View source for Mott Run 1 Journal

;[[CEBAF_MeV_Mott_Polarimeter]]

==Shift Summaries == 
Blank Template - [[media:MottRun1Database.ods]]

;Wednesday, Jan 14
*'''[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
*'''[https://logbooks.jlab.org/entry/3317827 OWL]'''
*'''[https://logbooks.jlab.org/entry/3317923 DAY]'''
*'''[[Media:MottRun1Database_owl18Jan15.ods]]'''
*'''[[Media:thickness_runs.ods]]
*'''[[Media:Day_shift_database.ods]]
*'''[https://logbooks.jlab.org/entry/3317955 SWING]'''
*'''[[Media:Swing_shift_database.ods]]
;Monday, Jan 19
*'''[https://logbooks.jlab.org/entry/3318062 OWL]'''
*'''[https://logbooks.jlab.org/entry/3318217 DAY]'''
*'''[[Media:Day_shift_Monday_database.ods]]'''
*'''[https://logbooks.jlab.org/entry/3318216 SWING]'''
*'''[[Media:FINAL_run_database.ods]]

=Experiment Goals and Plans=

Tasks which have been studied or completed are shown below in '''bold face'''.

== Prep Work (through Tuesday Jan 13) ==
#'''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) ==
#'''Setup good orbit to Mott [https://logbooks.jlab.org/entry/3317368 here]'''
#'''Set PMT HV [https://logbooks.jlab.org/entry/3317401 here]'''
#'''Set PMT energy thresholds are [https://logbooks.jlab.org/entry/3317405 here]'''
#'''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'''
#'''[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 contact people ==
;Joe's cell : 757-344-0188
;Riad's cell : 757-254-7895

== How to reach the Mott logbook ==
;Mott logbook is [https://logbooks.jlab.org/book/mottlog here] 

== How to know who's on shift ==
[[File:140112_shifts.png|thumb|center|300px]]

== How to be a shift worker ==
; Beam Driver = Shift Leader
#Control delivered beam, especially adjusting PITA with IHWP=IN/OUT
#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 ==
; 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