081017
PMTs have been on probably all summer.
PMT HV. Movable = 2200. Fixed = 2300
PMTS positioned at back of cradles. 72cm from NaI face to NaI face.
CF Discs setup to only cut out first few channels of noise. No attempt to bracket 511keV peak.
Gross counts of entire PHA spectrum of fixed dynode gated by CF disc. 300s run.
Movable = 534768
Fixed = 757907
Singles rates from CF discs (10s run).
Movable = 1857.7hz
Fixed = 1701.3hz
Time Calibration. Measured from 50% falling edge.
| Delay Setting | Measured Delay | PHA Ch |
| 12 | 18 +/- .4 | 38 +/- 1 |
| 16 | 21.8 | 122 |
| 24 | 29.8 | 299 |
| 32 | 38 | 471 |
| 40 | 46 +/- .8 | 650 |
| 48 | 54 | 822 |
| 56 | 62 | 998 |
Use 32ns for the delay setting.
Fitting the data to a straight line yields a conversion factor of
t(ns) = 16.2 + 0.05 * Ch
{
${/download/attachments/164083740/Timing_calib.png?version=1&modificationDate=1502976866000&api=v2}$
Since timing calibration was done using one pmt signal, test for time delay between fixed and movable channels. Swap the outputs from the CF discs between TAC start and stop.
Movable-start, Fixed-stop. Centroid = 784 ( 55.4ns )
Fixed-start, Movable-stop. Centroid = 374 ( 34.9ns )
081117
Created two ROI's. One over full spectrum (CH x to y ) and the other over the symmetric part of the coincidence peak ( CH x to y ). Recorded gross counts for both selections. Also recorded coincidence peak centroid for shits and giggles. 5 minute runs.
| Pos (cm) ± 0.02 | X | Y | Pos (cm) | Z |
| 0 | Full = 868 Peak = 472 Centroid = 778 | 855 404 779.4 | 0 | 761 387 781 |
| 1 | 905 466 778.6 | 915 498 779.3 | .1 | 750 364 779.4 |
| 2 | 1026 533 777.4 | 995 525 778.8 | 2 | 826 441 779.9 |
| 3 | 1075 596 777.8 | 1037 557 780.4 | 3 | 820 458 780.6 |
| 4 | 1207 663 779.2 | 1202 655 778.3 | 4 | 880 455 779.8 |
| 5 | 6179 3992 777.5 | 6594 4293 778.9 | 5 | 875 480 781.1 |
| 6 | 42017 31552 778.1 | 37863 28142 780.9 | 6 | 907 491 780.4 |
| 7 | 84178 65026 778.3 | 78521 60847 781.3 | 7 | 974 522 781.7 |
| 8 | 68834 53010 778.4 | 69859 53865 781.6 | 8 | 1031 591 780.5 |
| 9 | 25532 18600 779.0 | 27880 20383 781.8 | 9 | 1112 620 779.2 |
| 10 | 7170 4602 780.5 | 6078 3828 777.9 | 10 | 1159 654 780.7 |
| 11 | 20495 15156 782.5 | 20216 15000 776.8 | 11 | 2214 1337 778.7 |
| 12 | 31875 24401 783.1 | 34526 26396 776.7 | 12 | 11703 8327 780.4 |
| 13 | 22552 16925 783.3 | 26957 20410 777.1 | 13 | 37452 28564 780.9 |
| 14 | 7115 4814 781.8 | 9655 6750 777.5 | 14 | 68197 53770 781.1 |
| 15 | 1429 832 779.8 | 1722 1032 779.3 | 15 | 88732 70836 781.1 |
| 16 | 1004 567 779.4 | 1053 569 777.9 | 16 | 64280 50835 781.4 |
| 17 | 918 501 779.1 | 985 513 779.1 | 17 | 33045 25238 781.4 |
| 18 | 865 430 780.0 | 951 506 778.1 | 18 | 9805 6776 781.7 |
| 19 | 2421 1470 781.7 | |||
| 20 | 1356 763 781.1 | |||
| 21 | 2280 1410 780.6 | |||
| 22 | 9277 6720 780.5 | |||
| 23 | 20887 15989 781.0 | |||
| 24 | 31551 24791 781.0 | |||
| 25 | 32195 25308 781.4 | |||
| 26 | 22427 17535 781.4 | |||
| 27 | 10188 7406 781.6 | |||
| 28 | 2610 1573 780.9 | |||
| 29 | 1008 545 781.5 | |||
| 30 | 955 531 779.5 | |||
| 31 | 989 536 781.3 | |||
| 32 | 895 502 781.5 | |||
| 33 | 861 460 781.5 |
081517
Measure the spatial resolution of the detector. Source is translated through the fov of the two detectors. Scale position is measured relative to the edge of the source platform.
