1. 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

2. Linear Collider parameters (from the ILC-TRC/Second Report 2003)
F. Ruggiero
Linear Colliders: ILC and CLIC

3. 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
L1033
[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

4. 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
L1033
[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

5. 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

6. 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  %

7. 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

8. THE CLIC RF POWER SOURCE
Drive Beam Generation Complex
Main Beam Generation Complex

9. 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 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

10. 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 ms
150 MeV
35 A ns
150 MV/m
16 structures - 3 GHz - 7 MV/m
HIGH POWER 30 GHz
TEST STANDS
RF DEFLECTORS

11. 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%