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Sample records for incomplete fusion reactions

  1. Incomplete fusion studies

    International Nuclear Information System (INIS)

    Singh, B.P.

    2011-01-01

    In order to study the incomplete fusion reaction dynamics at energies ≅ 4-7 MeV/nucleon, several experiments have been carried out using accelerator facilities available in India. The measurements presented here cover a wide range of projectile-target combinations and enhance significantly our knowledge about incomplete fusion reaction dynamics. Here, the three sets of measurements have been presented; (i) excitation functions, (ii) forward recoil range distributions and (iii) the spin distributions. The first evidence of these reactions has been obtained from the measurement and analysis of excitation functions for xn/αxn/2αxn-channels. The measured excitation functions have been analyzed within the framework of compound nucleus model. The results obtained indicate the occurrence of fusion incompleteness at low beam energies. However, in order to determine the relative contribution of complete and incomplete fusion reaction processes, the recoil range distributions of the heavy residues have also been measured and analyzed within the framework of breakup fusion model which confirmed the fusion incompleteness in several heavy ion reactions involving α-emitting reaction channels. Further, in order to study the role of l-values in these reactions the spin distributions of the residues populated in case of complete and incomplete channels have been measured and are found to be distinctly different. The analysis of the data on spin distribution measurements indicate that the mean values of driving input angular momenta associated with direct-α-emitting (incomplete fusion) channels are higher than that observed for fusion-evaporation xn or α-emitting (complete fusion) channels, and is found to increase with direct α-multiplicity in the forward cone. One of the important conclusions drawn in the present work is that, there is significant incomplete fusion contribution even at energies slightly above the barrier. Further, the projectile structure has been found to

  2. Effect of projectile structure on evaporation residue yields in incomplete fusion reactions

    CERN Document Server

    Babu, K S; Sudarshan, K; Shrivastava, B D; Goswami, A; Tomar, B S

    2003-01-01

    The excitation functions of heavy residues, representing complete and incomplete fusion products, produced in the reaction of sup 1 sup 2 C and sup 1 sup 3 C on sup 1 sup 8 sup 1 Ta have been measured over the projectile energy range of 5 to 6.5 MeV/nucleon by the recoil catcher method and off-line gamma-ray spectrometry. Comparison of the measured excitation functions with those calculated using the PACE2 code based on the statistical model revealed the occurrence of incomplete fusion reactions in the formation of alpha emission products. The fraction of incomplete fusion cross sections in the sup 1 sup 2 C + sup 1 sup 8 sup 1 Ta reaction was found to be higher, by a factor of approx 2, than that in the sup 1 sup 3 C + sup 1 sup 8 sup 1 Ta reaction. The results have been discussed in terms of the effect of alpha cluster structure of the projectile on incomplete fusion reactions.

  3. Effect of projectile on incomplete fusion reactions at low energies

    Directory of Open Access Journals (Sweden)

    Sharma Vijay R.

    2017-01-01

    Full Text Available Present work deals with the experimental studies of incomplete fusion reaction dynamics at energies as low as ≈ 4 - 7 MeV/A. Excitation functions populated via complete fusion and/or incomplete fusion processes in 12C+175Lu, and 13C+169Tm systems have been measured within the framework of PACE4 code. Data of excitation function measurements on comparison with different projectile-target combinations suggest the existence of ICF even at slightly above barrier energies where complete fusion (CF is supposed to be the sole contributor, and further demonstrates strong projectile structure dependence of ICF. The incomplete fusion strength functions for 12C+175Lu, and 13C+169Tm systems are analyzed as a function of various physical parameters at a constant vrel ≈ 0.053c. It has been found that one neutron (1n excess projectile 13C (as compared to 12C results in less incomplete fusion contribution due to its relatively large negative α-Q-value, hence, α Q-value seems to be a reliable parameter to understand the ICF dynamics at low energies. In order to explore the reaction modes on the basis of their entry state spin population, the spin distribution of residues populated via CF and/or ICF in 16O+159Tb system has been done using particle-γ coincidence technique. CF-α and ICF-α channels have been identified from backward (B and forward (F α-gated γspectra, respectively. Reaction dependent decay patterns have been observed in different α emitting channels. The CF channels are found to be fed over a broad spin range, however, ICF-α channels was observed only for high-spin states. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states

  4. Effect of projectile on incomplete fusion reactions at low energies

    Science.gov (United States)

    Sharma, Vijay R.; Shuaib, Mohd.; Yadav, Abhishek; Singh, Pushpendra P.; Sharma, Manoj K.; Kumar, R.; Singh, Devendra P.; Singh, B. P.; Muralithar, S.; Singh, R. P.; Bhowmik, R. K.; Prasad, R.

    2017-11-01

    Present work deals with the experimental studies of incomplete fusion reaction dynamics at energies as low as ≈ 4 - 7 MeV/A. Excitation functions populated via complete fusion and/or incomplete fusion processes in 12C+175Lu, and 13C+169Tm systems have been measured within the framework of PACE4 code. Data of excitation function measurements on comparison with different projectile-target combinations suggest the existence of ICF even at slightly above barrier energies where complete fusion (CF) is supposed to be the sole contributor, and further demonstrates strong projectile structure dependence of ICF. The incomplete fusion strength functions for 12C+175Lu, and 13C+169Tm systems are analyzed as a function of various physical parameters at a constant vrel ≈ 0.053c. It has been found that one neutron (1n) excess projectile 13C (as compared to 12C) results in less incomplete fusion contribution due to its relatively large negative α-Q-value, hence, α Q-value seems to be a reliable parameter to understand the ICF dynamics at low energies. In order to explore the reaction modes on the basis of their entry state spin population, the spin distribution of residues populated via CF and/or ICF in 16O+159Tb system has been done using particle-γ coincidence technique. CF-α and ICF-α channels have been identified from backward (B) and forward (F) α-gated γspectra, respectively. Reaction dependent decay patterns have been observed in different α emitting channels. The CF channels are found to be fed over a broad spin range, however, ICF-α channels was observed only for high-spin states. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states

  5. Spectroscopic study of 126I via incomplete fusion reaction

    International Nuclear Information System (INIS)

    Kanagalekar, B.A.; Das, Pragya; Kumar, Vinod; Kumar, R.; Singh, R.P.; Muralithar, S.; Bhowmik, R.K.

    2006-01-01

    The experiment at Inter University Accelerator Centre consisted of identifying the yrast high-spin states of 126 I using the incomplete fusion reaction 124 Sn ( 10 B, α4n) 126 I at beam energy of 70 MeV

  6. Decomposition of incomplete fusion

    International Nuclear Information System (INIS)

    Sobotka, L.B.; Sarantities, D.G.; Stracener, D.W.; Majka, Z.; Abenante, V.; Semkow, T.M.; Hensley, D.C.; Beene, J.R.; Halbert, M.L.

    1989-01-01

    The velocity distribution of fusion-like products formed in the reaction 701 MeV 28 Si+ 100 Mo is decomposed into 26 incomplete fusion channels. The momentum deficit of the residue per nonevaporative mass unit is approximately equal to the beam momentum per nucleon. The yields of the incomplete fusion channels correlate with the Q-value for projectile fragmentation rather than that for incomplete fusion. The backward angle multiplicities of light particles and heavy ions increase with momentum transfer, however, the heavy ion multiplicities also depend on the extent of the fragmentation of the incomplete fusion channel. These data indicate that at fixed linear momentum transfer, increased fragmentation of the unfused component is related to a reduced transferred angular momentum. 22 refs., 6 figs., 1 tab

  7. Incomplete fusion reactions in 16O+159Tb system: Spin distribution measurements

    Directory of Open Access Journals (Sweden)

    Sharma Vijay R.

    2015-01-01

    Full Text Available In order to explore the reaction modes on the basis of their entry state spin population, an experiment has been done by employing particle-γ coincidence technique carried out at the Inter University Accelerator Centre, New Delhi. The preliminary analysis conclusively demonstrates, spin distribution for some reaction products populated via complete and/or incomplete fusion of 16O with 159Tb system found to be distinctly different. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states.

  8. Low-energy nuclear reaction of the 14N+169Tm system: Incomplete fusion

    Science.gov (United States)

    Kumar, R.; Sharma, Vijay R.; Yadav, Abhishek; Singh, Pushpendra P.; Agarwal, Avinash; Appannababu, S.; Mukherjee, S.; Singh, B. P.; Ali, R.; Bhowmik, R. K.

    2017-11-01

    Excitation functions of reaction residues produced in the 14N+169Tm system have been measured to high precision at energies above the fusion barrier, ranging from 1.04 VB to 1.30 VB , and analyzed in the framework of the statistical model code pace4. Analysis of α -emitting channels points toward the onset of incomplete fusion even at slightly above-barrier energies where complete fusion is supposed to be one of the dominant processes. The onset and strength of incomplete fusion have been deduced and studied in terms of various entrance channel parameters. Present results together with the reanalysis of existing data for various projectile-target combinations conclusively suggest strong influence of projectile structure on the onset of incomplete fusion. Also, a strong dependence on the Coulomb effect (ZPZT) has been observed for the present system along with different projectile-target combinations available in the literature. It is concluded that the fraction of incomplete fusion linearly increases with ZPZT and is found to be more for larger ZPZT values, indicating significantly important linear systematics.

  9. Incomplete fusion reactions in Ho

    Indian Academy of Sciences (India)

    model [9], promptly emitted particles (PEPs) model [10], exciton model [11], etc. During the past decade a large number of reports have appeared [12–14] showing the occurrence of incomplete fusion at beam energy just above the Coulomb barrier. Recoil range distribution (RRD) measurements are particularly attractive for ...

  10. Competition between peripheral and central emission in incomplete fusion reactions

    International Nuclear Information System (INIS)

    Tricoire, H.

    1984-01-01

    In the frame of a classical model we show that the emission of fast particles in incomplete fusion reactions may occur either from a PEP emission which happens preferentially at low angular momenta or from an inertial emission with a maximum of the cross section located near the critical angular momentum for complete fusion. The competition of these mechanisms depends crucialy of the interaction between the particle to be emitted and the target nucleus. Numerical calculations are performed with various particle target potentials. Using a proximity potential, one gets results in good agreement with experimental data

  11. Investigation of the influence of incomplete fusion on complete fusion of {sup 12}C-induced reactions at {approx} 4-7.2 MeV/nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Amanuel, F.K. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova) (Italy); Zelalem, B.; Chaubey, A.K. [Addis Ababa University, Department of Physics, P.O.Box 1176, Addis Ababa (Ethiopia); Agarwal, Avinash [Bareilly College, Department of Physics, Bareilly (India); Rizvi, I.A.; Maheshwari, Anjana; Ahmed, Tauseef [Aligarh Muslim University, Department of Physics, Aligarh (India)

    2011-12-15

    In this paper, we present the results of our investigation of reaction dynamics leading to incomplete fusion of heavy ions at moderate excitation energies, especially the influence of incomplete fusion on complete fusion of {sup 12}C -induced reactions at specific energies {approx} 4-7.2M eV/nucleon. Excitation functions of various reaction products populated via complete and/or incomplete fusions of a {sup 12}C projectile with {sup 93}Nb, {sup 59}Co and {sup 52}Cr targets were measured at several specific energies {approx} 4-7.2 MeV/nucleon, using a recoil catcher technique, followed by off-line {gamma}-ray spectrometry. The measured excitation functions were compared with theoretical values obtained using the PACE4 statistical model code. For representative non-{alpha}-emitting channels in the {sup 12}C + {sup 93}Nb system, the experimentally measured excitation functions were, in general, found to be in good agreement with the theoretical predictions. However, for {alpha}-emitting channels in the {sup 12}C + {sup 93}Nb, {sup 12}C + {sup 59}Co, and {sup 12}C + {sup 52}Cr systems, the measured excitation functions were higher than the predictions of the theoretical model code, which may be credited to incomplete fusion reactions at these energies. An attempt was made to estimate the incomplete fusion fraction for the present systems, which revealed that the fraction was sensitive to the projectile energy and mass asymmetry of the entrance channel. (orig.)

  12. Light particle revelation on incomplete fusion reactions

    International Nuclear Information System (INIS)

    Gillibert, A.

    1984-01-01

    Incomplete fusion reactions have been studied through light particles emission in the reaction 116 Sn + 16 O at 125 MeV (ALICE facility in Orsay). We measured energy angular distributions and correlations between any two of these particles (α particles, protons, neutrons), while γ multiplicity measurements provide us fuller informations. From collected data, the following pictures can be drawn: - the only fast particles observed are α particles, while protons and neutrons seem to come only from statistical evaporation; - outgoing channels where two α particles are emitted cannot be solely explained by the sequential emission of 8 Be → 2α: about half of the cross section proceeds from statistical evaporation of one α particle. Accordingly, 2αxn channels do not necessarily agree with high value of angular momentum in the entrance channel. From the study of experimental results in the yrast plane, we can assign a large width to the angular momentum distribution [fr

  13. A dynamical theory of incomplete fusion reactions: The breakup-fusion reaction approach

    International Nuclear Information System (INIS)

    Udagawa, T.

    1984-01-01

    A dynamical theory of partial fusion reactions is presented, which may fill the gap between direct and compound nuclear reaction theories. With the new theory one can calculate partial fusion taking place in three-body (and many more) channels reached via direct reactions, e.g., breakup and knockout reactions. The authors present first the results for the cross section for such reactions, taking as an example breakup followed by fusion. They then discuss a physical picture which emerges from their theory, namely that the partial fusion reactions, particularly of the massive-transfer type, take place in a so-called deep peripheral region. It is also shown that the deep peripheral character of such processes diminishes as the mass of the fused system decreases, so that the reactions essentially evolve to the usual peripheral character. Finally, comparisons are made of results of numerical calculations with experimental data, taking as an example the /sup 159/Tb(/sup 14/N,α) reaction with E/sub lab/ = 95 MeV

  14. Study of incomplete fusion reaction dynamics in 13C +165 Ho system and its dependence on various entrance channel parameters

    Science.gov (United States)

    Tali, Suhail A.; Kumar, Harish; Ansari, M. Afzal; Ali, Asif; Singh, D.; Ali, Rahbar; Giri, Pankaj K.; Linda, Sneha B.; Parashari, Siddharth; Kumar, R.; Singh, R. P.; Muralithar, S.

    2018-02-01

    The excitation functions for the evaporation residues populated in the interaction of 13C +165 Ho system have been measured at projectile energies ≈ 4-7 MeV/nucleon. Stacked foil activation technique followed by off-line γ-ray spectroscopy have been employed in the present work. The experimentally measured cross-sections are analyzed in the frame work of statistical model code PACE4, which takes into account only the complete fusion reaction cross-sections. The evaporation residues populated via xn and pxn channels were found to be in good agreement with the PACE4 predictions, while a significant enhancement in the measured cross-sections over PACE4 predictions is observed in case of α-emitting channels, which may be attributed to the incomplete fusion process. For the better understanding of incomplete fusion dynamics, the incomplete fusion fraction has also been deduced and its sensitivity with various entrance channel parameters like: projectile energy, mass-asymmetry, projectile structure in terms of Qα-value and Coulomb effect has been studied in the present work. The incomplete fusion fraction is found to increase with increasing the projectile energy and a strong projectile structure dependent mass-asymmetry systematic is also observed. The incomplete fusion fraction is also found to be small for more negative Qα-value projectile (13C) induced reactions as compared to less negative Qα-value projectiles (12C, 16O and 20Ne) induced reactions with the same target nucleus 165Ho. An interesting trend is obtained on further investigation of incomplete fusion dependence on Coulomb effect (ZPZT).

  15. Spin distribution studies: a sensitive probe for in-complete fusion reaction dynamics

    International Nuclear Information System (INIS)

    Singh, Pushpendra P.; Singh, B.P.; Unnati; Sharma, Bhavna; Sharma, Manoj Kumar; Singh, D.; Afzal Ansari, M.; Prasad, R.; Rakesh Kumar; Golda, K.S.; Muralithar, S.; Singh, R.P.; Bhowmik, R.K.; Bhardwaj, H.D.

    2006-01-01

    With the view to get the conclusive information on critical angular momentum involvement for various degrees of incomplete fusion, an in-beam particle-gamma coincidence experiment has been performed in 16 O + 169 Tm system at ≅ 5.6 MeV/nucleon. Spin distributions for different reaction products have been measured by studying the relative population of different levels in a rotational band

  16. Absorption-Fluctuation Theorem for Nuclear Reactions: Brink-Axel, Incomplete Fusion and All That

    International Nuclear Information System (INIS)

    Hussein, M. S.

