KEK, Ibaraki, Japan
RIKEN Nishina Center, Wako, Japan
TRIUMF, Vancouver, Canada
KEK, Ibaraki, Japan
SNU, Seoul, Republic of Korea
JAEA/J-PARC, Tokai-mura, Japan
Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
Ibaraki University, Ibaraki, Japan
RIKEN Nishina Center, Wako, Japan
University of Tokyo, Tokyo, Japan
The University of Tokyo, Graduate School of Science, Tokyo, Japan
Budker INP & NSU, Novosibirsk, Russia
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
Korea University, Seoul, Republic of Korea
The E34 experiment aims to measure muon anomalous magnetic moment with a precision of 0.1ppm. The experiment utilizes low emittance muon beam with a muon linac to sweep out beam related uncertainties, which limit the g-2 precision in past experiments. A beam matching with precise beam measurements is required to avoid substantial emittance growth and satisfy the experimental requirement on the beam emittance of around 1.5 pi mm mrad. We conduct profile measurement of muon after acceleration with a radio-frequency quadrupole (RFQ) on December 2017 following a first muon acceleration experiment on October. In the experiment of profile measurement, epi-thermal negative muonium ions are generated by injecting surface muons to a thin metal foil. The muonium ions are accelerated to 5 keV. by an electro-static lens and accelerated to 90 keV by the RFQ. Then the muonium ions are transported to a profile detector consisting of a micro-channel plate and a ccd camera via a quadrupole pair and a bending magnet. In this poster, the experimental result and comparison to the simulation are reported.
JAEA/J-PARC, Tokai-mura, Japan
SNU, Seoul, Republic of Korea
KEK, Ibaraki, Japan
RLNR, Tokyo, Japan
Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
Ibaraki University, Ibaraki, Japan
RIKEN Nishina Center, Wako, Japan
Kyoto ICR, Uji, Kyoto, Japan
NIRS, Chiba-shi, Japan
University of Tokyo, Tokyo, Japan
The University of Tokyo, Graduate School of Science, Tokyo, Japan
Budker INP & NSU, Novosibirsk, Russia
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
J-PARC is developing the reacceleration system of the ultra slow (30 meV) muon (USM) obtained by two-photon laser resonant ionization of muonium atoms. The muon beam thus obtained has low emittance, meeting the requirement for the g-2/EDM experiment. J-PARC E34 experiment aims to measure the muon anomalous magnetic moment (g-2) with a precision of 0.1 ppm and search for EDM with a sensitivity to 10-21 e cm. The USM's are accelerated to 212 MeV by using a muon dedicated linac to be a ultra cold muon beam. The muon LINAC consists of an RFQ, a inter-digital H-mode DTL, disk and washer coupled cell structures, and disk loaded structures. The ultra-cold muons will have an extremely small transverse momentum spread of 0.1% with a normalized transverse emittance of around 1.5 pi mm-mrad. Proof of the slow muon acceleration scheme is an essential step to realize the world first muon linac. In October 2017, we have succeeded to accelerate slow negative muoniums generated using a simpler muonium source to 89 keV. In this talk, present design of the muon linac and the result of the world first muon acceleration experiment are reported.
