GeN (93-026) Archive

Required reading

Gen01 COO

Gen01 ESAD

Other Links

Collaboration Meeting May 14, 2001

Collaboration Meeting December 8, 2000

Draft of paper submitted to PRL (on March 26, 2001) placed here

Draft of PRL

Referee Report

Response to Referee Report

Revised Draft of paper submitted to PRL (on June 4, 2001) placed here

Revised Draft of PRL

Paper accepted and published by PRL placed here

Published in PRL


Neutron Detector
Polarized Target
Analysis
Arenhoevel Plots (J. Mitchell)
Chicane and Beam Line
Chicane Settings
Survey Information
Basel BPM article
Basel TBPM user manual
Technical Notes
Gen98 Online Documentation
Safety Documents
The Proposal
Collaboration
Possible Kinematics
Administrative Stuff
Figures for Talks
Photo gallery


Administrative Stuff
Collaboration List
Run Coordinators Responsibilities


Kinematics of Gen
    The kinematics of Gen are essentially those of quasielastic scattering from the deuteron.  However the polarized target magnet has a limited aperature and restricts the freedom to select incident beam and electron scattering angles. The target polarization axis (the direction of the B field) is kept perpendicular to the q-vector. This requires that the magnet be rotated in the lab.  Further, the rastering of the beam limits the rotation to less than the maximum of 97/2 degrees  (since the accident; it was 50 degrees before) to prevent the incident beam from striking the superconducting coils. The raster clearance must be at least 2 mm.

Note that there is a Figure of Merit that is also used to determine the kinematics chosen for the experiment. Further, for the upcoming run there are contraints which arise from the location of R.Madeys detector hut which is to be used for both GeN experiments.

The links below yield a table of the kinematics and the figure summarizes the restrictions.

Figure summarizing the Q^2 and theta possible with a fixed raster clearance and three upper limits on beam energy.  The 6 Gev beam (in red) provides the greatest flexibility. Postscript version.

Table   of kinematic values and "book asymmetries" for elastic scattering from the neutron.
The variables  are q2     theta    ei      ef     dq    d_costq   thr   th_field   pr     beta     ke    clrnce Clr?  sigep    sigen      gen     gmn     gep     gmp     A_v     Dgdasq.
For those that need explaining:
thr            recoil angle (direction of q vector)
th_field     rotation of the magnetic field in lab to keep the poalrization axis perpendicular to q-vector
pr            recoil momentum
beta         beta of particle
ke            kinetic energy
clrnce      Clearance of beam (including raster) from target coils (must be greater than 0.2 cm)
Clr?        Answers the question implied above
sigep        elastic electron proton scattering assuming IJL for proton
sigen        elastic electron neutron scattering assuming dipole for magnetic and Galster for electric
gen, gmn, gep, gmp    Form factors assuming dipole for all and Galster
A_v        vector asymmetry for neutron
Dgdasq    Sensistivity factor of A_v (Partial derivative of g - defined to be ratio of Gen/Gmn -  with respect to A_v) squared. Critical to determination of the FOM. More below.

If you get this file you can plot all sorts of stuff using Gnuplot or some other package. For example to plot the incident beam energy versus theta for a q2 = 0.400 do this:

 plot 'gen_kinematics.tbl' using 2:($1 == 0.400 ? $3: 1/0) t 'E_i versus theta for fixed Q^2'

or to plot the electron prton elastic cross section versus theta for a fixed q2  = 1.00 do this:

 plot 'gen_kinematics.tbl' using 2:($1 == 1.00 ? $14: 1/0) t 'sigep versus theta for fixed Q^2 = 1'

 or to  plot the reciprocal of dgdasq versus theta for a fixed q2 = 1.00 do this:

plot 'gen_kinematics.tbl' using 2:($1 == 1.00 ? (1/$20): 1/0) t '(dgdasq)^-1 versus theta for fixed Q^2 = 1'



Figure of Merit
 The figure of merit for Gen arise from an analysis of the relationship between GeN and the experimental asymmetry.  You can find this relationship in the original proposal andin the document linked below.

