DD223854A1 - CONTAINERS FOR GASOFMIC SAMPLES FOR IRRADIATION TO ACCELERATORS - Google Patents

Abstract

The invention relates to a container for Gasefoermige samples for irradiation to accelerators with the aim to produce especially short-lived radionuclides. The task of specifying such a container with the simplest possible structure with reliable function, is solved by a glass cylinder is gas-tightly closed at one end with a bottom with Fuellstutzen and at the other end by a metal window, the metal window on the outside to a support edge bent and plan ground wall of the cylinder is glued. Such a container can also serve as a storage and transport for the target gas and be reused several times.

Description

Containers for gaseous samples for irradiation on accelerators ... ; '·

Field of application, the invention ^;

The invention relates to a container for gaseous samples for irradiation on accelerators with the aim of producing in particular short-lived radionuclides.

Characteristic of the known technical solutions

Short lived radionuclides, e.g. For example, fluorine-18, are prepared from the: talking, gaseous target by activation with charged particles in accelerators. The target gas to be activated must be enclosed in suitable containers for this purpose. ,. . '

Known are containers that are closed by fusing, welding or screwing, but have the disadvantage that they must be destroyed after the irradiation. It was therefore proposed (DD-WT 44-347) to equip the cavity of the container with a controllable valve and to arrange a recess and a conical ground in the opening of the valve perpendicular to its longitudinal axis. This container, however, since it has no entrance window, only suitable for the irradiation of gases and liquids - with uncharged particles. ''

Another proposal (DE-AS 23 21 552) provides to surround the reaction zone with a winding tube, which is closed at the side with a window through which the loading

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Radiation of the gas filling takes place on the outer surface of the reaction chamber heating elements for heating the Reaktionsζone are arranged and at the opposite ends of the .Reaktionskammer are controllable by valves openings for the inlet of _: target gas and a Spülgäses or for the AusIaJJ. of the purge gas containing the generated radionuclide provided. : . ' /,:

This container has the disadvantage that, for the most part, it has to be manufactured from ultrapure nickel or Monet alloy. The . formed: Radionuclide must be expelled from the surface of the container by heat and carrier gas purging. During the irradiation: with alpha particles it often happens due to / overheating, to rupture the metallic entrance window, whereby disturbances in the. Vacuum system of the accelerator may occur. , .. '-'. ' , [. '·' ^

The same applies to containers in which the reaction chamber is lined with hard equipment glass (J.Lucl. Med. 1_2 (1971) 6 ,: 362). The removal of the radionuclide from the chamber takes place by washing with a suitable solution , It is necessary to separate any impurities present by passing the wash solution over ion exchange resins.

Object of the invention

The object of the invention is a low expenditure 'producible λund broadly usable container for gaseous samples for irradiation to accelerators. , , -

Explanation of the essence of the invention

The invention has for its object to find such a construction for the container, which 'by a simple Auf • baü easy handling and rapid isolation of the. Radionuclides are guaranteed «The container should be reusable.

The container according to the invention is a cylindrical vessel (ampoule) of hard glass or quartz glass, which has at one end a bottom mit.einem (side mounted) filler neck and is closed at the other end by a metal window, the gas-tight on the outside to an edge bent and ground flat wall of the container is glued. As a window metal foils, especially from Al, Ei, Ta or 72A, with. Layer thicknesses around 20, to .. used. As an adhesive z. B. epoxy resins. To ensure adequate stability, the support for the metal foil should be about 1 cm wide. The diameter of the container is chosen so that already takes advantage of the beam cross-section of the accelerator and on the other hand, the adhesive surface is not hit by the beam, otherwise a multiple reuse of the container is in question.

The length of the vessel is not critical. However, it can also be adapted to the given specific conditions (eg by observing the range of the beam in a larger length sample vessel or by calculation).

The use of the container described is simple. The target gas is brought via the filler into the previously evacuated interior and the filler neck melted. As a rule, the target gas in the container is not under increased pressure. Thus, these containers can also serve as storage and transport means for the target gas * Zur.Herstellung of the desired radionuclide, the container is attached to the accelerator and carried out the irradiation. For longer loading Radiation times, it is convenient to cool the metal window with a compressed air flow. For 3-channel current measurement, the discharge cable can be connected directly to the metal window. After irradiation, the radionuclide formed during the irradiation and condensed on the vessel wall is readily eluted by a suitable solvent. For this purpose, the container is aerated either by piercing the irradiation window or by opening the filler neck, the solvent, for. As water or a physiological saline

solution, introduced and the radionuclide detached from the wall "The rapid elution prevents chemical reactions with the container material. So that Radiönuklid falls in high quality and can be separated with 'Good yields ^";. ·';.. '''^..''·....

The container can be reused several times. , '...

The container according to the invention has a number of advantages: The production is simple; it can, according to the wishes of the user (different degree of enrichment of the, stable, target isotopes, amount of target gas, etc.) separate from the accelerator, even in the long term before irradiation, with the target gas filling; and serve as storage and means of transport. Before, during, and after irradiation no special gas feed is required.

Implementation Guide : ...

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'. To obtain the radionuclide Ρ becomes the nuclear reaction

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¥ e (d, «-) Έ exploited. This will be: a. Quartz glass cylinder with, an inner diameter of 20 mm and a .Länge of 1400 mm used. The one end is closed by a bottom with a laterally disposed filler neck, at the other end is the. Wall, 'bent outwards to an edge about 1 cm wide. This edge was ground flat and serves as a support for a metal window / 20 yum thick tantalum foil. The film is glued vacuum-tight with · E-Ooxidharzkleber. The container will close,

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next evacuated and then with Heongas, the 90.92 % Ue

20 2 ^holds:, filled to a Flächndichte of 100.13 mg le / .cm. The target gas is irradiated in an accelerator with deuterons of energy 11 MeV. Immediately after the end of irradiation, the formed P-, which has been deposited on the wall of the container, is eluted with physiological saline. In this way, .2, 6.1 0 · Ba F / zuAh are obtained.

Claims (2)

Srfindungsanspruch 1, Behälter.für gaseous samples for irradiation to accelerators for obtaining in particular short-lived radionuclides, characterized in that it is a cylindrical • vessel of tempered glass or quartz glass represents ,. that has at one end a bottom with a filler neck and on. whose end is closed by a metal window, which is glued gas-tight on the outside bent to a support edge and ground flat wall of the container. 2. Container according to item 1, characterized in that the window consists of an Al, Hi-, Ta- or V2A film with layer thicknesses of 20 to.