Pulse shape distortion of output signals from single-crystal CVD diamond detector in few-GHz broadband amplifiers

¹ The Institute of Physical and Chemical Research (RIKEN) - 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
² Graduate School of Engineering, Hokkaido University - N13, W8, Kita-ku, Sapporo 060-8628, Japan
³ National Institute of Advanced Industrial Science and Technology (AIST) - 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan

Received: 10 February 2014
Accepted: 7 April 2014

Abstract

The response of a diamond detector made from a single crystal grown by chemical vapour deposition was studied using a broadband amplifier. A short pulse width of for ²⁴¹Am-α-particles was observed with a digital oscilloscope. To discuss pulse shape distortion from the detector in a measurement system, we simulated waveforms with a SPICE simulator using an equivalent circuit model that contained three main parts: detector, amplifier, and oscilloscope. In the simulation, we found that the pulse width spread by more than 200 ps following amplification. We discuss the effects of the detector read-out circuit time constant on the observed waveforms and confirm that the pulse width spread was restrained by use of a short time constant compared with carrier drift time in diamond crystals.