proton delivery to target keith gollwitzer accelerator division fermilab map 2012 winter meeting...

Proton Delivery to Target

Keith Gollwitzer

Accelerator Division

Fermilab

MAP 2012 Winter Meeting March 7, 2012

Gollwitzer -- Proton Delivery to Target 2

Outline• Conceptual delivery of beam to target• Effects of target solenoids on proton

beam(s)– Cross check with some work on target

optimization– Further investigations

• Parallel work done by Eliana Gianfelice-Wendt and myself– Tracking, Matrices, Spreadsheets....

March 7, 2012


Neutrino Factory Delivery Concept

• Task Force concept is to operate the pulsed linac at 15 Hz.

• Accumulate 9 or 12 bunches• Transfer 3 bunches to Compressor• Rotate and then extract bunches with

correct bunch spacing of 120 μs

– Effectively 45 or 60 Hz

March 7, 2012


Muon Collider Delivery Concept

• Task Force concept is to operate the pulsed linac at 15 Hz.

• Accumulate 4 to 8 bunches• Transfer all bunches to Compressor• Rotate and then extract bunches in single

turn• Each bunch is sent on a different path

(trombone) so that they all arrive at the target instantaneously

March 7, 2012

5Gollwitzer -- Proton Delivery to Target

Muon Collider Trombone

March 7, 2012


Single Beam to Target

• Want to know how solenoid will affect proton beam line

• Start from work done on optimizing target– Ding, Berg, Cline and Kirk, “Optimization of a

mercury jet target for a neutrino factory or a muon collider”, PRST-AB 14. 111002 (2011)

– Uses 2011 target station concept and varies many parameters to optimize the number of usable muons (uses 8 GeV proton beam)

March 7, 2012


PRST-AB Optimization

March 7, 2012

Jet/Solenoid angle: 96.7 mradJet/Proton Beam angle: 27 mrad at IPJet radius: 0.4cmProton Beam Energy: 8 GeV

Proton Beam is GaussianProton Beam Radius (rms) is 30% of jet radiusSolenoid Field is 20 T in interaction regionJet is in y-z plane


PRST-AB Optimization

• Initial optimization is with beam coming from below– Roll angle of 180o

• Investigate proton beam azimuthal approach– Propagate proton beam back to -75 cm– Helical paths for beam to always intersect at

(0 cm, 0 cm, -37.5 cm)– Investigated 15 paths with different roll angles

into the jet

March 7, 2012


Need Solenoid Information

March 7, 2012

“The Target System Baseline”, Kirk & McDonald (Feb 4, 2011)

Proton Beam in Solenoid

field


Solenoids Layout

March 7, 2012

z (cm)

r (cm)


Field on axis

March 7, 2012

z (cm)

B_z (T)


Radial field

March 7, 2012 z (cm)

B_r (

T)

r = 7 cm

From Ding


Reproducing PRST-AB Beam Paths -75 cm to -37.5cm

March 7, 2012


Beam Distance from Jet

March 7, 2012

Clea

ranc

e is

in b

eam

sig

mas

at -

75 c

m


X & Y vs Z

March 7, 2012


X vs Y

March 7, 2012

8m to IP

0.5m to IP


Single Beam Path• Optimization of

muons per roll angle results in roll of 264o

• Roll of 95.4o results in hitting jet twiceZ = -123 and -37.5 cm

March 7, 2012


Beam Size

Z [m] σrms [cm]

-3 1.06

-4 1.45

-5 1.85

-6 2.25

-7 2.65

-8 3.05

• At IP, σrms = 0.12 cm

• Optimization shows that β* ≥ 0.3 m – Requires ε ≤ 4.8 μm

• For β* = 0.3 m

March 7, 2012


Multiple Beam Paths• Start with four beam paths separated by

roll angle of 90o

• Want to be away from path which could hit jet (or apparatus)– Want to be 45o from this path

• Will investigate the distance between beam centers

• Beam Paths’ Rolls:– 50.4o, 140.4o, 230.4o and 320.4o

March 7, 2012


Four Beam Paths

March 7, 2012

8m to IP 0.5m to IP

Distance to jet 0.5m to IP


X vs Y at Different Z

March 7, 2012


X vs Y at Different Z

March 7, 2012

-3m -4m -5m

-6m -7m -8m


Distance Between Beam Paths

March 7, 2012

Distance from “opposite” paths

Distance from nearest paths

σrms


Summary

March 7, 2012

Extras

March 7, 2012 Gollwitzer -- Proton Delivery to Target 25

proton delivery to target keith gollwitzer accelerator division fermilab map 2012 winter meeting...

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