CALICE MAPS Meeting, RAL, 01/06/09 ================================== Present: Jamie Crooks, Paul Dauncey, Marcel Stanitzki, Jan Strube, Nigel Watson, Gary Zhang Phone: Dave Cussans, John Wilson Minutes: Paul Minutes of previous meeting: No corrections. Jamie thinks it is unlikely that the bulk pixel gain can be reduced enough to see the high Fe55 peak in the bulk pixels. The Diamond people have said that we would not be able to work there on an informal basis, but would need to apply for time like any other group. It is not clear if there is a cost for this. Nigel said that Chris Parkes has run tests there recently so Paul will contact him for some information on the practicalities. Sensor testing: Jamie showed some results on the new TPAC1.2 sensors, which arrived at RAL around 10 days ago; see slides on the usual web page. The serial numbers are quite varied because he is reusing PCBs which had TPAC1.1 sensors. Paul commented that the software uses the serial number to distinguish the TPAC versions so this will have to be changed. The "alignment" labels on slide 3, showing "laser" or "center" indicate the two positions a sensor is glued to the PCB. "Center" means the sensor is glued centrally on the PCB so using these PCBs with differing orientations in the beam test stack will still have the sensors in the same position. The "laser" position is offset so as to make sure the two test pixels are centred on the small notch in the PCB, to allow laser illumination. These should not be used in the beam test stack if it can be avoided. Jamie specifically pointed out that there is at least one effectively working hi-res sensor in his list. Paul showed some slides on trimming a TPAC1.2 sensor; see usual web page. He should cross-check the mean shift for the trim against the value for TPAC1.0; Jamie added one high-end bit and one low-end bit to the trim setting, so the range should be extended by a factor of two and the LSB effect should be a factor of two smaller. Paul should also check TPAC1.0 for the spread of the noise, as seen on slide 15. [Note added after the meeting: The TPAC1.0 trim response was shown in Paul's talk in the meeting on 04/06/08, slide 4. The linear region shows a response of ~6TU per trim unit, which is indeed double the value seen now. In fact, the whole curve including the non-linear region looks very similar, allowing for the factor of two in the trim value.] Jamie wants to set the external resistors which adjust the trim range. It was concluded that compared to the response curve shown on Paul's slide 11, then the trim range should be approximately doubled to use the full 0-63 range, and if the non-linearity can be reduced, this should also be done. It is important that a range of ~200TU for moving the pedestal should be possible. Paul will take sensor #29 to Imperial today. Jamie will mount a new sensor in the CALICEDAQ1 test stand this afternoon and Paul will repeat the trim measurements on this. After confirming it looks similar, then Jamie should adjust the resistors to optimise the trim response and Paul will check the change is as expected. Marcel has run TPAC1.2 with Fe55 and has seen hits at a basic level. He will have quantitative results soon and will distribute plots when they are available. [Note added after the meeting: Some plots have been added under this meeting on the usual web page.] Test beam: We will only find out if SPIDER will be funded long-term in Nov this year at the earliest. It may then be Apr 2010 (i.e. the start of FY10/11) before we get the funding, which would be one year later than planned. Marcel and Mike are bidding for bridging funds to keep us going until then and Marcel asked to know about anything which would need to be purchased in this FY. In principle, the TPAC1.2 tests, including the beam test, need very little new equipment. Dave suggested getting some PCI (Express?) cards, each of which would allow four USB_DAQs to connect to a single PC without a major loss of rate, but these would be only ~20 pounds each. Dave will send suggestions for such cards to Marcel and Paul; we should go ahead with buying and installing these straight away. Marcel suggested putting in around 5kpounds for consumables, but this may be hard to argue for without specific items. Marcel will start using the CAEN power supply for TPAC bench tests to check there are no complications (change of noise, etc.) when using it. As TPAC1.2 is now looking promising, Paul will contact the DESY people again to discuss dates for the beam test there. Nigel has the semi-online monitoring code, which Yoshi was working on, on the DAQ PC at Birmingham. He will contact Jan about getting this upgraded to work for the next beam test. AOB: There is an STFC/PPAP "Particle Physics Roadmap" meeting at Birmingham on July 13-15, with the "Energy Frontier" being discussed on Tue 14 Jul. This is clearly relevant to SPIDER so we should expect to be approached by a speaker (or asked to provide a speaker) and people should try to attend. Next meeting: This will be at 10am on Thu 25 Jun at RAL.