Fission of heavy nuclei induced by stopped antiprotons. II. Correlations between fission fragments

Kim, Y.S.; Iljinov, A. S.; Mebel, M. V.; Hofmann, Peter; Daniel, H.; Egidy, T. von; Haninger, T.; Hartmann, F. J.; Machner, H.; Plendl, H.S.; Riepe, G.

doi:10.1103/physrevc.54.2469

Cited by 20 publications

(11 citation statements)

References 15 publications

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“…This uncertainty is mainly due to the lack of information on the fission-fragment mass in the present work. Similar attempts for classifying the events with respect to E * were made in previous works performed in normal kinematics by exploiting either the mass loss [131,132] or the total light-particle multiplicity [78]. At best, an accuracy of (10-30)% in E * was reached.…”

Section: Manifestation and Magnitude Of Transient Effects 1) Modelmentioning

confidence: 53%

Fragmentation of spherical radioactive heavy nuclei as a novel probe of transient effects in fission

Schmitt

Schmidt²,

Kelić³

et al. 2010

Phys. Rev. C

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38 pages, 15 figuresPeripheral collisions with radioactive heavy-ion beams at relativistic energies are discussed as an innovative approach for probing the transient regime experienced by fissile systems evolving towards quasi-equilibrium. A dedicated experiment using the advanced technical installations of GSI, Darmstadt, permitted to realize ideal conditions for the investigation of relaxation effects in the meta-stable well. Combined with a highly sensitive experimental signature, it provides a measure of the transient effects with respect to the flux over the fission barrier. Within a two-step reaction process, 45 proton-rich unstable spherical isotopes produced by projectile-fragmentation of a stable 238U beam have been used as secondary projectiles. The fragmentation of the radioactive projectiles on lead results in nearly spherical compound nuclei which span a wide range in excitation energy and fissility. The decay of these excited systems by fission is studied with a dedicated set-up which permits the detection of both fission products in coincidence and the determination of their atomic numbers with high resolution. The width of the fission-fragment nuclear charge distribution is shown to be specifically sensitive to pre-saddle transient effects and is used to establish a clock for the passage of the saddle point. The comparison of the experimental results with model calculations points to a fission delay of (3.3+/-0.7).10-21s for initially spherical compound nuclei, independent of excitation energy and fissility. This value suggests a nuclear dissipation strength at small deformation of (4.5+/-0.5).1021s-1. The very specific combination of the physics and technical equipment exploited in this work sheds light on previous controversial conclusions

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Section: Manifestation and Magnitude Of Transient Effects 1) Modelmentioning

confidence: 53%

Fragmentation of spherical radioactive heavy nuclei as a novel probe of transient effects in fission

Schmitt

Schmidt²,

Kelić³

et al. 2010

Phys. Rev. C

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“…The decay mechanism of hot nuclei heated by stopped and energetic antiprotons has been investigated with the facility of the low-energy antiproton ring (LEAR) at CERN [7][8][9][10][11]. Some interest findings were reported, e.g., the delayed fission by antiproton annihilation in heavy nuclei [12].…”

Section: Introductionmentioning

confidence: 99%

Nuclear fragmentation induced by low-energy antiprotons within a microscopic transport approach

Feng

2016

Phys. Rev. C

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Within the framework of the Lanzhou quantum molecular dynamics (LQMD) transport model, the nuclear fragmentation induced by low-energy antiprotons has been investigated thoroughly. A coalescence approach is developed for constructing the primary fragments in phase space. The secondary decay process of the fragments is described by the well-known statistical code. It is found that the localized energy released in antibaryon-baryon annihilation is deposited in a nucleus mainly via pion-nucleon collisions, which leads to the emissions of pre-equilibrium particles, fission, evaporation of nucleons and light fragments etc. The strangeness exchange reactions dominate the hyperon production. The averaged mass loss increases with the mass number of target nucleus. A bump structure in the domain of intermediate mass for heavy targets appears owing to the contribution of fission fragments. PACS number(s): 25.43.+t, 24.10.Lx, 25.70.Pq

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“…everal studies 1,2 in recent years have shown that "at rest" annihilation of antiprotons in the Uranium isotope U 238 leads to fission at nearly 100% efficiency. The resulting highly charged, fast fission fragments are highly ionizing, and can heat a suitable medium to very high temperatures.…”

Section: Introductionmentioning

confidence: 99%

Antimatter Induced Fission for Nuclear Rocket Propulsion

Kammash¹,

Tang²

2006

42nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference &Amp;amp; Exhibit

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A propulsion device in which antiprotons induced fission can be used to heat a suitable propellant to very high temperatures is presented. It is based on recent research which demonstrated that "at rest" annihilation of antiprotons in Uranium-238 nuclei induces fission at nearly 100% efficiency. The proposed device consists of an antiproton trap connected to a magnetic confinement system of the mirror configuration which will contain the pre-ionized propellant while being heated by the fission fragments and the annihilation products, namely the pions and muons. When an antiproton annihilates on a U 238 nucleus, fission fragments with a total mass of 212 amu and total energy of 160 MeV are ejected nearly isotropically and interact almost instantly with the electrons of the propellant plasma transferring energy to them. The electrons subsequently transfer energy to the ions, and this energy exchange time dictates the plasma confinement time in the mirror. We use a U 238 propellant since it is effectively hazardless, and can provide sizable thrust because of its massive nucleus. When heated to one keV temperature by the fission fragments and the annihilation products, it is shown that such a system is capable of producing about 3000 seconds of specific impulse at a thrust of about 48 kilo-Newtons. When applied to a round trip mission to Mars, it is shown that it can be accomplished in about 127 days consisting of 2.2 days of thrusting and the rest in coasting. It is also shown the trip would require one gram of antiprotons.

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Fission of heavy nuclei induced by stopped antiprotons. II. Correlations between fission fragments

Cited by 20 publications

References 15 publications

Fragmentation of spherical radioactive heavy nuclei as a novel probe of transient effects in fission

Fragmentation of spherical radioactive heavy nuclei as a novel probe of transient effects in fission

Nuclear fragmentation induced by low-energy antiprotons within a microscopic transport approach

Antimatter Induced Fission for Nuclear Rocket Propulsion

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