    2008-01-01

    We discuss the connection between absorption, averages and fluctuations in nuclear reactions. The fluctuations in the entrance channel result in the compound-nucleus Hauser-Feshbach cross section, and the fluctuations in the intermediate channels result in modifications of multistep reaction cross sections, while the fluctuations in the final channel result in hybrid cross sections that can be used to describe incomplete fusion reactions. We discuss the latter in detail and comment on the validity of the assumptions used in the development of the Surrogate method. We also discuss the theory of multistep reactions with regards to intermediate state fluctuations and the energy dependence and non-locality of the intermediate-channel optical potentials

  17. How does incomplete fusion show up at slightly above barrier energies?

    Directory of Open Access Journals (Sweden)

    Prasad R.

    2012-02-01

    Full Text Available Experimental results on the onset of incomplete fusion at slightly above barrier energies are discussed in this paper. Spin-distributions of evaporation residues populated via complete and/or incomplete fusion of 12C,16O (Elab ≈ 4–7 MeV with 169Tm have been measured to probe associated ℓ–values. Particle (Z=1,2 – γ – coincidence technique has been used for channel selection. Entirely different entry state spin populations have been observed during the de-excitation of complete and incomplete composites. The complete fusion residues are found to be strongly fed over a broad spin range. While, a narrow range feeding for only high spin states has been observed in case of incomplete fusion residues. In the present work, incomplete fusion is shown to be a promising tool to populate high spin states in final reaction products. For better insight into the onset and strength of incomplete fusion, the relative contributions of complete and incomplete fusion have been deduced from the analysis of excitation functions and forward recoil ranges. A significant fraction of ICF has been observed even at energy as low as ≈ 7% above the barrier. The relative strengths of complete and incomplete fusion deduced from the analysis of forward-recoil-ranges and excitation functions complement each other. All the available results are discussed in light of the Morgenstern’s mass-asymmetry systematics. Incomplete fusion fraction is found to be large for more mass-asymmetric systems for individual projectiles, which points towards the projectile structure effect on incomplete fusion fraction. Experimentally measured forward ranges of recoils complement the existence of incomplete fusion at slightly above barrier energies, where more than one linear-momentum-transfer components associated with full- and/or partial-fusion of projectile(s have been observed. Present results conclusively demonstrate the possibility to selectively populate high spin states

  18. Probing of complete and incomplete fusion dynamics in heavy-ion ...

    Indian Academy of Sciences (India)

    2014-04-04

    Apr 4, 2014 ... Heavy-ion induced reactions; complete and incomplete fusion; ... CF reaction the projectile completely fuses with the target nucleus and the highly excited .... input parameters have been used as default except the charge and ...

  19. Sensitivity of low-energy incomplete fusion to various entrance-channel parameters

    Science.gov (United States)

    Kumar, Harish; Tali, Suhail A.; Afzal Ansari, M.; Singh, D.; Ali, Rahbar; Kumar, Kamal; Sathik, N. P. M.; Ali, Asif; Parashari, Siddharth; Dubey, R.; Bala, Indu; Kumar, R.; Singh, R. P.; Muralithar, S.

    2018-03-01

    The disentangling of incomplete fusion dependence on various entrance channel parameters has been made from the forward recoil range distribution measurement for the 12C+175Lu system at ≈ 88 MeV energy. It gives the direct measure of full and/or partial linear momentum transfer from the projectile to the target nucleus. The comparison of observed recoil ranges with theoretical ranges calculated using the code SRIM infers the production of evaporation residues via complete and/or incomplete fusion process. Present results show that incomplete fusion process contributes significantly in the production of α xn and 2α xn emission channels. The deduced incomplete fusion probability (F_{ICF}) is compared with that obtained for systems available in the literature. An interesting behavior of F_{ICF} with ZP ZT is observed in the reinvestigation of incomplete fusion dependency with the Coulomb factor (ZPZT), contrary to the recent observations. The present results based on (ZPZT) are found in good agreement with recent observations of our group. A larger F_{ICF} value for 12C induced reactions is found than that for 13C, although both have the same ZPZT. A nonsystematic behavior of the incomplete fusion process with the target deformation parameter (β2) is observed, which is further correlated with a new parameter (ZP ZT . β2). The projectile α -Q-value is found to explain more clearly the discrepancy observed in incomplete fusion dependency with parameters ( ZPZT) and (ZP ZT . β2). It may be pointed out that any single entrance channel parameter (mass-asymmetry or (ZPZT) or β2 or projectile α-Q-value) may not be able to explain completely the incomplete fusion process.

  20. Extricate of incomplete fusion reactions at 4-7 MeV/A System:19F+159Tb

    International Nuclear Information System (INIS)

    Unnati; Mandal, S.K.; Yadav, A.; Singh, D.P.; Goswami, S.; Singh, B.P.; Sharma, M.K.

    2015-01-01

    Probing of heavy ion interactions and extricating of incomplete fusion (ICF) reactions at low energy regime is a topic of current interest. The main points of such studies is to explore the effect of various entrance channel parameters, viz., (i) the projectile energy, (ii) the mass asymmetry of interacting partners, and (iii) the input angular momenta imparted into the system. It is also pointed out that a separation of CF (Complete Fusion) from ICF is important for meaningful interpretation towards the splitting of nuclei. Further, considerable efforts are being employed to synthesize super heavy nuclei, the presence of various competing channels may add complexity to the synthesis of super heavy nuclei and obstruct the formation of such nuclei. Although, it is now possible to investigate reaction mechanism involved in formation of such nuclei but experimental studies are limited

  1. Complete and incomplete fusion dynamics of {sup 6,7}Li + {sup 159}Tb reactions near the Coulomb barrier

    Energy Technology Data Exchange (ETDEWEB)

    Gautam, Manjeet Singh [Thapar University, School of Physics and Materials Science, Patiala (India); Indus Degree College, Department of Physics, Kinana, Jind, Haryana (India); Grover, Neha; Sharma, Manoj K. [Thapar University, School of Physics and Materials Science, Patiala (India)

    2017-01-15

    The complete fusion (CF) and incomplete fusion (ICF) cross-sections are estimated for {sup 6,} {sup 7}Li + {sup 159}Tb reactions using the energy-dependent Woods-Saxon potential model (EDWSP model) and dynamical cluster-decay model (DCM). The CF data of the {sup 6}Li + {sup 159}Tb({sup 7}Li + {sup 159}Tb) reaction at above barrier energies is suppressed with reference to expectations of the EDWSP model by 25% (20%) which is smaller than the reported data by ∝ 9% (6%). This suppression is correlated with the projectile breakup effect. The projectiles {sup 6,7}Li are loosely bound systems, which may break up into charged fragments prior to reaching the fusion barrier and subsequently one of the fragment is captured by the target leading to the suppression of fusion data at above barrier energies. The sum of CF and ICF, which is termed as total fusion cross-section (TF), removes the discrepancies between theoretical predictions and the above barrier complete fusion data and hence is adequately explained via the EDWSP model over a wide range of energy spread across the Coulomb barrier. In addition to fusion, the decay mechanism of {sup 6}Li + {sup 159}Tb reaction is studied within the framework of the dynamical cluster-decay model (DCM). The breakup of the projectile ({sup 6}Li) in the entrance channel indicates the presence of ICF, which is investigated further using the collective clusterization approach of DCM. The present theoretical analysis suggests that a larger barrier modification is needed to address the fusion data of chosen reactions in the below barrier energy region. (orig.)

  2. $\\gamma$ -spectroscopy of n-rich $^{95,96}$Rb nuclei by the incomplete fusion reaction of $^{94}$Kr on $^{7}$Li

    CERN Multimedia

    We propose an experiment with MINIBALL coupled to T-REX to investigate n-rich $^{95,96}$Rb nuclei by the incomplete fusion reaction of $^{94}$Kr on $^{7}$Li. The nuclei of interest will be populated by transfer of a triton into $^{94}$Kr, forming the excited $^{97}$Rb nucleus, followed by the emission of an alpha particle, which will be detected in the Si telescopes of T-REX. The $^{97}$Rb product will evaporate 1 or 2 (with the highest probability) neutrons leading to $^{96}$Rb or $^{95}$Rb, respectively. The aim of the experiment is twofold: \\\\ i) to perform a $\\gamma$- spectroscopy study of $^{95,96}$Rb nuclei with N=58,59, the structure of which is of particular interest in investigating the transition towards stable deformation at N=60, \\\\ ii) to acquire experience in using incomplete fusion reactions with the weakly bound $^{7}$Li target, in order to perform, at a later stage with HIE-ISOLDE, similar measurements induced by n-rich radioactive beams of Sn and Hg, for which at least 5 MeV/nucleon are need...

  3. Incomplete fusion analysis of the 7Li-induced reaction on 93Nb within 3-6.5 MeV/nucleon

    Science.gov (United States)

    Kumar, Deepak; Maiti, Moumita

    2017-10-01

    Background: It is understood from the recent experimental studies that prompt/resonant breakup, and transfer followed by breakup in the weakly bound Li,76-induced reactions play a significant role in the complete-incomplete fusion (CF-ICF), suppression/enhancement in the fusion cross section around the Coulomb barrier. Purpose: Investigation of ICF over CF by measuring cross sections of the populated residues, produced via different channels in the 7Li-induced reaction on a natNb target within the 3-6.5 MeV/nucleon energy region. Method: The 7Li beam was allowed to hit the self-supporting 93Nb targets, backed by the aluminium (Al) foil alternately, within 3-6.5 MeV/nucleon energy. Populated residues were identified by offline γ -ray spectrometry. Measured excitation functions of different channels were compared with different equilibrium and pre-equilibrium models. Result: The enhancement in cross sections in the proton (˜20 -30 MeV) and α -emitting channels, which may be ascribed to ICF, was observed in the measured energy range when compared to the Hauser-Feshbach and exciton model calculations using empire, which satisfactorily reproduces the neutron channels, compared to the Weisskopf-Ewing model and hybrid Monte Carlo calculations. The increment of the incomplete fusion fraction was observed with rising projectile energy. Conclusion: Contrary to the alice14, experimental results are well reproduced by the empire throughout the measured energy range. The signature of ICF over CF indicates that the breakup/transfer processes are involved in the weakly bound 7Li-induced reaction on 93Nb slightly above the Coulomb barrier.

  4. Investigation of complete and incomplete fusion in 20Ne + 51V system using recoil range measurement

    Directory of Open Access Journals (Sweden)

    Ali Sabir

    2015-01-01

    Full Text Available Recoil range distributions of evaporation residues, populated in 20Ne + 51V reaction at Elab ≈ 145 MeV, have been studied to determine the degree of momentum transferred through the complete and incomplete fusion reactions. Evaporation residues (ERs populated through the complete and incomplete fusion reactions have been identified on the basis of their recoil range in the Al catcher medium. Measured recoil range of evaporation residues have been compared with the theoretical value calculated using the code SRIM. Range integrated cross section of observed ERs have been compared with the value predicted by statistical model code PACE4.

  5. Exploring incomplete fusion fraction in 6,7Li induced nuclear reactions

    Science.gov (United States)

    Parkar, V. V.; Jha, V.; Kailas, S.

    2017-11-01

    We have included breakup effects explicitly to simultaneously calculate the measured cross-sections of the complete fusion, incomplete fusion, and total fusion for 6,7Li projectiles on various targets using the Continuum Discretized Coupled Channels method. The breakup absorption cross-sections obtained with different choices of short range imaginary potentials are utilized to evaluate the individual α-capture and d/t-capture cross-sections and compare with the measured data. It is interesting to note, while in case of 7Li projectile the cross-sections for triton-ICF/triton-capture is far more dominant than α-ICF/α-capture at all energies, similar behavior is not observed in case of 6Li projectile for the deuteron-ICF/deuteron-capture and α-ICF/α-capture. Both these observations are also corroborated by the experimental data for all the systems studied.

  6. Exploring incomplete fusion fraction in 6,7Li induced nuclear reactions

    Directory of Open Access Journals (Sweden)

    Parkar V. V.

    2017-01-01

    Full Text Available We have included breakup effects explicitly to simultaneously calculate the measured cross-sections of the complete fusion, incomplete fusion, and total fusion for 6,7Li projectiles on various targets using the Continuum Discretized Coupled Channels method. The breakup absorption cross-sections obtained with different choices of short range imaginary potentials are utilized to evaluate the individual α-capture and d/t-capture cross-sections and compare with the measured data. It is interesting to note, while in case of 7Li projectile the cross-sections for triton-ICF/triton-capture is far more dominant than α-ICF/α-capture at all energies, similar behavior is not observed in case of 6Li projectile for the deuteron-ICF/deuteron-capture and α-ICF/α-capture. Both these observations are also corroborated by the experimental data for all the systems studied.

  7. Role of high l values in the onset of incomplete fusion

    International Nuclear Information System (INIS)

    Singh, Pushpendra P.; Yadav, Abhishek; Singh, Devendra P.; Gupta, Unnati; Singh, D.; Ansari, M. A.; Singh, B. P.; Prasad, R.; Sharma, Manoj K.; Kumar, R.; Singh, R. P.; Muralithar, S.; Bhowmik, R. K.

    2009-01-01

    A particle-γ-coincidence experiment is performed to investigate the role of high l values in the production of direct-α-emitting channels (associated with incomplete fusion) in 12 C+ 169 Tm system. Spin distributions of various xn/pxn/αxn/2αxn channels are measured at E lab =5.6A and 6.5A MeV. Entirely different de-excitation patterns are observed in direct-α-emitting channels and fusion-evaporation channels. The fusion-evaporation channels are found to be strongly fed over a broad spin range. While narrow range feeding for only high-spin states was observed in the case of direct-α-emitting channels, in the present work, incomplete fusion is shown to be a promising tool to populate high-spin states in final reaction products. To have better insight into the associated l values in different reaction channels, the present data are compared with similar data obtained in 16 O(E lab ≅5.6A MeV) + 169 Tm system. The mean driving angular momenta involved in the production of direct-α-emitting channels are found to be higher than those involved in the production of fusion-evaporation channels. Direct-α multiplicity in the forward cone increases with driving angular momenta, which indicates the origin of direct-α-emitting channels at high l values in noncentral interactions.

  8. Dynamics of complete and incomplete fusion in heavy ion collisions

    Science.gov (United States)

    Bao, Xiao Jun; Guo, Shu Qing; Zhang, Hong Fei; Li, Jun Qing

    2018-02-01

    In order to study the influence of the strong Coulomb and nuclear interactions on the dynamics of complete and incomplete fusion, we construct a new four-variable master equation (ME) so that the deformations as well as the nucleon transfer are viewed as consistently governed by MEs in the potential energy surface of the system. The calculated yields of quasifission fragments and evaporation residue cross section (ERCS) are in agreement with experimental data of hot fusion reactions. Comparing cross sections by theoretical results and experimental data, we find the improved dinuclear sysytem model also describes the transfer cross sections reasonably. The production cross sections of new neutron-rich isotopes are estimated by the multinucleon transfer reactions.

  9. Feeding intensity pattern in complete and incomplete fusion dynamics

    International Nuclear Information System (INIS)

    Linda, Sneha B.; Giri, Pankaj K.; Singh, D.; Kumar, Harish; Afzal Ansari, M.; Kumar, R.; Muralithar, S.; Singh, R.P.

    2017-01-01

    The heavy ion (HI) induced reactions has been a topic of special interest at energies above the Coulomb barrier. In these HI reactions, the most dominant modes are complete fusion (CF) and incomplete fusion (ICF) process. In ICF process, only a part of projectile fuses with the target nucleus, while remaining part of projectile moves in the forward cone. In the complete fusion (CF) process, the projectile is completely fused with the target nucleus, forming a highly excited composite system, which decays by evaporating low energy nuclear particles. To investigate the CF and ICF dynamics by measurement of spin distribution of ERs using 16 O projectile with 154 Sm target, an attempt has been made. The present particle-γ coincidence experiment have been performed using 15UD Pelletron Accelerator facility at Inter University Accelerator (IUAC), New Delhi, India. Gamma Detector Array (GDA) coupled with Charged Particle Detector Array (CPDA) experiment setup was used

  10. Disentangling effects of breakup coupling and incomplete fusion in 6Li + 232Th reaction

    International Nuclear Information System (INIS)

    Jha, V.; Parkar, V.V.; Mohanty, A.K.; Kailas, S.

