[d2n-analysis-talk] LHRS S1,S2 TDCs (Problem Solved)

[David Flay]

Problem solved --

Brad was right -- there was an error in the DB file...

Turns out, the db_L.s1.dat AND the db_L.s2.dat files have the wrong slots
listed for each DB directory AFTER 3/6/09.  So, I will adjust 3/9/09
through the end of the experiment.  I discovered this through:

[dflay at dflay:20090309]$ diff db_L.s1.dat
/home/dflay/d2n_analysis/d2n/DB/20090213/db_L.s1.dat

7,8c7,8
<        4       9       8       13      1             - TDCs pads 1-6 
(right)
<        4       9       0       5       7             - TDCs pads 7-12
(left)
---
>        4      18       8       13      1             - TDCs pads 1-6 
(right)
>        4      18       0       5       7             - TDCs pads 7-12
(left)

where the second file in the diff command is the 'correct' file -- it has
TDCs.

Similarly, for db_L.s2.dat:

[dflay at dflay:20090309]$ diff db_L.s2.dat
/home/dflay/d2n_analysis/d2n/DB/20090213/db_L.s2.dat

9,10c9,10
<        4       9      32      47       1      1875   - TDCs pads 1-16
(right)
<        4       9      16      31      17      1875   - TDCs pads 1-16
(left)
---
>        4      18      32      47       1      1875   - TDCs pads 1-16
(right)
>        4      18      16      31      17      1875   - TDCs pads 1-16
(left)


Also -- I checked every single DB directory, and other than the dates I
mentioned, all S1 DB files are consistent.  However, for 2/6/09 and 2/8/09
I get a difference on the TDC time offsets and the timewalk factors are
different:

dflay at dflay:20090206]$ diff db_L.s2.dat
/home/dflay/d2n_analysis/d2n/DB/20090213/db_L.s2.dat

19,22c19,22
<     708.32 630.53 547.52 575.01 466.63 471.96 573.65 560.03
<     552.44 540.00 448.87 404.40 628.02 555.73 491.81 513.93 - Left Paddles
<     614.68 417.74 430.62 484.41 637.07 669.91 689.18 644.28
<     674.43 562.61 642.89 814.94 662.55 586.61 676.87 689.88 - Right Paddles
---
>     708.32 647.29 592.85 593.04 517.08 515.84 624.01 606.75
>     611.64 590.49 513.47 419.92 660.55 590.72 546.92 547.46 - Left Paddles
>     614.68 434.49 475.95 502.44 687.52 713.80 739.55 691.01
>     733.62 613.11 707.49 830.48 695.09 621.60 732.00 723.42 - Right Paddles
34c34
<      1.37097e+08
---
>      1.34281e+08
40,45c40,45
<          10.555e-09 12.442e-09 11.254e-09 11.707e-09 10.799e-09 9.941e-09
<          11.828e-09 11.251e-09 10.966e-09 10.568e-09 11.496e-09 10.656e-09
<          11.262e-09 9.255e-09 10.528e-09 10.555e-09 10.555e-09 12.442e-09
<          11.254e-09 11.707e-09 10.799e-09 9.941e-09 11.828e-09 11.251e-09
<          10.966e-09 10.568e-09 11.496e-09 10.656e-09 11.262e-09 9.255e-09
<          10.528e-09 10.555e-09
---
>          2.7504e-08 4.1557e-08 2.7405e-08 4.6107e-08 2.7029e-08 3.1715e-08
>      2.7119e-08 3.7139e-08 4.3887e-08 4.1614e-08 2.8297e-08 2.8487e-08
>          2.8668e-08 2.0924e-08 3.3868e-08 2.5691e-08 0.0000e-09 0.0000e-09
>      0.0000e-09 0.0000e-09 0.0000e-09 0.0000e-09 0.0000e-09 0.0000e-09
>      0.0000e-09 0.0000e-09 0.0000e-09 0.0000e-09 0.0000e-09 0.0000e-09
>      0.0000e-09 0.0000e-09

Now, the main question is -- I remember getting an e-mail from Vince
concerning the S2m calibration - w.r.t. time offsets.  I have his code to
do it... Is it worth running through this first?  I'd rather have the
right histograms to look at before using them, if there's anything to gain
from using the scintillators...  However, if I'm not mistaken, correction
to this calibration will have most to do with the determination of beta,
and beta looks pretty good (~0.96) you can see that plot here (from an old
talk, pg. 4):

http://www.jlab.org/~flay/analysis/2009/LHRS_9_15_09.pdf

Thanks,

Dave


-------------------------------------------------
David Flay
Physics Department
Temple University
Philadelphia, PA 19122

office: Barton Hall, BA319
phone: (215) 204-1331

e-mail: flay at jlab.org
            flay at temple.edu

website: http://www.jlab.org/~flay
              http://quarks.temple.edu
-------------------------------------------------