Study of 236U/238U ratio at CIRCE using a 16-strip silicon detector with a TOF system.

Accelerator Mass Spectrometry (AMS) is presently the most sensitive technique for the measurement of long-lived actinides, e.g. ²³⁶U and ^xPu isotopes. A new actinide AMS system, based on a 3-MV pelletron tandem accelerator, is operated at the Center for Isotopic Research on Cultural and Environmental Heritage (CIRCE) in Caserta, Italy. In this paper we report on the procedure adopted to increase the ²³⁶U abundance sensitivity as low as possible. The energy and position determinations of the ²³⁶U ions, using a 16-strip silicon detector have been obtained. A ²³⁶U/²³⁸U isotopic ratio background level of about 2.9x10^-11 was obtained, summing over all the strips, using a Time of Flight-Energy (TOF-E) system with a 16-strip silicon detector (4.9x10^-12 just with one strip). [ABSTRACT FROM AUTHOR]