The JAI Linear Collider Program

1
The JAI Linear Collider Program

• The initial ILC research program of the John
  Adams Institute

2
Overview

• Introduction to the Adams Institute
• Advanced Beam Diagnostics
• Transverse beam profiles The Laser Wire Project
• Longitudinal beam profiles Smith Purcell
  Radiation
• Accelerator Simulations (BDSIM)
• Final Focus Stabilisation StaFF
• Acellerator Survey LiCAS
• Summary

3
The Vision

• To create a Centre of Excellence in the UK for
  advanced and novel accelerator technology,
  providing expertise, research, development and
  training in accelerator techniques, and promoting
  advanced accelerator applications in science and
  society.

Ken Peach
4
The Mission

• The John Admass Institute for Accelerator
  Science, based initially in the Physics
  Departments of Oxford University and Royal
  Holloway University of London, will work with
  other national and international accelerator
  laboratories and institutes, to promote and
  develop accelerator science in the UK. The main
  objectives of the Institute are
• to develop novel and advanced accelerator
  technologies for scientific applications,
  particularly but not exclusively for particle
  physics
• to make a major contribution to the design,
  development and construction of high energy, high
  intensity Linear Colliders
• to make a major contribution to the design,
  development and construction of high intensity
  proton sources needed for new high intensity
  neutrino sources, such as the Neutrino Factory
• to train a new generation of accelerator
  scientists and engineers
• to disseminate knowledge about the benefits of
  accelerator technology within the wider community.

Ken Peach
5
The people

6
The places
Oxford
RHUL
laboratories on Level 4 and Level 1 of DWB
7
The development(academic staff)

• Have hired
• director Ken Peach (new post)
• deputy director Grahame Blair
• Will hire
• 3 new lecturers JAI_at_Oxford/CCLRC
• 2 new lecturers JAI_at_RHUL/CCLRC
• 1 new departmental lecturer JAI_at_Oxford
• administrator secretary

8
The development(program and funding)

• Initial funding until 2007
• Universities for academic post and infra
  structure
• Existing research grants (LC-ABD, MICE, EuroTeV)
  2.3M
• After 2007
• PPARC support 0.4M pa
• continuation of University support for academic
  posts
• second round of existing project grants
• new projects

9
The development(new subject areas)

• Main parts of the program are ILC and NF
• New academics to start new research areas with
  synergies with ILC, NF
• future generic acceleration methods
• CLIC collaboration, jointly funded CERN fellows
  (stabilisation, alignment, pulsed RF)
• CLIC drive beam simulations
• CLIC Photo Injectors
• LHC
• beam diagnostics
• beam dynamics simulations for diagnostics (more
  knowledge from existing measurements)
• commissioning
• IFMIF (International Fusion Materials Irradiation
  Facility) D-Li neutron source, (synergies with NF
  proton drivers)

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Transverse beam profilingLaser Wire
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Laser Wire People

• BESSY
• T. Kamps
• DESY
• H. C. Lewin, S. Schreiber, K. Wittenburg, K.
  Balewski
• Oxford
• R. Bingham, S. Dixit, B. Foster, N. Delerue, D.
  Howell, A. Reichold
• Royal Holloway (UL)
• A. Agapov, G. Blair, G. Boorman, A. Bosco, J.
  Carter,
• L. Deacon, F. Poirier, M. Price, C. Driouichi
• University College London (UL)
• S. Boogert, S. Malton
• CCLRC Daresbury
• L. Jenner
• KEK
• A. Aryshev, H. Hayano, P. Karataev, K. Kubo, N.
  Terunuma, J. Urakawa
• Kyoto
• N. Sasao
• SLAC
• A. Brachmann, J. Frisch, M. Ross

JAI
http//www.hep.ph.rhul.ac.uk/lbbd/
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Beam delivery at the ILC

