Post on 18-Oct-2020
Accelerator SummaryAccelerator Summary
Geoffrey KrafftJefferson Laboratory
Old Dominion University
Thomas Jefferson National Accelerator Facility Page 1
1st International Workshop on Accelerator Driven Sub-Critical Systems and Thorium Utilization
OutlineOutline
• Basic Requirements of Proton ADS Drivers• SRF Accelerators as ADS Drivers
• Starting Points in US• Comments on Reliability
C S ff• Comments on SRF Efficiency• ADS Experiments
Alt ti D i• Alternative Drivers• Summary
Thomas Jefferson National Accelerator Facility Page 2
1st International Workshop on Accelerator Driven Sub-Critical Systems and Thorium Utilization
Range of Missions for Accelerator Driven SystemsyTransmutation Demonstration Industrial-Scale
T t ti
Industrial-Scale Power
G ti /
Industrial-Scale Power
and Experimentation
Transmutation Generation w/ Energy Storage
Generation w/o Energy Storage
A l t b T t ti f D li t D li t•Accelerator sub-critical reactor coupling•ADS technology
•Transmutation of M.A. or Am fuel•Convert process heat to another
•Deliver power to the grid•Burn MA (or Th) fuel
•Deliver power to the grid•Burn MA (or Th) fuel
and components• M.A./Th fuel studies
form of energy •Incorporate energy storage to mitigate long interruptions
Time Beam Trip Requirements Accelerator
p
S. Henderson, thisk h
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Time, Beam-Trip Requirements, Accelerator Complexity, Cost
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Accelerator Technology - Requirements
Transmutation Demonstration
Industrial Scale Facility driving single
Industrial Scale Facility driving multiple
(MYRRHA [5]) subcritical core (EFIT [10])
subcritical cores (ATW [11])
Beam Energy [GeV] 0.6 0.8 1.0
Beam Power [MW] 1.5 16 45
Beam current [mA] 2.5 20 45
Uncontrolled Beamloss
< 1 W/m < 1 W/m < 1 W/m
Fractional beamlossat full energy
< 0.7 < 0.06 < 0.02at full energy (ppm/m)
S. Henderson, thisk h
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P. Ferguson, thisk h
Thomas Jefferson National Accelerator Facility Page 5
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Beam Power Frontier for ProtonsCentral challenge at the beam power frontier is controlling beam loss to minimize residual activation1 nA protons at 1 GeV, a 1 Watt beam, activates stainless steel to 80 mrem/hr at 1 ft after 4 hrs
Courtesy J. Wei
M. Champion, thisk h
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M. Champion, thisk h
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1 GeV Superconducting Proton Linac for ADS Demonstration
Power level of the overall demonstration system is a topic for ongoing research Power level of the overall demonstration system is a topic for ongoing research As an example, for the initial design we assume 10 mA beam which results in
10 MW system at 1 GeV
High‐energy sectionMedium‐energy sectionFront end
ll l
Low‐energy section
Ion sourceNC RFQ
QWRHWRSR
Elliptical
SRElliptical Frequency of the HE section is
~700 MHSR ~700 MHz
SNS SC cavities
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LANL LEDA RFQCourtesy D. Schrage
SNS SC cavitiesCourtesy J. GalambosP. Ostroumov, this
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500 MeV Front End Based on TEM-class SC Cavities
IS RFQ/MEBT QWR HWR TSR 1 TSR 2
Beam energy – 500 MeV Beam current ‐ 10 mA
Operation temperature – 2K Dynamic cryogenic load – 1.1 kW
IS RFQ/MEBT QWR HWR TSR-1 TSR-2
1 m 6 m 10 m 25 m 51 m 116 m25 k V 1 5 M V 12 M V 66 M V 160 M V 500 M V25 keV 1.5 MeV 12 MeV 66 MeV 160 MeV 500 MeV
Cavity type G # of # of Energy Length Max. RF powercavities cryomod. MeV m kW per cavity
QWR 0.1 5 1 12 4 30
HWR 0.22 19 2 66 15 30
TSR‐1 0.52 20 4 160 26 60
TSR‐2 0.65 39 13 600 65 100
TOTAL 83 21 110
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TOTAL 83 21 110
P. Ostroumov, this workshop
SRF SRF LinacLinac Costs are “Knowable”Costs are “Knowable”
3000
SNS Cost M$ per Cryomodule in 2010 Dollars based on amortizing R&D and PM Cost over 23 High & Med Beta Cryomdoules
* R&D/PM includes Refrigeration plant
2500
1500
2000
Cryomodule
R&D
1000
Project Services
0
500
Labor M&S Total Cost R. Rimmer, this
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Range of Parameters for ADS
