1. on behalf of the RF group
LSS Review - RF
O. Brunner
on behalf of the RF group

2. Summary UX45 – RUX45 Installation
Status & Worries  Interactions with LSS installation
ACS, ADT & APW Equipment Preparation Status
Conclusions

3. 3 RF systems in LSS4: ACS - ADT - APW
APWL – RF
APWT - BI
APW
APWL – RF
APWT - BI
ADT
ADT

4. UX45 – RUX45 Installation Main activities:
Water cooling
Civil Engineering
Cabling
Wave guide installation
Ventilation
 Might affect the LSS installation if planning not respected
By e.g.: UX45-RUX45 cabling=> WG installation => SC modules installation

5. Main worries – 1 (Civil Engineering)
Shielding wall in UX45
Two passages used for QRL installation in the junction regions now being closed
Solution approved by SC/RP: Solid bricks
Problem: Non conform “bricks” used instead
“Solution” proposed by TS/CE: additional layer of bricks
Wall to be rebuilt?
Waiting for SC/RP approval
Main worries:
Might affect LSS installation planning
Wall => Cabling => WG => SC modules
Personal protection during cavity commissioning
Equipment protection (cavity control system will be installed along the wall)

6. Main worries – 2
RUX45 Roof
Roof needs to be partially closed (on each side) prior to SC modules installation:
Roof  RUX45 air cooling units Cryogenic distribution lines to SC modules  (WG)  SC modules
In order to follow up the LSS installation planning
(H. Gaillard):
Roof parts must be ready by beginning of May
Roof installation: mid-May
Ventilation: 8 wks (?)
Cryogenic lines installation 4 wks
SC Modules installation mid-July

7. ACS System Equipment Equipment/Status: 100kV/40A LEP Power Converters:
3/4 already checked by AB/PO
4 HV bunkers (UX45) + equipment (modulators, crowbars, ..):
equipment in preparation. Ready for installation this summer
16 high RF power stations (UX45):
pre-installation in progress at CERN
wave guide system:
60% already mounted. Waiting for end of cabling campaign
4 SC modules (4 cavities each) + 1 spare module:
now being tested and prepared in SM18
will be ready for installation mid-July (as planned) despite all tuning system problems
UX45

8. ADT System Equipment (CERN – JINR collaboration)
Equipment/Status:
All 20 vacuum tanks and supports delivered to CERN
19 tanks & all electrodes cleaned and leak tested
18 kickers assembled (bake out finished by mid-April)
Ready for installation as planned (16 kickers needed by mid-July)

9. APWL – pick ups Equipment/Status: Prototype built & tested
One pick up installed in SPS (reference)
6 LHC pick ups now being built:
Ready by mid-April
Calibration done by mid-May
Bake out finished by mid-June
Ready for installation: end of June
APWT? Built by BI. Late delivery might affect vacuum activities (bake out in particular)

10. Bakeout in LSS4 Bakeout essential ! SC cavities Electronics:
Absorbtion on cold surface from neighbouring sectors (cryo-pumping)
=> Increased dynamic losses, multipactoring
=> Difficult reconditioning after warm-up
In test stands we need 10E-7/ 10E-8 to operate, limited volume (cavity & cut off tubes)
Need better in machine due to larger volume (10E-9..?)
Electronics:
Single event upsets SEUs from beam gas collisions are a concern
Effect proportional to vacuum:
=> With 10E-8 mbar we would have between 10 and 100 SEUs per year in all LLRF systems in UX45 (Rough estimate)
Bakeout essential !

11. Conclusions UX45 & RUX45 Installation RF Systems:
Still many interdependent co-activities
RF Systems:
ACS modules should be ready on time despite many tuning problems discovered recently
ADT kickers: will be ready on time for installation
APW pick ups: will be ready on time for installation
APWT? If late will affect vacuum activities (bake out)