D ETERMINATION OF ELEMENTAL COMPOSITIONS BY USING NEUTRON RESONANCE SPECTROSCOPIC M AHMOUD G AAFAR T EACHING ASSISTANT, PHYSICS F ACULTY OF SCIENCE, MENOUFIA UNIVERSITY

OUTLINE ECR I ON S OURCES I NTENSE R ESONANCE N EUTRON S OURCE (IREN) N EUTRON R ESONANCE C APTURE A NALYSIS N EUTRON R ESONANCE C APTURE A NALYSIS E XAMPLE -> C U -Z N A LLOY E XAMPLE -> C U -Z N A LLOY

ECR Ion Source

4 Ion source Axial injection system ECR ion source

5 The ECR ion source ω ECR ~ B× e /m e

6 DECRIS-2 – U-400M cyclotron – 1995 ECR-4M – U-400 cyclotron – 1996 (collaboration FLNR – GANIL (France)) DECRIS-3 – TESLA Accelerator Installation (Belgrade) DECRIS-2m – BIONT Inc. (Bratislava) – 2003 DECRIS-SC – CI-100 cyclotron DECRIS-3 - DC-60 accelerator complex (Astana, Kazakhstan) – 2006 DECRIS-4 – in operation at the test bench DECRIS-2m – tested DC-72 cyclotron (Bratislava) DECRIS-SC2 – new ion source for U-400M – under commissioning DECRIS-SC3 – for DC-350 cyclotron - project DECRIS - Dubna ECR Ion Sources DECRIS-2, DECRIS-2m, DECRIS-3, DECRIS-4 are “room temperature” ECR ion sources. The axial magnetic field is created by two coils with independent power supplies. The radial magnetic field is created by permanent magnet hexapole, made from NdFeB. DECRIS-SC – axial magnetic field is created by superconducting solenoids

7 FLNR (JINR) CYCLOTRONS WITH ECR ION SOURCES NEW CYCLOTRONS CI DECRIS-SC U400 + ECR4M U400M + DECRIS-2 DC-72 DECRIS-2m DC-60 DECRIS-3

I NTENSE R ESONANCE N EUTRON S OURCE (IREN) Pulsed Source for Applied and fundamental Investigations

The IREN source of three basic parts: 1) Vertically electron linear accelerator (linac) LUE ) Vacuum pipeline for transportation of the electron beam to the electron-neutron converter. 3) Electron – neutron converter located in the center of material absorbes charged radiation (blanket). The IREN Source

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11 M AIN PARAMETERS OF THE LINAC LUE -200 Max. Electron Energy 75 MeV Av. electron energy 30 MeV Pulse current 2.8 A Pulse width100 ns Repetition rate50 Hz Beam power~1kW Neutron intensity~10 12 n/s

Neutron Resonance Capture Analysis used to determine the elemental composition of materials and artifacts

Interaction of neutrons with nuclei as a function of neutron energy shows sharp peaks, known as resonances, at energies specific for each isotope. Resonances are thus the fingerprints of elements. They can be visualized in the neutron capture spectrum as a function of neutron energy. The energy of a neutron can be determined by measuring the time of flight ( the time it needs to travel a known distance L in m). With a pulsed neutron source the time-of-flight (T in µs) can be determined from the start pulse of the source and a stop pulse generated by detection of the prompt capture gamma rays.

14 T IME OF FLIGHT NEUTRON SPECTROSCOPY Detector Flight path L, m Source Collimator Sample dt E XPERIMENTAL FACILITY 1.Photo multiplier, 2. Sample, 3. scintillator section Large volume liquid scintillator detector consisting of 6 sections 20 liters each was placed at 60 meters flight path. Sample installed inside the detector.

15 The energy of a neutron can be determined by Time of flight Energy channel.no (TDC)

Before Calculation

18 R AW EXPERIMENTAL DATA

T HE CALIBRATION LINE

A CKNOWLEDGEMENT S PECIAL T HANKS TO P ROF. P AVEL S EDYSHEV (FLNP) T HANKS TO JINR T HANKS TO ASRT - E GYPT S PECIAL T HANKS TO P ROF. B ORIS (FLNR)

T HANKS T HANKS