ATS or nonATS for 2017 S Fartoukh BEABP
ATS or non-ATS for 2017? S. Fartoukh BE/ABP 30/11/2016
Status • Optics ready and correctable for pp physics down to unbeatable b* State-of-the-art optics correction demonstrated at 40 cm and 21 cm IT aperture measured to ~9. 7 s with (non-optimally corrected) 33 cm optics with +/- 140 mrad crossing angle (9. 0 s for ge=2. 2 mm at 6. 5 Te. V) • To be done (by order of “easy-ness”) Vd. M optics and transition from injection in all 4 Ips IR 2 squeeze for ion collision optics (snapshot at 50 cm exist) Un-squeeze to 90 m ( snapshot at 90 m exist with right RP constraint) Pre-squeeze toward a re-optimized 40 cm optics for AFP/TOTEM (the 40 cm snapshot exists, is found to be comparable to the 2016 optics for AFP/CT-PPS) • Further optimization steps Combine ramp & squeeze down to b* =1. 2 m (instead of 3 m) Combine pre-squeeze and telescopic squeeze down to ~30 cm 30/11/2016 S. Fartoukh, ABP internal Evian Prep. meeting 30/11/2016 2
Some illustrations (1/3) • Measurement and correction at 40 cm (the AC-dipole was not working for B 1 H to re-measure after correction) 30/11/2016 Beam 1 S. Fartoukh, ABP internal Evian Prep. meeting 30/11/2016 Beam 2 3
Some illustrations (2/3) • Measurement at 33 cm 15 -20% b-beat (left uncorrected) 30/11/2016 Beam 1 S. Fartoukh, ABP internal Evian Prep. meeting 30/11/2016 Beam 2 4
Some illustrations (3/3) • Measurement and correction at 21 cm 30/11/2016 Beam 1 S. Fartoukh, ABP internal Evian Prep. meeting 30/11/2016 Beam 2 5
Squeeze time: first estimate (1/2) Present Combined Ramp & Squeeze (19 optics) Present pre-squeeze (3 m 40 cm) in 470 s 148 s from 3 m to 1. 2 m can be easily combined in the ramp 30/11/2016 S. Fartoukh, ABP internal Evian Prep. meeting 30/11/2016 6
Squeeze time: first estimate (2/2) Present pre-squeeze (3 m 40 cm) in 470 s Present tele-squeeze (40 cm 10 cm) in 804 s The telescopic squeeze from an arbitrary b* to 27/40 × b* takes 258 s but can be swallowed in the pre-squeeze itself from 1. 2 m to 40 cm (322 s) All together the squeeze duration from 1. 2 m to (even!) 27 cm could be shorten to 320 s, about 200 s longer forward physics re-optimised optics with a Q 6 reduced 12. 5 T/m (300 A) instead of 25 T/m (600 A), see later 30/11/2016 S. Fartoukh, ABP internal Evian Prep. meeting 30/11/2016 7
Compatibility with AFP (and CT-PPS) First results from M. Trzebinski (AFP) The present ATS (Q 6 @ 25 T/m) is not favorable: 15% lost in min. mass The new version (Q 6 @ 12. 5 T/m) is identical in this aspect to the 2016 nominal optics Further improvement are (always) possible but the price to pay will be the squeeze time (Q 6 gradient) 30/11/2016 S. Fartoukh, ABP internal Evian Prep. meeting 30/11/2016 8
Additional feature in mind (not ATS specific) Getting rid of the beam sensitivity to “approximate” coupling correction or drift over the year (. 31/. 32) is too close to the diagonal which is not justified w/o head-on Optics to be matched to the collision tunes (. 31/. 32) But all operation modes till ADJUST to be run with the injection tunes (0. 28/. 31), or equivalent e. g. (0. 29/. 31), using the RQTs (in s 23/34/67/78 for the ATS) Thank to Dario for the simulations 30/11/2016 S. Fartoukh, ABP internal Evian Prep. meeting 30/11/2016 9
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