FRANK LABORTORY OF NEUTRON PHYSICS

Vu Duc Phu

Institute of Physics ( IOP)

10 Dao Tan-Ba Dinh-Ha Noi-Viet Nam

JOINT INSTITUTE FOR NUCLEAR RESEARCH

ContentsStructure of Frank Laboratory

of Neutron Physics

Three main facilities of FLNP

Three main techniques: RBS, ERDA, PIXE

Structure of Frank Laboratory of Neutron Physics

- FLNP -

Directorate

• Director: Valery Nickolaevich Shvetsov• Laboratory Scientific Leader: Viktor Lazarevich

Aksenov

Scientific Departments

• Division of Nuclear Physics - DNP• Division of Condensed Matter Research and

Development - DCMRDTechnical Departments

• Reactor IBR -2• IREN facility• EG -5

Division of Nuclear Physics - DNP

Leader of department: Valery Nickolaevich Shvetsov

Sector 1

• Investigations of Neutron-nuclear Interactions

Sector 2

• Investigations of Neutron Fundamental Properties

Sector 3

• Neutron Activation Analysis and Applied Research

Division of Condensed Matter Research and Development - DCMRD

Department of Neutron Investigations of

Condensed Matter –DNICM

• Studies of the structure and dynamics of solids, liquids and other condensed systems using and developing neutron scattering methods.

Department of Spectrometers Complex – DSC

• Provide electronics for neutron experiments on the EG-5 and reactor IBR-2

Three main facilities of FLNP

IBR-2 Pulsed Reactor

IREN Facility

EG-5 Accelerator

IBR-2 Pulsed Reactor Parameters Average power: 2 MW Fuel: PuO2 Number of fuel

assemblies: 69 Pulse repetition rate: 5,

10 Hz Thermal neutron flux density

from the surface of the moderator:• Time average: ~ 1013

n/cm²·s• Burst maximum: ~ 1016

n/cm²·s

IREN FacilityIntense Resonance Neutron Source

Parameters Peak current: 3 A Repetition rate: 50 Hz Electron pulse duration: 100 ns Electron energy: 30 MeV Beam power: 0.4 kW Multiplication: 1 Neutron intensity: 1011 n/s

EG-5 Van De Graaff Accelerator It was built in 1965 in

Dubna The beam of the accelerated

ions is applied for investigation of the depth distributions of all elements in different samples, using analytical methods : RBS/NR, ERDA and PIXE.

Typical Structure of Van De Graaff Accelerator

EG-5 Van De Graaff Accelerator

Parameters of EG-5:Energy Region : 0.9-

3.5 MeV Beam intensity for H+ : 30μA Beam intensity for He+ :

10μA Energy Spread <500

eV Number of beam lines : 6

EG-5 Van De Graaff Accelerator

RBS-Rutherford Backscattering Spectrometry

HistoryThe Geiger–Marsden

experiment (1909 – 1914)

E. Rutherford give the atom model (1911)

Discovered the nucleus

RBS-Rutherford Backscattering Spectrometry

Thomson model and Rutherford model

RBS-Rutherford Backscattering Spectrometry

• Elastic collision between incident light particle (projectile) with the energy E0 and stationary nucleus (target)

• Scattering kinematic factor :

(apply the conversation of energy and momentum)

• Scattering cross section:

(CM)

- Rutherford’s Formula -

RBS-Rutherford Backscattering Spectrometry

Characteristics of RBS:Near-surface layer analysis of

solids Very sensitive for heavy

elements Elemental composition Depth profiling of individual

elements

RBS-Rutherford Backscattering Spectrometry

A typical spectra of RBS

ERDA – Elastic Recoil Detection Analysis

ERDA was first demonstrated by L’Ecuyer et al. in 1976

ERDA – Elastic Recoil Detection Analysis

ERDA – Elastic Recoil Detection Analysis

Recoil Kinematic Factor :

Recoil cross section

Characteristics of ERDA: Depth profiling of lightest

elements ( H, D,T) High resolution

ERDA – Elastic Recoil Detection Analysis

A typical spectra of ERDA

PIXE – Particle Induced X-ray Emision

History1895, W. Röntgen discovered X-

ray1909, C.G Barkla discovered

Characteristic X-rayPIXE was first proposed in 1970

by Sven Johansson of Lund University, Sweden

PIXE – Particle Induced X-ray Emision

W. Röntgen

PIXE – Particle Induced X-ray Emision

Bohr Model : introduced by Niels Bohr in 1913

quantum physical interpretation

Explained the spectral emission lines of atomic hydrogen

Then in 1913, H. Moseley give the empirical law of Characteristic X-ray - Moseley’s Law

Bohr Model

PIXE – Particle Induced X-ray Emision

Moseley’s Law:

– Rydberg’s constant Z – atomic number – screening constant n – main quantum number frequency of X-ray quantum

Characteristics of PIXE: High Sensitivity The setup of experiment is

simular one of RBS

PIXE – Particle Induced X-ray Emision

Thank for your attention !!!