MICE RF – TIARA and General Progress

Tim Stanley RAL5 June 2013

RF Amplifiers - Testing

• Aim: achieve 2 MW at Daresbury Lab before transfer of the TIARA system to RAL

• Previously achieved:Just over 1 MW achieved last Autumn.

• Current position:– False trips of protection circuit (crowbar) in PSU;

limits supply voltage to RF amplifiers.– Diagnostic tests over the last few weeks.– Replacement with re-used crowbar device (thyratron)

gave some improvement; further conditioning and+ trials to recommence tomorrow at Daresbury Lab

– High-spec thyratron available from Strathclyde University (circuit mods required) might enable RF testing programme to resume up to 2 MW

– Best long-term solution is probably to procure solid-state crowbar devices. (8-weeks delivery and dependent on budget).

RF testing:Once crowbar issue is fixed, main task is to

optimise tuning of the end-stage tube amplifier at/for high power; an iterative process.

TIARA System

TIARA System

TIARA Preparations for Installation

• Draft drawings have been produced, TS and AN at DL tomorrow to discuss detail

• Modifications to mezzanine floor have commenced

• Safety Document generated by RF group and being ratified at RAL. TS to be appointed EMF Protection Advisor.

• De-mineralised cooling water system defined and drawn; interface/control panel to be built, and tested on TIARA amplifier system at DL before installation in MICE hall at RAL.

• Water supply, of sufficient spec for TIARA, is currently available in MICE hall.

• a local water-monitoring and protection circuit is advisable for TIARA until the full control system is installed.

• trigger-generation unit required for timing of RF pulses in absence of LLRF full control system.

• On-site supply of electricity: No remedial work expected until 2017; this might not even incur interruption of supply

• Compressed air for amplifiers: layout/routing yet to be finalised.

• Pressurisation (nitrogen gas) of co-ax transmission-lines, to dummy-load, is not necessary for TIARA RF milestone.

Procurement – Full System

• Substantial procurement of RF components through University of Mississippi– New Tetrode amplifier set delivered to University of Mississippi from

Photonis.– 4 new tetrode valves ordered from Photonis– Loads on order from Altronics.

• Distribution Network– RF 4” elbows delivered to U. Mississippi– Order placed for all other required co-ax components with Mega;

numbering/ID system implemented and deliveries have commenced.– Orders for 2 additional capacitors for RF system 2 placed with GA.– Capacitor chargers ordered from Lambda– List of support equipment being prepared, including

• Solid state replacement for crowbar.• RF test gear• SSPAs

– Don Summers (and colleagues) working on procurement; latest update: components for tuner-system ordered ($150K)

• All major components required for TIARA deliverables ordered.