Difference between revisions of "Run1 - January 2015"

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= Run 1 Journal =
+
;[[CEBAF_MeV_Mott_Polarimeter]]
Shift leaders should make a MOTTLOG Shift Summary and link to it below.  Important READ ALL comments should be included below too...
 
  
==Shift Summaries ==
+
Mott Run 1 was performed January 13-19 with physics energy KE=5.0 MeV
Blank Template - [[media:MottRun1Database.ods]]
 
  
;Wednesday, Jan 14
+
== [[Mott Run 1 Journal]] - Our online summary of the experiment with many useful links ==
*'''[https://logbooks.jlab.org/entry/3317067 DAY]'''
 
*'''[https://logbooks.jlab.org/entry/3317139 SWING]'''
 
;Thursday, Jan 15
 
*'''[https://logbooks.jlab.org/entry/3317273 SWING]'''
 
;Friday, Jan 16
 
*'''[https://logbooks.jlab.org/entry/3317419 DAY]'''
 
*'''[https://logbooks.jlab.org/entry/3317433 SWING]'''
 
*'''[[Media:Swing16Jan15_RunLog.ods]]
 
*'''Dan created a new Mott [https://logbooks.jlab.org/entry/3317436 control screen (from command line for now)]'''
 
;Saturday, Jan 17
 
*'''[https://logbooks.jlab.org/entry/3317522 OWL]'''
 
*'''[https://logbooks.jlab.org/entry/3317726 DAY]'''
 
*'''[[Media:MottRun1Database_day17Jan15.ods]]'''
 
*'''[http://www.example.com SWING]'''
 
*'''[[Media:MottRun1Database_swing17Jan15.ods]]'''
 
;Sunday, Jan 18
 
;Monday, Jan 19
 
  
=Experiment Goals and Plans=
+
== [[Mott Run1 Target Thickness Study]] ==
 +
* elastic rates summary tables from January and May [[media:rates_summarytable.ods]]
  
Tasks which have been studied or completed are shown below in '''bold face'''.
+
== Run1 January Analysis Documents ==
 +
* element locations [[media:Run1_Beamlines.pdf]]
 +
* MBH3D00H/V are in reality MAD3D00H/V and use MAD field maps [[media:MAD_FMAP.pdf]]
 +
* chronology in different formats [[media:run1summary.txt]], [[media:run1summary.docx]], [[media:run1summary.pdf]]
 +
* on-line summary spreadsheets [[media:run1database.ods]], [[media:run1database.xlsx]]
  
== Prep Work (through Tuesday Jan 13) ==
+
== Matt's Campaign Strategy Notes from 5/1/2015 meeting ==
#'''Make a photocathode – SL5247-1 [https://logbooks.jlab.org/entry/3316714 made] about ~one week ago; QE [https://logbooks.jlab.org/entry/3317042 low] at low bias but ~1.8% at 130kV'''
 
#'''Test IHA2D00 – the Aurora card was [https://logbooks.jlab.org/entry/3316983 replaced] to fix POT sampling and CAMAC wiring fixed for gain'''
 
#'''Hi-Pot IP – 3D01 hi-potted, but still bad so [https://logbooks.jlab.org/entry/3316954 moved] to Dig#11 holding supply and 3D00 on Dig#12 monitors beam line only'''
 
#'''CHL 2K cooldown – 1/13 successful cool down completed'''
 
#'''Install laser – first [https://logbooks.jlab.org/entry/3317043 beam test] of Hall C laser with division by two rep rate'''
 
#'''Test laser RF trigger – Riad is using Hall A laser as reference; appears to be 499/2^N'''
 
#'''Verify beam line layout – completed'''
 
#'''Build elegant deck – completed and stored at ~grames/elegant/MOTT/'''
 
#'''Build qsUtility config file – completed, see below...'''
 
  
== Injector Setup and Mott Checkout (Wed Jan 14 - Fri Jan 16) ==
 
#'''Restore beam to FC2 @ 6.3 MeV/c - 1/14 task was completed and summarized in [https://logbooks.jlab.org/entry/3317071 link title]'''
 
#'''Mott test: DAQ FADC/TDC synchronization and event separation with 62MHz; there is a TDC issue that prevents 62MHz so we use 31MHz with 31MHz trigger'''
 
#'''Electron [https://logbooks.jlab.org/entry/3317058 bunchlength] and transmission from 0-10 uA'''
 
#'''Tested harp IHA2D00 and it [https://logbooks.jlab.org/entry/3317133 works]'''
 
#'''Scale cryounit for p=5.487 MeV/c and minimize energy spread - 1/14 see entry for [https://logbooks.jlab.org/entry/3317094 link initial setup]'''
 
#'''[https://logbooks.jlab.org/entry/3317138 Tried] bunchlength script - didn't coverge, but looks like with more time can work'''
 
#'''Calibrate BCM to FC2; [[Media:BCM-calibration-slope16jan15.ods]]'''
 
#'''John [https://logbooks.jlab.org/entry/3317175 improved] the laser polarization and measured the Hall C laser [https://logbooks.jlab.org/entry/3317183 spot size]'''
 
