Difference between revisions of "Minutes-6-30-2011"
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- Lubomir on second cell HV tests: the cell is assembled as a package, now with lexan sheet on the top. The gas is runinng since Tuesday evening and since Wednesday we are conditioning the chamber. Today we are at 1800V/-500V with a current of 120-130nA for the whole chamber, which is at least 10 times smaller than the first cell. So, most likely the HV problems we had with the first cell are due to the ultrasonic cleaning in water (nobody was surprised). | - Lubomir on second cell HV tests: the cell is assembled as a package, now with lexan sheet on the top. The gas is runinng since Tuesday evening and since Wednesday we are conditioning the chamber. Today we are at 1800V/-500V with a current of 120-130nA for the whole chamber, which is at least 10 times smaller than the first cell. So, most likely the HV problems we had with the first cell are due to the ultrasonic cleaning in water (nobody was surprised). | ||
| − | - Thanks to Bert Manzlak and RadCon people there's a signficant progress with the source usage at Blue Crab. Keth Welch proposed using 25 micro-Curie 55Fe source which is bellow all regulation limits, but according to JLab rules they will most likely require creating RCA at Blue Crab and some additional restriction. Yesterday Bert and | + | - Thanks to Bert Manzlak and RadCon people there's a signficant progress with the source usage at Blue Crab. Keth Welch proposed using 25 micro-Curie 55Fe source which is bellow all regulation limits, but according to JLab rules they will most likely require creating RCA at Blue Crab and some additional restriction. Yesterday Bert and Vashek Vylet (RadCon) were at Blue Crab and didn't see any problems for having a source there. Now it's up to Rusty Sprouse to decide and see if there's something in the lease explicitly saying that we can't have a source there. |
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== Engineering == | == Engineering == | ||
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- Bill: we have most of the tooling needed for the wire deadening but have to know the radii of the dead areas. Lubomir: originally it was decided to be able to register pions with 1GeV at 1deg which requires upper limits: 2.3cm 3.2cm 3.9 4.6cm (package#1-#4). Alex simulated the rates (doc linked above) and requiring to have at most 130kHz/strip gives lower limits: 2.9, 3.0, 3.0, 3.5cm. There's a conflict for the first package but it can be 2.9cm without affecting the acceptance noticeably resulting in: 2.9, 3.2, 3.9, 4.6cm. Finally, to be able to interchange modules we decided to have 3.0cm, 3.0cm, 3.9cm, 3.9cm radii of the dead areas. | - Bill: we have most of the tooling needed for the wire deadening but have to know the radii of the dead areas. Lubomir: originally it was decided to be able to register pions with 1GeV at 1deg which requires upper limits: 2.3cm 3.2cm 3.9 4.6cm (package#1-#4). Alex simulated the rates (doc linked above) and requiring to have at most 130kHz/strip gives lower limits: 2.9, 3.0, 3.0, 3.5cm. There's a conflict for the first package but it can be 2.9cm without affecting the acceptance noticeably resulting in: 2.9, 3.2, 3.9, 4.6cm. Finally, to be able to interchange modules we decided to have 3.0cm, 3.0cm, 3.9cm, 3.9cm radii of the dead areas. | ||
Revision as of 17:25, 30 June 2011
June 30, 2011 FDC meeting
Contents
Agenda
- Production (Dave)
- Status Construction Tracking
- Second cell HV tests
- Radioactive source usage at Blue Crab
- Other
- Engineering (Bill)
- Package flatness measurements
- FDC cabling
- Other: gusset rings, lifting frame
- Electronics update (Fernando, Chris)
- Chamber testing at EEL126 (Beni, Lubomir)
- First cell status top/bottom asymmetry
- Future plans
- Other
Minutes
Participants: Eugene, Bill, Dave, Chris, Mark, Roger, Simon, Beni, and Lubomir.
Production
- Dave (see the Construction Tracking link above): cell#3: cathode type-2 needs three rigid-flexes (they were glued but Casey found they had solder bridges on the connectors), cathode type-1: the rigid-flexes to be glued. Since Monday we stopped working on the wire frame that was strung, due to possible tension problems discussed later. cell#4: first cathode tensioned, gluing foils for the second one. In addition techs are laminating wire frames, 6 ready so far. Beni asked if we cover the wires while soldering; not yet but we have the cover ready and will try it for the next wire plane. So far we have seen one solder ball on the wires, and Casey removed it.
- Lubomir on second cell HV tests: the cell is assembled as a package, now with lexan sheet on the top. The gas is runinng since Tuesday evening and since Wednesday we are conditioning the chamber. Today we are at 1800V/-500V with a current of 120-130nA for the whole chamber, which is at least 10 times smaller than the first cell. So, most likely the HV problems we had with the first cell are due to the ultrasonic cleaning in water (nobody was surprised).
- Thanks to Bert Manzlak and RadCon people there's a signficant progress with the source usage at Blue Crab. Keth Welch proposed using 25 micro-Curie 55Fe source which is bellow all regulation limits, but according to JLab rules they will most likely require creating RCA at Blue Crab and some additional restriction. Yesterday Bert and Vashek Vylet (RadCon) were at Blue Crab and didn't see any problems for having a source there. Now it's up to Rusty Sprouse to decide and see if there's something in the lease explicitly saying that we can't have a source there.
