Parameters of 2Parameters of 2ndnd SPL SPL feasibility studyfeasibility study

A.M.Lombardi A.M.Lombardi

(reporting for the working group)(reporting for the working group)

ContentsContents what has changedwhat has changed with respect to CDR1 with respect to CDR1

[=conceptual design report][=conceptual design report]

frequencyfrequency/ length /RF power/reliability and cost/ length /RF power/reliability and cost

energyenergy and synergy and synergy

contributors to CDR2contributors to CDR2

planning and conclusionsplanning and conclusions

CDR1 baselineCDR1 baseline

SPL-CDR1 design was based on re-using SPL-CDR1 design was based on re-using the de-commissioned LEP RF system (50 the de-commissioned LEP RF system (50 Klystrons at 352 MHz) with new SC Klystrons at 352 MHz) with new SC cavities (beta < 1.0, Nb sputtered on Cu). cavities (beta < 1.0, Nb sputtered on Cu).

frequency fixed to 352 MHz,frequency fixed to 352 MHz, final energy fixed to 2.2 GeVfinal energy fixed to 2.2 GeV

Design tailored to the Neutrino Factory Design tailored to the Neutrino Factory

SPL block diagram (CDR 1)SPL block diagram (CDR 1)

SPL1 : 0 to 2.2 GeV in 650 meters

SPL beam characteristics (CDR 1)SPL beam characteristics (CDR 1)

Ion speciesIon species HH--

Kinetic energyKinetic energy 2.22.2 GeVGeV

Mean current during the pulseMean current during the pulse 1313 mAmA

Duty cycleDuty cycle 1414 %%

Mean beam powerMean beam power 44 MWMW

Pulse repetition ratePulse repetition rate 5050 HzHz

Pulse durationPulse duration 2.82.8 msms

Bunch frequency (minimum distance between bunches)Bunch frequency (minimum distance between bunches) 352.2352.2 MHzMHz

Duty cycle during the pulse (nb. of bunches/nb. of buckets)Duty cycle during the pulse (nb. of bunches/nb. of buckets) 62 (5/8)62 (5/8) %%

Number of protons per bunchNumber of protons per bunch 4.02 104.02 1088

Normalized rms transverse emittancesNormalized rms transverse emittances 0.40.4 mm mradmm mrad

Longitudinal rms emittanceLongitudinal rms emittance 0.30.3 deg MeVdeg MeV

Bunch length (at accumulator input)Bunch length (at accumulator input) 0.50.5 nsns

Energy spread (at accumulator input)Energy spread (at accumulator input) 0.50.5 MeVMeV

Energy jitter during the beam pulseEnergy jitter during the beam pulse < ± 0.2< ± 0.2 MeVMeV

Energy jitter between pulsesEnergy jitter between pulses < ± 2< ± 2 MeVMeV

push for changepush for change very good results on beta<1 700MHz bulk very good results on beta<1 700MHz bulk

niobium SC cavitiesniobium SC cavities

global view on the costing of 352 vs. 700 MHzglobal view on the costing of 352 vs. 700 MHz

2.2 GeV is a perfectly suited energy for a 2.2 GeV is a perfectly suited energy for a neutrino factory but not for a super beam neutrino factory but not for a super beam

A direct superbeam from a 2.2 GeV SPL does not appear to be the most attractive option for a future CERN neutrino experiment as it does not produce a significant advance on T2K. from SPSC-Villars04 recommendation

gradients at 700 MHzgradients at 700 MHz

Last test performed in CryHoLab (July 04):

5-cells 700 MHz ß=0.65 Nb cavity A5-01

from CEA/Saclay and IPN-Orsay

1E+08

1E+09

1E+10

1E+11

0 2 4 6 8 10 12 14 16 18 20

Eacc ( MV/m )

Q0

Vertical Cryostat (Fast Cooling)

Horizontal Test in CryHoLab (B1)

quench

from Stephane Chel, HIPPI04, Frankfurt, sep04

gradients at 700 MHzgradients at 700 MHz

Magnetic field limitation is a Magnetic field limitation is a basic physicsbasic physics constraint, for Nb the hard limit is of the Order constraint, for Nb the hard limit is of the Order of 200 mT.of 200 mT.

Electric field limitation is set by the Electric field limitation is set by the technological processes: technological processes: material, material, treatments, handling and cleanness. treatments, handling and cleanness. The The cavity shape has shown playing a crucial role cavity shape has shown playing a crucial role while frequency has very little, if any, while frequency has very little, if any, influence.influence.

surface field doesn’t depend on surface field doesn’t depend on frequency or betafrequency or beta

Paolo Pierini, INFN MILANO, DRAFT

the ratio of surface electric/magnetic field to accelerating the ratio of surface electric/magnetic field to accelerating field increases rapidly at decreasing betafield increases rapidly at decreasing beta

Paolo Pierini, INFN MILANO, DRAFT

the reduction of the beta of the cavity implies smaller inductive and capacitive

volumes, thus leading to higher surface fields.

