CHESS-U Sextupole Studies

This page serves to catalog and archive results of studies using the sextupole magnets in the CHESS-U ring. Machine studies shifts are documented here, including procedures for measuring phase functions, orbits, tunes as functions of sextupole settings.

Of particular interest is the possibility to measure the beam size in sextupoles. The basic idea is that sextupole offsets introduce a quadrupole error via the first derivative of the field, so the tune shift can be used to measure the offset. Then the second derivative provides a dipole error which depends on the summed squares of the offset and the beam size, so the tune shift can be used to isolate the beam size. A discussion of the derivation of the relationship between the beam size and the tune and orbit changes, including a test using the CHESSU lattice, can be found here). A Mathematica notebook showing derivations is available here).

An additional benefit of these studies is obtaining calibration constants (sextupole field strength versus current setting) and position offsets of the sextupole magnets relative to the design orbit.

The studies also include investigations into the measurement accuracy for the phase functions, orbits, and betatron tune values obtained via various methods, in particular comparing the Digital Tune Tracker to analysis of turn-by-turn data.

J.A. Crittenden, W. Carbonell, K. Deitrick, H. Duan, A. Fagan, G. Hoffstaetter, V. Khachatryan, I. Mishra, D. Sagan, A. Shaked, and S. Wang / 27 February 2024

