Study the neutron Fermi age for selected reactor shielding and radioactive waste materials

Other Title(s)

دراسة عمر فيرمي للنيترون لمواد مختارة لتدريج المفاعل و النفايات المشعة

Dissertant

Muslim, Ahmad Ghanim

Thesis advisor

Jasim, Mahdi Hadi

Comitee Members

Tawfiq, Nida Fadil
al-Mashhadani, Asya Hamid
Kazim, Aliyah Ahmad

University

University of Baghdad

Faculty

College of Science

Department

Department of Physics

University Country

Iraq

Degree

Master

Degree Date

2013

English Abstract

The Neutron Fermi Age, τ, and the neutron slowing down density, q(r,τ) , have been measured for some materials such as Graphite, Iron, Perspex, Aluminum, Copper and radioactive waste by using two typical techniques; gamma spectrometric system UCS-30 with [NaI (Tl)] detector and passive detector (SSNTDs 'LR-115 type 2' with BN1 converter screen).

The former technique was applied for Graphite and Iron materials by using Indium foils covered by Cadmium and the measurements done at Indium resonance of 1.46 eV.

The latter is other technique which was not previously reported for measuring the Fermi Age and it was applied for Perspex, Aluminum, Copper and radioactive waste in addition to Graphite and Iron materials.

All of these materials are exposed to a plane 241Am/Be neutron source with recent activity 38 mCi.

The measurements of the Fermi Age which obtained by the first technique were found to be τ = 297 ± 21 cm2 for Graphite, τ = 400 ± 28 cm2 for Iron and for the second technique were found to be τ = 268 ± 19 cm2 for Graphite, τ = 333 ± 29 cm2 for Iron, τ = 156 ± 12 cm2 for Perspex, τ = 290 ± 20 cm2 for Aluminum, τ = 346 ± 24 cm2 for Copper and τ = 213 ± 17 cm2 for radioactive waste (irradiated Aluminum by 60Co and 59Fe isotopes).

The results of Graphite and Iron explained that the two different techniques were capable of making the measurements with acceptable error, although not with equal degree of bias and uncertainty.

Neutron slowing down density was also calculated depending on the recent experimental τ value and distance.

In addition to: 1) Providing the TROXLER equipment model 3401which contain a plane 241Am/Be neutron source and 137Cs gamma source and disassembling it to get the neutron source and shielding it by using paraffin wax, these procedures are monitored by using; portable radiation device (identiFINDER ultra to alarm the user from the high exposure (according to alarm setup)), film badge, electronic personal dosimeter (thermo) to determine the personal exposure, and some protective clothes.

2) Calculation the nominal output and the flux of the present plane 241Am/Be neutron source which were found to be 1.406 ×109 ns-1 and 6×107 n.cm-2 s-1, respectively.

3) Create new empirical formula for calculation the neutron Fermi Age which is very important to reduce many experimental procedures depending on the atomic mass number (A), number of collisions (Nc) and diffusion coefficient of neutron (D).

Main Subjects

Physics

Topics

• Nuclear energy
• Nuclear physics
• Nuclear reactors
• Quantum theory

No. of Pages

127

Table of Contents

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-606752