Pre-experiment Weekly Meetings Meetings

AGENDA

Presenter	06/14/2022, 9:30Am ET
Minutes:	Allison: working on the cross section calculation. She concluded we need a different simulation framework than that provided by Jixie. Pivoted to SimC, which is not geant based. She needed to provide her own xs to put in. For now, working with just Deuterium, but understands that we will eventually need to include unpolarized dilution (nitrogen, helium,....) Xemc for deuterium xs: which is a C++ wrapper for the Bosted code She looked at the kinematics in the b1 PAC40 proposal, although she used the P0 values for E0. XS looks reasonable, but a rough factor of 10 between her results and previous results from Ellie. First step is to rerun at the correct E0, then see if order of magnitude difference remains.
Attendees:	Elena Long, Allison Zec, and Narbe K., Karl Slifer,
Presentations	A. Zec Slides

Presenter	06/07/2022, 9:30Am ET
Minutes:	Dave Mack: We will need to build a faraday cup and invent a 10^-4 level luminosity monitor; perhaps a large angle muon telescope behind a concrete wall. There will need to be geant simulations. We have to build a low power (5 kW?) faraday cup. The positron runs will need a 50 kW cup and Dave has a 10 kW cup in storage from DESY. We will need to get the general specs (80-120nA usually with 200 mA occaissionaly) to the engineers and designers. It will be installed downstream. Depending on specs it could be a defacto beam dump or might be on a little elevator to remove from the beam. This has all been done before, atleast at the 3 kW level in hall, so should not be a huge problem. has been going thru the old docs. Primary concern of the conditional review is tensor polarization. Just need to show you have a technical solution for polarization. Prepare a presentation, worth mentioning low power faraday is needed since existing monitors will drift by atleas 0.1% over 8 hrs. We can mention that Dave is the contact on this effort. Not sure if we will build new or use an old DESY cup. The lumi's will be trickier and details will be needed for ERR, but not conditional review. The existing BCMs will not work to 0.1% over 8 hrs. But this conditional review "is not an ERR". For the eventual ERR, JLab will want the cost of the experiment to be well defined. Next 1-2 years will be NPS followed by LAD. ERR is usually needed before getting on the schedule officially. Nathaly S: One possibility is when Moller runs (in 3 years?) since they need high current and we are low current. Dave: Moller is huge endeavor and may experience delays. They will also require 100% longitudinal polarization and typical running is limited to polarized beam to 2 halls. (Not clear that this is any problem for us) Dave M: suggest to contact Jay B for the status of chicane. Dave Gaskell is beamline owner. David Flay may also be involved. issue of beads settling over time. Might not be a problem if we wait to settle or actively "settle them". Chris suggests disks. Lumi needed to monitor these types of changes. KS: we are also considering to address this by using shorter polarization cycles than 8 hours or two in-line target cells. Each brings unique challenges. z-target resolution: y-target resolution is crappy 1-2 mm. Lorentzian with long tails. z-targ then depends on angle. Dave will look at the error propagation. 2 targets will have 1% luminosity difference. He has a difficult time getting around the slow drifts. Thought about maybe monitoring a g1-type asymmetry but it is convoluted with the tensor asymm. This experiment was difficult when we proposed it, but is fairly typical for positron experiments and JLab will definitely need a faraday cup for those runs. KS : we received two invitations to the Hall A/C meeting; one on the experiment status and one on target. Experiment talk should be a rapid overview with discussion of recent progress. Target talk should highlight the overall good progress in made by Dustin/UVa, and also Ellie/UNH independent lineshape modeling progress.
Attendees:	Dave Mack, Karl Slifer, Elena Long, Allison Zec, and Nathaly Santiesteban

Presenter	05/10/2022, 9:30Am ET
Minutes:	The PAC has asked for a wiki page where we will organize the material that probes if the conditional is fulfilled. Therefore, we opened the wiki page here: https://hallcweb.jlab.org/wiki/index.php/2022_JLAB_REVIEW It will focus in two aspects: i) the tensor polarization that will be achieved under beam conditions is 30% and ii) how the polarization will be measured. The documents supporting the background and how the experiment will address the conditional will be posted there. Nathaly will organize the wiki page. One of the questions that came up in the meeting with Chris: what is needed to optimize the polarization measurements from now to when the experiment runs? Dustin will make a slide summarizing the details of: i) List of needed equipment, ii) optimization work and ii) man power. Basically, the systems need to alternate and attenuate between hole burning and phase modulation (between absorption and dispersion). There was some discussion about the new technote from Dustin about deuteron lineshape analysis. Ellie presented some questions about the population plots in the technote, especially related with the eta and phi terms. Dustin and Ellie will take this issue offline. Next meeting will be on Friday May 20 at 10 am.
Attendees:	Dustin Keller, Karl Slifer, Elena Long, Allison Zec, Narbe Kalantarians and Nathaly Santiesteban

Presenter	05/10/2022, 9:30Am ET
Minutes:	The simulation used by Narbe was SIMC. He had an older version of the Fortran code and the input files specified the packing fraction, materal, thickness, among others. The cross section weighting was probably done with F1F209. The simulation lives in UVa and we will try to get access in the following week. The email to the PAC (Bob) was send, there is no response yet.
Attendees:	Karl Slifer, Elena Long, Allison Zec, Narbe Kalantarians and Nathaly Santiesteban

Presenter	05/03/2022, 9:30Am ET
Minutes:	Questions were raised about the best simulation package to prepare for the experiment. Right now, Allison is working in the Geant4 package, but it does not have the Hall C spectrometers. However, it has the structure of the g2p target. It seems that implement the Hall C spectrometers is going to be difficult. To start addressing the best simulation package, we will invite N. Kalantarians for our next meeting. Since he has previous experience in some studies of this kind https://www.jlab.org/conferences/tensor2014/wed-pm/rondon.pdf New weekly meeting will be every Thursday at 9:30 am
Attendees:	Karl Slifer, Elena Long, Allison Zec and Nathaly Santiesteban

Presenter	04/27/2022, 10:30Am ET
Allison Zec	Geant4 Simulation Update
Minutes:	Meetings with Chris Keith on Thursday (April 28) at 10 am EST. Allison has a working geometry of the simulation. At the moment, the g2p target is on place. The spectrometer in place is the HMOS and there is some access to virtual detectors. The implementation of the tensor target, along with the geometry and the full hall C spectrometers have to be done. Dustin will like some feedback in the most recent paper.
Attendees:	Dustin Keller, Karl Slifer, Elena Long, Allison Zec and Nathaly Santiesteban