From MoS DAB use ONE LINK per entry, SHORT descriptions. AVOID piping, external links, redlinks with little potential wiktionary fission Fission is a splitting of something into two parts. Fission may refer to In physics, nuclear fission is a process where a large atomic nucleus such as uranium is split into two smaller particles. In biology, fission biology is the subdivision of a cell or a multi cellular body into one or more parts and the regeneration of each of the parts into a complete individual. In anthropology, secession fission is the process whereby a nation state divides and becomes multiple states Other uses Fission band , a Swedish melodic death metal band disambiguation da Fission flertydig de Fission es Fisi n desambiguaci n lt Skilimas no Fisjon ... more details
Image ThermalFissionYield.svg thumb 350px Fission product yields by mass for thermal neutron fission ... 233 U 233 used in the thorium cycle . Ternary fission is a comparatively rare 0.2 to 0.4 of events type of nuclear fission in which three charged products are produced rather than two. As in other nuclear fission processes, other uncharged particles such as multiple neutron s and gamma ray s are produced in ternary fission. Ternary fission may happen during neutron induced fission or in spontaneous fission the type of radioactive decay . About 25 more ternary fission happens in spontaneous fission compared to the same fissioning system formed after thermal neutron capture, ref http www linux.gsi.de wolle FISSION ternary node1.html Fraction ternary fission as a function of different ... reaction system of thermal neutron induced fission. Products The most common nuclear fission process is binary fission. It produces two charged asymmetrical Nuclear fission product fission products ... fission of large nuclei, the binary process happens merely because it is the most ... ternary fission process produces three positively charged fragments plus neutrons, which are not charged ... in the usual ternary fusion, the most common small fragments from ternary fission are helium 4 nuclei .... The second most common particles produced in ternary fission are Triton physics triton s the nuclei ... ternary fission, particularly when alphas are produced, are quite similar in size distribution to those produced in binary fission. Product energies The energy of the third much smaller product usually ranges between 10 and 20 MeV. In keeping with their origin, alpha particles produced by ternary fission ... media . The other two larger fragments carry away, in their kinetic energies, the remainder of the fission kinetic energy typically totalling 170 MeV in heavy element fission that does not appear as the 10 ... in ternary fission are each less energetic, by a typical 5 to 10 MeV, than they are seen to be in binary ... more details
Mitochondria can divide by fission and since they require mitochondrial DNA for their function, fission is coordinated with Mitochondrial DNA Replication DNA replication . Some of the proteins that are involved in mitochondrial fission have been identified and some of them are associated with mitochondrial disease s. ref Cite pmid 21776419 ref Mechanism The DNM1L Drp1 protein is a member of the Dynamin family of large GTPases . Drp1 controls the final part of mitochondrial fission, pinching off the membrane stalk between two forming daughter mitochondria. The MFN2 protein is part of a complex that links the endoplasmic reticulum ER to mitochondria. Points of ER mitochondrial association have been associated with the formation of Drp1 complexes and mitochondrial fission. ref Cite pmid 21885730 ref Several Drp1 binding proteins have been identified. ref Cite pmid 21772324 ref A protein called mitochondrial fission factor Mff binds Drp1 and promotes mitochondrial fission. ref Cite pmid 21149567 ref The FIS1 protein might recruit Drp1 to sites of fission ref Cite pmid 21647385 ref but it might require association with another protein, MIEF1 coded for by the SMCR7L gene , to promote mitochondrial fission. In contrast, MIEF1 when bound to Drp1 might prevent mitochondrial fission and thus shift the balance towards fusion of mitochondria. ref Cite pmid 21701560 ref References reflist Category Mitochondria ... more details
unreferenced date March 2009 Fast fission is nuclear fissionfission that occurs when a heavy atom absorbs a high energy neutron , called a fast neutron , and splits. Most fissionable materials need thermal neutron s, which move slower. Fast reactors vs. thermal reactors Fast neutron reactor s use fast fission to produce energy, unlike most nuclear reactor s. In a conventional reactor, a Neutron moderator moderator is needed to slow down the neutrons so that they are more likely to fission atoms. A fast neutron reactor uses fast neutrons, so it does not use a moderator. Moderators may absorb a lot of neutrons in a thermal reactor , and fast fission produces a higher average number of neutrons per fission, so fast reactors have better neutron economy making a plutonium breeder reactor possible. However, a fast neutron reactor must use relatively highly enriched uranium or plutonium so that the neutrons have a better chance of fissioning atoms. Fissionable but not fissile Some atoms, notably uranium 238 , do not usually undergo fission when struck by slow neutrons, but do split when struck with neutrons of high enough energy. The fast neutrons produced in a hydrogen bomb by fusion of deuterium and tritium have still higher energy than the fast neutrons produced in a nuclear reactor ... expedient of adding layers of cheap natural uranium. In fact, fast fission of uranium 238 provides ... bomb. Fast fission of uranium 238 does also occur in fission bomb s. Differences in fission product yield A graph of fission product yield against the mass number of the fission fragments has two pronounced but fairly flat peaks, at around 90 to 100, and 130 to 140. With thermal neutrons, yields of fission ... , Sn 126 , and Sb 127 are very low. The higher the energy of the state that undergoes nuclear fission, the more likely a symmetric fission is, hence as the neutron energy increases and or the energy ... 235 U 235 , when the neutrons are thermal neutron s. The curves for the fission of the later actinides ... more details
