Background: In inertial confinement fusion (ICF) experiments

the temperature and density of fusion plasma zone are extremely important parameters requiring to diagnose. Purpose: The aim is to design a circuit for diagnosing the temperature information of the plasma zone. Methods: In order to diagnose the temperature information of plasma zone

neutron time-of-flight method was adopted to measure the neutron energy spectrum

i.e.

to measure the delay time between the signal of the detector and start signal. We designed a program to accurately measure the time-of-flight with constant fraction discrimination (CFD) method

and used the TDC-GP21 (Time Digital Conversion) produced by ACAM Company (Germany) to complete accurate time measurement. Results: Based on the program

the electronics time-resolution of the measurement circuit within 1 500 ns range is higher than 200 ps

and the measurement deviation is smaller than 0.06%. At the same time

the typical result of electronics time-resolution included detector time-resolution is 217.5 ps. Conclusion: The recording capability and measurement accuracy of the circuit designed can meet the needs of practical applications

which could be used in neutron diagnosing. Abstract