Beam Instrumentations: Requirements for Proton and Electron Beams

C. Bracco, E. Gschwendtner, B. Goddard, M. Meddahi, A. Petrenko, F. Velotti

Acknowledgements: WP3 and WP4 members, P. Muggli and A. Caldwell

Outlines Introduction

Layout and optics Electron and proton beam integration (side-injection, on-axis injection)

Electron beam line Beam characteristics Lattice Wish list for diagnostics

Proton beam line Beam characteristics Lattice Wish list for diagnostics

Summary

Reminder

Three beams into the game!

7.16 %

Phase 1 (2016): protons + laser beam prove SMI

Phase 2 (2017): protons + laser + electron beam probe acceleration

Proton and Electron Beam Common beam line last ~4.4 m before plasma cell

C. Magnier, F. Galleazzi

Proton and Electron Beam15

-25

mm

20 m

m

10 m

40 m

m

<0.5 mm

p

e

10 m

40 m

m

pe

40 m

m

Side injection

On axis injection

20 m

m24

mm

s=801mOff axis!!

Electron Beam Line

Momentum [GeV/c] 10-20 (nom. 15)

# bunches 1

p+ per bunch 2.0 × 109

Current [nC] 0.3

Norm. Emittance [mm mrad]

2

e-

e-p+

On-axis inj

Quads inside the connection tunnel

Final triplet

* *tot. envelope: 2x Envelope Hor/Verbeam pipes Ø: 15-25 mm

F. m. Velotti

Electron Beam Line

1. Emittance measurement at beginning of the line Available space (~50 cm) between elements in the

connection tunnel Vertical dispersion non-zero

2. Beam size at the plasma cell3. BPMs for correction assuming 1vs1 strategy

14 (1 per quad) + 2 before the plasma cell 6 of them in the common part with p+

4. Momentum measurements Spectrometer at the end of RF gun? At one of the h-

bends?

5. Bunch length measurements 6. Current measurements

F. m. Velotti

Electron Beam Line

1. Emittance measurement at beginning of the line Available space (~50 cm) between elements in the

connection tunnel Vertical dispersion non-zero

2. Beam size at the plasma cell3. BPMs for correction assuming 1vs1 strategy

14 (1 per quad) + 2 before the plasma cell 6 of them in the common part with p+

4. Momentum measurements Spectrometer at the end of RF gun? At one of the h-

bends?

5. Bunch length measurements 6. Current measurements

Measurements

Precision Position

Emittance +/- 200 m Connection tunnel

Beam size +/- 50 m Before plasma cell

Beam position +/- 200 m+/- 50 m

@ quads and before plasma cell

Momentum +/- 7.5 keV horizontal bends

Current < 1% Before/after plasma cell

F. m. Velotti

Proton Beam

CNGS AWAKENominal Setup

Momentum [GeV/c] 400 400 400

# bunches 2100 1 1

p+ per bunch 1.05 × 1010 3 × 1011 5 × 109

Repetition rate [s] 6 30 ---

Norm. Emittance [mm mrad]

~8 2-3.5 1-2

Specifications (based on LHC TL and HiRadMat requirements) for the unchanged part of the beam line (everything installed upstream of BTVG.412108) :

•BPM:• 0.2 mm total accuracy • Resolution: 0.1 mm (within 20 mm radius)

•BCT:• 1->2% absolute precision

•BTV: • Beam size precision: 0.1 mm

•BLM:• Detect local loss of 5e8 charges

Diagnostics for single bunches!

~74 times lower intensity than

CNGS

Changes in the Proton Beam Line

Instrumentation presently installed:

BTVG.412108BPG.412211BLM.412243BPG.412321BPG.412424BTVG.412424BFCT.412425BTVG.412434BLMr.412445/BLMl.412445BPG.412444BTV.412445BPKG.412449

Target Area (not possible to reuse)

Possible to reuse? (provided required modifications)

~ 90 m

What is Needed in the “New Line”?

BPG

BPG

BPG

BPG

BPG

BPG

What is Needed in the “New Line”?

BPG

BPG

BPG

BPG

BPG

BPG

BPG

Proton and Laser Beam

Plasma cell

Not real bottleneck

Laser

Prot

on

± 8 mm

± 6 mm

~7 mm (it must be > 5 mm!)

BPG

new

BPG

BPG

new

BPG

What is Needed in the “New Line”?

BPG

BPG

BPG

BPG

BPG

BPG

BPG

BPG

BPG

BPG

BPG

Required Pointing Accuracy

Required Pointing Accuracy

Beam Envelope at BPMs

s**[m]

Tot. Env. X[mm]

Tot. Env. Y[mm]

Beam Pipe[mm]

Accuracy[mm]

BPG.412211 749.420 16.5 31.1 60 0.2

BPG.412321 777.575 24.0 14.0 50* 0.2

BPG.412424 785.025 15.0 13.9 50* 0.2

BPG.412xxx 788.025 13.2 12.3 50* 0.2

BPG.412xxx 798.825 7.0 6.7 40 0.05

BPG.412xxx 805.325 4.8 4.8 20/40*** 0.05

BPG.412xxx 815.825 9.2 8.3 40 0.05

BPG.412xxx 822.825 13.4 12.0 40 0.05

** end position * 50 mm (inner diameter) vacuum chamber for new B190 dipoles, to be checked if still compatible with 60 mm aperture at BPMs (J. Hansen)*** side injection/ on axis injection

Downstream of plasma cell

Interlocked!

Extraction from SPS must be stopped if beyond tolerances: 100 m and 15 rad

What is Needed in the “New Line”?

BTV

BTV

BTV

BTV

BTV

Proton Beam Line Optics Requirements

Round beam with a beam size @ plasma cell entrance 1 = 200 ± 20 m

Achieved: 1 = 202 m

Beam Envelope at BTVs

S [m]

Tot. Env. X[mm]

Tot. Env. Y[mm]

Beam Pipe[mm]

Accuracy[mm]

BTV.412108 740.215 13.2 30.6 60 0.2

BTV.412xxx 804.675 4.8 4.8 20/40* <0.05

BTV.412xxx 820.675 12.1 10.8 40 <0.05Downstream of plasma cell

The last two BTVs have to be used also for the proton and laser beam setup (position: two beams coaxial) a screen has to be added for the laser beam (reduced power during setup, see Mikhail’s talk)

The Monitor downstream can be used also for the e-beam

Position and beam size measurements

* side injection/ on axis injection

What is Needed in the “New Line”?

BLM

BLM

BLM @ location of vertical bottleneck (5e8 charges)BCT: 1-2% absolute precision

BC

T

Summary 1/2 Electron beam line:

Completely new diagnostics to measure: Emittance Energy Beam size @ plasma cell Beam position Bunch length Current

Proton beam line: Adapt existing diagnostics for AWAKE operation (1 bunch) up to

BTVG.412108 (excluded) + reuse part of remaining diagnostics Five additional BPM Two additional monitors for beam size measurements of the p

beam and position measurements for p and laser

Summary 1/2

Main challenges: Coexistence of the e an p beams Reduced beam pipe diameters (15-24 mm) Almost no space around the beam pipes in common part of

the lines (we’ll try to optimize the lattice): How to implement pickups for position measurements? How to perform beam profile measurements?

Required very high accuracy in position measurements for p and laser beam

Low electron energy and current The option of having a unique design for on axis and side-

injection is being evaluated: double diagnostics at the end of the line…..