Machine Studies

txt

pdf

Saturday 26 March 2024 (18h00-20h00) (csr saveset 170913)
Elog entry (Phase files 32998-32996)
Obtained BPM/quad offsets for 35W and all available south arc BPMs. Missing south arc BPMs are X5D, X3B, X4C and X4D.
Performed the Shanks test: set quad by hand and take 10 phase measurements at each of the two settings. Recalibrate all pairs.
Obtained 24 measurements for 32E, which has beta values very different from those at 18E.
Saturday 19 March 2024 (18h00-20h00) (csr saveset 170821)
Elog entry (Phase files 32856-32996)
Repeatability study for BPM/quad offset measurements, following up on 2 March 2024.
Obtained 53 measurements of BPM/quad offsets for BPM 18E for dQ_max_quad_calib = 0.02 (+- 4 kHz).
Obtained 9 measurements of BPM/quad offsets for BPM 18E for dQ_max_quad_calib = 0.03(+- 6 kHz).
Saturday 5 March 2024 (20h00-22h00) (csr saveset 170647)
Elog entry (Phase files 32794-32849)
Obtained two K2 scan data sets for 26W following lift/place/survey exercise in the morning. Nine settings in 6k steps, 3 phase measurements at each setting.
Used CesrV scripts k2scan_9settings_6k.cesrv.
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Saturday 2 March 2024 (08h00-13h00)
Elog entry (Phase files 32595-32761)
Measured the quad/bpm offsets for the north arc BPMs 16w, 31w, 33w, 18e.
Repeatability study using 18e discovered a systematic "walking" of the offset calculation with successive measurements, requiring CesrV code fix.
Wednesday 28 February 2024 (16h00-20h00) (csr saveset 170494)
Elog entry (Phase files 32251-32535)
Measured the quad/bpm offsets for the north arc BPMs, except for 10aw, 13w, 22w, 38w, 45w, 44e, 34e, 21
The study of repeatability of the quad/BPM offset measurements on 2 March 2024
discovered that when multiple calibrations are done for a BPM, the results for the offsets are
not repeated, but instead "walk" by a fixed interval accurate to about 10 microns.
So only the first measurement is valid. That error apples to the measurements recorded
during this shift as well. Therefore only the first measurement for the six BPMs for which
two measurements were made should be used in the offset.bpm file.
These are 46, 62, 68, 74, 79, 86, i.e. 46W, 37E, 31E, 25E, 20E, 13E.
The file /nfs/cesr/online/machine_data/meas/offset.bpm updated at 10:19 on 3 March 2024.
Tuesday 20 February 2024 (17h30-19h30) (csr saveset 170391)
Elog entry (Phase files 32070-32199)
Obtained K2 scan data for 26W, 10AE, 47E. Nine settings in 6k steps, 3 phase measurements at each setting.
Obtained K2 scan data for 34W. Nine settings in 3k steps, 3 phase measurements at each setting.
Used CesrV scripts k2scan_9settings_6k.cesrv, k2scan_9settings_3k.cesrv
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Friday 6 October 2023 (1530-21h30) (csr saveset 168979)
Elog entry (Phase files 31584-31780)
Created lattice file model_cesr_31588_1840808_with_xyoffsets_digested.dat and model 376 for use in the calibration data-taking to set the local bumps at the sextupoles.
Obtained calibration data for 32W, 45E, 25E, 18E and 09AE in these conditions.
Obtained K2 scan data for 32W, 45E, 25E, 09AE. Nine settings in 6k steps, 3 phase measurements at each setting.
Obtained K2 scan data for 32W, 45E, 25E, 09AE. Five settings in 6k steps, 3 phase measurements at each setting.
Obtained K2 scan data for 32W. Five settings in 6k steps, 1 phase measurement at each setting.
Used CesrV scripts model_cesr_with_xyoffsets.cesrv, calsex_loop.cesrv, k2scan_9settings_6k.cesrv, k2scan_5settings_6k.cesrv, k2scan_5settings_6k_1p.cesrv
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Thursday 5 October 2023 (1030-16h00)
Elog entry
Performed fine tune scan across sextupole resonance lines:
3Qy=2
Qx+2Qy+Qs
Qx+2Qy
for the sextupole calibration constants now in use in operations, which are calculated using the JAC calibration correction factors of 16 April 2023 inverted.
Then we began to repeat the scans for the calibration constants as calculated by JAC on 16 April without inverting the correction factors.
We restored the sextupole settings and xquening coefficients from 16 April and restored the chromaticity values to those in operations.
We managed to complete scans for 3Qy=2, Qx+2Qy+QS, and half of Qx+2Qy before losing linac operations.
No significant difference in the widths of the resonance lines was found.
Wednesday 4 October 2023 (10h00 - 16h30) (csr savesets 168922 and 168923)
Elog entry (Phase files 31272-31569)
Recorded K2 scan data for 26W 42W 34W 43W 44W 43E 18E 16E for which gain calibrations were done on 2 October 2023.
Condx 168922.
9 K2 settings in 6k cu steps with 3 phase files per setting.
K2 settings were scanned in both directions to test for hysteresis effects.
Bumped the beam horizontally to the centers of 18E and 16E and retook the K2 scan data in both directions.
Condx 168923.