  
== Mott Setup and Systematics Testing (Sat Jan 17) ==
+
'''''Measure Asymmetry vs Target Thickness'''''
#'''Setup good orbit to Mott [https://logbooks.jlab.org/entry/3317368 here]'''
+
* Take data at 5 MeV/c  (done)
#'''Set PMT HV [https://logbooks.jlab.org/entry/3317401 here]'''
+
* Measure the thickness of companion foils, our x-axis error bar (Mamun finished with measurements, Marcy completing analysis)
#'''Set PMT energy thresholds are [https://logbooks.jlab.org/entry/3317405 here]'''
+
* Assess mott spectra and assign sensible cuts, energy and time  (Joe working on this now)
#'''Finally we setup the polarization horizontally; [https://logbooks.jlab.org/entry/3317347 initial "rough in"] and the [https://logbooks.jlab.org/entry/3317584 final] here'''
+
* Using the cut guidance from above, analyze our runs and create the Asym vs Target Thickness plot, with statistical error bars in Y and error bars in foil thickness from step 1b  (Daniel to work on this soon, with Joe's help. Batch runs favored)
#'''[https://logbooks.jlab.org/entry/3317490 Calibrate] PITA vs IHWP IN/OUT'''
 
#'''Finalize orbit w/ instrumental asymmetry, TOF and spectra'''
 
#'''Adjust target offsets per vertical instrumental asymmetry [https://logbooks.jlab.org/entry/3317427 measured], [https://logbooks.jlab.org/entry/3317426 analyzed], and [https://logbooks.jlab.org/entry/3317428 corrected] with new offsets [[media:New_Ladder_Position_Swing16jan15.ods]] '''
 
#'''[https://logbooks.jlab.org/entry/3317599 Measure] dump rate fraction to determine run times, [[Media:Dump_vs_Elastic.ods]]'''
 
#'''Measure asymmetry vs. dead-time and beam current [[Media:Deadtime_spreadsheet.ods]]'''
 
#Measure asymmetry vs. spot size (included emittance measurement and Elegant optimization)
 
#Measure asymmetry vs. energy spread (includes harp scans, see e.g. [https://logbooks.jlab.org/entry/3317265 here]'''
 
#Precisely measure beam momentum (includes BPM quad centering)
 
#Measure asymmetry stability vs. time (by virture of the 1um Au tests interleaved w/ target foil extrapolation)
 
  
== Target Foil Extrapolation (Sat Jan 17 - Mon Jan 19) ==
 
#'''The list of targets and some description is describe in this [https://logbooks.jlab.org/entry/3317676 entry]'''
 
#We are planning to interleave two 1um ~1uA (~15% dead) runs of IN/OUT between each foil
 
#Test each new target foil to determine if energy spectra are good/bad.  If not acceptable or don't want to try, move on to next one, make log entry...
 
  
=Procedures=
+
'''''How to assign Systematic Error?'''''
 +
* Review our results, hopefully we find Asymmetry was relatively insensitive to the things we varied.  Still a bit vague to me, how to assign a systematic error.  (Daniel will analyze and summarize results from systematic studies, group should brainstorm to assign the value)
  
== How to contact people ==
 
;Joe's cell : 757-344-0188
 
  
== How to reach the Mott logbook ==
+
'''''Extrapolate asymmetry to Zero Thickness, determine single atom Mott Asymmetry'''''
;Mott logbook is [https://logbooks.jlab.org/book/mottlog here]
+
* What is a sensible functional form to fit data?  GEANT model will tell us this.  (Marty working on this now). Assign a systematic error to the extrapolation.
 +
* Use our fit result of Mott Asymmetry at zero thickness and Xavier’s theoretical prediction of Sherman function to calculate beam polarization, what is the error on the theoretical prediction? (Charlie working on this now, Joe mentions this might already be on wiki)
  
== How to know who's on shift ==
 
[[File:140112_shifts.png|thumb|center|300px]]
 
  
== How to be a shift worker ==
+
'''''Assign a polarization value to our beam: Pol = P ± Stat ± Syst ± Theory'''''
; Beam Driver = Shift Leader
+
* Joe makes the point, Asym vs Thickness at different energies can provide more confidence (in Syst uncertainty) that our functional form fit is credible.
#Control delivered beam, especially adjusting PITA with IHWP=IN/OUT
+
* A good fit obtained for all tested beam energies, with each fit indicating the same beam polarization, like Michael did, would be a powerful validation of our "model" (could take more data in summer, Riad cautions, better to assess Run1 first)
#Make sure FSD (BCM, Target) protection is used
 
#Monitor beam loss and vacuum levels
 
#Save and document settings
 
#Write shift summary in logbook
 
; DAQ Driver
 
#Configure/Start/Stop DAQ
 
#Monitor event rates and maintain dead time <5%
 
#Coordinate run start/stop
 
#COPY run information into standard excel sheet
 
; Analysis Driver
 
#Decode, analyze and inspect runs
 
#COPY run information into standard excel sheet
 
#Determine number of events needed for IHWP=IN and OUT
 
  
== How to measure emittance ==
+
''Riad favors asymmetry measurements using low-Z target material, as providing more impact for Theory''
; Beam Setup
 
