11 october 2006basic layout of ler g. de rijk1 basic layout of ler the basic idea vlhc type...

11 October 2006

Basic Layout of LER G. de Rijk 1

Basic Layout of LERBasic Layout of LER

The basic ideaThe basic idea VLHC type magnetsVLHC type magnets LER in the LHC tunnelLER in the LHC tunnel LayoutLayout LER experiment bypass and injection schemeLER experiment bypass and injection scheme SPS-LER-LHC injection sequenceSPS-LER-LHC injection sequence

11 October 2006


The basic ideaThe basic idea LER is a two beam machineLER is a two beam machine Two-in-one superferric combined function magnets Two-in-one superferric combined function magnets Inject beam from SPS into LER Inject beam from SPS into LER Accumulate and shape the two beams in LERAccumulate and shape the two beams in LER Accelerate from 0.45 TeV up to 1.5 TeVAccelerate from 0.45 TeV up to 1.5 TeV Transfer the two beam simultaneously in a single Transfer the two beam simultaneously in a single

turn transfer into the LHCturn transfer into the LHCSo:So: Beam coasting time in LHC at injection energy Beam coasting time in LHC at injection energy

(0.45 TeV) is reduced to the minimum (~10 ms)(0.45 TeV) is reduced to the minimum (~10 ms) Starting at 1.5 TeV the LHC can ramp fasterStarting at 1.5 TeV the LHC can ramp faster Beam is coasting at 0.45 TeV in LER in a “clean” Beam is coasting at 0.45 TeV in LER in a “clean”

machingmaching

11 October 2006


Pre-accelerator LERPre-accelerator LER Pre-accelerator of Pre-accelerator of

0.45 TeV => 1 TeV-0.45 TeV => 1 TeV-1.5 TeV in the LHC 1.5 TeV in the LHC tunnel.tunnel.

Ring of small Ring of small transverse transverse dimensions dimensions

Cheap magnetsCheap magnets

Using VLHC Using VLHC ‘pipetron’ magnets.‘pipetron’ magnets.

11 October 2006


Pipetron - VLHC magnets Pipetron - VLHC magnets FNALFNAL

0.45 TeV injection at 0.48 T0.45 TeV injection at 0.48 T 1.5 TeV top at 1.595 T 1.5 TeV top at 1.595 T

(72kA)(72kA) Gradient ~ 3%Gradient ~ 3% Enlarged magnet aperture Enlarged magnet aperture

v 28 mm x h 40 mmv 28 mm x h 40 mm

VLHC

LER

H. Piekarz et al.

11 October 2006


Pipetron - VLHC magnets Pipetron - VLHC magnets FNALFNAL

1 m prototype tested at 1 m prototype tested at FNALFNAL

Reported at MT19Reported at MT19

H. Piekarz et al.

11 October 2006


Feasibility study - Feasibility study - tunnel spacetunnel space

Fits above the LHC ring at a Fits above the LHC ring at a 1.35 m beam-to-beam 1.35 m beam-to-beam vertical distancevertical distance

(some cabling exceptions in (some cabling exceptions in straight sections)straight sections)

11 October 2006



11 October 2006


Layout (1)Layout (1) Arc cells match the LHC cell lengthArc cells match the LHC cell length 4 Combined function magnets (12 m) per half cell 4 Combined function magnets (12 m) per half cell

Bmax 1.595 T, G = ± 4.969 T/mBmax 1.595 T, G = ± 4.969 T/m Dispersion suppressor with combined function Dispersion suppressor with combined function

magnets (8 m).magnets (8 m). Short straight sections with corrector magnets are Short straight sections with corrector magnets are

similar to those for VLHCsimilar to those for VLHC Straight sections have 4 m long quadsStraight sections have 4 m long quads Low beta insertion is common with the LHCLow beta insertion is common with the LHC

talk by J. Johnstone FNALtalk by J. Johnstone FNAL

11 October 2006


The challenge: Experiment The challenge: Experiment bypassesbypasses

There are:There are:

2 large (ATLAS & 2 large (ATLAS & CMS) CMS)

