CEA-Saclay Activities - TESLA Technology Collaboration - Desy
CEA-Saclay Activities - TESLA Technology Collaboration - Desy
CEA-Saclay Activities - TESLA Technology Collaboration - Desy
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
<strong>CEA</strong>-<strong>Saclay</strong> <strong>Activities</strong><br />
• CARE / SRF<br />
– Suface Preparation - Electropolishing<br />
– Cold Piezo-Tuners<br />
– Horizontal cryostat CRYHOLAB tests<br />
– Cold reentrant BPM<br />
• TTF2 : Beam loss electronics<br />
• TTF2 : HOM<br />
• EuroTeV : Collider design<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 1
CARE-SRF : Surface Preparation - EP<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 2
CARE-SRF : Surface Preparation - EP<br />
Electropolishing of single-cell cavities<br />
• Single-cell EP Set-up, purchased from CERN<br />
• Installation and upgrading is underway<br />
• Commissionning in <strong>Saclay</strong> foreseen early 2005<br />
5.- EP on single cell<br />
5.1.1 EP on samples<br />
5.1.1.1 Establishing method of surface characterization<br />
(roughness, reflectometry)<br />
5.1.1.2 Surface characterization fixed<br />
5.1.1.3 Series of EP with samples for surface investigation<br />
5.1.1.4 Best EP parameters<br />
5.1.2 Single cell cavities<br />
5.1.2.1 Order Nb and fabricate 3 cavities<br />
5.1.2.2 3 cavities fabricated<br />
5.1.3 EP chemistry on single cells<br />
5.1.3.1 Design of EP set up<br />
(90%)<br />
5.1.3.2 Fabrication of EP set-up<br />
5.1.3.3 Commissioning of EP set-up<br />
5.1.3.4 First operation of EP set-up<br />
5.1.3.5 Operation of EP set-up<br />
(30%)<br />
(50%)<br />
(20%)<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 3
CARE-SRF : Surface Preparation - EP<br />
Series of EP with samples<br />
• Gloss measurements allow fast evaluation of surface state<br />
• No correlation between etching rate and surface state<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 4
CARE-SRF : Surface Preparation - EP<br />
Rotating sample holder<br />
@ 16 V :<br />
• t = 470mn, d A-C<br />
=22 mm,<br />
Rem.Thick. = 160 µm<br />
• t = 470mn, d A-C<br />
= 92mm,<br />
Rem.Thick. = 80 µm<br />
EP bath<br />
• t = 300mn, d A-C<br />
=2.2mm,<br />
Rem.Thick. = 157 µm<br />
• Standard sample holder<br />
Rotating sample holder:<br />
(reproduces cavity<br />
geometry, exposure to air,<br />
rotation….)<br />
• Rotating anode: surface state differ considerably from what usually found<br />
on samples => better tool to estimate optimal conditions on cavities<br />
• Several bath compositions will be tested with design of experiment<br />
techniques (statistical tool => modelisation of the behavior of any bath<br />
composition)<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 5
Surface Preparation<br />
Other activities : Replica @ the quench site<br />
a) b) c)<br />
Contour line of replicas, modelling of the edge profile and β (field<br />
enhancement factor) for a) first quench site, b) same area after 20 µm<br />
etching, c) new quench location.<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 6
CARE-SRF : Cold Piezo Tuner<br />
•Old design : last batch of 16+3 tuners sent to DESY<br />
•New design of cold tuner: pre-study finished<br />
includes 2 piezos<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 7
CARE-SRF : Cold Piezo Tuner<br />
New design of cold tuners with:<br />
• SOLEIL upgrades<br />
• larger rigidity<br />
• Fabrication of 2 tuners (beginning of 2005)<br />
• 12 NOLIAC piezos, 2 PHYTRON stepping motors ordered<br />
• Coll. with IPN Orsay: <strong>CEA</strong> send NOLIAC piezos to IPN for<br />
characterization, and IPN send P.I. piezos for tests on tuners<br />
• Coll. with INFN-Milano for measurement with stress sensors @ 2K<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 8
CARE-SRF : Cold Piezo Tuner<br />
New design of cold tuner<br />
The preload on the piezos is defined by the cavity<br />