    2014-01-01

    A component of fusion that is very important but quite difficult to evaluate is the incomplete fusion (ICF), in which only a part of the nucleus fuses with the target. ICF occurs together with the usual complete fusion (CF), in which the whole projectile fuses or all the projectile fragments after breakup fuse with the target nucleus. The ICF leads to the flux removal from the fusion channel and its calculation is essential for a comprehensive description of the fusion process. In the present work, a recently developed method of calculating the ICF cross-section (σ ICF ) is used in a novel way to disentangle the ICF effect on the fusion process from those due to breakup couplings. The total fusion cross-section σ TF and σ ICF for the 6 Li + 232 Th system are calculated at energies above and below the Coulomb barrier, where the measured fusion-fission data is available

  11. Reaction mechanisms in heavy ion fusion

    Directory of Open Access Journals (Sweden)

    Lubian J.

    2011-10-01

    Full Text Available We discuss the reaction mechanisms involved in heavy ion fusion. We begin with collisions of tightly bound systems, considering three energy regimes: energies above the Coulomb barrier, energies just below the barrier and deep sub-barrier energies. We show that channel coupling effects may influence the fusion process at above-barrier energies, increasing or reducing the cross section predicted by single barrier penetration model. Below the Coulomb barrier, it enhances the cross section, and this effect increases with the system’s size. It is argued that this behavior can be traced back to the increasing importance of Coulomb coupling with the charge of the collision partners. The sharp drop of the fusion cross section observed at deep sub-barrier energies is addressed and the theoretical approaches to this phenomenon are discussed. We then consider the reaction mechanisms involved in fusion reactions of weakly bound systems, paying particular attention to the calculations of complete and incomplete fusion available in the literature.

  12. Characterization of incomplete fusion in the reactions Ar + KCl at 32,40,52 and 74 MeV/u; Caracterisation de la fusion incomplete dans les reactions Ar + KCl a 32,40,52 et 74 Mev/u

    Energy Technology Data Exchange (ETDEWEB)

    Bisquer, E [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; [Universite Claude Bernard, 69 - Lyon (France)

    1996-12-20

    Heavy ion collisions at intermediate energies (10 to 100 A.MeV) have been investigated and gave evidence to the persistence of so-called low energy mechanisms such as incomplete fusion. This thesis aims at determining the energy threshold beyond which such a mechanism does not occur any more. First we investigated the so-called conventional incomplete fusion. This mechanism is well known from low energy studies: a thermalized compound nucleus is formed which further de-excites by evaporating particles. Residues will be therefore detected in coincidence with mainly light particles. Ar + KCl at incident energies of 32, 40, 52 and 74 A.MeV has been selected for this analysis. These experiments have been performed using the INDRA multidetector in GANIL (Caen). The detection performance of INDRA allowed to use new analysis methods via global variables. In a first step, global variables have been compared in order to find the one that is the most appropriate to our study. Then incomplete fusion events have been extracted from raw events recorded at incident energies of 32, 40 and 52 A.MeV. It turned out that the contribution of this mechanisms was very weak at 52. A.MeV. It turned out that the contribution of this mechanism was very weak at 52 A.MeV and even zero at 74 A.MeV. We then investigated events in which three fragments were detected which could possibly sign multifragmentation. We did not find instantaneous multifragmentation with any expansion contribution. We also performed BNV simulations in order to compare our experimental results to model predictions, solving in a semi-classical way the Vlasov transport equation. A good agreement has been obtained on the size of the compound nucleus formed. However the excitation energy has not been reproduced, as the code seems to overestimate the energy taken away by preequilibrium particles. Incomplete fusion decreases as a function of energy but is not replaced by instantaneous multifragmentation with any expansion

  13. Incomplete momentum transfer components in /sup 16/O + /sup 12/C Fusion at 20 MeV/A

    Energy Technology Data Exchange (ETDEWEB)

    Menchaca-Rocha, A.; Brandan, M.E. (Grenoble-1 Univ., 38 (France). Inst. des Sciences Nucleaires); Dacal, A.; Galindo, A.; Mahoney, J.; Murphy, M.; Rae, W.D.M. (California Univ., Berkeley (USA). Lawrence Berkeley Lab.)

    1983-01-27

    The energy spectra of Z = 3-9 particles from reactions induced by 20 MeV/A /sup 16/O on /sup 12/C have been measured. The systematics found from the fusion-like residues clearly deviate from those expected for complete fusion, giving evidence for important incomplete momentum transfer components.

  14. Measurement and analysis of excitation functions and observation of mass-asymmetry effect on incomplete fusion dynamics

    Directory of Open Access Journals (Sweden)

    Rashid M.H.

    2011-10-01

    Full Text Available Excitation functions for sixteen evaporation residues produced in the interaction of 20Ne with 165Ho have been measured in the projectile energy range ≈88-164 MeV, using catcher foil activation technique followed by gamma-ray spectrometry. It has been found in general that the excitation functions of evaporation residues produced via xn/pxn channels satisfactorily reproduced with the statistical model code PACE-2 after subtraction of precursor decay contribution. The significant enhancement in the measured excitation functions for the residues produced in alpha emission channels over the PACE-2 predictions has been observed. These alpha emission channels are attributed to incomplete fusion reaction process. The results indicate the occurrence of incomplete fusion involving break-up of projectile 20Ne into 4He + 16O and /or 8Be + 12C followed by fusion of one of the fragments with target nucleus 165Ho. The analysis of the present data suggest that probability of incomplete fusion increases with projectile energy. The ICF fraction FICF also increases with increasing mass-asymmetry of the entrance channel.

  15. In-complete fusion of 16O with 159Tb: measurement and analysis of excitation functions

    International Nuclear Information System (INIS)

    Singh, Pushpendra P.; Unnati; Sharma, Manoj Kumar; Singh, B.P.; Prasad, R.; Rakesh Kumar; Golda, K.S.; Bhardwaj, H.D.

    2006-01-01

    In order to have better understanding of incomplete fusion reaction dynamics, more experimental data covering a wide range of periodic table and energy are required. Cross-section data of such products are also in demand to determine the optimum irradiation conditions for the production of radioactive ion beams

  16. Observed side feeding in incomplete fusion dynamics in 16O + 160Gd reaction at energy ∼5.6 MeV/A: Spin distribution measurements

    Science.gov (United States)

    Ali, Rahbar; Afzal Ansari, M.; Singh, D.; Kumar, Rakesh; Singh, D. P.; Sharma, M. K.; Gupta, Unnati; Singh, B. P.; Shidling, P. D.; Negi, Dinesh; Muralithar, S.; Singh, R. P.; Bhowmik, R. K.

    2017-12-01

    Spin distributions of various residues populated via complete fusion (CF) and incomplete fusion (ICF) reactions in the interaction of 16O with 160Gd at the projectile energy Eproj ∼ 5.6 MeV/A have been studied. The experimentally measured spin distributions of the residues associated with the ICF reactions are found to be distinctly different from those populated via the CF reactions. An attempt has been made to extract the side-feeding pattern from the spin distributions of CF and ICF reaction products. It has been observed that the CF products are strongly fed over a broad spin range. But, no side-feeding takes place in the low observed spins as low partial waves are strongly hindered in the fast α-emission channels (associated with ICF) in the forward direction. It has also been observed that the mean input angular momentum for direct α-emitting (ICF) channels is relatively higher than evaporation α-emitting (CF) channels, and it increases with direct α-multiplicity in forward direction.

  17. Low energy incomplete fusion and its relevance to the synthesis of super heavy elements

    Directory of Open Access Journals (Sweden)

    Yadav Abhishek

    2015-01-01

    Full Text Available To study the presence of incomplete fusion at energies around the Coulomb-barrier and to understand its dependence on various entrance-channel parameters, the incomplete fusion fractions have been deduced (i from excitation function measurements for 18O,13,12C+159Tb, and (ii from forward recoil range measurements for 12C+159Tb systems, at low energies (<7MeV/A. The data have been analyzed within the framework of compound nucleus decay, which suggests the production of xn/pxn-channels via complete fusion, as these are found to be well reproduced by PACE4 predictions, while, a significant enhancement in the excitation functions of α-emitting channels has been observed over the theoretical ones, which has been attributed due to the incomplete fusion processes. Further, the incomplete fusion events observed in case of forward recoil ranges have been explained on the basis of the breakup fusion model, where these events may be attributed to the fusion of 8Be and/or 4He from 12C projectile to the target nucleus. For better insight into the underlying dynamics, the deduced fractions of incomplete fusion have been compared with other nearby systems as a function of various entrance channel parameters. The incomplete fusion has been found to be sensitive to the projectile’s energy and alpha-Q-value of the projectile.

  18. Disentangling complete and incomplete fusion for 9Be+187Re system at near barrier energies

    International Nuclear Information System (INIS)

    Kharab, Rajesh; Chahal, Rajiv; Rajiv Kumar

    2015-01-01

    The breakup of projectile before fusion leads to some unusual fusion mechanisms like incomplete fusion (ICF) and sequential complete fusion (SCF). Experimentally, it is not possible to separate SCF events from direct complete fusion (DCF). However, the complete fusion and incomplete fusion can be measured separately. Theoretically it is very difficult to calculate the complete and incomplete fusion cross section separately using different models. Very recently A. Diaz-Torres has developed a computer code platypus based on classical dynamical model wherein the complete and incomplete fusion cross sections are calculated separately. But this model is found to work very well at energies above the barrier energy. Here we have attempted to extrapolate the results of the code platypus by using simple Wong's formula in conjunction with the energy dependent Woods-Saxon potential (EDWSP) in the below barrier energy region

  19. Characterization of incomplete fusion in the reactions Ar + KCl at 32,40,52 and 74 MeV/u

    International Nuclear Information System (INIS)

    Bisquer, E.

    1996-01-01

    Heavy ion collisions at intermediate energies (10 to 100 A.MeV) have been investigated and gave evidence to the persistence of so-called low energy mechanisms such as incomplete fusion. This thesis aims at determining the energy threshold beyond which such a mechanism does not occur any more. First we investigated the so-called conventional incomplete fusion. This mechanism is well known from low energy studies: a thermalized compound nucleus is formed which further de-excites by evaporating particles. Residues will be therefore detected in coincidence with mainly light particles. Ar + KCl at incident energies of 32, 40, 52 and 74 A.MeV has been selected for this analysis. These experiments have been performed using the INDRA multidetector in GANIL (Caen). The detection performance of INDRA allowed to use new analysis methods via global variables. In a first step, global variables have been compared in order to find the one that is the most appropriate to our study. Then incomplete fusion events have been extracted from raw events recorded at incident energies of 32, 40 and 52 A.MeV. It turned out that the contribution of this mechanisms was very weak at 52. A.MeV. It turned out that the contribution of this mechanism was very weak at 52 A.MeV and even zero at 74 A.MeV. We then investigated events in which three fragments were detected which could possibly sign multifragmentation. We did not find instantaneous multifragmentation with any expansion contribution. We also performed BNV simulations in order to compare our experimental results to model predictions, solving in a semi-classical way the Vlasov transport equation. A good agreement has been obtained on the size of the compound nucleus formed. However the excitation energy has not been reproduced, as the code seems to overestimate the energy taken away by preequilibrium particles. Incomplete fusion decreases as a function of energy but is not replaced by instantaneous multifragmentation with any expansion

  20. Dynamics of complete and incomplete fusion of 6,7Li, 15N and 16O with a 209Bi target

    International Nuclear Information System (INIS)

    Gautam, Manjeet Singh; Vinod, K.; Khatri, Hitender

    2017-01-01

    The dynamics of complete and incomplete fusion of 6,7 Li, 15 N and 16 O with a common target ( 209 Bi) around the Coulomb barrier are analyzed within the context of the coupled channel formulation and the energy dependent Woods-Saxon potential (EDWSP) model. The calculated results are compared with experimental fusion cross-sections and it has been shown that complete fusion (CF) data of weakly bound projectile with a heavy target ( 209 Bi) gets suppressed at above barrier energies. In the case of the 6 Li + 209 Bi ( 7 Li + 209 Bi) reaction, the CF data at above barrier energies is reduced by 34% (26%) with reference to the expectations of the coupled channel approach. However, the theoretical estimations due to the EDWSP model can minimize the suppression factor by 9% with respect to the reported value and consequently the portion of above barrier CF cross-section data of 6 Li + 209 Bi ( 7 Li + 209 Bi) reaction is suppressed by 25% (17%) when compared with the present model calculations. This fusion inhibition can be correlated with the low breakup threshold of projectile which in turn breaks up into two fragments in the entrance channel prior to fusion barrier. The total fusion (TF) data, which is sum of complete fusion (CF) data and incomplete fusion (ICF) data, is not suppressed when compared with the predictions of the theoretical approaches and thus breakup channel has very little influence on the total fusion cross-sections. Although the breakup fragments appeared in both reactions, the enhanced suppression effects observed for the lighter projectile can be correlated with its low binding energy associated with the α-breakup channel. Further the outcomes of the EDWSP model reasonably explained the ICF contribution appeared in the fusion of 6,7 Li + 209 Bi reactions. In contrast to this, the observed fusion dynamics of 15 N + 209 Bi and 16 O + 209 Bi reactions, wherein the collective excitations such as two phonon, three phonon vibrational states contribute

  1. Recent developments in fusion and direct reactions with weakly bound nuclei

    International Nuclear Information System (INIS)

    Canto, L.F.; Gomes, P.R.S.; Donangelo, R.; Lubian, J.; Hussein, M.S.

    2015-01-01

    In this Report we give a balanced account of the experimental and theoretical advances acquired over the last decade in the field of near-barrier fusion reactions induced by weakly bound stable and unstable nuclei. The elastic scattering and breakup reactions of these systems are also extensively reviewed as they play an important role in the fusion process. We review several theoretical tools used in the description of the data. The concepts of Complete Fusion (CF), Incomplete Fusion (ICF) and Total Fusion (TF), which is the sum of CF and ICF, are discussed and recent work on the calculation of these quantities is reviewed. The Continuum Discretized Coupled Channels (CDCC) method and its semiclassical version are described in detail and their limitations are pointed out. More importantly, we describe the salient features of the conclusions reached from the more than 40 measurements made, over a decade, of near-barrier fusion, elastic scattering and breakup reactions, and confront these data with the CDCC or other methods appropriate for these processes at the energy regime in question.

  2. Spin distribution of evaporation residues formed in complete and incomplete fusion in 16O+154Sm system

    Science.gov (United States)

    Singh, D.; Linda, Sneha B.; Giri, Pankaj K.; Mahato, Amritraj; Tripathi, R.; Kumar, Harish; Afzal Ansari, M.; Sathik, N. P. M.; Ali, Rahbar; Kumar, Rakesh; Muralithar, S.; Singh, R. P.

    2017-11-01

    Spin distributions for several evaporation residues populated in the 16O+154Sm system have been measured at projectile energy ≈ 6.2 MeV/A by using the charged particle-γ-coincidence technique. The measured spin distributions of the evaporation residues populated through incomplete fusion associated with 'fast' α and 2α-emission channels are found to be entirely different from fusion-evaporation channels. It is observed that the mean input angular momentum for the evaporation residues formed in incomplete fusion channel is relatively higher than that observed for evaporation residues in complete fusion channels. The feeding intensity profile of evaporation residues populated through complete fusion and incomplete fusion have also been studied. The incomplete fusion channels are found to have narrow range feeding only for high spin states, while complete fusion channels are strongly fed over a broad spin range and widely populated. Comparison of present results with earlier data suggests that the mean input angular momentum values are relatively smaller for spherical target than that of deformed target using the same projectile and incident energy highlighting the role of target deformation in incomplete fusion dynamics.

  3. Spin distribution of evaporation residues formed in complete and incomplete fusion in 16O+154Sm system

    Directory of Open Access Journals (Sweden)

    D. Singh

    2017-11-01

    Full Text Available Spin distributions for several evaporation residues populated in the 16O+154Sm system have been measured at projectile energy ≈ 6.2 MeV/A by using the charged particle–γ-coincidence technique. The measured spin distributions of the evaporation residues populated through incomplete fusion associated with ‘fast’ α and 2α-emission channels are found to be entirely different from fusion–evaporation channels. It is observed that the mean input angular momentum for the evaporation residues formed in incomplete fusion channel is relatively higher than that observed for evaporation residues in complete fusion channels. The feeding intensity profile of evaporation residues populated through complete fusion and incomplete fusion have also been studied. The incomplete fusion channels are found to have narrow range feeding only for high spin states, while complete fusion channels are strongly fed over a broad spin range and widely populated. Comparison of present results with earlier data suggests that the mean input angular momentum values are relatively smaller for spherical target than that of deformed target using the same projectile and incident energy highlighting the role of target deformation in incomplete fusion dynamics.

