Pre-experiment Weekly Meetings Meetings

AGENDA

Presenter	06/28/2022, 10:30Am ET
Nathaly Santiesteban	[[ https://hallcweb.jlab.org/wiki/images/8/8c/June28_2022.pdf |Summary of the discussion with the theorist Jerry Miller and Wim Cosyn. ]] Higher order effects b3,b4 will have a contribution in the extraction of b1 and also in the Azz measurement. Therefore, the direction of the magnetic field may reduce those contributions. Currently, there are proposed two configurations: i) longitudinal with the electron beam (as it is in the proposal) and ii) along the q-vector. Wim will estimate the impact of having one with respect to the other to have the best configuration to be used in the experiment. However, this may be limited for the chicane and the beamline at Hall C. In which case, we need to run parallel and estimate the uncertainties accordingly.
Minutes:	Nathaly: Dave Gaskell was contacted and he along with Jim Benesh will work in finding the limitations of the chicane and beam lime. Nathaly: Dave Mack was contacted and he will work in an estimate of what is available in the lab and a timeline for the Faraday cup and lumi monitors. Dustin: We need to understand and define the helicity states we are going to use in the experiment. Therefore, if we need 2 different cells what is the configuration we are going to use? Ellie: Oscar and Ellie study the symmetry and effects of the helicity state back when the proposal was made. They concluded we needed primarily vector enhanced vs unpolarized. But, this may need to be evaluated given the effects of the higher twist b3,b4, which may imply a different orientation of the magnetic field. Dustin: In terms of enhancement it will be easier to have two cells vector polarized with zero enhancement and a mix with tensor enhancement,because of the continuous electron beam. Dustin: The backup in case we have some issues measuring the polarization could be to measure elastic data all the time. Ellie clarified that in Azz we could get elastic data constantly and we would need to evaluate for b1 what impact will have to the statistics to take elastic data. Dustin: The lineshape analysis used in the experiment will be based in two principles: i) the amount of depleting power in the hole burning needs to be 2 ices as deep in order to get the excitement, and ii) in the region that we are hole burning the spin temperature remains the same (equilibrium). The equations to understand his work are 18-30-38 from the last version of the paper Dustin sent. The word equilibrium is confusing and the best way to explain it needs to be found. Dustin: He does not access the data from the papers right now, but he will send the group a set of presentations where he went through the details of the lineshape analysis that we can use to better understand his method. Ellie recommended to look into the slides of the Hall A & C collaboration meeting, where she explain the 2 factor of the enhancement. Dustin: From following the Hall B experiment, it could be possible to use shim coils to enhance or increase the homogeneity of the field and increase the Tensor polarization. This idea could be tested in the following years before the experiment. It will be good to have a slide or two with this kind of improvements to the Tensor polarization. Dustin: We could work in a collaboration beyond be and Azz with tensor interest. In order to work in the polarization techniques along with the experiments that could be proposed. To-do: (Ellie?) Plan if we could take elastic data (T20) constantly in b1 and Azz to verify the tensor polarization on a run-by-run basis. What impact would it have for the statistics of the experiment? And what configuration would that be? Dustin will send the presentations on lineshape analysis. Ellie will put together a plan to find the best helicity states to run the experiment. Dustin will start working on the slides for the review, and he will share with us the slides to find the best way to explain the principles and the lineshape analysis that will be done in the experiment. Allison will estimate the distance between the two cells for the experiment.
Attendees:	Dustin Keller, Karl Slifer, Elena Long, Allison Zec, David Ruth and Nathaly Santiesteban

Presenter	06/21/2022, 9:30Am ET
Minutes:	Updates from Dustin: Chris has contacted him and he has informed that he will create a committee to review our experiment and he will be the chair. In order to prepare for this review he suggested cleaning the language and being clear in the terms and descriptions of the configurations used for the experiment. We will use the figures that explain better the best figure of merit. Since Nathaly spoke with Chris the previous week getting some feedback from the questions we may encounter, she suggested a meeting to discuss those list summarized in the overleaf document. Steve Wood contribution: We need to prepare to support how we will control better than 1% all the systematics. Things mentioned in Karl's talk are good at mitigating some of them, but possibly not all of them. or conditional removal, don't need to have all issues removed already but do need to make sure we have a plan of how we're going to address it. Want to show that amount of effort going into systematics is going to be on-par with amount of effort going into the target Likely to be overlap between PAC40 (b1) ITAC and the conditional removal committee Steve thinks that swapping the two target cells will work for addressing most, but not necessarily all, of the systematic drifts Though PAC focused on the target polarization, the review committee may bring up additional aspects as well. An example of this happened to TDIS, where an issue was brought up in the 'conditionals removing' review even though it wasn't directly a PAC condition For ERR, need a well-defined scope of what needs to be built and done to be able to do it Ft Update from Allison: Still has a discrepancy in the cross-section she's working with, coming off by about a factor of ten Will work with Ellie & Nathaly later this week to try to figure it out Update from Nathaly: Will talk with Dave Benisch about beamline, and other folks at Jlab (including Dave Gaskell) Tighter schedule than normal this week, will be back at UNH next week Update from Ellie: Will work on setting up meeting with us & theorists, particularly Wim & Gerry and possibly Misak, to discuss their thoughts on target field orientation
Attendees:	Dustin Keller, Stephen Wood, Elena Long, Allison Zec, Narbe Kalantarians and Nathaly Santiesteban

Presenter	06/14/2022 9:30 AM ET
Allison Zec	(A. Zec) Cross Section Calculation Slides
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

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