Beam transfer for NA neutrinos: Extraction from SPS, Transfer lines to targets

B.Goddard

F.Velotti, A.Parfenova, R.Steerenberg, K.Cornelis, W.Bartmann, V.Kain, E.Carlier, A.Alekou, M.Meddahi,

L.Jensen V.Mertens, A.Kosmicki, J.Osborne, I.Efthymiopoulos

Overview

• Extraction feasibility – studies and MD ongoing– Simulation and MD results

• Beamline feasibility – studies starting• Summary of input required from other study groups• BT WG objectives and some concerns• Conclusion

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Extraction feasibility studies• Reminder: very difficult to integrate kickers into LSS2, so

exploring the idea to use other SPS kickers :– LSS2 extraction using LSS1 MKP kicker (limited to ~100 GeV)

• Easiest to configure and test with beam (no interlocking issues)• Simulations competed, MD tests done, beam extracted to TT20• Active test program continuing

– LSS2 extraction using LSS6 MKE kicker (up to 450 GeV)• Constrained by interlocking and energy limits• Planning to test with HiRadMat beam (at 440 GeV), late in 2012• 400 GeV in theory easier than 100 GeV (beams x2 smaller)• Simulations in progress, MDs being organised

– LSS2 extraction using LSS4 MKE kicker (up to 450 GeV)• In reserve...

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Phase advances – 2012 opticsLSS1->LSS2: LHC Q26• lss1_deltamu = 4.1895 (68.22 deg) ;• kick_2 = 0.929 ;

LSS6->LSS2: CNGS• lss6_deltamu = 9.0675 (24.29 deg);• kick_6 = 0.411 ;

LSS6->LSS2: LHC Q26• lss6_deltamu = 8.8998 (323.94 deg);• kick_6 = -0.589 ;

LSS6->LSS2: LHC Q20 • lss6_deltamu = 6.8491 (305.60 deg);• kick_6 = -0.812 ;

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KickerLSS1

ExtractionLSS2

~1.2 km

Simulations – LSS1->LSS2Bump and extraction trajectories (110 GeV, 8 um, ±5 s envelopes)

Zoom in extraction regionIncluding orbit from quadrupole misalignments (100 mm)

Aperture quantification, with SPS orbit110 GeV Bumped beam

100 GeV Bumped beam

110 GeV Extr. beam

100 GeV Extr beam

5.1-5.2 s 3.7-3.8 s

5.7-5.8 s 4.5-4.6 s

SPS measurements (I) 4/09/2012: LSS1 – LSS2 phase advance checks

10 15 20 25 30 350

50

100

150

200

250

300

3508.00E+10

2.50E+10

8.00E+09

Linear lattice phase advance

Oscillation amplitude [mm]

Phas

e di

ffer

ence

BPM

H.1

20 t

o BP

MH

.216

[deg

]

• Phase advance scatters within ±15° around value expected from linear lattice (20.5°)

• No tune dependence on oscillation amplitude or intensity

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SPS measurements (II) 17/09/2012Extraction test

MKP

MST/MSE

TT20.BTVTT20.BTV

TED

LSS1: MKP

LSS2: MST

LSS2: MSE

SPS

TT20

TT20

1/6 of SPS circumference, 130 m of TT20

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Supercycle composition - dedicated

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LSS2 closed orbit bump

• New bump shape with huge 60 mm excursion in QFA216• Very small leakage (rms ~0.3 mm) – no losses or issues

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First fast extraction in LSS2• MKP kickers pulsed using timing event and pre-pulse (no beam from PS)• Beam extracted into TT20 using calculated settings

– MKP on at 52 kV for three generators– MST on at 0.5 mrad– MSE on at 1.92 mrad

• Needed then to trim MSE up by few % (as usual)

BTV.210026 BTV.210352

Aperture and loss scans • 4e11 p+, 110 GeV, blown up to 7 um.mrad to approach CNGS

parameters• Issue seen with too-fast bumper functions, corrected

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After bump function modification

Before correction

Orbit position at upstream TPST entrance [mm]

Loss

es [m

Gra

y]

Effect of bumper function correctionExtraction losses (extraction time 2400 ms)

Before correction

After correction

Losses from bump overshoot

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Losses with 7 um H/V beam emittance

Extraction losses (extraction time 2400 ms)Injection losses (likely vertical)

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Extracting 7 um.mrad with 10% more MKP kick strength (as for 100 GeV beam)

No measurable extraction losses (extraction time 2400 ms)

Managed to get SPS orbit acquisition for last turn

Some coupling into V? To understand

Other extraction aspects• Other feasibility aspects being considered:

– Interlocking and machine protection issues• Beam Interlock Controllers, interlocking logic, Energy Tracking• Conceptual solution already defined with interlocking team• All machine protection implications to be examined (MPP 28/09/12)

– Kicker HW upgrades needed for double extraction• Charging supplies, PFNs, cabling, …

– Kicker control updates also required• Pre-pulses, timing, cabling, …

– Extraction region BI for both fast and slow beams• Screens, BPMs, BLMs, BCTs

• No major feasibility issues identified to date – designing adequate machine protection will be the key issue

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Summary for “non-local” extraction• Concept shown to work, on paper and in machine.