2 less big (ALICE & 2 less big (ALICE & LHCb) LHCb)

experiments to experiments to bypassbypass

For this study we For this study we assume that after assume that after an upgrade only an upgrade only ATLAS and CMS ATLAS and CMS will remainwill remain

11 October 2006


Experiment bypass optionsExperiment bypass options1.1. Bypass the experiments in a tunnelBypass the experiments in a tunnel

typically be at least 2 x 300 long Digging a bypass requires to empty the main tunnel at the

junctions An extra shaft is probably needed for each bypass At least a year shutdown Very costly: >20 MCHF per tunnel Remark: the optics could be very problematic

2.2. Bypass the experiments through the detectorsBypass the experiments through the detectors Drilling a hole through the detectors is probably a very bad idea There is a hybrid option with (1) passing in between the muon

chambers : to be studied later Remark: the optics could be very problematic

3.3. Bypass the experiments through the LHC beampipeBypass the experiments through the LHC beampipe Bump beam down (and back up) into beam experimental beam

pipe Study concentrates on this option

11 October 2006


Injection / bypass schemeInjection / bypass scheme

Use existing Use existing injection injection channelchannel

Fast switched Fast switched transfer lines transfer lines in IP1 and IP5in IP1 and IP5

RF, dump and RF, dump and cleaning cleaning separate from separate from LHCLHC

11 October 2006


Injection / bypass scheme (2)Injection / bypass scheme (2)

Beam train of 89 Beam train of 89 s + gap of 3 s + gap of 3 ss To inject in LHC switch Fast Switching Dipole off during 3 To inject in LHC switch Fast Switching Dipole off during 3 s gaps gap The following FSD go off in sequence when the gap passesThe following FSD go off in sequence when the gap passes

LER ops:LER ops:D and FSD onD and FSD on

LHC ops:LHC ops:D and FSD offD and FSD off

11 October 2006


Transfer between LER and Transfer between LER and LHC (1)LHC (1)

Horizontal separation 150 ==> 0 mmHorizontal separation 150 ==> 0 mm Vertical separation 1350 ==> 0 mmVertical separation 1350 ==> 0 mm

- One set of fast One set of fast switched dipoles switched dipoles only at the LHC only at the LHC side of a transfer side of a transfer lineline

- horizonal bend 2 horizonal bend 2 is made by tilting is made by tilting the vertical bends the vertical bends

Talks: J. Johnstone and H. Piekarz

11 October 2006


Transfer between LER and Transfer between LER and LHC (2)LHC (2)

Talks: J. Johnstone and H. Piekarz

11 October 2006


Timing sequenceTiming sequence Injection plateau of ~ 400 sInjection plateau of ~ 400 s Ramp up time from 0.45 TeV to 1.5 TeV is 300 s.Ramp up time from 0.45 TeV to 1.5 TeV is 300 s. Fast Pulsed Dipoles ramp down in 3 Fast Pulsed Dipoles ramp down in 3 ss

11 October 2006


Timing sequenceTiming sequence Neighbouring fast switching magnets switch off at Neighbouring fast switching magnets switch off at

different timesdifferent times Timing sequencing and magnetic decoupling of Timing sequencing and magnetic decoupling of

FSDs are importantFSDs are important

11 October 2006


Machine set-up optionMachine set-up option

After an LHC dump:After an LHC dump: If the low beta insertions can be ramped down fast Then LER can setup while the LHC main magnets are still

ramping down

11 October 2006


Conclusing remarksConclusing remarks LER fits into the LHC arcs (with ease).LER fits into the LHC arcs (with ease). The main two-in-one superferric combined function The main two-in-one superferric combined function

magnets are of an existing technologymagnets are of an existing technology The bypass through the experimental beam pipe is The bypass through the experimental beam pipe is

possible.possible. Dipole magnets which can be switched off fast, are Dipole magnets which can be switched off fast, are

crucial.crucial. LER is a dedicated injector for the LHC.LER is a dedicated injector for the LHC. A future application is LER as DLHC injectorA future application is LER as DLHC injector

11 october 2006basic layout of ler g. de rijk1 basic layout of ler the basic idea vlhc type...

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