  4. $\\gamma$- spectroscopy of n-rich $^{95,96}$Rb nuclei by the incomplete fusion reaction of $^{94}$Kr on $^{7}$Li: Introduction to HIE-ISOLDE studies of n-rich Sb and Tl isotopes with Sn and Hg radioactive beams.

    CERN Document Server

    Fornal, B; Bednarczyk, P; Cieplicka, N; Krolas, W; Maj, A; Leoni, S; Benzoni, G; Blasi, N; Bottoni, S; Bracco, A; Camera, F; Crespi, F; Million, B; Morales, A; Wieland, O; Rusek, K; Lunardi, S; Mengoni, D; Recchia, F; Ur, CA; Valiente-Dobon, J; de France, G; Clement, E; Elseviers, J; Flavigny, F; Huyse, M; Raabe, R; Sambi, S; Van Duppen, P; Sferrazza, M; Simpson, G; Georgiev, G; Sotty, C; Blazhev, A; German, R; Siebeck, B; Seidlitz, M; Reiter, P; Warr, N; Boenig, S; Ilieva, S; Kroell, T; Scheck, M; Thurauf, M; Gernhaeuser, R; Mucher, D; Janssens, R; Carpenter, MP; Zhu, S; Marginean, NM; Balabanski, D; Kowalska, M

    2012-01-01

    $\\gamma$- spectroscopy of n-rich $^{95,96}$Rb nuclei by the incomplete fusion reaction of $^{94}$Kr on $^{7}$Li: Introduction to HIE-ISOLDE studies of n-rich Sb and Tl isotopes with Sn and Hg radioactive beams.

  5. Energy dependence of fusion evaporation-residue cross sections in the 28Si+12C reaction

    International Nuclear Information System (INIS)

    Vineyard, M.F.; Mateja, J.F.; Beck, C.; Atencio, S.E.; Dennis, L.C.; Frawley, A.D.; Henderson, D.J.; Janssens, R.V.F.; Kemper, K.W.; Kovar, D.G.; Maguire, C.F.; Padalino, S.J.; Prosser, F.W.; Stephans, G.S.F.; Tiede, M.A.; Wilkins, B.D.; Zingarelli, R.A.

    1993-01-01

    Fusion evaporation-residue cross sections for the 28 Si+ 12 C reaction have been measured in the energy range 18≤E c.m. ≤136 MeV using time-of-flight techniques. Velocity distributions of mass-identified reaction products were used to identify evaporation residues and to determine the complete-fusion cross sections at high energies. The data are in agreement with previously established systematics which indicate an entrance-channel mass-asymmetry dependence of the incomplete-fusion evaporation-residue process. The complete-fusion evaporation-residue cross sections and the deduced critical angular momenta are compared with earlier measurements and the predictions of existing models

  6. Influence of the mass asymmetry on the incomplete fusion

    International Nuclear Information System (INIS)

    Singh, D.; Ali, R.; Pachouri, Dipti; Afzal Ansari, M.; Rashid, M.H.

    2007-01-01

    In the present work, a ratio of the incomplete fusion cross-section to the total cross-section (CF + ICF) has been measured, fraction for the 16 O + 45 Sc, 16 O + 74 Ge, 20 Ne + 59 Co and 20 Ne + 165 Ho systems at ≅ 3-8 MeV/ nucleon

  7. Dynamics of complete and incomplete fusion of {sup 6,7}Li, {sup 15}N and {sup 16}O with a {sup 209}Bi target

    Energy Technology Data Exchange (ETDEWEB)

    Gautam, Manjeet Singh; Vinod, K. [Indus Degree College, Department of Physics, Kinana, Jind, Haryana (India); Khatri, Hitender [Dr. B.R. Ambedekar Institute of Technology, Department of Physics, Port Blair, Andaman and Nicobar (India)

    2017-10-15

    The dynamics of complete and incomplete fusion of {sup 6,7}Li, {sup 15}N and {sup 16}O with a common target ({sup 209}Bi) around the Coulomb barrier are analyzed within the context of the coupled channel formulation and the energy dependent Woods-Saxon potential (EDWSP) model. The calculated results are compared with experimental fusion cross-sections and it has been shown that complete fusion (CF) data of weakly bound projectile with a heavy target ({sup 209}Bi) gets suppressed at above barrier energies. In the case of the {sup 6}Li + {sup 209}Bi ({sup 7}Li + {sup 209}Bi) reaction, the CF data at above barrier energies is reduced by 34% (26%) with reference to the expectations of the coupled channel approach. However, the theoretical estimations due to the EDWSP model can minimize the suppression factor by 9% with respect to the reported value and consequently the portion of above barrier CF cross-section data of {sup 6}Li + {sup 209}Bi ({sup 7}Li + {sup 209}Bi) reaction is suppressed by 25% (17%) when compared with the present model calculations. This fusion inhibition can be correlated with the low breakup threshold of projectile which in turn breaks up into two fragments in the entrance channel prior to fusion barrier. The total fusion (TF) data, which is sum of complete fusion (CF) data and incomplete fusion (ICF) data, is not suppressed when compared with the predictions of the theoretical approaches and thus breakup channel has very little influence on the total fusion cross-sections. Although the breakup fragments appeared in both reactions, the enhanced suppression effects observed for the lighter projectile can be correlated with its low binding energy associated with the α-breakup channel. Further the outcomes of the EDWSP model reasonably explained the ICF contribution appeared in the fusion of {sup 6,7}Li + {sup 209}Bi reactions. In contrast to this, the observed fusion dynamics of {sup 15}N + {sup 209}Bi and {sup 16}O + {sup 209}Bi reactions, wherein

  8. Fusion evaporation residues and the distribution of reaction strength in 16O + 40Ca and 28Si + 28Si reactions

    International Nuclear Information System (INIS)

    Kolata, J.J.; Hinnefeld, J.; Kovar, D.G.

    1985-01-01

    In measurements performed previously at ANL, studying the two entrance channels 16 O + 40 Ca and 28 Si + 28 Si which form the same compound nucleus 56 Ni, it was found that at higher bombarding energies (E/sub Lab/ > 5-7 MeV/nucleon) the distributions of reaction strength was dramatically different. Although the total reaction cross section behaviors for the two entrance channels are similar, the total evaporation residue (ER) cross sections for 28 Si + 28 Si decrease rapidly with increasing bombarding energies and up to the highest energy studied show no evidence for incomplete fusion processes. For 16 O + 40 Ca the ER cross section remains constant at approximately 1 barn with increasing bombarding energy and shows evidence of increasing contributions from incomplete fusion. To better understand this apparent dependence on the mass asymmetry in the entrance channel, coincidence measurements between evaporation residue-like products and heavy ions on the opposite side of the beam were performed for the two systems at E/sub Lab/ = 8 MeV/nucleon

  9. Energy dependence of fusion evaporation-residue cross sections in the 28Si+28Si reaction

    International Nuclear Information System (INIS)

    Vineyard, M.F.; Bauer, J.S.; Gosdin, C.H.; Trotter, R.S.; Kovar, D.G.; Beck, C.; Henderson, D.J.; Janssens, R.V.F.; Wilkins, B.D.; Rosner, G.; Chowdhury, P.; Ikezoe, H.; Kuhn, W.; Kolata, J.J.; Hinnefeld, J.D.; Maguire, C.F.; Mateja, J.F.; Prosser, F.W.; Stephans, G.S.F.

    1990-01-01

    Velocity distributions of mass-identified evaporation residues produced in the 28 Si+ 28 Si reaction have been measured at bombarding energies of 174, 215, 240, 309, 397, and 452 MeV using time-of-flight techniques. These distributions were used to identify evaporation residues and to separate the complete-fusion and incomplete-fusion components. Angular distributions and total cross sections were extracted at all six bombarding energies. The complete-fusion evaporation-residue cross sections and the deduced critical angular momenta are compared with lower energy data and the predictions of existing models

  10. Complete and incomplete fusion measurement and analysis of excitation functions in sup 1 sup 2 C + sup 1 sup 2 sup 8 Te system at energies near and above the coulomb barrier

    CERN Document Server

    Sharma, M K; Prasad, R; Gupta, S; Musthafa, M M; Bhardwaj, H D; Sinha, A K

    2003-01-01

    In order to study complete and incomplete fusion in heavy ion induced reactions the experiment has been carried out for measuring excitation functions (EF's) for several reactions in the system sup 1 sup 2 C + sup 1 sup 2 sup 8 Te, in the energy range approx = 42 - 82 MeV, using activation technique. To the best of our knowledge EF's for presently measured reactions are being reported for the first time. The measured EF's have been compared with those calculated theoretically using codes CASCADE and ALICE-91. Effect of variation of parameters, of the codes, on calculated EF's has also been studied. The analysis of the present data indicates presence of contributions from incomplete fusion in some cases. In general, theoretical calculations agree well with the experimental data.

  11. Measurement of inertial confinement fusion reaction rate

    International Nuclear Information System (INIS)

    Peng Xiaoshi; Wang Feng; Tang Daorun; Liu Shenye; Huang Tianxuan; Liu Yonggang; Xu Tao; Chen Ming; Mei Yu

    2011-01-01

    Fusion reaction rate is an important parameter for measuring compression during the implosion in inertial confinement fusion experiment. We have developed a system for fusion reaction history measurement with high temporal resolution. The system is composed of plastic scintillator and nose cone, optical system and streak camera. We have applied this system on the SG-III prototype for fusion reaction rate measuring. For the first time, fusion reaction rate history have been measured for deuterium-tritium filled targets with neutrons yields about 10 10 . We have analyzed possible influence factor during fusion reaction rate measuring. It indicates that the instrument measures fusion reaction bang time at temporal resolutions as low as 30 ps.(authors)

  12. Outline of cold nuclear fusion reaction

    International Nuclear Information System (INIS)

    Tachikawa, Enzo

    1991-01-01

    In 2010, as the total supply capacity of primary energy, 666 million liter is anticipated under the measures of thorough energy conservation. The development of energy sources along the energy policy based on environment preservation, safety, the quantity of resources and economy is strongly demanded. The nuclear power generation utilizing nuclear fission has been successfully carried out. As the third means of energy production, the basic research and technical development have been actively advanced on the energy production utilizing nuclear fusion reaction. The main object of the nuclear fusion research being advanced now is D-D reaction and D-T reaction. In order to realize low temperature nuclear fusion reaction, muon nuclear fusion has been studied so far. The cold nuclear fusion reaction by the electrolysis of heavy water has been reported in 1989, and its outline is ixplained in this report. The trend of the research on cold nuclear fusion is described. But the possibility of cold nuclear fusion as an energy source is almost denied. (K.I.)

  13. Influence of the mass asymmetry of the entrance channel on incomplete fusion processes

    International Nuclear Information System (INIS)

    Lleres, A.; Nifenecker, H.; Blachot, J.; Gizon, A.

    1989-05-01

    The angular and velocity distributions of incomplete fusion residues have been measured, around 30 AMeV projectile incident energy, for a number of systems with varying mass asymmetries, from the most asymmetric S+Cu, to the almost symmetric Ar+Ca. The main experimental finding is that the parallel width of the velocity distribution increases sharply for decreasing asymmetries, while the perpendicular width remains nearly constant. Using, as data, the widths and mean values of the velocity distributions, it was possible to derive the number of preequilibrium particles emitted by the projectile and by the target. It was found that target emission becomes noticeable only when the center of mass velocity of the target, at nuclear contact, exceeds approximately 2.5 cm/ns. This underlines the relevance of the center of mass velocities in the preequilibrium emission and incomplete fusion processes

  14. Fusion events

    International Nuclear Information System (INIS)

    Aboufirassi, M; Angelique, J.C.; Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Colin, J.; Cussol, D.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Kerambrun, A.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lefebvres, F.; Lopez, O.; Louvel, M.; Meslin, C.; Metivier, V.; Nakagawa, T.; Peter, J.; Popescu, R.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Wieloch, A.; Yuasa-Nakagawa, K.

    1998-01-01

    The fusion reactions between low energy heavy ions have a very high cross section. First measurements at energies around 30-40 MeV/nucleon indicated no residue of either complete or incomplete fusion, thus demonstrating the disappearance of this process. This is explained as being due to the high amount o energies transferred to the nucleus, what leads to its total dislocation in light fragments and particles. Exclusive analyses have permitted to mark clearly the presence of fusion processes in heavy systems at energies above 30-40 MeV/nucleon. Among the complete events of the Kr + Au reaction at 60 MeV/nucleon the majority correspond to binary collisions. Nevertheless, for the most considerable energy losses, a class of events do occur for which the detected fragments appears to be emitted from a unique source. These events correspond to an incomplete projectile-target fusion followed by a multifragmentation. Such events were singled out also in the reaction Xe + Sn at 50 MeV/nucleon. For the events in which the energy dissipation was maximal it was possible to isolate an isotropic group of events showing all the characteristics of fusion nuclei. The fusion is said to be incomplete as pre-equilibrium Z = 1 and Z = 2 particles are emitted. The cross section is of the order of 25 mb. Similar conclusions were drown for the systems 36 Ar + 27 Al and 64 Zn + nat Ti. A cross section value of ∼ 20 mb was determined at 55 MeV/nucleon in the first case, while the measurement of evaporation light residues in the last system gave an upper limit of 20-30 mb for the cross section at 50 MeV/nucleon

  15. Study of heavy ion fusion reaction of 58Ni + 24Mg at 11 MeV/nucleon

    International Nuclear Information System (INIS)

    Shea, J.Y.

    1991-01-01

    This thesis presents a study of the heavy ion fusion reaction in which a 58 Ni projectile bombards a 24 Mg target at 11 MeV/nucleon. The incident projectile energy was purposefully chosen so as the system studied to be at the onset of the more complex and interesting phenomenon of incomplete fusion. The physics motivation is to probe the central collision of a heavy, energetic, and asymmetric system by means of both inclusive and exclusive experimental measurements. The experiment was performed at HHIRF (Holifield Heavy Ion Research Facility) by using the coupled accelerators at Oak Ridge National Laboratory. The reaction products were measured by the new open-quotes HILI-Ringclose quotes large solid angle detector system at Oak Ridge National Laboratory. The thesis discusses the physics motivation and the systematics of heavy ion fusion reactions. Details of the design and construction of a new CsI(T1) Ring detector is given. Since this is the first such study performed on the Heavy Ion Light Ion (HILI) detector, an extensive discussion of the calibration procedures and the data reduction methods are given. The fusion reaction data were analyzed in both inclusive and exclusive modes with the result that a valuable new perspective on the deconvolution of the reaction mechanism has been achieved

  16. A light water excess heat reaction suggests that cold fusion may be alkali-hydrogen fusion

    International Nuclear Information System (INIS)

    Bush, R.T.

    1992-01-01

    This paper reports that Mills and Kneizys presented data in support of a light water excess heat reaction obtained with an electrolytic cell highly reminiscent of the Fleischmann-Pons cold fusion cell. The claim of Mills and Kneizys that their excess heat reaction can be explained on the basis of a novel chemistry, which supposedly also explains cold fusion, is rejected in favor of their reaction being, instead, a light water cold fusion reaction. It is the first known light water cold fusion reaction to exhibit excess heat, it may serve as a prototype to expand our understanding of cold fusion. From this new reactions are deduced, including those common to past cold fusion studies. This broader pattern of nuclear reactions is typically seen to involve a fusion of the nuclides of the alkali atoms with the simplest of the alkali-type nuclides, namely, protons, deuterons, and tritons. Thus, the term alkali-hydrogen fusion seems appropriate for this new type of reaction with three subclasses: alkali-hydrogen fusion, alkali-deuterium fusion, and alkali-tritium fusion. A new three-dimensional transmission resonance model (TRM) is sketched. Finally, preliminary experimental evidence in support of the hypothesis of a light water nuclear reaction and alkali-hydrogen fusion is reported. Evidence is presented that appears to strongly implicate the transmission resonance phenomenon of the new TRM

  17. Bilateral Complete and Incomplete Fusion of Incisors and its Management.

    Science.gov (United States)

    Da Costa, Godwin Clovis; Chalakkal, Paul; De Souza, Neil; Gavhane, Sanket

    2017-01-01

    This case report highlights the management of a case of bilateral complete and incomplete fusion of maxillary incisors in a 10-year-old child. A mock-up was done on the diagnostic cast. Pretreatment esthetic evaluation was done using bis-acryl composite temporaries which were transferred intraorally from the diagnostic cast using a putty index. An incisal overlap veneer preparation was done, following which, an IPS e-max veneer was cemented. A digital mock-up was carried out using the Adobe Photoshop and Corel Draw softwares to aid in laboratorial fabrication of the veneer.

