory environment is an ideal approach to attemp to shed light on these mysteries.

The student will participate in the development of an analysis framework for the interpretation of measurements performed using proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider (LHC).

Specifically, the student will help develop the statistical methods and an analysis framework for the combination and interpretation of measurements of extremelly rare physics reactions in terms of constraints on possible new physics phenomena. The student tasks will include learning about different statistical methods, as well as the writing and validation of analysis code written in C++/Python, and based on ROOT analysis libraries.

The student will carry-out leading-edge research and acquire knowledge in the general areas of data analysis and statistical interpretation of data, computer programming, develop problem solving skills, develop familiarity with general concepts and tools in experimental particle physics. Through the international context of their research work, the student will be exposed to an international network of scientists, providing them with a unique opportunity to develop communication and collaborative skills.

Research activities will take place in person at McGill University. The student will perform this work in collaboration with a supervisor. The student's progress will be monitored through weekly meetings. Additionally, the student will regularly interact with other members of the McGill ATLAS research group, as well as collaborate with colleagues at other institutes in Canada and internationally.

The student is required to be resourceful, curious and have a strong desire to learn. Knowledge and experience with computers (unix-based OS, shell scripts, python, C++, git) is considered an asset. Familiarity with complex statistical methods, or demonstrated ability to independently learn complex theoretical concepts, is also considered an asset.

For more information contact: Brigitte Vachon (brigittes dot vachon at mcgill dot ca).

Posted on 2024/02/20

Iron is ubiquitous in rocks and minerals. During the extraction of critical metals from minerals by chemical dissolution (hydrometallurgical processes), iron is both a problematic contaminant that needs to be removed prior to processing and also a useful marker that can provide information on the progress of the extraction process. The iron may occur in two basic forms: As (i) distinct iron-rich minerals such as magnetite or (ii) chemically substituted in the same mineral component as the metal being sought. Knowing the mineralogical speciation of the iron helps in the optimization of the initial steps used to remove the primary iron-rich gangue (low-value) minerals by physical processes before moving on to chemical processing. In addition, if it can be demonstrated that the substitutional iron is bound in crystallographic sites which are chemically resistant to extraction, then the hydrometallurgical conditions used for the recovery of the critical metals (e.g., acid strength, process temperature, leaching times,…) can be fine-tuned in order to recover rare metals selectively. On the other hand, if the iron is hosted by readily leached crystallographic sites, it can be removed selectively prior to the recovery of the critical metals.

⁵⁷Fe Mössbauer spectroscopy can be used to investigate the magnetic and chemical environments of iron in ore samples. It can be used to identify and quantify the iron-containing minerals. It can also be used to provide information on the valence and coordination environments of the iron where it occurs in substitutional sites. As it is a transmission measurement, it is sensitive to all of the iron present in a sample so that it can be used to detect and quantify chemically bound iron that is resistant to chemical extraction. Over the course of this project you will measure a variety of ore samples that have been subject to a range of processing conditions and your results will be used to guide the optimization of the sequencing and conditions to be used to recover the critical metals from the starting ores.

For more information contact: Dominic Ryan (dominic at physics dot mcgill dot ca).

Posted on 2024/02/29