We had the 2nd IP-BPM meeting at 10:00-11:30, 23rd May 2006, 325, 3-gokan, KEK.

Participants: P.Doublet, Y.Honda, T.Hino and T. Tauchi

Philippe reported his work for last two weeks. His presentation is here. Also, he wrote a paper of "First Simulation of IP-BPM with MAFIA" for his beginning of work.

First he presented the progress report of MAFIA study on electromagnetic properties of the IP-BPM. The MAFIA results on the basic parameters such as the resonance frequencies are consistent with the design values. Intensities of dipole modes are calculated to be linear around the cavity center, Also, the MAFIA shows that resonant frequency of the X wave guide is very similar to that of the cavity in X (horizontal) direction.The X wave guide design has been changed in the hot (vacuum) model by Y.Honda. It was pointed out that the beam intensity is (1 - 0.6)x1010/bunch at ATF, while the beam intensity was set to be 2 x 1010 in his calculation. The present results are not satisfactory since the mesh size seems to be too large, 1-2mm, in MAFIA to see nanometer scale. He will reduce the mesh size to see a few μm scale at least. Also he is advised to discuss with Hino who has used a different 3D program for cavity-BPM at STF.

Second, he reported results of the electronics test including a new converter with 714MHz output. In this test, the electronics modules ( converter, limiter and detector ) were individually checked. There were following comments;

  1. Converter results : Why are the results (gains and slopes) different in the reference and the sensor parts, which are same in the design ?
  2. Limiter results : The input intensity must be adjusted within a range of the limited amplification,i.e from -19dBm to 2dBm.
  3. Detector results :

We will have a Thursday day shift for measurement of the angular effect with phase detection in the cavity-BPM, for 9:00 - 17:00, 25th May.

We will have the next meeting on 6th June 2006.