Optimization of Kinematic Conditions for JLAB Experiments


The Proposal (April 1993)

Status of World Data (figure provided by D. Hingbotham) (jpg) (ps)



Safety Documents

Conduct of Operations (1998)
Safety Assessment Document (1998)
Conduct of Operations (2001)
Safety Assessment Document (2001)



Technical Notes

Oscar Rondon
 Angular dependence of asymmetry
 Sensitivity of asymmetry to approximations
 F.o.M. for GEp
 GEp,n by absolute cross sections
 Kinematics summary for GEn
 All GEn runs database DBF IV format
Summary of hclog entries on shielding for GEn
Associated summary table of shield configurations  here
Technical Note summarizing the shielding

Marco Zeier
 Asymmetries by Helizity pairs
Data Acqusition Review (CODA)
Electronics Review
 

Ingo Sick
 Memo on Dilution Factor
 Memo on Insentivity of the Asymmetry
 Target Field Alignment Study Results

Tom Eden and D. Madey
Optimization of Kinematic Conditions for JLAB Experiments....
Neutron Detector Efficency - KSU code  (Tom Eden)

Packing Fraction (Chris Harris)
Description of Neutron Detector related kumacs (Glenn Warren)

Primer and silo and farm perl scripts (GlennWarren)

Guideit Results (Ken McFarlane)

Target Field Optics Studies  (Markus Mühlbauer)



Analysis

Beni Zihlmann's Analysis Pages
 

Individual Triggers

Align gamma peaks



Glenn Warren's Analysis Efforts

"I hope to continue "publishing" my results on the web.  There will be an
index of topics at:"

Index of topics


Arenhoevel Plots

These plots were produced by Joe Mitchell from the calculations sent to us by H. Atenhoevel.

Description forthcoming

aren_ang.ps
aren_calc.ps
aren_eprime.ps
aren_eprime_diff.ps
aren_fsi_diff.ps
aren_mec_diff.ps
aren_rc_diff.ps
aren_z_eprime.ps
aren_z_full.ps


Neutron Detector






Photos
Back of Neutron Detector
Gang of Three
Side View
Again
Up Close and Front

Technical Notes

Neutron Detector Electronics

Neutron Detector Electronics Logic
  Petitjean (5/28/98)
Neutron Detector Cosmic Trigger

Neutron Detector Timing

Neutron Detector Splitter Arrangement
Petitjean (5/28/98)
Neutron Detector Cabling
Warren (7/8/98)
Neutron Detector Layout
Warren and Petitjean (6/4/98)
Neutron Detector Layout (Post Experiment)
Warren and Petitjean (12/1/98)
Base Electronics Design

Memo on Electronics Deadtime (Zeier and Petitjean)

Memo by Ken Mcfarlane on PMT currents

Ken McFarlane's Gen Pages
These have to do with the neutron detector electronics

Trigger Logic Relative Timing (Post Experiment)
Warren and Petitjean (11/15/98)

Neutron Detector Logic
Warren and Petitjean (12/3/98)

Delay Boxes Setup (Retiming)
Warren and Rohe (11/17/98)

Lead Shielding
Layout of Lead Shielding (drawing) by D. Rohe
Lead Shielding (Photo)
Downstream of Target (Photo)
 

Scaler Figures

Helicity Map Figures
Helicity_map.ps
Helicity_circuit_1.ps
Helicity_circuit_2.ps
 


Polarized Target

Polarized Target Facts
Operating Procedures
Annealing Procedure
Magnet Fill
LN2 Fill Procedure
NH3 Information (by Al Tobias)
Materials in Path of Electron
Polarization Data



Target Figure
NMR Schematic
E143 Target insert
 

Photos of Target
Top of Target
EIO Tube and microwave circuit
Target Can



 
 

