Status and Plan of GDE Design Work (Including Road Map for RDR) Feb.

Report
Status and Plan of GDE Design Work
(Including Road Map for RDR)
Feb. 17 2006
PAL
Eun-San Kim
ILC Meetings
 Snowmass, Colorado, 14-17 Aug. 2005
: Started BCD
 European GDE meeting, Oxford, 25 Oct. 2005
 Damping ring workshop, CERN, 9-11 Nov. 2005
 GDE meeting, Frascati, Italy 7-9 Dec. 2005
: Decided BCD
 1st Area System meeting, KEK, 19-20 Jan. 2006
: Discussed machine layout and boundary between area systems
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Lattice design meeting, CERN, 6-8 Feb. 2006
2nd Area System meeting, FNAL, 13-14 Feb. 2006
GDE meeting, Bangalore, 9-11 March 2006
3rd Area system meeting, DESY, April 2006
GDE meeting, Vancouver, 19-23 July 2006
GDE meeting, Valencia, Autumn 2006
Frascati GDE Meeting
 Discussed progress since Snowmass
 Finally agreed BCD to be documented.
- includes baseline and alternative designs
 Organized the GDE group for RDR in 2006
 Final BCD becomes property of CCB in early
2006
Frascati GDE Meeting
BCD layout
IP
 Working Group for BCD
WG1 : LET beam dynamics
WG2
: Main Linac
WG3a : Sources
WG3b : Damping Rings
WG4 : Beam Delivery
WG5
: SCRF Cavity
Frascati GDE Meeting
Matrix group for RDR
A. Brachmann
M. Kuriki
J. Sheppard
J. Gao
S. Guiducci
A. Wolski
C. Adolphsen
H. Hayano
E.-S. Kim
L. Lilje
P. Tenenbaum
N. Solyak
D. A-K
A. Seryi
H. Yamamoto
Area system is geographical breakdown of
machine for design and cost estimation
1st Area system meeting
Baseline Layout (500 GeV)
- 1st stage : 500 GeV
- 2nd stage : 1 TeV ; Moving of turn-around and BC
No moving of DR
Electron source in BCD
120 keV DC Gun
laser
12 MeV
70-100 MeV
NC
pre-accelerator
NC SHB+solenoid
400 MeV SC Linac
Eacc = 17.8 MV/m
diagnostic section
Positron source in BCD
Undulator ~100m
To IP
e-
Accelerating structure
e+
150 GeV e-
Ti Alloy
Target
To DR
Damping Ring in BCD
 Baseline
e+ : two 6 km rings
e- : one 6 km ring
 Alternative
e+ : 6 km, 17 km
Baseline
DR Tasks List for RDR
 Lattice design
- 6 km e-/e+ rings : L. Emery, A. Xiao, E-S Kim, Y. Sun
- 17 km e-/e+ rings : Y. Cai, Y. Yan
- Injection and extraction lines : A. Wolski
 Acceptance : Y. Cai, Y. Yan, A.Wolski
 Low-emittance tuning : J. Jones
 Impedance : M. Venturini, K. Bane, S. Heifets, etc
 Electron-cloud : M. Pivi, C. Celata, K. Ohmi etc.
DR Tasks List for RDR
 Ion-effects
: L. Wang, E-S Kim, K. Ohmi, M. Venturini, G. Xia
 Other collective effects
: S. Mtingwa, M. Venturini, S. Santis, A. Wolski
 Injection/extraction kickers : pulser
: J. Urakawa, T. Naito, M. Ross, A. Krasnykh, etc
 Injection/extraction kickers : striplines
: A. Krasnykh, S. Santis, D. Alesini, F. Marcellini
Baseline Damping Ring
Circumference
Energy
RF frequency
Harmonic number
Damping time
Emittance
Bunch length
Energy spread
Momentum compaction
Damping wiggler peak field
Damping wiggler period
Energy acceptance
Dynamic aperture
6.6 km
5 GeV
650 MHz
14402
< 25 ms (e+) < 50 ms (e-)
5 mm
6 mm
< 0.13 %
4x10-4
1.6 T
0.4 m
< 0.5 %
Ax+Ay < 0.09 m-rad
Baseline Damping Ring
Bunch filling patterns for e-
Fast-ion effects in Baseline Damping Ring
650 MHz,
5400 bunch
Sqrt(Jy)
Beam size
per 50 turns
Lattice Design of Electron damping ring
One straight section
One Arc and Wiggler section
A lattice with low average beta-functions to reduce the effects of fast-ion.
Tele-conference for e- DR lattice will be at the beginning of March.
Ring to Main Linac (RTML)
Status and Plans
 Started works for shorter bunch compressor
and turn-around optics
 Contacted leaders of all technical and global
systems
 Milestone
- Review RTML design and place lattices and
documentation under change control in April
2006
Ring to Main Linac (RTML)
RTML Layout
Anamorphic Diagram of RTML Footprint
60
Skew Correction
Collimation
DR Stretch
Turnaround
Spin Rotator
Emittance
BC1
BC2
Linac Launch
50
40
X Position [m]
Turn around
eny = 0.02 mm,
30
20
3.2 nC,
sz = 6mm
Total 2.5 km
10
0
SR
-10
-1800
-1600
BC 1
-1400
-1200
BC 2
-1000
sz = 0.15 mm
-800
-600
Z position [m]
-400
-200
0
200
Ring to Main Linac (RTML)
Bunch compressor
Alternative
Baseline
Chicane
68.4 m
480 m
Matching
4m
310 m
Number of RF cavity
452
488
Total length
680 m
1400 m
Alternative
Baseline
Required bunch
length
achieved
achieved
System length
shorter
longer
Tolerence of
emittance
acceptable
comparable
BCD
GDE
Requirement
alternative
correction of
vertical dispersion
acceptable
comparable
baseline
shorten
system length
Ring to Main Linac (RTML)
Bunch compressor
 Each BC in baseline has 240 meters of bend
magnets arranged in chicanes : Long !
 Considering two approaches to reduce length
– Enhancing R56 by forcing nonzero dispersion at Qs
– Replacing wiggler with 4-bend chicane with optimized
lattice functions for emittance preservation
Main Linac in BCD
 Baseline in 1st stage
- TESLA cavity type
- Operation gradient = 31.5 MV/m, Qo=1010
 Baseline in 2nd stage
- LL or RE cavity type
- Operation gradient = 36 MV/m, Qo=1010
- Total length = 41 km
 Alternative in 1st stage
- LL or RE cavity type
- Operation gradient = 36 MV/m
 Linac RF basic unit
- 1 modulator, 1 klystron, 3 cryomodules, 27 cavities
Beam Delivery System in BCD
 Baseline :
- 2 IPs for 2 mrad and 20 mard
- 150 m longitudinal separation between 2 IPs
 Alternative :
- 1 IP
Summary
 Bangalore GDE meeting
- starting for estimation of costs
 RDR will be finished in Dec. 2006
- RDR is not complete technical design,
but is a design to estimate reliable cost.
 TDR will be completed in Dec. 2008.

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