Abstract: A radiation detector comprises an energy/electricity converter having a detection area for detecting incident radiation, and electrodes connecting the converter to an external driving circuit for driving the converter to convert energy of the incident radiation detected by the detection area of the converter into an electric signal. A collimator is integrally connected to the converter and has an opening for transmitting radiation to irradiate the detection area of the converter and portions for preventing radiation from irradiating a part of the converter other than the detection area. A spacer is integrally connected to the collimator and the converter for maintaining a preselected distance between the collimator and the detection area of the converter.

Abstract: There is provided a radiation detector that allows accurate irradiation to a detection area and has a high detection efficiency. A collimator that has an opening for transmitting radiation to irradiate the detection area and a function as a shielding plate for preventing radiation from irradiating a part other than the detection area is installed on the same board that forms an energy/electricity converter (radiation detector). The radiation detector is constructed such that the alignment of the opening of the collimator and the detection area is easy, and the detection area and the opening of the collimator are close so that the detection efficiency is increased.

Abstract: A signal detector has a SQUID, a bias current supply circuit for supplying a bias current to the SQUID, and a drive circuit for detecting a magnetic flux by receiving a voltage signal of the SQUID and reading out the input signal as an output voltage. The drive circuit has two systems including a flux-locked loop system for converting a voltage signal of the SQUID into a current signal and making a magnetic flux inside the SQUID constant by feeding back a signal whereto, and an output system separate from and operating independently of the flux-locked loop system for converting a voltage signal of the SQUID and reading out the converted voltage signal without feeding back a signal to the SQUID.

Abstract: A drive circuit for magnetic flux detection for converting to an output voltage corresponding to an input signal is made up of two systems, being a flux-locked loop system for converting to a current signal corresponding to a voltage signal Vs of a superconducting quantum interference device and making magnetic flux inside a superconducting ring constant by feeding back to a modulation coil as a feedback signal If, and an output system for converting to a voltage signal Vo in response to the voltage signal Vs of the superconducting quantum interference device, and not feeding back to the modulation coil but outputting as an output voltage Vout.