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Monday 2 October 2023 (1030-16h00)
Elog entry
Made CESR model 375 with phase 31263 and orbit 1840086.
Took calibration data for 26W 42W 34W 44W 43W 43E for which BPM gain calibrations and quad centering were done earlier today.
Also took calibration data for 18E and 16E. Condx 168885.
Studied horizontal centering of 34W.
Took calibration data with orbits in condx 168886/7/8.
Used CesrV scripts model_cesr_with_xyoffsets.cesrv, calsex_loop.cesrv
Sunday 1 October 2023 (16h0-21h30) (csr saveset 168865)
Elog entry (Phase files 31072-31225)
Took K2 scan data for 26W, which was measured to have an anomalously large offset in 2021,
and for 35W, 36W, 18E, 16E which had gain calibrations measured yesterday, 30 September.
Condx 168865. phase is 31075, orbit 1839984.
Made CESR model 373 with phase 31075 and orbit 1839984. Took calibration data for these five sextupoles and for 24E. Mistakenly thought 24E processor had been swapped. Actually 25E had been swapped on 9/30.
Used CesrV scripts model_cesr_with_xyoffsets.cesrv, calsex_loop.cesrv, k2scan_9settings_6k.cesrv, k2scan_9settings_3k.cesrv, k2scan_9settings_500.cesrv,
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Monday 29 May 2023 (0800-12h30) (csr saveset 168628 (sextupole centering) and 168237 (27 May condx) with shaker amplitude settings H/V 462/151 (-26.7/-36.4 dB) )
Elog entry (Phase files 30903-30951)
Created lattice file model_cesr_30905_1811149_with_xyoffsets_digested.dat and model 368 for use in the calibration data-taking to set the local bumps at the sextupoles with improved centering in sextupoles 16E, 17E and 18E.
Obtained calibration data for 16E, 17E, 18E in these conditions.
Obtained K2 scan data for 16E, 17E, 18E in 27 May conditions. Five settings, 3 phase measurements at each setting.
Also obtained calibration data for 16E, 17E, 18E in these conditions.
Used CesrV scripts sextcenter.cesrv, model_cesr_with_xyoffsets.cesrv, calsex_loop.cesrv,k2scan_5settings_6k.cesrv
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Saturday 27 May 2023 (21h45-1h30) (csr saveset 167581 (Ops orbit) with shaker amplitude settings H/V 462/151 (-26.7/-36.4 dB) )
Elog entry (Phase files 30810-30898)
Save set csr 168237 (injection orbit, tunes H/V 222/243 kHz) used for both K2 scans and calibrations. Orbit 1311115.
Created lattice file model_cesr_30810_1811115_with_xyoffsets_digested.dat and model 367 for use in the calibration data-taking to set the local bumps at the sextupoles.
Obtained K2 scan data for 16E, 17E, 18E. Nine settings, 3 phase measurements at each setting.
Obtained calibration data for 16E, 17E, 18E.
Used CesrV scripts model_cesr_with_xyoffsets.cesrv, calsex_loop.cesrv,k2scan_9settings_6k.cesrv
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Sunday 16 April 2023 (12h00-16h00)
Elog entry
Scanned resonance lines in the tune plane for four sets of sextupole calibration constants:
1) the set now active for CHESS operations, installed on January 12 (see below),
2) the set in use prior to January, which was basically two numbers based on A.Mikailichenko field measurements and modeling in 1996 and 1998 (see tech notes below),
3) the most recent set including the 2023 measurements,
4) the latter values but with the correction factors inverted as was done in January.
Clear results for a variety of resonance lines observing beam lifetime while scanning the tunes.
Lines observed to be wider for set 2) than for the three others, but no clear differences between those three were obvious.
Installed set 4) for operations, since it is most similar to those in use up to now and has some improvments in accuracy.
A presentation on these and other studies is available here.
Friday 14 April 2023 (18h30-1h00) (csr saveset 167581 (Flat orbit with relevant sextupoles centered) with shaker amplitude settings H/V 490/140 (-26.2/-37.1 dB) )
Elog entry (Phase files 30580-30641)
Save sets csr 167512 (injection orbit, tunes H/V 222/243 kHz) for injection and 167518 (flat orbit, tunes H/V 224/241 kHz) for calibration data.
Created orbit 1769755 centered in the sextupoles to be calibrated.
Created lattice file model_cesr_30581_1769775_with_xyoffsets.dat and model 363 for use in the calibration data-taking to set the local bumps at the sextupoles.
Obtained K2 scan data for stray field test 35W, 36W, 40W, 42W after braiding power leads earlier in the day.
Obtained calibration data for 35W, 36W, 40W, 42W and 33W.
Recorded calibration data for 16E and 17E as well, but missing/non-gain-calibrated BPMs likely render the data too poor to use.
Used CesrV scripts sextcenter.cesrv, model_cesr_with_xyoffsets.cesrv, calsex_loop.cesrv,k2scan_5settings_6k.cesrv
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Thursday 13 April 2023 (20h00-1h00) (csr saveset 167467 (Flat orbit with relevant sextupoles centered) with shaker amplitude settings H/V 490/140 (-26.2/-37.1 dB) )
