Fast APD Detector with a Short Tail in the Timing Response for an Experiment Using Synchrotron Radiation X-ray Beam

Abstract

We developed a fast X-ray detector system for a nuclear resonant scattering experiment of thorium-229. The system employs silicon avalanche photo-diode as a fast X-ray sensor. The design of the system mainly focuses on the small tail of the timing response in a high rate condition. To reduce the tail component, the system acquires three parameters for each single X-ray photon: the constant fraction timing, the trailing edge timing with a fixed threshold, and the pulse height. The performance of the system was investigated in KEK-PF. A quite small tail of 10 −9 level at 0.5 ns apart from the peak was achieved by using the correlation between the pulse height and the pulse width information.

Development of a measurement system enabling the reconstruction of γ-ray time spectra by simultaneous recording of energy and time information

“…Therefore, it is required to develop a flexible measurement system that fulfils these demands to advance quantum information research using Mössbauer γ-ray photons. Recently, a system for time spectrum measurement with a high speed multi-channel scaler (MCS) has been developed 5) , which has been used for time spectrum measurement of the 26.27-keV level of 201 Hg excited by synchrotron radiation 6) .…”

“…The other signal is input to an amplitude to time converter (ATC), which outputs a logic signal with a delay proportional to the pulse height of the input analog signal. 5) . We used a MCS, which measures absolute time for five input channels with 100 ps time resolution (MCS6, FAST ComTec).…”