TY - JOUR
T1 - Current dependence of performance of TES microcalorimeters and characteristics of excess noise
AU - Takei, Y.
AU - Fujimoto, R.
AU - Ishisaki, Y.
AU - Morita, U.
AU - Tanaka, K.
AU - Koga, T.
AU - Mitsuda, K.
AU - Ohashi, T.
AU - Yamasaki, N. Y.
AU - Iyomoto, N.
AU - Ichitsubo, T.
AU - Sato, K.
AU - Fujimori, T.
AU - Oshima, T.
AU - Futamoto, K.
AU - Shinozaki, K.
AU - Morooka, T.
AU - Nakayama, S.
AU - Yoshida, K.
AU - Takai, N.
AU - Chinone, K.
N1 - Funding Information:
This work was supported in part by MEXT/JSPS, Japan (KAKENHI 13440079, 14204017, 14079103).
PY - 2004/3/11
Y1 - 2004/3/11
N2 - We are developing transition edge sensor (TES) microcalorimeter arrays for future Japanese astronomy missions. Although 6.6 eV energy resolution for 5.9 keV and 74 μs decay time are achieved, our energy resolution was limited by the excess noise of unknown origin. The dominant noise showed 1/R dependence and it only appeared when the current through the TES, I, is larger than 10 μA. This is explained if we assume a constant voltage noise source with a level of ∼2(4kTCRn)1/2. We also investigated the influence of I on the TES performance and found the TES sensitivity α is reduced when the ratio of current to the critical current I/IC is large. It can explain the reduction of α observed when operated without a magnetic shield. We also found a strong correlation between IC and α or the baseline width. Thus, we conclude that IC is an essential parameter for the TES performance.
AB - We are developing transition edge sensor (TES) microcalorimeter arrays for future Japanese astronomy missions. Although 6.6 eV energy resolution for 5.9 keV and 74 μs decay time are achieved, our energy resolution was limited by the excess noise of unknown origin. The dominant noise showed 1/R dependence and it only appeared when the current through the TES, I, is larger than 10 μA. This is explained if we assume a constant voltage noise source with a level of ∼2(4kTCRn)1/2. We also investigated the influence of I on the TES performance and found the TES sensitivity α is reduced when the ratio of current to the critical current I/IC is large. It can explain the reduction of α observed when operated without a magnetic shield. We also found a strong correlation between IC and α or the baseline width. Thus, we conclude that IC is an essential parameter for the TES performance.
KW - Microcalorimeter
KW - Transition-edge sensor (TES)
KW - X-rays
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U2 - 10.1016/j.nima.2003.11.262
DO - 10.1016/j.nima.2003.11.262
M3 - Article
AN - SCOPUS:12144285771
SN - 0168-9002
VL - 520
SP - 340
EP - 343
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
IS - 1-3
ER -