Moller Polarimeter











Neutron Detector LogBook Entries

 5733 05/28/98 12:26 petitjean Detector-Channel assignment at the splitter
 5728 05/28/98 12:15 petitjean GEN N-Detector Electronics
 5732 05/28/98 12:24 petitjean Timing Neutron-Electron
 5733 05/28/98 12:26 petitjean Detector-Channel assignment at the splitter
 5736 06/12/98 16:27 cdaq neutron detector cabling
 5737 06/12/98 17:32 cdaq neutron detector positioning
 5738 06/12/98 17:37 cdaq tosp for neutron detector
 5764 06/18/98 15:15 zihlmann HV Neutron Detector
 5768 06/19/98 00:23 Steinacher Mapping neutron detector
 5784 06/19/98 19:20 gwarren Mapping neutron detector
 5794 06/20/98 06:25 mcfarlan Neutron detector PMT current
 5800 06/20/98 09:24 mcfarlan Neutron Detector rates
  5829 06/21/98 10:23 mcfarlan Neutron discriminator thresholds
 5830 06/21/98 11:04 cowley neutron bar HV and thresholds
  5837 06/21/98 12:49 cowley neutron detectors threshold
5886 06/22/98 01:34 mcfarlan N detector bar rates, PMT currents
5887 06/22/98 01:39 mcfarlan N detector paddle (veto) rates
5888 06/22/98 01:41 mcfarlan N detector rates
5956 06/24/98 15:02 gwarren Increased ndet HV by 100 V
5982 06/26/98 09:00 gwarren Spot Checked ndet map file
5981 06/26/98 01:43 mcfarlan HMS and ND gates, scalers
 5991 06/26/98 15:11 zihlmann bar4 plane4 left dead adc channel
  6001 06/26/98 18:44 cowley neutron delays
  6041 06/27/98 10:49 Mitchell N detector stuff
 6045 06/27/98 11:47 mcfarlane Delays for different kinematics
  6057 06/27/98 14:29 donal neutron electronics discriminator
  6059 06/27/98 15:32 gwarren Change in map filename
  6062 06/27/98 18:03 mitchell N-det shielding
  6333 06/30/98 12:51 Rondon N detector, plastic, shielding, PMT currents
  6079 06/27/98 22:20 cowley anode currents on neutron detectors at nominal luminosity
  6063 06/27/98 18:37 mitchell anode currents at nominal lum
  6082 06/27/98 22:38 cmh7k anode current measurement summary
  6079 06/27/98 22:20 cowley anode currents on neutron detectors at nominal luminosity
  6166 06/29/98 00:05 lcsmith ndet gain matching
  6208 06/29/98 08:50 gwarren Time resolution in ndet crate is 50 ps
  6219 06/29/98 12:59 mcfarlan HMS S2 and ND time
  6231 06/29/98 15:32 mcfarlan ND and HMS gates
  6234 06/29/98 16:30 mcfarlan Paddle 33-48 Left
  6235 06/29/98 16:40 mcfarlan Pulse widths on bars and paddles
  6260 06/30/98 00:13 Cdaq NDET studies
  6327 06/30/98 11:55 gwarren keyword=PMT anode currents
  6324 06/30/98 11:24 mcfarlan PMT anode currents
6333 06/30/98 12:51 Rondon N detector, plastic, shielding, PMT currents
  6346 06/30/98 16:15 gwarren Proton Energy Loss in nDet
  6369 06/30/98 23:48 LC Smith NDET studies
  6372 06/30/98 23:58 donal day neutron timing
  6418 07/01/98 16:16 mcfarlan NDC TDC modifications
  6420 07/01/98 16:49 mcfarlan ND FastBus TDCs moved! MAPS need to be changed.
  6423 07/01/98 18:43 zhuhg Map has been updated
  6440 07/02/98 17:39 mcfarlan HMS-ND cross-timing
  6445 07/03/98 12:53 mcfarlan HMS-ND crosstime
  6445 07/03/98 12:53 mcfarlan HMS-ND crosstime
  6446 07/03/98 13:02 mcfarlan Paddle delays, cables.
  6447 07/03/98 13:09 mcfarlan Remove termination of output from PMT base
  6450 07/05/98 09:59 Zhuhg Cole's columnized ntuple installed on cdaq account analysis code
  6456 07/05/98 16:05 gwarren Fixed some bad ndet channels
  6514 07/08/98 23:20 gwarren Length of ndet cables
  6515 07/08/98 23:22 gwarren Length of ndet cables (continued)
  6516 07/08/98 23:28 gwarren 50 Ohm terminated ndet bases
  6517 07/08/98 23:29 gwarren Replaced base for ndet P14R
  6526 07/09/98 17:58 mcfarlan N detector paddle and bar cables
  6572 07/11/98 11:43 gwarren All channels in ndet working
  6683 07/17/98 16:16 gwarren Measured self-timing time resolution of ndet
  6724 07/19/98 06:08 gwarren Adjusted ndet TDC start and ADC gate
  6728 07/19/98 07:42 cdaq ndet annode currents
  6834 07/23/98 09:23 gwarren Energy Uncertainty due to Pedestal Width
  6837 07/23/98 11:52 gwarren Proton Energy losses in ndet
  6959 07/26/98 01:11 gwarren Paddle anode currents with chicane

