Patent Number: 
Section: claims

1. A container for accommodating a radioactive source comprising: wherein said first helix loosely mates with said second helix thereby attenuating leakage of radiation from said container through said gap when said radioactive source is accommodated therein. a shielded housing having a bore extending therein;  a removable sleeve adapted for insertion into said bore, said removable sleeve comprising a chamber for receiving a radioactive source;  said housing and said removable sleeve defining a gap formed there between when said removable sleeve is inserted into said bore;  a first helix located on a surface of said housing facing into said bore;  a second helix located on said removable sleeve, 2. The container according to  claim 1 , wherein axial rotation of said removable sleeve with respect to said housing moves said removable sleeve between a withdrawn position and an inserted position within said housing. claim 1 3. The container according to  claim 1 , wherein said removable sleeve is a sample delivery assembly. claim 1 4. The container according to  claim 3 , wherein said container is an irradiator. claim 3 5. The container according to  claim 1 , wherein said removable sleeve is a source delivery assembly. claim 1 6. The container according to  claim 5 , wherein said container is a radiation storage or transport container. claim 5 7. The container according to  claim 1 , wherein said housing accommodates the radioactive source peripheral of said bore. claim 1 8. The container according to  claim 1 , wherein said chamber opens to a sidewall of said removable sleeve. claim 1 9. The container according to  claim 1 , wherein said bore comprises a region of expanded cross-section for receiving a radioactive source at the periphery thereof. claim 1 10. The container according to  claim 9 , wherein said housing is adapted to receive said radioactive source in an annular configuration within said bore in said region of expanded cross-section. claim 9 11. The container according to  claim 10 , wherein the first helix is interrupted in said region of expanded cross-section. claim 10 12. The container according to  claim 1 , said sleeve having a longitudinal axis, said container additionally comprising rotation imparting means to impart axial rotation about said longitudinal axis to said sleeve. claim 1 13. The container according to  claim 12 , wherein said rotation imparting means comprises a motor. claim 12 14. The container according to  claim 12 , wherein said rotation imparting means is manually operable. claim 12 15. The container according to  claim 12 , additionally comprising longitudinal drive means to impart movement to said in the direction of said longitudinal axis. claim 12 16. The container of  claim 1 , wherein said first and second helix are integrally formed on the surface of said housing and said removable sleeve, respectively. claim 1 17. The container of  claim 1  wherein said first and second helix are affixed to the surface of said housing said removable sleeve, respectively. claim 1