1. 1 Sasha Milov HBD meeting Oct 24, 2006 LAMP test @ SUNYSB Craig, Matt & Sasha Oct 24, 2006

2. 2 Sasha Milov HBD meeting Oct 24, 2006Set-up HV in To 1MOhm scope via coax-cable (cable has to be fixed) 24V V ref 2-7V Trigger Gas in HBD

3. 3 Sasha Milov HBD meeting Oct 24, 2006  Parameters, which do not matter: PS voltage within a Volt Trigger voltage within 2-5 Volts Trigger frequency within 5-50 Hz Trigger duration from us to ms Time after Mesh  GEM voltage is on  Parameters which do matter: Lamp reference voltage Transparent gas flow in the lamp housing Cable to the scope (1MOhm input) Mesh  GEM Voltage Time after lamp turn on if less then 10min Lamp orientation on the HBD  Parameters which might still matter Room temperature Different gas in the lamp housing What did we looked at.

4. 4 Sasha Milov HBD meeting Oct 24, 2006 Sets of measurements.  Two sets on 17 & 18 In each one can look at: Bottom vs Top North vs South Sector by sector are just geometry. fishy…

5. 5 Sasha Milov HBD meeting Oct 24, 2006 As in PHENIX: Red: SouthBlue: North Circle: Oct. 17Square: Oct. 18 Open: at topClosed: at the bottom Counting sector from lamp Shape is just an amount of light received by a sector. Not a bad reproducibility. Two fishy measurements are perhaps a human factor Sector by sector

6. 6 Sasha Milov HBD meeting Oct 24, 2006 Looking at the ratios Same results 1 day apart: 21% wide all points together 4.6% wide if 3 faulty measurements are neglected. Similar results in neighboring sectors: Circle: Oct. 17Square: Oct. 18 Open: at topClosed: at the bottom Simplest explanation: lamp orientation matters.

7. 7 Sasha Milov HBD meeting Oct 24, 2006  Do test in situ is not going to be easy: Probably only one lamp position (bottom) Might be not trivial to hook-up jumpers and cables on top use man-lift? Needs to be done a.s.a.p. and then before and after gas switch Monday was survey day. Same cable, PS, etc… not a problem. To do.