Cold fission or cold nuclear fission is defined as involving fission events for which fission fragments have such low excitation energy that no neutron s or gamma s are emitted. Cold fission events have so low a probability of occurrence that it is necessary to use a high flux nuclear Nuclear reactor technology reactor to study them. The first observation of cold fission events was in experiments on fission induced by thermal neutrons of uranium 233 , uranium 235 ref C. Signarbieux et al. . http hal.archives ouvertes.fr jpa 00231968 en Evidence for nucleon pair breaking even in the coldest scission configurations of sup 234 sup U and sup 236 sup U , Journal de Physique Lettres Vol 42, No 19 1981 ... www.springerlink.com content gw7v12v1713250r7 Mass and kinetic energy distribution in cold fission ... fission were also done involving sup 248 sup Cm ref A Sandulescu et al. http www.iop.org EJ abstract 0954 3899 22 7 003 The cold fission of 248Cm , Journal of Physics. G Nucear and Particle. Physics ... cold fission of 252Cf , Journal Physics G Nuclear and Particle Physics, Volume 28 October, 2002 ... of cold fission , Nuclear Physics A, Volume 530, Issue 1 July, 1991, DOI 10.1016 0375 9474 91 90754 ... i5 p2516 1 Cold fission description with constant and varying mass asymmetries , Physical Review C, Volume 57 1998, DOI 10.1103 PhysRevC.57.2516, pp. 2516 2522 ref The importance of cold fission phenomena .... The fact that cold fission preserves nuclear mass energy mass until the fission fragments reach the detectors permits the experimenter to better determine the fission dynamics, especially the aspects related to Coulomb and shell effects in low energy fission. ref Modesto Montoya, http www.informaworld.com ... induced cold fission of U 233, U 235, and Pu 239 , Radiation Effects and Defects in Solids, Volume ... w5u431755126g7h6 Coulomb effects in low energy fission Zeitschrift f r Physik A , Springer Berlin ... results. References Reflist DEFAULTSORT Cold Fission Category Nuclear chemistry Category ... more details
Spontaneous fission SF is a form of radioactive decay characteristic of very heavy isotope s. Because ... masses. Because of constraints in constructing the daughter fission product nuclei, spontaneous fission ... are in theory subject to spontaneous fission, are niobium 93 and molybdenum 94 elements 41 and 42 respectively . Spontaneous fission has never been observered in naturally occurring isotopes of these ligher elements, however. Operationally they are stable isotope s. In practice, spontaneous fission ... primordial nuclide that has been observed to undergo spontaneous fission. The elements most susceptible to spontaneous fission are the artificially produced high atomic number actinide ... . For uranium and thorium, spontaneous fission mode of decay does occur, as noted, but it is not seen ... containing these elements. Mathematically, the criterion for whether spontaneous fission can occur ... number and A is the mass number e.g., 235 for U 235 . As the name suggests, spontaneous fission gives much the same result as induced nuclear fission . However, like other forms of radioactive decay, it occurs ... as in induced nuclear fission. Spontaneous fissions release neutrons as all fissions do, so if a critical mass is present, a spontaneous fission can initiate a self sustaining chain reaction. Also, radioisotopes for which spontaneous fission is a nonnegligible decay mode may be used as neutron sources ... of the amount of nuclei that can spontaneously fission, this is a Poisson process for very short time intervals the probability of a spontaneous fission is proportional to the length of time. The spontaneous fission of uranium 238 leaves trails of damage in uranium bearing minerals as the fission fragments recoil through the crystal structure . These trails, or fission tracks , provide the basis for the radiometric dating technique known as fission track dating . Spontaneous fission rates Spontaneous fission rates ref cite book last Shultis first J. Kenneth coauthors Richard E. Faw title Fundamentals ... more details
Orphan date December 2010 Fission Wall coord 85 52 S 155 12 W source GNIS is a granite cliff, convert 1,400 m high, on the north face of Mount Griffith , Hays Mountains , in the Queen Maud Mountains of Antarctica. The feature was climbed on November 16, 1987, by a United States Antarctic Research Program Arizona State University geological party led by Edmund Stump . The name derives from granite samples collected on the wall at convert 100 m spacing for dating by the Fission track dating fission track method. ref name gnis References Reflist refs ref name gnis cite gnis type antarid id 4956 name Fission Wall accessdate 2012 03 24 ref usgs gazetteer id 4956 Category Cliffs of the Ross Dependency Category Amundsen Coast RossDependency geo stub ... more details
