First demonstration of an emulsion multi-stage shifter for accelerator neutrino experiments in J-PARC T60

Abstract

We describe the first ever implementation of an emulsion multi-stage shifter in an accelerator neutrino experiment. The system was installed in the neutrino monitor building in J-PARC as a part of a test experiment T60 and stable operation was maintained for a total of 126.6 days. By applying time information to emulsion films, various results were obtained. Time resolutions of 5.3 to 14.7 s were evaluated in an operation spanning 46.9 days (time resolved numbers of 3.8-1.4×10 5 ). By using timing and spatial information, a reconstruction of coincident events that consisted of high multiplicity events and vertex events, including neutrino events was performed. Emulsion events were matched to events observed by INGRID, one of near detectors of the T2K experiment, with high reliability (98.5%) and hybrid analysis was established via use of the multi-stage shifter. The results demonstrate that the multi-stage shifter is feasible for use in neutrino experiments.

Measurements of protons and charged pions emitted from $ν_μ$ charged-current interactions on iron at a mean neutrino energy of 1.49$\,$GeV using a nuclear emulsion detector

“…[20]. The detector is a hybrid apparatus composed of an irontarget emulsion cloud chamber (ECC), an emulsion multistage shifter (Shifter) [21][22][23][24][25], and an interactive neutrino grid (INGRID) [26,27] at the center of the neutrino beam (on-axis). The ECC comprises 12 basic units called bricks, each of which is composed of 23 emulsion films interleaved with 22 iron plates.…”

First measurement of ν¯μ and νμ charged-current inclusive interactions on water using a nuclear emulsion detector

“…For track matching between the ECC and INGRID, another device with time and position resolutions is required, because the angular and position resolutions of INGRID are not sufficient to select a track candidate in the ECC to be connected to an INGRID track. In some cases, an emulsion shifter [30,33] is used to apply time stamps to tracks in the ECC. However, in this pilot run, the SFT is employed as a time stamper, because it can provide more precise time information than the emulsion shifter.…”

“…A series of pilot experiments has been carried out by the NINJA Collaboration beginning in 2014 [29,30]. This paper reports the results of a pilot run with a small-mass water target (J-PARC T68).…”

GRAINE project and first results on 2018 balloon-borne experiment

“…Starting at 14:48, the operation mode was changed to 10 µm/s speed in the third stage to cover the Vela pulsar in 45 degree zenith with a timing resolution of sub-second which has enough resolution to image Vela pulsar with 1 degree above 100 MeV aimed in this experiment. The operation parameters were based on an operation in accelerator neutrino experiment, J-PARC T60 [10]. The operation ended at 22:15.…”