Elog entry (Phase files 30477-30579)
Save sets csr 167467 (injection orbit, tunes H/V 215/241 kHz) for injection and 167476 (flat orbit, tunes H/V 224/241 kHz) for calibration data.
Created orbit 1769040 centered in the sextupoles to be calibrated.
Created lattice file model_cesr_30480_1769040_with_xyoffsets.dat and model 362 for use in the calibration data-taking to set the local bumps at the sextupoles.
Obtained K2 scan data for stray field test 35W, 36W, 40W, 42W. The power leads were braided the following morning prior to the shift on 14 April 2023.
Also obtained K2 scan data for 32W, 33W.
Obtained calibration data sets for 32W, 33W, 35W, 36W, 40W, 42W.
Used CesrV scripts sextcenter.cesrv, model_cesr_with_xyoffsets.cesrv, calsex_loop.cesrv,k2scan_5settings_6k.cesrv
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Sunday 14 March 2023 (18h00-22h00) (csr saveset 167260 (Flat orbit) with shaker amplitude settings H/V 490/140 (-26.2/-37.1 dB) )
Elog entry (Phase files 30436-30438)
Save sets csr 167255 (injection orbit, tunes H/V 215/249 kHz) for injection and 167260 (flat orbit, tunes H/V 224/253 kHz) for calibration data.
Created orbit 1753143 centered in the sextupoles to be calibrated.
Created lattice file model_cesr_30437_1753143_with_xyoffsets.dat and model 353 for use in the calibration data-taking to set the local bumps at the sextupoles.
Obtained multiple calibration data sets for 45E, 26E, 34E, 12E, 16E, 37W, 19E, 38W, 10AE with varying sextupole k2 range settings and averaging.
Used CesrV scripts sextcenter.cesrv, model_cesr_with_xyoffsets.cesrv, calsex_loop.cesrv
Tune measurements with DTT data (txt (dt=2s), gif)
Sunday 7 March 2023 (16h00-22h00) (csr saveset 167193 (Flat orbit) with shaker amplitude settings H/V 490/143 (-26.2/-36.9 dB) )
Elog entry (Phase files 30349-30430)
Save sets csr 167104 (injection orbit, tunes H/V 215/249 kHz) for injection and 167193 (flat orbit, tunes H/V 224/252 kHz) for K2 scan and calibration data.
Obtained calibration and K2 scan data for 45E, 26E, 34E, 12E
Used CesrV scripts calsex_loop.cesrv, k2scan_5settings_6k.cesrv
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Sunday 26 February 2023 (10h00-20h00) (csr saveset 167087 (Flat orbit) with shaker amplitude settings H/V 490/140 (-26.2/-37.1 dB) )
Elog entry (Phase files 29986-30317)
Save sets csr 167083 (injection orbit, tunes H/V 215/249 kHz) for injection and 167087 (flat orbit, tunes H/V 218/253 kHz) for K2 scan and calibration data.
Obtained calibration data for 16W, 45E, 11E (no prior data),
9AW, 16W, 21W, 19E, 16E (new BPM processors),
12E, 09AE, 40W, 36W, 28W, 37W, 38W (existing data have large errors).
Obtained K2 scan data for 18E, 39E (no prior data),
9AW, 16W, 21W, 19E, 16E (new BPM processors),
26E, 22E, 41E, 37E, 31E, 41E, 37E, 10AE (existing data have large errors).
Used sextupole-centered orbit (phase 167087).
Used CesrV scripts sextcenter.cesrv,calsex_loop.cesrv, k2scan_9settings_6k.cesrv, k2scan_5settings_6k.cesrv.
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Friday 24 February 2023 (17h00-01h00) (csr saveset 167046 (Flat orbit) with shaker amplitude settings H/V 490/140 (-26.2/-37.1 dB) )
Elog entry (Phase files 29736-29976)
Save sets csr 167032 (injection orbit, tunes H/V 215/2249 kHz) for injection and 167046 (flat orbit, tunes H/V 220/249 kHz) for K2 scan data.
Obtained sextupole strength scan data for 18E (existing data poor quality and newly installed BPM processor), 39E (existing data poor),
and 9aw, 16W, 21W 19E 16E (completing all cases of newly installed BPM processors).
18E, 39E, 9AW, 16W, 21W: 9 settings between +-24k cu
19E, 16E 5 settings betwen +-12k cu.
Used CesrV scripts hvcorr_with_coupling.cesrv, k2scan_9settings_6k.cesrv, k2scan_5settings_6k.cesrv k2scan_9settings_6k.cesrv.
Tune measurements with TBT data (tunes: txt, gif, resolutions: gif)
Tune measurements with DTT data (txt (dt=2s), gif)
Thursday 12 January 2023 (15h00-20h00)
Elog entry (Phase files 29538 - 29545)
Studied loading the sextupole calibration correction factors obtained over the course of the eight shifts from January to May 2022.
These are produced by the PAW macro SEXTCALFIT.KUMAC and were presented in the contribution to the proceedings of IPAC22.
First looked at correcting only the polarity of S09AE, since it is in a sensitive position at the entrance of the south arc.
It's polarity was reversed by changing the k2_polarity(91) value in sextupole.cal. While the signs of the DK2DCU values in the lattice file,
the k2_polarity values are applied when the sextupole is set, based on the wiring at the sextupole. Only a few are negative.
Injection tuning after the reversal did not produce any significant improvement in the injection efficiency, nor in the measured chromaticity values.
We then loaded all of the new calibrations into sextupole.cal, removing the k2_polarity change since the constant for 09ae is negative.