Paolo Pierini, INFN MILANO, DRAFT

RF sources at 700 MHzRF sources at 700 MHz

1 MW foreseen for 2007 in Cryolab (saclay)1 MW foreseen for 2007 in Cryolab (saclay)

4MW available from Thales (priced already at 1 4MW available from Thales (priced already at 1 MEuros)MEuros)

there is a big jump (price, complexity) between a there is a big jump (price, complexity) between a pulsed source (up tp 2 msec 50Hz, i.e. 10% duty pulsed source (up tp 2 msec 50Hz, i.e. 10% duty cycle) and a CW one therefore power upgrades cycle) and a CW one therefore power upgrades above 10 MW can be achieved only by above 10 MW can be achieved only by increasing the final energy or the current increasing the final energy or the current

CDR2 baseline CDR2 baseline

10 to 15 m

cryomodule

diagnostics,steering

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

1m 1m

•3 families of cavity : beta =0.5,0.85,1.0

•gradients : 15, 18, 30 MV/m

•5, 6 and 7 cells per cavity

CDR2 baselineCDR2 baseline Use cold (2K) quadrupoles in the cryomodules, independently Use cold (2K) quadrupoles in the cryomodules, independently

aligned from the cavities (+: minimise cold/warm transitions and aligned from the cavities (+: minimise cold/warm transitions and maximize real estate gradient, TESLA experience, large maximize real estate gradient, TESLA experience, large aperture). aperture).

Use cryomodules of maximum length (between 10 and 15 m), Use cryomodules of maximum length (between 10 and 15 m), containing n cavities and (n+1) quadrupoles. Diagnostics, containing n cavities and (n+1) quadrupoles. Diagnostics, steering etc. between cryomodules.steering etc. between cryomodules.

The length of the cavities should be limited by fabrication and The length of the cavities should be limited by fabrication and handling considerations. The proposed number of cells per cavity handling considerations. The proposed number of cells per cavity is therefore 5, 6 and 7 for the three sections.is therefore 5, 6 and 7 for the three sections.

2 MW max power /coupler 2 MW max power /coupler

standardisation of the design after 2 GeV standardisation of the design after 2 GeV

CDR2 parametersCDR2 parameters

Ion speciesIon species HH--

Kinetic energyKinetic energy 3.53.5 GeVGeV

Mean current during the pulseMean current during the pulse 40 (30 ?)40 (30 ?) mAmA

Mean beam powerMean beam power 44 MWMW

Pulse repetition ratePulse repetition rate 5050 HzHz

Pulse durationPulse duration 0.57 (0.76 ?)0.57 (0.76 ?) msms

Bunch frequencyBunch frequency 352.2352.2 MHzMHz

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

rms transverse emittancesrms transverse emittances 0.40.4 mm mradmm mrad

Longitudinal rms emittanceLongitudinal rms emittance 0.30.3 deg MeVdeg MeV

CDR2 block diagramsCDR2 block diagrams

SPL2 : 0 to 3.5 GeV in 450 meters

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!

why not 704 from the start ?why not 704 from the start ?

acceptance at 100kV 700 MHz too smallacceptance at 100kV 700 MHz too small

focusing from the RFQ too weakfocusing from the RFQ too weak

Drift tube linac miniature dimensions Drift tube linac miniature dimensions

90 MeV is an optimal energy for the 90 MeV is an optimal energy for the frequency jumpfrequency jump

why not higher than 704 after few why not higher than 704 after few GeV?GeV?

GenLinWin - CEA/DSM/DAPNIA/SACM

Position ( m )300200100

Sy

nc

hro

no

us

ph

as

e (

de

g )

-4

-6

-8

-10

-12

-14

-16

-18

-20

-22

-24

-26

GenLinWin - CEA/DSM/DAPNIA/SACM

Position ( m )300200100

Sy

nc

hro

no

us

ph

as

e (

de

g )

-6

-8

-10

-12

-14

-16

-18

-20

-22

-24

-26

frequency jump needs longitudinal re-

matching, i.e. lower synchronous phase

Phase profile in SC LINAC at one single frequency

Phase profile in SC LINAC with frequency jump

1 1 frequency (MHz)frequency (MHz) 2 2 frequency (MHz)frequency (MHz) 3 3 frequency (MHz)frequency (MHz) Length Length (m)(m) Nb of cavityNb of cavity

704704 704704 410 410 (ESS)(ESS) 222222

704704 704704 407407 219219

704704 704704 704704 336336 129129

704704 704704 10561056 339339 156156

704704 10561056 382382 177177

704704 10561056 10561056 345345 154154

10561056 10561056 390390 189189

10561056 10561056 10561056 362362 173173

10561056 10561056 14081408 363363 187187

10561056 14081408 14081408 369369 194194

704704 10561056 14081408 339339 168168

preliminary optimisationpreliminary optimisation

by R. Duperrier, CEA Saclay

gradient/power/length/costgradient/power/length/cost total cost in a linac is generally proportional to lengthtotal cost in a linac is generally proportional to length

reliability is increased if the system has less components reliability is increased if the system has less components and the components are standardizedand the components are standardized

the fact of having in house the 352 RF power source is the fact of having in house the 352 RF power source is out weighted by the gain in lenght and reliability.out weighted by the gain in lenght and reliability.

