TY - JOUR
T1 - Multiplicity trigger detector for the SπRIT experiment
AU - SπRIT Collaboration
AU - Kaneko, M.
AU - Murakami, T.
AU - Miwa, K.
AU - Shiozaki, T.
AU - Barney, J.
AU - Cerizza, G.
AU - Estee, J.
AU - Isobe, T.
AU - Jhang, G.
AU - Kurata-Nishimura, M.
AU - Lasko, P.
AU - Lee, J. W.
AU - Łukasik, J.
AU - Lynch, W. G.
AU - Nakatsuka, N.
AU - Pawłowski, P.
AU - Sakurai, H.
AU - Santamaria, C.
AU - Suzuki, D.
AU - Tsang, C. Y.
AU - Tsang, M. B.
AU - Wang, R.
AU - Zhang, Y.
N1 - Funding Information:
This work was supported by the Japanese MEXT KAKENHI (Grant-in-Aid for Scientific Research on Innovative Areas) grant no. 24105004 , the U.S. Department of Energy under grant nos. DE-SC0014530 , DE-NA0002923 , US National Science Foundation under grant no. PHY-1565546 and the Polish National Science Center (NCN) under contract nos. UMO-2013/09/B/ST2/04064 and UMO-2013/10/M/ST2/00624 . One of the authors (M. K.) acknowledges the support from the RIKEN Junior Research Associate Program. The computing resource for the data analysis and simulations were provided by the HOKUSAI GreatWave system at RIKEN. A part of the test experiments was performed as Research Project with Heavy Ions at NIRS-HIMAC under program no. 12H292. The authors also wish to thank the accelerator staff at HIMAC and RIBF for supplying the excellent beams used in this work. The authors thank T2K collaboration for providing their plastic scintillators.
Funding Information:
This work was supported by the Japanese MEXT KAKENHI (Grant-in-Aid for Scientific Research on Innovative Areas) grant no. 24105004, the U.S. Department of Energy under grant nos. DE-SC0014530, DE-NA0002923, US National Science Foundation under grant no. PHY-1565546 and the Polish National Science Center (NCN) under contract nos. UMO-2013/09/B/ST2/04064 and UMO-2013/10/M/ST2/00624. One of the authors (M. K.) acknowledges the support from the RIKEN Junior Research Associate Program. The computing resource for the data analysis and simulations were provided by the HOKUSAI GreatWave system at RIKEN. A part of the test experiments was performed as Research Project with Heavy Ions at NIRS-HIMAC under program no. 12H292. The authors also wish to thank the accelerator staff at HIMAC and RIBF for supplying the excellent beams used in this work. The authors thank T2K collaboration for providing their plastic scintillators.
Publisher Copyright:
© 2022
PY - 2022/9/11
Y1 - 2022/9/11
N2 - A multiplicity trigger detector (MTD) was developed for the SπRIT experiment that aims to probe the high-density symmetry energy via heavy-ion collisions (HICs). The MTD is designed to measure the charged-particle multiplicity in HICs to provide a trigger signal that can be used to select high-multiplicity events induced by central collisions. The MTD consists of two side-walls segmented into 30 plastic scintillation paddles, each equipped with a multi-pixel photon counter. A custom board with EASIROC front-end ASIC is used as readout electronics. A multiplicity logic signal is generated by an on-board FPGA that processes the discriminated signals from EASIROCs. The overall latency of the whole detector system for outputting the trigger is less than 100 ns, including 52 ns of electronics latency for processing the signals. During the measurement of 112Sn+124Sn reactions at an incident energy of 270 MeV/nucleon, the minimum multiplicity threshold of the MTD was set to 4, where the overall trigger efficiency was obtained to be about 39 % for inclusive nuclear reactions. A simulation study with a numerical calculation of HICs found that the central collisions of impact parameters of less than 4 fm can be triggered with a high efficiency of more than 95 % by the experimental trigger condition.
AB - A multiplicity trigger detector (MTD) was developed for the SπRIT experiment that aims to probe the high-density symmetry energy via heavy-ion collisions (HICs). The MTD is designed to measure the charged-particle multiplicity in HICs to provide a trigger signal that can be used to select high-multiplicity events induced by central collisions. The MTD consists of two side-walls segmented into 30 plastic scintillation paddles, each equipped with a multi-pixel photon counter. A custom board with EASIROC front-end ASIC is used as readout electronics. A multiplicity logic signal is generated by an on-board FPGA that processes the discriminated signals from EASIROCs. The overall latency of the whole detector system for outputting the trigger is less than 100 ns, including 52 ns of electronics latency for processing the signals. During the measurement of 112Sn+124Sn reactions at an incident energy of 270 MeV/nucleon, the minimum multiplicity threshold of the MTD was set to 4, where the overall trigger efficiency was obtained to be about 39 % for inclusive nuclear reactions. A simulation study with a numerical calculation of HICs found that the central collisions of impact parameters of less than 4 fm can be triggered with a high efficiency of more than 95 % by the experimental trigger condition.
KW - Central heavy-ion collision
KW - Charged-particle multiplicity
KW - Trigger efficiency
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U2 - 10.1016/j.nima.2022.167010
DO - 10.1016/j.nima.2022.167010
M3 - Article
AN - SCOPUS:85133916450
SN - 0168-9002
VL - 1039
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
M1 - 167010
ER -