* Next meeting: Friday March 5th 4pm in "the Motel" * attendees: Rodion, Markus, Nick, Kai, Daniel, Helen, Jamie, and Philippe * Plan for next week (modulo the cryogenic problem still not resolved): -Monday: If cryogeny ready, set-up two pulses laser within the same rf-bucket and do gun-studies (Rodion+Philippe) -Tuesday: 9-Cell Transfer matrix (Philippe) -Wednesday: Beam spot measurements (Kai+Steve?) -Thursday: Morning: Plasma (Matt et al.) Afternoon: Bunch length (Daniel) Could then switch back to plasma if desired (Matt et al.) -Friday: Plasma (Matt et al.) * Last week achievements: - Monday: Safety interlock checks + work on the laser (Chuck Worrel, Jamie, Rodion) - Tuesday: Round beam studies (Kai + Steve), the studies were impacted by laser transverse spot structures - Wednesday: Morning some work on the rf (Markus) Afternoon: work on transfer matrix of the 9-cell, took a set of data to calibrate the corresctors (Philippe) - Thursday: Started working on the 9-cell T-matrix (Philippe), but then decided to let Brian do some cryogenic work to fix a problem that was impinging the 9-cell operation, the problem get worse afterward, and presently the cryogenic system is down and under repair Later in the afternoon Rodion, Philippe and Nick did some streak camera measurement of the UV laser, the pulse length was 4 +/- 1 ps (measured on a series of five shots), Rodion then work on the pulse stacker, but had problem to spatially align the four stacked pulses - Friday: Laser work (Rodion, Jamie) and work on the 9-cell cryo on going. * Discussions: - There were discussions on data storage/back-up issues triggered by Jamie request for a DVD writer and a hard drive, both for the laser roo Mac. It was agree that we need to make sure before proceeding, that the DVD can be used by other people within the group on various plateform (especially Linux). There was also question about the best way to handle the A0 data, Philippe mentioned the "a0pi project" has some space on afs maintained mentioned the "a0pi project" has some space on afs maintained by the computer division, as he requested such a space a year ago for storing images. Markus will check the DVD writted Jamie requested and is compatibility with Linux, Philippe will check/ request more space on afs. - Kai presented his thoughts on the topics of beam size measurement, there was some pationated discussion the last two Mondays video conference between PITZ and FNAL. He notably showed via a simple model that background subtraction do not alter the rms properties of the beam (by generated a beam with noise and subtracting the noise generated at another time). He will include the PITZ way of processing image in his model for further comparison. - Markus presented his latest digital camera investigation. Markus proposed to buy a SONY digital camera with high resolution. We will actually get one of this camera as a trial for a week in the next weeks. He suggested a way, with a hub to get several of this camera controled by one computer. The use of several digital camera has the advantage of adding the capability of taking pictures at different location for the same shot. This could be use to record the virtual cathode spot and simultaneously record the corresponding electron distribution observed on a viewer downstream. - Nick triggered some discussion about the laser oscillator potential upgrade. It was agree that before proceeding we need (1) to have a clear documentation of what in the present laser fails the most (2) then try to develop a possible alternative scheme. For the basic beam dynamics studies, the main shortcome, presently, is the transverse non-uniformity/structure of the laser spot on the cathode.