The Research Of A Low Noise, Wide Dynamic Range And Small Dimension Front-End Circuit

Along with the continuous development of nuclear physics and particle physics,particle detectors get great improvements on the position resolution, the timeresolution and the counting rate. The equivalent noise of the front-end circuit must below to satisfy the request of detectors. And the charge sensitive preamplifier(CSA) ofthe front-end circuit should have a wide dynamic range so that the output of the CSAwon’t be saturated at the high counting rate. For this reason, this scientific researchproject focuses on noise reduction and dynamic range extension. And the front-endcircuit can be applied to signal processing of semiconductor detectors,photomultipliers and electrons multipliers.The front-end circuit is made up of a charge sensitive preamplifier, a mainamplifier and a single channel pulse height analyzer. The equivalent input noise isunder1.5keV. The integral nonlinearity is less than0.11%for the dynamic range of0~±11V. The front-end circuit is compatible with the counting rate of106when theenergy of rays is1MeV and the front-end circuit is at a low cost with a simplestructure. The circuit can be suitable for different applications by combiningdifferent modules. The energy resolution of1.23%was achieved for5.157MeVα-rays from a239Pu source with the charge sensitive preamplifier, the main amplifierand a Au-Si surface barrier detector designed by the Institute of Modern Physics. The energy resolution of7.9%was achieved for1.332MeV γ-rays from a60Cosource with the main amplifier, the single channel pulse height analyzer and a CsIscintillator detector designed by the Institute of Modern Physics.The front-end circuit has the features of wide output dynamic range, simplestructure, high integration, small dimension, low noise, and excellent stability. It hasa great prospect in application.