• ILC will accelerate electrons up to 250 GeV per
  beam (upgradable to 500 GeV)
• After acceleration, beams can not deliver
  required luminosity (31034cm-2s-1)
• Beam size must be reduced from 1 mm at end of
  linac to few nm at IP
• Need several correction optics to allow such
  strong focusing
• Corrections done in the beam delivery system
  (BDS) which is a few km long.
• Want to measure the emittance e in BDS.
• Need beam sizes at 4 different phases of b ? need
  section that is at least as long as b
• s ve vb sbeam size, bb-function
• achieve good resolution on s ? can live with
  small b
• At 1 TeV gey 0.04 mm-mrad
• Assuming resolution on s 3 mm (systematics
  limited) ? need b 441m (i.e. very long)
• No mechanical device can achieve this resolution
  nor stand the ILCs high currents a novel beam
  size monitor is needed.

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Laser-wire

• 532 nm
• (NdYAG)
• Power
• 1MW_at_PETRA
• 1GW_at_ATF

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Laserwire at PETRA2

• PETRA2 is a pre-accelerator for protons and
  electrons for the HERA collider
• Machine only available between HERA fills and
  HASYLAB synchrotron radiation runs

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Setup of Laserwire at PETRA2
100mm
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Setup of Laserwire at PETRA2
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Recent result February 2005 scan
Gaussian width Beam size ? Laser spot Gaussian
width 81.83 micrometers Laser spot 34.92
micrometers Beam size 74.01 micrometers
Plot by Steve Malton (UCL)
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ATF Laser Wire

• The ATF (Accelerator Test Facility) _at_ KEK built
  to demonstrate small emittance beams for ILC
• Ideal location for RD projects
• September install most laser-wire hard-ware
• Goal laser spot size 1-2 mm (comparable to the
  beam size)
• 1 mm only twice the laser wavelength ? very
  challenging!
• Requires a lens with a big aperture (f/1) and
  resistant to the high power delivered by the
  laser.

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ATF Laser Wire Location
20
ATF Vacuum Chamber Design
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Preliminary design study Lens option 1
The green cone shows the envelope for an aperture
of f/1
Lens mounting flange
The red cone shows the primary ghost from the
outer surface of the vacuum window
This sets the closest position for the lens and
hence its diameter
e - beam
Chamber
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Novel Indium seal

• keep forces on window low
• ensure ultra high vacuum seal

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2005 plans for ATF laser-wire

• March 2005
• study trip Study of the possible setup
  optics/infrastructure, first look at the laser,
  test of a possible photon detector.
• May/June 2005
• Learned how to use the laser, studied several
  possible beam optics in collaboration with Leo
  and Deepa from Daresbury, tested the Oxford
  vacuum seal, agreed on the location of the
  infrastructures and on the vacuum vessel design.
• September 2005
• Installation of the hardware at the ATF vacuum
  vessel, laser delivery path, final focusing lens
  DAQ
• November/December 2005
• First laser-wire run
• Our latest plans for our work at the ATF are
  posted at http//www-pnp.physics.ox.ac.uk/
  delerue/laserwire/atf.php

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Longitudinal Bunch profile diagnostics with
coherent Smith-Purcell radiation
Wade Allison , Victoria Blackmore, George Doucas,
Colin Perry and M.F. Kimmitt (JAI _at_
Oxford) (Dept. of Physics, Univ. of Essex)
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Basic principle

• N electrons (bunch) passing near periodic
  structure (grating) produce SP radiation,
  typically far-infrared.
• If bunch length ltlt wavelength
• ? coherent emission
• ? radiated energy depends on the longitudinal
  (time) bunch profile f(t) and square of
  electrons
• Measurements of radiation power over broad range
  of wavelengths can determine bunch profile f(t).
• Any EM phenomenon dependent on Q2 can be used but
  
• SP radiation is cheap to produce and
• disperses the signal according to ? (grating).

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Main features of SP-Radiation

• Radiation 250 800 mm
• Technique works well at low energies (5MeV) and
  14ps bunches, using liquid-He cooled detectors.
• ..but need to go to shorter bunches, higher
  energy, and, if possible, room-temperature
  detectors.
• Currently working at FELIX in Rheinhuizen, 50MeV
  1-3ps bunches, 0.5-1mm grating pitch
• Using array of 11 commercially available
  pyroelectric (PE) detectors.

