29 research outputs found
Fusion-Fission of 16O+197Au at Sub-Barrier Energies
The recent discovery of heavy-ion fusion hindrance at far sub-barrier
energies has focused much attention on both experimental and theoretical
studies of this phenomenon. Most of the experimental evidence comes from
medium-heavy systems such as Ni+Ni to Zr+Zr, for which the compound system
decays primarily by charged-particle evaporation. In order to study heavier
systems, it is, however, necessary to measure also the fraction of the decay
that goes into fission fragments. In the present work we have, therefore,
measured the fission cross section of 16O+197Au down to unprecedented far
sub-barrier energies using a large position sensitive PPAC placed at backward
angles. The preliminary cross sections will be discussed and compared to
earlier studies at near-barrier energies. No conclusive evidence for
sub-barrier hindrance was found, probably because the measurements were not
extended to sufficiently low energies.Comment: Fusion06 - Intl. Conf. on Reaction Mechanisms and Nuclear Structure
at the Coulomb Barrier, San Servolo, Venezia, Italy, March 19-223, 2006 5
pages, 4 figure
Hindrance of Heavy-ion Fusion at Extreme Sub-Barrier Energies in Open-shell Colliding Systems
The excitation function for the fusion-evaporation reaction 64Ni+100Mo has
been measured down to a cross-section of ~5 nb. Extensive coupled-channels
calculations have been performed, which cannot reproduce the steep fall-off of
the excitation function at extreme sub-barrier energies. Thus, this system
exhibits a hindrance for fusion, a phenomenon that has been discovered only
recently. In the S-factor representation introduced to quantify the hindrance,
a maximum is observed at E_s=120.6 MeV, which corresponds to 90% of the
reference energy E_s^ref, a value expected from systematics of closed-shell
systems. A systematic analysis of Ni-induced fusion reactions leading to
compound nuclei with mass A=100-200 is presented in order to explore a possible
dependence of the fusion hindrance on nuclear structure.Comment: 10 pages, 9 figures, Submitted to Phys. Rev.
Experimental limits on nucleon decay and ÎB=2 processes
Results from the IMB collabration to detect possible proton decay in a salt mine near Cleveland, Ohio are presented. Detection apparatus is described.(AIP)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87900/2/1_1.pd
The search for proton decay
Following a very brief description of the theoretical developments which motivated the search for proton decay, I shall describe one of these experiments (the IMB experiment) in some detail. Then I shall compare recent results from that experiment with those from other detectors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87399/2/321_1.pd
IMB DetectorâThe first 30 Days
A large water Chernekov detector, located 2000 feet below ground, has recently been turned on. The primary purpose of the device is to measure nucleon stability to limits 100 times better than previous measurements. The properties of the detector are described along with its operating characteristics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87428/2/138_1.pd
Descriptions of new fossils, from the coal measures of Missouri and Kansas
by B.F. Shumard and G.C. SwallowExt. from Trans. Aca. Sci., St. Louis, Vol. I., No.
Recommended from our members
Report of progress of the Geological and agricultural survey of Texas
By B.F. Shumard, State Geologist. Printed by order of the eighth LegislatureUT Librarie
Independent Submission Request for Comments: 5456
IAX: Inter-Asterisk eXchange Version 2 This document describes IAX, the Inter-Asterisk eXchange protocol, an application-layer control and media protocol for creating, modifying, and terminating multimedia sessions over Internet Protocol (IP) networks. IAX was developed by the open source community for the Asterisk Private Branch Exchange (PBX) and is targeted primarily at Voice over Internet Protocol (VoIP) call control, but it can be used with streaming video or any other type of multimedia. IAX is an "all in one " protocol for handling multimedia in IP networks. It combines both control and media services in the same protocol. In addition, IAX uses a single UDP data stream on a static port greatly simplifying Network Address Translation (NAT) gateway traversal, eliminating the need for other protocols to work around NAT, and simplifying network and firewall management. IAX employs a compact encoding that decreases bandwidth usage and is well suited for Internet telephony service. In addition, its open nature permits new payload type additions needed to support additional services. Status of This Memo This document is not an Internet Standards Track specification; it is published for informational purposes. This is a contribution to the RFC Series, independently of any other RFC stream. The RFC Editor has chosen to publish this document at its discretion and makes no statement about its value for implementation or deployment. Documents approved for publication by the RFC Editor are not a candidate for any level of Interne
Reports on the geological survey of the state of Missouri. 1855-1871.
323 p. plates, 9 fold. maps. 26 cm