RI source capsules

Overview

• Positron-emitting radioisotope source capsule for UHV conditions.
• Capsules are designed to be filled with ²²Na (²²NaCl or the standard ²²Na₂CO₃ ) with activities up to 3.7 GBq (100 mCi).
• Capsule geometrical design and materials are optimized for high positron emissivity and long-term operations.
• The capsules is bakeable up to 180°C (450 K) and operational from -270°C (4 K) to 180°C (450 K).

Source capsule design

The source capsule consists of 4 parts:

• The Titanium rear part ending in a stud for manipulating and fixing the source. The rear stud fatures a ring-shaped recession for better handling. Alternatively, it can be re-machined on request as 6-32 UNC (NEN-type source), M3 x 0.5 or M4 x 0.7 with a length of 0.25” (6.4mm).
• A 3.5 mm diameter Tantalum reflection plate with a 2 mm diameter and 250 µm deep recess is press-fitted into the Ti rear part. The radioisotope solute is being deposited carefully into the recess and dryed afterwards. The recess has an inclined side-wall in order to minimize positron absorption and scattering.
• The Titanium front part with the Titanium foil (5-8 µm thickness, 4 mm inner diameter) and side slits for easy handling using a manipulator (see below).
• A Titanium ring welded to the Titanium front part which fixed the foil and seals the capsule.

Each source capsule has been tested up to 5 bar overpressure. Moreover, the front part of each capsule was tested to be UHV tight down to 1E-8 Torr. The rear Ti part contains a cavity for the ²²Ne and CO₂ gases which are released following the decay of ²²Na. A small hole at the side connects the cavity with the front section for gas exchange. The overpressure of the released ²²Ne gas is less than 1 bar after all ²²Na has decayed.
A positron moderating foil (e.g. a W single crystal foil) can be attached using a ring-shaped clamp (user solution) at the front stubb of the source capsule. Contacting the Ti source foil with any object (scissors, knifes, sharp edges, cotton swabs, etc.) has to be avoided. Wipe tests of the Ti foil for radiation protection test have been performed after production and have to be avoided thereafter.

RI source supply

For ordering a source, please contact for international quotes: 

Ms. Debbie Christians
Radionuclide Production Group
iThemba LABS
P O Box 722, Somerset West 7130
South Africa
Tel: +27 (0)21 843 1338
Fax: +27 (0)21 843 1384

email: isotopes@tlabs.ac.za or d.christians@tlabs.ac.za
www: https://tlabs.ac.za/nuclear-medicine/radiopharmaceutical-and-radiochemicals-manufacturing/production/