Accelerator Development SM April 2015

Titan Pulse Sciences Group Jan. 07 2005

APPLICATIONS OF ACCLERATORS AND PULSED POWER SYSTEMS FOR COMMERCIAL AND

GOVERNMENT APPLICATIONS

Stephan T. Melnychuk, Ph. D.


Background

• Northrop Grumman Corporation 1991-1998– High power ion linacs for government applications– Electron linacs and FEL’s– RF cavities and magnets for research linacs (RHIC-BNL)– High power RF systems– X-ray sources – (lithography)

• Advanced Energy Systems 1998-2000– Small business ~ 20 employees spun off from NGC– Commercialization of Accelerator and plasma technologies– Engineering services– New Business initiatives

» Medical imaging, Cancer therapy, Security, Support services for National Labs.• Cymer Inc. 2000-2004

– Light sources for photolithography» Excimer lasers» Plasma pinches for EUV generation» Laser produced plasmas for EUV generation» New Business initiatives-Opportunity scanning (LTPS-flat panel displays)


History

• Organized within Grumman (1975) for Tokamak Fusion Test Reactor project at Princeton

• Strategic Defense Initiative involvement in Accelerator Technology begins in 1984

• Relativistic Heavy Ion Collider superconducting magnet production begins in 1992

• Contraband Detection System & Laser Electron Accelerator Facility are recent accelerator applications

• Spun off by Northrop Grumman in September 1998

• Over $400M in Sales since 1975


Experience

• Experience base in all phases of accelerator technology (R&D, modeling, design, manufacturing, commissioning & operations)

• Experience working with national laboratory culture (LANL, BNL, LBL, ORNL, ANL, LLNL and TRIUMF)

• Experience working programs over international borders (IFMIF, CDS, IPHI, CWDD)

RHIC

CDS


Product Areas Ion Accelerators

Positive & negative ion sourcesAccelerating structuresTurnkey beamlines

Electron AcceleratorsHigh-brightness electron gunsStanding & traveling-wave structuresRoom-temperature & superconducting cavitiesTurnkey beamlines

Special ComponentsBeam diagnosticsSuperconducting magnetsWigglers & undulatorsLithography light sources

Engineering & Physics ServicesIntegrated engineering design and analysisSystems engineering, costing & RAMIEngineering & physics computational analysis

PRODUCTS& SERVICES

CCLThermalAnalysis

Radio Frequency Quadrupole


Customers & Markets

National Laboratory R&DLos Alamos, Sandia, Oak Ridge, Lawrence Berkeley & Brookhaven National Laboratories Thomas Jefferson National Accelerator Facility Princeton Plasma Physics Laboratory

University R&DColumbia, Princeton, Maryland, Vanderbilt, Duke

US GovernmentDoD, DoE, FAA, NIH

InternationalFrance, Japan, Austria, Germany, Belgium

CommercialContraband DetectionSemiconductor ManufacturingMedicalMaterial Processing & Sterilization

CUSTOMER SATISFACTION

APT CCDTL


Core Competency Project Management

Integrated Engineering Design & AnalysisMechanical, Thermal, Cryogenic, VacuumTooling, Producibility & Manufacturing

Systems EngineeringSystems Modeling, Analysis & TradesCostingRAMI

Physics & ComputationPhysics Design & AnalysisComputational Modeling

TechnologiesAccelerator TechnologyFusion & Plasma SciencesNuclear Sciences

INTEGRATEDSOLUTIONS

00.5

11.5

22.5

33.5

4

0 2000 4000 6000 8000Operating Time [Hr]

Triti

um O

utpu

t [kg

]

6257 Hr

Target/Blanket

12% Linac75%Balance Of

Plant13%

Injector 5%RFQ 1%

100 M eVCCDTL &CCL 27%

M ed. β SCL 8%HI β SCL 26%

HEBT 20%

RFQ, CCDTL,CCL RF 2%

SCL RF7%

Cryoplant1%

20 M eV CCDTL 3%

Corrective M aintenance

17%

Required Production 71%

Scheduled M aintenance

12%

0

200

400600800

10001200

AnnualShutdown

BiweeklyShutdown

Sche

dule

d M

aint

[Hr]

