NLC - The Next Linear Collider Project

Machine-Detector Interface

Tom MarkiewiczLC R&D Opportunities, SLAC

May 21, 2002

Tom Markiewicz

NLC - The Next Linear Collider Project

Machine Detector Interface500 GeV TRC Optics w/ Large Detector

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0 2 4 6 8 10 12 14

Tom Markiewicz

NLC - The Next Linear Collider Project

-20m < Issues < 200m

• Backgrounds• Simulations• Final Doublet Magnet Technology• Vibration Stabilization• IR Layout• Instrumentation (L,E,& P + other)• Vibration Sources: measurement &

modeling IR Issues

Tom Markiewicz

NLC - The Next Linear Collider Project

Backgrounds

IP Backgrounds:•Beam-Beam Interaction

•Disrupted primary beam•Extraction Line Losses

•Beamstrahlung photons•e+,e- pairs from beams. interactions•Hadrons from beams. interactions

•Radiative Bhabhas

Machine Backgrounds:•Synchrotron Radiation•Muons Production at collimators•Direct Beam Loss

•Beam-Gas•Collimator edge scattering

•Neutron back-shine from Dump

Experts:Takashi Maruyama/SLAC

Lew Keller/SLACJeff Gronberg/LLNL

Stan Hertzbach/U.Mass

Programs:Guinea Pig / CAIN

GEANT 3 / GEANT 4EGS / FLUKA

TRANSPORT / DIMAD / TURTLEMUCARLO

QSRAD

Tom Markiewicz

NLC - The Next Linear Collider Project

Background Simulation Results

Tom Markiewicz

NLC - The Next Linear Collider Project

Background Projects

• Iterate all results for consistent set of results– Beam parameters, detectors, solenoid design,

beamlines not consistent• Detector response to known backgrounds

– TPC, Cal, Lum, Pol, etc.• Dose calculations on SC or REC QD0• Collimator scattering study:

– Locations, apertures, beam loss, …• GEANT4 beamline model -Hadron production• …• …

Tom Markiewicz

NLC - The Next Linear Collider Project

Simulations

Experts:Peter Tenenbaum/SLAC

Andrei Seryi/SLAC

Tom Markiewicz

NLC - The Next Linear Collider Project

Simulation Projects

At SLC/SLD LUMINOSITY and BACKGROUNDS dominated EXPERIMENTAL daily concern

I am sure last factor of 10-100 will be a struggle at the next LC

There are an infinite number of Monte Carlo-like studies that can be made to understand luminosity loss mechanisms and ways to ameliorate them.

• Repeat background studies for ”real” machine with non-ideal alignment, magnet settings, ground motion, …

• Tolerance parameter study

Tom Markiewicz

NLC - The Next Linear Collider Project

Final Doublet Magnet Technology

Magnet Aperture Gradient Rmax Z_ip LengthQD0 1.0 cm 144 T/m 5.6cm 3.81 m 2.0mQF1 1.0 cm 36.4

T/m2.2cm 7.76 m 4.0 m

Experts:Andy Ringwall/SLAC-PEP3

Brett Parker/BNL

Tom Markiewicz

NLC - The Next Linear Collider Project

Magnet R&D Topics

• Permanent– Radiation hardness– Temperature sensitivity– Tuning schemes– Effect of solenoid fringe field: BZ, BR, FZ– Incorporate beam pipe & vacuum system

• Superconducting– Temperature load from e+e- pairs, SR, leads,

support– Field stability: appropriate sensor

• Flowing Helium• External connections

– Mechanical rigidity against vibration– Vibration sensors / actuators appropriate inside /

outside cryostat

Tom Markiewicz

NLC - The Next Linear Collider Project

Inertial Vibration Stabilization Projects

• Sensor design• Algorithms• Simple 3m pseudo-magnet test• Relative motion of two blocks

Experts:Joe Frisch/SLAC

Linda Hendrikson/SLACTom Himel/SLACEric Doyle/SLAC

Leif Ericksson/SLAC

Tom Markiewicz

NLC - The Next Linear Collider Project

Interferometric Vibration Stabilization

Experts:Tom Mattison/UBCMike Woods/SLAC

Tom Markiewicz

NLC - The Next Linear Collider Project

IP Girder Test Concept

STS2 STS2 STS2STS2 STS2

Witness IF

O.A. IF

7m

7m

.5m

4.5m

–Support tube (Carbon fiber?)–Permanent magnet or model–Interaction with external solenoid field–Hard or soft actuators–Beam pipe & vacuum

Tom Markiewicz

NLC - The Next Linear Collider Project

IP Feedback Projects

Experts:Phil Burrows/OxfordGavin Nesom/OxfordSimon Jolly/Oxford

Glenn White/OxfordColin Perry/Oxford

Joe Frisch/SLACSteve Smith/SLAC

Amp

BPMProcessor

IP Round Trip Delay

+

Amp

•NLCTA Improvements:•Better beam conditions•Better hardware, DAQ, …•Solid State Kicker

•Other sites: •ATF (KEK)•PePII

Tom Markiewicz

NLC - The Next Linear Collider Project

IR Design

Experts:Tom Markiewicz/SLACKnut Skarpaas/SLAC

Tom Markiewicz

NLC - The Next Linear Collider Project

Realistic IR Layout

500 GeV TRC Optics w/ Large Detector

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0 2 4 6 8 10 12 14

Masking SupportVXD support & alignmentInstrumented MasksLum_Pair MonVacuum req.

•REC QD0•SC QD0

•Beampipe supportAperturesOptical lines of sightDetector access

Tom Markiewicz

NLC - The Next Linear Collider Project

Instrumentation

• Lum, Energy & Pol Instrumentation (to be) addressed by MikeWoods & Eric Torrence

• Other:– Halo Monitor: Need a good idea

• SLD/SLC: Ran a wire or collimator edge into the beam and looked at CDC & Calorimeter response

Tom Markiewicz

NLC - The Next Linear Collider Project

Vibration Sources: Measurement & Modeling

1E-4 1E-3 0.01 0.1 1 10 100

0.1

1

10

100

"Model A"

"Model C"

"Model B"

Inte

grat

ed rm

s m

otio

n, n

m

Frequency, Hz

Example of integrated spectra of absolute (solid lines) and relative motion for 50m separation obtained from the models

Importance of this topic to stable luminosity makes it important part of the EXPERIMENTAL program and DETECTOR design• Participate in current

measurements• Sites• Equipment Noise

• Design of IR that mitigates and minimizes man-made sources

• ANSYS sims of detector• Industrial vib. suppression

tools applied to HEP

Experts:Andrei Seryi/SLAC

Fred Asiri/SLAC

Tom Markiewicz

NLC - The Next Linear Collider Project

IR Issues

Experts:Jeff Gronberg/LLNLDavid Asner/LLNLKen Skulina/LLNL

Jim Early/LLNL

Tom Markiewicz

NLC - The Next Linear Collider Project

IR Projects

• Mercury Laser Project– Fusion R&D, comes for free

• IR Optics– ½ NLC Scale, suitable for LINX/SPHINX is being

built• Test laser beam diagnostics and control with low

power laser– Beam Tests:

• Laser=?• Beam=SLC ?• Engineering Tests:

– Collision stability– Luminosity as function of particle/spin combination– Two photon hadronic backgrounds

• Physics Measurements