Unreferenced date March 2008 The fission sail is a type of spacecraft propulsion proposed by Robert Forward that uses nuclear fissionfission fragments to propel a large solar sail like craft. It is similar in concept to the fission fragment rocket in that the fission by products are directly harnessed as working mass , and differs primarily in the way that the fragments are used for thrust. In the fission sail, the rocket is built in the form of a two layer sheet, with some sort of absorber on one side, and nuclear fuel on the other. Atoms in the fuel that decay will release their fragments in random, but opposite, directions. In the simple case where the decay releases the fragments front and rear , the rearward moving fragment generates thrust directly, while the frontward moving one is absorbed in the front half of the sail, also contributing thrust. The system must be built very large in order to ensure that those fragments that are not moving directly to the front of rear nevertheless tend to hit the sail somewhere. A sail several kilometers on a side would have fairly good capture ratios . The sail is not a nuclear reactor , and relies on natural decay rates for energy release. The thrust from such a system will always be very low, albeit extremely efficient. Another problem is that the sail receives the energy equally over the entire sail surface, and thus can t be steered. This differs from a solar sail, where tilting the sail to the sunlight can produce a sideways thrust for steering. Forward proposed the system as an add on to existing solar sails. Close to stars where the light density is high the sails work fine, but as they move past about 2 astronomical unit AU their thrust is too low to be useful. Forward suggested that coating the sail with fissionable material would provide thrust in this region, where maneuvering is no longer as important. Such a system ... Category Nuclear spacecraft propulsion fr Propulsion par fragments de fission ... more details
Infobox musical artist See Wikipedia WikiProject Musicians name Fission image caption image size background group or band alias origin Sweden genre Thrash metal , melodic death metal years active 2002 present label Napalm Records Napalm associated acts website current members Andreas Hedlund Vintersorg br Benny H gglund past members notable instruments Fission is a Sweden Swedish melodic death metal band formed in 2002. The band began as Benny H gglund s personal project, with the hopes of fusing melody and aggression into his music. After writing some material, he decided to seek aid from Andreas Hedlund of Vintersorg , the band in which H gglund plays live session drums. After recording a two track demo with Benny handling all instrumentation and Andreas handling vocal duties, they signed on with Austrian label, Napalm Records . Benny continued writing all of the songs for their first full length, while Andreas provided all of the lyrics, vocals, keyboards, and sound effects. They released their first full length Crater album Crater on April 27, 2004. ref http fission.se ibiography.htm Fission.se Feb 2005 ... Biography February 2, 2005. ref Discography Crater album Crater 2004 Pain Parade 2008 References reflist External links http fission.se Official website MySpace fissionsweden Fission http www.napalmrecords.com promo fissionp.html Fission at Napalm Records DEFAULTSORT Fission Category Swedish melodic death metal musical groups Category Musical groups established in 2002 metal music stub de Fission Band ... more details
File Binary fission.svg 180px right thumb Binary fission in a prokaryote e.g., a bacterium In biology, fission is the subdivision of a cell or body, population, or species into two or more parts and the regeneration of those parts into separate cells bodies, populations, or species . ref name Carlson07 cite book last Carlson first B. M. title Principals of regenerative biology. year 2007 publisher Elsevier Academic Press pages 379 isbn 0123694396 ref ref name Boulay10 cite journal last1 Boulay first1 R. L. last2 Galarza first2 J. A. last3 Che first3 B. last4 Hefetz first4 A. last5 Lenoir first5 A. last6 van Oudenhove first6 L. last7 Cerda first7 X. title Intraspecific competition affects population size and resource allocation in an ant dispersing by colony fission. journal Ecology volume 91 issue 11 pages 3312 3321 year 2010 doi 10.1890 09 1520.1 url http www.esajournals.org doi full 10.1890 09 1520.1 ref ref name Hubbell03 cite journal last Hubbell first S. title Modes of speciation and the lifespans ... Oikos volume 100 issue 1 pages 193 199 year 2003 doi 10.1034 j.1600 0706.2003.12450.x ref Binary fission produces two separate cells, populations, species, etc., whereas multiple fission produces more than two cells, populations, species, etc. Binary fission of prokaryotes Prokaryotic fission , which is binary fission, is a form of asexual reproduction and cell division used by all prokaryote s, bacteria ... genetic material. Multiple fission of protists Multiple fission at the cellular level occurs ... 76146 Multiple fission title Cell reproduction publisher Encyclop dia Britannica ref ref name ..., multiple fission, or schizogony , is manifested either as protozoal merogony merogony , sporogony or gametogony ... PA125 v onepage&q Fissiparity&f false ref See also Cytokinesis , cell division in eukaryotes Fission ... 2 DEFAULTSORT Binary Fission Category Bacteria Category Cell cycle Category Reproduction ar ... nl Binaire deling ja pt Fiss o bin ria simple Binary fission ... more details