300s runs. Top number is gross counts over full spectrum, bottom number is gross counts in roi of peak.
| Scale position (cm) | Coinc Counts |
| 18 | 427 274 |
| 19 | 464 299 |
| 20 | 640 397 |
| 21 | 1972 1343 |
| 21.5 | 4013 2850 |
| 22 | 5777 4291 |
| 22.5 | 6972 5218 |
| 23 | 6080 4547 |
| 23.5 | 4107 2993 |
| 24 | 1954 1296 |
| 25 | 623 776 |
| 26 | 456 290 |
Fit the data to a gaussian of the form
{ ${/download/attachments/164083740/image2017-8-17%209%3A17%3A56.png?version=1&modificationDate=1502979476000&api=v2}$
Full Spectrum : a0 = 460, a1 = 14517, a2 = 0.9, a3 = 22.5
Coinc Peak : a0 = 323, a1 = 10594, a2 = 0.9, a3 = 22.5
{ ${/download/attachments/164083740/Spatial_res.png?version=1&modificationDate=1502978980000&api=v2}$
Conclusion: We can resolve location along the x-axis to within 1cm. Integrating over the full TAC spectrum yields just as good result as integrating only over the coincident peak.
Measure TOF resolution. Keep source on midline between detectors.
| Location | Centroid * Counts in 600s | Centroid Counts in 600s |
| -35.6 | 834 11722 | 840 25479 |
| -14 | 794 4507 | 802 43222 |
| 0 | 779 13248 | 779.7 66741 |
| 14 | 757 23347 | 758.5 43503 |
| 34.3 | 705 18431 | 695 40906 |
| Retook data with source centered vertically wrt pmt's. |
| Y Loc (cm) | Centroid Gross Counts full Spectrum (300s) |
| 35 | 701 27544 |
| 30 | 729 19462 |
| 20 | 748 23282 |
| 10 | 763 32965 |
| 0 | 780 40046 |
| -10 | 796 29668 |
| -20 | 811 21440 |
| -30 | 829 16898 |
| -35 | 840 17429 |
The data point at 35cm, up against the movable pmt, has some systematic issue. Omitting it allows for a nice linear fit to the data yielding:
TOF = 52.1ns - 0.077 ns/cm * Y
{ ${/download/attachments/164083740/Temporal_res.png?version=1&modificationDate=1502985296000&api=v2}$
081717
Retake scan data. PMT's have been running continuously. Recentered pmts in their holders. Try 2 min runs to reduce time needed to take data. Take counts in full spectrum. Fixed pmt is start, movable is stop.
| X-Y Position | X Counts Centroid | Y Counts Centroid | Z Position |
| 1 | 321 780.5 | 334 780.5 | 747 779 |
| 2 | 361 770.2 | 381 775 | 736 776 |
| 3 | 390 778 | 397 780 | 815 776 |
| 4 | 420 783 | 424 778 | 858 780 |
| 5 | 1941 776 | 2968 784 | 1033 779 |
| 6 | 14433 778 | 16010 784 | 1131 778 |
| 7 | 30932 778 | 30552 784.5 | 2553 779 |
| 8 | 28438 778 | 25379 784 | 39224 781 |
| 9 | 9215 781 | 8098 784.5 | 89704 783 |
| 10 | 3054 785 | 2982 778 | 42004 784 |
| 11 | 9085 786 | 9172 777.7 | 2981 779 |
| 12 | 12953 786 | 13541 777 | 1229 780 |
| 13 | 8032 786 | 8667 777.1 | 1058 779 |
| 14 | 2254 783 | 2558 781 | 869 778 |
| 15 | 481 779 | 563 779 | 841 777 |
| 16 | 395 782 | 384 778 | 794 773 |
| 17 | 350 778 | 379 785 |
082217
Made new markings on source box. Marks are now 2cm apart along X and Y. Retake data. 300s runs.
| Position | X Counts Centroid | Y Counts Centroid | Z Position |
| 1 | 909 771 | 932 777 | 747 779 |
| 2 | 980 772 | 1338 773 | 736 776 |
| 3 | 7134 778 | 25749 776 | 815 776 |
| 4 | 76471 783 | 21232 777 | 858 780 |
| 5 | 25378 783 | 29571 783 | 1033 779 |
| 6 | 20647 777 | 78152 784 | 1131 778 |
| 7 | 25568 777 | 5795 780 | 2553 779 |
| 8 | 1406 776 | 1093 777 | 39224 781 |
| 9 | 919 778 | 892 781 | 89704 783 |
| 10 | |||
| 42004 784 | |||
| 11 | |||
| 2981 779 | |||
| 12 | |||
| 1229 780 | |||
| 13 | |||
| 1058 779 | |||
| 14 | |||
| 869 778 | |||
| 15 | |||
| 841 777 | |||
| 16 | |||
| 794 773 | |||
| 17 | |||
| 724 772 |
Reconstruction using only X and Y slices.
{ ${/download/attachments/164083740/image2018-3-8_9-33-21.png?version=1&modificationDate=1520523201000&api=v2}$
Reconstruction using X, Y, and Z slices
{ ${/download/attachments/164083740/image2018-3-8_9-33-38.png?version=1&modificationDate=1520523218000&api=v2}$