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Description
Method for increasing the efficiency of registration of minimum ionizing particles by fast detector on microchannel plates.
F.F.Valiev, N.I.Kalinichenko, A.Kozhedub, N.A.Makarov, V.N.Popov, G.A.Feofilov
St. Petersburg State University
Fast detectors on the microchannel plates (MCPs) have high time characteristics (short pulses of ~2 ns at the base, with a front at < 800 ps). They were proposed earlier [1] for registration of minimum ionizing particles (MIPs) formed in nucleus-nucleus collisions, the event-by-event determination of the start signal (T0), the primary vertex position and for the suppression of events of collisions with residual gas in the beam pipe. In addition, it was shown in [2] with machine learning algorithms that the event-by-event analysis of the centrality of collisions of relativistic nuclei is also possible using time-of-flight information from the MCP detectors. It is especially important in the search for critical fluctuations in the MPD experiment at the NICA collider. MCP detectors have a large intrinsic gain, which in the case of a chevron assembly reaches values of ~106, 107. However, this advantage results in an increase in its own noise (the dark current of the MCP). Therefore, the detection thresholds should be introduced leading, as a result, to some decrease in the efficiency of detectors on the MCP (to ~ 80%) [3].
In this paper, we propose a method to increase the detection efficiency of MIPs while simultaneously reducing the background of the detecting device by several orders of magnitude. We show that by reducing the registration thresholds and introducing a nanosecond considence scheme for signals from two MCP detectors mounted in series on the MIP trajectory, it is possible to obtain an increase in the detection efficiency of minimally ionizing particles (~95%) with a simultaneous decrease in the background (less than ~10-3 1/(sec . cm2)). The possible application of this low-noise detector for recording cumulative particles in experiments at the NICA collider is discussed.
The authors acknowledge Saint-Petersburg State University for a research project 103821868
[1] A. A. Baldin, G. A. Feofilov, P. Har’yuzov, and F. F. Valiev,, “Fast beam-beam collisions monitor for experiments at NICA,” Nucl. Instr. Methods Phys. Res., Sect. A 958, 162154 (2020).
[2] K. Galaktionov, V. Rudnev , and F. Valiev , “Application of Neural Networks for Event-by-Event Evaluation of the Impact Parameter “, Physics of Particles and Nuclei, 2023, Vol. 54, No. 3, pp. 446–448.
[3] F.F.Valiev et al.“Microchannel plates as a detector for 800 MeV/c charged pions and protons “ JINR Rapid Communications. 1991. No 4/50/-91. p.27-36
