M. Kishimoto et al., HIGH-RESOLUTION X-RAY-DETECTION BY NB-BASED STJ AND 4-JFETS LOW-NOISEAMPLIFIER, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 370(1), 1996, pp. 126-127
We have made up a low noise charge sensitive amplifier with cooled 4-J
FETs for a large area superconducting tunnel junction (STJ). These JFE
Ts were operated at about 130 K. Each JFET (2SK190) dissipates about 1
5 mW. A high energy resolution of 73 eV for 5.9 keV X-rays and 61 eV f
or pulser signals have been achieved with a 178 mu m X 178 178 mu m Nb
/Al-AlOx/Al/Nb STJ having a junction capacitance of 1900 pF.