01/31/2002

Target lab status:

• Work finished: (Vince and Patricia)

-Sergei ruptured on Monday, around 2:30pm, for details, please read tlog entry  #213   ;
-Adjust oven PID control;
-25 cm reference cell (used during A1n) was sent to RadCon, prepare for wall thickness measurement at UVa;
• List to do:

-Patricia will continue working on PID settings of oven controller, Kevin suggested doing adjustment with cell in, and try "auto PID" option;
-Vince will do RF calibration on friday, then do water calibration during weekend; He is also working on fit programs;
-Next week, put one cell (possible options: Queen Mary/Sally/Brunhilder/?King William), start fiber optics setup for EPR;

g2n Analysis: (Kevin)

• Did acceptance cut dependence study for kinematics #1 and #2, very small effect on parallel asymmetries,  ~<1 sigma effect on perpendicular asymmetries.  All effects look like statistical fluctuation;

A1n Analysis: (Xiaochao)

• Work completed:

-x-section: left arm data < MC, right arm data > MC;
-Subtract N2 dilution from refcell 3he runs, now pressure curve looks very reasonable (very small offset at zero pressure); Polarized He3 production elastic run vs. pressure curve: left arm - very close; right arm: pol3he higher than curve;
-Use Gore wall thickness data from UVa, but this did not solve the difference between two arms;
-Use reference cell wall thickness data from Vince (EEL) for ref cell runs;
-Due to the descrepancy between MC and data on right arm, large phi_target part (0.02<phi_targ<0.03), did several studies trying to pin down the problem:
• check target var histograms, shower/preshower distribution - did not find anything abnormal;
• do elastic analysis with small targ_phi cut, change cut from abs(phi)<0.03 to abs(phi)<0.02; now x-section: left arm data < MC, right arm data = MC (almost);
• But from pressure curve, left arm is good, right arm, pol3he run is still higher than curve;
-Found result is very senstitive to wall thickness, need to check it more;
• List to do:

-check W3he cut dependence;
-check deadtime correction (using T3accpt, T4accpt from data);

---

01/24/2002

Target lab status:

• Work finished: (Vince)

Sergei lifetime analysis.
Temperature test analysis;
Oven controller;
• Result:

Sergei lifetime (AFP loss corrected) is 33.97 hours;
A bug in temperature test analysis is fixed, calibration constant for Sergei is 3.95mV/%, gives maximum NMR~48% (EPR ~ 45% using new temperatures);
Oven: Now it takes ~ 30 minutes to stablized to +/- 1 degree;
• List to do:

Vince will adjust PID parameter settings in oven controller;
Wall thickness measurement for Sergei, then Sergei will be sent back to W&M;
Start fiber optics setup (purchase fiber coupler etc..);
• Core people need to sit down and discuss a long-range plan for target lab work.

g2n Analysis: (Kevin)

• Did pid cut dependence study for kinematics #1 and #2, almost no dependence has been observed;
• List to do:

Continue pid cut study for other kinematics;
Start acceptance cut dependence study;

Target Analysis: (Kevin)

• Study of water calibration with different lock-in phase;

A1n Analysis: (Xiaochao)

•  BPM correction for elastic analysis:

Beam position offsets and radius have been extracted for commissioning runs, will be used as an input to espace;
Before full BPM correction  through espace, effect of BPM has been estimated by adding beam position offset in MC simulation.  For a typical beam offset, acceptance changed by 2% on left arm and 1% on right arm, x-section changed by 1E-3;
Full BPM correction in espace is possible (need help from Bodo), and necessary.  It is also possible to add window in ev_time so correction can be done even if there is a large shift during one run.
• Pressure curve:

N2 and He3 pressure curve (xsection*density vs. density) - both have positive offset at zero pressure.
Polarized He3 production elastic run is significantly higher than He3 pressure curve;
• List to do:

check ref. cell wall thickness and add it to MC;
check Gore wall thickness on left/right sides;

01/17/2002

Target lab status:

• Work finished: (Vince)

Did 2nd Sergei lifetime measurement;
Did 2nd temperature test analysis;
Oven controller;
• Result:

Sergei lifetime (AFP loss NOT corrected) is 33 hours;
It takes ~ 1 hour for oven to stablize whenever lasers are turned on/off, not good enough for a reliable temperature test;
• List to do:

Vince will try to fix the oven;

A1n Analysis: (Xiaochao)

•  BPM correction for elastic analysis:

Beam position dependence is observed in elastic analysis;  Need to check if event-by-event bpm correction is necessary.  In the worst case need to run espace two times to do event-by-event correction.

g2n Analysis: (Kevin)

• Empty ref cell run analysis, try to remove window through histogram subtraction of pol3he runs and empty cell runs.

---

01/10/2002

Target Lab Status:

• Work finished: (Vince, Patricia, Jindong)

• Results:

A1n Analysis: (Xiaochao)

• Elastic analysis:

g2n Analysis: (Kevin)

• BPM info cannot be put into CWN files, need to modify espace source code; Apparently Nilanga doesn't have time to do it;