WP4- chopper

 

TASK OF WORKING PACKAGE 4 : CHOPPER

The next generation of high energy, high power proton accelerators must be designed for very low uncontrolled beam loss. In many cases, the beam from a linac is injected into a synchrotron, an accumulator or a compressor ring, and subsequently extracted. Unless suitable measures are taken to control the dynamics of the beam, both processes can lead to considerable particle loss. Loss-free injection and longitudinal capture can be achieved if the linac bunches are precisely injected inside the synchrotron buckets and no particles end-up outside. Beam loss at extraction may be minimised by ensuring that no circulating beam coincides with the field rise-time of the extraction magnet. These demands may be met by selective elimination of sets of bunches in the low energy stages of the linac by using a fast deflector or “beam chopper”. The field should rise and fall between the beam bunch interval, so that no partially chopped bunches remain in the machine, and this usually has to be within a period of the order of 2 ns.
Specifications for these key components are technically challenging, and programmes have been implemented at CERN and CCLRC-RAL based on the development of slow wave (E-field) transmission line structures and high-voltage, fast-transition time pulse generators. Differences in the programmes ensure that a range of ideas will be investigated and there will be benefits from developing each in parallel over similar timescales. Both approaches rely on two successive sets of meander-line structures, but differ in the functioning of the meander lines, in the performance requirements of the driver amplifiers and in the design of the beam dumps. Prototypes of the slow-wave structures, drivers and the beam dumps will be designed, built and tested with beam.

 

 Working Package Coordinator : Alessandra Lombardi (CERN)

 Participating Institutions : CERN, RAL, CEA and LPSC

 

 


MEETINGS , MINUTES,  AND RELEVANT EVENTS.

· Presentation of WP4 , Nov 03 at CERN

 

 

· First annual meeting of WP4, May 04 at CERN

·  

Programme (you can download the talks from this page)

Highlights and goals for the next year

List of participants

 

· Second annual meeting of WP4, Apr05 at RAL

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         Programme

        List of participants

 

·     Third annual meeting of WP4, May06 at CERN

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            Programme

            Summary of the discussion

            List of participants

 

·       Fourth  annual meeting of WP4, June07 at CERN

·  

            Programme

            Summary of the discussion

            List of participants

                   

                 

 

 

 


contacts :

for WP4 Alessandra.Lombardi@cern.ch

for WEB page Beatrice.Hadorn@cern.ch

 

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