PARITY BEAM STUDIES 6092016 Caryn Palatchi BEAM CHARGE

PARITY BEAM STUDIES 6/09/2016 Caryn Palatchi

BEAM CHARGE ASYMMETRY Run Ge. V energy 2333 2358 2488 2494 2498 Run u. A current 4. 4 8. 8 energy 1905 ppm ppm dbcm 1 MHz Aq dbcm RMS ps=0 dbcm RMS notes 12 62. 64 493. 9 576. 4 IHWP out 13. 7 44. 7 309. 1 428. 6 IHWP out 60 30. 79 121. 9 326. 8 IHWP in 45 25. 37 117. 7 317 IHWP in 45 42. 7 116 314 IHWP in current 8. 8 Inj bcm Aq 60 injbcm RMS ps=0 Inj bcm RMS -0. 7 223. 9 IHWP in

BEAM ASYMMETRY WIDTHS • Higher energies don’t appear to bear much relationship to widths observed 1 MHz dbcm RMS, different energies 2. 2 -11 Ge. V 1 MHz dbcm RMS, different currents 12 -60 u. A 2500 30 Hz pairsynch[0]==0 2000 60 Hz 120 Hz (60 Hz filtered out) 1500 30 Hz pairsynch[0]==0 2000 RMS Aq (ppm) • Higher currents may generally tend to be associated with smaller widths 2. 4 k. Hz 1000 60 Hz 120 Hz (60 Hz filtered out) 1500 2. 4 k. Hz 1000 500 0 2 4 6 Energy(Ge. V) 8 10 12 0 20 40 Current(u. A) 60 80

BEAM ASYMMETRY WIDTHS INJECTOR Injector • Higher frequencies tend to result in smaller widths (scaled to counting statistics) Ge. V Run u. A Hz bcm 0 L 02 ppm/sqrt(Hz) energy current frequency RMS ps 0=0 bcm RMS Analysis with ADC subblocks of helicity window 1905 8. 8 60 30 1905 8. 8 60 60 Injector, 1905 multiple 1902 frequencies, 4 pass 1902 8. 8 60 120 8. 8 60 567 8. 8 60 1134 208. 1 normal 273. 1 (b 1+b 2 -b 3 -b 4)/(b 1+b 2+b 3+b 4) 212. 7 1/2((b 1 -b 2)/(b 1+b 2)+ (b 4 -b 3)/(b 3+b 4)), (60 Hz filtered out) 653. 6 (b 1+b 2 -b 3 -b 4)/(b 1+b 2+b 3+b 4) 531. 3 (b 1 -b 2)/(b 1+b 2) RMS/sqrt(f) 37. 99 35. 26 19. 42 27. 45 15. 81

di b ff_ pm bp 0 I 0 di m 0 1 ff_ I 0 1 b di pm A ff_ 1 b I 0 di pm 2 ff_ 1 b I 0 di pm 4 ff_ 1 di bp I 06 ff_ m bp 0 I 0 di m 0 2 ff_ I 0 2 b di pm A ff_ 0 I di bp 05 m ff_ bp 0 I 0 di 7 ff_ m 0 b L di pm 01 ff_ 0 b L di pm 02 ff_ 0 b L di pm 03 ff_ 0 b L di pm 04 ff_ 0 b L di pm 05 ff_ 0 b L di pm 06 ff_ 0 b L di pm 07 ff_ 0 b L di pm 08 ff_ 0 L di bpm 09 ff_ bp 0 L 1 di ff_ m 0 0 bp R 0 m 3 0 R 05 ff_ di diff_bpm (nm) NOW 30 Hz fliprate INJECTOR BEAM POSITION DIFFERENCES Injector X & Y position differences, 30 Hz, 8. 8 Ge. V, 60 u. A, Run 1905 250 200 150 100 50 0 -50 -100 -150 -200 -250 -300

BEAM POSITION DIFFERENCES 2010 120 Hz fliprate • PREXI Ref: Silwal Thesis, Fig. 6. 7. 5 INJECTOR

RMS diff_bpm (um)

