Postdoctoral Position in Ultra-Sensitive Applied Radiation Detection

Detection Physics (DP) Group within PNNL’s National Security Directorate specializes in developing ultra-low-background techniques and instrumentation aimed at making some of the world’s most sensitive radiation detection measurements. DP is seeking recent Ph.D. graduates to work at the intersection of national security, environmental sciences, and nuclear/particle physics instrumentation and analysis.  We are interested in one or more highly motivated, capable individuals to work in a dynamic, multidisciplinary environment as part of the Ultra-Sensitive Nuclear Measurements Program.

The Ultra-Sensitive Nuclear Measurements Program (USNMP) guides the lifecycle of PNNL research and operations in:

• Ultra-pure materials for radiation detection
• Ultra-sensitive radiation detection systems enabled by these materials
• Analytical and computational techniques to further reduce backgrounds and provide quantitative reporting from ultra-sensitive measurements
• Applications uniquely enabled by these capabilities across National Security, Environmental Science, and Fundamental Physics
• Collection and sample chemistry methods uniquely enabled by these capabilities to address challenging environments

The Ultra-Sensitive Nuclear Measurements Program (USNMP) includes a broad base of supporting capabilities:

• Central capability is the team: staff Nationally and Internationally recognized for USNM science leadership, creativity, and operational excellence
• PNNL Shallow Underground Laboratory
• Cleanroom and clean laboratory spaces dedicated to ultra-low-background R&D and operations around materials, detectors, sampling, & measurements
• Materials assay capabilities providing world-leading sensitivity for radioactive contaminants (U, K, Th, Co, Cs, …)
• Dedicated clean machining and fabrication capabilities for working with ultra-pure materials

We are interested in one or more highly motivated, capable individuals to work in a dynamic, multidisciplinary environment making quantitative measurements in ultra-low background systems. The endeavors span from the production mechanisms in the environment to the quantitative measurements in the laboratory, and the development of all the systems that are required to perform these low-level measurements. The work will primarily focus on the production of naturally occurring noble gas radioisotopes, collection and separation of noble gas samples, and radiometric measurements. Tritium and Ar-39 age-dating are also a focus. The position will involve significant hands-on work with low-background radiation detectors (germanium detectors, gas proportional counters, and liquid scintillators), sample collections and preparation (e.g. noble gas processing from whole air, noble gas purification, processing of water samples for tritium measurements), and the fundamental development of radiation detectors and gas separations systems.

The post-doctoral researcher will also have the opportunity to participate in the DP Group’s other applied radiation detection programs. These programs may provide bench-scale, hands-on laboratory instrumentation development opportunities, including working in the PNNL shallow underground laboratory cleanroom.

Qualifications

Minimum Qualifications:

• Candidates must have received a PhD within the past five years (60 months) or within the next 8 months from an accredited college or university.

Preferred Qualifications:

Candidates must be highly motivated and possess the interpersonal skills necessary to work with others in a team environment.   They must also be capable of working independently, and able to contribute in a professional manner via written and verbal communication.   Successful candidates will have excellent laboratory and problem-solving skills and be able to adapt to evolving priorities.  They must demonstrate an aptitude for meticulous attention to detail and the discipline to closely follow established procedures to perform intricate and exacting tasks associated with the preparation and handling of high purity materials.

The ideal candidate will have hands-on experience with one or more of the following:

   •    Noble gas detectors (gas proportional counters and cryogenic noble liquid scintillators) and understand the challenges to low-background techniques associated with these technologies

   •    Gamma spectrometry systems for radionuclide detection, preferably high-purity germanium detectors

   •    Design and fabrication of radiation detectors and shielding systems

   •    Low-noise analog electronics and signal processing

   •    Building, operating and troubleshooting high vacuum and/or cryogenic systems

   •    Ultra-sensitive detectors including silicon CCD arrays

   •    Cleanroom protocols and working in low-background environments

   •    Gloveboxes

   •    Gas chemistry, and pressurized gas-handling systems

   •    C++ and the ROOT analysis framework

   •    Sample processing and measurement for stable isotope geochronology