Minutes of the E00-102 Planning Meeting Wednesday 010627 KF Present: MA Mattias Andersson WB William Bertozzi KF Kevin Fissum EF Ed Folts DH Doug Higinbotham WH Wendy Hinton KJ Kees de Jager JL John LeRose ML Maurizio Lucentini BR Bodo Reitz AS Arun Saha LW Larry Weinstein YX Yuan Xiao JZ Jindong Zhou o AS summarised the previous meeting. He began with an overview of the run period schedule: 04 Oct - 05 Oct: commissioning 06 Oct - 21 Oct: run 22 Oct - 25 Oct: maintenance 26 Oct - 18 Nov: run He then presented a quick overview of the kinematics. JL assured us that 4.121 GeV/c for the HRSl will be OK. Mark Stevens understands the problem that arose during the high field testing (a defective part) and is correcting it. WB questioned our understanding of the HRS2 at these excitations. LW responded that the HRSr, at roughly 1 GeV/c, is well-understood, while the HRSl will require characterization. JL said he doesn't expect much deviation from the 4 GeV/c optics. DH mentioned that Nilanga together with Haiyan's students have been fine-tuning a 4 GeV/c extended target database that should work well for us, and that he would investigate the particulars. LW pointed out that for our delta-scan, we will need a few percent above 4.121/c GeV for the HRSl. JL said no problem. o AS showed several drawings of the waterfall target and the scattering can, and how LW's design has been implemented. The entrance and exit windows are 75 um Be, and the side windows will be 75 um stainless. Because of the geometry, this will result in about 350 um of stainless for the scattered electrons to traverse. WB questioned if these exit windows are the dominant mass in the target, and LW pointed out that the ~1 gm of water is still the dominant mass. WB also questioned the anticipated resolution. AS answered that because of the similarities to the target in e89044, he estimated that we will have an Emiss resolution of about 2 MeV. o LW pointed out that the clearances for the various trajectories in his design are on the order of 2 mm. Thus, the installation and surveys of the entire target apparatus are absolutely crucial so that we don't inadvertantly clip a post. The long dimension of the can must be installed in as parallel a manner as possible w r t the beam direction (a 5 mrad kilter is the maximum tolerable). EF said this parallelism is limited by the accuracy of the surveys, 0.5 mm. The actual centering of the beam on the target will be performed by sweeping a very low current beam left/right on the installed target until the posts are clipped. AS suggested we need someone from our group to take on the task of working closely with the survey group. This task remained unassigned. o AS stated the Italian techs are hard at work in the Physics storage building 72 getting the waterfall target up and running, and introduced ML, who reported on the status of the waterfall target. All the mechanisms from the previous design have been simplified. They are currently working on the slow controls to move the target ladder up and down. This motion will be interlocked to beam off of course. The thickness of the target foils can be varied by changing the pump speed. There is a slight time-dependence in this thickness. There is room for three solid targets to be hung in the solid target ladder mounted underneath the water can. We decided we would like a well-understood BeO foil of comparable geometry-adjusted thickness (the solid targets are perpendicular to the beam) to a single water foil (~300 mg), a well-understood thin carbon foil, and perhaps a third foil of some with a hole in it so that we know when we have the beam centered in the manner we want. EF suggested buying new foils rather than recycling the ones we currently have. ML invited anyone interested to come and take a look at the target, but first call 5526 to set up an appointment. o AS stated that we are anticipating 100 uA of beam, and that there are no plans to raster. His calcs indicate the Be windows can easily handle the power deposited. EF was informed that we need the scattering chamber support posts to be out of the lab angular range between 25 deg and 100 deg on the HRSr side. o BR gave an overview of the detector stacks as we will use them. HRSl: VDC, S1, A1/S0, RICH, S2, PR HRSr: VDC, S1, S0, LGC, S2, PS, TS He pointed out that this is a rather standard configuration, that the RICH collaboration will take care of their detector, that the S0s need substantial work, and that he and Bob Michaels will take care of the trigger manipulations. AS pointed out that SOl has the highest priority, and that SOr has lower priority. WB stated that YX and JZ will take on the responsibility of delivering working SOs. EF indicated Bogdan has requested tech support for this project as well. YX, JZ, BW will get together on this subject. LW questioned whether we wanted useless cerenkov counters in the trigger since we are unable to use either A1 or LGC. o WH presented a very detailed calibration runplan which involved white spectra, focal plane efficiency tests, target boiling tests, current calibrations, and target thickness calibrations, and summed to about 30 hours realtime. DH made some suggestions to optimize the ordering, and further suggested we take the time to do a serious, high-quality current calibration at the start of the experiment. WH then presented a table of kinematics and approximate runtimes assigned to each. A discussion of \theta_pq points followed, and we decided on the following HRSr angles for the Alt portion of the experiment: \theta_pq = \pm 03.75, \pm 05.60, \pm 07.50, \pm 09.40, \pm 11.20, \pm 14.90, \pm 18.60, \pm 23.27, \pm 27.95. KF agreed to run these through MCEEP again. We decided also to find a "happy medium" HRSr excitation to sit at for the entire experiment rather than tweaking the HRSh field. DH questioned the order of the measurements and it was agreed that we would start in parallel kinematics and work our way out. WB questioned which of the "1H-tricks" we intended to employ this time. LW informed him we will rely on survey for the angular location of the spectrometers, but will determine qvec e t c using the 1H-tricks as per the previous experiment. o BR showed the experiment tasklist and we put some names to tasks. AS will take care of the COO and paperwork, and hopes that BR will act as PL. KF and LW (and anyone else who wants to help, of course!) will get together and scratch out a first-order runplan before the next meeting. Dmitri Margaziotis will take care of the shift signups, BUT we will exercise quality control (i e solicit shifts) for certain crucial time periods (like startups, e t c). KF will take care of the experiment webpage. BR reported that he had contacted the necessary people to setup the e00102 mailing lists. There will be two: e00102@jlab.org and e00102_analysis@jlab.org. o DH indicated that it would be reasonable to contribute MIT manpower to working on getting the ROOT analyser up and running for this experiment, but that we should also have ESPACE in place as our failsafe analyser. WB agreed, and committed YX and JZ to the project. BR pointed out that having an ESPACE analyser in place incurred essentially no overhead since it is a standard, working package. We decided on the parallel approach - as much ROOT as is available, with ESPACE as the failsafe. o DH pointed out that we should put high priority into getting the scripts which carve up the run summaries and place the information into a database in place *before* the experiment. He will talk to Rikki Roche about what the NDelta group did since Joe Mitchell is no longer available. o DH made a list of run coordinators which included himself, Simon Sirca, WH, and BR. There is some question as to whether or not Nilanga will be available. AS pointed out that the waterfall target is a much simpler device than cryotarget, so that it may be possible to get away with two people per shift. KJ indicated that he would prefer to see three. o finally, we discussed what physics we would like to do if more time were to come available. LW and WB agreed that our contingency plan should be to execute the experiment we proposed in its entirety - that is, first to focus on the cross section at very high pmiss, and then to step out in Emiss for several pmiss points. KF will dig out Udias' predictions for Atl for the 1s12-state for the next meeting. AS will ask Nilanga to evaluate this quantity for his data for the next meeting as well. o finally, we decided that Monday, July 9th, 14.00 will be the next meeting date. Room L207 has been booked as it is the only one available.