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

EUROTEV3 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

BDSLD CRABRF FFBK SWMD SCFD

Tasks cover critical design choices for the BDS

BDSLatticeDesign

Crab cavityRF systemDesign

FastFeedbackSystemDesign

SpoilerWakefields& MechanicalDesign

Super-conductingFinal Doublet R&DCCLRC

CEACERN

CCLRCULANC QMUL

CCLRC

CCLRCCERNTEMFUMANULANC

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

NLC TESLA

Frank Jackson

NLC and TESLA halos at final doublet (Uniform phase space, 1% energy spread, MERLIN 2nd order transport)

Extraction Line

l*=4.1m

1.3-2.3m

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:

Required B Field to Produce 20 MeV Photons

0

1

2

3

4

5

6

7

0.4 0.9 1.4 1.9 2.4 2.9

Undulator Period (cm)

On

Axi

s B

Fie

ld (

T)

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 , 11-13th April’05

The workshop will discuss relevant issues for positron production for the ILC.

http://www.astec.ac.uk/id_mag/ID-Mag_Helical_ILC_Positron_Production_Workshop.htm

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