الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Radionuclides are finding increasing applications in almost all branches of science and technology, particularly in the field of medicine. The relatively long-lived radionuclide 139Ce (T1/2 = 137.6 d) is useful as a standard for the calibration of γ-ray detectors. This radioisotope can be produced through 139La (p,n)139Ce with Q-value -1.06037 MeV and has only one strong γ-ray of energy 165.857 keV with 80 % intensity, which is within the optimum energy range for detection with a gamma camera. Image degradation during single photon emission tomography (SPECT) due to attenuation and Compton scattering of photons can cause clinical image artifacts. The neutron rich isotope 142Pr (T1/2 = 19.13 h) has good physical characteristics for internal radiotherapy. The wide use of 142Pr almost relates to the β- emission of maximum energy 2.16 MeV and an average energy of 0.83 MeV, as well as rather adequate intensity (93 %). 142Pr has another advantage, It emits one gamma photon at 1.58 MeV with an intensity of 3.7% which does not interfere with internal medical applications due to its relatively low intensity and low specific γ-dose constant.
The main aim of the present work was to develop efficient separation methods for those radionuclides from cyclotron irradiated targets. In particular two systems were investigated in detail:
• Separation of radiocerium from irradiated lanthanum target
• Separation of praseodymium from lanthanum as a simulation mode for the production of 142Pr from α-particles induced reaction on La2O3 target.
The thesis is composed of three chapters.
Chapter 1: Introduction
Some details about the employed cyclotron and its constituents are given.
•An overview of the importance and production routes of relevant radionuclides is given.
• The chemistry of lanthanum, cerium and praseodymium is also given. At the end of this chapter, a literature survey on the separation chemistry of cerium and praseodymium is outlined.
•The main aim of the present work is to develop efficient separation methods for those radionuclides from cyclotron irradiated targets.
Chapter 2: Experimental Method
The experimental part defines the chemicals used and includes separation procedures for Ce and Pr after an extensive study on the distribution coefficients of La, Ce and Pr using different aqueous solutions by ion-exchange chromatography and different extractants by solvent extraction techniques. Also this chapter includes detailed description for production and separation of no-carrier-added 139Ce from irradiated natural lanthanum by Dowex 50W-X8 using chelating agent α-HIBA and using solvent extraction techniques with three extractants, namely, tri butyl phosphate (TBP), tri phenyl phosphine oxide (TPPO) and diethyl ether (DEE). The quality control of the product is an integral part of this aspect of work.
Chapter 3: Results and Discussin
This chapter consists of two parts.
• First part, the separation of cerium from lanthanum by solvent extraction and ion exchange chromatography techniques with particularly reference to produce no-carrier-added 139Ce.
• The second part contains a separation of praseodymium from lanthanum also by solvent extraction and ion exchange chromatography techniques as a simulation mode for the production of 142Pr from α-particle reaction on La2O3 target .