All the others are within 10-20% of unity. This had quite a big effect on chromaticity, orbit and phase. However, the intention that they bring the H and V chromaticity values closer to the design values of +1 was foiled, in fact the H chromaticity value went up over +5.
Surmising (without particular justification) that the inverse changes should be used, we loaded those and obtained chromaticities much closer to +1.
Upon retuning injection, the beam appeared to be more stable at low current. Injection efficiency was at least as high as previously.
These conditions were reproducible after de-hysterizing the magnets. We filled easily to 100 mA with modest increases in H chromaticity to stabilize the beam at currents >60 mA. Operations overnight in these conditions were stable.
Tuesday 10 May 2022 (16h00-20h00) (csr saveset 164705 (Flat orbit) with shaker amplitude settings H/V 490/143 (-26.2/-36.9 dB) )
Elog entry (Phase files 29371 (H/V tunes 222/250 kHz), 29371-29393)
Ran the CesrV script calsex_loop.cesrv to record the calibration data.
Used model 322 with phase and coupling optimized to phase file 29371, but using a zero orbit as opposed to the measured "flat" orbit (1658762).
Used a variety of DTT averaging. Recorded phase measurements and TBT data for selected sextupoles.
Obtained calibration and offset data for sextupoles 10aw, 16w, 33w, 34w, 38w, 45e, 42e, 39e and 10ae
Tune measurements with DTT data (txt (dt=2s),gif)
Tuesday 26 April 2022 (18h00-20h00) (csr saveset 164558 (CHESS ops orbit) with shaker amplitude settings H/V 1462/327 for the first 41E calibration, 1462/197 thereafter)
Elog entry (Phase files 29341 (H/V tunes 221/251 kHz), 29337-29351)
Ran the CesrV script calsex_loop.cesrv to record the calibration data.
Used model 310 optimized to phase file 29341. Used average of 16 DTT readings and recorded a phase file for each setting.
Obtained calibration data for sextupoles 41E (twice, averaged 4 DTT readings per setting), 12E (averaged 16 DTT readings, phase files 29342-29351),
and 13E (averaged 4 DTT readings). The tunes used in the average were recorded to disk at 1-second intervals.
Tune measurements with DTT data (txt (dt=2s),gif)
Saturday 26 March 2022 (20h00-0h00) (csr saveset 164247 (flat orbit) with shaker amplitude settings H/V 1462/197)
Elog entry (Phase files 29275 (flat orbit, H/V tunes 222/250 kHz), 29276-29302)
Phase files 29293-29302 were recorded during the calibration of sextupole 36E.
Used model 290. Used average of 16 DTT readings and recorded a phase file for each setting.
Ran the CesrV script calsex_loop.cesrv to record the calibration data.
Tune measurements with DTT data (txt (dt=2s),gif)
Saturday 19 March 2022 (7h00-12h00) (csr saveset 164038 (CHESS ops orbit) with shaker amplitude settings H/V 3350/653 for sextupoles 16 & 17, then 1462/197 for the rest)
Elog entry (Phase files 29262 (flat orbit) - 29263 (injection orbit, not flat)
Obtained calibration and offset data for sextupoles 15w (twice), 16w, 17w, 21w, 22w, 24w, 25w, 45w and, accidentally, 19w.
Also obtained calibration and offset data for the 38 sextupoles on the east side of the ring.
Used model 288. No additional averaging, no phase measurement or TBT data for each sextupole.
Note added 31 March: This calibration and offset data was inadvertently recorded with the CHESS injection orbit rather than with the flat orbit.
The analysis was done using model 291 (derived from phase file 29263) for this reason.
Ran the CesrV script calsex_loop_no_phase_tbt.cesrv to record the calibration data.
Tune measurements with DTT data (txt (dt=2s),gif)
Thursday 17 March 2022 (7h00-12h00) (csr saveset 163987 (flat orbit) with shaker amplitude settings H/V/L 3350/653/1380)
Elog entry (Phase files 29198-29239)
Implemented reading model file (288) with model optimized using phase 29198 with flat orbit for use by calibrate_sextupole and sextupole_analysis.
Implemented custom calibration parameters (dQ_max_sex_calib and sex_calib_delta_cu) for each sextupole.
Implemented 1-second averaging option (sex_calib_n_avg) in calibrate_sextupole.
Ran the CesrV script calsex_loop_no_phase_tbt.cesrv
in auto-mode continuously for the final 2 1/2 hrs of the shift, recording calibration data)
for sextupoles from 09AW,10W,10AW,12W, 39W. N_avg set to 4 for 39W and 20 for the others.
Tune measurements with DTT data (txt (dt=2s),gif)
Sunday, 16 January 2022 (12h00-20h00) (csr saveset 163307 (flat orbit) with shaker amplitude settings H/V/L 3350/653/1380)
Elog entry (Phase files 29062-29136, all prior to the debugged calibrations)
Found and fixed a number of bugs in the CesrV> calibrate sextupole command. Ran the CesrV script calsex_loop_no_phase_tbt.cesrv
in auto mode continuously for the final two hours of the shift with only two interruptions, recording calibration data)