352 bulk niobium cavity are not a good economical 352 bulk niobium cavity are not a good economical choicechoice

we can’t reach above 2.2 GeV by re-using the LEP we can’t reach above 2.2 GeV by re-using the LEP klystrons klystrons

energy and synergyenergy and synergy

SPL must be a multi-user facility. Each user has a SPL must be a multi-user facility. Each user has a specific request on intensity/beam power/energy. Whilst specific request on intensity/beam power/energy. Whilst intensity and beam power can be easily varied within the intensity and beam power can be easily varied within the same machine (change of source current, change of same machine (change of source current, change of duty cycle) the choice of the final energy must be such duty cycle) the choice of the final energy must be such as to accommodate the max number of possible users.as to accommodate the max number of possible users.

energy and synergyenergy and synergy

potential users :potential users :

Eurisol Eurisol betabeam betabeam

superbeam superbeam neutrino factory neutrino factory

CERN proton complexCERN proton complex

1-2 GeV 5 MW

above 2 GeV 4 MW

200 MeV, above 2 GeV

3.5 GeV 4 MW

CDR2 contributorsCDR2 contributors

The SPL study group at CERNThe SPL study group at CERN

CEA Saclay and INFN MilanoCEA Saclay and INFN Milano

HIPPI HIPPI

ISTC collaboration with Russian ISTC collaboration with Russian laboratories and nuclear citieslaboratories and nuclear cities

Stage 1: 3 MeV test placeStage 1: 3 MeV test place development and test of linac development and test of linac

equipment, beam characterizationequipment, beam characterization

Stage 2: Linac4Stage 2: Linac4 New linac replacing the present New linac replacing the present

injector of the PS Booster injector of the PS Booster (Linac2)(Linac2)

Front-end of the future SPL Front-end of the future SPL

improvement of the beams for improvement of the beams for physics (higher performance physics (higher performance and easier operation for LHC, and easier operation for LHC, ISOLDE etc.)ISOLDE etc.)

Stage 3: SPLStage 3: SPL New injector for the PS, replacing the PS BoosterNew injector for the PS, replacing the PS Booster New physics experiments using a high proton fluxNew physics experiments using a high proton flux

improvement of the beams for physics and possibility of new experimentsimprovement of the beams for physics and possibility of new experiments

3-stage approach3-stage approach

3 MeV test place ready

Linac4 approval

SPL approval

RF tests in SM 18 of prototype structures*

for Linac4

CDR 2

Global planningGlobal planning

ConclusionsConclusionsCDR2

•expected by the end of 2005

•cointaining a feasibility study for a 3.5 GeV Superconducting H- LINAC based on 700 MHz cavities

•results of the evolution of CDR1 with contribution from CEA-Saclay, INFN Milano, HIPPI, ISTC ....

Benefits of the SPLBenefits of the SPL

Performance upgrade of LHCPerformance upgrade of LHC much higher beam brightness: necessary much higher beam brightness: necessary

step towards an increased luminositystep towards an increased luminosity easier operation & higher reliabilityeasier operation & higher reliability

Second Generation Radio-active Ion Second Generation Radio-active Ion Beam Facility (EURISOL):Beam Facility (EURISOL): proton beam power x 1000proton beam power x 1000 flux of radio-active ions x 1000flux of radio-active ions x 1000

Neutrino physicsNeutrino physics ““super-beam (10 x beam power foreseen super-beam (10 x beam power foreseen

for the “CERN Neutrino to Gran Sasso” for the “CERN Neutrino to Gran Sasso” experiment)experiment)

““beta-beam”beta-beam” Neutrino factoryNeutrino factory

High energy physics with fixed targetsHigh energy physics with fixed targets Easier operation, higher reliability & higher Easier operation, higher reliability & higher

performance of the injector complexperformance of the injector complex

The beam from asingle SPL can betime-shared and

satisfy quasi-simultaneously

all these needs

Three stages are planned:Three stages are planned:

Stage 1: 3 MeV test placeStage 1: 3 MeV test place development and test of linac development and test of linac

equipment, beam characterizationequipment, beam characterization

StagesStages

Stage 2: Linac4Stage 2: Linac4 New linac replacing the New linac replacing the

present injector of the PS present injector of the PS Booster (Linac2)Booster (Linac2)

Front-end of the future Front-end of the future SPL SPL

improvement of the improvement of the beams for physics beams for physics (higher performance (higher performance and easier operation and easier operation for LHC, ISOLDE etc.)for LHC, ISOLDE etc.)

Stage 3: SPLStage 3: SPL New injector for the PS, replacing the PS BoosterNew injector for the PS, replacing the PS Booster New physics experiments using a high proton fluxNew physics experiments using a high proton flux

improvement of the beams for physics and possibility of new experimentsimprovement of the beams for physics and possibility of new experiments

SPL beam time structure (CDR 1)SPL beam time structure (CDR 1)

Fine time structure(within pulse)

Macro time structure