Հայաստանի ատենախոսությունների բաց մատչելիության պահոց = Open Access Repository of the Armenian Electronic Theses and Dissertations (Armenian ETD-OA) = Репозиторий диссертаций Армении открытого доступа

Արագացուցչային մեթոդներով տեխնեցիում 99մ ստանալու համար թիրախի պատրաստման և մշակման ու փնջի վերահսկման տեխնոլոգիաները

Հարությունյան, Գևորգ Սուրենի (2016) Արագացուցչային մեթոդներով տեխնեցիում 99մ ստանալու համար թիրախի պատրաստման և մշակման ու փնջի վերահսկման տեխնոլոգիաները. PhD thesis, Ա. Ի. Ալիխանյանի անվան ազգային գիտական լաբորատորիա (Երևանի ֆիզիկայի ինստիտուտ).

[img] PDF (Thesis)
Available under License Creative Commons Attribution.

Download (19Mb)
    [img]
    Preview
    PDF (Abstract)
    Available under License Creative Commons Attribution.

    Download (1196Kb) | Preview

      Abstract

      Within the last decade accelerator-based methods of medical isotopes production are under active discussion. These have a number of advantages over currently used reactor-based production methods. The most convenient way of production is by exploiting the proton cyclotron, which was installed near ANSL and can be exploited for 99mTc isotope production, commonly used in medicine. A few technical challenges were solved for the application of this method: target preparation and surface processing using laser beam, investigation of the possibility of a new cryogenic method for cooling the target during irradiation, investigation of proton beam profile measurement technique using vibrating wire scanner, the opportunity of recovery of expensive enriched bi-product of the irradiation - Mo100, and Tc extraction after irradiation, and a number of other technical and technological problems. In the present work R&D of technology of disc target preparatiom from metallic Mo powder has been performed. To improve its mechanical strength and thermo conductivity a laser-beam processing of its surface has been applied. A quality assessment of the produced target has been done. For target cooling during irradiation a special optimized system using liquid nitrogen has been calculated, projected, assembled and tested. The qualitative results of the test-experiment showed the applicability of this method. It will allow to double the proton beam intensity for the irradiation, which will increase the 99mTc production efficiency. For beam profile monitoring a new device has been assembled, based on the measurement of vibrating wire oscillation frequency. To calculate the thermophysical processes inside the target during irradiation the finite element method has been apllyed using the ANSYS software. Results were obtained for different beam profile widths, which will allow choosing optimal beam intensity and transversal distribution on the target surface from the thermal point of view. For recycled use of very expensive enriched 100Mo target material complex equipment has been designed and assembled, allowing to recover Mo from solution using chemical technologies. In the first step the MoS3 is being recovered from base solution. Then in two steps MoS3 is transformed to MoO3 and then to metallic Mo. The recovering efficiency is ~95% and quality of recovered Mo is quite high. For last two steps a high temperature oven has been installed providing up to 1200 oC. To check the radiochemical purity of produced 99mTc a computer-driven gamma scanner has been projected, assembled and tested. For testing a 99mTc from reactor-based Mo/Tc generator has been used, to prove the usability of the gamma scanner. All of the above-mentioned devices and systems were tested and have shown full operability and high efficiency, and are ready to be exploited in the full technological chain with target irradiation under proton beam of the cyclotron.

      Item Type: Thesis (PhD)
      Additional Information: Արագացուցչային մեթոդներով տեխնեցիում 99մ ստանալու համար թիրախի պատրաստման և մշակման ու փնջի վերահսկման տեխնոլոգիաները: Accelerator based methods of technetium99m production – target preparation and processing and beam monitoring technologies.
      Uncontrolled Keywords: Հարությունյան Գևորգ Սուրենի,
      Subjects: Physics
      Divisions: UNSPECIFIED
      Depositing User: NLA Circ. Dpt.
      Date Deposited: 11 Oct 2016 11:34
      Last Modified: 11 Oct 2016 11:34
      URI: http://etd.asj-oa.am/id/eprint/3585

      Actions (login required)

      View Item