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Detector array view of grating
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Objectives and status

• Pyroelectric detectors have worked very well.
• Fast electronics for PE detectors has also worked
  well.
• But.
• Significant background of unknown origin
  (diffraction radiation upstream??)
• So..
• Need carousel with 3 different gratings
  blank to investigate background.
• Need better lightcollection system ? Winston
  cone
• Need better filters (band-pass) to reject b/g ?
  strong overlap with astronomers and remote
  sensing groups.

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Next steps (2005-2006)

• Pending a more accurate determination of
  magnitude of background component, no definitive
  statement on bunch profile, but...
• First indications are that the bunch is
  non-Gaussian, with about 90 of particles inside
  1.5ps.
• This is a tentative conclusion, to be confirmed
  through the use of new filters and new optical
  system.
• Continue runs at FELIX but, at the same time,
  plan for tests in the GeV regime.
• Continue with theoretical work on radiative
  processes, signal amplitude and data analysis
  (reconstruction determining, then inverting the
  Fourier Transform of bunch shape)

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BDSIM
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Overview

• Code for particle-matter interactions in
  accelerators
• Designed for background studies in linear
  colliders
• Geant4 accelerator description
• Beamline constructor
• All native Geant physics processes
• Fast tracking procedure
• Own physics processes
• Synchrotron radiation etc.
• .....
• Interfacing to other geometry formats

ATF extraction line
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Status

• Fast processes for large-scale simulations
• Matrix formalism for simple multipole magnets
• improved tracking synchr. rad., bremsstrahlung,
  muons
• Geometry description
• Uses MAD extension for beamline definition
• Mokka description where necessary (i.e. IR)
• Output Root, ASCII
• Beta release Jan 2005, v1.0 release this summer
  on http//cvs.pp.rhul.ac.uk

33
Current simulation projects

• ILC IR and extraction line backgrounds
• ILC collimation system
• ILC laserwire backgrounds
• ATF laserwire backgrounds

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IR geometry Set-up
35
Pair Backgrounds
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Ongoing work

• Hadronic
• interfacing to MCNP cross-section database
• development of fast neutron Monte-Carlo transport
  
• EM
• Shower simulation optimization (LPB etc.)
• Cuts distribution scheme
• Beam-gas interaction
• Interfacing to more detector and accelerator
  description formats
• Benchmarking with MARS and STRUCT

37
StaFF(Stabilisation of the Final Focus)the
youngest JAI project
David Urner Paul Coe Armin Reichold JAI_at_Oxford
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StaFF Motion Stabilization with Nano-Meter
Precision

• Develop laser interferometric methods to monitor
  relative position of two objects at
• Nanometer scale resolution.
• For separations of order 10m.
• Frequency range 100Hz 0.01 Hz
• Development of active feedback systems to monitor
  and stabilize
• final focus quadrupoles
• BPMs in the energy spectrometer.
• StaFF at KEK Stabilize Nano-BPM systems relative
  to each other.

1nm
KEK Integrated spectrum of vertical motion
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StaFF at ATF
40
StaFF at ATF

• Accuracy O(10 nm) vertical displacement between
  KEK and SLAC BPMs.
• Project 6-D coordinates from one BPM via middle
  triangle to the other BPM.

KEK BPM
SLAC BPM
Floor node

• Red lines Michelson interferometer displacement
  meter nm resolution.
• Multilateration requires absolute distance meter
  with mm resolution FSI.
• Both systems with same setup!

