Graduate Student Seminar with Arman Hossen

Arman Hossen of Washington University in St. Louis will be presenting the seminar "Observing High Energy X-ray and Gamma-ray Photons with Transition-Edge Sensor Microcalorimeters"

Transition-edge sensor (TES) microcalorimeters are quite versatile in X-ray and ɣ-ray astronomy due to their high energy resolution, fast rates of time-stamping of individual photons, and ~2 to 3 times higher resolution than the solid-state detectors. TES arrays can achieve energy resolutions of 55 eV FWHM (Full Width Half Maximum) at 97 keV. We are testing and optimizing a 32-pixels SLEDGEHAMMER detector developed by the NIST. This SLEDGEHAMMER detector has 32 microwave resonators inductively coupled with 32 SQUIDs, and SQUIDs are coupled with 32 Mo-Au TESs. A few SLEDGEHAMMER arrays can be used in the focal plane of balloon as well as space-borne telescopes enabling astrophysical observations with unprecedented energy resolutions. I will talk about the basic physics behind TESs, energy resolution, what we are doing and what we will do along with the application in the balloon flight to examine the source of the 511 keV ɣ-ray emission from the galactic center.