Total = 1008 Hr

System UnavailabilityScheduled Maintainance

Required ProductionLinac Unavailability

x 9 . 2 30 mm 9 . 7 40 mr ad

x 6 . 160 Deg 386. 3 10 KeV

x 2 . 0 00 mm 25. 0 00 mr ad

x 0 . 450 Deg 2000. 0 00 KeV

N P1= 1 NP2= 4 1 36. 50 mm ( Hor i z ont a l ) 1 2. 5 Deg. ( Longi t u d i na l )

36. 50 mm ( Ver t i c a l ) Lengt h= 6 068. 62mm

1

SOL

2

3

4

5

6

C

7

C

8

C

9

C

1 0

11

Q

1 2

1 3

Q

14

15

Q

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18

19

E

20

B

21

E

22

23

Q

24

25

26

Q

27

28

E

29

B

30

E

31

32

33

Q

34

35

Q

36

37

Q

38

39

40

41

H A=- 6 . 490 B = 6. 220 V A=- 6 . 490 B = 6. 220

Z A= 6 . 650 B =0. 1073

BEAM AT NEL1= 1H A=0. 2704 B =0. 5831 V A= 5 . 173 B =0. 5956

Z A= 1 . 367 B =0. 5493E- 0 3

BEAM AT NEL2= 41 I = 4134. 0 mAW= 7 . 79 46 16. 42 59 MeV

FREQ=1300. 00 MHz WL= 230. 61 mmEM I TI = 13. 6 90 13. 69 0 354. 1 4EM I TO= 6 . 8 63 6 . 70 4 356. 3 8

N 1= 1 N2 = 41

MATCHI NG TYPE = 11DESI R ED MODI FI ED BEAM MA TRI X S11 = 2 . 000 000 S33 = 2 . 000 000

MATCH VARI ABLE S ( NC=2)MPP MPE VA LUE

1 3 5 - 1 . 13 540 1 3 7 1 . 12 390

P o w e r T r a c eCODE: TRA CE3D v 61 bDA TE: 03- 17- 1998

TI ME: 18: 56: 38


Experience With Large Programs

• CWDD ($75M contract for USASDC) - 1988 to 1993

– International team (AES, Culham, LANL, Marconi)

– Physics, design, fabrication,integration & test


RFQ Development

RFQ Unit #1 Integrated at Los Alamos

for Space Flight Expermient

(1989)

RFQ Unit #2 Integrated in

AES ResearchBeamline

(1990 - 1999)


Cryogenic CW RFQ Development

(a)

(e)

(c)

(d)

(b)

(a) Test pieces for electroformed cooling channels ultimately proof tested to 10,500 psi; (b) Full RFQ cavity quadrant readyto electroform cooling channels; (c) Four RFQ quadrants assembled and aligned prior to final electroform joining process;(d) Finished 1 meter RFQ segment; (e) Final assembled four meter RFQ accelerator with coolant distribution system

AES performed complete Physics, Engineering, Fabrication, and Integration

RFQ in Cryostat VesselIntegrated in Beamline Vault

• Duty Factor - 100% (CW) • Particle - D-

• Current - 80 mA• Coolant - Supercritical Neon• Operating Temperature - 35K• RFQ Energy - 2 MeV


2 MW CW RF System

Installed & Tested at Argonne National Laboratory


CIRFEL RF Power

20 MW pulsed system at 2856 MHz

10 Hz repetition rate

AES performed design, fabrication, integration and test


Thermionic and Photocathode Electron Guns

AES produces high-brightness S- & L-band photocathode & thermionic electron sources

AES has initiated R&D projects for enhanced high-performance DC/SRF guns & integral SRF electron guns

S-BandElectron Gun

CIRFEL

LEAF


Laser Electron Accelerator Facility (LEAF)

• Electron Accelerator and Beamline

• Delivered to Brookhaven National Laboratory

• Used for Chemistry Research

• Built to Customer Specifications• Installed & Commissioned at

Customers Facility


Superconducting X-Ray Lithography Source (SXLS)

• Industrial Partner to Brookhaven National Laboratory

• Compact Synchrotron Design & Commissioning

• X-ray Beamline Design


MXIS


SCRF


Linac and Ion Source Development


1.76 MeV RF Proton Linac -NGC


Applications I

• Development of pulsed high brightness H- ion sources for SDI• Development of CW RF driven H+ ion sources for APT, ATW, SNS• Beam transport

– Space charge compensation– Phase space matching to accelerating structures

• Diagnostics– Toroids,Capacitive probes,Wire harp profile monitors,Emittance diagnostics

• Control Systems– PC based: DAQ, A/D converters

• RF Linacs– High brightness H- beams for Neutral Particle Beams– High current CW beams for Tritium Production and Transmutation– Proton Therapy/Medical systems

• High current DC Electrostatic Accelerators for Explosives Detection and Medical Applications (CDS)

• Materials Testing supporting CDS


Linac Features

• Ion source: H+/-, 100 mA, 2 MHz Internal Antenna, Multicusp confinement.

