Search for heavy-ion emission in Cf-249 decay - art. no. 037301

Using phosphate glass detectors PKS-50, we have searched for possible emiss ion of heavy clusters in the decay of Cf-249 with the aim of confirming the result obtained from a recent gamma ray spectrometry experiment. After a 2 0-day exposure to a 7.4 MBq activity Cf-249 source of 37.5 cm(2) PKS-50 gla sses covered with polymide foils to stop fission fragments, no ions with 17 less than or equal to Z less than or equal to 21 were detected. We could d educe an upper Limit of the branching ratio (90% C.L.) b less than or equal to 1.5 X 10(-12) and a partial half-life T-1/2 greater than or equal to 7. 4 X 10(21) s. According to calculations performed on the basis of the prefo rmed cluster model there seems to be very little chance that such an exotic decay might be detected, at least in the next few years. [S0556-2813(99)07 408-7].