Report from trip to ATF R. Tomás CLIC seminar - 2008 Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.1/20
Contents • IP configuration • Shintake monitor • Honda monitor • FONT: Fast Feedback system • ATF2 FFS tuning simulations • Flight simulator • Damping Ring BPMs • Measurement of resonance terms in the DR Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.2/20
✝ ☎ � ☎ ☎ ✟ ✆ � ✆ ☎ ✂ � � ☎ � ✂ ✂✞ ☎ ✄ ☎ ☎ ✁ ✂ ☎ ✝ ☎ ☎ ✂ ☎ ✂ ☎ ☎ ✂ ✄ ✆ ✂ ☎ ✂ � ✂ � ✁ ✂ ✄ ☎ ☎ � ✄ ☎ � ☎ ☎ ☎ ✂ � ☎ ☎ � ✆ ✝ IP configuration p r e s e n t e d a t d Sweeping Honda Magnet Monitor Carbon Wire Scanner Shintake Monitor Area C-band Screen S-band BPM Monitor S m a l l BPM 2 0 0 QD0 ✟✡✠ I P - B P M I P Very cluttered IP area!! Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.3/20
Shintake monitor New Shintake monitor with extra laser channels with larger angle to extend the measurable size range up to the 5 µ m. Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.4/20
Honda beam size monitor New conceptual beam size monitor to be tested and used in ATF2, the range is 0.3-2 µ m Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.5/20
FONT: Fast Feedback system F B o f f F B o f f n t s ) D C c o u 1 5 4 n s t i o n ( A D F B o n F B o n a m P o s i B e a c o r r e c t e d ! c o r r e c t e d ! ‘ b a n a n a ’ e f f e c t b a n a n a e f f e c t A T F 2 m e e t i n g , K E K , 1 9 / 1 2 / 0 7 P . N . B u r r o w s 1 3 Oxford + Daresbury managed to prove 140ns latency feedback! Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.6/20
ATF2 FFS tuning simulations I G. White predicts one week of tuning for achieving ≈ 35nm vertical spot size. Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.7/20
ATF2 FFS tuning simulations II 12 10 8 Counts 6 4 2 0 500 1000 1500 2000 2500 3000 3500 Number of iterations A. Latina and myself predicted 3 days of tuning with more optimistic assumptions. Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.8/20
Flight Simulator • The machine should be operated by computers • Algorithms should be tested with simulations • Code philosophy: any code should be usable (SAD, MAD, Lucretia, PLACET, etc) • G. White has built a server that would communicate with the machine from any code. • We are very interested on using PLACET! Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.9/20
✄ �☎ ✁ ✂ �✁ Damping Ring BPMs 1 5 3 8 3 6 3 6 1 3 1 3 1 1 4 0 9 4 2 4 2 7 7 4 4 5 4 6 3 4 8 1 5 0 9 5 5 2 5 2 9 3 9 3 5 4 5 6 8 B P M s F e b 0 7 1 2 x B P M s M a y 0 7 C A L s i g n a l M a y 0 7 C A L p r o t o t y p e t e s t D e c 0 7 ( e x t r a V M E c r a t e ) FNAL people are installing turn-by-turn electronic boards for the BPMs. Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.10/20
Measurement of resonance terms 2006 experience ATF report 06-08 Oscillation amplitude: 2.25mm at start of ATFDR 0.05 0.04 Line(-2,0)/Line(1,0) 0.03 0.02 0.01 Experiment (06apr11-033144) Simulation (with decoherence) 0 60 70 80 90 100 110 120 Longitudinal location[m] Horizontal resonance (3,0) successfully probed via spectral line -2 Q x . However vertical plane totally unprobed. Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.11/20
