Speaker
Description
The application of transition edge sensors (TESs) to exotic atom X-ray
spectroscopy requires challenging techniques of measurement and
analysis. We have developed them through the pionic and kaonic atom
X-ray measurements with a 240-pixel TES array at hadron beamlines.
One of the important analyses is to investigate the charged particle
impacts on the TES array. The energy deposits of charged particles on
the array, especially on its silicon substrate, can cause small
thermal cross-talk pulses in all TESs. The pileup of the thermal
cross-talk and normal X-ray pulses degrades the energy resolution due
to poor pulse-height estimation via optimal filtering.
Recently we have found the shorter record-length analysis for the
piled-up pulses can improve the energy resolution (e.g., more than 1
eV at 6.9 keV). Generally, the optimal filtering for longer
record-length pulses without pileup contamination results in better
energy resolution. However, for the piled-up pulses, the benefit from
cutting the pileup region is bigger than the degradation due to
shorter records.
Here we will show the analysis details and the detector performance of
the kaonic helium X-ray measurement at J-PARC (Ibaraki, Japan). We
will discuss the influence of charged particle impacts on the TES
array to the optimal filter, the pulse-height estimation, the
background events, and the energy calibration. These analysis
techniques and the characterization of TES response to charged
particle impacts must be useful for future experiments at accelerator
beamlines and space missions.
| Student (Ph.D., M.Sc. or B.Sc.) | N |
|---|---|
| Less than 5 years of experience since completion of Ph.D | N |
