Argonne National Laboratory invites applications for a Postdoctoral Appointee to advance the deployment, commissioning, and scientific use of Transition-Edge Sensor (TES) X-ray microcalorimeter spectrometers at the Advanced Photon Source. The successful candidate will work at the interface of cutting-edge cryogenic detector technology and synchrotron science, helping to integrate TES spectrometers into APS beamlines and enabling transformative experiments in X-ray spectroscopy.
This is an opportunity to contribute to a growing capability at one of the world’s premier synchrotron facilities, collaborate with detector scientists and beamline teams, and lead forefront experiments that leverage the sub-eV to few-eV energy resolution and high quantum efficiency of TES arrays.
Key Responsibilities
Deploy, commission, and operate TES X-ray microcalorimeter spectrometers at APS beamlines, including cryostat integration, beamline interfaces, alignment, and stability optimization.
Perform pathfinding scientific experiments at APS beamlines, which will define the baseline for the usage of the TES X-ray microcalorimeter spectrometers.
Collaborate with detector, electronics, and beamline staff to integrate readout and controls (e.g., SQUID-based time- or microwave-multiplexed systems) with beamline data acquisition and control (EPICS/Bluesky).
Develop and maintain data acquisition, calibration, and analysis pipelines, including pulse processing (e.g., optimal filtering), pileup mitigation, drift correction, and energy-scale stability.
Design, propose, and execute high-impact in-house spectroscopy experiments (e.g., XES, XANES/EXAFS, resonant/non-resonant scattering).
Diagnose and mitigate performance limiters (e.g., vibration, magnetic fields, microphonics, thermal loading, stray light), and contribute to detector/system modeling and optimization for count rate, resolution, and throughput.
Document methods and develop user-facing procedures and best practices for reliable operation during user runs; contribute to open-source software and instrument documentation as appropriate.
Publish scientific and technical results in peer-reviewed journals and present at conferences; engage with the broader cryogenic-detector and synchrotron communities.
Maintain a strong commitment to safety, quality, and inclusive teamwork in a dynamic user facility environment.
What We Offer
The opportunity to help build and lead a high-impact TES spectroscopy capability at a world-class user facility.
Mentorship and collaboration with experts in cryogenic detectors, X-ray science, and beamline operations.
Access to state-of-the-art facilities and resources at the APS and across Argonne.
Competitive compensation and benefits; professional development and conference travel support.
Initial appointment for two years, with the possibility of extension to a third year contingent on performance and funding.
Work Environment
On-site position at Argonne National Laboratory’s campus in Lemont, IL.
Work will include on-shift support during user operations, occasional off-hours activities during commissioning, and some travel for collaborations and conferences.
Application Instructions Please apply via Argonne’s Careers site and include:
Cover letter describing your background, interests, and fit for the position.
Curriculum vitae, including a list of publications.
Contact information for three professional references.
Application review will begin immediately and continue until the position is filled. For full consideration, submit your application as soon as possible.
About the Advanced Photon Source
The Advanced Photon Source at Argonne National Laboratory is a U.S. Department of Energy Office of Science User Facility providing ultra-bright, high-energy X-ray beams to a global community of researchers. APS enables discoveries across materials science, chemistry, geoscience, energy technologies, and biology.
Position Requirements
This level of knowledge is typically achieved through a formal education in physics, applied physics, electrical engineering, materials science, or a related field at the PhD level with zero to five years of employment experience.
Hands-on experience in one or more of the following:
Cryogenic detectors (TES, MKID, or related) and SQUID-based readout.
Low-temperature cryogenics (e.g., ADRs, dilution refrigerators, pulse-tube cryocoolers) and high-/ultra-high-vacuum systems.
X-ray spectroscopy or synchrotron instrumentation and experiments.
Proficiency in scientific programming and data analysis (Python preferred; experience with NumPy/SciPy, Jupyter, version control). Experience with C/C++ or MATLAB is a plus.
Demonstrated ability to design and execute experiments, analyze complex datasets, and communicate results effectively through publications and presentations.
Strong teamwork, communication, and organizational skills, with the ability to work collaboratively in a multidisciplinary, user-focused environment.
Ability to model Argonne’s core values of impact, safety, respect, integrity, and teamwork.
Interpersonal skills, oral and written communication skills, and ability to interact with people at all levels both within and outside the laboratory.
Preferred Knowledge, Skills, and Experience
Experience with TES X-ray microcalorimeters, including pulse processing, energy calibration, and detector response modeling (electrothermal feedback, noise, crosstalk).
Experience with microwave SQUID multiplexing and associated cryogenic/RF electronics (e.g., cryo-LNAs, mixers, VNAs, spectrum analyzers), FPGA-based readout, or systems such as ROACH, RFSoC, etc..
Familiarity with EPICS, Bluesky, and beamline controls, timing, and triggering; development of IOCs, OPI screens, and integration with DAQ workflows.
Experience working at synchrotron or FEL facilities.
Knowledge of mechanical design for cryogenic/vacuum interfaces, magnetic shielding, vibration isolation, and thermal budgeting.
Background in X-ray spectroscopies (e.g. XES, HERFD, XANES/EXAFS) and associated analysis tools.
Experience with detector packaging, wirebonding, and/or cleanroom processes.
Job Family
Postdoctoral
Job Profile
Postdoctoral Appointee
Worker Type
Long-Term (Fixed Term)
Time Type
Full timeThe expected hiring range for this position is $70,758.00-$117,925.00.
Please note that the pay range information is a general guideline only. The pay offered to a selected candidate will be determined based on factors such as, but not limited to, the scope and responsibilities of the position, the qualifications of the selected candidate, business considerations, internal equity, and external market pay for comparable jobs. Additionally, comprehensive benefits are part of the total rewards package.
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