for 39 sextupoles from 09AW to 47W, i.e. the entire west half of the ring.
All tune and phase measurements were recorded before the fully-debugged calibrations began at 18:00.
Tune measurements with TBT data (txt,gif)
Tune measurements with DTT data (txt (dt=2s),gif)
Friday, 14 January 2022 (13h00-16h00) (csr saveset 163281 (flat orbit) with shaker amplitude settings H/V/L 3350/653/1380)
Elog entry (Phase files 28961-29058)
K2 scans for 34w, 15w, 16w with 9 settings over +-24k cu with a flattened orbit, 3 phase files each.
Tune measurements with TBT data (txt,gif)
Tune measurements with DTT data (txt (dt=2s),gif)
Tuesday, 2 November 2021 (16h00-21h00) (csr saveset 162939 (flat orbit) with shaker amplitude settings H/V/L 3350/653/1380)
Elog entry (Phase files 28647-28936)
K2 scans for 34w, 18w-24w, 25w, 26w, 30w, 13w, and 14w with 9 settings over +-24k cu with a flattened orbit, 3 phase files each.
K2 scans for 33w, 33e, 34w with 9 settings over +-30k cu with a flattened orbit, 3 phase files each.
Tune measurements with TBT data (txt)
Tune measurements with DTT data (txt (dt=2s),gif)
Tuesday, 23 October 2021 (16h00-20h00) (csr saveset 162867 (flat orbit) with shaker amplitude settings H/V/L 1884/653/1380)
Elog entry
K2 scan for 10aw with 11 settings over +-30k cu with a flattened orbit, 3 phase files each. (Phase files 28607-28639)
Tune measurements with TBT data (txt)
Tune measurements with DTT data (txt (dt=2s),gif)
Tuesday, 22 June 2021 (19h00-22h00) (csr saveset 161790 with shaker amplitude settings H/V/L 603/170/1380)
Elog entry
K2 scans (11 K2 settings, +-30k cu, 3 phase measurements each) for 10ae, 9ae, 9aw, 10w, 12w (Phase files 28209-28462)
Tune measurements with TBT data (txt,gif)
Tune measurements with DTT data (txt (dt=3s),gif)
VBSM measurements (txt,gif)
The H shaking amplitude setting (603) gave a setting of -24.7 dB. Following the 10ae K2 scan, the amplitude was increased to -20 dB, reducing noise in the TBT data.
Sunday, 30 May 2021 (13h00-18h00) (csr saveset 161790 with shaker amplitude settings H/V/L 603/170/1380)
Elog entry
K2 scans (5 K2 settings, +-12k cu, 3 phase measurements each) for 34e-17e (Phase files 27701-28023)
K2 scans (9 K2 settings, +-12k cu, 3 phase measurements each) for 16e-11e (Phase files 28024-28196)
Tune measurements with TBT data (txt,gif)
Tune measurements with DTT data (txt (dt=3s),gif)
VBSM measurements (txt,gif)
Saturday, 29 May 2021 (12h00-18h00) (csr saveset 161774 with shaker amplitude settings H/V/L 603/170/1380)
Elog entry
K2 scans (7 K2 settings, +-18k cu, 3 phase measurements each) for 41e-35e (Phase files 27486-27697)
Tune measurements with TBT data (txt,gif)
Tune measurements with DTT data (txt (dt=3s),gif)
VBSM measurements (txt,gif)
Sunday, 11 April 2021 (12h00-18h00) (csr saveset 161254 with shaker amplitude settings H/V/L 3350/279/1380)
Elog entry
K2 scans (3-5 settings, 3 phase measurements each) for 30w-32w, 34w-42e (Phase files 27046-27419)
Sextupole 34w shows anomalously large tune shift similar to that measured for 10aw/e.
Tune measurements with TBT data (txt,gif)
Tune measurements with DTT data (txt (dt=3s),gif)
VBSM measurements (txt,gif)
Monday, 22 February 2021 (16h00-20h00) (csr saveset 160823 with shaker amplitude settings H/V/L 1500/170/1380)
Elog entry
CesrV sextupole calibrations for 10aw-17w, 10ae (Phase files 26664-26731)
K2 scans (3 settings) for 9ae, 10ae, 25w, 26w, 27w, 28w, 29w, 30w (Phase files 26732-26755)
Sextupole 10ae shows anomalously large tune shift similar to that measured for 10aw.
Tune measurements with TbT data (txt (dt=80-90s),gif)
Tune measurements with DTT data (txt (dt=10s),gif)
Sunday, 21 February 2021 (12h00-16h00) (csr saveset 160798 with shaker amplitude settings H/V/L 1500/170/1380)
Elog entry
K2 scans (3 settings) for 09aw (26532-26540), 10aw (26550-26558), 12w-24w (Phase files 26526-26627)
Some K2 scans taken with 3 phase measurements and 3 sets of turn-by-turn data, some with a single set each.
Fine K2 scan (3 phase measurements for each of 11 settings) for 10aw (26628-26660)
K2 scan with 131k turns for 15w (26586-26594). (All others with 32k turns)
17w data obtained for both a single set (26604-26606) and for 3 sets (26595-26603).
Tune measurements with TbT data (txt (dt=10-20s),gif)
Tune measurements with DTT data (txt1 (dt=3s),txt2 (dt=10s),gif1,gif2)
VK slides comparing DTT and TbT tune measurements (pdf)
Friday, 19 February 2021 (17h00-21h00) (csr saveset 160798 with shaker amplitude settings H/V/L 1500/170/1380)
Elog entry
K2 scans (3 settings) for 09aw, 10w, 10aw (26503-26505), 12w-15w, 09ae (Phase files 26468-26514)
Sextupole 10aw shows anomalously large tune shift corresponding to a sextupole-center/beam offset of about 5 mm.
Fine K2 scan (21 settings) for 12w (Phase files 26482-26502)
Tune measurements with TbT data (txt (dt=15s),gif)
Tune measurements with DTT data (txt (dt=7s),gif)

