Fast beam–beam collisions monitor for experiments at NICA

Abstract

Two compact detector systems are proposed to meet the challenges of the fast beam–beam collisions monitoring, event selection and the precise timing determination in proton–proton and nucleus–nucleus collisions at NICA. Beam Position Monitor (BPM) and Fast Beam–Beam Collision (FBBC) monitor are capable to provide the information for each bunch crossing both on the beams location and on the intensity of collisions, as well as on the azimuthal distribution of the particles in the event. The systems are using fast Micro Channel Plate detectors (MCPs). The ultra-high vacuum (UHV) compatibility and low-mass compact design of the BPM and FBBC components allow one to consider their application inside the vacuum beam line of NICA collider. The BPM is based on the effect of the residual gas ionization and provides the high accuracy, fast, bunch-by-bunch measurements of the beam location. The FBBC uses the concept of the fast isochronous timing for the multi-pad readout of short (∼1ns) MCP signals, produced by the particles in the collisions of the beams. Studies of the polarization phenomena in light- and heavy-ion interactions at NICA beams is another goal of research at NICA, and the FBBC is also considered for the local polarimetry at the SPD. In this report we present the results of model simulations and tests of the new prototypes of the fast MCP readout set-ups that are proposed for NICA.