accelerator summary - virginia techkimballton/gem-star/workshop/presentations/kra… · 1st...

Accelerator SummaryAccelerator Summary

Geoffrey KrafftJefferson Laboratory

Old Dominion University

Thomas Jefferson National Accelerator Facility

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



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

workshop

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



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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


1st International Workshop on Accelerator Driven Sub-Critical Systems and Thorium Utilization7

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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

9

LANL LEDA RFQCourtesy D. Schrage

SNS SC cavitiesCourtesy J. GalambosP. Ostroumov, this

workshop

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

10

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

k h



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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%

12

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

k hworkshop

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


(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



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



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



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

workshop

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European Collaboration (2000-2004) within FP5 under the “MUSE” acronym

European contract MUSE FIKW-CT-2000-00063

workshop

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

k h

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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

k h

22

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



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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



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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



• Alternative ADS drivers should be pursued in parallel.

accelerator summary - virginia techkimballton/gem-star/workshop/presentations/kra… · 1st...

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