Nuclear Structure, Safety,

and ApplicationsI. Usman, J. Carter, E. Sideras-Haddad, G.R.J. Cooper,

L. Donaldson, M. Latif, N. Botha, R. Neveling, F. D. Smit, P. von Neumann-Cosel, O. Zamonsky, R. Prinsloo, L. Jurbandam,

J. Larkin, I. Petr, D. Vermillion, H. Hall, K. Tsolo and S. Mokoatsi

Nuclear Structure

• K600 Magnetic Spectrometer of iThemba LABS

• Giant Resonances: • High energy-resolution experiments on giant

resonances: => ISGMR, IVGDR, ISGQR

• Using Light-ion inelastic scattering at finite angles and zero-degree => (p,p’) and (,’)

• Extraction of energy scales => Wavelet Analysis• Comparison with theoretical calculations • Extraction of Spin and Parity dependent Level

Densities• Experiments on Cluster states: Reaction channels => Hoyle States in 12C

=> (p,t) and (p,3He)

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

electron icselectron ics electron icselectron ics

Proton therapyProton therapy

iThemba LABS Cyclotron Facility

K600 magnetic spectrometer at 0o

Focal plane detectors:2 multiwire drift chambers (U and X wireplanes)2 plastic scintillators

beam of 1 nA: 6x109 particles/sscattered particles: 103 particles/s

(p,p') setup: B(D1)/B(D2)=1.5 (p,t) setup: B(D1)/B(D2) = 1

K600 Magnetic Spectrometer

Best resolution = 25 keV @ 200 MeV on Au targetBest resolution = 9 keV @ 66 MeV on Pb targetLargest angle so far = 87o

Smallest angle = 2o with internal beamstop

2 VDC: high accuracy horizontal position determination in focal plane

1 HDC: high accuracy vertical position determination

2 plastic scintillators (BC-408) acting as trigger detectors for particle identification

Scattering chamber

Dipole magnet 1

Plastic scintillators

Drift Chambers

Contact person: neveling@tlabs.ac.za

MonopoleDL = 0

DipoleDL = 1

QuadrupoleDL = 2

DT = 0DS = 0

DT = 1DS = 0

Isoscalar Isovector

Giant Resonances: Macroscopic Picture

Courtesy of P. Adrich

+ +

Direct decay Pre-equilibrium andstatistical decay

Escapewidth

Spreadingwidth

Landaudamping

Contribution to the width of giant resonances

Resonancewidth

Methods of Extraction of Energy Scales

Wavelet Analysis

Characteristic energy scales

Power spectrum

ISGQR: (p,p’) applying dispersion-matching techniques

IVGDR (p,p’) and ISGMR (,’)

Targets:

Scattering angles: Maximum of ∆L = 1, zero-degree measurements

∆E = 35 - 50 keV

Recent high energy-resolution giant resonance experiments at 200 MeV

Targets: 58Ni, 89Y, 90Zr,120Sn,166Er, 208Pb

12C, 27Al, 28Si, 40Ca ∆E = 25 - 35 keV

142,144,146,148,150Nd

27Al, 40Ca, 42Ca, 44Ca, 48Ca, 56Fe, 58Ni, 208Pb

Scattering angles:Maximum of ΔL = 2, finite scattering angles

ΔE = 35 - 40 keV

142,144,146,148,150Nd ∆E = 25 - 35 keV

What is the origin of scales in 40Ca?

The RPA model accounts for Landau damping, which plays an important role in the case of 40Ca (but not in heavier nuclei).

To understand the origin and physical nature of different scales, comparison of experimental results with model calculations is important.

Such models include - Quasi-particle Phonon Model (QPM)- Random Phase Approximation (RPA) - Second-RPA (SRPA)- Extended Time Dependent Hartree-Fock (ETDHF).

Comparison with theoretical calculations

Nuclear Safety• Protecting People and the Environment• Radioactive Waste Management• Risk Assessment• Responding to Radiological

Emergencies• Cleaning up Radioactive Site• Naturally-Occurring Radioactive

Materials in Soil, Air and Water• Smoke Detectors• Food and Mail Irradiation

Nuclear Safety Honours Projects• Miss Linina JurbandamEvaluation of the Fission Energy Deposition at the SAFARI-I Reactor using MCNP5

• Mr Sekao Mokoatsi Environmental radiological impact associated with uranium mining site using RESRAD code

• Mr Khotso TsoloEnvironmental radiation risk assessment of a Nuclear Power Plant using CAP88 code

Nuclear Safety• MCNP is a general-purpose Monte Carlo N-

Particle code that can be used for neutron, photon, electron, or coupled neutron/photon/electron transport.

• Specific areas of application include radiation shielding, radiography, medical physics, nuclear criticality safety, detector design and analysis, Accelerator target design, Fission and Fusion reactor design, Decontamination and Decommissioning.

Nuclear Safety• RESRAD family of codes: Use for Environmental Risk Assessment

Nuclear Safety• CAP-88 Software:Use for Radiation Risk Assessment

Radiation Exposure Pathway

Nuclear ForensicsNuclear forensics is the technical means by which nuclear materials, whether intercepted intact or retrieved from post-explosion debris, are characterised (composition, physical condition, age, history) and interpreted (provenance, industrial history, and implications for nuclear device design). SCALE is a comprehensive modelling and simulation suite for nuclear safety analysis and design to perform reactor physics, criticality safety and spent fuel characterisation for nuclear facilities.

Origen-Arp is used for the characterisation of isotopic components of Spent Fuels.

Reactor: North Anna; Electrical Output: 903 MWe; Fuel Enrichment: 3.8%; Burn Up: 39 GWd/MTU; Fuel Cycle: 18 months; Power History: 78%; Fuel Type: W17X17

Nuclear Forensics Analysis

Provides information on the neutron flux