Development and performance of a secondary electron detector based on a MCP

Abstract

Secondary electron detector (SED) is a key component used in the fission product yield experiment to mark the start time of fission events. The signal to noise ratio and timing characteristics has an important impact on the mass resolution for measuring fission fragments. In this paper, a novel design of secondary electron detector based on MCP was proposed to measure the secondary electrons emitted from fission target. Based on the alpha particles and the fission fragments emitted from ²⁵²Cf source, the response of SED and SCVD diamond are obtained by using a digitizer of 10 bit and 1 ​G samples/s. The rise time of alpha particles and fission fragments are 1.8 ns and 1.7 ns, while the pulse width of which is 4.5 ns and 9.7 ns, respectively. Using the time of flight method and digital constant fraction algorithm, the time resolution of "SED ​+ ​sCVD diamond detector" system for 6.1 ​MeV alpha particles from ²⁵²Cf is obtained as 242 ± 4.7 ps, while that of SED detector is about 171 ± 2.4 ps. The total transition length and time of secondary electron (SE) in the detector are 15.79 cm and 5.97 ns, respectively.