41
StaFF at ATF Opto-Geometrical Simulation
Simulgeo

• Resolution of distancemeter 1nm
• Mount stability of distancemeter 1nm
• Angle stability of distancemeter holder 10 mrad.
• SLAC BPM reference

• KEK BPM variable (6D)
• Position x32 y19 z2 nm
• Angle x0.01 y0.01 z0.1 mrad

Note 1mm absolute distance resolution needed
to determine constants required to solve
geometry ? FSI
42
Plans for StaFF at ATF

• RD at Oxford
• Michelson Interferometer prototype in Lab.
• FSI with same setup.
• Build frequency stabilized laser.
• Test zero force mounting mechanics prototype.
• Design vacuum system.
• Build triangle and BPM nodes ready for KEK.
• Write algorithm and software for active
  stabilization.
• Closing of feedback loop.
• RD at KEK
• Run single arm prototype in accelerator
  environment.
• Measure angular deflection of I beam.
• Mount floor and BPM nodes.
• Survey mounted nodes.
• Mount vacuum tubes.
• Install interferometer.
• Setup and first test of system.

Nov 05 Nov 05 Jun 06 Aug 05 Sep 05 Dec 05 Aug
06 Dec 06 Jan 06 Apr 06
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LiCAS

• Linear Collider Alignement and Survey

44
LC Survey Problem

• Survey multi step process with single tolerance
  budget driven by accelerator physics
• component construction
• component fiducialisation
• component Survey ? LiCAS
• machine Alignment ? LiCAS
• Components Survey
• 200mm vertical our slice of tolerance budget
• over 600m O(betatron) wavelenght
• Open air survey too inaccurate and too slow
• New instrument ? RTRS (Rapid Tunnel Reference
  Surveyor)
• RTRS uses LiCAS survey technology

45
LC Survey Problem

• Complex irregular layout and machine
• Horizontally and vertically curved sections,
  (Rmingt500m)
• Some sections geometrically straight, others
  following geoid
• Sections with significant slopes

• Many different section (Linac, BDS, DR, )
• Possibly many beam lines

• Temp. pressure gradients in tunnel
• Very tight space (1m wide)
• Space serves as emergency escape route
• ? Classical Survey too inaccurate slow
• No long-term (gtmonths) stable reference monuments
  at O(10 mm) level
• ? Need frequent surveys
• ? Need automated process
• ? Need regular reference structure
• ? Use regular markers in tunnel wall
• ? transfer coordinates to machine over short
  distance across tunnel (stake out)

46
LC Survey Problem
Fiducial marker
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Who works on LiCAS (Oxford team)
studentic
Cecilia Uribe start 1.9.05
academic
David Urner
Elec. Tech.
electronic
Ashley James
John Dale start 1.10.05
Mech. Tech.
optic
mechanic
48
Oxford Alumni
Collaborators
David Howell

• Johannes Prenting
• Markus Schloesser
• Ernst-Otto Saemann
• Daniel Kaempnter

Edward Botcherby
Robert Apsimon Peter Baker Ken Chuang
Brtek Szczygiel student
Thomas Zlosnik Simon Wilshin Chris Glassman
Gregorz Grzelak
49
RTRS concept
Tunnel Wall
LiCAS technology for automated stake-out process
Reconstructed tunnel shapes (relative
co-ordinates)
50
LiCAS Measurement Principle
Internal FSI System Dz. Dx,Dy Da,Db between
cars
Extrenal FSI System measures Wall marker location
Straightness Monitor Dx,Dy Da,Db between cars
51
Camera Module
Wall mounted retro-reflector
Internal FSI beams and LSM beam
External FSI beams
All measurements in mm
52
Inner Chassis

• Inner Chassis provides
• 6-DOF motion for unit alignment
• vibration damping
• sensing of tunnel bar codes

53
RTRS global Mechanics

• Measurement car
• full 3D designs workshop drawings
• production schedule finalised
• Service car
• full design
• commerical propulsion system under test in Oxford
• gathering information for final services routing
  and power requirements
• incorporating safety systems

measurement car
service car
54
Tunnel _at_ DESY

• 60m long service tunnel at DESY
• fully airconditioned
• tunnel tests confirm wall stability
• installing high speed WLAN
• installing more interlocks and safety measures
• ready for use well before RTRS prototype

