Timing, PID and Trigger Check Instructions 

• You need to first run online analysis to generate the rootfile. To get good histograms, 100k events are the minimum statistics.
• The macros are in directory  /adaqfs/home/adaq/xiaochao/analysis/pvdis/macro/
• Please copy macros you need to your own directory and run them there. Please do not run or edit them in their current directory.

• Basic timing, threshold and trigger checks (also the most important)
• Detailed timing check for PS and SH coincidence and VETO.
• PID analysis by Kai.
• How to increase slug# without flipping IHWP state.

Basic timing, threshold and trigger checks

• If we are in smooth production running, this is probablly the only timing check you need, twice a day or after each DAQ/cabling access work.
• The two basic macros to check timing are:
• plot_timing_left.cc and 
• plot_timing_right.cc 
• To execute, type 
• >analyzer [macroname]
• then follow prompt to enter run number and which group you want to plot. For each group, 7 plots will be generated. You may type 0 to skip one of them or -1 to exit from the macro.
• Sample histograms, from run 25363, group 4, are shown in the table below. This was a low current run. So if you use a high current (VDC off) run you may see significantly larger background in the electron trigger. You may want to check the following latest histograms for more samples.
• The latest plots for low current VDC on runs were made for run 5004 and 25452 using 200k events. Both runs were Q2 measurements:
• http://hallaweb.jlab.org/experiment/E05-007/meetings/production/run_5004
• http://hallaweb.jlab.org/experiment/E05-007/meetings/production/run_25452
• The latest plots for high current VDC off runs were made for run 5007 and 25455 using 200k events:
• http://hallaweb.jlab.org/experiment/E05-007/meetings/production/run_5007
• http://hallaweb.jlab.org/experiment/E05-007/meetings/production/run_25455 from this run you can see that all fbTDC histogram are very different from low rate running or right arm (also lower rate). A lot of these changes I still don't understand. In the global triggers you can see clearly pion contamination and electron-electron pile-ups. Both effects must be corrected when extracting asymmetries.

page 1, fbTDC of Left arm group 4:	What to watch for: All histograms on this page should be nice and narrow single-peaks. TSH and PSH should be aligned (same time) Electron narrow is earlier than electron wide by 10ns (20channels), and should have roughly the same shape. If there is clear cutoff on the right side of electron narrow, it indicates a late electron VETO, which causes event loss. Electron narrow and electron wide should have roughly the same # of events under the peak. Typically they do if there is no cutoff from the VETO. points 3 and 4 apply to pion triggers in the same way.   Note: on right arm they do not look as clean as left arm.
page 2, fbTDC of VETO, GC and T1, common for all groups	What to watch for? GC should be slightly earlier than T1. On both arms this timing difference have been tuned to 10ns. Too much below or above 10ns will cause either electron or pion VETOs to function incorrectly. GC&SC is the electron VETO. .not.GC & SC is the pion VETO. If you checked this for one group and it looks fine, then there is no need to plot this page for other groups (it's the same for all groups).
page 3: Cherenkov histogram for left arm group 4	What to watch for? Top center: this is after the electron VETO cut. You should see that the sharp peak near zero be largely suppressed. Otherwise the GC cut in the VETO circuit is not working Top right: this is after the pion VETO cut. You should see that ONLY the sharp peak near zero is here. Ideally, the sum of this and the top center plot gives you the total spectrum in the top left plot. Middle left: this is with GC only cut. Similar to #2, the sharp peak near zero should be largely suppressed. Otherwise the GC discriminator is not working Middle center, middle right and bottom left: These are after electron wide and narrow cuts of this group. Two TDC narrow cuts can be defined in the macro in case there are double peaks in EN trigger. Usually one of them is the main peak.  They should show only the electron peak away from zero;  The entry numbers of the MAIN trigger peak should be almost the same in narrow and wide paths.  bottom center and bottom right: These are after pion narrow and wide cut of this group. Contrary to electrons, they should ONLY have a sharp peak near zero. Also, the entry number should be similar in these two plots.
page 4: Preshower histogram for left arm group 4	What to watch for? Top right plot should show a clear cutoff compared to top left. The bottom two plots will have suppression of in the lower channels but the cutoff will not be as sharp as with the PSH cut (top right).
page 5: Preshower+Shower for left arm group 4	What to watch for? Top right plot should show a clear cutoff compared to top left.  Two different TSH cuts can be defined in the macro in case if the TSH fbTDC shows double peaks and if you want to take a closer look. Here they are defined as the same since there is no double peak (or I don't care about double peaks). For right arm this plot is for Preshower*2+Shower.
page 6: Preshower vs. Shower 2D plots for left arm group 4	What to watch for? the plot with TDC TSH cut should show a diagonal cut at channel 1200; the plot with TDC TSH cut should have a horizontal-line cut near 500; the plot with ENA and EWA cuts should have both the diagonal and horizontal cuts. And show nice electron distribution. (Note this plot currently have two ENA cuts. The 2nd one is the main trigger). The plot with PINA and PIWA cut should have a small diagonal cut. And the electron events should be largely suppressed. The last three plots show the hit position in PRL1. They should correspond to the blocks of this group. Each group should occupya different rectangular region of the focal plane. A hole coulde indicate missing lead glass block channel. Usually these should have already been checked during commissioning and should not have problem.  THese plots will be meaningful for VDC ON runs ONLY. For VDC off runs you will see only zero values.
page 7: PS vs SH 2D histogram for global electron and pion triggers Left arm run 25455 (high rate, VDC off) Right arm run 4921	What to watch for? The timing peak (top two) would not be as clean as single groups but should still be a single peak somewhat; The 2nd row shows L.prl1.asum_c vs. L.prl2.asum_c and L.cer.asum_c, without cut. The 3rd row shows L.prl1.asum_c vs. L.prl2.asum_c with cuts on fbTDC of the global EN and EW triggers. They should show a distinct electron "blob" and little events at low energies. The two plots should have roughly the same # of entries, with EW slightly higher than EN. The 4th row shows Cerenkov spectrom with EN and EW cuts. They should show the electron peak (large amplitude) and the peak near zero should be somewhat largely suppressed. This particular run, however, seems to have only a 1/100 suppression compared to the no-cut plot. Thresholds might need to be increased. The 5th row shows Cerenkov spectrum with pionN and pionW cut. They should show zero electron yield (large amplitude), and a sharp peak near zero since this is where pions are supposed to be. The right arm plot (here is run 4921), shows a much better PID behavior in electron spectrums.

