parameters of 2 nd spl feasibility study a.m.lombardi (reporting for the working group)
TRANSCRIPT
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