MVD Pedestal noise

In addition to problems with pedestal shifts (listed as a separate problem here) some of MCMs have too much noise. We do not fully understand this, but at least part of the problem seems to be noise which is picked up on the kapton cable from the Silicon detector to the MCM. The evidence for this is shown on this web page created by SangSu which shows that the width of the pedestal depends on the length of this cable. SangSu also saw that the noise was not reduced when the photon converter (a few mm of Brass wrapped around the outside of the MVD) was installed -- look here for those plots. This implies that the noise comes from someplace inside the MVD enclosure (or perhaps the beam pipe).

We believe, or at least hope, that by shielding these Kapton cables we can reduce this noise. The noise increases with the length of the cable. It happens that this is also orders the cables in terms of distance from the beam pipe -- the longest cable is closest to the beam pipe, next comes the 2nd longest, 3rd longest, and finally the shortest cable is farthest from the beam pipe. This may be relevant too.