1. 1 HBD HV Status Update Jason for the HBD crew Jan 30, 2007

2. WESTEAST 2 1 3 0 5 4 NORTH SOUTH 26 Jan 2007 Bertan Status T : ---------------- M: ---------------- B : ---------------- T:~4μA @500V M: ---------------- B : ---------------- T:~8μA @500V M: ---------------- B : ---------------- T : ---------------- M: ---------------- B : ---------------- T:~4μA @500V M: ---------------- B : ---------------- T:~7μA @534V M: ---------------- B : ---------------- T:~15μA @520V M: ---------------- B : ---------------- T : ---------------- M: ---------------- B : ---------------- T:~11μA @537V M: ---------------- B : ---------------- T:410nA @535V M: ---------------- B : ---------------- T:~12μA @524V M: ---------------- B:~26μA @520V T:~20μA @529V M: ---------------- B : ---------------- T : ---------------- M: ---------------- B:~26μA @550V T:~23μA @520V M: ---------------- B : ---------------- T:~11μA @430V M: dead 20MΩ B : ---------------- T : ---------------- M: dead 20MΩ B : ---------------- T : ---------------- M: dead 20MΩ B:~9μA @550V T:~24μA @550V M: ---------------- B : ---------------- T:~22μA @550V M: ---------------- B : ---------------- T:~37μA @500V M: ---------------- B : ---------------- T:700nA @500V M: ---------------- B : ---------------- T : ---------------- M: dead 20MΩ B : ---------------- inf resistance20MΩ T:540nA @500V M:76μA @500V B:51μA @520V T : ---------------- M:~46μA @300V B : ----------------

3. 30 Jan 2007 LeCroy Status more-or-less consistent with Bertan tests… exceptions: WN0, draws less current inf res on 13.5M  short WS2, draws less current 20M  on mid (dead?) 10M  on 60M  short ES4, draws more current 20M  on 25M  short Many GEMs seem to improve over time. WS3, EN2 draw high current and trip. EN0 has a bad cable (maybe?)

4. 4 Status as of Jan. 26, 2007 TOP MIDBOT There are problems in 25 GEMs (out of 72): 16 top 5 middle 4 bottom Top GEMs… are Au (not Cu) thin (~300nm) CsI layer only GEM truly exposed to HBD volume only GEM touching the mesh’s frame ???

5. T MB 5 Examples of Various GEM Behavior 3 draw low current (410, 510, 777nA) at ~500V reflecting a very high GEM impedance (0.6 – 1.3 G  ). 9 draw high current (ranging from 3 – 15  A at about ~500V) reflecting a GEM impedance of 16 – 140M . 10 have a dead (or almost dead) short and the 10M  has been replaced by a 20 . 4 seem to have multi-strip problems and the 10M  has been removed. 47 draw < 1nA on the way up to 520V. T M B T M B T M B

6. 6 Summary 25 of 72 GEMs have troubles of some kind most (16) are top GEMs Uniform distribution of problems is scary… GEMs showing >20M  could still be more than 1 strip! 5 of 24 working modules (drawing appropriate current) 2 of these have “dead 20M  ” shorts (resistors replaced) Tentative plan for the run: frequent MIP peak scans (calibrations) swap out resistors (as needed) every access (every 2 weeks?).

7. EN012 EN0EN1EN2 TOP MID BOT

8. EN345 EN3EN4EN5 TOP MID BOT

9. ES012 ES0ES1ES2 TOP MID BOT

10. EN345 ES3ES4ES5 TOP MID BOT

11. WN012 WN0WN1WN2 TOP MID BOT

12. WN345 WN3WN4WN5 TOP MID BOT

13. WS012 WS0WS1WS2 TOP MID BOT

14. WS345 WS3WS4WS5 TOP MID BOT

15. TOP MIDBOT TOP MIDBOT TOP MIDBOT TOP MIDBOT 3 draw low current (410, 510, 777nA) at ~500V reflecting a very high GEM impedance (0.6 – 1.3 G  ). 9 draw high current (ranging from 3 – 15  A at about ~500V) reflecting a GEM impedance of 16 – 140M . 10 have a dead (or almost dead) short and the 10M  has been replaced by a 20 . 4 seem to have multi-strip problems and the 10M  has been removed.