Proton Delivery to Target Keith Gollwitzer Accelerator Division

Proton Delivery to Target Keith Gollwitzer Accelerator Division Fermilab MAP 2012 Winter Meeting March 7, 2012

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 first-work done by Eliana Gianfelice. Wendt and myself – Simple Tracking, Matrices, Spreadsheets. . March 7, 2012 Gollwitzer -- Proton Delivery to Target 2

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 • Continue last few steps to empty rings – Effectively 45 or 60 Hz March 7, 2012 Gollwitzer -- Proton Delivery to Target 3

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 Gollwitzer -- Proton Delivery to Target 4

Muon Collider Trombone March 7, 2012 Gollwitzer -- Proton Delivery to Target 5

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 (ids 120 h) and varies many parameters to optimize the number of usable muons (uses 8 Ge. V proton beam) See Sunday Ding talk for further work March 7, 2012 Gollwitzer -- Proton Delivery to Target 6

PRST-AB Optimization Proton Beam is Gaussian Proton Beam Radius (rms) is 30% of jet radius Solenoid Field is 20 T in interaction region Jet is in y-z plane Jet/Solenoid angle: 96. 7 mrad Jet/Proton Beam angle: 27 mrad at IP Jet radius: 0. 4 cm Proton Beam Energy: 8 Ge. V March 7, 2012 Gollwitzer -- Proton Delivery to Target Ding Talk has smaller Jet/Proton bean angle 7

PRST-AB Optimization • Initial optimization is with beam coming from below – Roll angle of 180 o • Investigate proton beam azimuthal approach – Propagate proton beam back to -75 cm – Helical paths for beam to always intersect at (0 cm, -37. 5 cm) – Investigated 15 paths with different roll angles into the jet March 7, 2012 Gollwitzer -- Proton Delivery to Target 8

Solenoid Information IDS 120 h Proton Beam in Solenoid field March 7, 2012 “The Target System Baseline”, Kirk & Mc. Donald (Feb 4, 2011) Gollwitzer -- Proton Delivery to Target 9

Solenoids Layout r (cm) IDS 120 h z (cm) March 7, 2012 Gollwitzer -- Proton Delivery to Target 10

Field on axis B_z (T) z (cm) March 7, 2012 Gollwitzer -- Proton Delivery to Target 11

Radial field B_r (T) r = 7 cm From Ding March 7, 2012 Gollwitzer -- Proton Delivery to Target z (cm) 12

Reproducing PRST-AB Beam Paths -75 cm to -37. 5 cm p 14 p 2 p 11 p 5 March 7, 2012 Gollwitzer -- Proton Delivery to Target 13

Clearance is in beam sigmas at -75 cm Beam Distance from Jet March 7, 2012 Gollwitzer -- Proton Delivery to Target 14

X & Y vs Z March 7, 2012 Gollwitzer -- Proton Delivery to Target 15

X vs Y 0. 5 m to IP 8 m to IP March 7, 2012 Gollwitzer -- Proton Delivery to Target 16

Single Beam Path • Optimization of muons per roll angle results in roll of 264 o • Roll of 95. 4 o results in hitting jet twice Z = -123 and -37. 5 cm March 7, 2012 Gollwitzer -- Proton Delivery to Target 17

Beam Size • At IP, σrms = 0. 12 cm • Optimization shows that β* ≥ 0. 3 m – Requires ε ≤ 4. 8 μm • For β* = 0. 3 m Note that Ding’s talk argues for larger β* March 7, 2012 Z [m] σrms [cm] -3 1. 06 -4 1. 45 -5 1. 85 -6 2. 25 -7 2. 65 -8 3. 05 Gollwitzer -- Proton Delivery to Target 18

Multiple Beam Paths • Start with four beam paths separated by o roll angle of 90 • Want to be away from path which could hit jet (or apparatus) – Want to be 45 o from this path • Will investigate the distance between beam centers • Beam Paths’ Rolls: 50. 4 o, 140. 4 o, 230. 4 o and 320. 4 o March 7, 2012 Gollwitzer -- Proton Delivery to Target 19

Four Beam Paths 0. 5 m to IP 8 m to IP Distance to jet March 7, 2012 0. 5 m to IP Gollwitzer -- Proton Delivery to Target 20

X vs Y at Different Z March 7, 2012 Gollwitzer -- Proton Delivery to Target 21

X vs Y at Different Z -3 m -4 m -5 m -6 m -7 m -8 m March 7, 2012 Gollwitzer -- Proton Delivery to Target 22

Distance Between Beam Paths Distance from “opposite” paths Distance from nearest paths σrms March 7, 2012 Gollwitzer -- Proton Delivery to Target 23

A quick look at separating beams After translation and rotation of coordinate system: Quick exchange with a magnet builder about a 4 -way dipole. Response: - Reduce field to <1. 5 T der l i u tb e n - Increase separation to > 80 cm ag m - Reduce beam size ith w s Pas t s Fir March 7, 2012 Gollwitzer -- Proton Delivery to Target 24

Discussion - 1 • Beam Size – At IP, current requirement is σbeam/rjet = 0. 3 • Should this be optimized – Larger better – Rings emittances should be studied to see what can be expected. – Then the largest affordable β* can be used for further work • Beam/Jet Angle – Larger better for MC • Better beam separation – Should be optimized as a function of roll angle March 7, 2012 Gollwitzer -- Proton Delivery to Target 25

Discussion - 2 • Jet – Interact with Target Station group to understand jet apparatus constraints • Neutrino Factory – Will need to design location of final magnetic elements as a function of beam size and emittance. • Muon Collider – Limit to four bunches – Need to have serious discussion with magnet designers about possibilities • Translate beam spacing into beam/jet angle constraint March 7, 2012 Gollwitzer -- Proton Delivery to Target 26