NLC - The Next Linear Collider Project

IR Working Group Summary

Tom MarkiewiczLC R&D Workshop, UCSC

June 29, 2002

Tom Markiewicz

NLC - The Next Linear Collider Project

IR Group People

NLC Accelerator Physics GroupNLC Beam Delivery & IR Group

LLNL GroupUniversity Groups

– Oxford University– U. of British Columbia

– Northwestern University– U. of Massachusetts

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 Measurements for Physics in Beamline Inst. WG

• Vibration Sources: measurement & modeling

IR Issues

Tom Markiewicz

NLC - The Next Linear Collider Project

One Parallel Session

• Background Update– Takashi Maruyama / SLAC

• IR Layout & R&D Status– TWM / SLAC

• SLC Testbed– Jeff Gronberg / LLNL

• Polarization Measurements at SLC Testbed– Sahal Yacoob / NorthWestern University

Tom Markiewicz

NLC - The Next Linear Collider Project

Background Simulation Results

Tom Markiewicz

NLC - The Next Linear Collider Project

User Files Available

• Direct hits on VXD from 1900 bunches:– /afs/slac/www/accel/nlc/local/systems/

beamdelivery/guinea_pig/ver_1999_07_08/nlc500h/pairs/

» LD_direct» SD_direct

• Need discussion with relevant groups to determine best way to transfer results on secondary charged particles, photons & neutrons– Results of GEANT or FLUKA runs– Normalized, parameterized energy & spatial or

angular distributions?

Tom Markiewicz

NLC - The Next Linear Collider Project

Beamline: Collimators & Synchrotron Radiation

IP

Spoilers & Absorbers

R=1cm

SR Photons at IP

Collimation Depth:Was: 8x x 40y

Now: 19x x 52y

400m 850m

107 Halo left after E_Slit

E_Slit

10

100

Oct Off

Oct On

Tom Markiewicz

NLC - The Next Linear Collider Project

Inertial Vibration Stabilization Projects

• New Sensor – under construction

• Simple 3m pseudo-magnet test– Parameters & parts defined

• Relative motion of two blocks– Wait for new sensor & retest of single block

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

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0 2 4 6 8 10 12

LCD-L2 (3T) with 3.8m L* OpticsSnowmass 2001

QD0SD0

M1

Calorimeter

Pair LumMon

M2

Beampipe

Low Z shield

32 mrad M1 acceptance

Support Tube

6.3 mrad Lum-Mon acceptance

1 mrad exit aperture

QF1 SF1

52 mrad Cal acceptance

Feedback BPM & Kicker

Tom Markiewicz

NLC - The Next Linear Collider Project

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

0 2 4 6 8 10 12 14

Current IR Thinking

M1

M236 mrad M1 acceptance

117 mrad Cal acceptance

25 cm radius support tube

Tom Markiewicz

NLC - The Next Linear Collider Project

Final Doublet Magnet Technology

Magnet Aperture Gradient Rmax Z_ip Length

QD0 1.0 cm 144 T/m 5.6cm 3.81 m 2.0m

QF1 1.0 cm 36.4 T/m

2.2cm 7.76 m 4.0 m

Tom Markiewicz

NLC - The Next Linear Collider Project

Photon Collider Testbed HardwareOptical Assembly

• Unknown factor: Optics damage– IP cannot often be opened up to fix the optics

• Radiation damage to the coating• Laser power damage to the mirrors

– What is the MTBF?

½ scale version of the NLC designPosition of final quads in SLC sets the scale

Final focus optics are fixedSteering mirrors are on piezo movers

Tom Markiewicz

NLC - The Next Linear Collider Project

Engineering Test Facility at SLC

Beam EnergyDRx,y (m-rad)

FFx,y (m-rad)

x / y

z

x,y

N

30 GeV

1100 / 50

8 / 0.1 mm

0.1 – 1.0 mm

1500/55nm

6.0E9

Tom Markiewicz

NLC - The Next Linear Collider Project

Photon Collider Testbed Hardware ½ Scale prototype of optics / alignment system is

currently under construction

Beampipe

Alignment System

Tom Markiewicz

NLC - The Next Linear Collider Project

Concluding Statement

• There are many tools & resources that have been developed already by NLC sponsored “Machine Detector Interface” group

• Transfer of tools & projects to fresh faces would help project and provide a relatively easy way into the accelerator R&D world for interested groups or individuals