• Gas compensated magnetic transport (Dual solenoids) • RFQ: 425 MHz, 1.013 MeV output,- designed for 0.1%-

operated at 0.7% with added cooling, 67 kW cavity power, -34 deg synch phase.

• Transverse and Longitudinal Matching cavity• 8 cell DTL-1.76 MeV• EMQ HEBT• Autostart and auto optimization of transported current• Diagnostics: Electrostatic emittance scanners, beam

toroids, HARPS, Pin Probes, Stripline capacitive probes for position, TOF and synch phase


Accelerator Diagnostics

• Electrostatic sweep plate emittance scanners– 30 keV 1% DF beams (10 Hz, 1 msec)– 1.76 MeV 0.7 % DF beams– CW high current (100 mA) 70 keV

• Moveable magnetic dipole mass spectrometers• Profile Harps• Pin Probes• Capacitive probes

– centroid position– synch. Phase– TOF

• Faraday cups/High power beam dumps• Radiometric profile monitors


Pulsed Beamline H+ current

• Input current limited by losses in transport system.

• RFQ transmission limited by input emittance and divergence.

• Remote beam tuning demonstrated with pin probe diagnostics.

t [micro sec]0 100 200 300 400 500 600 700 800 900 1000

BEAM

CU

RR

ENT

[mA

]

0

10

20

30

40

50

60

70

Ion source

RFQ In

RFQ Out

RF POWER [kW]0.0 5.0 10.0 15.0 20.0

BEAM

CU

RR

ENT

[mA

]

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0


Pulsed Source Mass Scans

RF POWER [kW]9.0 10.0 11.0 12.0 13.0 14.0 15.0

MAS

S FR

AC

TIO

N

0.01

0.1

1

H+

H2+

H3+

Dependence of proton fraction on RF power, dipole filter field, and configuration of extraction region measured.


MS and DTL

Ion Source Output [mA]0 10 20 30 40 50 60 70 80

Tran

spor

ted

Cur

rent

[mA

]

0

10

20

30

40

RM

S E

mitt

ance

[pi m

m m

rad]

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

Transmitted Current vs Ion Source Current and Emittance

MS Relative Phase [deg]-200 -100 0 100 200

Hor

izon

tal r

ms

emitt

ance

[pi m

m m

rad]

0.065

0.070

0.075

0.080

0.085

0.090

0.095

DTL

Tra

nsm

issi

on

0.0

0.1

0.2

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0.6

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1.0

1.1

1.2

DTL transmission and MS output emittancevs. MS phase.


CW Ion Source

• APPLICATIONS:– Accelerator Production of Tritium– Transmutation of Waste– Neutron Generators (SNS Linac)

• GOALS:– Demonstrate technical proficiency to DOE– Demonstrate 160 hrs of continuous beam operation at 100 mA H+ current– Characterize beam phase space and mass fraction

• EXPERIMENTS:– Generate high proton currents– RF matching of Ion Source to 2 MHz generators (35 kW triode, 15 kW pentode)– Optimize ion species for highest H+ fraction– Optimize beam optics-demonstrate low divergence and emittance– Achieve long term operation


CW TEST STAND (II)

• 10 cm RF driven multicusp ion source

• 35 kW amplifier and matching section

• CW emittance scanner• Mass spectrometer• Faraday cup


ISOLATION AND MATCHING TRANSFORMER

• Isolated to 46 kV from primary to secondary• Variable primary taps (N:1) for impedance

matching• LC network on secondary : CF = 2.000 MHz• Designed for 35 kW CW operation

antenna


(f-f0)/f 0 [x 1000]

-10 -8 -6 -4 -2 0 2 4 6

Phas

e [d

eg]