  18. Systematic of fusion incompleteness in 20Ne induced reactions at energy 4-7 MeV/nucleon

    International Nuclear Information System (INIS)

    Ali, Sabir; Ahmad, Tauseef; Kumar, Kamal

    2016-01-01

    In the present work, a study of fusion incompleteness using the 20 Ne projectile over 51 V, 55 Mn and 59 Co and targets has been carried out. The experiment involving 20 N e+ 51 V system was performed at VECC, Kolkata, India. The targets of thickness range 1.19-1.50 rug/cm 2 of spectroscopically pure 51 V (purity 99.99%) were prepared by depositing on aluminum backing of thickness range 1.47-1.64 mg/cm 2 by the vacuum evaporation technique at the target lab of VECC. A stack of six 51 V targets was irradiated for ≈ 11 hrs by 20 Ne 6+ beam at ≈145 MeV. The irradiation of the stack covered the desired energy range of 82-145 MeV. The beam current was ≈ 40 nA during the irradiation hours. The energy of the 20 Ne ion beam incident on each target foil was calculated using stopping power software SRIM. The overall error in the present work is estimated to be ≤20%

  19. Influence of projectile α-breakup threshold on complete fusion

    International Nuclear Information System (INIS)

    Mukherjee, A.; Subinit Roy; Pradhan, M.K.; Saha Sarkar, M.; Basu, P.; Dasmahapatra, B.; Bhattacharya, T.; Bhattacharya, S.; Basu, S.K.; Chatterjee, A.; Tripathi, V.; Kailas, S.

    2006-01-01

    Complete fusion excitation functions for B11,10+Tb159 have been measured at energies around the respective Coulomb barriers, and the existing complete fusion measurements for Li7+Tb159 have been extended to higher energies. The measurements show significant reduction of complete fusion cross sections at above-barrier energies for both the reactions, B10+Tb159 and Li7+Tb159, when compared to those for B11+Tb159. The comparison shows that the extent of suppression of complete fusion cross sections is correlated with the α-separation energies of the projectiles. Also, the two reactions, B10+Tb159 and Li7+Tb159 were found to produce incomplete fusion products at energies near the respective Coulomb barriers, with the α-particle emitting channel being the favoured incomplete fusion process in both the cases

  20. An approach to understand incomplete fusion dynamics from recoil range distribution measurements

    International Nuclear Information System (INIS)

    Tali, Suhail A.; Kumar, Harish; Afzal Ansari, M.

    2016-01-01

    Britt and Quinton initially pointed out the incomplete fusion (ICF) signatures in the break-up of projectiles like 12 C, 14 N, and 16 O into α-clusters at ≈10 MeV/nucleon energies. Additional information was provided by Inamura et al. by performing the particle gamma coincidence experiment which significantly contributed in the understanding of ICF study. The interest to understand the ICF reaction dynamics for low Z projectiles (Z≤10) at energies ≈ 4-7MeV/nucleon has recently become an active area of research because of lack of any appropriate theoretical aspect, which may reproduce the experimental ICF data. At projectile energies above the Coulomb barrier, CF and ICF are dominant and competing reaction modes. For the imparted angular momentum ℓ < ℓ crit , the attractive nuclear potential is dominant, which may lead to the complete amalgamation of projectile with the target nucleus. However, for angular momentum ℓ> L crit , the projectile breaks into two parts one of them may fuse with the target nucleus, while the remainder moves as a spectator in forward direction with nearly the same velocity as that of incident projectile. The less excited composite system thus formed carries lower Forward Linear Momentum Transfer (FLMT) due to partial mass transferring from projectiles to the target nucleus compared to the compound nucleus formed via CF process

  1. Investigations of nuclear structure and nuclear reactions induced by complex projectiles

    International Nuclear Information System (INIS)

    Sarantites, D.G.

    1990-01-01

    This report discusses research in the following areas: nuclear structure; fusion reactions near and below the barrier; incomplete fusion and fragmentation reactions; and instrumentation and analysis. (LSP)

  2. Bilateral complete and incomplete fusion of incisors and its management

    Directory of Open Access Journals (Sweden)

    Godwin Clovis Da Costa

    2017-01-01

    Full Text Available This case report highlights the management of a case of bilateral complete and incomplete fusion of maxillary incisors in a 10-year-old child. A mock-up was done on the diagnostic cast. Pretreatment esthetic evaluation was done using bis-acryl composite temporaries which were transferred intraorally from the diagnostic cast using a putty index. An incisal overlap veneer preparation was done, following which, an IPS e-max veneer was cemented. A digital mock-up was carried out using the Adobe Photoshop and Corel Draw softwares to aid in laboratorial fabrication of the veneer.

  3. On fusion/fission chain reactions in the Fleischmann-Pons cold fusion experiment

    International Nuclear Information System (INIS)

    Anghaie, S.; Froelich, P.; Monkhorst, H.J.

    1990-01-01

    In this paper the possibility of fusion/fission chain reactions following d-d source reactions in electrochemical cold fusion experiments have been investigated. The recycling factors for the charged particles in fusion reactions with consumable nuclei deuteron, 6 Li nd 7 Li, are estimated. It is concluded that, based on the established nuclear fusion cross sections and electronic stopping power, the recycling factor is four to five orders of magnitude less than required for close to critical conditions. It is argued that the cross generation of charged particles by neutrons does not play a significant role in this process, even if increased densities at the surface of electrodes do occur

  4. Fusion hindrance in reactions with very heavy ions: Border between normal and hindered fusion

    International Nuclear Information System (INIS)

    Shen Caiwan; Li Qingfeng; Boilley, David; Shen Junjie; Abe, Yasuhisa

    2011-01-01

    The fusion hindrance in heavy-ion collisions is studied in the framework of the two-center liquid drop model. It appears that the neck and the radial degrees of freedom might both be hampered by an inner potential barrier on their path between the contact configuration to the compound nucleus. Heavy-ion reactions with and without the two kinds of fusion hindrance are classified through systematic calculations. It is found that the number of reactions without radial fusion hindrance is much smaller than that without neck fusion hindrance, and for both kinds of fusion hindrance the number of reactions without fusion hindrance at small mass-asymmetry parameter α is smaller than that at large α. In the formation of a given compound nucleus, if a reaction with α c is not hindered, then other reactions with α>α c are also not hindered, as is well known experimentally.

  5. Proceedings of the symposium on the many facets of heavy ion fusion reactions

    International Nuclear Information System (INIS)

    1986-01-01

    The topics of the symposium are sub- and near-barrier fusion, limitations to fusion, compound nucleus decay and spectroscopy, incomplete fusion processes, and fragmentation and liquid-gas phase transition. Separate abstracts were prepared for 54 papers in these proceedings

  6. Fusion chain reaction - a chain reaction with charged particles

    International Nuclear Information System (INIS)

    Peres, A.; Shvarts, D.

    1975-01-01

    When a DT-plasma is compressed to very high density, the particles resulting from nuclear reactions give their energy mostly to D and T ions, by nuclear collisions, rather than to electrons as usual. Fusion can thus proceed as a chain reaction, without the need of thermonuclear temperatures. In this paper, we derive relations for the suprathermal ion population created by a fusion reaction. Numerical integration of these equations shows that a chain reaction can proceed in a cold infinite DT-plasma at densities above 8.4x10 27 ions.cm -3 . Seeding the plasma with a small amount of 6 Li reduces the critical density to 7.2x10 27 ions.cm -3 (140000times the normal solid density). (author)

  7. Verification of cold nuclear fusion reaction, (1)

    International Nuclear Information System (INIS)

    Yoshida, Zenko; Aratono, Yasuyuki; Hirabayashi, Takakuni

    1991-01-01

    Can cold nuclear fusion reaction occur as is expected? If it occurs, what extent is its reaction probability? At present after 2 years elapsed since its beginning, the clear solution of these questions is not yet obtained. In many reaction systems employing different means, the experiments to confirm the cold nuclear fusion reaction have been attempted. In order to confirm that the nuclear fusion reaction of deuterium mutually has occurred, the neutrons, He-3, protons, tritium or generated heat, which were formed by the reaction and released from the system, are measured. Since it is considered that the frequency of the occurrence at normal temperature of the reaction is very low, it is necessary to select the most suitable method upon evaluating the limit of detection peculiar to the measuring methods. The methods of measuring neutrons, protons, gamma ray and generated heat, and the reaction systems by electrolytic process and dry process are explained. The detection of plural kinds of the reaction products and the confirmation of synchronism of signals are important. (K.I.)

  8. An incomplete assembly with thresholding algorithm for systems of reaction-diffusion equations in three space dimensions IAT for reaction-diffusion systems

    International Nuclear Information System (INIS)

    Moore, Peter K.

    2003-01-01

    Solving systems of reaction-diffusion equations in three space dimensions can be prohibitively expensive both in terms of storage and CPU time. Herein, I present a new incomplete assembly procedure that is designed to reduce storage requirements. Incomplete assembly is analogous to incomplete factorization in that only a fixed number of nonzero entries are stored per row and a drop tolerance is used to discard small values. The algorithm is incorporated in a finite element method-of-lines code and tested on a set of reaction-diffusion systems. The effect of incomplete assembly on CPU time and storage and on the performance of the temporal integrator DASPK, algebraic solver GMRES and preconditioner ILUT is studied

  9. Fusion and reactions of exotic nuclei

    Directory of Open Access Journals (Sweden)

    Sánchez-Benítez A.M.

    2011-10-01

    Full Text Available Close to the drip lines, the scattering cross sections of halo nuclei show a different behaviour as compared to the tightly bound projectiles of the stability line. Several experiments carried out in the last decade have been dedicated to investigate the competition between transfer, breakup and fusion channels at energies around and below the Coulomb barrier. The rather complex scenario gives rise to conflicting conclusions concerning the effect of breakup and transfer on reaction dynamics and the sub-barrier fusion process. In this work we discuss recent experimental findings in fusion and reactions of 6He halo nucleus at energies around the Coulomb barrier.

  10. Fusion enhancement in the reactions of neutron-rich nuclei

    International Nuclear Information System (INIS)

    Bian Baoan; Zhang Fengshou; Zhou Hongyu

    2009-01-01

    The neutron-rich fusion reactions are investigated systematically using the improved isospin dependent quantum molecular dynamics model. By studying the systematic dependence of fusion barrier on neuron excess, we find the enhancement of the fusion cross sections for neutron-rich nuclear reactions that give the lowered static Coulomb barriers. The calculated fusion cross sections agree quantitatively with the experimental data. We further discuss the mechanism of the fusion enhancement of the cross sections for neutron-rich nuclear reactions by analyzing the dynamical lowering of the Coulomb barrier that is attributed to the enhancement of the N/Z ratio at the neck region.

  11. Applications of Skyrme energy-density functional to fusion reactions spanning the fusion barriers

    International Nuclear Information System (INIS)

    Liu Min; Wang, Ning; Li Zhuxia; Wu Xizhen; Zhao Enguang

    2006-01-01

    The Skyrme energy density functional has been applied to the study of heavy-ion fusion reactions. The barriers for fusion reactions are calculated by the Skyrme energy density functional with proton and neutron density distributions determined by using restricted density variational (RDV) method within the same energy density functional together with semi-classical approach known as the extended semi-classical Thomas-Fermi method. Based on the fusion barrier obtained, we propose a parametrization of the empirical barrier distribution to take into account the multi-dimensional character of real barrier and then apply it to calculate the fusion excitation functions in terms of barrier penetration concept. A large number of measured fusion excitation functions spanning the fusion barriers can be reproduced well. The competition between suppression and enhancement effects on sub-barrier fusion caused by neutron-shell-closure and excess neutron effects is studied

  12. Fusion of multiagent preference orderings with information on agent's importance being incomplete certain

    Institute of Scientific and Technical Information of China (English)

    Wang Jianqiang

    2007-01-01

    The problem of fusing multiagent preference orderings, with information on agent's importance being incomplete certain with respect to a set of possible courses of action, is described. The approach is developed for dealing with the fusion problem described in the following sections and requires that each agent provides a preference ordering over the different alternatives completely independent of the other agents, and the information on agent's importance is incomplete certain. In this approach, the ternary comparison matrix of the alternatives is constructed, the eigenvector associated with the maximum eigenvalue of the ternary comparison matrix is attained so as to normalize priority vector of the alternatives. The interval number of the alternatives is then obtained by solving two sorts of linear programming problems. By comparing the interval numbers of the alternatives, the ranking of alternatives can be generated. Finally, some examples are given to show the feasibility and effectiveness of the method.

  13. Excitation functions for some Ne induced reactions with Holmium: incomplete fusion vs complete fusion

    International Nuclear Information System (INIS)

    Agarwal, Avinash; Kumar, Munish; Sharma, Anjali; Rizvi, I.A.; Ahamad, Tauseef; Ghugre, S.S.; Sinha, A.K.; Chaubey, A.K.

    2010-01-01

    Reactions induced by 20 Ne are expected to be considerably more complex than those of 12 C, and 16 O. As a part of the ongoing program to understand CF and ICF reaction mechanisms, it is of great interest to see whether the same experimental technique yield similarly valuable information for 20 Ne induced reactions. In this present work an attempt has been made to measure the excitation functions for fifteen evaporation residues (ERs) identified in the interaction of 20 Ne + 165 Ho system in the energy range 4 -7 MeV/A

  14. The role of chain carriers in fusion reaction kinetics

    International Nuclear Information System (INIS)

    Harms, A.A.; Krenciglowa, E.M.

    1980-01-01

    The role of chain carriers as contributors to multiplicative closed cycles in advanced fusion fuels is examined. Emphasis is placed on rate processes which can be used to characterize critical/supercritical/subcritical tendencies of arbitrary closed fusion cycles. Temporal trajectories for the chain carriers which describe both increasing and decreasing multiplicative processes have been found to exist and identified according to their fusion fuel cycle characteristics. Practical criteria to ensure the attainment of steady-state fusion reaction processes have been formulated in terms of fusion reaction rate relationships. (author)

  15. Fusion reaction using low energy neutron-excess nucleus beam

    International Nuclear Information System (INIS)

    Fukuda, Tomokazu

    1994-01-01

    The present state and the plan of the experiment of measuring the fusion reaction near barriers by using neutron-excess nucleus beam, which has been advanced at RIKEN are reported. One of the purposes of this experiment is the feasibility investigation of the fusion reaction by using neutron-excess nuclei, which is indispensable for synthesizing superheavy elements. It is intended to systematically explore some enhancing mechanism in the neutron-excess nuclei which are unfavorable in beam intensity. This research can become the good means to prove the dynamic behavior of the neutrons on the surfaces of nuclei in reaction. The fusion reaction of 27 Al + Au was measured by using the stable nucleus beam of 27 Al, and the results are shown. In order to know the low energy fusion reaction of 11 Li and 11 Be which are typical halo nuclei, the identification by characteristic α ray of composite nuclei is carried out in 7,9,11 Li + 209 Bi and 9,10,11 Be + 208 Pb. A new detector having high performance, New MUSIC, is being developed. As the experiment by using this detector, the efficient measurement of the fusion reaction by using heavy neutron-excess nuclei up to Ni is considered. An example of 8 Li + α → 11 B + n reaction for celestial body physics is mentioned. (K.I.)

  16. Cold fusion in symmetric 90Zr induced reactions

    International Nuclear Information System (INIS)

    Keller, J.G.

    1985-02-01

    At the velocity filter SHIP of the Society for Heavy Ion Research in Darmstadt cross sections for evaporation-residue-nucleus formation in the reactions 90 Zr+ 89 Y, sup(90,92,96)Zr, 94 Mo were measured. In four of the reactions leading to the compound nuclei 179 Au, 180 Hg, 182 Hg, and 184 Pb for the first time in reactions of two heavy partners with mass numbers >20 radiative capture, i.e. deexcitation only by emission of γ radiation, was observed. A comparison of the measured cross sections for radiative capture with evaporation calculations leads to the final conclusion that either the γ-strength in the different compound nuclei is very different, or that the energy or angular momentum dependence of the level-density is wrongly described by the Fermi gas model at energies between 5 and 20 MeV. From the cross sections for evaporation-residue-nucleus formation fusion probabilities for central collisions were derived. The fusion probabilities show a strong dependence of the sub-barrier fusion from the nuclear structure of the contributing reaction partners. The slope of the fusion probability below the classical fusion barrier cannot be consistently described even by newer models. Below the lowest fusion barrier the fusion probability decreases with decreasing energy remarkably faster that predicted by a WKB calculation. This indicates that either the shape of the barrier is different from that predicted by the potentials, or that the mass dependence of the tunnel effect is not correctly described by the WKB calculation. (orig.) [de

  17. How does the carbon fusion reaction happen in stars?

    International Nuclear Information System (INIS)

    Tang, X.; Bucher, B.; Fang, X.; Notani, M.; Tan, W.P.; Mooney, P.; Li, Y.; Esbensen, H.; Jiang, C.L.; Rehm, K.E.; Lin, C.J; Brown, E.

