We had the 1st IP-BPM meeting at 15:00-16:10, 8th May 2006, ATF-LC meeting room.

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

Philippe reported his work for last two weeks. He tried to speak in Japanese. His Japanese could be understood with his slides. It is a good exercise. His presentation is here. Also, we wrote a paper of "An introduction to rectangular Cavity Beam Position Monitors" for his beginning of work.

First, test results of the electronics were reported. The tested electronics consists of three modules of Converter, Limiter & Intensity Detector and Detector with 4 phases as well as phase adjustment" potentiometer. Diagrams of major components are shown in a PDF file, which is extracted from a Honda's note ( pdf, Japanese) .

Present converter is an old one with 600MHz output frequency instead of 714MHz. He showed basic properties of the circuit such as linearity and band pass filter in the Limiter, detector performance with 4 phases, i.e. 0, 45, 90 and 135 degree.

There were following comments;

  1. Zero degree phase must be that of the reference signal.
  2. Results must be presented with measurement errors for quantitative evaluation
  3. To see the linearity, results must be plotted in linear scale on both axes
  4. For test of the Limiter & Intensity Detector; outputs must not depend on the input intensity. So, the minimum input intensity should be measured as threshold of saturation at the limited amplifier.
  5. For test of the 4 phased detector, 714MHz signal should be input from an oscillator.
  6. New converter of 714MHz will be available within a week.
Second, a MAFIA work was shown. The IP-BPM has been modeled in MAFIA. He need a detailed discussion on how to simulate signals with Honda.

Since ATF will be operated in next week, we will make a beam test plan .

We will have the next meeting on 22nd May 2006.