ILC Instrumentation Development

June 15, 2005 Marc Ross (ILC) – Instrumentation Development

ILC Instrumentation Development

Marc Ross, SLAC


Overview: 1) Build on experience at SLC/PEP II by:

Developing instrumentation and related controls with capability directed squarely toward the needs of ILC and other next generation accelerators TRC R2/3(focus on precision position & profile measurements – long. & transverse)

Seeking out and binding worldwide expertise on critical beam monitoring and control issues

(application beyond ILC)

2) Promote the use of ATF, TTF and ESA for this purpose

ATF (DR, low emittance extracted beam) & TTF (SCRF, short bunch) & ESA (short bunch high E) are unique ILC test facilities

3) Bring - to students - the opportunity to work on hardware in a developmental environment

Manageable projects beyond the reach of operational pressures



International Collaboration 2001-2005

• DESY/SLAC Projects at TTF (TESLA Test Facility)– Gun breakdown location using ultrasound location– Precision bunch length monitor σ_z ~ 5 microns “LOLA” (FEL-

2005)– SCRF Cavity Higher Order Mode BPM – 3 um resolution (PAC-

05)• KEK/SLAC/LBL Projects at ATF (Accelerator Test

Facility – KEK)– Beam Based Alignment Phys. Rev. Lett. 92, 054802 (2004)

Achievement of Ultralow Emittance Beam in the Accelerator Test Facility Damping Ring

– Coupled bunch instability studies – based on precision CW laser-based profile monitor

• Many instrumentation projects ...


Recent developments at ATF• ‘Precision’ instrumentation projects addressing

BD / DR issues– Technical coordination / leadership by SLAC

• (also logistics)

• Truly global support / global interaction– KEK / Japanese Universities – UK (LCABD)– EU (EuroTeV)– SLAC– LLNL– Cornell

US/UK/KEK ATF team (March 8 2005)

• By institutional nationality : – 12 Japan, 12 UK, 4 US

(~ part of the group … 25 non-Japanese users in May 2005)

ATF Instrumentation Projects: 1. RF Cavity Beam Position Monitors

– Fundamental RD aimed at RF-BPMs throughout the ILC• Linac (large bore, low loss factor, high resolution)• BD (large bore, high resolution)• Energy spectrometer

– No one has experience with large RF cavity BPM systems• BPM is the most critical beam instrument (SLC, TeV,

PEPII…)– Typical requirements ~ 100 nm @ 1 inch diameter

• ATF achieved: 15 nm for ½ inch diameter (short term)• Long term stability (offset and gain) studies underway

– 60 nm over 2 hours achieved• Thermal limit is 5 nm

– Projects in process: Beam tests of 6 BPMs & development of electronics for ATF2

ATF Instrumentation Projects (2):2. Laser-based beam profile monitors

• Mechanical ‘wire’ scanners will not work in ILC• Build on experience at ATF (ring), SLC and FFTB• Royal Holloway/Oxford lead; SLAC technical partner

– 1 ~ 2 micron scanner by 12/2005 • 1% resolution; fast scanning

3. Stabilization systems – beam feedback and other– Fast (low latency) feedback (Queen Mary)

• SLAC is a technical partner• Tested 2005

– Optical ‘struts’ (extension of ATLAS system) developed at Oxford• 10 nm stabilization over 10 m baseline with ~ hour

timescale using 25 Michaelson /frequency scanning interferometers

TTF Instrumentation Projects (1)

•Kicker used to select single bunch out of 1MHz bunch train•Deflecting cavity pulse 1 microsecond only streaks selected bunch•In principal, resolution is (unstreaked spot size / maximum streak rate)

Transverse deflecting structure to measure longitudinal profile

May 23, 2005 Marc Ross – TTF Program

Unstreaked, vs. Streaked Spots

Power = 4.8MW, corresponding to 4.5fs/pixel

1 picosecond


Beam without and with BC 3 (second bunch compressor)

Scans at high power ~16MW

1 picosecond 1 picosecond

13 femtosecond FWHM spike!


TTF Instrumentation Projects (2)

• Use of SCRF cavity dipole higher order mode signals as beam position monitors

– Cryomodule assembly alignment check– Beam steering and tuning at TTF

• HOM readout tested October 2004 & April 2005– Proposal for 80 channel heterodyne receiver/digitizer

system submitted. Discussed with DESY.• Prototype development underway. Full approval needed July

for November delivery.• M/S largely funded by DESY/Saclay.

– Four micron resolution demonstrated (single bunch). (PAC 05).


Instrumentation Project Summary

Instrumentation / Kicker Projects M/S cost (US FY06/JFY05)

total (inc. labor) Key date

ATF Cavity BPM RD 60 90 2006ATF 2 Cavity BPM electronics production 131 238 4.2006Fast Kicker RD (tests at ATF) 100 1400 2007ATF Ring BPM upgrade (for ATF2) 80 736 4.2008ATF Technical partnerships 30 281 2007TTF HOM BPM electronics 181 311 11.2005TTF LOLA 15 30 2006


Extra


• Coherent Synchrotron Radiation (DR) incoming Sokendai graduate student/KEK

• Ring BPM upgrade: reduce resolution from 3~4 to 0.2 um (funded through US/Japan)

• ATF-2 cavity BPM electronics (US/Japan)

May 23, 2005 Marc Ross - PEP II Projects

PEP II

• Program: Provide help as requested by SLAC Director (~late 03)

• (not on the agenda, but an important goal for 2004 extended into this year)

• Two major systems installed:• LER X-ray Synchrotron Radiation monitor

– Goal: measure beam size accurately in LER up to full intensity without ‘tilt’ distortion present in existing monitors

– Smallest measurable beam size ~ 10 um, well below smallest expected LER sigma_y

– Bunch – by – bunch beam size for EC measurements• X-ray technology extremely important for ILC DR

monitors

May 23, 2005 Marc Ross - PEP II Projects

PEP II (2)

• Beam Based Alignment– LER BPM offsets / misalignments in IR2 region are extreme;

arcs important but…– Installed 32 shunts from SPEAR; BBA possible on 61 magnets– Installation completed 16.03.2005– Quad string operation started 24.03.2005

• Shunts tested ok

• Goal 2005: BBA understanding of LER BPM systematics & IR misalignments to <100 um– HER BBA resulted in significant Luminosity improvement

through dispersion correction

• Ring BBA is extremely important for ILC DR / ATF

Documents

ILC Instrumentation Development