Effects of fissioning nuclei distributions on fragment mass distributions for high energy fission
We study the effects of fissioning nuclei mass- and energy-distributions on the formation of fragments for fission induced by high energy probes. A Monte Carlo code called CRISP was used for obtaining mass distributions and spectra of the fissioning nuclei for reactions induced by 660 MeV protons on 241 Am and on 239 Np, by 500 MeV protons on 208 Pb, and by Bremsstrahlung photons with end-point energies at 50 MeV and 3500 MeV on 238 U. The results show that even at high excitation energies, asymmetric fission may still contribute significantly to the fission cross section of actinide nuclei, while it is the dominante mode in the case of lead. However, more precise data for high energy fission on actinide are necessary in order to allow definite conclusions.
In this paper we compute the packet error probability induced in a frequency hopped spread spectrum packet radio network. The frequency spectrum is divided into q frequency bins and the packets are divided into M bytes each. Every user in the network sends each of the M bytes of his packet at a frequency chosen among the q frequencies with equal probability, and independently of the frequencies chosen for other bytes (i.e. memoryless frequency-hopping patterns). Furthermore, statistically independent frequency hopping patterns correspond to different users in the network. We show that, although memoryless frequency hopping patterns are utilized, the byte errors at the receiver are not statistically independent" instead they exhibit a Markovian structure. We also compute the packet error probability induced when Reed-Solomon codes are used for the encoding of the packets.