Difference between revisions of "Data Analysis - General Parameters"

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===gbeam===
 
===gbeam===
 
The gbeam parameter files include information related to the surveys of absolute beam position using HARP scans and the EPICS RAW BPM variables.  The naming of these parameters is self-explanatory, but the sign on many of the parameters is not straight forward because the difference in coordinate systems in the hall.  Refer to the BPM calibration procedure for specifics on this.
 
The gbeam parameter files include information related to the surveys of absolute beam position using HARP scans and the EPICS RAW BPM variables.  The naming of these parameters is self-explanatory, but the sign on many of the parameters is not straight forward because the difference in coordinate systems in the hall.  Refer to the BPM calibration procedure for specifics on this.
−
; Use the Hall C EPICS RAW BPM values in units of cm
+
;Hall C EPICS RAW BPM values in units of cm
 
:  gbeam_{x,y}
 
:  gbeam_{x,y}
 
:  gbeam_{xp,yp}
 
:  gbeam_{xp,yp}
  
−
; Add new variables for Hall C BPM A, B, and C, based on HARP calibration
+
;Hall C BPM A, B, and C, slope and offsets based on HARP scans
 
:  gbpm{x,y}{a,b,c}_slope
 
:  gbpm{x,y}{a,b,c}_slope
 
:  gbpm{x,y}{a,b,c}_off
 
:  gbpm{x,y}{a,b,c}_off
  
−
;positions of BPMs relative to target
+
;positions of BPMs relative to target determined from Survey and Alignment
 
:gbpma_zpos
 
:gbpma_zpos
 
:gbpmb_zpos
 
:gbpmb_zpos
 
:gbpmc_zpos
 
:gbpmc_zpos
  
−
;             Fast Raster calibration constants
+
; Fast Raster Calibration Constants
−
;            =================================
 
 
:gusefr              = 1   
 
:gusefr              = 1   
−
; flag if 1 fast raster data used with average beam pos and angles in
+
:: flag if 1 fast raster data used with average beam pos and angles in calculating beam position. If 0 then only use average beam pos and angles in calculating beam position
−
; calculating beam position
+
: gfr_cal_mom
−
; if 0 then only use average beam pos and angles in calculating beam position
+
: gfr{x,y}{a,b}_adc_zero_offset
−
; Various fast raster quantities: gUse* are flags
+
: gfr{x,y}{a,b}_adcpercm
−
; Raster constants determined from coin run 4556 on Aug 20, 2018
 
−
; gfr_cal_mom  = 8.518
 
−
; gfrxa_adc_zero_offset = 64150
 
−
; gfrxb_adc_zero_offset = 66250
 
−
; gfrya_adc_zero_offset = 67700
 
−
; gfryb_adc_zero_offset = 64100
 
−
; gfrxa_adcpercm = 158000
 
−
; gfrxb_adcpercm = 147000
 
−
; gfrya_adcpercm = 155500
 
−
; gfryb_adcpercm = 157500
 
−
  gfr_cal_mom  = 6.4  ; = beam momentum during jan 2018 3 pass
 
−
  gfrya_adcpercm = (77755.-57411.)/.2;
 
−
  gfryb_adcpercm = (71093.-52056.)/.2;
 
−
  gfrxa_adcpercm = (75733.-51938.)/.2;
 
−
  gfrxb_adcpercm =  (79778.-57293.)/.2;
 
−
  gfrya_adc_zero_offset = (77755.+57411.)/2.;
 
−
  gfryb_adc_zero_offset = (71093.+52056.)/2.;
 
−
  gfrxa_adc_zero_offset = (75733.+51938.)/2.;
 
−
  gfrxb_adc_zero_offset = (79778.+57293.)/2. ;
 
 
; positions of FR magnets relative to target
 
; positions of FR magnets relative to target
−
  gfrx_dist  = 1375  ; cm
+
:  gfrx_dist  = 1375  ; cm
−
  gfry_dist  = 1337  ; cm
+
:  gfry_dist  = 1337  ; cm
  
 
==Spectrometer General Parameters==
 
==Spectrometer General Parameters==
 
===Spectrometer GEN Files===
 
===Spectrometer GEN Files===

Revision as of 12:32, 27 September 2021

General Parameters

General parameters are broken into two categories; parameters that are not spectrometer specific, and those that are spectrometer specific.

  • All general parameters are included using the general.param file located at:
DBASE/<spec>/
  • Global general parameters used for the hall C beamline and debug modes are stored in:
PARAM/GEN/ directory.
  • Spectrometer specific general parameters are included at:
PARAM/SHMS/GEN/
PARAM/HMS/GEN/

Non-Spectrometer General Parameters

As the name implies, these do not deal with the specific spectrometer, but rather the beamline or target componenets. There used to be energy loss parameters included in this directory for the old Fortran analyzer. The C++ analyzer no longer calculates energy loss, so the variables associated with energy loss have been removed.
The main parameters of this section are the BCM scalers and the BPM positions from HARP scans and the raster conversions. These aspects have their own devoted analysis section.

Global GEN Files

  • PARAM/GEN/genflags.param
    Only includes the gen_run_starting_event parameter.
  • PARAM/GEN/gdebug.param
    No used parameters
  • PARAM/GEN/gtarget.param
    No used parameters, Eloss not included in hcana. Eloss handeled in rc-externals
  • PARAM/GEN/gscalers.param
    Calibration of scaler BCM branches. Must be set before running the BCM calibration procedure.
  • PARAM/GEN/gbeam.param
    Calibration of beam position on target and raster settings.

gscalers

The gscalers.param file currently only includes BCM calibration information. In theory, there could be other scaler calibrations here, but it is unlikely this will change. BCM calibrations are typically applied on a specified run-range based on a BCM calibration run. The gscalers.param Main Parameters:

  • gNumBCMs = 6
  • gBCM_Names = " BCM1 BCM2 Unser BCM4A BCM4B BCM4C"
  • gBCM_Gain = 4795.0, 4092.0, 4000.0, 13020.0, 2042.0, 6238.0
  • gBCM_Offset = 250300.0, 250200.0, 393000.0, 432.4, 204.9, 127.8
  • gBCM_Current_threshold = 5.0
  • gBCM_Current_threshold_index = 3

The naming of these variables is different than any other variable in hcana because of their capitalized letters. Additionally, No other detector has space-separated names like this one does.

gbeam

The gbeam parameter files include information related to the surveys of absolute beam position using HARP scans and the EPICS RAW BPM variables. The naming of these parameters is self-explanatory, but the sign on many of the parameters is not straight forward because the difference in coordinate systems in the hall. Refer to the BPM calibration procedure for specifics on this.

Hall C EPICS RAW BPM values in units of cm
gbeam_{x,y}
gbeam_{xp,yp}
Hall C BPM A, B, and C, slope and offsets based on HARP scans
gbpm{x,y}{a,b,c}_slope
gbpm{x,y}{a,b,c}_off
positions of BPMs relative to target determined from Survey and Alignment
gbpma_zpos
gbpmb_zpos
gbpmc_zpos
Fast Raster Calibration Constants
gusefr = 1
flag if 1 fast raster data used with average beam pos and angles in calculating beam position. If 0 then only use average beam pos and angles in calculating beam position
gfr_cal_mom
gfr{x,y}{a,b}_adc_zero_offset
gfr{x,y}{a,b}_adcpercm
positions of FR magnets relative to target
gfrx_dist = 1375 ; cm
gfry_dist = 1337 ; cm

Spectrometer General Parameters

Spectrometer GEN Files

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