Difference: DetectorRepair (1 vs. 11)

Brendan's original bad wire report

ePC2 has been disassembled in order to repair the broken wires. We have looked through run 11 for other hot spots / hot wires that we should check while the chamber is open.

Anode sectors should have 32 wires , I label the wires 1-32. As we go around, in the direction of increasing sector, I start with wire 1 and end with wire 32: Wire 1, Sector 1--Wire 32, Sector 1 -->Wire 1, Sector 2--Wire 32, Sector 2, etc...

Cathode sectors have 16 wires. The same convention is used.

Additionally, anode sectors are denoted with an A, while cathode sectors are denoted with a C.

See the attachment in http://www.npl.uiuc.edu/elog/mucap/run11/83 for the mapping. See also the explanations in andi.pdf.

<-- /editTable -->

Andi's reports

• 11/14/07
• 11/26/07

Extraction of the "dead spot" wires

After consulting with Steven, I have determined how the mapping is setup and slightly tweaked the cathode settings Based on the Illinois analysis code, it appears the dead spot centered around z = +50 mm, phi = 3 radians corresponds to the following wires and sectors:

• Anodes: 2701->2750 (Sectors A2, A1)
• Inner Cathodes: 3242->3269 (Sectors C10 and C11, a little of C9)
  • wire 3242 has (z=+94 when phi = 2.8 and z=+191 when phi = 3.1)
  • wire 3269 has (z=-78 when phi = 2.8 and z=+19 when phi = 3.1)
• Outer Cathodes: 3882->3912 (Sectors C23, C22 and C21 -- half of C23,C21, all of C22)
  • wire 3882 has (z=-102 when phi = 3.1 and z = -7.6 when phi = 2.8)
  • wire 3912 has (z=+84 when phi = 3.1 and z= +179 when phi = 2.8)

• The peak of the intersection should be A2xC10xC22

• ePC2 inefficiency:
  

• The 2nd image comes from run 10. It shows the location of the anodes in question. The Inner Cathode 9-10 boundary has also been drawn. The inefficient lines are projections of the ePC1 cathodes, which are not parallel to the ePC2 cathodes.
• By looking up the specifications of ePC2 from, http://www.npl.uiuc.edu/exp/mucapture/coll/epc2/Specifications.doc , I have determined that the blue lines represent the position of the cathodes:
  e.g. length of 800 and angle of 44.308 degrees means that the displacement along the circumference is 800* tan (44.308) ~ 781 mm
  Since the diameter of the inner cathodes is 632 mm, the displacement in phi over the length of the wire is 781/324 ~ 2.47 radians
  The blue lines have such a displacement in phi, whereas the inefficient "stripes" seem to be more like 4 radians.
• Efficiency with sectors labeled:
  

• The 2nd image comes from run 10. It shows the location of the anodes in question. The Inner Cathode 9-10 boundary has also been drawn, however it does not appear to be parallel to the inefficient lines. This needs further understanding.

• Inner Cathodes: 3242->3269

• Outer Cathodes: 3902->3932 (Sectors C21,C22)

<-- /editTable -->