PolHe3 Target Coil Rotation Plan, Mar 2020
From HallCWiki
Target coil rotation planned for March 13--20
- Nominal 1-week downtime in Hall C to rotate target coils, install new cell, and transition to d2n program
Meeting on Tuesday, March 10 @ 2:30pm
- Room: CC F224/225
https://bluejeans.com/447872579 Meeting ID: 447 872 579 Ph: +1.888.240.2560 (US Toll Free) https://www.bluejeans.com/premium-numbers
Misc Questions / Comments
- Repair/Replace failed laser from Saturday [1]
- Does the nitrogen gas panel on upstream of target have enough play to rotate? (Jack, Andy?)
- Only clean the enclosure panels with isopropyl -- do not use Spray-9 (it leaves a residue that prevents the tape from sticking)
- Make sure the spectrometers can rotate
- S & A needs the SHMS to be at 30 degrees for their initial setup
- Keep the SHMS beam-left side fairly clear to allow S & A to access their floor targets
- May impact where the parasitic test stand goes
- Do we have enough interlock panel switches in case they get damaged? (Brad has emailed Mark Taylor)
- Spares switches are ordered; extra wire is in-hand (may also have a few leftover switches on-site?)
- Develop a plan with RadCon for working in around the target enclosure (contamination risks)
- Find our good label maker and pre-make labels for cables that we know we will have to disconnect (Arun, Junhao, Bill?)
- Any special pNMR, EPR commissioning plans (JP, Todd?)
- Field and compass measurement plan (Wolfgang, Murchhana)
ATLis / CLists
- Beamline window removal/installation (ATLis)
- D2N Magnet, Target and Pointings (HCList)
- RWP (David H.?)
Bullet point Plan
Very high-level outline from Bert (Most of this would start on Saturday)
- remove 6 helmholtz coil covers and 2 beampipes
- sharpie mark corrector coil location and rotations (so they go back in the same way)
- remove 4 corrector coil stands let corrector coils rest on bottom
- tape measure locate 4 new 3/8-16 tapped holes for the corrector coil stands
- check for items that will affect coil rotation
- rotate helmholtz coils ccw 45 degrees (to zero)
- survey helmholtz coils to zero degrees
- install covers and new beampipes
- check jet nozzles did not get disturbed for the beampipes
Friday, March 13
- It would be useful for Ethan, Bert, and the Techs to get in in the morning (after panels are off) and talk through the job
- Techs load up hardware for Hall in ESB in the morning
- Locate the extra beamline windows (found: in the big white box in ESB -- BDS)
- Optics table for Compass measurements
- Field measurement jig?
- Parasitic Cerenkov test hardware/stand
- Beam off at 8am
- Radcon Survey -- Move to Controlled Access
- Prep to open the Enclosure for final polarimetry measurements
- Laser controlled access
- Final measurements on target cell (EPR, etc)
- Plan for Hall to move to Restricted around 1pm
- Work through remaining DAY, SWING
- Bleed up beamlines *with N2* to allow up/downstream stubs to be removed (Gaskell, Marble)
- Clearly label all cabling/lines that will to be removed/disconnected!
- Interlock cabling, gas lines, coil power cables, target control and readback cabling, etc
- Put guards on the up/downstream window spools
- Put guards on HMS/SHMS windows
- NOTE: Be beamline windows need to be protected from air (put in Rad bag and fill with dry nitrogen?)
- NOTE: Removal may be deferred to Saturday (in which case the Hall C Techs must be able to remove both the up- and down-stream windows)
- Target Group work (with RadCon support -- RW-II environment!)
- Remove the target enclosure panels (minimum 2; perhaps all?)
- Remove target ladder/cell
- Remove reference cell
- RadCon will remove their Contamination mitigation sheet under the target ladder
Saturday, March 14
- Remove Be beamline window spools (if not done already)
- Upstream beamline must be bled up with nitrogen at this point
- NOTE: Be beamline windows need to be protected from air (put in Rad bag and fill with dry nitrogen?)
- Techs w/ Target group rotate the coils
- sharpie mark corrector coil location and rotations (so they go back in the same way)
- remove 4 corrector coil stands let corrector coils rest on bottom
- tape measure locate 4 new 3/8-16 tapped holes for the corrector coil stands (drawing linked below)
- check for items that will affect coil rotation
- rotate helmholtz coils ccw 45 degrees (to zero)
- Target work as needed/possible (Laser optics alignment checks, re-attach cabling, etc?)
Sunday, March 15
- Complete rotation, recable where possible keeping in mind that we may need adjustments with Survey support on Monday
- Install the compass measurement optics table (remove ladder to upper target platform)?
Monday, March 16
- Survey and Alignment
- Confirm target and beamline laser alignment
- Support setup for Field and Compass measurements (start in Swing?)
Tuesday--Wednesday, March 17, 18
- Reinstall beamline window spools, pump down beamlines when ready (install protective window guards)
- Possible pointing Surveys for SHMS, HMS (TBD)
- Field and Compass measurement continue as needed
- Install reference cell, leak check, etc.
- Install target cell and ladder as soon as possible
- Recommission target and start spinning up ASAP (through SWING and OWL as needed)
Thursday, March 19
- Target optimization, Float
Friday, March 20
- Deadline to start beam recovery to Hall
Drawings / Photos
- Photos of Target Setup (google drive link)
- CAD Models from Bert
- JT files
Component/Hardware Status
- Oven bottom plate (Arun/Bert)
- Follow up with Vince Pope in Machine shop (Arun)
- Will be ready on Thursday (updated)
- Kepco power supply status (Bill/Todd?)
- Status is unclear
- We need to establish what target angles will be (remotely) accessible (90, 180, -90?, 0?)
- Target cell Austin (Todd, Xiaochao)
- Only 'Reduced set' of density measurements available from UVa (issues with laser at UVa)
- Cell now at W&M, density measurements will be confirmed/refined there (as of Wed)
- Wall and window thicknesses done
- It would be best for it to arrive at JLab on March 10 (at the latest) to allow locals to mount cell in oven plate before they get involved with target work in Hall.
- Only 'Reduced set' of density measurements available from UVa (issues with laser at UVa)
- Lots of preplanning to be completed (RadCon, Techs, S&A, Target group, etc)
- Had job walkthrough meeting this (Monday) morning with the above parties -- so far, so good
- Must coordinate Tech support with the parasitic test installation plans
- RW-II training for JP, Arun, Brad, Bill
- Test is taken, awaiting the practicum (RadCon)
Items that have been declared ready by (owner)
- pNMR coil mount and wire for new cell
- on table in EEL target lab (Mingyu)
- spare convection heater strips
- on table in EEL target lab (Mingyu)
Target Field Measurements
Main page is here: Pol_He3_Field_Mapping_Data (Field and Compass data)
Field Mapping from November
- Pol_He3_Field_Mapping_Data (also updated by Jixie 2/26)
- High-level results file
- Copy also available here: https://userweb.jlab.org/~jixie/A1N/mapping
- He3_Target_Field_Mapping_Status_20200212.pdf -- Report from 2/12/2020
- File with pending questions/clarifications (Jixie working on response)
Compass Measurements
- Media:Procedure for compass measurement.pdf (Murchhana)