Perp live time problems

Using the the old 1MHz scaler the dead time slope was unstable. After switching to the original 1MHz scaler the jumps in the lower run numer perp runs gets fixed. There still is a jump between 72524 and 72533 that I don't understand. Also, starting at around run 72488 the dead time is really high. I think it is related to the beam steering issue associated with the jump in rates found here. Not totally sure what was going on but it seems to be related to the scaler fix or perhaps better beam steering? The Prescale factors were not set correctly. Also, starting at 72532 the coda flag "cosmics" was set to get the HMS singles.

A jump in livetime slope from fit is clearly wrong. You can see the slope is good at run 72624 but strange (and not pointing to (0,1) for run 72631. Starts after run 72624. Bigcal led run starts at run 72626. The jump goes away between runs 72640 and 72644. Perhaps it is related to the removal of "laser" in coda? Would "laser" have been added to do a bigcal LED run?

On the whole I am using a single live time fit for parallel runs and a single fit for perpendicular runs. However there is certainly room for improvement.

Some A1 results

You can find the A1 results for 4.7 and 5.9 GeV beam energies below. Does not yet include any corrections for positrons or radiative corrections.

[ICO]NameLast modifiedSizeDescription

[PARENTDIR]Parent Directory   -  
[IMG]livetime_vs_run_2.png 2015-01-09 17:56 8.8K 
[IMG]livetime_vs_run.png 2015-01-09 17:56 8.0K 
[IMG]livetime_vs_rate_2.png 2015-01-09 17:56 8.3K 
[IMG]livetime_vs_rate.png 2015-01-09 17:56 7.4K 
[IMG]livetime_slope_vs_ru..>2015-01-09 17:56 6.5K 
[IMG]livetime_slope_vs_ru..>2015-01-09 17:56 7.4K 
[IMG]livetime_slope_vs_ru..>2015-01-09 17:56 6.5K 
[IMG]livetime_counts_vs_r..>2015-01-09 17:56 7.3K 
[IMG]livetime_counts_vs_r..>2015-01-09 17:56 7.5K 
[IMG]livetime_72555.png 2015-01-09 17:56 5.6K 
[IMG]ionchambers_location..>2015-01-09 17:56 92K 
[IMG]ion_chambers_72500_7..>2015-01-09 17:56 34K 
[IMG]ion_chambers_72449_7..>2015-01-09 17:56 44K 
[IMG]ion_chambers_72448_7..>2015-01-09 17:56 45K 
[IMG]compare_A1_para59_0.png2015-01-09 17:56 46K 
[IMG]compare_A1_para47_0.png2015-01-09 17:56 50K 
[IMG]LiveTime_72915.png 2015-01-09 17:56 57K 
[IMG]LiveTime_72631_old_1..>2015-01-09 17:56 47K 
[IMG]LiveTime_72631.png 2015-01-09 17:56 47K 
[IMG]LiveTime_72624.png 2015-01-09 17:56 56K 

Ionization chambers

As follow up I have checkout the ionization chambers. The plot on the right is run 72425 (which is a good run). The plot on the left is the listed problem run.

  1. 72448
  2. 72449
  3. 72500
Here is a reference of the chamber locations:

There doesn't seem to be any big differences between the two.