Transmutation Demonstration
Industrial Scale Transmutation
Industrial Scale Power Generation
with Energy
Industrial Scale Power Generation without Energywith Energy
Storagewithout Energy
StorageBeam Power 1‐2 MW 10‐75 MW 10‐75 MW 10‐75 MWBeam Energy 0.5‐3 GeV 1‐2 GeV 1‐2 GeV 1‐2 GeVBeam Time Structure
CW/pulsed (?) CW CW CW
Beam trips (t < 1 sec)
N/A < 25000/year <25000/year <25000/year( )Beam trips
(1 < t < 10 sec)< 2500/year < 2500/year <2500/year <2500/year
Beam trips (10 s < t < 5 min)
< 2500/year < 2500/year < 2500/year < 250/year(10 s < t < 5 min)
Beam trips (t > 5 min)
< 50/year < 50/year < 50/year < 3/year
Availability > 50% > 70% > 80% > 85%
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S. Henderson, thisworkshop
CEBAF Downtime from All Sources
SRF R l t d D tiA. Hutton, thisworkshopSRF Related Downtime workshop
CLEAN proposal
• CLEAN (a CW Linac for Efficiency and Availability iNnovation) is a proposal to demonstrate a high‐efficiency, high‐reliability superconducting linac section at Jefferson Lab to serve as a model for future SRF linacsmodel for future SRF linacs
• The goal is to improve the reliability (downtime) by a factor of five and to reduce the energy consumption by a factor of two
d hcompared to the present CEBAF sections• The outcome of this project will increase the energy efficiency
of future accelerators, reduce the carbon footprint, and makeof future accelerators, reduce the carbon footprint, and make it more environmentally acceptable to propose these large installations. A. Hutton, this
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Upper Limit SRF Accelerator EfficiencyUpper Limit SRF Accelerator Efficiency
• Toy Model
21beam beam beam beam
WPbeam beam beamcryo rf
E I E IE E IVP P
0/y f
cooling rf rf beamV R Q Q
• Ebeam and Ibeam: operating energy and current
• V, R/Q, Q0: cavity voltage, R/Q, and Quality Factor, , 0 y g , , y
• ηcooling = 0.1% (1000 W/W), significantly changeable??
(d d ti l )Thomas Jefferson National Accelerator Facility Page 15
1st International Workshop on Accelerator Driven Sub-Critical Systems and Thorium Utilization
(decades time scale)
Some NumbersSome Numbers
• R/Q = 100 Ω/cell at velocity of light (Piel’s Rule), somewhat less for lower velocities (assume 250 Ω/cavity in estimates). Difficult to change at factor of 2 level.in estimates). Difficult to change at factor of 2 level.
• Q0 now 1010 at 2 K: steady progress (about factor of 2 improvement per decade, but hopefully we’ll get better going forward). Cooling requirements decrease proportionately as Q0 increases
• η is very nearly 1 for SRF operating at its matched• ηrf-beam is very nearly 1 for SRF operating at its matched load, is 50% for normal conducting RF at “critical coupling”
• ηrf is above 50% these days with intelligent design and choices, but can never exceed 1. Not much room for improvement
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improvement
Some CW SRF CasesSome CW SRF Cases
Quantity GEMSTAR pGEMSTAR CASE I CASE II
Ibeam [mA] 10 40 10 1
V [MV] 7 5 14 10
Q0 1010 1010 2×1010 1010
η 1 1 1 1ηrf-beam 1 1 1 1ηrf 0.6 0.6 0.6 0.6
ηWP .51 .58 .51 .17
BOTE: CEBAF today 7% WP efficiency could be 25% at 1 mA close to η f at 10 mA
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1st International Workshop on Accelerator Driven Sub-Critical Systems and Thorium Utilization
BOTE: CEBAF today 7% WP efficiency, could be 25% at 1 mA, close to ηrf at 10 mA
Some conclusions from toy modelSome conclusions from toy model
• To first order, the efficiency does not depend on the operating energy, but does depend on the operating voltage choice. If efficiency were the only consideration,voltage choice. If efficiency were the only consideration, one should operate at lower cavity voltages with larger numbers of cavities
• Progress in Q0 will continue to yield benefits for overall system efficiency
• Everything else being equal one should design the linac• Everything else being equal, one should design the linacand SRF system to match the highest current possible and distribute the current to as many cores as possible. This arrangement leads to highest “wall plug” efficiency.
