Measurements, ideas, curiosities the straight path to high-energy physics… Complement to the presentation on Linear Colliders: ILC and CLIC F. Ruggiero Univ. “La Sapienza”, Rome, 20–24 March 2006
Linear Collider parameters (from the ILC-TRC/Second Report 2003) F. Ruggiero Linear Colliders: ILC and CLIC
SC vs NC projects in 1994: s =500 GeV The technology choice SC vs NC projects in 1994: s =500 GeV TESLA SBLC JLC-S JLC-C JLC-X NLC VLEPP CLIC f [GHz] 1.3 3.0 2.8 5.7 11.4 14.0 30.0 L1033 [cm-2s-1] 6 4 9 5 7 1-5 Pbeam [MW] 16.5 7.3 4.3 3.2 4.2 2.4 ~1-4 PAC [MW] 164 139 118 209 114 103 57 100 gey [10-8m] 50 4.8 7.5 15 sy* [nm] 64 28 3 7.4 F. Ruggiero Linear Colliders – ILC and CLIC
SC vs NC projects in 2003: s =500 GeV The technology choice SC vs NC projects in 2003: s =500 GeV TESLA SBLC JLC-S JLC-C JLC-X/NLC VLEPP CLIC f [GHz] 1.3 5.7 11.4 30.0 L1033 [cm-2s-1] 34 14 20 21 Pbeam [MW] 11.3 5.8 6.9 4.9 PAC [MW] 140 233 195 175 gey [10-8m] 3 4 1 sy* [nm] 5 1.2 F. Ruggiero Linear Colliders – ILC and CLIC
High acceleration gradient (150 MV/m) BASIC FEATURES OF CLIC High acceleration gradient (150 MV/m) OVERALL LAYOUT OF CLIC FOR A CENTER-OF-MASS ENERGY OF 3 TeV “Compact” collider - overall length 40 km Normal conducting accelerating structures High acceleration frequency (30 GHz) Two-Beam Acceleration Scheme Capable to reach high frequency Cost-effective & efficient (~ 10% overall) Simple tunnel, no active elements Central injector complex “Modular” design, can be built in stages
CLIC MAIN PARAMETERS at 3 TeV Center of mass energy Ecm 3000 GeV Main Linac RF Frequency fRF 30 GHz Luminosity L 6.5 1034 cm-2 s-1 Luminosity (in 1% of energy) L99% 3.3 Linac repetition rate frep 150 Hz No. of particles / bunch Nb 2.56 109 No. of bunches / pulse kb 220 Bunch separation Δtb 0.267 (8 periods) ns Bunch train length τtrain 58.4 Beam power / beam Pb 20.4 MW Unloaded / loaded gradient Gunl/l 172 / 150 MV/m Overall two linac length llinac 28 km Total beam delivery length lBD 2 x 2.6 Proposed site length ltot 33.2 Total site AC power Ptot 418 Wall plug (RF) to main beam power efficiency ηtot 12.5 %
THE CLIC TECHNOLOGY-RELATED KEY ISSUES AS POINTED OUT BY ILC-TRC 2003 Covered by CTF3 R1: Feasibility R1.2: Validation of drive beam generation scheme with fully loaded linac operation R1.1: Test of damped accelerating structure at design gradient and pulse length R1.3: Design and test of damped ON/OFF power extraction structure R2: Design finalization R2.1: Developments of structures with hard-breaking materials (W, Mo…) R2.2: Validation of stability and losses of DB decelerator; Design of machine protection system R2.3: Test of relevant linac sub-unit with beam R2.4: Validation of drive beam 40 MW, 937 MHz Multi-Beam Klystron with long RF pulse R2.5: Effects of coherent synchrotron radiation in bunch compressors R2.6: Design of an extraction line for 3 TeV c.m. * Feasibility study done – need development by industry. N.B.: Drive beam acc. structure parameters can be adapted to other klystron power levels * Covered by EUROTeV
THE CLIC RF POWER SOURCE Drive Beam Generation Complex Main Beam Generation Complex
RF Transverse Deflectors CLIC RF POWER SOURCE LAYOUT Combiner Ring 4 pulse compression & frequency multiplication Delay Loop 2 gap creation, pulse compression & frequency multiplication RF Transverse Deflectors Drive Beam Accelerator efficient acceleration in fully loaded linac Power Extraction Drive Beam Decelerator Section (2 21 in total) 100 ms train length - 32 21 2 sub-pulses - 5.7 A 2.5 GeV - 64 cm between bunches 70 ns 2 21 pulses – 180 A - 2 cm between bunches 4.5 ms Drive beam time structure - initial Drive beam time structure - final
CTF3 MOTIVATIONS AND GOALS Build a small-scale version of the CLIC RF power source, in order to demonstrate: full beam loading accelerator operation electron beam pulse compression and frequency multiplication using RF deflectors Provide the 30 GHz RF power to test the CLIC accelerating structures and components at and beyond the nominal gradient and pulse length (150 MV/m for 70 ns) . Drive Beam Injector Drive Beam Accelerator X 2 Delay Loop X 5 Combiner Ring Main Beam Injector Two-beam Test Area 3.5 A - 1.4 ms 150 MeV 35 A - 140 ns 150 MV/m 16 structures - 3 GHz - 7 MV/m HIGH POWER 30 GHz TEST STANDS RF DEFLECTORS
FIRST “FULL” BEAM LOADING OPERATION IN CTF3 SiC load Damping slot Dipole modes suppressed by slotted iris damping (first dipole’s Q factor < 20) and HOM frequency detuning RF power 1.5 ms beam off beam on RF signals / output coupler of structure 30 MW 0.4 MW Beam current 4 A Beam pulse lenght 1.5 ms Power input/structure 35 MW Ohmic losses (beam on) 1.6 MW RF power to load (beam on) 0.4 MW RF-to-beam efficiency ~ 94%