Post-processing Analysis

Calibration and horizontal offset analysis for the 16 January 2022 data.
Calibration correction factors are formatted for a custom calibration file.
Instructions for using custom calibration files in CesrV are here.
Sextupole offset data are formatted for Bmad lattice files and text which can be included in a CesrV script.
Measured orbits and phase functions, DTT tunes, sextupole settings, ring element tables for all phase files are available here. (266 text files)
Results for model optimizations fit to the orbit and phase measurements are also included.
JAC and DCS wave analysis results of 17 March 2021 (pdf)
GHH analysis wave results of 12 March 2021 (xls)
Physics Analysis Workstation manual (pdf)

Useful Tables

Tao table of sextupoles and BPMs with beam tracking (twiss, beam sizes) (txt)
Design sextupole settings (txt)

Photographs of Sextupole Magnets In Situ

Sextupole pictures (pptx)
Sextupole wiring changes for 35W, 36W, 40W and 42W, 14 April 2023. For each sextupole, three pictures: 1) Quadrupole and sextupole, 2) sextupole power leads before braiding, 3) sextupole power leads after braiding. (url)
Sextupole wiring 33W and 34W 4 April 2023. No changes made. (url)
Sextupole wiring 28 February 2023. Pics 2 and 5 show 34E wiring before and after braiding the leads. (url)
Sextupoles and CBPM processors 21 February 2023. (url)

Presentations

J.A. Crittenden (10 April 2024) BPM/Quadrupole Offset Measurements of 26 March 2024 and BPM Recalibration Study with Updated Offset Values
J.A. Crittenden (28 March 2024) BPM/Quadrupole Offset Measurements of 26 March 2024
J.A. Crittenden (20 March 2024) BPM/quadrupole offset Measurement Studies (pdf, text)
J.A. Crittenden (21 February 2024) First Look at BPM Residuals Analysis: 2021-2023 Phase File Optimizations Using Sextupole Studies
J.A. Crittenden (10 January 2024) Results of the October Sextupole Studies
J.A. Crittenden (8 November 2023) Effect of BPM gain calibration and quadrupole offset correction on sextupole misalignment measurement: 26W
J.A. Crittenden (19 October 2023) Summary of October 2023 Sextupole Studies
J.A. Crittenden and W.J. Carbonell (25 July 2023) Proposed Resolution of the Beam Size Measurement Puzzle
J.A. Crittenden (19 July 2023) Summary of the 2023 Sextupole K2 Scan and Calibration Data
J.A. Crittenden and W.J. Carbonell (6 July 2023) Correction to the Beam Size Calculation Due to the Finite Length of the Sextupole
J.A. Crittenden (21 April 2023) CESR Sextupoles: Results of the Stray Field Tests
J.A. Crittenden (11 April 2023) First Results from the Tao Model for Measuring Beam Size with Sextupole Magnets
J.A. Crittenden (29 March 2023) Sources of Systematic Error in the Measurement of Beam Size Using Sextupole magnets 1. Stray Fields
J.A. Crittenden (15 February 2023) Effects of Horizontal and Vertical Sextupole Misalignments
J.A. Crittenden (6 January 2023) Recent Analysis of the Sextupole Strength Scans for the Complete Data Set
J.A. Crittenden (14 December 2022) Sextupole Alignment and Beam Size Measurement
J.A. Crittenden (22 November 2022) Comparison of Sextupole Offset Calculations in the CesrV Sextupole Calibration Analysis
J.A. Crittenden (10 October 2022) "Statistical Error" in Beam Size Calculation in Tao is not Statistical
J.A. Crittenden & Ariel Shaked (26 September 2022) Beam Size Measurement for Sextupoles of Opposite Polarity
J.A. Crittenden (1 June 2022) Results for CESR Sextupole Calibration Correction Factors and Horizontal Offsets-IPAC22 Poster
J.A. Crittenden (28 April 2022) CESR Sextupole Calibration and Horizontal Offset Results from 26 April 2022
J.A. Crittenden (10 March 2022) CESR Sextupole Calibration and Horizontal Offset Results from 16 January 2022
J.A. Crittenden (9 February 2022) Modeling Tune Shifts from Sextupole Offsets using CesrV
J.A. Crittenden (2 February 2022) Tune Shifts from Skew Quad Contributions (II) (Hoffstaetter Mathematica notebook)
J.A. Crittenden (5 January 2022) Tune Shifts from Normal and Skew Quad terms in Sextupoles
J.A. Crittenden (8 December 2021) Two-dimensional Beam Size Analysis with Sextupoles
J.A. Crittenden (3 November 2021) Initial Results from the October Machine Studies on Sextupoles
J.A. Crittenden (14 October 2021) Resolution of the Quadratic Dependence of Tune on Sextupole Strength
J.A. Crittenden (9 September 2021) CESR Tune Measurement Precision
J.A. Crittenden (26 August 2021) CESR Sextupole Calibration
J.A. Crittenden (15 June 2021) Single-kick Analysis of Difference Orbits
J.A. Crittenden (10 June 2021) Uncertainty Propagation for Beam Size Determination Using Sextupoles
J.A. Crittenden (12 May 2021) Modeling the Contribution to Tune from All Sextupoles Using CesrV)
J.A. Crittenden (29 April 2021) Measuring Beam Size with dK1L(dK2L)
J.A. Crittenden (28 April 2021) Update on Analysis of Measurements of Beam Size in Sextupoles
J.A. Crittenden (25 March 2021) Initial Results from Machine Studies 19-22 Feb 2021, Comparison of TBT and DTT tune measurements
J.A. Crittenden (17 February 2021) Machine studies plan for beam size measurement using sextupoles
J.A. Crittenden (10 February 2021) Tao Modeling for Zero-size Beam in a Sextupole
J.A. Crittenden (3 February 2021) Measuring Beam Size with Sextupoles - Test with beam tracking in Tao

