Events at Physics |
Events on Friday, April 3rd, 2026
- Academic Calendar
- Spring Recess
- Abstract: *Note: actual end time may vary.* CONTACT: admin@secfac.wisc.edu
- Preliminary Exam
- Design of Magnetic Shielding for a Wide Field of View Sounding Rocket Instrument
- Time: 1:30 pm - 3:30 pm
- Place: Sterling B343
- Speaker: Sophia Nowkak
- Abstract: Diffuse hot gas near 10^6 K emits almost entirely in X-rays below 400 eV, creating a dense forest of emission lines. In order to disentangle the various elements and ionization states we require detectors with an energy resolution better than 2 eV FWHM. We are developing a new sounding rocket payload equipped with an array of high-resolution sensors. To get enough counts for a useful spectrum during the ~250s flight, the detector array will need >2.5^2 cm collecting area and ~1 steradian field of view (FOV).
Transition-edge sensors (TES) and their superconducting quantum interference device (SQUID) readouts are extremely sensitive to magnetic fields, and need to be well-shielded from changes in the ambient magnetic field. Primary magnetic field sources during flight are stray fields from the adiabatic demagnetization refrigerator (ADR) and the Earth’s magnetic field. Other TES-based space missions, like Athena and Micro-X, only have to accommodate the f-number of the converging beam from their telescope mirror, which X-ray reflection physics limits to ~f/4. They can therefore utilize long narrow cones of nested mu-metal and niobium in front of their detectors to improve shielding effectiveness. With our 1 sr direct FOV, this would necessitate impractically large and long shields. Using COMSOL Multiphysics, we explore a design which features a Nb superconducting mesh closing the front of the shield close to the detectors and enabling a much more compact shield. - Host: Dan McCammon