• D. Okamoto
  Tohoku University, Graduate School of Science, Sendai
• Y. Honda, T. Tauchi
  KEK, Ibaraki
• T. Sanuki
  Tohoku University, School of Scinece, Sendai

We have stud­ied a beam orbit tilt mon­i­tor for sta­bi­liz­ing the beam orbit in ATF2. Once we can mea­sure a beam orbit tilt with high pre­ci­sion at one point, we can re­late this data with the beam po­si­tion pro­file at the focal point. A tilt mon­i­tor is com­posed of a sin­gle rect­an­gu­lar sen­sor cav­i­ty and a waveg­uide to ex­tract the sig­nal. In the sen­sor cav­i­ty, there is the most basic res­o­nant mode called monopole mode. This monopole mode is per­pen­dic­u­lar to the nom­i­nal beam axis, and ex­cit­ed by the beam tilt. We ex­tract this monopole mode. As the re­sult, the am­pli­tude of the ex­tract­ed sig­nal is pro­por­tion­al to the tilt angle. The tilt mon­i­tor is al­most in­dep­ne­dent with beam pos­tion, so we can get the tilt date in­de­pen­dent­ly. Ac­cord­ing to our sim­u­la­tion, the sen­si­tiv­i­ty is es­ti­mat­ed about 35n­rad in the ver­ti­cal di­rec­tion. The pro­to­type was com­plet­ed and in­stalled in the test area on the ATF2 beam­line. The first beam test will be per­formed in De­cem­ber 2009. We will re­port this re­sult and fu­ture up­date plan.

Slides