Applied and Engineering Physics Masters of Engineering Project

A. Shaked, Modeling Horizontal Beam Size Calculations Using_Sextupoles, 19 May 2023, (Final report)

National Science Foundation Research for Undergraduates Projects

W. Carbonell, Investigation of Systematic Contributions to and Error in the Beam Size Measurement using Sextupole Magnets in Storage Rings, 2023, Final report
I. Mishra, Updates on Beam Size Measurement using Sextupole Magnets in Storage Rings, 2022, (Introduction, Final report)
A. Fagan, Beam Size Measurement using Sextupole Magnets in CESR, 2021, (Introduction, Final report)

Relevant Publications and Technical Notes

J.A. Crittenden et al., abstract submitted to 15th International Accelerator Conference, 19-24 May 2024, Nashville, Tennessee, Recent Developments in the Study of Beam Size Using Sextupole Magnets (abstract)
J.A. Crittenden et al., Proceedings of the 14th International Accelerator Conference, 7-12 May 2023, Venice, Italy, Study of the Systematic Error Contributions to the Measurement of Beam Size Using Sextupole Magnets (paper, poster)
J.A. Crittenden et al., Proceedings of the 13th International Accelerator Conference, 12-17 June 2022, Bangkok, Thailand, Progress on the Measurement of Beam Size Using Sextupole Magnets (paper, poster)
C.E. Gonzalez-Ortiz et al., Proceedings of the 13th International Accelerator Conference, 12-17 June 2022, Bangkok, Thailand, Third-order Resonance Compensation at the FNAL Recycler Ring (paper)
D. Sagan, Calculating Sextupole Strength and Placement from Shaking Data, 2017 (unpublished)
A. Xiao and V.Sajaev, Proceedings of 2013 Particle Accelerator Conference, Pasadena, CA, USA (2013), Abstract TUPAC08, Beam-based Alignment of Sextupoles at the APS
R.E. Meller and M.A. Palmer, Proceedings of 2011 Particle Accelerator Conference, New York, NY, USA (2011), Abstract MOP215, Digital Tune Tracker for CESR
D. Sagan, R. Meller, R. Littauer and D. Rubin (Phys. Rev. STAB Vol 3, 092801 (2000)) Betatron phase and coupling correction at the Cornell Electron/Positron Storage Ring
D. Sagan and D. Rubin(Phys. Rev. STAB Vol 2, 074001 (1999)) Linear Analysis of Coupled Lattices
J. Bengtsson, The Sextupole Scheme for the Swiss Lights Source (SLF): An Analytic Approach, 1997
A. Mikhailichenko, CBN 98-2, Sextupole for CESR (1998)
A. Mikhailichenko, CON 96-5, CESR Sextupole Upgrade (1996)
D. Larson, L. Roberts and Richard Talman, CBN 78-1, Sextupole Magnetic Measurements (1976)

Prior Machine Studies

J.A. Crittenden and D. Sagan, History of Sextupole Calibration Runs October/2002 and September/2003 (html)

crittenden@cornell.edu
Jim Crittenden
Wilson Synchrotron Laboratory
Room 212
Phone:(607) 255-4882