Infobox webcomic title Fission Chicken image Image FisChic.jpg caption Fission Chicken has problems with the TV. Art by J.P. Morgan. author J.P. Morgan cartoonist J.P. Morgan url http www.fissionchicken.com status Weekly began 1987 online April 16, 2006 ended genre Superhero , Anthropomorphism Anthropomorphic Parody ratings Fission Chicken is a comic book and webcomic character created by J.P. Morgan cartoonist J.P. Morgan 1957 2010 . Fission Chicken is a short tempered superhero chicken who can fly, is extremely strong , bulletproof , and can project power bolts from his hands. Starting in 1987, Fission Chicken appeared in numerous stories published in the comic book Critters Fantagraphics Books , as well as his own series from the same publisher. Other appearances over the years include Plan Nine from Vortox MU Press , appearances in Furrlough Radio Comix , Valiant Varmints and SFA Spotlight 14 Shanda Fantasy Arts . Pages by J.P. Morgan can also be read on the Fission Chicken website. Fission Chicken Fish for short fights a continuing battle against weird monsters and cultural brain death. Notably, he has battled the mind control attempts of Vortoxians a malevolent race of alien marketing experts , the Ditsy entertainment empire a parody of The Walt Disney Company , and Video Zombies. Some unusual opponents he has fought include the Ether Bunny a rabbit bank robber who uses airborne incapacitating agents on his victims , Percival Ulmer P.U. Evolcraft a somewhat deranged occultist and a satire on H. P. Lovecraft , ambulatory living toilets, the movie monster Ferdie Cruller a pun on Nightmare on Elm Street Freddy Kruger , the Richard Sharpe Shaver Dero a subterranean race ..., Fission Chicken does not use an alias to hide his identity, and simply goes by the name Fission ... in New Jersey, and his friend Skip Squirrelhard is his upstairs neighbor. Fission Chicken creator John ... Rovin, Jeff . Fission Chicken entry in The Illustrated Encyclopedia of Cartoon Animals Prentice Hall ... more details
unreferenced date February 2008 Loop fission or loop distribution is a compiler optimization technique attempting to break a loop into multiple loops over the same index range but each taking only a part of the loop s body. The goal is to break down large loop body into smaller ones to achieve better utilization of locality of reference . It is the reverse action to loop fusion . This optimization is most efficient in multi core processors that can split a task into multiple tasks for each processor. border 1 cellpadding 1 Original loop After loop fission pre int i, a 100 , b 100 for i 0 i 100 i a i 1 b i 2 pre pre int i, a 100 , b 100 for i 0 i 100 i a i 1 for i 0 i 100 i b i 2 pre Further reading cite book author Kennedy, Ken & Allen, Randy. title Optimizing Compilers for Modern Architectures A Dependence based Approach publisher Morgan Kaufmann year 2001 isbn 1 55860 286 0 See also Loop transformation Loop fusion References http sc.tamu.edu help power powerlearn html ScalarOptnw sld031.htm Loop fission Category Compiler optimizations ... more details
Infobox album See Wikipedia WikiProject Albums Name Fission Type studio Artist Jens Johansson Cover Jens Johansson 1998 Fission.jpg Released 1998 Recorded Moon Path Alpha in Malm , Sweden Starec Grammophone in V xj , Sweden East Side Recorders in New York City , New York Big Noise Studios in New York City, New York Heptagon Remote in Andersl v , Sweden Genre Jazz fusion , instrumental rock Length 68 39 Label Heptagon Producer Jens Johansson Last album Sonic Winter br 1997 This album Fission br 1998 Next album The Last Viking br 1999 Misc Extra album cover Upper caption Alternative cover Type studio Cover Jens Johansson 1998 Fission alternative .jpg Lower caption United States edition Album ratings rev1 Allmusic rev1Score Rating 4 5 ref Allmusic class album id r341774 pure url yes Allmusic review ref Fission is a studio album by keyboardist Jens Johansson , released in 1998 through Heptagon Records Europe , Pony Canyon Pony Canyon, Inc. Japan and Shrapnel Records United States . According to Johansson, the album went through an extremely troubled recording process due to several mishaps with Andy West s bassline bass parts, which ultimately never made the album. ref Jens Johansson Johansson, Jens 2000 06 04 . http www.panix.com jens parse.cgi faq more.par A list of some other FAQ s . panix.com. Retrieved 2011 12 28. ref Track listing tracklist all writing Jens Johansson title1 Hooded Strangers length1 10 41 title2 Phase Camouflage length2 6 49 title3 Zero Sum Game length3 3 36 title4 Acrostic Shibboleth length4 8 12 title5 Don t Mention the War length5 10 49 title6 Race Condition length6 7 32 title7 Crowd Tectonics length7 6 15 title8 Nystagmus length8 3 59 title9 Beautiful Lung Dogs length9 10 46 total length 68 39 Personnel Jens Johansson keyboard instrument keyboard , synthesizer Bass synthesizer bass synthesizer , record producer production Shawn Lane guitar tracks ... References reflist DEFAULTSORT Fission Album Category Jens Johansson albums Category 1998 albums ... more details