compression strength, therefore by the cavity frequency<br />
tuning:<br />
1 - before chemical treatment (field flatness)<br />
2 - pre tuning before cooling<br />
Rough estimation on the uncertainty of the preload<br />
value at cold from 300 N to 2000 N<br />
(« optimum » preload for the piezo NOLIAC ~ 600N)<br />
⇒ Need to optimize the frequency tuning<br />
⇒ Integrated Cavity Tests in CRYHOLAB<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 9
CARE-SRF : CRYHOLAB tests<br />
Adaptation :<br />
cavity handling<br />
and support<br />
Preparation : → April 2005<br />
1 st series (Magnetostrictive & <strong>CEA</strong> tuners): summer 2005<br />
2 nd series ( IN2P3 activity – LAL coupler) : spring 2006<br />
3 rd series ( INFN tuner ) : autumn 2007<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 10
Cold Reentrant BPM<br />
Measurements in ACC1<br />
(D. Noelle, M. Wendt)<br />
• Raw signals (measured directly<br />
with an oscilloscope at the output<br />
cables) are clean.<br />
• (Analog) electronics will be<br />
connected next month.<br />
New cavity design<br />
• A new reentrant cavity will be<br />
fabricated with some changes<br />
(easier cleaning, mechanical<br />
interfacing).<br />
• Reliability of feedthroughs during<br />
thermal cycles will be improved.<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 11
Beam Loss Electronics<br />
TTF 2 beam loss protection electronic board<br />
BIS<br />
Upstream<br />
Downstream<br />
Toroids<br />
<strong>TESLA</strong> collaboration meeting -LAL Orsay<br />
07/09/2004 12
Beam loss Electronics<br />
Beam Tests on (T1-T2) toroids across ACC1<br />
SACM/LESAR / September 2004 - Orsay<br />
07/09/2004 13
Amplitude [dBm]<br />
−25<br />
−30<br />
−35<br />
−40<br />
−45<br />
−50<br />
−55<br />
−60<br />
HOM (coll. with DESY)<br />
Beam Measurements on ACC1<br />
• Studies on alignment in the <strong>TESLA</strong> cavities based on<br />
the signals from the HOM couplers started on ACC1<br />
Dipole<br />
passband<br />
1 (TE-like)<br />
2 (TM-like)<br />
Cavity 1, HOM coupler 1<br />
Passband 1, mode #6<br />
Pol. 1: 1703.363 MHz<br />
Pol. 2: 1704.223 MHz<br />
Mode #<br />
6<br />
7<br />
4<br />
5<br />
Frequency<br />
(simulation) [MHz]<br />
1713.7<br />
1738.3<br />
1864.7<br />
1872.7<br />
R/Q<br />
[MW/m 2 ]<br />
11.21<br />
15.51<br />
6.54<br />
8.69<br />
Polarisation axes<br />
randomly oriented<br />
in the transverse<br />
plane<br />
1.703 1.7035 1.704 1.7045<br />
Frequency [GHz]<br />
SACM/LESAR / September 2004 - Orsay<br />
07/09/2004 14
HOM (coll. with DESY)<br />
Beam Measurements on ACC1<br />
• Beam based alignment resolution of 50 µm w.r.t.<br />
cavity HOM axes<br />
Cav.: 1, Passb. 1, mode #6, Pol. 1<br />
Cav.: 1, Passb. 1, mode #6, Pol. 2<br />
y<br />
HOM Ampl. [a.u.]<br />
20<br />
15<br />
10<br />
5<br />
0<br />
x = −1.75 mm<br />
1→2<br />
a<br />
←y = 0.766 mm<br />
−2 −1 0 1 2 3<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
y = 0.797 mm<br />
2 →3<br />
b<br />
←x = −4.83 mm<br />
−6 −5 −4 −3 −2<br />
polarization<br />
directions<br />
2<br />
3<br />
5<br />
4<br />
1<br />
x<br />
HOM Ampl. [a.u.]<br />
4<br />
3<br />
2<br />
1<br />
0<br />
2<br />
x = −4.85 mm<br />
y = 0.452 mm<br />
1.5<br />
3 →4 4 →5<br />
0.5<br />
c<br />
←y = 0.441 mm<br />
d<br />
←x = −4.85 mm<br />
0<br />
0.4 0.6 0.8 1<br />
−5 −4.9 −4.8 −4.7<br />
y [mm]<br />
x [mm]<br />
1<br />
SACM/LESAR / September 2004 - Orsay<br />
07/09/2004 15
EUROTeV : Collider Design<br />
<strong>Collaboration</strong> with Daresbury and LAL-Orsay<br />
• New Collimation and Final Focus designs<br />
• New IR design with crossing angle options<br />
IP<br />
QD<br />
QF<br />
2 mrad<br />
Nb3Sn SC quadrupole:<br />
prototype under construction (1m), will be tested in 2T<br />
external solenoid<br />
SACM/LESAR / September 2004 - Orsay<br />
07/09/2004 16