55
Performance Simulations

• Simulgeo opto-geometric model with error
  propagation over O(15) train stops (memory
  limited, extremely compute intensive)
• Multi dimensional random walk model fitted to
  first 15 stops

• 600 m sections with random walk models (fast)
• Fit best straight line to 600 meters
• look at residuals
• well below spec.
• 200 mm vertical (Y)
• 500 mm horizontal (X)
• residuals input to beam based alignment
  simulations (Snowmass)

56
FSI News
Splitter Tree

• Short 6-line FSI system for 3D wall marker
  measurement works without collimation optics

Amplifier
Laser
Retro Reflector
3D-Piezo Stage
57
Naked fibre launch for external FSI
required coverage area 50 x 50 x 50 mm3 distance
to wall 420mm largest off axis distance that can
occur 32mm

• Original approach
• use large Ø collimated beam
• requires large optics ØO(100mm)
• very costly O(10k per line)
• high return fraction gt 10-3
• good signal to noise ? easy detector and
  amplifier
• New approach
• use naked angle polished fiber with diverging
  beam
• suffer return loss up to 10-9 ?1mW in ? 1pW back
• develop extremely low noise and low bandwidth
  (lt20 kHz) amplifier
• high sensitivity detector

58
Normalised power spectra from naked fibre 35 mm
off axis
signal
no signal
59
More news about FSI

• Completed Masters Projects
• calibration of external FSI system
• displace retro reflector with high precision 3D
  motion stage while measuring position with FSI
  lines O(20 position)
• obtain origins of FSI lines via consistency
  fitting
• very good numerical algorithms for geometrical
  reconstruction
• can also obtain some parameters of stage metric
• multiple distance measurements with single FSI
  line
• studied minimal resolvable length differences
  down to 100mm
• simulated up to 5 distances in one line

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LSM

• Used to measure car transverse translations and
  rotations
• Require 1mm precision over length of train

Rotation Spots move opposite directions
Translation Spots move same direction
CCD Camera
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62
LSM camera comparison
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LSM camera noise comparison
Dolphin Noise decreases with rel. intensity
Sony Noise increases with relat. intensity
64
LSM camera comparison

• The winner is
• Sony XCE 150 CE
• the cleanest camera

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LSM fitting and beam finding (Sony)
Narrow (s1.5mm) beam fitting
Wide (s2.5mm) beam finding
Errors in microns for Clean camera, 10-bit
Errors in microns for Clean 8-bit camera
100mm
10mm
realistic dusty camera
Clean 10-bit camera
X-coord
Y-coord
X-coord
Y-coord
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Future Plans

• Up to autumn 2005
• Completion of FSI and LSM and global analysis
  codes
• Production of Electronics
• Construction of 3-car prototype components
• Partial assembly of inner systems at Oxford
• Sub-system calibrations
• Installation in DESY test tunnel 1. Nov. 05

67
Future Plans

• Up to Spring 2006
• Operate prototype at DESY
• commissioning
• many calibration programs on full train
• multiple test surveys of tunnel
• tuning of operation and analysis algorithms
• study of systematic errors
• Up to Spring 2007
• In Oxford
• Improvements of component calibration programs
  hardware
• Design of second generation instrument for X-FEL
• much smaller ? fits into real accelerator tunnel
• much simpler ? reduce from RD to production
  functionality
• 6 cars
• Design stake out instrument

68
Future Plans

• Up to Spring 2008
• Operate improved first prototype at DESY
• Construct second prototype
• Operate second prototype
• Construct stake out instrument
• Operate stake out instrument

(needs additional funding)
69
Summary

• JAI is conceptually new in the UK
• Hosted by RHUL and Oxford Physics
• Expanding range of accelerator projects
• Emphasis on ILC and NF
• Builds on strength of LC-ABD and Mice
• ILC project tenors Lasers for accelerators and
  advanced beam diagnostics
• Laser Wire
• Staff
• LiCAS
• Smith Purcell Radiation
• Simulation project BDSIM