Radioactive Beam Proposal for iThemba LABS

Robert BarkiThemba LABS

Outline of Talk

• Need for a new accelerator

• Ideas for a RIB facility

Rf-system

Sector Magnet

Rf-system

Low Energy In

High Energy Out

Separated-Sector Cyclotron (SSC)

Most Powerful Accelerator in Southern Hemisphere

Separated-Sector Cyclotron FacilitySeparated-Sector Cyclotron Facility

0 10 20 m

beambeamswingerswinger

SSCSSC

SPC1SPC1SPC2 SPC2

Polarized ion sourcePolarized ion source

ECR ion sourceECR ion source

RadioisotopeRadioisotope production production

Neutron therapyNeutron therapy

SpectrometerSpectrometerTarget vaultsTarget vaults

electronicselectronics electronicselectronics

Proton therapyProton therapy

Multi-User Facility

•Proton Therapy: 200 MeV p•Neutron Therapy: 66 MeV p, ~ 40µA•Isotope Production: 66 MeV p, up to 350µA•Nuclear Physics: various beams

◊ Nuclear Physics◊ Nuclear PhysicsNuclear Physics

© Neutron Therapy© Neutron Therapy

© Proton Therapy©© Proton TherapyProton Therapy

© Energy Change©© Energy ChangeEnergy Change

© Isotope Production© Isotope Production

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Proton Therapy

•Paediatric tumours•Tumours close to critical structures•Brain tumours•Gastro-intestinal tumours (rectum, liver, pancreas)•Prostate tumours•Lung tumours•Recurrent tumours

Proton Therapy

Present Schedule Restricted to 2 “Fractions” / week

•Brain tumours

If schedule allowed 5 “Fractions” / week

iThemba LABSRadionuclide Distribution Network

Africa 3

Australia 2

Asia 19

Canada 2

Europe 31

USA 12

Nuclear Physics Research

• Nuclear Structure– Pairing Isomers– Pairing Vibrations– Tetrahedral Shapes– Hyperdeformation– Chirality– Giant Resonances

• Nuclear Reactions– Fusion Barrier Distributions– Incomplete Fusion– Astrophysical reactions– Production of intermediate mass fragments– Reaction Mechanisms

K600 Spectrometer

AFRODITE at iThemba LABSγ-ray spectroscopy

9 Compton Suppressed Clover detectors

8 LEPS detectors

Insufficient beamtime for

HumanResource Development

A Nuclear Future

• Cabinet approved 20-year Integrated Resource Plan

• 9.6 GW Nuclear Power

• ~ 6 ×1600MW Pressurized Water Reactors

• ~ R350 000 000 000

The Future : A New Cyclotron at iThemba LABS

•Isotope Production off SSC (uses 66 MeV p beam) (neutron therapy to be terminated?)•Free SSC for use by Physics and proton therapy only (PT to get 230 MeV machine?)•More than doubles physics beamtime•Two accelerators allow the production of radioactive beams using the ISOL method

C70 GENERAL DESCRIPTION• Diameter < 4m • Weight > 120t• Magnetic Gap: 30mm• Magnetic field: 1.55T• Extraction Radius: 1.2m• 2 exit ports

SPES SPES designdesign

• Particles: H‐ / D‐ / He2+/ HH+

• Variable Energy : 15 MeV 70 MeV

• extraction Systems: Stripper H‐ / D‐

Deflector He2+/ HH+

• Performances:750µA H‐ 70MeV Current upgrade up to 1.5mA35µA He2+ 70MeV

12 weeks

20 weeks

4 weeks

2 weeks

Nuclear Physics: Why Radioactive ion beams ?

Materials Analysis with Radioactive Beams: Hyperfine Structure

Mössbauer Spectroscopy

57Mn implanted into diamonddecays to 57Fe

Spectral components correspondto Fe atoms occupying substitutionaland interstitial sites

K. Bharuth-Ram et al

Electron Emission Channeling

Solid State Physics at ISOLDE

Lattice location of Fe in Diamond

K. Bharuth-Ram et al

59Mn (t1/2 = 4.6s) implanted into Diamond, decays to 59Fe whichβ-decays with t1/2 = 45 days

Electron emission channelingMeasurements indicate that65% of Fe atoms lie within 0.2 ÅFrom a substitutional site

HOW? - Isotope Separation Online (ISOL)

Formation of RIB “group”

•Myself•2 MSc students

•Zipho Ncobo (MCNPX calculations)•Lucky Makhathini (Laser Ionization in collaboration with University of Stellenbosch)

•Dr John Cornell on part-time basis

Floor Plan Version 19

Low-energybeamlines

Mass analyser

Beam cooler

Target / ion-source maintenance Target storage

Robot

RIB productionstations

Location for future injector

Charge breeder

RIB production Performance

OR

OR

MRCyclotron 80.00Facilities for radioisotope productionTwo vaults with four production stations and one experimental station 180.12Beam lines and power supplies 22.93Diagnostic equipment 4.03Vacuum systems 1.95Control system 1.75Radiation detection and interlocking 0.75UPS and power distribution 15.07Water cooling and airconditioning 11.50Buildings and shielding 74.29Site 0.66Contingency 50.00

Total 443.04

Phase I Costs – latest estimates

MRRIB target vaults 45.8Beam Transport(including ECR,cooler,mass separator, vacuum) 85.5Buildings & Infrastructure 20Safety & Control 50Contingency 50

TOTAL 251.3MR

+New Injector? 100

Phase 2 Costs – latest estimates (RIB production only)

Latest cost estimate

Probably can be done for: R450M Phase I (pink)

+R250M Phase II (RIBS) (yellow)+R100M for experiments (?)

