LC-ABD L inear C ollider – A ccelerator and B eam D elivery Roger Barlow PPARC: UCL 2nd October 2002

LC-ABD Roger Barlow 2 Oct 2002LC-ABD PPARC SoI Slide 2/10 The Challenges The control of increasing facility costs needs intellectual input. The need for new capabilities in pushing forward the frontiers in the various sciences demands involvement by those who best understand these capabilities.” Maury Tigner, Cern Courier May 2002 “There are two excellent reasons for the stakeholders in these fields to take a more active role in this part of instrumentation development. Accelerator Science needs more brain power

LC-ABD Roger Barlow 2 Oct 2002LC-ABD PPARC SoI Slide 3/10 The components Forum Umbrella organisation Basic Technology bid FONT Laserwire LiCAS Computation Coherent Radiation Electro-Optic Sensing LC-ABD

Roger Barlow 2 Oct 2002LC-ABD PPARC SoI Slide 4/10 FONT Keep beams colliding – feedback applied to the other beam. Essential to get luminosity – beam bunches nm across UK leading in design of vital LC component Tests at SLAC Bid submitted Feedback On Nanosecond Timescales

LC-ABD Roger Barlow 2 Oct 2002LC-ABD PPARC SoI Slide 5/10 LiCAS Phase I Measure collider component positions during installation. (Current technology cannot do this.) Techniques: FSI (frequency Scanning ) with Telecommunications lasers and fibre amplifiers Laser Straightness monitors Spec: 200 micron 3D absolute position over 600 m segments Close collaboration with DESY (MOU) for test and use in TESLA FEL. Technique applicable to all LCs Bid submitted to PPRP (  £70K) Phase II Online monitoring of collider component positions Techniques: Phase I + Michelson interferometry Spec: Phase I with differential measurements  nm and absolute measurement to 100  over 600 m

LC-ABD Roger Barlow 2 Oct 2002LC-ABD PPARC SoI Slide 6/10 Laserwire/Simulation Bunch Profile monitor – needs to be accurate and non-destructive and fast and reliable Hardware development. Tests at CERN & DESY Geant4 simulation in accelerator codes Investigate feasibilty of Shintake beam size monitor – uses laser interference pattern Developments have had support Working with RAL laser group Bid for continuation submitted

LC-ABD Roger Barlow 2 Oct 2002LC-ABD PPARC SoI Slide 7/10 Computation Many questions – new computing techniques and facilities (Grids, Beowulf 2) available for exploitation. Needed as simulation becomes complicated (non-linear, many- body) Liverpool and Manchester+ASTeC Work started – PhD students Want to build infrastructure of accelerator science: courses etc. Bid submitted

LC-ABD Roger Barlow 2 Oct 2002LC-ABD PPARC SoI Slide 8/10 Beam profile studies (1) Bunch passing periodic structure  Smith Purcell Radiation (far I- R) Coherent enhancement for  z Tested at Frascati with 14ps bunches Bid in preparation  £245K over 4 years George Doucas (Oxford)

LC-ABD Roger Barlow 2 Oct 2002LC-ABD PPARC SoI Slide 9/10 Beam profile studies (2) Electro-optic sensors: Birefringent Crystal affected by beam pulse, sampled by laser Sensitive at subpicosecond level Tested at FELIX Free Electron Laser Bid in preparation  £600K Allan Gillespie (Abertay)

LC-ABD Roger Barlow 2 Oct 2002LC-ABD PPARC SoI Slide 10/10 Conclusion Accelerator science is a priority Needs university involvement in R&D as well as major commitments to CLRC machine builders LC-ABD groups committing time, people, effort PPARC support is and will be needed