Predicting the response of a submillimeter bolometer to cosmic rays.
Bolometers designed to detect submillimeter radiation also respond to cosmic, gamma, and x rays. Because detectors cannot be fully shielded from such energy sources, it is necessary to understand the effect of a photon or cosmic-ray particle being absorbed. The resulting signal (known as a glitch) can then be removed from raw data. We present measurements using an Americium-241 gamma radiation source to irradiate a prototype bolometer for the High Frequency Instrument in the Planck Surveyor satellite. Our measurements showed no variation in response depending on where the radiation was absorbed, demonstrating that the bolometer absorber and thermistor thermalize quickly. The bolometer has previously been fully characterized both electrically and optically. We find that using optically measured time constants underestimates the time taken for the detector to recover from a radiation absorption event. However, a full thermal model for the bolometer, with parameters taken from electrical and optical measurements, provides accurate time constants. Slight deviations from the model were seen at high energies; these can be accounted for by use of an extended model.
Woodcraft
Adam L
AL
Department of Physics and Astronomy, University of Wales, Cardiff, P.O. Box 913, Cardiff CF24 3YB, United Kingdom. adam.woodcraft@physics.org
Sudiwala
Rashmi V
RV
Ade
Peter A R
PA
Griffin
Matthew J
MJ
Wakui
Elley
E
Bhatia
Ravinder S
RS
Lange
Andrew E
AE
Bock
James J
JJ
Turner
Anthony D
AD
Yun
Minhee H
MH
Beeman
Jeffrey W
JW