Possibly Phase I will become a commercial venture: NECSA/NTP partnership ?

TASKS 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Laser Ion Source Mini Proposal

Construct Mini Laser Ion Source

LIS beam develop./low en. Beams

Total Facility Proposal

Design Process

Approval Process

Upgrade SSC

Construct New Cyclotron

Construct New Isotope Prod. Facility

24/7 SSC Physics Programme

Construction Target/Beam Transport

RIB delivery/physics

iThemba Timeline – Phased Approach

Preliminaries Phase I Phase II

While Phase II is under construction

Increased beam time for stable beam nuclear physics. Talks by:

Andy BufflerRetief NevelingJohn Carter

Which radioactive beams?

•Beams for material sciences•7Be, 22Na, 28Mg, 31Si, 38Cl, 47V, 42K, 43K,• 65Ni, 67Cu, 67Ga, 69Ge, 71As, 73Ga, 110Sn,• 111Ag, 113Ag, 117Cd, 119Sb

•6,8He Paul Papka•Proton Rich ? Nico Orce•Neutron Rich: Fission Target

Proton –rich ⇒different target per beamNeutron-rich ⇒ one 238U target; 100 beams

FISSION URANIUM

Reaching the neutron rich: FISSION URANIUM

SPES target

direct fission at SPES

p-induced fission vs ν-induced fission

HRIHRIBF Calculations

two-step fission vs one-step fission

HRIHRIBF Calculations

best neutron converters

Deuterons on a Carbon converter at GANIL

Can we do better at iThemba?BeO converter (safe, good thermal conductivity)

H Calculations by Deon Steyn

Temp vs time, 2000 rpm wheelTemperature distribution in rotating BeO target 28kW (400µA 70 MeV)

Headache: diffusion & effusion

ionization to 1+ laser-ionization

•Highly Selective•Highly efficient

•~10%•Essential for fission targets

Two-step laser ionization of Sr being demonstrated atStellenbosch University– MSc project of Lucky Makhathini

Charge breeding with 14 GHz ECR source

Limit due to chargebreeding time10ms/Q

Limit due to target diffusion/effusionTime ~ 1.2s

Neutron rich intensities ultimately limited by half lives and diffusion/effusion times

Use IGISOL (gas transport) ?

RIB Production 70 MeV protons 350µA

Sn isotopes

120 122 124 126 128 130 132 134 136 138

Acce

lera

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nsity

pps

1e+0

1e+1

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1e+3

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SPES baseline scaled up 1.4sGas 165 gm U 0.2sSPIRALII (d beam) 5 kg 3.2sBe Conv or SPIRAL II500gm U 3.2sORNL Direct Calc 1.4s

Stable

0.53s

0.25s

1.1s

40s

Accelerated Beam Intensities

0.19s

Neutron-rich post-accelerated yields from 238U(p,f) at 180 µA 70 MeV p (5 x 1.1 cm 6.6g/cm2 UC target at HRIBF).

Refractory elementsIGISOL?

International Comparison ISOL Facilities

FACILITY 132Sn intensity pps(accelerated beam on target)

SPES (Italy) 108

SPIRAL II (France) 109

HRIBF (USA) 108 ?

HIE ISOLDE (CERN) 108

ITHEMBA LABS 108 ?

BRIF (China) 107

KORIA (Korea) 109

Other Beams

Cross – Sections typically more than an order of magnitude higher than for a particular fission fragment.

Implies RIB intensities of up to 1 pnA possible

Separated-Sector Cyclotron FacilitySeparated-Sector Cyclotron Facility

0 10 20 m

beambeamswingerswinger

SSCSSC

SPC1SPC1SPC2 SPC2

Polarized ion sourcePolarized ion source

ECR ion sourceECR ion source

RadioisotopeRadioisotope production production

Neutron therapyNeutron therapy

SpectrometerSpectrometerTarget vaultsTarget vaults

electronicselectronics electronicselectronics

Proton therapyProton therapy

Possible location of RIB test ion-source

RIB ion-source Test Station + β-decay + Materials

Demonstrator with “Unaccelerated” RIBs

The Parallel discussion will divide into Materials and Nuclear groupswith the exception of a discussion around the RIB demonstrator.

Suggested topics for the Nuclear session are:

Light n-rich RIBsAn active TargetCoulex and Proton-rich beamsLarge Acceptance Spectrometer/n-rich beams Desired Beams

Suggested topics for the Materials session are:

Mössbauer SpectroscopyElectron Emission ChannelingDesired Beams

Parallel Discussion

Thank You