-20-15-10

-505

101520

-8-

-8-

-8- -8-

-8-

-8-

-8--8-

-8-

-10--10--10--10--10--10--10-

-10-

14-14-

14-14- 14-

14-14-

14-14-

-26-

-26--26--26-

-26--26-

-26--26--26-

-45-

-45--45--45-

-45--45--45-

-45--45-

D D D D D D D D D D D D D DD

DD D

D

Z [O

hm]

30

40

50

60

70

80

90

-8--8-

-8- -8- -8- -8- -8- -8- -8--10--10--10--10--10--10--10--10-

14- 14- 14-14- 14- 14- 14- 14- 14-

-26--26-

-26--26--26--26--26--26--26-

-45--45--45-

-45--45--45--45--45--45-

D D D D D D D D D D D D D D D D D D D

INPUT IMPEDANCE MEASUREMENTS

• Measurements taken between 3.0 and 4.5 kW at constant drive amplitude set at amplifier

• I0, V0, and phase are measured at the transformer

• |Z| = V0/ I0 ,and phase depend on frequency and pressure

• Z(sec) = Z(primary)/N2

– Zsec(H2) = 1.0 Ohm– Zsec(D2) = 1.6 Ohm

» can optimize D2 match on 5:1 or 6:1 taps

f0 = 2.018 MHz 7:1 tap ratio

H2

H2

D2

D2


REFLECTION COEFFICIENT (I)

PF, and PR are measured with crystal detector at the amplifier

PNET = PF- PR = 1/2 I0 V0 cos (phase)RRAMP = PR/PF

RRXFMR = [(Z0-R)2 + X2]/[(Z0+R)2 + X2]Z0= 50; R = |Z| cos(ph); X = |Z| sin(ph)

f0 = 2.018 MHz 7:1 tap ratio

[f - f 0]/f 0 [x 10 3]

-10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0

Ref

lect

ion

coef

ficie

nt

10-5

10-4

10-3

10-2

10-1

-8-

-8-

-8--8-

-8-

-8-

-8--8-

-8-

-10-

-10-

-10--10-

-10--10--10-

-10-14-

14-14- 14- 14- 14-

14-

14- 14--26-

-26--26-

-26--26-

-26--26--26--26-

-45-

-45--45--45--45--45-

-45--45--45-

D DDDDDDDDDDDDDD DDDD

D2

H2

PRESSURE [mT]

0 5 10 15 20 25 30 35 40 45 50

RE

FLE

CTI

ON

CO

EFF

ICIE

NT

10-5

10-4

10-3

10-2

10-1(Z0-Re(Z))2 + Im(Z)2/(Z0+Re(Z))2 + Im(Z)2

R/F

• Global minimum at 10 mT

• Good agreement between measurement at amplifier and transformer.

• For optimum match at low pressure with H2

gas we should operate on the 8:1 tap ratio


CONCLUSIONS

• Demonstrated excellent RF matching over broad operating range.

• Proton fraction is limited by RF power due to antenna failures. Coating development required. (~ 45% H+ at 3.5 kW)

• Continuous operation has been demonstrated for 260 hours.

• Extraction voltage must be upgraded to improve high current transport.


High Current Tandem Accelerator for Contraband Detection and Medical Applications

S. MelnychukE. Kamykowski, J. Rathke, J. Ditta, B. Abel, J. Sredniawski

Advanced Energy Systems, Inc.

B. Milton, R. RueggA. Fong, P. Gardner, I. Tsui, M. Barnes, D. Bishop, D. Dale, B.

Roberts, G. Cojocaru, L. Graham, H. Hui, J. Kaefer, R. Watt, J. Young

TRIUMF


CDS Overview

How CDS Works *

An accelerator is used to produceprotons at an energy of 1.76 MeV such that gamma rays are generatedfrom impingement on a thin 13C target.The emitted gamma rays passthrough a volume of interest and areabsorbed so that images of nitrogendensity and total density are developedfrom the variation in gamma detectioncounts. Fluorescence or scatteredgammas resonant with nitrogen arealso produced 5% of the time there isa resonant reaction with nitrogen.

