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Feb 21 – 25, 2022
Vienna University of Technology
Europe/Vienna timezone

The LiNA experiment: Development of multi-layered time projection chamber

Not scheduled
Vienna University of Technology

Vienna University of Technology

Gusshausstraße 27-29, 1040 Wien
Recorded Presentation Gaseous Detectors


Naoyuki SUMI (KEK)


The neutron lifetime is an important parameter for particle physics and cosmology. There are two types of measurement methods carried out so far, but their results are disagreement with 4.1$\sigma$. In the beam method carried out at J-PARC, a neutron bunch passes through a gaseous detector Time Projection Chamber (TPC). The TPC counts a beta decay electron and a neutron flux by $^3$He(n,p)$^3$H reaction. However, the result of this experiment still has large uncertainty. The largest two contributions of the uncertainty are background contamination and signal cut inefficiency. A new experiment, the LiNA experiment, is proposed to overcome the problems. This system suppresses background events that come from the detector wall and improves signal cut efficiency by applying a uniform magnetic field in parallel to the beam axis. The detector system which has three drift layers was developed at Kyushu University. The detector and magnet integration test was carried out at KEK. The $\beta$-ray source was installed in the center of the detector to imitate the neutron beta decay electron. The $\gamma$-ray source was installed on the side of the detector to evaluate background suppression with the field. It was confirmed that $\beta$-ray is confined while $\gamma$-ray background is suppressed to 1/30 in the signal region. This system can measure the neutron lifetime with an accuracy of 0.2% by 30 days measurement at J-PARC.

Primary experiment LiNA

Primary authors

Naoyuki SUMI (KEK) Go ICHIKAWA (KEK) Kenji MISHIMA (KEK) Masaaki KITAGUCHI (Nagoya Univ. KMI) So MAKISE (Kyushu Univ) Shun MATSUZAKI (Kyushu Univ.) Yasuhiro MAKIDA (KEK) Tomoya NAGANO (Kyushu Univ.) Hidetoshi OTONO (Kyushu Univ. RCAPP) Masaki TANIDA (Kyushu Univ.) Hideaki UEHARA (Kyushu Univ.) Kodai YANO (Kyushu Univ.) Tamaki YOSHIOKA (Kyushu Univ. RCAPP)

Presentation materials