    2012-01-01

    The 12 C + 12 C fusion reaction is one of the most important reactions in the stellar evolution. Due to its complicated reaction mechanism, there is great uncertainty in the reaction rate which limits our understanding of various stellar objects, such as massive stellar evolution, explosions on neutron stars, and supernovae from accreting white dwarf stars. In this paper, I will review the challenges in the study of carbon burning. I will also report recent results from our studies: 1) an upper limit for the 12 C + 12 C fusion cross sections, 2) measurement of the 12 C + 12 C at deep sub-barrier energies, and 3) a new measurement of the 12 C( 12 C, n) reaction. The outlook for the studies of the astrophysical heavy-ion fusion reactions will also be presented

  18. Small suppression of the complete fusion of {sup 6}Li + {sup 28}Si reaction at near barrier energies

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Mandira [Bose Institute, Department of Physics, Kolkata (India); Lubian, J. [Universidade Federal Fluminense, Instituto de Fisica, Niteroi, Rio de Janeiro (Brazil)

    2017-11-15

    The incomplete fusion cross section of the {sup 6}Li + {sup 28}Si weakly bound system at above barrier energies was deduced from the measured γ-ray cross sections. The complete fusion cross section was estimated from the measured total fusion and incomplete fusion cross section and is found to be 85-100% of the total fusion cross section. The coupled channel calculation has been performed considering ground and first excited states of {sup 28}Si target. The fusion cross section estimated from coupled channel calculation shows good agreement with measured total fusion cross section at higher energies. The suppression of about 15% of the fusion cross section predicted by coupled channel calculation shows good agreement with the complete fusion cross section. The effect of the channel couplings on the elastic scattering angular distribution is also investigated. (orig.)

  19. Fusion Reactions and Matter-Antimatter Annihilation for Space Propulsion

    Science.gov (United States)

    2005-07-13

    FUSION REACTIONS AND MATTER- ANTIMATTER ANNIHILATION FOR SPACE PROPULSION Claude DEUTSCH LPGP (UMR-CNRS 8578), Bât. 210, UPS, 91405 Orsay...REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE šFusion Reactions And Matter- Antimatter Annihilation For Space Propulsion 5a...which is possible with successful MCF or ICF. Appropriate vessel designs will be presented for fusion as well as for antimatter propulsion. In

  20. Study of fusion reactions forming Cf nuclei

    International Nuclear Information System (INIS)

    Khuyagbaatar, J.; Hinde, D. J.; Du Rietz, R.; Carter, I. P.; Dasgupta, M.; Duellmann, C. E.; Evers, M.; Wakhle, A.; Williams, E.; Yakushev, A.

    2013-01-01

    The formation of a compound nucleus in different projectile and target combinations is a powerful method for investigating the fusion process. Recently, the dominance of quasi-fission over fusion-fission has been inferred for 34 S+ 208 Pb in comparison to 36 S+ 206 Pb; both reactions lead to the compound nucleus 242 Cf*.The mass and angle distributions of the fission fragments from these reactions were studied in order to further investigate the presence of quasi-fission. (authors)

  1. How does the carbon fusion reaction happen in stars?

    Directory of Open Access Journals (Sweden)

    X. Tang

    2013-09-01

    Full Text Available The 12C + 12C fusion reaction is one of the most important reactions in the stellar evolution. Due to its compli-cated reaction mechanism, there is great uncertainty in the reaction rate which limits our understanding of vari-ous stellar objects, such as explosions on the surface of neutron stars, white dwarf (type Ia supernovae, and massive stellar evolution. In this paper, I will review the challenges in the study of carbon burning. I will also report recent re-sults from our studies: 1 an upper limit for the 12C + 12C fusion cross sections, 2 measurement of the 12C + 12C at deep sub-barrier energies, 3 a new measurement of the 12C(12C, n reaction. The outlook for the studies of the astrophysical heavy-ion fusion reactions will also be presented.

  2. Subsequent development of the normal temperature fusion reaction. Joon kakuyugo sonogo no shinten

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, T. (Hokkaido University, Sapporo (Japan). Faculty of Engineering)

    1991-04-24

    This paper reports on a NATTOH model made public in May 1989 by T. Matsumoto who took notice of abnormality of the normal temperature fusion reaction. The NATTO model is based on a chain reaction by hydrogen with a hydrogen-catalyzed fusion reaction which is the normal temperature fusion reaction as an elementary process. If a high temperature fusion reaction is a small-size simulation of the fusion reaction rising on the surface of the sparkling star like the sun, the normal temperature fusion reaction can be a small-size simulation of the phenomena in the last years of the star in the far distance of the space. This gives reality to the normal temperature fusion reaction. The reaction mechanism of the normal temperature fusion reaction is almost being clarified by a NATTOH model. There remain problems on a possibility of generation of unknown radioactive rays and identification of radioactive wastes, but it seems that a prospect of commercialization can be talked about now. As for the utilization as energy, sea water may be used as it is. 10 ref., 5 figs.

  3. Measurement of nuclear potentials from fusion excitation functions

    International Nuclear Information System (INIS)

    Huizenga, J.R.; Birkelund, J.R.

    1984-01-01

    The basis for measuring nuclear potentials from fusion excitation functions at energies above barrier is reviewed. It is argued that because of experimental and conceptual problems fusion excitation functions at high energies cannot lead to model independent measurements of internuclear potential at small separations. The Al 27 + Ne 20 reaction previously analyzed by others is used as an example of problems arising from the inability to distinguish complete and incomplete fusion in experimental data

  4. Neutron detector for fusion reaction-rate measurements

    International Nuclear Information System (INIS)

    Lerche, R.A.; Phillion, D.W.; Tietbohl, G.L.

    1993-01-01

    We have developed a fast, sensitive neutron detector for recording the fusion reaction-rate history of inertial-confinement fusion (ICF) experiments. The detector is based on the fast rise-time of a commercial plastic scintillator (BC-422) and has a response 7 neutrons

  5. Selected aspects of fusion reactions

    International Nuclear Information System (INIS)

    Lacroix, D.

    2003-01-01

    In this lecture, we present selected aspects of nuclear fusion. The importance of the initial geometry of the reaction and its relation to fusion barrier are first discussed. The effect of deformation leading to the notion of barrier distribution is then illustrated. After a brief overview of the advantages of macroscopic theories, the dynamics of nuclear system under large amplitude motion is reviewed. The di-nuclear concept is presented to understand the competition between fusion and quasi-fission. This concept is then generalized to account for the dissipative dynamics in multidimensional collective space. The last part of this lecture is devoted to new aspects encountered with radioactive beams specific properties of very extended neutron rich system, influence of pygmy or soft dipole resonances and charge exchange far from stability are discussed. (author)

  6. Fusion reaction product diagnostics in ASDEX

    International Nuclear Information System (INIS)

    Bosch, H.S.

    1987-01-01

    A diagnostic method was developed to look for the charged fusion products from the D(D,p)T-reactions in the divertor tokamak ASDEX. With a semi-conductor detector it was possible to evaluate the ion temperature in thermal plasmas from the proton energy spectra as well as from the triton spectra. In lower-hybrid wave heated plasmas non-thermal (fast) ions were observed. These ions create fusion products with a characteristically different energy spectrum. (orig.)

  7. Effects of reaction channels in subbarrier fusion reactions

    International Nuclear Information System (INIS)

    Dasso, C.H.

    1984-01-01

    In this lecture we consider some aspects of fusion reactions between heavy ions at bombarding energies which are below or close to that of the Coulomb barrier. This problem has been traditionally confronted with simple barrier penetration calculations. So we start with a very brief review of what we can call the ''conventional'' procedure. (orig.)

  8. Screening effects on 12C+12C fusion reaction

    Science.gov (United States)

    Koyuncu, F.; Soylu, A.

    2018-05-01

    One of the important reactions for nucleosynthesis in the carbon burning phase in high-mass stars is the 12C+12C fusion reaction. In this study, we investigate the influences of the nuclear potentials and screening effect on astrophysically interesting 12C+12C fusion reaction observables at sub-barrier energies by using the microscopic α–α double folding cluster (DFC) potential and the proximity potential. In order to model the screening effects on the experimental data, a more general exponential cosine screened Coulomb (MGECSC) potential including Debye and quantum plasma cases has been considered in the calculations for the 12C+12C fusion reaction. In the calculations of the reaction observables, the semi-classical Wentzel-Kramers-Brillouin (WKB) approach and coupled channel (CC) formalism have been used. Moreover, in order to investigate how the potentials between 12C nuclei produce molecular cluster states of 24Mg, the normalized resonant energy states of 24Mg cluster bands have been calculated for the DFC potential. By analyzing the results produced from the fusion of 12C+12C, it is found that taking into account the screening effects in terms of MGECSC is important for explaining the 12C+12C fusion data, and the microscopic DFC potential is better than the proximity potential in explaining the experimental data, also considering that clustering is dominant for the structure of the 24Mg nucleus. Supported by the Turkish Science and Research Council (TÜBİTAK) with (117R015)

  9. A view on reactions of complete fusion

    International Nuclear Information System (INIS)

    Delchev, I.I.; Petkov, I.J.

    1978-11-01

    Complete fusion reactions are analysed within the framework of a theoretical model. Energy density interaction potentials are made use of and are renormalized for the purpose. A large number of heavy ion reactions are studied and the calculated critical angular moments are compared with experimental data

  10. Design of a fusion reaction-history measurement system with high temporal resolution

    International Nuclear Information System (INIS)

    Peng Xiaoshi; Wang Feng; Liu Shenye; Jiang Xiaohua; Tang Qi

    2010-01-01

    In order to accurately measure the history of fusion reaction for experimental study of inertial confinement fusion, we advance the design of a fusion reaction-history measurement system with high temporal resolution. The diagnostic system is composed of plastic scintillator and nose cone, an optical imaging system and the system of optic streak camera. Analyzing the capability of the system indicated that the instrument measured fusion reaction history at temporal resolution as low as 55ps and 40ps correspond to 2.45MeV DD neutrons and 14.03MeV DT neutrons. The instrument is able to measure the fusion reaction history at yields 1.5 x 10 9 DD neutrons, about 4 x 10 8 DT neutrons are required for a similar quality signal. (authors)

  11. Recent developments in heavy-ion fusion reactions around the Coulomb barrier

    Directory of Open Access Journals (Sweden)

    Hagino K.

    2016-01-01

    Full Text Available The nuclear fusion is a reaction to form a compound nucleus. It plays an important role in several circumstances in nuclear physics as well as in nuclear astrophysics, such as synthesis of superheavy elements and nucleosynthesis in stars. Here we discuss two recent theoretical developments in heavy-ion fusion reactions at energies around the Coulomb barrier. The first topic is a generalization of the Wong formula for fusion cross sections in a single-channel problem. By introducing an energy dependence to the barrier parameters, we show that the generalized formula leads to results practically indistinguishable from a full quantal calculation, even for light symmetric systems such as 12C+12C, for which fusion cross sections show an oscillatory behavior. We then discuss a semi-microscopic modeling of heavy-ion fusion reactions, which combine the coupled-channels approach to the state-of-the-art nuclear structure calculations for low-lying collective motions. We apply this method to subbarrier fusion reactions of 58Ni+58Ni and 40Ca+58Ni systems, and discuss the role of anharmonicity of the low-lying vibrational motions.

  12. Microscopic study on dynamic barrier in fusion reactions

    International Nuclear Information System (INIS)

    Wu Xizhen; Tian Junlong; Zhao Kai; Li Zhuxia; Wang Ning

    2004-01-01

    The authors briefly review the fusion process of very heavy nuclear systems and some theoretical models. The authors propose a microscopic transport dynamic model, i.e. the Improved Quantum Molecular Dynamic model, for describing fusion reactions of heavy systems, in which the dynamical behavior of the fusion barrier in heavy fusion systems has been studied firstly. The authors find that with the incident energy decreasing the lowest dynamic barrier is obtained which approaches to the adiabatic static barrier and with increase of the incident energy the dynamic barrier goes up to the diabatic static barrier. The authors also indicate that how the dynamical fusion barrier is correlated with the development of the configuration of fusion partners along the fusion path. Associating the single-particle potentials obtained at different stages of fusion with the Two Center Shell Model, authors can study the time evolution of the single particle states of fusion system in configuration space of single particle orbits along the fusion path. (author)

  13. Detailed determination of the fusion nuclear radius in reactions involving weakly bound projectiles

    International Nuclear Information System (INIS)

    Gomez Camacho, A.; Aguilera, E. F.; Quiroz, E. M.

    2007-01-01

    A detailed determination of the fusion radius parameter is performed within the Distorted Wave Born Approximation for reactions involving weakly bound projectiles. Specifically, a simultaneous X 2- analysis of elastic and fusion cross section data is done using a Woods-Saxon potential with volume and surface parts. The volume part is assumed to be responsible for fusion reactions while the surface part for all other direct reactions. It is proved that in order to fit fusion data, particularly for energies below the Coulomb barrier where fusion is enhanced, it is necessary to have a value of around 1.4 fm for the fusion radial parameter of the fusion potential (W F ). This value is much higher than that frequently used in Barrier Penetration models (1.0 fm). The calculations are performed for reactions involving the weakly bound projectile 9 Be with several medium mass targets. (Author)

  14. Fusion of 6Li with 159Tb at near-barrier energies

    International Nuclear Information System (INIS)

    Pradhan, M. K.; Mukherjee, A.; Basu, P.; Goswami, A.; Kshetri, R.; Roy, Subinit; Chowdhury, P. Roy; Sarkar, M. Saha; Palit, R.; Parkar, V. V.; Santra, S.; Ray, M.

    2011-01-01

    Complete and incomplete fusion cross sections for 6 Li + 159 Tb have been measured at energies around the Coulomb barrier by the γ-ray method. The measurements show that the complete fusion cross sections at above-barrier energies are suppressed by ∼34% compared to coupled-channel calculations. A comparison of the complete fusion cross sections at above-barrier energies with the existing data for 11,10 B + 159 Tb and 7 Li + 159 Tb shows that the extent of suppression is correlated with the α separation energies of the projectiles. It has been argued that the Dy isotopes produced in the reaction 6 Li + 159 Tb at below-barrier energies are primarily due to the d transfer to unbound states of 159 Tb, while both transfer and incomplete fusion processes contribute at above-barrier energies.

  15. Quasi-elastic scattering an alternative tool for mapping the fusion barriers for heavy-ion induced fusion reaction

    International Nuclear Information System (INIS)

    Behera, B.R.

    2016-01-01

    Heavy element synthesis through heavy-ion induced fusion reaction is an active field in contemporary nuclear physics. Exact knowledge of fusion barrier is one of the essential parameters for planning any experiments for heavy element production. Theoretically there are many models available to predict the exact barrier. Though these models are successful for predicting the fusion of medium mass nuclei, it somehow fails for predicting the exact location of barrier for fusion of heavy nuclei. Experimental determination of barrier for such reactions is required for future experiments for the synthesis of heavy elements. Traditionally fusion barrier is determined taking a double derivative of fusion excitation function. However, such method is difficult in case of fusion of heavy nuclei due to its very low fusion/capture cross section and its experimental complications. Alternatively fusion barrier can be determined by measuring the quasi-elastic cross section at backward angles. This method can be applied for determining the fusion barrier for the fusion of heavy nuclei. Experimental determination of fusion barrier by different methods and comparison of the fusion excitation function and quasi-elastic scattering methods for the determination of fusion barrier are reviewed. At IUAC, New Delhi recently a program has been started for the measurement of fusion barrier through quasi-elastic scattering methods. The experimental facility and the first results of the experiments carried out with this facility are presented. (author)

  16. Fusion dynamics in 40Ca induced reactions

    International Nuclear Information System (INIS)

    Prasad, E.; Hinde, D.J.; Williams, E.

