Shield wall build in Area 2
Shield wall build in Area 2

Tower Civil and Engineering Work for ERLP

The ERL prototype will be sited in the Tower Areas 1 and 2, which were formerly used for experiments on the Nuclear Structure Facility. The 1m thick concrete walls of the building were perfectly adequate shielding for the NSF heavy ion beam accelerator but 1.5m of concrete shielding together with local steel or lead shielding is needed for the ERL Prototype. In fact a 2m of concrete solution, constructed from old NINA shielding blocks, has been adopted. The extra shielding thickness will provide some contingency, operational flexibility and significantly reduce the local shielding required. Reuse of the NINA blocks has also significantly reduced the project shielding costs.

Engineering solutions to service entries and personnel access labyrinths are also now well defined and 90% of the internal shield wall build is complete. This has involved moving in excess of 2000 tonnes of shield blocks from the block compound into position. Strengthening of weaknesses in the shielding caused by the old service ducts to the basement is also complete.

Civil work on the foundations to support the external labyrinths will start in July and further block wall construction work will continue to late autumn.

Specification and design work on the laser and control rooms is near completion and civil construction work has started.

Corrigendum - 27/07/04

Report of the approval of the MCRTN in Newsletter No.2 has proved to be premature. In fact the FELCHA network proposal is currently on the reserve list for funding.

www.4gls.ac.uk

EuroFEL Bid TOPS the list

The 4GLS team have been successful in attracting EU FP6 Design Studies funding as key participants in ‘EUROFEL’. In total Euro9M has been approved for work to run for three years starting in April 2005.

EUROFEL is a collaboration between the European laboratories presently involved in linac-based light sources and is divided into six design study packages each of which addresses a technology issue relevant to the design or operation of such a facility. CCLRC departments, ASTeC, CLF, SRD and Engineering and Instrumentation Department and Strathclyde University are all involved in the design studies. CCLRC is leading the package on Beam Dynamics.

The range of packages, with CCLRC’s contributions in brackets, are:

In parallel with design and construction work on the ERL Prototype, underpinning physics studies are required to address the technological challenges of 4GLS and some of this work will be performed under the umbrella of ‘EUROFEL’.

PROGRESS ON THE PHOTOINJECTOR GUN

The team in the workshop is making excellent progress with the manufacture of critical gun components. Machining of the cathode ball is complete and the delicate task of hand polishing it to a surface finish of better than 1m m is about to start. The large size of the photo-cathode gun is apparent from the size of the cart now fully built in the stores building. This is used during assembly of the cathode body and whilst mounting it onto the anode frame (which is itself nearing completion). Also on view in the stores area is the gun baking oven. It is essential to be able to bake the gun assembly so that XHV (eXtremely High Vacuum, better than UHV) pressures can be achieved.

Top view of Cathode ball
Top view of Cathode ball  		 Bottom view of cathode ball  
Bottom view of cathode ball
Extractor Cart side view
Extractor Cart side view 		Gun Mounting frame
Gun Mounting frame

Although most of the critical items are being made in the workshops, a number of vacuum vessels have been sent out for manufacture. One of these is the cathode vacuum vessel, delivery of which has been delayed by problems. However, these were discovered quickly enough not to affect the photo-injector milestones. Pre-manufacture tests for the 150MW conditioning resistors have been completed, components ordered and delivery will be in about ten weeks.

Bake out oven
Bake out oven

Conditioning resistor manufactured items
Conditioning resistor manufactured items

Cathode components manufactured by the workshop
Cathode components manufactured by the workshop

Extractor cart and mounting frame assembly
Extractor cart and mounting frame assembly

The manufacture of the gun ceramic is progressing more slowly and receiving a lot of attention. This specialised ceramic is extremely large and taxing the ingenuity of the manufactures. It is a critical path item for which delivery is anticipated in November.