Use of ionic bombardment to increase the conductivity of metallized thin plastic films for making source mounts

Abstract

A study was made of the conductivity of thin flexible collodion films metallized either with gold (99.95%) or with gold -18% palladium alloy and the results obtained were compared with the conductivity of VYNS (a polyvinylchloride-acetate copolymer) films coated with the same metals. For both types of films the conductivity is better with the alloy, especially for VYNS. VYNS films coated with gold or the alloy show better conductivity than collodion coated with either metal. However, ionic bombardment of the collodion films prior t o metal coating considerably improves their conductivity, especially with the Au -1870 Pd alloy. For thid alloy the conductivity goes up by a factor of 100 t o 1 000 000, and then becomes better than that obtained with VYNS. Although ionic bombardment had a less pronounced effect on the VYNS, a n improvement in conductivity mas still observed.On a fait une Ctude comparative de la conductivitC de films minces de collodion e t de VYNS mCtallisCs soit avec de l'or, soit avec un alliage or -18Yo palladium, en couches variant de 2 & 30 pg/cm2. Pour les deux types de films, la conductivitC s'est rCvClCe meilleure avec l'alliage; de plus le VYNS devient plus facilement conducteur que le collodion. Toutefois, les films de collodion soumis & un bombardement ionique avant leur mCtallisation sont beaucoup plus faciles & rendre conducteurs e t leur conductivitC devient m$me supbrieure B celle obtenue avec les films de VYNS mCtallis6s par l'alliage. Quoique le bombardement ionique ait un effet moins prononce sur la conductivitC subsequente des films de VYNS, elle est tout d e meme amCliorCe de fason apprCciable. On dCcrit Cgalement des methodes simples e t rapides pour dCterminer I'Cpaisseur des films de collodion e t des couches mCtalliques dCposCes sur les films.

Method for Vacuum Evaporation of SiO on Thin Plastic Films

“…The thickness of the SiO layer is calculated from the weight of SiO evaporated from the crucible and the geometry of the evaporating system. 3 We have found that the uniformity and the homogeneity of radioactive sources prepared by air evaporation of the radioactive solutions on SiO deposits 100-300 A thick is greatly improved. For instance the self-absorption of the low energy beta of 63Ni in sources prepared by this technique was only 8%-10% as compared to the values of 30%-70% obtained by other methods commonly used in this field.…”

“…1 at a distance of about 12 cm from the crucible. It is a common type of mount used in the preparation of radioactive sources in 411" (3 counting. The evaporation of SiO was done with a "Speedivac" model 6E2 coating unit made by Edwards High Vacuum Ltd.…”

Volatilité du nitrate, chlorure et sulfure mercurique et préparation de sources radioactives de 203Hg

“…On doit s'attendre a ce qu'il en soit ainsi si les pertes sont dues 8 En fait, on peut dire que les pertes, s'il y en a, sont de beaucoup inftrieures 20.5% puisqu'il n'y a pas eu de contamination du systime de dttection durant l'tvaporation; nous sommes portts a croire qu'elles sont nulles.…”