#We measure the beam emittance and Twiss at entrance of MQJ0L02 by varying MQJ0L02 and observing response on harp IHA0L03
 
#To simplify matters we turn off the intervening quadrupoles (MQJ0L02A = MQJ0L03A =MQJ0L03 = 0)
 
#Obviously, make sure beam can transports from MQJ0L02 to IHA0L03 w/ those quads off (use BPM's and viewers)
 
#The configuration changes MQJ0L02 B for 21 K1 values (-3.0, -3.2, … , -5.8, -6.0); this takes ~45 minutes, so a smaller data set could be used too
 
; qsUtility
 
#We use program named qsUtility to automatically to make the measurements and analyze the data
 
#The measurement configuration file is here and can also be used as a template /cs/prohome/apps/q/qsUtility/pro/fileio/config/IHA0L03_jmg1.xml
 
#qsUtility is documented [http://opweb.acc.jlab.org/CSUEDocs/q/qsUtility/pro/doc/dataCollector_user_guide/dataCollector_user_guide.html here]
 
; qsUtility assumes v=c
 
#One must scale the Energy [MeV] entry box as the tool uses this formula B'L [G] = K1[1/m^2] * L[m] * E[MeV] * 10/0.2998
 
 
 
== How to measure momentum ==
 
; Note quads used for centering
 
#MQJ0L02 = IPM0L02
 
#MQJ0L03 = IPM0L03
 
#MQD5D00 = IPM5D00
 
#MQD5D01 = IPM5D01
 
; Center quads
 
#Mike Spata suggests standard dithering, as we do for solenoids
 
#When complete update the BPM .SOF field and log result
 
; Momentum measurement
 
#Excite minimum number of correctors and record values
 
#Set or measure BL using calculation on MDL0L02 control screen
 
#Make note of BL for zeroing IPM0L02-IPM0L03 and IPM5D00-IPM5D01 with (intervening quads OFF, correctors OFF or recorded)
 
#Calculate momentum from KE as p = sqrt [T*(2m+T)], so T = 5.0 MeV =>  p 5.487 MeV/c
 
#Calculate fraction KE spread as dT/T = (T+2m)/(T+m) * dp/p, so dT/T=1.09 * dp/p @ T=5.0
 
 
 
== How to use Elegant files ==
 
; Elegant files for 2D, 3D, 5D, 0L regions
 
# locate /grames/elegant/MOTT/mott3/
 
# set mott3.ele beamline to be either 0L, 2D, 3D, 5D
 
# set mott3.ele emittance, Twiss and momentum spread
 
; To run
 
# Copy files to local area
 
# Interactively: Start IEE from terminal and then load elegant file: /grames/elegant/MOTT/mott3/mott3.ele
 
# Command: From terminal execute elegant mott3.ele
 

Latest revision as of 21:00, 13 August 2015

CEBAF_MeV_Mott_Polarimeter

Mott Run 1 was performed January 13-19 with physics energy KE=5.0 MeV

Mott Run 1 Journal - Our online summary of the experiment with many useful links

Mott Run1 Target Thickness Study

Run1 January Analysis Documents

Matt's Campaign Strategy Notes from 5/1/2015 meeting

Measure Asymmetry vs Target Thickness

  • Take data at 5 MeV/c (done)
  • Measure the thickness of companion foils, our x-axis error bar (Mamun finished with measurements, Marcy completing analysis)
  • Assess mott spectra and assign sensible cuts, energy and time (Joe working on this now)
  • Using the cut guidance from above, analyze our runs and create the Asym vs Target Thickness plot, with statistical error bars in Y and error bars in foil thickness from step 1b (Daniel to work on this soon, with Joe's help. Batch runs favored)


How to assign Systematic Error?

  • Review our results, hopefully we find Asymmetry was relatively insensitive to the things we varied. Still a bit vague to me, how to assign a systematic error. (Daniel will analyze and summarize results from systematic studies, group should brainstorm to assign the value)


Extrapolate asymmetry to Zero Thickness, determine single atom Mott Asymmetry

  • What is a sensible functional form to fit data? GEANT model will tell us this. (Marty working on this now). Assign a systematic error to the extrapolation.
  • Use our fit result of Mott Asymmetry at zero thickness and Xavier’s theoretical prediction of Sherman function to calculate beam polarization, what is the error on the theoretical prediction? (Charlie working on this now, Joe mentions this might already be on wiki)


Assign a polarization value to our beam: Pol = P ± Stat ± Syst ± Theory

  • Joe makes the point, Asym vs Thickness at different energies can provide more confidence (in Syst uncertainty) that our functional form fit is credible.
  • A good fit obtained for all tested beam energies, with each fit indicating the same beam polarization, like Michael did, would be a powerful validation of our "model" (could take more data in summer, Riad cautions, better to assess Run1 first)

Riad favors asymmetry measurements using low-Z target material, as providing more impact for Theory