    2017-01-01

    Synthesis of superheavy elements (SHEs) and investigation of their properties are among the most challenging research topics in modern science. A non-compound nuclear process called quasi fission is partly responsible for the very low production cross sections of SHEs. The formation and survival probabilities of the compound nucleus (CN) strongly depend on the competition between fusion and quasi fission. A clear understanding of these processes and their dynamics is required to make reliable predictions of the best reactions to synthesise new SHEs. All elements beyond Nh are produced using hot fusion reactions and beams of 48 Ca were used in most of these experiments. In this context a series of fission measurements have been carried out at the Australian National University (ANU) using 40;48 Ca beams on various targets ranging from 142 Nd to 249 Cf. Some of the 40 Ca reactions will be discussed in this symposium

  17. Analysis of production of forward-angle fragments in the 22Ne (40 AMeV + 9Be reaction

    Directory of Open Access Journals (Sweden)

    G. Kaminski

    2008-12-01

    Full Text Available A mechanisms of production of forward-emitted fragments in the 22Ne (40 АMeV + 9Be reaction are investigated. Inclusive velocity and isotopic distributions of products with 3 ≤ Z ≤ 11 were measured on the fragment separator COMBAS. The contribution of direct processes and dissipative ones is presented. Gaussian fitting functions according to Goldhaber formalism has been used to estimate direct components of fragments velocity distributions. Experimental data have been compared to geometric incomplete fusion model predictions. Incomplete fusion model was the first time applied for light nuclei as in the studied reaction system. Overall agreement of simulations with experiment in description of velocity distributions have been achieved for fragments with atomic number close to the projectile mass and for stable isotopes. Discrepancies for other products are the result of transition from incomplete fusion to direct processes with collisions of clusters in the participant zone.

  18. Plasma fluctuations and confinement of fusion reaction products

    International Nuclear Information System (INIS)

    Coppi, B.; Pegoraro, F.

    1981-01-01

    The interaction between the fluctuations that can be excited in a magnetically confined plasma and the high-energy-particle population produced by fusion reactions is analyzed in view of its relevance to the process of thermonuclear ignition. The spectrum of the perturbations that, in the absence of fusion reaction products, would be described by the incompressible ideal magnetohydrodynamic approximation is studied considering finite value of the plasma pressure relative ot the magnetic pressure. The combined effects of the magnetic field curvature and shear are taken into account and the relevant spectrum is shown to consist of a continuous portion, that could be identified as a mixture of shear-Alfven and interchange oscillations, and a discrete unstable part corresponding to the so-called ballooning modes. The rate of diffusion of the fusion reaction products induced by oscillations in the continuous part of the spectrum, as estimated from the appropriate quasi-linear theory, is found to be significantly smaller than could be expected if normal modes (i.e., nonconvective solutions) were excited. However, a relatively wide intermediate region is identified where opalescent fluctuations, capable of achieving significant amplitudes and corresponding to a quasi-discrete spectrum, can be excited

  19. Study of incomplete fusion sensitivity to projectile structure from forward recoil range distribution measurement

    International Nuclear Information System (INIS)

    Kumar, Harish; Tali, Suhail A.; Afzal Ansari, M.

    2017-01-01

    Recently, the projectile structure is found to affect the incomplete fusion (ICF) process by using α- and non-α-cluster structured projectiles which is explored in terms of projectile α-Q-value and is still limited only for a very few systems. Keeping in view the recent aspects especially the projectile structure effect on ICF, the present work is carried out in the series of experiment by using α- and non-α-cluster structured projectiles. Presently, the FRRDs of evaporation residues (ERs) produced in 13 C + 175 Lu system have been measured at ≈ 88 MeV energy. In this work, an attempt has been made to have a better knowledge of projectile α-Q-value effect on ICF

  20. Fusion reaction around the Coulomb barrier with neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Atsushi [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1997-07-01

    Two fusion reactions with neutron-rich nuclei are reported in this work. On the first reaction: {sup 9,10,11}Be+{sup 209}Bi, the fusion cross sections around the coulomb barrier were measured by determing {alpha} disintegration from compound nucleus Fr. In the field of 10-100 mb, the same total fusion cross sections were obtained. The phenomenon {sup 11}Be(neutron halo nucleus) alone increased and decreased was not observed. The fusion cross sections of {sup 27,29,31}Al+{sup 197}Au system were determined by using 130 kcps and 30 kcps of beam strength of {sup 29,31}Al, respectively. The value of {sup 27}Al was reproduced by calculation, but that of {sup 29}Al increased around barrier which could not be explained by CCDEF calculation. (S.Y.)

  1. Many-body treatment of subbarrier fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, Akira; Kondratyev, V. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Bonasera, A.

    1998-07-01

    The subbarrier fusion of heavy-ions at energies around the Coulomb barrier is studied by using semiclassical mean-field theory. The paths connecting entrance and exit subbarrier fusion reaction channels are found by incorporating the Wick transformation into the mean-field kinetic equation. The polarization and deformation of nuclei is shown to lower the barrier height. It is demonstrated that preequilibrium nucleon exchange in classically forbidden region gives rise to the nonlocal effects lowering the effective barrier further at small relative distance. (author)

  2. Fusion barrier distributions in 28,30Si + 124Sn reactions

    International Nuclear Information System (INIS)

    Danu, L.S.; Nayak, B.K.; Biswas, D.C.; Saxena, A.; Thomas, R.G.; Mirgule, E.T.; Choudhury, R.K.

    2009-01-01

    The coupling of various degrees of freedom such as static deformation, inelastic excitation and nucleon transfer with the relative motion gives rise to a distribution of barrier in heavy ion induced fusion reactions. The barrier distribution is a fingerprint of the reaction characterizing the important channel couplings. The relative importance of various couplings in fusion reaction is of topical interest. In an earlier study with deformed projectiles 28,30 Si on 115 In target, it was observed that the barrier distributions get affected due to coulomb reorientation of the deformed projectile nuclei in the field of target nucleus thus giving rise to fusion hindrance at sub-barrier energies. In that study, we considered deformed projectile rotational and positive Q-value transfer channel couplings to relative motion in fusion for investigation of Coulomb reorientation and no inelastic coupling of the 115 In target was considered. In the present work, we have extended the measurements with 124 Sn target and inelastic coupling of target has been considered in the coupled channel calculations. The fusion barrier distributions for 28,30 Si + 124 Sn systems have been obtained by quasi-elastic scattering measurements at backward angles and the results compared with the predictions of coupled channel calculations

  3. Recent results on fusion and direct reactions with weakly bound stable nuclei

    International Nuclear Information System (INIS)

    Shrivastava, A.

    2011-01-01

    Recent measurements of fusion and direct reactions in case of weakly bound stable nuclei at extreme sub-barrier energies using a sensitive off beam technique are presented. First section deals with deep sub-barrier fusion cross-section measurement for 67 Li + 198 Pt followed by the study of fragment capture reaction of 7 Li + 198 Pt. Deviation in the slope of the fusion excitation function, as observed in case of medium heavy systems, is absent in the present asymmetric systems at these low energies. This study shows the absence of fusion hindrance, suggesting modifications in models that explain deep sub-barrier fusion data to incorporate weakly bound asymmetric systems

  4. Diagnostic technique for measuring fusion reaction rate for inertial confinement fusion experiments at Shen Guang-III prototype laser facility

    International Nuclear Information System (INIS)

    Wang Feng; Peng Xiao-Shi; Liu Shen-Ye; Xu Tao; Kang Dong-Guo

    2013-01-01

    A study is conducted using a two-dimensional simulation program (Lared-s) with the goal of developing a technique to evaluate the effect of Rayleigh-Taylor growth in a neutron fusion reaction region. Two peaks of fusion reaction rate are simulated by using a two-dimensional simulation program (Lared-s) and confirmed by the experimental results. A neutron temporal diagnostic (NTD) system is developed with a high temporal resolution of ∼ 30 ps at the Shen Guang-III (SG-III) prototype laser facility in China, to measure the fusion reaction rate history. With the shape of neutron reaction rate curve and the spherical harmonic function in this paper, the degree of Rayleigh-Taylor growth and the main source of the neutron yield in our experiment can be estimated qualitatively. This technique, including the diagnostic system and the simulation program, may provide important information for obtaining a higher neutron yield in implosion experiments of inertial confinement fusion

  5. Semi empirical model for astrophysical nuclear fusion reactions of 1≤Z≤15

    International Nuclear Information System (INIS)

    Manjunatha, H.C.; Seenappa, L.; Sridhar, K.N.

    2017-01-01

    The fusion reaction is one of the most important reactions in the stellar evolution. Due to the complicated reaction mechanism of fusion, there is great uncertainty in the reaction rate which limits our understanding of various stellar objects. Low z elements are formed through many fusion reactions such as "4He+"1"2C→"1"6O, "1"2C+"1"2C→"2"0Ne+"4He, "1"2C+"1"2C→"2"3Na, "1"2C+"1"2C→"2"3Mg, "1"6O+"1"6O→"2"8Si+"4He, "1"2C+"1H→"1"3N and "1"3C+"4He→"1"6O. A detail study is required on Coulomb and nuclear interaction in formation of low Z elements in stars through fusion reactions. For astrophysics, the important energy range extends from 1 MeV to 3 MeV in the center of mass frame, which is only partially covered by experiments. In the present work, we have studied the basic fusion parameters such as barrier heights (V_B), positions (R_B), curvature of the inverted parabola (ħω_1) for fusion barrier, cross section and compound nucleus formation probability (P_C_N) and fusion process in the low Z element (1≤Z≤15) formation process. For each isotope, we have studied all possible projectile-target combinations. We have also studied the astrophysical S(E) factor for these reactions. Based on this study, we have formulated the semi empirical relations for barrier heights (V_B), positions (R_B), curvature of the inverted parabola and hence for the fusion cross section and astrophysical S(E) factor. The values produced by the present model compared with the experiments and data available in the literature. (author)

  6. Competition between fusion and quasi-fission in heavy ion induced reactions

    International Nuclear Information System (INIS)

    Back, B.B.

    1986-09-01

    Quantitative analyses of angular distributions and angle-mass correlations have been applied to the U + Ca reaction to obtain upper limit estimates for the cross sections for complete fusion near or below the interaction barrier. Extrapolating to the systems Ca + Cm and Ca + Es using the well established scaling properties of the extra push model, an estimate of the cross sections relevant to the efforts of synthesizing super-heavy elements in the region Z = 116 and N = 184 via heavy-ion fusion reactions are obtained. A simple evaporation calculation using properties of the super heavy elements shows that the failure to observe super-heavy elements with the Ca + Cm reaction is consistent with estimates of the complete fusion process. 33 refs., 9 figs., 1 tab

  7. Cold fusion in symmetric 90Zr induced reactions

    International Nuclear Information System (INIS)

    Keller, J.G.; Schmidt, K.H.; Hessberger, F.P.; Muenzenberg, G.; Reisdorf, W.; Clerc, H.G.; Sahm, C.C.

    1985-08-01

    Excitation functions for evaporation residues were measured for the reactions 90 Zr+ 89 Y, 90 Zr, 92 Zr, 96 Zr, and 94 Mo. Deexcitation only by γ radiation was found for the compound nuclei 179 Au, 180 Hg, 182 Hg, and 184 Pb. The cross sections for this process were found to be considerably larger than predicted by a statistical-model calculation using standard parameters for the γ-strength function. Fusion probabilities as well as fusion-barrier distributions were deduced from the measured cross sections. There are strong nuclear structure effects in subbarrier fusion. For energies far below the fusion barrier the increase of the fusion probabilities with increasing energy is found to be much steeper than predicted by WKB calculations. As a by-product of this work new α-spectroscopic information could be obtained for neutron deficient isotopes between Ir and Pb. (orig.)

  8. Fusion reactions initiated by laser-accelerated particle beams in a laser-produced plasma

    International Nuclear Information System (INIS)

    Labaune, C.; Baccou, C.; Loisel, G.; Yahia, V.; Depierreux, S.; Goyon, C.; Rafelski, J.

    2013-01-01

    The advent of high-intensity-pulsed laser technology enables the generation of extreme states of matter under conditions that are far from thermal equilibrium. This in turn could enable different approaches to generating energy from nuclear fusion. Relaxing the equilibrium requirement could widen the range of isotopes used in fusion fuels permitting cleaner and less hazardous reactions that do not produce high-energy neutrons. Here we propose and implement a means to drive fusion reactions between protons and boron-11 nuclei by colliding a laser-accelerated proton beam with a laser-generated boron plasma. We report proton-boron reaction rates that are orders of magnitude higher than those reported previously. Beyond fusion, our approach demonstrates a new means for exploring low-energy nuclear reactions such as those that occur in astrophysical plasmas and related environments. (authors)

  9. Classical simulations of heavy-ion fusion reactions and weakly ...

    Indian Academy of Sciences (India)

    82, No. 5. — journal of. May 2014 physics pp. 879–891. Classical simulations of heavy-ion fusion reactions and weakly-bound projectile breakup reactions ... on the collision energy and the moment of inertia of the deformed nucleus. ... where each individual nucleus consists of a number of protons and neutrons, in some.

  10. Involvement of Receptor Activator of Nuclear Factor-κB Ligand (RANKL)-induced Incomplete Cytokinesis in the Polyploidization of Osteoclasts*

    Science.gov (United States)

    Takegahara, Noriko; Kim, Hyunsoo; Mizuno, Hiroki; Sakaue-Sawano, Asako; Miyawaki, Atsushi; Tomura, Michio; Kanagawa, Osami; Ishii, Masaru; Choi, Yongwon

    2016-01-01

    Osteoclasts are specialized polyploid cells that resorb bone. Upon stimulation with receptor activator of nuclear factor-κB ligand (RANKL), myeloid precursors commit to becoming polyploid, largely via cell fusion. Polyploidization of osteoclasts is necessary for their bone-resorbing activity, but the mechanisms by which polyploidization is controlled remain to be determined. Here, we demonstrated that in addition to cell fusion, incomplete cytokinesis also plays a role in osteoclast polyploidization. In in vitro cultured osteoclasts derived from mice expressing the fluorescent ubiquitin-based cell cycle indicator (Fucci), RANKL induced polyploidy by incomplete cytokinesis as well as cell fusion. Polyploid cells generated by incomplete cytokinesis had the potential to subsequently undergo cell fusion. Nuclear polyploidy was also observed in osteoclasts in vivo, suggesting the involvement of incomplete cytokinesis in physiological polyploidization. Furthermore, RANKL-induced incomplete cytokinesis was reduced by inhibition of Akt, resulting in impaired multinucleated osteoclast formation. Taken together, these results reveal that RANKL-induced incomplete cytokinesis contributes to polyploidization of osteoclasts via Akt activation. PMID:26670608

  11. Process and device for energy production from thermonuclear fusion reactions

    International Nuclear Information System (INIS)

    Bussard, R.W.; Coppi, Bruno.

    1977-01-01

    An energy generating system is described using a fusion reaction. It includes several contrivances for confining a plasma in an area, a protective device around a significant part of each of these confinement contrivances, an appliance for introducing a fusion reaction fuel in each of the confinements so that the plasma may be formed. Each confinement can be separated from the protective device so that it may be replaced by another. The system is connected to the confinements, to the protective devices or to both. It enables the thermal energy to be extracted and transformed into another form, electric, mechanical or both [fr

  12. Stochastic semi-classical description of sub-barrier fusion reactions

    Directory of Open Access Journals (Sweden)

    Ayik Sakir

    2011-10-01

    Full Text Available A semi-classical method that incorporates the quantum effects of the low-lying vibrational modes is applied to fusion reactions. The quantum effect is simulated by stochastic sampling of initial zero-point fluctuations of the surface modes. In this model, dissipation of the relative energy into non-collective excitations of nuclei can be included straightforwardly. The inclusion of dissipation is shown to increase the agreement with the fusion cross section data of Ni isotopes.

  13. Involvement of Receptor Activator of Nuclear Factor-κB Ligand (RANKL)-induced Incomplete Cytokinesis in the Polyploidization of Osteoclasts.

