CLIC Beam Delivery System R. Tomás Thanks to H. Braun, A. Latina, J. Resta and D. Schulte April 2007 Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.1/18
� � � � � � � Contents Status of the CLIC BDS: The new diagnostics section FFS optimization and shortening overview Impact of new parameters on: FFS optimization Collimation Luminosity with beam jitter Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.2/18
� � ✄ ✁ ✄ � ✟ � ✠ ✡ ✞ ✆ ✞ � � � � � � Goals & Requisites of Diagnostics Goals: Coupling correction Emittance measurement Energy measurement (placed in collimation section to save space) Requisites: 4 skew quadrupoles 4 laser wires either or: located at ☎✝✆ (present technology) �✂✁ able to measure Photon detector Precise dipoles and BPMs Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.3/18
� ✞ ✆ ✞ ✄ ✁ � Diagnostics optics & layout SQ1 SQ2 SQ3SQ4 LW1 LW2LW3 LW4 Diagnostics section 600. β x (m), β y (m) β y β x 500. 400. 300. 200. 100. 0.0 0.0 200. 400. 600. 800. 1000. Momentum offset = 0.00 % s (m) This is for existing laser wire technology ☎✝✆ If new BSM measures > 0.4 , length 400m. Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.4/18
Full BDS 600 β x Energy β y collimation 500 FFS Diagnostics Betatron collimation 400 1/2 [m 1/2 ] 300 β x,y 200 100 0 0 500 1000 1500 2000 2500 3000 3500 Longitudinal location [m] Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.5/18
Layout & photon collection Beam diagnostics beam line 0.1 Horizontal displacement [m] 0.05 photon detector Laser wire photons 0 -0.05 Dipoles for energy col. -0.1 400 500 600 700 800 900 1000 1100 1200 Longitudinal location [m] Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.6/18
✟ ✆ ✄ � � ✂ ✄ ✄ ☎ ✞ ✝ ✂ ✞ � ☎ ☛ ✞ ✠ ☞ ✄ PLACET simulations, Andrea Latina Realistic simulations: beam size at laser wire 1 -Quadrupole rolls ( ) � ✁� 1.8 before correction -Radiation after correction 1.7 Correction works up to 1.6 1.5 σ y [ µ m] 1.4 1.3 1.2 1.1 1 1 10 100 1000 10000 σ roll [ µ rad] Strength of the skew quadrupoles as a function of σ roll 1e-04 SKEW1 SKEW2 8e-05 SKEW3 Maximum strength ✟ ✡✠ SKEW4 6e-05 4e-05 K1 S L [m -1 ] 2e-05 0 -2e-05 -4e-05 Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.7/18 -6e-05 1 10 100 1000
� � � � � � � � FFS shortening and optimization I Advantages of a shorter FFS: Shorter tunnel Lower beta peak (better stability) Lower chromaticity (smaller aberrations) Shorter L Disadvantages: Shorter L (detector and solenoid constrains) Stronger focusing (quad field) Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.8/18
� � FFS shortening and optimization II FFS shortening and optimization chart 8 Removing one dipole, adding one octupole, adding one decapole Total luminosity [a.u.] 7 Adding one sextupole Full non-linear and disp optim. (2007) (2006) 6 5 Sextupole optimization Nominal FFS 4 340 360 380 400 420 440 460 480 500 520 540 560 FFS Length [m] L =2.6m L =4m Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.9/18
� � New parameters and FFS optimization 16 N=5.8 10 9 , σ z =75 µ m factor 1.8 ± 0.2 N=5.2 10 9 , σ z =62 µ m 14 Luminosity per interaction [a.u.] N=4.0 10 9 , σ z =35 µ m 12 10 factor 1.6 ± 0.2 8 6 4 2 0 3 3.2 3.4 3.6 3.8 4 σ x [10 -8 m] Close to linear Lumi Vs. charge and Lumi Vs. Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.10/18
☎ ✆ ✟ ✠ ✞ ✆ ✝ ✠ ✝ ✟ ☎ ☎ ☎ ✡ ✄ ✂ ✁ � ✠ ✟ New parameters and Collimation I Survival plot from CLIC note 477 and J. Resta’s thesis for different materials: 154 bunches/train 0.666 ns 311 bunches/train 0.667 ns New parameters rule out Be collimators! Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.11/18
� � � � � � New parameters and Collimation II Possible solutions: Carbon collimator largest impedance larger betas longer system ( 1 km more) non-linear collimation system slightly lower luminosity lower charge lower luminosity consumable collimators technologically complex Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.12/18
New parameters and Collimation II Example of a rotary consumable collimator designed for NLC: Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.13/18
Vertical jitter, Andrea Latina & Daniel Vertical Beam Jitter at the entrance of the BDS 1.1 NO COLL, CHARGE= 5.8e9 * 0.9 0.7 COLL, CHARGE = 5.8e9 * 0.9 1.05 0.7 1 0.95 L/L 0 0.9 0.85 0.8 0.75 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 Y offset / σ y Higher charge enhances the luminosity loss with beam jitter due to beam-beam disruption and collimator Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.14/18 wakefields.
� � � � � � � Summary FFS optimization is charge independent (so far) BDS length with Diagnostics section and short FFS: Existing laser wire technology 3.2 km Assuming better BSM 2.7 km Be collimators do not survive Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.15/18
ILC beam diagnostics section 350 β x β y 300 250 200 β x,y [m] 150 100 50 0 0 100 200 300 400 500 600 700 Longitudinal location [m] Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.16/18
FFS optimization 8e+34 CLIC machines 1/x 7e+34 example path 6e+34 Luminosity [a.u.] 5e+34 4e+34 3e+34 2e+34 1e+34 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 * σ y * [10 -15 m 2 ] σ x Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.17/18
✁ ✆ ✞ ☎ ✝ ✆ ✝ ✆ ☎ ✝ ☎ ✄ ✟ ✟ ✂ � ✁ � ✁ ✆ ✂ ✁ � � ✆ ✁ � � ✆ Optics table Element Location SQD1 130 27 138 0 0 SQD2 217 27 138 90 90 SQD3 341 27 138 270 180 SQD4 428 27 138 360 270 LW1 462 49 312 0 0 LW2 594 141 302 39 45 LW3 647 139 302 64 54 LW4 855 101 393 123 120 = 1 m Rogelio Tom´ as Garc´ ıa CLIC Beam Delivery System – p.18/18
Recommend
More recommend
