R. Garoby June 23, 2005

Introduction SPL+PDAC example Elements of comparison Linacs / Synchrotrons

LINAC-BASED PROTON DRIVER

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Introduction

All proton driver begin with a linear accelerator. In a Linac-based driver, all acceleration is done in the Linac. However a fixed energy synchrotron is still needed for accumulation and bunch compression.

At low energy, it makes sense to only accelerate in a linac. Progress in sc resonators are reducing cost. However, at high energy (>5-8 GeV ?), a linac will anyhow be too costly.

What is the limit energy for selecting acceleration in the synchrotron ?

Other arguments ?

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SPL & PDAC [1/3]

Ion species H-

Kinetic energy 3.5 GeV

Mean current during the pulse 40 (30 ?) mA

Mean beam power 4 MW

Pulse repetition rate 50 Hz

Pulse duration 0.57 (0.76 ?) ms

Bunch frequency 352.2 MHz

Duty cycle during the pulse 62 (5/8) %

rms transverse emittances 0.4 mm mrad

Longitudinal rms emittance 0.3 deg MeV

SPL (CDR2) characteristics

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SPL main goals:

- increase the performance of the CERN high energy accelerators (PS, SPS & LHC)

- address the needs of future experiments with neutrinos and radio-active ion beams

H-

RFQ RFQ1 chop. RFQ2DTL-CCDTL-SCL 0.65 0.8 1

dump

Source Front End Normal Conducting Superconducting

95 keV 3 MeV 180 MeV 3.5 GeV

40MeV 90MeV

10 m 83 m ~ 350 m

Stretching andcollimation line

3.5 GeV to PS &Accumulator Ring(Neutrino Facility)

Debunching

400 MeV

chopp.

LINAC 4

352 MHz 704 MHz

900 MeV

1

1 - 2 GeV toEURISOL

SPL CDR2 Preliminary Layout 15.3.2005Work in progress!

The present R&D programme concentrates on low-energy (Linac4) items, wherever possible in collaboration with other laboratories.

SPL & PDAC [2/3]

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[Extrapolation from PDAC based on the SPL CDR-1]

Mean beam power 4 MW

Kinetic energy 3.5 GeV

Pulse repetition rate 50 Hz

Pulse duration 1.66 s

RF frequency 44.02 MHz

Number of bunches (buckets) 68 (73)

Number of protons per pulse (per bunch) 1.43 E14 (2.1 E12)

Number of turns for injection 345

rms normalized transverse emittances 50 mm mrad

Longitudinal emittance 0.2 eVs

SPL & PDAC [3/3]

SPL (CDR2) + PDAC characteristics

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Elements of comparison [1/2]

Domain Issue of interest QuestionPhysics Fit to the requirements for the secondary

beamSpecifications

Synergy with other physics needs Identification & specs.

Upgrade potential Identify

Time to full performance / risk Estimate

Economics Global economical optimum at construction

Cost as a function of energy & rate at fixed beam power

Minimal cost of exploitation (electricity, radioprotection, maintenance)

Power efficiencyReliabilityMaintenance needs Radioprotection issues

Management Possibility of a staged implementation Study possibilities

Share the efforts with other teams working for other goals

List of possibilities

Exploit/enrich available competence List

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Domain Issue of interest Linac SynchrotronsPhysics Fit to the requirements for the

secondary beam< 8 GeVShorter bunch distanceCycling rate (adjacent bursts ?)

Higher energyLarger bunch distanceCycling rate ~ 10 Hz >15 GeV

Synergy with other physics needs RIBs + injector for HEP

~ injector for HEP

Upgrade potential Large (power, users) Small

Time to full performance / risk Moderate/small ?

Economics Global economical optimum at construction

To be studied

Minimal cost of exploitation (electricity, radioprotection, maintenance)

To be studied

Management Possibility of a staged implementation

Yes (energy, power) ?

Share the efforts with other teams working for other goals

Yes (ADS, ILC, …) ?

Exploit/enrich available competence

To be studied

Elements of comparison [2/2]

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To be continued …

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ANNEX

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Cost comparison

Energy

Cost

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SPL - CDR2 baseline

RF• 704 MHz bulk Niobium cavities• 3 families of cavities : beta =0.5,0.85,1.0• gradients : 15, 18, 30 MV/m • 5, 6 and 7 cells per cavity

• Cold (2K) quadrupoles in the cryomodules, independently aligned from the cavities (to minimize cold/warm transitions and maximize real estate gradient). • Cryomodules of maximum length (between 10 and 15 m), containing n cavities and (n+1) quadrupoles. Diagnostics, steering etc. between cryomodules.• Length of the cavities limited by fabrication and handling considerations. Proposed number of cells per cavity is therefore 5, 6 and 7 for the three sections.• 2 MW max power /coupler • Standardisation of the design after 2 GeV

10 to 15 m

cryomodule

diagnostics,steering

quadrupole length to be determined, indicatively 300 mm (including bellows)

1m 1m

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HIP WG: long term alternatives

Present accelerator

Replacement accelerator

Improvement

INTEREST FOR

LHC upgrade

physics beyond CNGS

RIB beyond ISOLDE

Physics with k and

Linac2 Linac450 160 MeVH+ H- + 0 (if alone) 0 (if alone) 0 (if alone)

PSB

2.2 GeV RCS* for HEP

1.4 2.2 GeV10 250 kW

+ 0 (if alone) + 0 (if alone)

2.2 GeV/mMW RCS*

1.4 2.2 GeV0.01 4 MW

+++

(super-beam, -beam ?, factory)

+(too short beam

pulse)0 (if alone)

2.2 GeV/50 HzSPL*

1.4 2.2 GeV0.01 4 MW

++++

(super-beam, -beam, factory)

+++ 0 (if alone)

PS

SC PS*/** for HEP

26 50 GeVIntensity x 2

++ 0 (if alone) 0 +

5 Hz RCS*/**26 50 GeV0.1 4 MW

++ ++( factory)

0 +++

SPS1 TeV SC SPS*/**

0.45 1 TeVIntensity x2

+++ ? 0 +++

* with brightness x2 ** need new injector(s)

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