Ongoing & Planned BDS work Deepa Angal-Kalinin ASTeC Daresbury Laboratory (CCLRC)

Ongoing and Planned BDS work in the UK LC-ABD : 3 Years funded programme on BDS by PPARC/CCLRC (Started from April’04) : G. Blair & P. Burrows (PI & PM) 5 work packages Lattice design and simulations (D. Angal-Kalinin) Advanced Beam diagnostics (G. Blair) Alignment and Stabilisation(A. Reichold) FONT + Spectrometry (P.Burrows) Technology (M.Poole) Polarised positron Undulator Crab Cavity Collimation 20 (from 23) new posts have been filled.

Linear Collider Accelerator Beam Delivery (LC-ABD) Project : 14 UK Institutes

EUROTEV 3 years project funded by EU from Jan’05 BDS Diagnostics DR PPS ILPS Metrology & stabilisation GAN All the LC-ABD work packages are contributing. Some additional support requested.

EUROTeV WP2 : BDS Overview WP2 : BDS BDSLDCRABRFFFBKSWMDSCFD Tasks cover critical design choices for the BDS BDS Lattice Design Crab cavity RF system Design Fast Feedback System Design Spoiler Wakefields & Mechanical Design Super- conducting Final Doublet R&D CCLRC CEA CERN CCLRC ULANC QMUL CCLRC CCLRC CERN TEMF UMAN ULANC CEA

Work at CCLRC : Beam Optics ASTeC Accelerator physics group : Linear Collider Studies D Angal-Kalinin Rob Appleby Frank Jackson James Jones (50%) LC-ABD optics post at Liverpool (Crockcroft Institute) Collaborations with J.Payet, O. Napoly, Saclay P.Bambade, B. Mouton, Orsay A. Drozhdin, FNAL N. Walker, DESY

Final Focus Optimisation Set up the local chromaticity correction optimisation procedure MAD+BETA+DIMAD FFS with final quadruplet for the small vertical crossing angle scheme to reduce the beam size of the low energy tail particles in the extraction line Contribution of each higher order aberration to beam size  Lie algebra techniques to understand which aberrations should be minimised (LAMA:N. Walker) Working with J Payet on the global optimisation for FFS design in his code BETA

Collimation Studies Using MERLIN and STRUCT NLCTESLA Frank Jackson NLC and TESLA halos at final doublet (Uniform phase space, 1% energy spread, MERLIN 2 nd order transport)

Extraction Line l*=4.1m m 3m  optical transfer < 2 mrad ~ 6 mrad 1-1.9m to beam diagnostics [R Appleby, P Bambade et al] Studies for the Small vertical crossing angle for ILC extraction line 2 mrad crossing angle extraction line design

Beam optics work plan Extraction line design for 2 mrad, cross check of 20 mrad optics and losses, beam diagnostics (with Andrei, Yuri, Brett, Cherrill) ILC final focus design for different L*, improve TESLA L*=3,4,5m lattices with long drift of 250m to third/higher order (Jacque’s new optimisation code + Andrei’s tools ) for the ILC. Study beam collimation efficiency for the ILC decks using STRUCT and MERLIN. Locations of specialised/generic beam diagnostics devices, required specifications (Energy spectrometer with UCL group) Ground motion modelling Tuning procedures ATF2 optics, tolerances/tuning, upgrade to 1 TeV ESA optics : focussing the beam to small sizes at the collimator location.

Crab Cavity Team Graeme Burt Amos Dexter Philippe Goudket Alexander Kalinin Carl Beard Mike Dykes (RF Group Leader) Mike Poole (WP leader) One more post will be recruited soon at Daresbury + one more post requested at Lancaster from EUROTeV.

Crab cavity Phase stabilization Test System The team is considering which engineering issues can be resolved by the phase stability experiment proposed by J.Frisch.

Crab cavity Issues Position of crab cavities Type of crab cavity Frequency of operation Phase jitter, field stability  Luminosity? Effect of wakefields i.e. cavity harmonics Performance of phase control systems

Spoiler Wakefields and Mechanical Design Simulation code to correctly simulate geometric/resistive wake fields of spoilers, spoiler designs, material damage, validation of simulations against measurements. Specifications of spoilers Material Damage studies Cold test measurements set up Fabrication of spoiler prototypes Development of wake field simulation codes Spoiler beam tests at SLAC test facility (discussions with P.Tenenbaum, Mike Woods, Ray Arnold  N. Watson)

Collimation Programme RF impedance bench tests [Beard, Sopczak, RA, R Carter] Benchmark against known spoiler profile, large taper angle, MAFIA etc. Use cold test results to: Provide data to assist development of improved e.m. modelling in problematic regimes - Also within UK, build up expertise (non-LC applications) - (Within EUROTeV) collaborate with TU Darmstadt Alternative spoiler profiles, (at least) relative performance Theoretical studies [Tucker, Burton, Shales (Lanc.)] Direct beam measurement at SLAC [CCLRC, Lanc., Birmingham] EUROTeV  extend into material damage studies CCLRC Engg Department, Manchester, Birmingham

To summarise…. Ongoing discussions with SLAC on beam optics, tuning, crab cavity, collimation, wake field measurements……. Hope for a strong collaborative work for the ILC in the coming months!

Polarised positron Undulator work at CCLRC : J. Clarke Need a short period more periods more photons more positrons Two competing designs both 14mm period and ~4mm beam aperture: Super-Conducting Bifilar helix Permanent Magnet ‘Ring undulator’

Permanent Magnet Test Module : J.Clarke Magnet block assemblies being manufactured – Due end Jan 05 Other components currently being manufactured at Liverpool Assembly begins February Followed by Magnet Measurements at Daresbury

Positron Undulator : J. Clarke Two test modules based on SC and PPM technology are being built Entire magnet (~200m) pushes the limits for engineering design and construction of PPM and SC undulator magnets 'Workshop on Positron Sources for the International Linear Collider‘ : Daresbury Laboratory, th April’05 The workshop will discuss relevant issues for positron production for the ILC. Mag_Helical_ILC_Positron_Production_Workshop.htm

Thanks to Andrei, Mark Woodley, Mike Woods, Mauro, Marc Ross and Arnold for very useful discussions!