Noise and signal analysis of Ir/Au TES with asymmetrical slits parallel to the electric current

• Published in: IEEE transactions on applied superconductivity Vol. 15; no. 2; pp. 522 - 525
• Main Authors: Fukuda, D., Takahashi, H., Kunieda, Y., Zen, N., Ohkubo, M., Nakazawa, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.06.2005; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Arrays; Asymmetry; Circuit noise; Current measurement; Electric current; Electronics; Exact sciences and technology; Excess noise; Feedback; Frequency measurement; Gold; imaging; Iridium; low temperature detectors; Low-frequency noise; Noise; Optical imaging; Optoelectronic devices; Performance analysis; Pixels; position sensitive detectors; precise energy measurement; radiation detectors; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Signal analysis; Slits; Studies; X-ray imaging; X-rays; Performance evaluation; Excess noise; Feedback regulation; Temperature sensor; Position sensitive detector; 1/f noise; X ray irradiation; Thermoelectric properties; low temperature detectors; Radiation detector; Energy resolution; Bias voltage; Imaging; Signal processing; radiation detectors; position sensitive detectors; Signal analysis; Electric current; precise energy measurement; Low temperature
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2005.849896

A multi-pixel TES array is one of the attractive methods to read-out the incident x-ray position, which simplifies a read-out circuit for imaging applications. We fabricated a ten-pixel Ir/Au TES microcalorimeter with asymmetrical slits parallel to the electric current, and analyzed its noise and signal characteristics. The device was successfully operated in a strong electro-thermal feedback (ETF) mode. However, very large excess noise is observed, which cannot be explained by the noise theory for a single pixel TES. We have modeled the multi-pixel TES array as separated thermal group components, and analyzed noise performance theoretically. As a result, the current noise in our theory is well agreed with the measured noise at a low frequency below 3 kHz. From the x-ray irradiation measurements, ten divided signal groups are observed, which will be associated with the incident x-ray position pixel. The best energy resolution was 18 eV (FWHM) for 5.9 keV x-rays at 0.5 /spl mu/V bias voltage.