上海科技大学知识管理系统

Photon counting X-ray detector (PCXD) has the capability to distinguish each individual photon interacting with the detector. The combination of detector, charge sensitive amplifier (CSA), and shaper is used to provide a waveform to be compared with pre-set reference voltages and counted by counters when exceeding reference voltages. The waveform is related to the shaping time. To achieve high count rate, the shaping time of the shaper should be shorter, but a shorter shaping time will cause a negative impact on the energy resolution. This paper proposes a new adjustable structure of the shaper, which introduces a switch network as a part of the shaper. As a result, the shaper can adjust the shaping time according to the X-ray photon flux rate known as dose rate. Through the simulation of the shaper in the electronic design automatic (EDA) software, results demonstrate that different control signals acting on the switch network can affect the output waveform of the shaper.