BEAM POSITION DIFFERENCE WIDTHS Run 2347 2349 2333 2358 2494 2488 2434 Ge. V u. A Hz energy current frequency conditions 2. 2 4. 4 8. 8 11 18. 6 18. 7 12 13. 7 45 60 15 1/2((b 1 -b 2)/(b 1+b 2)+ (b 4120 Hz b 3)/(b 3+b 4)) (60 Hz filtered out) 11 15 2437 11 15 2370 Hz (b 1 -b 2)/(b 1+b 2), pairsynch=0 11 15 bpm 4 ax bpm 4 aybpm 4 bx bpm 4 by bpm 8 x bpm 8 y bpm 12 x bpm 12 y bpm 14 x bpm 14 y 30 Hz 6. 395* 14. 23* 30 Hz 6. 644* 12. 15* 30 Hz noisy run, ffb might not be on 9. 805* 17. 5* 30 Hz 10. 4* 34. 55* 30 Hz 11. 17* 24. 41* 30 Hz 7. 22* 23. 48* 30 Hz - 2434 RMS um RMS um RMS um (b 1 -b 2)/(b 1+b 2) , pairsynch=0, 120 Hz (60 Hz sensitive) 11. 91 9. 46 18. 53 8. 04 12. 41 10. 97 7. 48 14. 83 8. 87 7. 97 15. 87 8. 95 48. 84 9. 73 27. 14 10. 4 13. 27 30. 96 13. 34 15. 47 11. 05 13. 31 23. 34 7. 32 12. 27 10. 27* 28. 27* 21. 06 7. 12 11. 26 12. 91 10. 03 21. 27 9. 76 13. 39 8. 98. 0814. 5543. 8710. 15 4. 96 10. 41 6. 51 21. 99 6. 55 8. 55 9. 82 6. 97 13. 8 10. 14 4. 75 5. 58 25. 6 26. 72 17. 98 30. 14 6. 32 29. 39 - - 10. 45 10. 81 22. 87 6. 22 - - 26. 98 43. 32 - - 18. 66 16. 34 34. 27 36. 33 19. 4 66. 9 10. 34 15. 07 *filtered: evt_bpm 4 ax[0]<a&&evt_bpm 4 ax[1]<a

Not very dependent on number of passes 200 BEAM POSITION DIFFERENCES 1 pass 4 pass Hall. A X & Y position differences, 30 Hz, 2. 2 Ge. V, 19 u. A, Run 2349 Hall. A X & Y position differences, 30 Hz, 8. 8 Ge. V, 45 u. A, Run 2496 50 100 diff_bpm (nm) 150 50 0 -50 -100 -150 -200 -250 -300 diff_bpm 4 b diff_bpm 8 diff_bpm 12 RMS diff_bpm (um) diff_bpm 4 a filtered RMS diff_bpm (um) 0 16 14 12 10 8 6 4 2 0 diff_bpm 4 a filtered diff_bpm 4 b diff_bpm 8 diff_bpm 12 diff_bpm 14 26 24 22 20 18 16 14 12 10 8 6 4 2 0

PARITY QUALITY • Do we have it? We are in a good position to get it. • We already have small helicity correlated changes in Aq : ~30 ppm • What about the noise? Aq widths and bpm widths look similar to the past: 10’s of um • Increasing the flip rate will improve matters even further • How will small position differences be achieved? In the usual way: Pockels Cell centering, RHWP & photocathode rotation • Will we have it? Yes, with some small adjustments to the source alignment. • Is the beam usable? Yes. If the beam can be delivered to the hall, it is usable for parity experiments. • Are the monitors working? We have sufficient monitors currently operational to perform a parity experiment. We want to optimize the additional monitors. RHWP scan Ref: Silwal Thesis, Fig 6. 8 Ref: Silwal Thesis, Fig 6. 7. 2 PC centering Photocathode rotation

