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IP Beam Instrumentation Summary
ALCPG Linear Collider Workshop January 10th, 2004 SLAC

Eric Torrence University of Oregon

· Current Status · Technology Issues · Testbeams

Eric Torrence

1/12

January 2004


Working Group Challenge

Ensure adequate beam instrumentation to meet physics needs of LC

Machine

Detector

Physics

Prime topics · Luminosity · Beam Energy · Polarization We try to take a broad view... International effort Problems trancend regional and thermal differences
Eric Torrence 2/12 January 2004


BI Design

Move from conceptual to more concrete designs

Polarimetry · Pretty good shape

Luminosity (Spectrum) · Sketch of hardware is there, need to flesh out details · Understanding Lumi spectrum not in hand Need to engage physics groups!

Beam Energy · Need `real-estate' planning · Understand role of beam-based vs. physics

Eric Torrence

3/12

January 2004


Forward Detectors
0.5

0.4

113mrad

0.3

0.2

Inst. Mask W 46mrad Pair- LuMon

W

0.1

0

QD0 BeamPipe W LowZ Mask Exit radius 2cm @ 3.5m W Support Tube HCAL
2 2.5 3

-0.1

-0.2

-0.3

-0.4

-0.5 0 0.5 1 1.5

E C A L

YOKE
3.5 4

Specify geometry detail for both Gas Cherenkov and 3D Silicon detectors in this region

Must be fast (1 ns) to avoid pair pileup in far-forward region (warm) T. Maruyama
Eric Torrence 4/12 January 2004


Technology Decision

Warm vs. Cold?
Eric Torrence 5/12 January 2004


Crossing Angle

· Big push in Europe to study this for Paris · Many issues: IP layout, backgrounds, physics acceptance, extraction-line design, risk · being well covered by Beam Delivery & NLC · Also BI issue of downstream instrumentation Nice talk from G. Wilson on physics and hermeticity in the forward detectors

Biggest question: is this really an issue at all?

Meeting at Zeuthen January 19th Please attend (at least virtually) if you have input

Eric Torrence

6/12

January 2004


Bunch Structure

1.4ns sounds hard 337ns sounds easier
Need a much more quantitative statement

Understand needs for fast diagnostics Example: To what precision do we need Ebeam pulse-to-pulse? With what freqency?

Assess impact or risk on physics!

Eric Torrence

7/12

January 2004


Luminosity Spectrum

5000 4000 3000 2000 1000 0 486

Guinea Pig Simulation With `realistic' beams NLC500

488

490

492

494

496

498

500

502

504 ECM

Ugly profile for warm, broader width Need real numbers on physics from real analyses

Eric Torrence

8/12

January 2004


End Station A Testbeams

Beam Instrumentation Tests for the Linear Collider using the SLAC A-Line and End Station A M. Woods, et. al. SLAC-LOI-2003.2 27 Physicists, 10 Institutions
http://www.slac.stanford.edu/grp/rd/epac/LOI/LOI-2003.2.pdf

Letter of Intent submitted Nov. 2003 Well received by SLAC EPAC and lab

Testbeam for Beam Instrumentation Detectors Exploit infrastructure/knowledge from E158

Test some of the high risk BI components Start a facility for beam instrumentation R&D
Eric Torrence 9/12 January 2004


X-band Comparison

E158

NLC

Charge/pulse Rate Energy Pulse Train uBunch spacing Beam Loading Energy Spread Intensity Jitter Energy Jitter Transverse Jitter

6 в10 120 Hz 45 GeV 270 ns 0.35 ns 13% 0.15% 0.5% 0.03% 5% of spot

11

14 в10 120 Hz 250 GeV 267 ns 1.4 ns 22% 0.16% 0.5% 0.3% 20-50%

11

For X-band, current beam very comparable (except energy and spot-size) Thin radiator can replicate disrupted beam Good infrastructure currently exists, but no physics planned for ESA!

Eric Torrence

10/12

January 2004


Disrupted Beam

NLC 500 ESA 25 w/ target

M. Woods, L. Keller

10% X0 carbon target

LE Pairs

Eric Torrence

11/12

January 2004


Testbeam Proposals · User-driven proposals · Need technical descriptions · Combine requests into blocks, run plan Proposal to SLAC EPAC by May 2004 First Phase · IP BPMs - fast feedbacks · Energy BPMs · Synchrotron-stripe diagnostics (WISRD) Starting with ~1 week in 2005 Later Phase(s) · · · · · Pair-monitor tests Beam diagnostics, "wire" scanners Spectrometer prototype Polarimeter prototype Your good idea!

Expect 1-2 weeks per year Please contact M. Woods or E. Torrence Greater participation is welcome
Eric Torrence 12/12 January 2004