Proton Accelerator

ContainerHandling

Proton Beam

Primary GammaRays

Primary Detectors

Target

SecondaryGamma Rays

SecondaryDetectors

* Patents by Scientific Innovations


Advantages of GRA and Selected Approach

• Gamma resonance absorption (GRA)- Nuclear reactions are well known- Previous experience with nitrogen resonance- Offers potential of multi-element detection

• Position sensitive detectors- Separates resonant from non-resonant gammas- Total and elemental density simultaneously

• Tomographic imaging (3D)- Successfully used in medical technology (PET)- Will find objects hidden behind other objects

• Element specific (N,Ca,P, Cl)• Radiographic imaging capability• Spatial density distribution of elements• 100 x lower radiation dose delivered to patient• Potential for greater precision and accuracy

ANFO

Region for HE

Region for drugs

2.01.51.00.50.00.0

0.2

0.4

0.6

0.8

1.0

1.2ExplosivesDrugsCommon

Total Density (g/cc)

Nitr

ogen

Den

sity

(g/c

c)

Advantages for WBC studies compared to neutron techniques


Resonant Gamma Production Geometry

Patient

Resonant Gamma Fan

Proton Beam

Beam Production Target

Detector Array

Element P Energy (MeV) Target Matl. γ Energy (MeV) Res. Angle (deg)N 1.75 13C 9.17 80.7Cl 1.89 34S 8.21 82.0


Potential Applications and Required Resources

S. MelnychukAdvanced Energy Systems, Inc.


Potential Applications

Force Protection (DoD)• Military Bases• Counter-terrorism• Explosives Detection in Vehicles

Aviation Security (DoT)• FAA• Explosives Detection in Cargo

CDS POP Technology• World’s Highest Output

Electrostatic Accelerator• High Power Proton Target

US Customs• Border Control• Seaports• Explosives / Drug Detection

in Large Containers

Warhead/Rocket QC (DoD)• Crack & Void Detection• Mixture Quality• 24% Rejection / Shelf Life

Medical Research• Boron Neutron Capture Therapy• Whole Body Composition

Environmental Cleanup (DoD)• Unexploded Ordnance Detection• Mine Field Clearance


FAA Cargo Inspection

CDS Accelerator LD-3Container

Detector Array

ContainerMotion

Gamma Fan Beam

Need: Screening of LD-3 sized containers for 450 g sized HE threats (incl. thin sheet)Performance: 90% detection probability in 10 minutes (complete container screening)Requirements:

• Tandem accelerator @ 10 mA DC (next generation unit)• 13C Target (developed)• High resolution detectors (needs cost reduction development)• Tomography (existing)

Equipment Cost Goal: $2.25M

Next generation tandem based beamproduction module


Large Container Inspection-I

Need: Detection of 100 to 500 lb. concealed bulk explosivesForce Protection - Screening of incoming vehicles and containersUS Customs - Screening of outgoing shipping containers

Performance: � 90% detection probability (See next VG)Requirements:• High Current CW RF accelerator 10 to 50 mA (SDI technology)• 13C Target (development to higher current)• Low resolution/low cost detectors (off the shelf)• Robust for field deployment (proven for SDI)

Equipment Cost Goal: $4 to 6M

Demonstrator Device

AES Built 80 mA CWDD


Large Container Inspection-II

• Force Protection Mission– Scan slice (5 cm) through 8 ft wide sand truck– Slice discrimination in 30 seconds with 50 mA accelerator

• Customs Mission– Intermediate density packing (� 1 g/cc)– Complete container inspection times on the order of 10 minutes with

10 mA accelerator


Additional Force Protection Mission

Need: Screening of mailbags for 450 g sized HE threats (incl.. thin sheet)Performance: Throughput of 400 to 1600 bags/hr with 90% detection probabilityRequirements:

• Tandem accelerator @ 3 to 10 mA DC (next generation unit)• 13C Target (developed)• High resolution detectors (needs cost reduction development)• Tomography (existing)

Equipment Cost Goal: $1.75 to 3.25 M

Accelerator

Multiple Detection Stations Driven by a Single Tandem Accelerator

400 bags/hr each


Warhead / Rocket QC

Need: Screening for mixture non-conformities and/or aging (24% rejection)Performance: Voxel nitrogen density ratios in the 1/2%range for 16 inch steel cased shell @ 10 min/sliceRequirements:

• Tandem accelerator @ � 3 mA DC (present unit)• 13C Target (developed)• High resolution detectors (cost of present is acceptable)• Tomography (existing)

Equipment Cost Goal: $1.75M

Warhead or Rocket Motor Casing

Gamma Rays

Proton Accelerator

ImagingDetectors

γ Rays forslice imaging


Environmental Cleanup

Need: Location of UXO and Unexploded Land MinesPerformance: 3 seconds for S/N better than 3 for 1 lb. steel cased mine in 2 inches of sandRequirements:• RF accelerator @ 100 mA 1% pulsed duty (existing technology)• 13C Target (developed)• Simple low cost large capture area scintillators (off the shelf)• Robust/mobile for field deployment (proven for SDI)