  7078 07/29/98 20:26 gwarren Recabled HMS TDCs

7079 07/29/98 21:29 gwarren Length of ndet cables, corrected
  7080 07/29/98 21:33 gwarren ndet cable lengths, corrected (part 2)
  7109 07/31/98 22:57 mitchell Post shielding anode currents

  7148 08/01/98 19:53 cowley PMT anode currents
  7149 08/01/98 20:02 cowley Paddle raw rate problem
  7159 08/01/98 23:06 hauger n-det thresholds checked

  7183 08/02/98 04:18 khandaker N-detector Rate Studies
  7209 08/02/98 09:37 Zhuhg TDC cross link from run 20909, looks weird
  7268 08/02/98 23:09 cowley n det rate vs raster
  7274 08/03/98 00:16 cowley more n det vs raster
  7314 08/03/98 18:58 zhuhg ND hit pattern per plane: P1 and P2
  7315 08/03/98 19:00 zhuhg ND hit pattern per plane:(P3 and P4)
  7316 08/03/98 19:01 zhuhg ND hit pattern:P5 and P6
  7317 08/03/98 19:04 zhuhg ND hit pattern: plane 7
  7325 08/04/98 02:51 Eden, ndet
  7342 08/04/98 06:39 Lichtenstadt n det
  7388 08/05/98 02:52 Jechiel ndet
  7443 08/06/98 10:46 Lung Some Neu Det HV off run 21089 and 21090
  7462 08/06/98 15:31 gwarren ndet HV controls crash
  7454 08/06/98 12:44 Lung Neutron det plane 3 pedestal problems?
  7564 08/08/98 03:40 gwarren ndet discriminator threshold
  7565 08/08/98 03:48 gwarren ndet pedestal width
  7567 08/08/98 03:54 bernet Ndet bars threshold
  7572 08/08/98 04:17 bernet Ndet bars thresholds : 75 mv
  7592 08/08/98 13:32 gwarren ndet Threshold correction
  7648 08/10/98 08:55 Eden Neutron Detectors
  7694 08/11/98 13:04 gwarren ndet anode currents with 4th sheet of lead
 7696 08/11/98 14:08 gwarren ndet Rates for P14/B14 with new shielding

  7726 08/12/98 21:48 gwarren ndet Paddle Disc Thresholds
  7729 08/12/98 22:19 gwarren ndet Bar Disc Thresholds
  7731 08/12/98 22:53 gwarren ndet Thresholds set to 30/75 mV.
  7825 08/15/98 03:03 gwarren ndet cable swap fixed
 7838 08/15/98 15:04 cdaq What about PMT anode currents?
  7845 08/15/98 19:08 gwarren Correction on cable swap

  7858 08/17/98 14:20 gwarren Anode Currents of Paddles
  7992 08/20/98 00:20 gwarren Paddle Efficiencies

  7993 08/20/98 00:38 gwarren Paddle Proton Efficiencies
  7992 08/20/98 00:20 gwarren Paddle Efficiencies
  7994 08/20/98 00:53 gwarren ndet Single Event Display updated

  8033 08/20/98 10:19 mitchell shielding on skyhook

  8041 08/20/98 13:14 gwarren ndet TDC start details

  8060 08/20/98 15:37 Chant Missing Paddles

  8042 08/20/98 13:20 Chant Missing Paddles
  8074 08/20/98 19:46 Lung Attempts to localize background source
  8088 08/20/98 23:34 Lung Results of alum collar on ndet rates
  8089 08/20/98 23:43 Lung Beamline sketch
  8113 08/21/98 14:14 mcfarlan HMS to ND cross timing
  8119 08/21/98 16:16 mcfarlan NDC ADC gate length change
 8191 08/22/98 20:52 LC Smith ADC gate width

  8138 08/21/98 23:42 LC Smith ADC gate width

  8191 08/22/98 20:52 LC Smith ADC gate width

  8267 08/24/98 03:06 zihlmann Paddle 18 plane 1
  8254 08/23/98 23:51 LCSmith Missing paddle

  8269 08/24/98 03:41 zihlmann Paddle 18 problem
  8291 08/24/98 13:22 gwarren Hopefully fixed Paddle 18 problem
  8296 08/24/98 14:24 gwarren Something strange in Paddles
  8323 08/25/98 03:25 gwarren Proton Veto Efficiencies and ADC gate width
  8372 08/30/98 13:02 gwarren Shifted ndet TDC start to 5 ns earlier.
  8373 08/30/98 13:24 gwarren ndet gain matching

  8377 08/30/98 14:12 gwarren ndet gain matching.

