Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
KEK, Ibaraki, Japan
JAEA/J-PARC, Tokai-mura, Japan
KMI, Nagoya, AIchi Prefecture, Japan
Ibaraki University, Ibaraki, Japan
RIKEN Nishina Center, Wako, Japan
JAEA, Ibaraki-ken, Japan
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
Kyoto ICR, Uji, Kyoto, Japan
Sokendai, Ibaraki, Japan
University of Tokyo, Tokyo, Japan
Nagoya University, Nagoya, Japan
J-PARC E34 experiment intends to measure the anomalous magnetic moment and electric dipole moment of muon precisely by a different way from the previous experiment. In this experiment, a low-emittance muon beam is provided using the muons with the thermal energy and the four-stage linac. The demonstration of the first muon RF acceleration with an RFQ linac was conducted and the transverse profile of the accelerated muons was measured last year. As one of the remaining issues for the beam-diagnostic system, the longitudinal beam profile after the RFQ should be measured to match the profile to the designed acceptance of the subsequent accelerator. For this purpose, the new longitudinal beam monitor using the micro-channel plate is under development. The time resolution aims to be around 30 to 40 ps corresponding to 1 % of a period of an operation frequency of the accelerator, which is 324 MHz. On November 2018, the bunch structure of accelerated muons of 89 keV with the RFQ was measured using this monitor at the J-PARC MLF. The latest analysis result of this measurement will be reported in this poster.
KEK, Ibaraki, Japan
JAEA/J-PARC, Tokai-mura, Japan
Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
Ibaraki University, Ibaraki, Japan
Nagoya University, Nagoya, Japan
RIKEN Nishina Center, Wako, Japan
University of Tokyo, Tokyo, Japan
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
Negative muonium ion production is one of methods to cool muons. Since its discovery in 1987 by interactions of muons with a metal foil, it has been discussed that the production efficiency would be improved using a low-work function material. C12A7 (12CaO·7AlO3) was a well-known insulator as a constituent of alumina cement, but was recently confirmed to exhibit electric conductivity by electron doping. The C12A7 electride has lower work function (2.9 eV) and it was reported that nearly the same negative current signal as that with a bi-alkali material coated metal were observed in H− formation. In this poster, the negative muonium production measurement with a Al foil and C12A7 electride film will be presented.