MONITOR TESTS

PITA SCAN Test • PITA scan functions as a test of the monitor linearity, test of the calibrations, and assesses the analyzing power of the photocathode • We performed a PITA scan at 30 Hz, 8. 8 Ge. V, 45 u. A, with IHWP in, LH 2 target in, and SAMs on • Range: +- 2000 counts (65535 counts/4000 V conversion factor) Results • 1 MHz dbcm indicates PITA slope of -38 ppm/V (+-2000 ppm measurement) • PREX I (2010), observed PITA slopes of 22 -31 ppm/V which corresponded to a photocathode analyzing power of ~6% (Ref: Silwal Thesis) • Suggests photocathode analyzing power of 8 -10% • Position Differences – go through 0, have slopes of ~0. 1 -1 nm/ppm • SAMs – slopes reveal non-linearity of up to several % for various HV settings

PITA SCAN • 1 MHz dbcm indicates PITA slope of -38 ppm/V (+-2000 ppm measurement, 65535 counts/4000 V conversion factor) ppm • Central value of Aq 30. 95 ppm 1 MHz dbcm ppm HV+ counts 1 MHz dbcm Aq=30. 95 ppm 13

BEAM CURRENT MONITORS

DIGITAL BCMS DELAY & LINEARITY • The 1 MHz system has a small ~10 us delay = 2. 5 us(latency)+7 -8 us(risetime) 15 • New digital receiver system has 3 outputs– ‘fast’/OPS, ‘adjustable’, ‘slow’/EPICS • Digital reciever slow’/EPICS output setting has a 5. 1 ms delay(measured with tune beam) due to low pass filters and additional latency • By changing the output mode to ‘fast’, removing many of the applied low-pass filters, we can reduce the delay to ~16 -18 us(relative to the 1 MHz system) and ~26 -28 us total delay relative to beam • We can further reduce the delay by bypassing several filters in ‘straight through’ mode, delay down to 1 us (relative to the 1 MHz system) and 11 us total delay =4. 5 us(latency)+ 6. 5(risetime) • Comparing both 1 MHz and digital reciever systems, we – we can adjust the gate delay on our ADCS by 0 us or 2 us and adjust the receiver gain to keep output below 10 V(our ADC limit) and we’ll be set. • New Mussons saturated at 40 u. A for a particular gain setting during running, but the gain settings were simply adjusted. We are going to put some attenuators on the receiver input and adjust the internal attenuators to make it physically impossible for any experiment to saturate the receivers in the future If we properly make use of the digital system settings, it looks nice and linear We can tailor digital filters applied to suit our needs This low-latency setting will work for us in PREXII

DBCM ‘SLOW’ 1 MHz dbcm tune beam 16 new dbcm ‘slow’

DBCM NO FILTER 1 MHz dbcm tune beam 17 new dbcm no filter

DBCM NO FILTER 1 MHz dbcm tune beam 18 new dbcm no filter

EVIDENCE LEADING UP TO BCM DELAY MEASUREMENT • There were many symptoms which indicates delay was happening with the digital receivers • It is important to make note of these symptoms so that we can diagnose delay in other signals • The evidence appeared as 1. Less correlation with other monitors, more uncorellated noise, wider DDs 2. 60 Hz signal (detected by beat oscillation between near 120 Hz subblock rep rate) showed phase delay relative to other signals 3. Earlier (sub-block) data points showed more correlation with other monitors than sameevent (sub-block) data points 4. Beam trips weren’t happening at the same event (or subblock event) as other signals 5. (Smaller PITA slopes)

BCM RESOLUTION • 1 MHz Bcm’s behave well most of the time and resolution looks good • Resolution of 1 MHz system improves with higher current and improves with higher frequency • Resolution can be assessed from double difference widths of upstream and downstream 1 MHz bcms • For 120 Hz, at 12 u. A, we have a resolution of ~43 ppm • For 30 Hz, at 60 u. A, we have a resolution of ~11 ppm • Resolution measurement can be independently checked using the SAMs • For 30 Hz, 20 u. A, we have a resolution of ~30 ppm • For 30 Hz, 45 u. A, we have a resolution of ~13 ppm This is sufficient bcm resolution for PREXII (>70 u. A, 120 Hz)