Spectrum from November’s data Vertical spectrum BPM47 (amplitude= 82 units) 30 2Qs? 25 Qy 20 Amplitude 15 10 Qx 2Qy? 5 0 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 Frequency [tune units] Q x line comes from linear coupling. 2 Q y line related to resonance (0,3). This resonance is driven by skew sextupoles. Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.12/20
✙ ✞ ✦ ✁ ✛ ✝ ☎ ✢ ✜ ✁ ✘ ✧ ✖✗ ✕ ☛ ✏ ☎ ✑ ✎ ✄ ✍ ✛ ✘ ✁ ✁ ☎ ☎ ✁ ☎ � ✁ ☎ ✞ ✄ ☎ ✬ ✪✫ ✛ ✥ ✩ ✖ ✕ ✖ ✩ ✄✏ ✍ ✆ ✄✝ ☎ ☛ � ☎ ✁ ✄✞ ✁ � ☎ ✟ ✆ ✄ ✁ � ✄☎ ✁ � � ✄ ☎ ✠ ✌ ✡ ☞ ✡✝ ✁ � ✡ ✡ ✁ � ✆ ✁ � � ✡☛ ✁ � ✡☎ � ✄ ✡ ✁ ✁ p.13/20 – ATF Average coupling = 2.5% ± 0.3%, (quite flat). to Coupling: December’s tune scan trip from Report ☎✂✎ �✂✁ �✂✁ ✗✔★ ✗✔✥ ✖✗✔✥ ✣✔✤ �✂✁ ✚✔✛ ✒✔✓ �✂✁ �✂✁ ıa Garc´ as Tom´ Rogelio
Skew sextupolar resonances • Skew sextupoles produce non-linear coupling that deteriorates ǫ y , trough the term yx 2 . • The nearest skew resonance to the ATF tunes is (2,1) • and its spectral line is 2 Q x in the vertical plane. • Can we measure it? Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.14/20
Skew resonance (2,1): December’s tune scan ✖ ✁ � � � ✁ � ✭ ✫✬ ✛ ✦ ✪ ✕ ☛ ✖ ✪ ✘ ★ ✛ ✧ ✦ ✗ ✛ ✢✣ ✜ ✙ ☎ � ✖✗ ☛ � � ✁ ☎ ☛ ✮ ✁ ✄ � ☛ ✁ ✄ ☎ ✁ ✁ ✄ � � ✁ ✄ ☛ ✮ ✁ � � ☛ ✘ ✖ ✕ ☎ ✁ � ☛☎ ✁ � ✔ ☛ ✁ � ☎ ☎ � ✄✞ � ✁ � ✄✝ ✁ � ✆ ✄ ✁ � ✄☎ � ✄ ☛☞ ✄ ✁ ✍ ✓ ✑ ☎ ✒ ☛ ✄ ✎ ✄✑ ✎ ✏ ✌ ✁ ✆ ✁ ☛ ☛ � � ☛ ✝ p.15/20 – ATF to trip from Report ☎✂✏ �✂✁ �✂✁ ✗✡✩ ✟✡✠ ✗✡✦ ✤✡✥ ✚✡✛ �✂✁ �✂✁ ıa Garc´ as Tom´ Rogelio
New BPMs Spectrum of Vertical New BPM #44 70 Qx 60 50 Amplitude [ µ m] 40 30 20 Qy Garbage 10 Qx+Qy 2Qx 0 0 0.1 0.2 0.3 0.4 0.5 Frequency [tune units] New DR BPMs are still under commissioning. They have low frequency noise and synchronization problems, but let’s look! Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.16/20
✚ ✚ ✔ ✕ ✪ ✩ ✖ ✗ ★ ✧ ✪ � ✦ ✗ ✥ ✖ ✤ ✣ ✕ ✥ ✜ ✴ ✽ ✿ ✸ ✶ ✰ ✹ ✸ ✴ ✚ ✳ ✱✲ ✰ ✯ ✮ ✭ ✬ ✫ ✢ ✛ ✶ ✆ ✡ ✠ ✟ ✞ ✝ � � � ☞ ☎ � ✄ � ✂ � ✁ ☛ ✌ ✚ ✒ ✙ ✘ ✗ ✖ ✕ ✔ ✓ ✑ � ☎ ✏ ✄ ✎ ✂ ✍ ✁ ✆ ✾ New BPMs, 2Qx line around the ring ✵✷✶ ✺✻✷✼ ✻✷✼ This might indicate source of skew sextupolar fields or faulty BPM... Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.17/20
Correction • Linear coupling can be corrected with existing skew quads. • Non-linear coupling correction can be achieved in two ways: • Localization of source and direct fix • or needs installation of skew sextpoles. Before action, estimates on ǫ y improvement should be computed. Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.18/20
Coupling correction simulation W- (identical to f 1001 ) 0.2 Real (uncorrected) 0.15 Real (corrected) Imaginary (uncorrected) 0.1 Imaginary (corrected) 0.05 0 W- -0.05 -0.1 -0.15 -0.2 0 20 40 60 80 100 BPM # E. Gianfelice and Y. Alexain propose simultaneous correction of coupling and vertical dispersion at the BPMs to get lowest ǫ y in the ATF DR. Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.19/20
Summary • A good fraction of LC technology is being tested in ATF/2 • We should use this facility to test CLIC concepts • Measurement of resonance terms might improve electron rings performance Rogelio Tom´ as Garc´ ıa Report from trip to ATF – p.20/20
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