– Clean extraction achieved (for low intensity beam only)

• MKP can extract 100-110 GeV in LSS2 with εn=7 μm– Allows 11 us extraction flat-top, with < 1 us rise time – RCPS upgrade

needed to make double extraction (like CNGS)– Losses scaled to CNGS intensity look same order of magnitude as

those seen now in LSS4 (higher intensity will only make things worse)– 100 GeV (kick 10% bigger) is more comfortable, but will need to

address the SPS dump “forbidden zone” (or use 102.3 GeV...)

• MKE kickers in LSS6 will be tested, will allow high energy (in principle to 450 GeV)– But their present rise time is 6-7 ms: cannot make double extraction.

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Beamline feasibility studies• TT20/21 upgrade for FE 100/400 GeV beam– Optics, aperture, powering, instrumentation, …

• New beamline sections to neutrino targets– Geometry, optics, layout, instrumentation, magnets,

powering, CV, access, civil engineering, transport, services, interlocks, vacuum, RP, …

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Beamline study status• Coordinates of targets defined, in first version– A.Kosmicki / J.Osborne 20120727 – EDMS# 1233951– Recent update with optimised target location/orientation

• Now iterating on these first layouts– More precise branching location and switch layout– More precise bending radii, first order geometry and

optics, beam parameters

• Constraints still to be finalised– Max/min beam energy, max/min beam emittances, dp/p,

bunch structure, any loss limitations, required beam parameters at targets, CE constraints, ...

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Branching from TT20: switch length needed

• Length scales with ~B.r• TT40/TT41 switch ~40 m long (400 GeV)• Will need ~10 m ‘free’ for 100 GeV beam

TT40/TT41 (CNGS/TI 8) 8x MBSG switch magnets, ~40 m

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Branching from TT20 • Needs to be well before splitter magnets

– Splitters will stay for slow extracted beams– Very high radiation in magnets and tunnel (CE probably affected?)– Optics progressively more and more screwed up

• Before 16 mrad a2 H bend is useful for extracting beam from tunnel

• Before 110 mrad j2 V bend not so good, but probably feasible

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Branching from TT20 at 100 GeV

Switch magnet here ?

~5 mfree

a2j2 j2

j2 j2 ~7 mfreeB.Goddard

Input still needed from other “study teams”

• Beam parameters at targets (from target designers)– sxsy, axay,DxDy

– Beam position jitter tolerance, required tuning range (s)– Needed for optics design

• Civil engineering constraints (from civil engineering)– Junction cavern lengths, tunnel separations, depth constraints, modifications of

existing structures, ..– Needed to define primary beamline layout

• Beam characteristics from injectors and SPS (from OP)– Intensity, transverse emittance, dp/p– Needed for aperture definition, simulations, losses, instrumentation, ..

• Estimates of required POT (from experiments)– Per year, and over facility lifetime– Needed for magnet dose/activation/decommissioning estimates, materials

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Beam transfer study WG objectives

• Assume scope is (for now) limited to feasibility study• Objectives:

– Complete feasibility study and MD in SPS to show that non-local fast extraction can work, and identify best concept

– Define conceptual design for extraction from SPS and beamlines to targets, including first layout details and key aspects for CE

– Define basic technical requirements for all associated HW systems, infrastructure and services

– Assemble cost and resource estimates for extraction and beamline systems to targets, from systems groups

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What is the assumed timeline for implementation?

• Need input on baseline for timeline: dates for– Completion of feasibility study– Decision on implementation– Construction and installation dates– Commissioning and operation dates

• Important, because many technical groups completely saturated (e.g. no cabling activity possible until LS2)

• The time deadlines clearly affects the feasibility, depending on required development, construction, cabling etc.

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Open questions /discussion• To extend scope of present effort need “official” recognition

of this activity as a study. When is this expected? Will this activity be included in MTP/APT etc.? Manpower priorities? Budget codes for design effort, ...?

• Need urgently an overall mandate, scope and structure as a lot of information and work is needed from other teams, and cannot do this unofficially.

• Potential overlap or competition for resources with other studies to manage correctly – for example AWAKE re-use of CNGS beamline or components, LAGUNA layouts, LIU proposed upgrade of MKPA/C kickers for ions

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Conclusions• Fast extraction from LSS2 (still) looks feasible

– Works on paper, and first tests in SPS encouraging– MDs and studies ongoing– Should be able to conclude in 4-6 weeks– Machine protection will be main ‘feasibility’ issue

• Beamline studies in progress– Target coordinates known, other input still needed (especially beam

parameters at target)– Branching from well before TT20 splitter seems mandatory– Space ~150 m upstream – about 8 m vertical offset– Will need some time (6-8 weeks?) for iteration with CE experts to

produce a first ‘working’ version of the layout which will allow details of magnet types etc. to be known

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Target coordinates v2.0

P0 PS 2000000.000 2097792.650 2433660.000P1 (SBL2NA - Connection point) 636149.860 4308151.730 2442937.450P2 (2eme point sur beam existant) 641179.500 4351110.490 2442921.710P3 (SBL2NA) 612323.100 4637880.805 2442819.280P4 (SBL2NA) 929503.163 6206127.216 2440319.282P5 (CN2PY) 613396.065 4637918.306 2422819.281P6 (CN2PY) 500940.075 5417612.069 2283423.129

A.Kosmicki/J.Osborne