• High wall plug efficiency in even a single driven core seems likely with current SRF technology
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1st International Workshop on Accelerator Driven Sub-Critical Systems and Thorium Utilization
seems likely with current SRF technology
GENEPI- 1 at MASURCA: operation & results
• Key dates :
• 1996-99 : design, construction and commissioning at LPSC g g
• 2000 : installation in MASURCA
• 2001 : first neutrons, safety tests
• 2002 : first couplings in subcritical configuration on D then T
• 2003-2004 : operation for experimental program
• 2007 : end of dismantling• 2007 : end of dismantling
Data on-line reactivity monitoring, limitations of MUSE-4 y g,
& recommendations for future experiments[C.Destouches et al, NIM A 562 (2006), 601-609] M. Baylac, this
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European Collaboration (2000-2004) within FP5 under the “MUSE” acronym
European contract MUSE FIKW-CT-2000-00063
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Main issues in ADS reactor physics• Modeling/simulation code validation
• Models and codes designed mainly for critical thermal reactors
• No predictive models for fast sub-critical reactors
• Codes need for validation/performance evaluation
• Monitoring of k or reactivity ρ (safety issue)• Monitoring of keff or reactivity, ρ (safety issue)
• To guaranty a criticality margin allowing the power control of the reactor through the simple law:
safety criterium :
-5000 pcm < ρ < -3000 pcmρ(t)I(t)C(t)Pth
Need for absolute reactivity online monitoring during reactor operation(with no reference to a critical state) M. Baylac, this
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Mock-up experiments
A.Billebaud, ADS Experimental Workshop, Torino, 2010
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Design of the accelerator GENEPI-1
1. High voltage platform 5. 45° magnet 8. Thimble with 6 quadrupoles
M. Baylac, thisworkshop
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2. Duoplasmatron source
3. Accelerator
4. Quadrupole Q1
6. Quadrupole Q2
7. Quadrupole Q3
9. MASURCA assemblies
10. Target
Pictures of GENEPI-1
Special assembly with a
channel for GENEPI beam guide Thimble
GENEPI 1 at LPSCM. Baylac, this
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GENEPI-1 at LPSC workshop
Construction phase (2007-2009)
Courtesy of SCK•CEN
M. Baylac, thisk h
Avril 2009
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Commissioning at LPSC – July, August 2009
Beam profiler : characterizations
Thimble, insertion Thimble, insertion channel mock-up :
Thermal testsM Baylac this
24Alternative terminal setups
M. Baylac, thisworkshop
Beam line insertion into the core lower level
M. Baylac, thisk h
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Isochronous CyclotronsIsochronous Cyclotrons
P. McIntyre, thisk h
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P. McIntyre, thisk h
Thomas Jefferson National Accelerator Facility Page 27
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Electron Beam Drivers for ADSElectron Beam Drivers for ADS
K. Mittal, thisk h
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K. Mittal, thisk h
Thomas Jefferson National Accelerator Facility Page 29
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SummarySummary
• SRF accelerators have demonstrated ADS-level performance suitable for core drivers as regards to beam energy, peak current, and beam quality.energy, peak current, and beam quality.
• There are sound arguments that SRF systems can be designed with suitably high efficiencies for ADS drivers.
• Experiments in Europe have already started to address experimentally the accelerator-subcritical reactor interfaceinterface
• Uncertainties exist surrounding SRF accelerator realiability requirements and potential performance in the y q p pADS setting. Experiments designed to address and reduce these uncertainties are in order.Alt ti ADS d i h ld b d i ll l
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• Alternative ADS drivers should be pursued in parallel.