Speaker
Description
Takeyuki Ihara$^A$, Takashi Nakamura$^A$, Shutaro Hanai$^A$, Satoshi Adachi$^C$,
Shunsuke Fujimura$^A$, Koki Ito$^B$, Jyunsei Iwaki$^A$, Shumpei Koyama$^B$, Kazuki Kyo$^B$, Yasuto Makimura$^A$, Vskchintamani Sai Sisir Chandrachud Malladi$^A$, Kenjiro Miki$^B$, Yuma Ohsawa$^A$, Hideaki Otsu$^D$, Yoshiteru Sato$^A$, Yuhei Shimizu$^B$, Hiroo Umetsu$^B$,
$^A$Department of Physics. Institute of Science Tokyo,
$^B$Department of Physics. Tohoku University, $^C$RARiS. Tohoku University,
$^D$RIKEN Nishina Center
We aim to observe tetra-neutrons and hexa-neutrons by measuring all the emitted neutrons coincidence to reconstruct the invariant mass. However, the coincidence measurement of multiple neutrons is still challenging. Therefore, we are developing a new-scheme neutron detector array called NEOLITH. NEOLITH combines a plastic scintillator array with drift chambers which can trace recoil protons, enabling it to efficiently eliminate crosstalk events. Simulations have confirmed its capability to measure up to six neutrons in coincidence.
In this presentation, we report on the introduction of a new method to improve NEOLITH's position resolution. To achieve this, we developed a method to determine the reaction position of a neutron within the plastic scintillator using energy loss information within the scintillator, instead of the original assumption of the position being halfway through the thickness.
To test this method, an experiment was conducted at Tohoku University's RARiS facility. A 50 MeV proton beam was used to generate a neutron beam via the 7Li(p,n)7Be reaction. We used two plastic scintillator modules for NEOLITH and a standard drift chamber. We discuss the analysis results from the Tohoku University experiment where this method was applied.