Refimprove date December 2009 Similar to how the fission fragment rocket produces thrust, a fission fragment reactor is a nuclear reactor that generates electricity by decelerating an ion beam of Nuclear fissionfission byproducts instead of using nuclear reactions to generate heat . By doing so, it bypasses the Carnot cycle and can achieve efficiencies of up to 90 instead of 40 45 attainable by efficient turbine driven thermal reactors. Fission fragment reactor designs generally have several common components. The reactor chamber contains a high surface area nuclear fuel to both facilitate direct emission of fission fragments and assist in cooling the fuel. Generally, if fuels subject to criticality are used instead of those that naturally radioactive decay decay as in a nuclear battery , a neutron moderator moderator is typically involved as well. A magnetic mirror induced by an axial magnetic field typically collates the fragments into a beam that can then be decelerated to electricity generation generate power . The rate the particles decelerate at depends on their energy as a consequence, the deceleration process also can help provide isotopic separation as an automatic nuclear reprocessing reprocessing stage. An earlier design by scientists at Idaho National Engineering Laboratory and Lawrence Livermore National Laboratory involved the concept of coating fine carbon wires with fissionable fuel. While this had a high surface area, it proved not enough to radiate the heat absorbed during the reactions, so their design was modified to rotate long wires through the core, giving them time to cool. A later design by Rodney A. Clark and Robert B. Sheldon ref http www.rbsp.info rbs RbS PDF aiaa05.pdf Dusty Plasma Based Fission Fragment Nuclear Reactor, 41st AIAA ASME SAE ASEE ... area enough to allow for effective radiative cooling. As the particles naturally ionize as fission ... Reflist External links DEFAULTSORT Fission Fragment Reactor Category Nuclear reactors ... more details
Fission track dating is a radiometric dating technique based on analyses of the damage trails, or tracks, left by Nuclear fissionfission fragments in certain uranium bearing mineral s and glass es. ref ... publisher University of California Press , Berkeley year 1975 ref Fission track dating is a relatively ... of different Archaeology archeological artifacts. The method involves using the number of fission ... of rock cooling below closure temperature . Fission tracks are sensitive to heat, and therefore ... using fission tracks is aimed at a understanding the evolution of mountain belts b determining ... artifacts. Method Unlike other isotopic dating methods, the Decay product daughter in fission ... fission decay at a known rate, and it is the only isotope with a decay rate that is relevant to the significant production of natural fission tracks other isotopes have fission decay rates too slow to be of consequence. The fragments emitted by this fission process leave trails of damage fossil ... etching of polished internal surfaces of these minerals reveals spontaneous fission tracks, and the track ... to the grain surface. The neutron irradiation induces fission of uranium 235 in the sample, and the resulting ... 235 U 238 ratio is well known and assumed constant in nature. To determine the number of induced fission ... induced fission of the uranium 235 in the sample creates induced tracks in the overlying external ... through a mass spectrometer . Applications Unlike many other dating techniques, fission track dating ... uranium epidote s and garnet s may be used for very old samples Paleozoic to Precambrian . The fission ... in mountain belts. Fission tracks are preserved in a crystal when the ambient temperature ... causes the fission damage to heal or anneal, the technique is useful for dating the most recent ... geothermal Vein geology vein formation. The fission track method has also been used to date archaeological ..., these minerals grains retain information about the source rock. Fission track analysis of these minerals ... more details
PBB geneid 56947 Mitochondrial fission factor Mff is a protein that in humans is encoded by the MFF gene . ref name entrez cite web title Entrez Gene mitochondrial fission factor url http www.ncbi.nlm.nih.gov sites entrez?Db gene&Cmd ShowDetailView&TermToSearch 56947 accessdate ref Mff is an outer mitochondrial membrane protein that binds to the DNM1L Drp1 GTPases GTPase that controls mitochondrial fission . The Mff Drp1 complex promotes mitochondrial fission. ref Cite pmid 21149567 ref Mff also regulates peroxisome morphology. ref Cite pmid 18353969 ref References reflist Further reading refbegin cite journal author Igci YZ, Arslan A, Akarsu E, et al. title Differential expression of a set of genes in follicular and classic variants of papillary thyroid carcinoma. journal Endocr. Pathol. volume 22 issue 2 pages 86 96 year 2011 pmid 21509594 doi 10.1007 s12022 011 9157 8 refend gene 2 stub Category Mitochondria ... more details
Nucleon pair breaking in fission has been an important topic in nuclear physics for decades. The most measured quantities in research on nuclear fission are the charge and mass fragments yields for uranium 235 and other transuranic s. In this sense, experimental results on charge distribution for low energy fission of actinides present a preference to even Z fragment, which is called odd even effect on charge yield. ref http prola.aps.org abstract PRL v34 i16 p1034 1 G. Siegert et al. . Nuclear Charge Distributions in the Isobars 92 to 100 Resulting from Thermal Neutron Fission of Uranium 235 , Physical Review Letters , American Physical Society, Volume 34, No 16 1975, doi 10.1103 PhysRevLett.34.1034 , pp. 1034 1036 ref The importance of these distributions is because they are the result of rearrangement of nucleons on the fission process due to the interplay between collective variables and individual particle levels therefore they permit to understand several aspects of dynamics of fission process. The process from saddle when nucleus begins its irreversible evolution to fragmentation to scission point when fragments are formed and nuclear interaction between fragments dispels , fissioning system shape changes but also promote nucleons to excited particle levels. Because, for even Z proton number and even N neutron number nuclei, there is a gap from ground state to first excited particle state which is reached by nucleon pair breaking , fragments with even Z is expected to have a higher probability to be produced than those with odd Z. The preference even Z even N divisions ... by the hypothesis that in fission process always there will be nucleon pair breaking, which may be proton pair o neutron pair breaking in low energy fission of uranium 234, uranium 236, ref http hal.archives ... and kinetic energy distribution in cold fission of sup 233 sup U, sup 235 sup U and sup 239 sup Pu ..., 1984, doi 10.1007 BF01415636 , pp. 219 225 ref References Reflist Category Fission products physics ... more details
