NASA Postdoctoral Program Opportunities

• U.S. Citizens Accepted
• Lawful Permanent Residents Accepted
• Foreign nationals who are in the U.S. at the time of application and on a valid J1 visa Accepted;
  Foreign nationals, asylees or refugees in the U.S. at the time of application with a valid EAD card and pending I-485 or I-589 forms Accepted.
  Note: At this time, GSFC does not accept NPP applications from citizens of designated countries unless they are Legal Permanent Residents of the U.S. The Designated Countries List is available at https://www.nasa.gov/oiir/export-control

This work focuses on ultrasensitive detector design, fabrication, characterization, and integration into suitable optical systems. Current research includes the development of superconducting transition edge sensors and superconducting integrated circuits for microcalorimeters of high-resolution x-ray detection and sensitive bolometers for measurements of submillimeter and millimeter wavelengths. We are exploring techniques for arraying the detectors in large formats, including superconducting bumpbond arrays and novel micromachining and wafer bonding concepts. Circuits are constructed to examine the aspects of the implementation of cryogenic arrays, such as thermal stability, interpixel crosstalk, robustness, and uniformity. Single pixel optimization is also pursued, including novel noise suppression geometries, linearity studies, polarization sensitivity, and use of multiple sensors to enable position sensitivity and increased dynamic range within a single pixel. Our group is developing absorber structures for the x-ray and far-infrared focal plane arrays, characterizing their optical properties, and demonstrating their integrability into detector structures. We are designing and building microwave structures for coupling bolometers to antenna structures and cryogenic filter structures compatible with large format arrays of ultrasensitive detectors. For more mature technologies, our group collaborates with GSFC instrument scientists to deploy testbed instruments at ground-based observatories. We also explore new technologies including magnetic calorimeters and hot electron bolometers as possible detector elements for space-based astrophysics.