 8450 09/01/98 18:29 McFarlane ND ADC gate length 47 ns
  8530 09/02/98 15:39 gwarren ndet catches 52 +- 3% of protons
 8455 09/01/98 19:36 gwarren How many protons make it into the ndet
  8530 09/02/98 15:39 gwarren ndet catches 52 +- 3% of protons

  8560 09/03/98 05:08 khandaker Missing NDET Scalers
  8578 09/03/98 12:51 gwarren Missing ndet scalers
  8578 09/03/98 12:51 gwarren Missing ndet scalers
  8607 09/03/98 23:30 mcfarlan ND-HMS delay at 8LM
  8609 09/03/98 23:43 mcfarlan ND-HMS delay at 8LM

  8621 09/04/98 02:26 gwarren Reestablished ndet thresholds
 

  8634 09/04/98 06:25 gwarren No protons in ndet for HMS singles
  8751 09/06/98 07:09 gwarren ndet HV set to values from 98/8/12.

  8805 09/08/98 15:25 Jechiel N-detector shielding
  8858 09/09/98 15:46 gwarren Neutron Count Rate, Part I
  8859 09/09/98 15:58 gwarren Neutron Count Part II
  8862 09/09/98 16:42 gwarren Proton Count Rate
  8950 09/11/98 09:31 gwarren Rebinned Neutron Distribution
  8956 09/11/98 11:08 gwarren Proton leakage in neutron spectra.
  9079 09/15/98 21:33 Zhuhg d(e,e'p) PROTON RATES DUE TO TARGET FIELD

  9097 09/16/98 11:34 gwarren Fiducials Points for Ndet
  9098 09/16/98 11:34 gwarren Ndet position for Q2=1.0
  9105 09/16/98 18:10 Cdaq Neutron Tof and timing for q2=1
  9138 09/17/98 20:52 kaufmann HMS Single Rate
  9142 09/17/98 22:18 kaufmann Ndet Single Rates

  9193 09/19/98 19:47 rohe veto efficiencies

  9208 09/20/98 13:34 csa Neutron path/vel meantime corrections in code, new offsets

  9219 09/21/98 09:20 csa Rough walk correction in online code

  9222 09/21/98 11:07 csa pretty pics for 9208, 9221

  9223 09/21/98 11:12 csa pretty pics, cont'd

  9317 09/27/98 05:42 gwarren Veto Efficiencies for Q2=1.0

  9475 09/30/98 15:15 Zhuhg target field effect on d(e,e'N) rate preview

  9480 09/30/98 17:59 Zhuhg What target field do to electrons

  9510 10/01/98 16:16 csa NDET plane 2 number 8 is missing
  9513 10/01/98 16:45 csa NDET plane 2 number 8 was never gone
  9517 10/01/98 22:05 gwarren Proton Energy Losses in ndet for Q2=1.0
  9543 10/02/98 15:59 Zhuhg (e,e'p) rate at first bar plane w/ and w/out target field(final words)
 

Beam Line
 5723 05/06/98 10:50 Mack SEE bpm changes in progress

  5788 06/20/98 00:36 mack more bcm progress
 
 
 
 
 

Raster

  5752 06/18/98 02:30 Anklin fast raster

  5754 06/18/98 03:23 Anklin fast raster ok

  5755 06/18/98 03:39 Anklin fast raster FSD trip

  5763 06/18/98 14:57 ZIHLMANN RASTER fast and slow
 
 
 

Survey
  7092 07/31/98 09:32 mack Gen survey stuff
 
 
 

Target Encoders
  5828 06/21/98 09:53 mitchell target encoders
5766 06/18/98 16:53 mitchell encoder calibration-tgt lifter
  6261 06/30/98 00:36 zhuhg Target move down by 2mm
  6274 06/30/98 04:19 muehlbauer Target moved down to -2mm
6004 06/26/98 19:47 cmh7k target encoder positions
9169 09/18/98 18:23 cmh7k survey, target position, etc.
  9306 09/27/98 02:37 kaufmann target encoder position
  9310 09/27/98 03:13 gwarren Vertical Position of Target
9170 09/18/98 20:21 Cdaq Beam Line Survey