Transverse beam profile measurement with the BGV demonstrator

Transverse beam profile measurement with the BGV demonstrator Sotiris Vlachos on behalf of the BGV Collaboration 24/05/2018 Sotiris Vlachos 1

The BGV Detector 24/05/2018 Sotiris Vlachos 2

2018 BGV status • L 0 Trigger system has been upgraded • Constant fraction discriminator • Logic unit with adaptable delays • Detector is operational, • Measurements take place by BGV experts at all energies, intensities (only effects integration time) • Data processing off-line, analysis latency ~ 6 hours (no automatic DB logging) • Aim for on-line data measurements (rate dependent on CPU power) 24/05/2018 Sotiris Vlachos 3

Beam width measurement • Track 1 Track 2 y IP 1 x IP 2 24/05/2018 Sotiris Vlachos 4

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Slices in Time 5 sec 24/05/2018 20 sec 60 sec Sotiris Vlachos 6

Raw Beam width [mm] 24/05/2018 [mm] Sotiris Vlachos 7

Beam width - Monte-Carlo correction • Correction using simulated data Generated beam width [mm] 0. 9 0. 8 0. 7 0. 6 0. 5 0. 4 0. 3 0. 2 0. 1 0 0. 000 0. 100 0. 200 0. 300 0. 400 0. 500 0. 600 0. 700 0. 800 Measured beam width [mm] 24/05/2018 Sotiris Vlachos 8

Beam width - Monte-Carlo corrected 24/05/2018 Sotiris Vlachos 9

Real data corrected Beam width [mm] 2. 5 Te. V stable beams 24/05/2018 Sotiris Vlachos 10

Resolution vs integration time The longer the integration time the higher the precision (until ~3µm) Error [mm] Error vs number of entries (log 2 plot) 24/05/2018 Sotiris Vlachos 11

Corrected BGV beam width 24/05/2018 Sotiris Vlachos 12

Corrected BGV beam width Time to energy conversion using logging. DB 24/05/2018 Sotiris Vlachos 13

Typical BGV measurements Fill # 6371 (6. 5 Te. V) 6358 (450 Ge. V) 6386 (2. 5 Te. V) 6399 (2. 5 Te. V) 24/05/2018 Integration time (sec) Beam width x (μm) Beam width y (μm) Error x (μm) Error y (μm) Rel. Error 3 180 215 28 34 16 % 20 182 217 10 13 6 % 60 182 217 6 7 3 % 3 731 761 31 43 5 % 20 732 762 14 18 2 % 60 734 764 6 14 1 -2 % 20 302 325 9 11 3 % 60 302 325 5 6 2 % 20 331 355 8 10 3 % Sotiris Vlachos 14

BGV vs BSRT Corrected values and BSRT values for σx Beam width [mm] 0. 800 BSRT 0. 45 0. 731 0. 622 2. 5 0. 332 0. 302 6. 5 0. 181 0. 184 450 Ge. V 0. 700 0. 600 0. 500 2. 5 Te. V 0. 400 6. 5 Te. V 0. 300 0. 200 0. 100 0. 000 2697 2707 2717 2727 BGV Run Number Corrected x 24/05/2018 BGV BSRT x 2737 2747 2757 20 s integration time Sotiris Vlachos 15

BGV vs BSRT Corrected values and BSRT values for σy Beam width [mm] 0. 800 BSRT 0. 45 0. 762 0. 665 2. 5 0. 348 0. 323 6. 5 0. 216 450 Ge. V 0. 700 0. 600 0. 500 2. 5 Te. V 0. 400 6. 5 Te. V 0. 300 0. 200 0. 100 0. 000 2697 2707 2717 2727 BGV Run Number Corrected y 24/05/2018 BGV 2737 2747 20 s integration time 2757 BSRT y Sotiris Vlachos 16

Beam width evolution during ramp Fill #6358 ramp 40 s integration time 0. 800 Beam width [mm] 0. 700 0. 600 0. 500 0. 400 0. 300 0. 200 0. 100 0. 0 1000. 0 2000. 0 3000. 0 4000. 0 5000. 0 6000. 0 7000. 0 Beam energy [Ge. V] corrected_sigmax 24/05/2018 corrected_sigmay estimated x estimated y Sotiris Vlachos 17

measurement/prediction Measured value vs Estimated value - x 1. 200 1. 100 1. 000 0. 900 0. 800 0. 0 1000. 0 2000. 0 3000. 0 4000. 0 5000. 0 6000. 0 7000. 0 Beam energy [Ge. V] Measured value vs Estimated value - y 1. 200 1. 100 1. 000 0. 900 0. 800 0. 0 1000. 0 2000. 0 3000. 0 4000. 0 5000. 0 Beam energy [Ge. V] 24/05/2018 Sotiris Vlachos 18

Beam width vs BCID 24/05/2018 Sotiris Vlachos 19

17/5/2018 6. 5 Te. V stable beams 10 sec integration time σx = 205 ± 7 μm σy = 205 ± 9 μm 24/05/2018 Sotiris Vlachos 20

Expected 2018 performance Average beam width, 1 min integration time: Per Bunch Precision 5 min integration time: • 2 % precision @ 450 Ge. V • 3 % precision @ 6. 5 Te. V • For up to ~200 BCIDs • 8% precision @ 6. 5 Te. V HL-LHC BGV proposal beam width resolution: 2% in 1 min for 1011 p/bunch (average) 24/05/2018 Sotiris Vlachos 21

Backup 24/05/2018 Sotiris Vlachos 22

Vertex reconstruction 24/05/2018 Sotiris Vlachos 23

Vertex reconstruction 24/05/2018 Sotiris Vlachos 24

Resolution vs integration time Error [mm] The longer the integration time the higher the precision until ~3µm 24/05/2018 Sotiris Vlachos 25

All Tracks from the MC primary vertex • No selection applied (except the PV flag) • Should give a round beam and a flat t. Phi distribution • Effectively gives 0. 199 ± 0. 003 mm beam size 24/05/2018 Sotiris Vlachos 26

Reconstructable tracks (4+ clusters each in NEAR and FAR) • Geometry selection applied, theoretical limit of detector (coverage) • Shows the effect of the geometry on the reconstructed values, if the beam is not round here anymore the geometry influences the result even in MC. • Results: • Fit x: 0. 224 ± 0. 003 • Fit y: 0. 173 ± 0. 002 • Fit comb: 0. 201 ± 0. 002 • Shows that there’s a geometric effect since the beam is not perceived round anymore (but the average actually is) • The fit quality is actually very nice so it’s not a fit artifact • The tracks are taken from the truth values so there are no fitting errors either 24/05/2018 Sotiris Vlachos 27

All Reconstructed tracks (measurement) • Geometry and reconstruction limitations applied • Gives a value below the expected and different values for x and y beam width • Results: • Fit x: 0. 199 ± 0. 013 • Fit y: 0. 147 ± 0. 006 • Fit comb: 0. 174 ± 0. 007 • Uses reconstructed track information • The fit quality resembles the common one for reconstructed data • The results for x and y differ more dramatically now and the combination fit is not the correct value anymore 24/05/2018 Sotiris Vlachos 28