Detailed timing check for PS and SH coincidence and VETO

• The macros are 
• plot_time_diff_left.cc and
• plot_time_diff_right.cc
• To execute, type 
• >analyzer [macroname]
• then follow prompt to enter run number, then wait for 2 pages of results to be plotted.
• Sample histograms, from run 25363 (and 25325), are shown in the table below. Histograms for various other runs are often copied to http://hallaweb.jlab.org/experiment/E05-007/meetings/production/, in case you want to see more samples.
• Some histograms from a test run in June 2009 can be found here:
• http://hallaweb.jlab.org/experiment/E05-007/meetings/testrun_may09/time_diff/run_22517/electron_ts-minus-ps.pdf
• this is a good example that we do not need to see a 0 (zero) difference in TS-PS fbTDC histogram. For this run, one can see that gr5-8 were aligned even though they are not centered at zero (the red histogram , or EN loss, is symmetric on the two sides). While gr1-4 are centered at zero but the signals are actually not aligned at the ANDing module because the red histogram is clearly asymmetric. The origin of the non-zero MEAN difference could come from different cable length when sending the signal from the discriminators to the ANDing module vs. to the NIM/ECL module. For production runs we have aligned all groups on the right arm in the same way as gr5-8.
• On the left arm, however, it is found that a zero difference in fbtDC TS-PS means they are aligned at the ANDing module, as can be seen from the plots below.

page 1, timing difference between PS and SH, left arm run 25363.

What do these mean? What you see here are fbTDC TS minus PS, 0.5ns per channel. Red shows events that do not trigger narrow electron path, and blue shows events that do not trigger wide electron path; In general, you will see both sides of the peak to be red, and the cutoff will be 120 channels, or 60ns wide. This is because the narrow path is 30ns wide and if the two signals miss each other by 60ns, they would not trigger narrow paths; In the plot on the left we also see small loss of both red and blue (here blue completely covers the red), in the middle of the peak. This could be because of loss due to Cherenkov cuts. But the loss should be very small. What to watch for? If the red (narrow loss) shows up only on one edge of the peak and cause a large loss, the timing of either PS or TS of that group should be adjusted.

page 2, timing between VETO and PS/TS signals, left arm Run 25363 Run 25325

What do these mean? What you see here are electron VETO minus the smaller value of PS and TS. Since smaller TDC reading means later signal, min(TS,PS) would be the starting edge of TS.and.PS that goes to the ANDing module. red and blue, again, shows events that do not trigger narrow and wide paths. If there is no loss from late VETOs, you should no see any red or blue. What to watch for? Any red or blue distribution would be a warning sign. For run 25325, for example, the VETO is too late by about 10ns (20 channels) for 4 out of 6 groups, as you can see from the plot on the left. This means we should add 12-16ns delay cables to PS and TS of all groups. We did this during one of the accesses, on Nov. 7 (?)

How to increase slug # without flipping IHWP

• as apar@adaql*, goto pvdis/runlist/DB
• change the # in the file SLUGNUMBER
• make a halog entry for what you did.