drive beam transfer lines in the main tunnel b.jeanneret cern/ab/abp clic workshop, 16 oct 2007
TRANSCRIPT
Drive Beam transfer linesin the main tunnel
B.Jeanneret CERN/AB/ABP
CLIC Workshop , 16 Oct 2007
DB transfer lines, B.Jeanneret, CLIC w'shop 16oct07
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Outline
• Long DB transfer line
• Issues related to turnaround
• Issues around the dump sections
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e+ injector, 2.4 GeV
e- injector2.4 GeV
CLIC 3 TeV
e+ main linace- main linac , 12 GHz, 100 MV/m, 20.85 km
BC2BC2
BC1
e+ DR365m
e- DR365m
booster linac, 9 GeV, 2 GHz or 4 GHz ?
decelerator, 24 sectors of 868 m
IP1
BDS2.75 km
BDS2.75 km
47.9 km
drive beam accelerator2.38 GeV, 1.0 GHz
combiner rings Circumferences delay loop 72.4 m
CR1 144.8 mCR2 434.3 m
CR1CR2
delayloop
326 klystrons33 MW, 139 s
1 km
CR2delayloop
drive beam accelerator2.38 GeV, 1.0 GHz
326 klystrons33 MW, 139 s
1 km
CR1
TAR=120m
TAR=120m
245m 245m
From H.Braun15-oct-07
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Long DB transfer line• Aim : transport the Drive Beam trains from
the central area of the site towards the head of the Main Linac
• Deflect a train in each turnaround, one after the other
24 times
Sector 870 m
~100mQD QF…
Decelerator
Kicker
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A combined magnet for the long TL - I
(borrowed w/o permission from P.Belochitskii, T.Eriksson and T. Zickler,CERN/AT/MEL/2007/TZ, oct 2007)
- Need- Q with GL = 0.25 Tm/m- B h & v for orbit correction- S for chromatic correction- Useful radius : 25 mm
- First pass Ansys for Q :- r_Q_coil_in = 30mm- I=30 A, nI=330 Aturn- wire 9mm^2
- Get (to be refined) :
This exemple contains : Bh, Bv, Q, Qs, S
Yoke diameter 150 mm
Weight 80 kg
Quad power 40 W
B + S power <50 W
Low fields allows for ‘cos(n)’ design
Many thanks to M. Bajko forexpertise and advice
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A combined magnet for the long TL - II
• Compact monolithic & low-weight object,for ceiling installation
• Thin power and cooling lines
• Remains to work-out :
– Detailed design, body field errors– Compensation of end-field errors– Powering ( I vs. V …)– Cooling (air, water)– Overall engineering (reliabilty, cost, …)
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Main tunnel cross-section
Main beamDrive beam
Conflictswith survey,Accesibility,maintenance
EnteringTurnaround
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Turnaround :A first look at integration issues
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Turnaround as of today , F. Stulle/PSI (this w’shop)
Shall we install these elementsin the Main tunnel ?Dipoles : length 1m, section .4x.4 m^2Weight ~ 1 ton
~ 27m
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Turnaround tunnel
• Is it reasonable to hang elements at the ceiling ?– Linear weight ~ 1ton / m– Restricted space for good survey
• Shall we consider a tunnel which is shifted upwards ?
• Optics & layout to be reviewed with civil-engineering constraints
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~2 m
2.25 m
No big/heavy elements here
- Minimize disruptive impact on- main tunnel continuity- ensure turnaround stability- more easy installation ?
Much work ahead
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Drive Beam dumps :A first look at integration issues
Sector 870 m
~100mQD QF… Kicker
DUMP line
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NEW DECEL
View from side
View from top
Dump dipoles, +- 200 mm high
0 2 4 6 81 0-0.2
0.0
0.2
0.4
0.6
0.8
0 2 4 6 81 0-1.0
-0.5
0.0
0.5
1.0
OLD DECEL
NEW DB
Width of DB quads
2.5 GeV
0.25 GeV
SIDE VIEW
TOP VIEW
Spot ~2.5m at 20mon dump
A way to avoid alternating low and high Decelerators – now baseline
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Optics
• Regular FODO identical to DB same Quad/strength
• =2 between dipoles to allow for D=D’ =0 before and after
• Dipoles : – L = 0.6m – = 0.075 mrad– B=1.04 T
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Dump dipoles (with T. Zickler)-- preliminary --
g
c
c
b
ab
b
c
alfa 5.00E-02 radlen 6.00E-01 mp 2.50E+00 gevB 6.94E-01 T
full gap g 3.00E-02 mmuz 1.26E-06I 1.66E+04 wire 1.60E-05rho_i 1.20E+06 A/m2 (4x4 mm2)fill factor 7.00E-01 I wire 1.92E+01full coil_area 1.97E-02 m2coil_block 9.87E-03 m2 turns 8.63E+02coil_side c 9.93E-02 m turn/block4.32E+02
matrix 20.77822B_iron 1.10E+00 T
check 9.93E-02full aperture a 1.50E-01 m (matrix*4mm/sqrt_fill)b_yoke b 9.47E-02
full yoke width 3.44E-01 mfull yoke height 4.18E-01 m
H = 0.35m
V = 0.42m
L = 0.6m, = 0.05 radB = 0.7 TH = V =~ 0.4m
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Common section :Descending fresh DBExit line used DB
Last part ofturnaround
To dump
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Single height DB and dumps
• Two height Decelerator was abandonned
• Single height DB : Space taken from RF/dump : 8.0 m
• Along 10m of each sector, vertical superimposition of entering new DB and extraction of used one.
• Dump line to be designed / more beam simulation needed
• Dump proper must be better known– Container filled with aluminum balls and water– Built in-situ ? Delivered as a single unit ?
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Summary
• Long transfer line– Small compact combined magnet can be considered– Conflict services / beam line / survey must be resolved
• DB Turnarounds– Optics exists– Integration requires more attention and coordinated approach– Civil engineering not trivial
• DB Dump line– Single height decelerator is an overall simplification– But short 10m section with two lines must be studied– Dump line and dump tunnel still to be designed