Long lived fission products are radioactive materials with a long half life more than 200,000 years produced by nuclear fission . Evolution of radioactivity in nuclear waste Nuclear fission produces fission products , as well as actinide s from nuclear fuel nuclei that capture neutrons but fail to fission ... term The high short term radioactivity of spent nuclear fuel is primarily from fission products with short half life . The radioactivity in the fission product mixture is mostly short lived isotopes such as Iodine ... an open air nuclear detonation where all the fission products are dispersed. Medium lived fission products Medium lived fission products After several years of cooling, most radioactivity is from the fission ... half lives of about 30 years. Other fission products with similar half lives have much lower fission ... lived fission product s. ref cite book title Nuclear Wastes Technologies for Separations and Transmutation url http books.google.com books?id iRI7Cx2D4e4C&pg PA23&lpg PA23&dq 22medium lived fission products ... decayed to low levels, the bulk of radioactivity from spent fuel come not from fission products but actinides ... reactor s, or fusion reactor s. Long lived fission products On scales greater than 10 sup 5 sup years, fission products, chiefly sup 99 sup Tc, again represent a significant proportion of the remaining ... 242 , if those have not been destroyed. The most abundant long lived fission products have total ... energy around 4 5 MeV. Only seven fission products have long half lives, and these are much longer than 30 years, in the range of 200,000 to 16 million years. These are known as long lived fission ... fission products, not as beta decay products of more neutron rich initial fission products. The shadowed fission products have yields on the order of one millionth as much as iodine 129. The 7 long lived fission products Long lived fission products The first three have similar half lives, between ... in very small quantities in fission by thermal neutrons , so the energy per unit time from sup ... more details
Refimprove date May 2011 Image Fission fragment propulsion.svg 250px thumb right Fission fragment propulsion concept br a fissionable filaments, b revolving disks, br c reactor core, d fragments exhaust The fission fragment rocket is a rocket engine design that directly harnesses hot nuclear fission product s for thrust , as opposed to using a separate fluid as working mass . The design can, in theory, produce very high specific impulse s while still being well within the abilities of current technologies. Design considerations In traditional nuclear thermal rocket and related designs, the nuclear energy is generated in some form of reactor and used to heat a working fluid to generate thrust ... fission are at a temperature of millions of degrees, which is then spread out into the surrounding fuel, resulting in an overall temperature of a few thousand. In the fission fragment design, it is the individual atoms that actually undergo fission that are used to provide thrust, by extracting ... such that the outermost layers of a fuel bundle will be most likely to undergo fission, the high temperature ... Dusty plasma bed reactor.svg 400px right thumb Dusty plasma bed reactor br A fission fragments ejected for propulsion br B reactor br C fission fragments decelerated for power generation br d moderator ... fuel made the bundles go critical. The fission fragments at the surface of the bundles would break ... elements would make the overall performance of the fission fragment system lower. Nonetheless, the system ... and decreases complexity of a fission fragment rocket at the same time over the bundle proposal. ref Clark, R. Sheldon, R. http www.rbsp.info rbs RbS PDF aiaa05.pdf Dusty Plasma Based Fission ... electric field . As the nanoparticles ionization ionize as fission occurs, the dust becomes ... sub sp sub . See also Fission fragment reactor References references clr spacecraft propulsion Nuclear propulsion Category Nuclear spacecraft propulsion fr Propulsion par fragments de fission ... more details
Nuclear fission products are the atomic fragments left after a large atomic nucleus Nuclear fission fissions ... , gamma ray s and neutrino s. The two smaller nuclei are the fission products . See Fission products by element . Ternary fission , about 0.2 to 0.4 of fissions, also produces a third light nucleus ... produced by the fission of one fissile atom is always less than the atomic weight of the original atom. This is because some of the mass is lost as free neutron s, and once kinetic energy of the fission ... to be missing from the cooled fission products. Since the nuclei that can readily undergo fission are particularly neutron rich e.g. 61 of the nucleon s in uranium 235 are neutrons , the initial fission products are almost always more neutron rich than stable nuclei of the same mass as the fission product e.g. stable ruthenium 100 is 56 neutrons stable xenon 134 is 60 . The initial fission products ... to a proton with each beta emission. Fission products do not emit alpha particles . A few neutron rich and short lived initial fission products first decay by emitting a neutron. This is the source ... decays are rapid and may release high energy beta particle s or gamma radiation . However, as the fission ... years means a slow rate of radiation release, and the fission product yield yield of this nuclide per fission is very low Radioactivity over time Actinidesvsfissionproducts Fission products have half lives of 90 years Samarium 151 or less, except for seven long lived fission product s with half lives of 211,100 years Technetium 99 and more. Therefore the total radioactivity of fission products ... by fission, such as the Integral Fast Reactor and molten salt reactor , use this fact to claim that within ... web 20071009064447 www.nuc.berkeley.edu designs ifr anlw.html ref Fission products emit ... . Yield Main Fission product yield Image ThermalFissionYield.svg thumb 350px Fission product yields by mass for thermal neutron fission of Uranium 235 U 235 , Pu 239 , a combination of the two ... more details
Image ThermalFissionYield.svg thumb 350px Fission product yields by mass for thermal neutron fission ... in the fission product mixture from the nuclear fission of an actinide such as uranium or plutonium ... Se R Iso2 Se 79 79 Se G Iso1 80 Se R Iso1 82 Se R Se 79 is one of the long lived fission products . Bromine ... Kr R Krypton 85 is formed by the fission process with a fission yield of about 0.3 . Only 20 of the fission ... and other fission gases like the more abundant xenon are released. Increase of Nuclear fissionfission gases above a certain limit can lead to fuel pin swelling and even puncture, so that fission ... 88, 89, 90 Medium lived fission products Iso1 88 Sr R Iso1 89 Sr I Iso1 Sr 90 90 Sr G The strontium ... emitter with a half life of 28.8 years. Its fission product yield decreases as the mass of the fissile ... somewhat less than 1 in a fission product mixture which has been allowed to age for months or years ... by the fission process some of this are short lived radioactives sup 95 sup Zr and sup 97 sup Zr which decay to molybdenum , while almost 10 of the fission products mixture after years of decay consists ... of 1.53 million years which is one of the 7 major long lived fission product s. In PUREX plants ... 95 with a halflife of 35 days is initially present as a fission product. The only stable isotope of niobium has mass number 93, and fission products of mass 93 become stable zirconium 93. Molybdenum 95, 97, 98, 100 Iso1 95 Mo R Iso1 97 Mo R Iso1 98 Mo R Iso1 99 Mo V Iso1 100 Mo O The fission product mixture contains significant amounts of molybdenum . Technetium 99 Long lived fission products Iso2 Tc 99 99 Tc Y technetium 99 sup 99 sup Tc is produced at a yield of about 6 per fission see also the main fission product s page. Ruthenium 101 to 106 Iso1 101 Ru R Iso1 102 Ru R Iso1 103 Ru I Iso1 ... is formed by the fission process. The ruthenium in PUREX raffinate can become oxidized to form ruthenium ... the ruthenium became volatile and behaved differently from many of the other metallic fission products ... more details
Hybrid nuclear fusion fission hybrid nuclear power is a proposed means of generating Electrical power industry power by use of a combination of nuclear fusion and Nuclear fissionfission processes. The concept ... the excess neutrons from the fusion reaction to in turn cause a high yield fission reaction close to 100 in the surrounding subcritical fissionable blanket, the net yield from the hybrid fusion fission .... Unlike a conventional fission reactor , the fusion hybrid can consume almost all of the uranium ... versus storage of spent nuclear fuel without reprocessing. Activation product Fission by products .... Safety In contrast to current commercial fission reactors, hybrid reactors potentially demonstrate ... and decay heat removal is possible via passive mechanisms. The fission is driven by neutrons ... shut off or the process is disrupted by a mechanical failure, the fission damping damps ... sustaining, level. The inherent danger of a conventional fission reactor is any situation leading ... configuration the fission and fusion reactions are decoupled , i.e. while the fusion neutron output drives the fission, the fission output has no effect whatsoever on the fusion reaction, completely ... nuclear fuel and waste streams. Fusion driven fission also offers the possibility of using Thorium ... can allow normally non fissioning U 238 to undergo fission directly without conversion first to Pu ... spallation to generate additional neutrons can be used to enhance the fission output, with the caveat ... are capable of directly causing fission in both Thorium and U 238, the lower energy neutrons produced ... of spallation used in the design. See also Traveling wave reactor , a pure fission reactor ... Uranium as a fuel. Generation IV reactor , next generation fission reactor designs claiming much higher ... to generate non self sustaining fission Hybrid Fusion Fission Reactors fall into this category . References Reflist Hybrid Fission Fusion Reactor Initiated by a Laser, A.P. Barzilov, A.V. Gulevich ... more details
