Preliminary Results of IS Plasma Focus as a Breeder of Short-Lived Radioisotopes .sup.12C.sup.13N

Modified IS (Iranian Sun) plasma focus (10 kJ,15 kV, 94 [mu]F, 0.1 Hz) has been used to produce the short-lived radioisotope .sup.13N (half-life of 9.97 min) through .sup.12C(d,n).sup.13N nuclear reaction. The filling gas was 1.5-3 torr of hydrogen (60%) deuterium (40%) mixture. The target was solid nuclear grade graphite with 5 mm thick, 9 cm width and 13 in length. The activations of the exogenous target on average of 20 shots (only one-third acceptable) through 10-13 kV produced the 511 keV gamma rays. Another peak found at the 570 keV gamma of which both was measured by a NaI portable gamma spectrometer calibrated by a .sup.137Cs 0.25 [mu]Ci sealed reference source with its single line at 661.65 keV and .sup.22Na 0.1 [mu]Ci at 511 keV. To measure the gamma rays, the graphite target converts to three different phases; solid graphite, powder graphite, and powder graphite in water solution. The later phase approximately has a doubled activity with respect to the solid graphite target up to 0.5 [mu]Ci of 511 keV and 1.1 [mu]Ci of 570 keV gamma lines were produced. This increment in activity was perhaps due to structural transformation of graphite powder to nano-particles characteristic in liquid water.