Large-aperture alumina ceramics beam pipes with titanium bellows for the rapid cycling synchrotron at Japan Proton Accelerator Research Complex

Kamiya, Junichiro   ; Kinsho, Michikazu  ; Abe, Kazuhiko*; Higa, Kyusaku*; Koizumi, Oji*

The 3 GeV Rapid Cycling Synchrotron (RCS) in J-PARC aims to generate one of the highest power protons in the world, whose design extraction beam power is 1 MW. Beam pipes of alumina ceramics are used to prevent the induced current, which is caused by the rapid change of the magnetic field. In the beam injection section, ceramics beam pipes for a quadrupole magnet and a horizontal shift bump magnet are connected without bellows due to the very limited space. To improve maintainability, the ceramics beam pipes for the quadrupole magnet were newly designed to insert the bellows. We will report the design concept of the new alumina ceramics beam pipes with low spring constant bellows and the several results of the verification tests.