Olivier Brunner, on behalf of RF/MK.

RF/MK: 2013 in a nutshell

Installation: equipment, waveguides, water cooling, local cabling Upgrade of LEP equipment Contract follow up: new klystrons, spare circulators Reliability is a key issue here: RFQ commissioning, phase adjustment

Linac 4 – HPRF system installation and commissioning

• WR 2300, L = 1500 mm, r1=70mm, r2 = 40mm • VSWR ≈ 1.2 [depth 0 -> 100 mm]• S11 ≤ -30 dB [depth 0 -> 90 mm]• Range: ≈ max 60˚

Developments

phase adjustment / phase tuners graphic user interfaces (GUI)

D. Glenat

System performed very well: Did not limit the evolution of peak or integrated luminosityBetter performance than in 2011

Some “weaknesses” have been identified

To do list• 8 klystrons replaced (new boilers + age profile)• HV bunkers equipped with new air cooling systems• New klystron heating system• Oil tests and reconditioning• HV cable repair campaign• Thyratron replacement• DCCT and tetrode replacement R&D in progress• Maintenance• …

LHC RF System Operation (ACS)

o Very simple circuito No cooling (±10W)o 90 litters oil volume

o Sophisticate circuito Water/oil Cooling o 350 litters oil volumeo Limited lifetime

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Thyratrons & Solid State thyristors Thyratron n°1914

Thyratron n°2827

Switch n°4 A5 triggerMA2622A

Switch n°1 trigger MA2622A

Solid State device has better performances than the thyratron Validated during 2012 running period In series production

Solid state crowbars (“fast protection system”)

Zone with welding defect

Klystron filament glitches responsible for frequent RF trips during operation Procedure validated to re-weld the connectors without damaging the insulation material Campaign in LHC will soon be launched

Repair of the high voltage connectors

Zone with welding defect

Equipment used in LHC are no longer produced by industry Development of a FPGA based electronic located in HV modulator Evaluation tests in progress

Digital measurement system for the klystron modulators

Zone with welding defect

Photo-diodeamplifier

Waveguideport

Detectorview angle

Interlock

Waveguidesystem

Optional external logic

Presented at the BE-KT day, June 3rd 2013 Agreement between CERN and an external company (Microstep-MIS- Slovak Rep.) to

transfer the knowledge

A new generation of Arc Detectors for the HPRF systems

Sample Testing with the Quadrupole Resonator

Research Highlight: Slow cooling across Tc

mitigates flux trapping in bulk niobium and reduces its residual losses.

High resolution measurements of the surface resistance

• Testing of models for SRF loss mechanisms• Studies of new materials and niobium treatments

SRF research

Zone with welding defect CTF3 operation (11 S Band and 1 L Band power sources) Thirteen PETS tanks installed and commissioned Full beam transport to end-of-line spectrometer Power produced (70 MW/PETS): fully consistent with expectations Max power produced: 720 MW (12 PETS) Max deceleration: ≈ 36%

CTF3 & CTF3 Test Beam Line (TBL)

TBL line in CLEX

Beam deceleration, measured in spectrometer and compared with expectations

Zone with welding defect

Contract (almost) placed with industry for 1 GHz high efficiency klystron Gun Sub-harmonic buncher Beam dynamics

Drive beam front end developments

Zone with welding defect Xbox1 reliably working for most of the year Two structures successfully tested Test bed for:

LLRF systems Conditioning and breakdown detection algorithm Diagnostic tool development

Xbox1: 12 GHz high gradient breakdown tests

Test Stand produces reliable results comparable to KEK

Zone with welding defect

Xbox2: Second X-band test bench in bld 150 Modulator installed Klystron in validation tests at SLAC Commissioning: Spring ‘14

Preparation of Xbox2

Zone with welding defect

Based on high repetition, low power klystrons Contract for klystron&modulators placed in August (Toshiba) Integration work has started

Next generation of x-band facility: Xbox3

Zone with welding defect

Cavities shipped to: Pakistan, London, Edinburgh, Madrid, Rome, Berlin, Poland, Norway, Hungary,

Denmark, Cern,...

LEP Copper cavities – a new life!

CERN, Bld 182 London Science Museum