H. Gasper

Routine production of38K for medical use

A method for a simple and fast production of38K for medical use has been developed. Different target materials have been tested, yield of38K and contaminants examined and chemical procedure and target system developed.

Contribution to cyclotron targetry. II: Testing of teh target construction materials for 18F production via 20Ne(d, α)18F, recovery of 18F from various metal surfaces

In a previous article1 we reported results on the distribution of18F activity in the gas target. The present paper continues to report on experimental studies of physicochemical effects involved in the20Ne(d, α)18F reaction, with the aim to improve the recovery of18F in both chemical forms i.e.18Fe−F2 and18F−F− from the target, without adding fluorine carrier. The choice of optimum target construction material is a very important factor for achieving a high extraction rate and high specific activity of the product. Recovery and desorption of the18F-activity from the surfaces of various metal foils in the liquid and gas phases have been investigated. This study is of interest from both the practical and theoretical point of view.

Contribution to cyclotron targetry

Experimental methods for distribution and quantification of activity in a neon target bombarded by deuteron particles are presented and evaluated. Optimum target handling for medical radionuclide applications is important for achieving high yields, high specific activity, and a low rate of radiocontaminants with a minimum of cyclotron beam time. The mechanism of activity distribution and its importance are studied in relation to other considerations necessary for optimizing gas target performance in radiopharmaceutical applications.

An automated microprocessor controlled system for the production of a new type of81Rb−81mKr generator

Routine production of81Rb, utilizing the82Kr(p, 2n)81Rb reaction with natural krypton gas is described. Development and construction of a fully automated gas target system controlled by microprocess or is presented. A new type of81Rb−81mKr generator based on the sorption of81Rb on ion-exchange paper was developed and investigated in operation. It may be used either for gas-phase or for liquid elution of81mKr for different medical applications.

A feasibility study of75Br and77Br production from enriched krypton

Methods for the production of radiochemically pure bromine radionuclides were studied. Enriched target material yields were calculated from measurements based on experiments performed with non-enriched target gas. A special target system is to be developed.

Cyclotron production of34mCl for biomedical use

A method for simple and fast production of34mCl as tracer for biomedical research work has been developed. Different target materials have been tested, the yield of34mCl and co-produced contaminants examined, the fast chemical separation procedure developed and target system constructed.

Contribution to the cyclotron targetry

The radionuclide18F is of considerable interest for biochemical and physiological studies using positron emission tomography (PET). Of all methods used for its production only two have found wide application since their yield is high enough and the chemical form of the product is suitable for fluorination of organic compounds. Proton irradiation of enriched water using18O(p,n)18F reaction and deuteron bombardment of gaseous neon20Ne(d,α)18F process are the commonly used effective cyclotron production procedures. In our previous papers1,2 the different reactions and target parameters of the deuteron irradiation of neon gas were reported. In the present work, the production yields for the (d,α), (d,n) and (d,p) reactions were determined.

CONTRIBUTION TO CYCLOTRON TARGETRY V. MEASUREMENT OF THE TEMPERATURE IN A GAS TARGET DURING IRRADIATION

The direct measurement of the temperature in a gas target during irradiation was carried out as part of our comprehensive study on the20Ne(d, α)18Fe reaction and continues our previously published results.1–4The temperature in the gas target during irradiation with different beam currents is important for the knowledge of cyclotron targetry from both theoretical and practical points of view.

A new81Rb−81mKr generator from enriched82Kr gas for medical use

Present work describes the construction and results of a new81Rb production target system using highly enriched82Kr (99.95%) gas target material. The method yields a carrier-free product of highest activity and highest possible purity. It allows complete recovery of the expensive target material by freezing and avoids tedious chemical separation procedures. The remote-controlled target system has been constructed and functions extremely well.81Rb is used for the preparation of a new type of81Rb−81mKr generator with a capacity of approximately 60 mCi for use in nuclear medical diagnostic (lung ventillation studies and angioscintigraphy).