21 BCM 1 MHZ NOISE FROM SAMS Run 2347 – carbon 2. 2 Ge. V 18. 6 u. A 30 Hz , regress with 4 a, 4 b, 12 x regressed after reanalysis with pairsynch normal maxevent 5000 (asym_bcm 3 -asymbcm 4)/sqrt(2) reg_asym_n_blumi 1+reg_asym_n_blumi 5 reg_asym_n_blumi 1 -reg_asym_n_blumi 5 sqrt(pow(250. 2, 2)-pow(243. 8, 2))/2 - regress with all bpms except 14 reg_asym_n_blumi 1+reg_asym_n_blumi 5 reg_asym_n_blumi 1 -reg_asym_n_blumi 5 sqrt(pow(234. 7, 2)-pow(225. 2, 2))/2 RMS ppm 25. 1 250. 2 243. 8 28. 1 234. 7 225. 2 33. 0 Run 2503 – Al dummy 8. 8 Ge. V 45 u. A 30 Hz, regress with all bpms regressed after reanalysis with pairsynch normal maxevent 5000 (asym_bcm 3 -asymbcm 4)/sqrt(2) reg_asym_n_blumi 1+reg_asym_n_blumi 5 reg_asym_n_blumi 1 -reg_asym_n_blumi 5 sqrt(pow(98. 61, 2)-pow(95. 37, 2))/2 ppm 13. 1 98. 61 95. 37 12. 5

BCM 1 MHZ RESOLUTION 22 Wide because of P. C. 4 peak effect Jump because of noise later in run Current

BCM 1 MHZ RESOLUTION 23

BCM 1 MHZ RESOLUTION FREQUENCY Ge. V Run 2333 2 pass, 2333 multiple frequencies 2333 u. A Hz ubcm-dbcm energy current frequency DD RMS 4. 4 12 30 4. 4 12 60 4. 4 12 120 Analysis with ADC subblocks of helicity window 75. 0 37. 5 normal 93. 5 46. 75 (b 1+b 2 -b 3 -b 4)/(b 1+b 2+b 3+b 4) 85. 6 42. 8 1/2((b 1 -b 2)/(b 1+b 2)+ (b 4 -b 3)/(b 3+b 4)), (60 Hz filtered out) RMS/sqrt(f) 6. 85 6. 04 3. 91

SMALL ANGLE MONITORS

SAM ASYMMETRY WIDTHS 26

SAM LINEARITY 27 PITA SCAN Settings during PITA scan • LH 2 target, 45 u. A, 8. 8 Ge. V • Bases: SAM 1/3/5/7=R 7723, SAM 2/6=R 375&UNITY GAIN, SAM 4/8=R 375 • Preamps: SAM 1/5=100 k. Ohm, SAM 2/6=5 MOhm, SAM 3/7=36 k. Ohm, SAM 4/8=300 k. Ohm • HVs: SAM 1/5=600 V, SAM 2/6=75 V, SAM 3/7=700 V, SAM 4/8=350 V • Layout: SAM 1=TOP, SAM 2=TR, SAM 3=RIGHT, SAM 4=BR, SAM 5=B, SAM 6=BL, SAM 7=L, SAM 8=TL • Pedestals: calculated from beam trips during PITA scan Analysis • Because SAMs are also sensitive to position differences, must use regression with respect to bpms to get best estimate of actual SAM non-linearity • Lower slopes than bcm indicate either pedestal error, SAM saturation • Higher slopes than bcm indicate either pedestal error or nonlinearity