Equipment Cost Goal: $2M

Gamma raysDetectors

Accelerator & Proton Target

UXO

Earth

AES built pulsed beamline - 1991


Medical Research

Proton Accelerator

Neutron Generator

Patient TreatmentPosition

Note: Dimensions in centimeters

Need: Source of neutrons for Boron Neutron Capture TherapySource of resonant gammas for Whole Body Composition (N, Ca, Cl)

Requirements:• Tandem accelerator @ � 3 mA DC with energy of 1.75 to 2.3 MeV (upgrades to existing machine)• 7Li Target for BNCT and 39K, 34S Targets for WBC (development required)

• Equipment Cost Goal: $1.75M


Summary

• GRA technology has potential for broad use– FAA– Force Protection– US Customs– Warhead / Rocket QC– Environmental Cleanup (mines & UXO)– Medical (BNCT, WBC)

• Although there are real needs, there has not been sufficient exploitation of this technology to date

– Primarily due to lack of financial commitment, not technology


GRA System Requirements

Parameter Specification AchievedValue Value

Proton Current (mA) 10 2.2Proton Energy (MeV) 1.76 1.84Proton E Spread (1σ keV) 6 5.6Resonant Angle (+/-deg) 0.5* 1.5Detector Resolution (mm) 5 5

* Note: best measured data from other sources is +/- 0.75


Key Technologies

• Electrostatic tandem accelerator– Smaller, cheaper and more efficient than rf accelerators– Compact high voltage power supply

• Practical size of CDS (compact assembly)• High output >> high proton current >> inspection time

– High current stripper- Water vapor recirculated with turbo pump

• Proton beam target– Long life in a high heat flux environment– Enables high proton current which gives fast inspection time

• High efficiency fine resolution detectors– Detection of thin sheet explosive– Fast inspection time


Beam Production Subsystem

Tandem accelerator

Ion injector

Gamma production target

High energybeam transport

Demonstrate:• High current CW proton

accelerator• Sorting of resonant &

non-resonant gamma rays• 3D imaging for N• High spatial resolution


Target, Carousel and Detectors

Rotatable table

7 BGO Detectors

Gamma productiontarget

Detector Detail


Tandem Accelerator


Carbon Targets


Target Development Summary

• Generic target requires a thin film of C13 deposited on a high Z proton stopping material, and a structural substrate

• To make a suitable target we need to understand and optimize all of the target interfaces

• Our research program addressed the choice and fabrication of the high Z material and the fabrication of thin C films by appropriate deposition techniques

• Conventional target failures observed under high beam fluences and flux densities.


Conventional Proton BeamTarget Design

E - b e a m D e p o s i t e d 1 3C

E l e c t r o d e p o s i t e d G o l

C u , B e , C u a l l o y s

Proton Beam (1.75MeV)

(1 µm)

γ ( 9.17MeV)


Experimental Test Plan

• Target testing was conducted with the NGC 1.76 MeV pulsed rf beamline.

• Target samples: 2” dia., .125” thick Cu or Be coupons with various coatings

• Experiments were conducted on the individual interfaces in question to decouple the C thin film effects from the high Z material deterioration effects

• Nominal test conditions:– Pulse length = 500 micro sec (square pulse)– Pulse repetition frequency = 10 Hz– Average proton beam current per pulse = 10 mA– Beam spot : circular with Gaussian distribution: 3*sigma = 6.5mm or

elliptical with the same effective area at 3*sigma beam fraction– Test duration = 10 - 12 hours


Target Development Summary

CarbonElectrodeposited GoldCu, Ag, Be, Cu alloys

CarbonW

Thick (C) graphite substrate

Hf or W interlayerElectrodeposited Gold

Be

Carbon

CarbonBrazed Ta foil

Cu

Carbon

Thick W substrate


Tungsten plate (1 mm thick)/Cu substrate


Magnetron Sputtered:Evaporated C/Brazed Ta/Cu Substrate

Targets after proton beam exposure at 10 mA for 12 hrs.Average dose: 1.5E19 ion/cm^2. Peak dose 3-4 times larger.

