Cm-244-based alpha-sources for space exploration

Open alpha-sources for the Alpha-PXM apparatus are designed and manufacture d. This equipment is intended for analysis of the elemental composition of the Mars surface rocks and atmosphere by alpha-backscattering, alpha-proton scattering, and X-ray fluorescence methods. The sources are manufactured b y high-temperature condensation of metallic curium vapor onto silicon subst rates, The sources are silicon disks with Cm-244 fixed on their surfaces as silicides. The disks have the following dimensions (mm): diameter 8, activ e segment diameter 6, and thickness 0.3. The sources are characterized by t he activity of 5 +/- 1 mCi, the proper half-width of the alpha-line equal t o 1.7-2.5%, and the alpha-line width at 1/10 of the peak height, to 2.9-4.5 % of the mean energy of alpha-particles of 5.8 MeV. The sources preserve th eir characteristics after mechanical and service-life tests at temperatures from -196 to 1000 degrees C in a vacuum. The sources are suitable for the above-mentioned analytical purposes.