Image Gabon Geology Oklo.svg right thumb Geological situation in Gabon leading to natural nuclear fission ... nuclear fission reactor is a uranium mineral deposit deposit where analysis of isotope ratio s has ... and consists of 16 sites at which self sustaining nuclear fission reactions took place approximately ... Holliger, P. Blanc, P. L. year 1996 month title Natural fission reactors in the Franceville Basin ... fission reactor. Other observations led to the same conclusion, and on September 25, 1972, the CEA ... 2 billion years ago. Later, other natural nuclear fission reactors were discovered in the region. Fission product isotope signatures Nd Image Neodymium isotope signatures.svg thumb right Isotope signatures of natural neodymium and fission product neodymium from SimpleNuclide2 uranium 235 which had ... thumb right Isotope signatures of natural ruthenium and fission product ruthenium from ... with that for fission product ruthenium which is the result of the Nuclear fissionfission of SimpleNuclide2 uranium 235 with thermal neutrons. It is clear that the fission ruthenium has a different isotope signature. The level of SimpleNuclide2 ruthenium 100 in the fission product mixture is low ... chain reaction took place. The heat generated from the nuclear fission caused the groundwater to boil ... and the reaction started again. These fission reactions were sustained for hundreds of thousands of years, until a chain reaction could no longer be supported. Fission of uranium normally produces five known isotopes of the fission product gas xenon all five have been found trapped in the remnants ... Rosman, K. J. R. Smith, C. L. year 1980 month title The Oklo Natural Reactor Cumulative Fission Yields and Retentivity of the Symmetric Mass Region Fission Products journal Earth and Planetary Science ... ref Most of the non volatile fission products and actinides have only moved centimeters in the veins ... the natural nuclear fission reactors in Gabon Africa journal Comptes Rendus Physique volume 3 ... more details
main Fission product Long lived fission products Nuclear fission splits a heavy nucleus such as uranium or plutonium into two lighter nuclei, which are called fission products . Yield refers to the fraction of a fission product produced per fission. Yield can be broken down by Individual isotope Chemical ... chain of beta decay . Isotope and element yields will change as the fission products undergo beta decay ... fission products delayed neutron s , with halflife measured in seconds. A few isotopes can be produced directly by fission, but not by beta decay because the would be precursor with atomic number ..., they have very low yields less than a millionth as much as common fission products because they are far ... per fission, so that the total yield percentages sum to 200 . Less often, it is stated as percentage of all fission products, so that the percentages sum to 100 . Ternary fission , about 0.2 to 0.4 of fissions, also produces a third light nucleus such as helium 4 90 or tritium 7 . Medium lived fission products Mass vs. yield curve Image fission yield volatile.png thumb 450px From Fluoride volatility .... Yields at 10 sup 0,1,2,3 sup years after Nuclear fissionfission , not considering later neutron ... 155 Gadolinium Gd visible. Image ThermalFissionYield.svg thumb 450px Fission product yields by mass for thermal neutron fission of U 235, Pu 239, a combination of the two typical of current nuclear ... of fission products against the atomic number of the fragments is drawn then it has two peaks, one in the area zirconium through to palladium and one at xenon through to neodymium . This is because the fission ... cchieh cact nuctek fissionyield.html Yield vs. Z This is a typical distribution for the fission of uranium . Note that in the calculations used to make this graph the activation of fission products was ignored and the fission was assumed to occur in a single moment rather than a length of time. In this bar chart results are shown for different cooling times time after fission . Because of the stability ... more details
In primatology , a fission fusion society is one in which the social group, e.g. bonobo collectives of 100 strong, sleep in one locality together, but forage in small groups going off in different directions during the day. This form of social organization occurs in several other species of primates , though usually less organised and less social than bonobos e.g. chimpanzees, hamadryas, gelada baboons, spider monkeys, and humans cn date January 2012 , most carnivores including the spotted hyena , African lion , and cetaceans such as bottlenose dolphins , ungulates such as deer , and fish such as guppy guppies . These societies change frequently in their size and composition, making up a permanent social group called the parent group. Permanent social networks consist of all individual members of a faunal community and often varies to track changes in their environment and based on individual animal dynamics. In a fission fusion society, the main parent group can fracture fission into smaller stable subgroups or individuals to adapt to Social environment environmental or social circumstances. For example, a number of males may break off from the main group in order to hunt or forage for food during the day, but at night they may return to join fusion the primary group to share food and partake in other activities. Overlapping of so called parent groups territorially is also frequent, resulting in more interaction and mingling of community members, further altering the make up of the parent group. This results in instances where, say, a female chimpanzee may generally belong to one parent group, but encounters a male who belongs to a neighboring community. If they copulate , the female may stay with the male for several days and come into contact with his parent group, temporarily fusing into the male s community. In some cases, animals may leave one parent group in favor ... determinants of fission fusion dynamics in the spotted hyaena. Animal Behaviour 76 619 636 ... more details
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