Transcript ILC Program discussion

ILC Program discussion
M. Ross 14.09.2004
TTF2 -
long term schedule
Modul status
Plans for production
(Hans Weise and Bernd Petersen – TESLA Coll.
Technical Board meeting, 07.09.2004 – last week)
SLAC involvement
Schedule until 2007
Saturation in wavelength range 30-120 nm
July 2005
User operation (extended period)
Operation with long bunch train
Dec. 2005
User operation (extended period)
3rd Harmonic RF system and ACC6 installed
Feb. 2006
1 GeV beam energy
April 2006
(total 48 cav ~=meters)
Saturation 6 nm
June 2006
User operation (extended period)
Seeding Option installed
Dec. 2006
Seeding demonstration
April 2007
https://ttfinfo.desy.de
The TTF electronic logbook
Schedule looks like being FEL dominated. Is this true?
For 2005 we assume
9 weeks of FEL user operation
2 months FEL studies
2 months accelerator studies (diagn. etc.)
includes photon diagnostics
2 months of dedicated acc.module tests
This means: 4 months to be discussed
A must:
- HPP of the relevant cavities M5/C6, M1/C8(?). Others ???
- long time operation of M5 at high gradients in steps from 20
MV/m to 25+MV/m:
- what are the typical problems?
- any change in dark current?
- how close can we go to the gradient limit?
-processing behaviour after interruptions / shut down
The individual modules
ACC1(M2*) HPP of C7.(Z53)
if not successful, attenuator in order to get 4x15MV/m and 4x20MV/m average
ACC2(M1*) optimze attenuators of cavities C1, C2, and C6 so that we get 22MV/m average
ACC3(M3*) HPP of C7 (S28)
ACC4(M4)
measure Qo / Eacc between 15 and 24MV/m
long time operation at highest possible gradients incl. measurement of dynamic losses at
2K, 4K, and 40/80 K
ACC5(M5)
dark current measurement C6 (AC77) -> HPP -> dark current
if required, attenuator C6
attenuator for C8 (AC60 limits module at 25MV/m
measure Qo / Eacc between 15 and 28/30? MV/m average
long time operation at 25MV/m and at max. gradient incl. measurement of dynamic losses
at 2K, 4K, and 40/80K
==> at gradients >15MV/m we never measured the dyn. losses of a complete module at 4k and 40/80K
ACC6(M6)
8 EP-cavities at 35MV/m
8 modified tuners with piezos
2K-magnet
In General
- develop robust algorithm for Lorentz force compensation and test with
piezo tuners at M6 and M1/C5.
- failure recogination and exception handling, esp.close to performance
limit
- measurement and optimization of amplitude and phase stability
(within bunch train, from train to train, long time)
- automized operation (FSM) of LLRF
- test next generation of LLRF (developed for XFEL: increased ampl. and
phase stability requirements)
- beam based feedback algorithms (energy, phase, bunch length)
Cavities @ ACC1
Module 2*
EP cavity
35
Cryostat tests:
Vertical
Horizontal
Module
25
Module
EACC [MV/m]
30
20
15
FE
10
5
0
1 - Z54
2 - Z51
3 - D42
4 - D37 5 - AC72
Cavity
6 - C47
7 - Z53
8 - AC69
23.04.2004
Cavities @ ACC2
Module 1*
Cryostat tests:
Vertical
Horizontal
Module
35
25
Module
EACC [MV/m]
30
20
15
10
5
0
1 - S31
2 - C44
3 - C46
4 - S36
5 - D2
Cavity
6 - A18
7 - D1
8 - A17
5.11.2002
Cavities
@
ACC3
Module 3*
35
30
Couplers conditioning was not completed before the
module measurement : coupler 4 vac.valve was closed.
Conditioning completed later. During Module 3
disassembly couplers antennae touched cavity surface.
Module
25
20
BD
15
10
coupler
EACC [MV/m]
Cavity tests:
(CW)
Vertical
Horizontal (10Hz)
Module 3 (10Hz)
O
Module 3* (5Hz)
O
FT 500+100s
5
0
1 - D41
2 - S32
3 - S29
4 - S30 5 - AC58
Cavity
6 - D40
7 - S28
8 - Z50
14.09.2003
Cavities
@
ACC4
Module 4
Cavity tests:
Vertical
(CW)
Horizontal (10Hz)
Module 4 (5Hz)
35
BD
BD
BD
Module
EACC [MV/m]
25
BD
30
20
15
10
5
0
1 - C48
2 - S34
3 - AC57 4 - AC56 5 - AC55 6 - AC59
Cavity
7 - Z52
8 - AC64
01.06.2004
Cavities
@
ACC5
Module 5
30
dark current src
BD
35
Cavity tests:
Vertical
(CW)
Horizontal (10Hz)
Module 5 (1Hz)
Module 5 (5Hz)
EACC [MV/m]
25
20
15
10
5
0
1 - AC62 2 - AC61 3 - AC65 4 - AC66 5 - AC79 6 - AC77 7 - AC63 8 - AC60
14.09.2003
Cavity
Cavity preparation
general comments
After several technical problems: EP is working now reliably
General assumptions for schedules:
no 1400 C treatment of new cavities
Requirement for next modules: 35 MV/m for each cavity
Assumption for the schedules: Each second cavity will reach
35 MV/m ( this is also assumed for retreated cavities) with
reference to latest experience
CHECHIA test for each cavity
Modul 6 needs cavities out of the new ZANON production
Not yet considered in the schedules:
Clean room will need 3 weeks of maintenance/repair in the next
months
Performance of some Cavities EP re-treated at DESY
(already limited performance after BCP )
Cavity
Eacc before EP
Eacc after EP
1b8
28
33,59
1s2
31,5
1ac 2
+120 C baking
Q0 @23,5
limit
38
1,7E10
BD
31,5
36,6
1,5E10
BD
34,8
31,5
40,5
1,7 E10
BD
ac 78
15,3
-
23,7
2,9E10
BD
ac 78
20,7
15
-
1,7E10
BD
p-1
0,5
10,6
-
7,6E8
Power
p-1
10,6
25,3
-
1,4E10
BD
ac 70
19
30
39,4
1,7E10
BD
ac 80
0,5
27,5
-
1,7E10
BD
ac 80
27,5
28
-
1,6E10
BD
31,5
29
1,2E10
FE
28
19,8
6E9
BD+FE
ac 71
ac 74
Next cryomodules
Modul 6 : ‚high gradient module‘, all cavities 35 MV/m, type III
design:
Ready : May 2005
Modul 7: ‚ linac spare module‘, type II design
TESLA meeting at ZEUTHEN -> all cavities EP treated, 35 MV/m
Helium vessel of type III have to be produced !!! -> decision
needed
(type II cavities& vessels available, flanges have to be exchanged)
Ready : December 2005
Schedule Module 6 (Axel Matheisen)
Cryomodule parts
Tuners: ( at present no piezo tuners available !!!)