Electron beam evaporated C Sputtered C


Proposed New Proton Beam Target Design

Replace High Z Gold Layer with Refractory Metal (Ta)Advantages:

Greater Hydrogen Solubility / DiffusivityForm Carbides - improved C13 film adhesionLower CTELess Expensive (brazed foil)

Deposit 13C Layer by Magnetron SputteringAdvantages:

Improved Film AdhesionLow Substrate TemperatureUniform Deposition RateAbility to Coat Large Areas


Gamma Energy [MeV]

0 1 2 3 4 5 6 7 8 9 10

Cou

nts

0

50

100

150

200

250

Target Contamination Issues

Upper gamma spectrum shows fluorine contamination in the 5 to 6 MeV region from Fomblin vacuum pump oil on a sputtered Carbon 12 sample

Lower spectrum shows a clean 0.25 micron thick evaporated Carbon 13 sample with the characteristic 9.17 MeV gamma rays


Full Scale CDS Target Disk Design

4.5” Conflat Flange

OFE Cu Hub

14” dia OFECu Back Plate

OFE CuFace Plate

CommerciallyPure Ta Wedges

(24)

Water Channel

Mass BalancePocket

SST Alignment Pin (2)

Target Fabricated by magnetron sputtering using a 1” diameter; 0.125” thick custom carbon 13 sputter target.

Brazed Ta foil ring/wedges with 13C coating


Conclusions

• Carbon 12 and 13 targets were fabricated by electron beam deposition and magnetron sputtering. These targets were tested at CDS relevant current densities and average power densities and survived without damage.

• Target purity issues were resolved by use of non fluorine containing vacuum pump oils.

• New target design allows optimal high current operation of CDS unit. At this power level interrogated items can be inspected more rapidly increasing overall system throughput. The faster the inspection throughput of the unit the more commercially viable the technology will be with competing detection systems.


Production of 9.17 MeV Gamma Rays

Energy of proton confirmed to be at 1.76 MeV by observation of 9.17 MeV γ-rays measured with NaI-based spectroscopy system

Measured rate of production of resonant 9.17 MeV γ-rays in agreement with theoretical predictions (2700 γ/µa-sr-sec)


Proton Energy [keV]1730 1740 1750 1760 1770

9.17

MeV

Gam

ma

Cou

nts

0.0

0.2

0.4

0.6

0.8

1.0

Measured yield curve on CDS accelerator showing full utilization of the beam with an rms energy spread of approximately 6 keV

Measured yield curve from the Van de Graff accelerator showing the resonant peak yield at 1.746 MeV with a target thickness 4 keV or 0.25 microns

Proton Beam Energy Spread


Proton Beam Energy Spread

• Results– Thick target yield curve data for proton energies between 1.726 and

1.794 MeV derived from NaI detector gamma ray spectra with energy window between 7.8 and 9.5 MeV to include full energy as well as escape peaks

– Analysis of yield curve data indicates FWHM = 13.3 keV or a one sigma value of σ = 5.6 keV which is within the energy spread requirement for the tandem accelerator

– Analysis indicates that the water vapor stripper in the tandem terminal does not contribute significantly to the overall energy spread of the beam


Position Sensitive Detection

ProtonBeam

Target

Non Resonant

N SegmentedBGO Detectors

Cl

Determines densities of 5 mm3 voxelsWill find thin sheets and concealed items


First 2D Projection Image

Projection ImageWith CDS HighResolution Detectors

Orientation ofLead Brick

Hole in Brick

High resolution (5 mm) of the CDS detectors is clearly evident


3-D Imaging Test (Total Density)

• Objective– Demonstrate capability of gamma ray

resonance absorption technology to provide 3-D imaging data and information

– Test image reconstruction software for future tomographic 3-D analysis

• Results– Image data were obtained using a

melamine wedge phantom (30 cm long, 10 cm wide, taper to 3 cm) at 30 equally spaced angular positions and at 8 vertical positions with 1 cm step height per slice


Map Resonant Gamma Fan

Target

Non Resonant

SegmentedDetector

NCl

Resonant

• Objective– Determine spatial location of resonant gamma fan with respect to target and

detector using position sensitive BGO detector array.– Confirm the CDS system can distinguish a nitrogen-rich object from a non-

nitrogenous object with similar line density.

Resonant gamma band from detector view.

Position separation of resonant gammas

Accelerator Development SM April 2015

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