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Hi All,
Reports in John's meeting tomorrow (Tuesday June 28th at 1:30pm):
Beam line status Stepan
Vacuum chamber for tracker Marco
Grounding issues and beam noise pickup Alex
ECAL vacuum chamber Stepan
Target Clive

Grounding issues:
Isolating vacuum chamber may be problem from RF. Noise pickup in silicon sensors inside beam pipe. Is it possible to electrically isolate silicon sensors from vacuum pipe. Stepan points out that the beam current is few hundred nano-amps. Al doesn't think image charge with hurt us. But if Q is >100 or so the noise can build up in resonance mode. Al doesn't think it is a problem. Takashi pointed out that Novokoski calculated power and it is very small-collective effect but Q is very small. Vacuum and beam pipe should be one. Grounding should be carefully done.Cannot isolate vacuum chamber from magnet. Stepan's experience shows that grounding mounting can be controlled. Breaking up vacuum pipe should not be done. John points out that we may need to reduce EM by making a faraday cage around silicon. Beam current small, EMI from metallic structure connected to many noise sources. Only high frequency RF will come down beam pipe. It is hard to make a Klystron. Alex and Ned will make a brief report. Clive asks if we can do mock up using a wire near silicon in air? Stepan will look into possible ways of testing this in the beam line. Mike Woods did End Station A test of silicon. Can we shield detector from beam? Not trivial and can cause other problems.

Target report from Clive: no recent work.

Beam line (Marco and Stepan)
Things ok. Al vs SS. No issue with building it with Al. Progressing with downstream beam line. Upstream with analyzing chamber and coupling to ECAL vacuum progressing.
Wire scanner integrated with target (horizontal and vertical). Wires on detector can be incorporated with silicon. Wire scanner after tracker is y scanner. Stepan points out there is a beam position on faraday cage 40 m downstream. Takashi points out that 1st layer horizontal +-1mm last layer +-5mm.

Ken
emi_sinev.pdf

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