SAM 1 SAM 5 SAM 2 SAM 6 SAM 3 SAM 7 SAM 4 SAM 8

SAM LINEARITY PITA SCAN Rate 1. 3 -2 GHz PITA Slope d. Aq/d. PITA from dbcm Max error on PITA slope meas (%) SAM base type HV setting (V) anode current (u. A) gains estimate Max pedestal error(%) SAM PITA slopes d. Asam/d. PITA d(Asam-Aq)/d. PITA d(regressed (Asam-Aq))/d. PITA SAM implied nonlinearity (%) from d. Asam/d. PITA from d(Asam-Aq)/d. PITA from d(regressed (Asam-Aq))/d. PITA factoring out max sam ped errors MINIUMU NON LINEARITY (%) (factoring out max PITA slp error) • Put bound on sam nonlinearity, factoring in the possible error in PITA slope measurement from bcms and possible pedestal error of dbcm 1 MHz ubcm 1 MHz -2. 3156 ppm/V -2. 34356 ppm/V SAMs 1. 21% SAM 1 R 7723 SAM 5 R 7723 • Assume max pedestal error of 100 ch on SAMs (from beam trip decay) SAM 2 R 375 SAM 6 R 375 SAM 3 R 7723 SAM 7 R 7723 SAM 4 R 375 SAM 8 R 375 -600 V -75 V -700 V -350 V 27. 7 u. A 36. 0 u. A 0. 0011 u. A 0. 0016 u. A 73. 6 u. A 55. 7 u. A 8. 6 u. A 11. 6 u. A 2. 08 E+04 2. 71 E+04 1 1 5. 53 E+04 4. 18 E+04 6. 43 E+03 8. 73 E+03 0. 28% 0. 21% 14. 38% 9. 54% 0. 29% 0. 38% 0. 30% 0. 22% SAM 1(PITA slp) SAM 5(PITA slp) SAM 2(PITA slp) SAM 6(PITA slp) SAM 3(PITA slp) SAM 7(PITA slp) SAM 4(PITA slp) SAM 8(PITA slp) -2. 31111 ppm/V -2. 32939 ppm/V -2. 32183 ppm/V -2. 31818 ppm/V -2. 41158 ppm/V -2. 3687 ppm/V -2. 43821 ppm/V -2. 47723 ppm/V 0. 00425 ppm/V -0. 014 ppm/V -0. 00304 ppm/V -0. 0029 ppm/V -0. 096 ppm/V -0. 053 ppm/V -0. 123 ppm/V -0. 162 ppm/V 0. 00272 ppm/V -0. 00752 ppm/V -0. 01866 ppm/V 0. 01980 ppm/V -0. 10737 ppm/V -0. 0161 ppm/V -0. 12680 ppm/V -0. 11845 ppm/V SAM 1(nonlin) SAM 5(nonlin) SAM 2(nonlin) SAM 6(nonlin) SAM 3(nonlin) SAM 7( nonlin) SAM 4(nonlin) SAM 8(nonlin) -0. 20% 0. 59% 0. 27% 0. 11% 4. 14% 2. 29% 5. 29% 6. 98% -0. 43% 1. 40% 0. 30% 0. 29% 9. 60% 5. 30% 12. 30% 16. 20% -0. 27% 0. 75% 1. 87% -1. 98% 10. 74% 1. 61% 12. 68% 11. 85% 0. 00% 0. 54% 0% 0% 10. 45% 1. 23% 12. 38% 11. 63% 0% 0% 9. 24% 0. 02% 11. 18% 10. 42%

SAM LINEARITY PITA SCAN Results • The high gain SAMs with the R 375 bases show a positive non-linearity of • >10% (when run at 350 V, 10 u. A anode current, gain~7 k) • The unity gain SAMs have a non-linearity of • 0%(<1. 5% )(when run at 75 V, 1 -2 n. A anode current, 1. 3 -2 GHz rates) • The high gain R 7723 base SAMs have a positive non-linearity of • 0 -1% (when run at 600 -700 V, 26 -36 u. A, gain~25 k) • 0. 02 -2%(when run at 700 V, 56 u. A anode current, gain ~42 k) • 10% (when run at 700 V, 74 u. A anode current, gain ~55 k)

BEAM POSITION MONITORS

BPM STATUS • Previously had an auto gaining issue near 20 u. A, there was a transition in gain setting near that current region producing 1 V square waves in the wire channel signal every second or so. The settings were changed, and the problem was solved. • Now we have a very small jumping issue (50 m. V jumps in x wire channels every couple seconds) which is not always present (went away in 4 a and showed in in 4 b for 60 u. A) and is likely also caused by some sort of internal setting • Pete Francis going replace IF modules during summer, so this may go away after that • If the 50 m. V wire channel shifts are still present in the RF injected noise tests after IF modules are replaced, then need to examine internal settings, how IF gain and gain interplay with FFB, etc. • Musson cavity bpms– being commissioned