Mechanical parts for 17 tuners on DESY site ( incl. 2 ‚mirrored‘)
To be delivered this week:
16 control units + 12 motors
Another 7 motors will arrive in about 3 weeks from now
Magnet packages:
1 TTF-design package ready on DESY site ( + 1 Sstruct)
1 TESLA-design coil will be delivered to DESY in October 04
(TESLA-design package can be used in modul 6 without BPM)
BPMs : ??? 2 old TTF-type available
Main couplers ( 40 ordered): type III couplers for module 6 at Desy,
30 DESY type III couplers will be delivered to Orsay until end of this
year
Cryomodule parts (cont.)
modules beyond 6 &7
modules
cavities
Cold
mass
+ vvessel
tuners
magnets
Hevessels
Total
Availabl
e now
30
1 type II
1 type
III
17
2 TTF
1 TESLA
20 type
III
6
7
Old?
8
9
2
Sstruct
BPM
40
piezos
?
piezos
8 II ?
XFEL
Type ?
4
XFEL-type
8
?
Main Couplers
Single Module Test Stand
( Yury Bozhko –MKS1-)
Some details:
Cryogenic equipment:
After EU call for tender now in the process of making contracts
RF-equipment:
Modulator, puls-transformer on DESY site
Klystron ordered, will be delivered in 2005
Call for tender for wave guides etc….
Civil engineering:
Final specifications ready, procedures prepared and will be started now
Single Module Test Stand (Yury Bozhko)
First operation / commissioning: November 2005
SLAC participation in TTF2 program – discussions from the Orsay Tesla
collaboration meeting
1) Our near-term program is to commission the longitudinal phase space
monitor – transverse cavity ‘LOLA IV’ and provide long term tools that
facilitate its use.
2) We proposed SLAC participation at TTF2 for the following (basically in
response to informal ‘feelers’).
1) HOM signals for position measurement
2) Cavity dark current
3) Optical fiber-based stable RF distribution
4) Beam – based alignment
3) Less formal discussions were held on:
1) Beam phase monitoring
2) Hardware development – power supplies
3) LLRF (commissioning and learning)
4) There is an operating laserwire in the PETRA ring – (RHUL/DESY/Oxford)
Each one deserves a thesis in itself – some are critical
for LC design / construction
Transverse deflection cavity studies
1. Goal:
•
Prove the device for measurement of ultra-short bunch length, energy
correlations and transverse slice emittance
•
Precision, calibrated tool for complex physical process
•
Vital for FEL and LC
•
Develop the application software to facilitate its use
•
Beam dynamics tests of CSR-generated emittance growth
2. Resolution:
•
10um σ_z (30fs) (50m β, 600MeV)
•
Vertical kick allows measurement of Є_x vs z, δ vs z on different screens
3. Study of incoming correlations – ‘pitch’ angle
Martin Nagl, Holger Schlarb, Karsten Klose
Higher Order Mode studies
1. Goal:
1. Prove use of HOM for cavity beam position absolute measurement
2. Develop system for HOM use to minimize wakes and emittance growth
3. Cavity / cryomodule fab / assy alignment test
2. Resolution
1. ~50μm
2. Offset / phase shift caused by coupler location(s) ~150 μm depending on
which mode (Dohlus)
3. Test / compare beam – based alignment using quad shunt
Nicoleta Baboi, Rita Papparella, Olivier Napoly
Dark Current Studies
1. Goal:
1. Measure on axis (up / down) cavity dark I over long term
2. Build, install and equip (controls and signal processing) simple single cell
external cavity
2. Resolution
1. ~1 nA accuracy for each module
2. (30pA is thermal limit with moderate shunt impedance)
3. There is no precision dark I monitor in Checchia (single cavity horizontal test
stand) – recent measurements use radiation monitors
1. Vertical test stand coupler/valve geometry precludes their use
Hans Weise and Manfred Wendt
Stabilized – optical fiber RF distribution
1. SLAC equipment donated to TTF (was unused at SLAC)
1. Fiber, fiber stretcher, xmit/receive, fiber couplers
2. Student project to use this hardware (+ much more needed) to build a stabilized
link.
3. ~100fs / multi-km stability (200 fs demonstrated in 2001)
1. FEL requirements are much tighter – but for somewhat shorter distances
(20fs / 1 km – 5e-9)
Henning Weddig / Stefan Simrock / students