Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 1712.06351

Fundamental physics activities with pulsed neutron at J-PARC(BL05)

Kenji Mishima·Shogo Awano·Yasuhiro Fuwa·Fumiya Goto·Christopher C. Haddock·Masahiro Hino·Masanori Hirose·Katsuya Hirota·Sei Ieki·Sohei Imajo·Takashi Ino·Yoshihisa Iwashita·Ryo Katayama·Hiroaki Kawahara·Masaaki Kitaguchi·Ryunosuke Kitahara·Jun Koga·Aya Morishita·Tomofumi Nagae·Naoki Nagakura·Naotaka Naganawa·Noriko Oi·Hideyuki Oide·Hidetoshi Otono·Yoshichika Seki·Daiichiro Sekiba·Tatsushi Shima·Hirohiko M. Shimizu·William M. Snow·Naoyuki Sumi·Hirochika Sumino·Satomi Tada·Kaoru Taketani·Seiji Tasaki·Tatsuhiko Tomita·Atsuhiro Umemoto·Takahito Yamada·Satoru Yamashita·Mami Yokohashi·Tamaki Yoshioka
View original source ↗Read source document ↗Export metadata ↓

Abstract

"Neutron Optics and Physics (NOP/ BL05)" at MLF in J-PARC is a beamline for studies of fundamental physics. The beamline is divided into three branches so that different experiments can be performed in parallel. These beam branches are being used to develop a variety of new projects. We are developing an experimental project to measure the neutron lifetime with total uncertainty of 1 s (0.1%). The neutron lifetime is an important parameter in elementary particle and astrophysics. Thus far, the neutron lifetime has been measured by several groups; however, different values are obtained from different measurement methods. This experiment is using a method with different sources of systematic uncertainty than measurements conducted to date. We are also developing a source of pulsed ultra-cold neutrons (UCNs) produced from a Doppler shifter are available at the unpolarized beam branch. We are developing a time focusing device for UCNs, a so called "rebuncher", which can increase UCN density from a pulsed UCN source. At the low divergence beam branch, an experiment to search an unknown intermediate force with nanometer range is performed by measuring the angular dependence of neutron scattering by noble gases. Finally the beamline is also used for the research and development of optical elements and detectors. For example, a position sensitive neutron detector that uses emulsion to achieve sub-micrometer resolution is currently under development. We have succeeded in detecting cold and ultra-cold neutrons using the emulsion detector.

Explore related subjects

physics.ins-dethep-ex

Keep this discovery

BibTeXRIS

Kenji Mishima, Shogo Awano, Yasuhiro Fuwa, Fumiya Goto, Christopher C. Haddock, Masahiro Hino, Masanori Hirose, Katsuya Hirota, Sei Ieki, Sohei Imajo, Takashi Ino, Yoshihisa Iwashita, Ryo Katayama, Hiroaki Kawahara, Masaaki Kitaguchi, Ryunosuke Kitahara, Jun Koga, Aya Morishita, Tomofumi Nagae, Naoki Nagakura, Naotaka Naganawa, Noriko Oi, Hideyuki Oide, Hidetoshi Otono, Yoshichika Seki, Daiichiro Sekiba, Tatsushi Shima, Hirohiko M. Shimizu, William M. Snow, Naoyuki Sumi, Hirochika Sumino, Satomi Tada, Kaoru Taketani, Seiji Tasaki, Tatsuhiko Tomita, Atsuhiro Umemoto, Takahito Yamada, Satoru Yamashita, Mami Yokohashi, Tamaki Yoshioka. 2017-12-18. Fundamental physics activities with pulsed neutron at J-PARC(BL05). https://doi.org/10.7566/jpscp.22.011033

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

High-Speed Semi-FE Readout Module for ATLAS MDT at HL-LHC: Design and Production-Level Characterization

The High-Luminosity upgrade of the Large Hadron Collider (HL-LHC) introduces increased demands on the ATLAS Muon Spectrometer, particularly in terms of data throughput, timing distribution and system reliability. The Phase-II Chamber Service Module (CSM) is a key component of the upgraded Monitored Drift Tube (MDT) trigger and readout system, providing a high-speed interface between the front-end electronics and the backend systems. This paper describes the design and implementation of the Phase-II CSM, together with its validation. The results show that the CSM supports two independent optical uplinks, each operating at a line rate of 10.24 Gbps, together with clock distribution and slow control in the expected operating environment. Integration with small-diameter MDT (sMDT) chambers and tests with the prototype L0MDT trigger system are also presented. The CSM boards are now in production and will be used for installation and integration during the upcoming LHC Long Shutdown.

physics.ins-det↗
arXiv2026

Spectral Discrimination of Deposited Gamma-Ray Energies in a Simulated CeBr$_3$ Scintillator

We show that wavelength measurements of individual detected optical photons may provide additional information about gamma-ray energy deposited in a CeBr$_3$ crystal when the detected-photon-count distributions overlap for nearby gamma-ray energies. Monoenergetic 662 and 629 keV gammas are used in a Geant4 simulation of a $25\times25\times20~\mathrm{mm^3}$ CeBr$_3$ crystal. Assuming a light yield of $6.0\times10^4$ photons/MeV, a wavelength-independent photon-detection efficiency of 30%, and a wavelength resolution of $\sigma_{\lambda}=40$ nm, we find that the fraction of photons reconstructed above 385 nm gives an event-level separation of $\sim$ 2 standard deviations between the 662 and 629 keV event populations selected within the same $\sim$ 1%-wide detected-photon-count interval. No timing or reconstructed interaction-position information is used. The result demonstrates, within the present simulation model, that event-dependent optical spectra can retain energy information beyond an undifferentiated photon count.

physics.ins-det↗
arXiv2026

Operation of a negative ion gas time projection chamber without electronegative fill gases

The high fidelity reconstruction of particle tracks in micropatterned gaseous time projection chambers renders this technology ideal for future rare-event searches, including direction-sensitive dark matter experiments. Large drift distances are typically required for such experiments, so that the overall spatial resolution is limited by diffusion. Negative ion drift exhibits lower diffusion than electron drift and is thus an attractive option for realising a large-scale detector. The use of electronegative gases to create negative ions introduces technical challenges, most notably a reduction in gain when compared to conventional gas mixtures. In this study, we demonstrate a new method for negative ion generation via dissociative electron attachment using the conventional molecular fill gas CF$_4$. Our optical measurements of negative ion drift indicate electron attachment lengths of $<$1 mm and comparable gain to electron avalanches. The individual negative ion avalanches were also time-resolved, allowing the number of ions reaching the readout to be counted. We measure an improved energy resolution by single ion counting, relative to an integrated electron avalanche signal measured under identical gain conditions.

physics.ins-det↗