    Science.gov (United States)

    Takegahara, Noriko; Kim, Hyunsoo; Mizuno, Hiroki; Sakaue-Sawano, Asako; Miyawaki, Atsushi; Tomura, Michio; Kanagawa, Osami; Ishii, Masaru; Choi, Yongwon

    2016-02-12

    Osteoclasts are specialized polyploid cells that resorb bone. Upon stimulation with receptor activator of nuclear factor-κB ligand (RANKL), myeloid precursors commit to becoming polyploid, largely via cell fusion. Polyploidization of osteoclasts is necessary for their bone-resorbing activity, but the mechanisms by which polyploidization is controlled remain to be determined. Here, we demonstrated that in addition to cell fusion, incomplete cytokinesis also plays a role in osteoclast polyploidization. In in vitro cultured osteoclasts derived from mice expressing the fluorescent ubiquitin-based cell cycle indicator (Fucci), RANKL induced polyploidy by incomplete cytokinesis as well as cell fusion. Polyploid cells generated by incomplete cytokinesis had the potential to subsequently undergo cell fusion. Nuclear polyploidy was also observed in osteoclasts in vivo, suggesting the involvement of incomplete cytokinesis in physiological polyploidization. Furthermore, RANKL-induced incomplete cytokinesis was reduced by inhibition of Akt, resulting in impaired multinucleated osteoclast formation. Taken together, these results reveal that RANKL-induced incomplete cytokinesis contributes to polyploidization of osteoclasts via Akt activation. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. Potential design modifications for the High Yield Lithium Injection Fusion Energy (HYLIFE) reaction chamber

    International Nuclear Information System (INIS)

    Pitts, J.H.; Hovingh, J.; Meier, W.R.; Monsler, M.J.; Powell, E.G.; Walker, P.E.

    1979-01-01

    Generation of electric power from inertial confinement fusion requires a reaction chamber. One promising type, the High Yield Lithium Injection Fusion Energy (HYLIFE) chamber, includes a falling array of liquid lithium jets. These jets act as: (1) a renewable first wall and blanket to shield metal components from x-ray and neutron exposure, (2) a tritium breeder to replace tritium burned during the fusion process, and (3) an absorber and transfer medium for fusion energy. Over 90% of the energy produced in the reaction chamber is absorbed in the lithium jet fall. Design aspects are included

  15. Fusion evaporation-residue cross sections for 28Si+40Ca at E(28Si)=309, 397, and 452 MeV

    International Nuclear Information System (INIS)

    Vineyard, M.F.; Bauer, J.S.; Crum, J.F.; Gosdin, C.H.; Trotter, R.S.; Kovar, D.G.; Beck, C.; Henderson, D.J.; Janssens, R.V.F.; Wilkins, B.D.; Maguire, C.F.; Mateja, J.F.; Prosser, F.W.; Stephans, G.S.F.

    1992-01-01

    Velocity distributions of mass-identified evaporation residues produced in the 28 Si+ 40 Ca reaction have been measured at bombarding energies of 309, 397, and 452 MeV using time-of-flight techniques. These distributions were used to identify evaporation residues and to separate the complete-fusion and incomplete-fusion components. Angular distributions and upper limits for the total evaporation-residue and complete-fusion evaporation-residue cross sections were extracted at all three bombarding energies. The complete-fusion evaporation-residue cross sections and the deduced critical angular momenta are compared with earlier measurements and the predictions of existing models. The ratios of the complete-fusion evaporation-residue cross section to the total evaporation-residue cross section, along with those measured for the 28 Si+ 12 C and 28 Si+ 28 Si systems at the same energies, support the entrance-channel mass-asymmetry dependence of the incomplete-fusion evaporation-residue process reported earlier

  16. Investigations of nuclear structure and nuclear reactions induced by complex projectiles

    International Nuclear Information System (INIS)

    Sarantites, D.G.

    1991-01-01

    The research program of our group touches five areas of nuclear physics: (1) Nuclear structure studies at high spin; (2) Studies at the interface between structure and reactions; (3) Production and study of hot nuclei; (4) Incomplete fusion and fragmentation reactions; and (5) Development and use of novel techniques and instrumentation in the above areas of research. The papers from these areas are discussed in this report

  17. Study of Cold Fusion Reactions Using Collective Clusterization Approach

    Science.gov (United States)

    Kaur, Gurjit; Sandhu, Kirandeep; Sharma, Manoj K.

    2017-10-01

    Within the framework of the dynamical cluster decay model (DCM), the 1n evaporation cross-sections ({σ }1n) of cold fusion reactions (Pb and Bi targets) are calculated for {Z}{CN}=104-113 superheavy nuclei. The calculations are carried out in the fixed range of excitation energy {E}{CN}* =15+/- 1 {MeV}, so that the comparative analysis of reaction dynamics can be worked out. First of all, the fission barriers (B f ) and neutron separation energies ({S}1n) are estimated to account the decreasing cross-sections of cold fusion reactions. In addition to this, the importance of hot optimum orientations of β 2i-deformed nuclei over cold one is explored at fixed angular momentum and neck-length parameters. The hot optimum orientations support all the target-projectile (t,p) combinations, which are explored experimentally in the cold fusion reactions. Some new target-projectile combinations are also predicted for future exploration. Further, the 1n cross-sections are addressed for {Z}{CN}=104-113 superheavy nuclei at comparable excitation energies which show the decent agrement with experimental data upto {Z}{CN}=109 nuclei. Finally, to understand the dynamics of higher-Z superheavy nuclei, the cross-sections are also calculated at maximum available energies around the Coulomb barrier and the effect of non-sticking moment of inertia ({I}{NS}) is also investigated at these energies. Supported by the Council of Scientific and Industrial Research (CSIR), in the Form of Research Project Grant No. 03(1341)/15/EMR-II, and to DST, New Delhi, for INSPIRE-Fellowship Grant No. DST/INSPIRE/03/2015/000199

  18. Constraining statistical-model parameters using fusion and spallation reactions

    Directory of Open Access Journals (Sweden)

    Charity Robert J.

    2011-10-01

    Full Text Available The de-excitation of compound nuclei has been successfully described for several decades by means of statistical models. However, such models involve a large number of free parameters and ingredients that are often underconstrained by experimental data. We show how the degeneracy of the model ingredients can be partially lifted by studying different entrance channels for de-excitation, which populate different regions of the parameter space of the compound nucleus. Fusion reactions, in particular, play an important role in this strategy because they fix three out of four of the compound-nucleus parameters (mass, charge and total excitation energy. The present work focuses on fission and intermediate-mass-fragment emission cross sections. We prove how equivalent parameter sets for fusion-fission reactions can be resolved using another entrance channel, namely spallation reactions. Intermediate-mass-fragment emission can be constrained in a similar way. An interpretation of the best-fit IMF barriers in terms of the Wigner energies of the nascent fragments is discussed.

  19. Multivariate curve resolution of incomplete fused multiset data from chromatographic and spectrophotometric analyses for drug photostability studies

    International Nuclear Information System (INIS)

    Luca, Michele De; Ragno, Gaetano; Ioele, Giuseppina; Tauler, Romà

    2014-01-01

    Highlights: • A new MCR-ALS algorithm is proposed for the analysis of incomplete fused multiset. • Resolution of the data allowed the description of amiloride kinetic photodegradation. • The new MCR-ALS algorithm can be easily applied to other drugs and chemicals. - Abstract: An advanced and powerful chemometric approach is proposed for the analysis of incomplete multiset data obtained by fusion of hyphenated liquid chromatographic DAD/MS data with UV spectrophotometric data from acid–base titration and kinetic degradation experiments. Column- and row-wise augmented data blocks were combined and simultaneously processed by means of a new version of the multivariate curve resolution-alternating least squares (MCR-ALS) technique, including the simultaneous analysis of incomplete multiset data from different instrumental techniques. The proposed procedure was applied to the detailed study of the kinetic photodegradation process of the amiloride (AML) drug. All chemical species involved in the degradation and equilibrium reactions were resolved and the pH dependent kinetic pathway described

  20. Multivariate curve resolution of incomplete fused multiset data from chromatographic and spectrophotometric analyses for drug photostability studies

    Energy Technology Data Exchange (ETDEWEB)

    Luca, Michele De, E-mail: michele.deluca@unical.it [Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Via P. Bucci, Rende, CS 87036 (Italy); Ragno, Gaetano; Ioele, Giuseppina [Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Via P. Bucci, Rende, CS 87036 (Italy); Tauler, Romà [Department of Environmental Chemistry, IDAEA-CSIC, C/Jordi Girona, 18-26, Barcelona 08034 (Spain)

    2014-07-21

    Highlights: • A new MCR-ALS algorithm is proposed for the analysis of incomplete fused multiset. • Resolution of the data allowed the description of amiloride kinetic photodegradation. • The new MCR-ALS algorithm can be easily applied to other drugs and chemicals. - Abstract: An advanced and powerful chemometric approach is proposed for the analysis of incomplete multiset data obtained by fusion of hyphenated liquid chromatographic DAD/MS data with UV spectrophotometric data from acid–base titration and kinetic degradation experiments. Column- and row-wise augmented data blocks were combined and simultaneously processed by means of a new version of the multivariate curve resolution-alternating least squares (MCR-ALS) technique, including the simultaneous analysis of incomplete multiset data from different instrumental techniques. The proposed procedure was applied to the detailed study of the kinetic photodegradation process of the amiloride (AML) drug. All chemical species involved in the degradation and equilibrium reactions were resolved and the pH dependent kinetic pathway described.

  1. Reaching to a featured formula to deduce the energy of the heaviest particles producing from the controlled thermonuclear fusion reactions

    Science.gov (United States)

    Majeed, Raad H.; Oudah, Osamah N.

    2018-05-01

    Thermonuclear fusion reaction plays an important role in developing and construction any power plant system. Studying the physical behavior for the possible mechanism governed energies released by the fusion products to precise understanding the related kinematics. In this work a theoretical formula controlled the general applied thermonuclear fusion reactions is achieved to calculating the fusion products energy depending upon the reactants physical properties and therefore, one can calculate other parameters governed a given reaction. By using this formula, the energy spectrum of 4He produced from T-3He fusion reaction has been sketched with respect to reaction angle and incident energy ranged from (0.08-0.6) MeV.

  2. Breakup-fusion analyses of light ion induced stripping reactions to both bound and unbound regions

    International Nuclear Information System (INIS)

    Lee, Y.J.

    1987-01-01

    The breakup-fusion theory developed recently by our group at the University of Texas has been very successful in explaining observed continuum spectra of particles emitted from breakup type reactions, such as (d,p), (h,p), (h,d), (α,p), and (α,t) reactions. The aim of the present work is to extend the breakup-fusion formalism to calculate the usual stripping reaction, in which a nucleon or a nucleon-cluster is transferred into abound orbit in the target nucleus. With this extension, it is now possible to calculate the spectra of particles emitted from stripping type reactions. We particularly explore the possibility of using the breakup-fusion theory as a spectroscopic tool to obtain information about single particle states in both bound and unbound regions. For this purpose, we extend the theory so as to include the spin-orbit interaction between the transferred particle and the target which has been neglected in all the breakup-fusion studies made in the past. We then apply the thus extended breakup-fusion theory to analyze data of (d,p) and (α,t) reactions. The results of the calculations fit the observed spectra very well and the BF method is shown indeed to be useful for extracting information about the single particle states observed as bumps in both the continuum and discrete regions

  3. Charge-exchange and fusion reaction measurements during compression experiments with neutral beam heating in the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Kaita, R.; Heidbrink, W.W.; Hammett, G.W.

    1986-04-01

    Adiabatic toroidal compression experiments were performed in conjunction with high power neutral beam injection in the Tokamak Fusion Test Reactor (TFTR). Acceleration of beam ions to energies nearly twice the injection energy was measured with a charge-exchange neutral particle analyzer. Measurements were also made of 2.5 MeV neutrons and 15 MeV protons produced in fusion reactions between the deuterium beam ions and the thermal deuterium and 3 He ions, respectively. When the plasma was compressed, the d(d,n) 3 He fusion reaction rate increased a factor of five, and the 3 He(d,p) 4 He rate by a factor of twenty. These data were simulated with a bounce-averaged Fokker-Planck program, which assumed conservation of angular momentum and magnetic moment during compression. The results indicate that the beam ion acceleration was consistent with adiabatic scaling

  4. Direct inner shell ionization accompanying heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Sujkowski, Z.

    1987-07-01

    51 V+ 40 Ar (180 MeV) fusion reaction is studied by means of K X-ray-particle-γ-ray coincidences. K X-ray yields associated with various evaporation residues are determined separately for two ionization processes: the direct ionization by the projectile prior to the nuclear interaction and the postcollisional ionization due to the internal conversion of γ-rays. Implications for possible measurements of nuclear reaction times are discussed. 24 refs., 9 figs., 2 tabs. (author)

  5. Cold fusion reactions with 48Ca

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.; Jost, D.T.; Tuerler, A.

    1989-04-01

    Cold fusion reactions with 48 Ca on the targets 208 Pb, 209 Bi, 197 Au, 184 W, 180 Hf are reported. The experiments were performed at the velocity filter SHIP of GSI. The maximum cross sections show a steep descent by about four orders of magnitude when going from 224 Th to 228 U as compound nuclei. Between uranium and einsteinium the cross sections stay rather low and increase by about two orders of magnitude for nobelium. For lawrencium the cross section decrease again. 7 figs., 1 tab., 38 refs

  6. Investigation of incomplete linear momentum transfer in heavy ion reactions at intermediate energies

    International Nuclear Information System (INIS)

    Leray, S.

    1986-07-01

    At intermediate energies, heavy ion central collisions lead to the incomplete fusion of the incident nuclei while part of the initial linear momentum is carried away by fast light particles. Experiments were performed with 30 MeV per nucleon neon and 20, 35 and 44 MeV per nucleon argon projectiles bombarding heavy targets. Results obtained with 30 MeV per nucleon neon and 20 MeV per nucleon argon beams are in good agreement with an empirical law established with lighter projectiles. On the contrary, 35 and 44 MeV per nucleon argon projectiles do not follow the same law and fission fragments progressively disappear. A simple model explains the evolution of the amount of transferred linear momentum versus incident energy. The disappearance of the fusion products of the composite system observed with argon projectiles beyond 35 MeV per nucleon is explained by a limitation of the excitation energy per nucleon which can be deposited in a nucleus. The limit is evaluated from nucleon binding energy in nuclei and probability to emit clusters and is in good agreement with experimental data. Because of the coupling between intrinsic motion of nucleons and relative motion of nuclei, some nucleons have a kinetic energy high enough to be emitted: a theoretical model is proposed which rather well fits the data concerning fast nucleons but cannot explain the measured amounts of transferred linear momentum. This is attributed to the existence of other mechanisms [fr

  7. Evaluation of charged-particle reactions for fusion applications

    International Nuclear Information System (INIS)

    White, R.M.; Resler, D.A.; Warshaw, S.I.

    1991-01-01

    New evaluations of the total reaction cross sections for 2 H(d,n) 3 He, 2 H(d,p) 3 H, 3 H(t,2n) 4 He, 3 H(d,n) 4 He, and 3 He(d,p) 4 He have been completed. These evaluations are based on all known published data from 1946 to 1990 and include over 1150 measured data points from 67 references. The purpose of this work is to provide a consistent and well-documented set of cross sections for use in calculations relating to fusion energy research. A new thermonuclear data file, TDF, and a library of FORTRAN subprograms to read the file have been developed. Calculated from the new evaluations, the TDF file contains information on the Maxwellian-averaged reaction rates as a function of reaction and plasma temperature and the Maxwellian-averaged average energy of the interacting particles and reaction products. Routines are included that provide thermally-broadened spectral information for the secondary reaction products. 67 refs., 18 figs

  8. Fusion and nonfusion phenomena in the 6Li+40Ca reaction at 156 MeV

    International Nuclear Information System (INIS)

    Brzychczyk, J.; Freindl, L.; Grotowski, K.

    1982-01-01

    Reaction products from 6 Li-induced reactions on 40 Ca at 156 MeV have been studied using the dE x E identification as well as the inclusive γ-ray method. The complete fusion cross-section has been found to be σsub(f)=(77 +- 11)mb. The Z distribution of fusion evaporation residues is compared with statistical model predictions. The Z spectrum of reaction products shows a maximum at 15 6 Li break-up. (author)

  9. Fusion and nonfusion phenomena in the 6Li+40Ca reaction at 156 MeV

    International Nuclear Information System (INIS)

    Brzychczyk, J.; Freindl, L.; Grotowski, K.; Majka, Z.; Micek, S.; Planeta, R.; Uniwersytet Jagiellonski, Krakow; Albinska, M.; Buschmann, J.; Klewe-Nebenius, H.; Gils, H.J.; Rebel, H.; Zagromski, S.

    1984-01-01

    Reaction products from 6 Li-induced reactions on 40 Ca at 156 MeV have been studied using the dExE idenitification as well as the inclusive γ-ray method. The complete fusion cross section has been found to be sigmasub(F)=67 +- 20 mb. The Z-distribution of fusion evaporation residues is compared with statistical model predictions. The Z-spectrum of reaction products shows a maximum at 15 6 Li-break-up processes. (orig.)

  10. Systematic analysis of above-barrier fusion of 9,10,11Be+209Bi

    International Nuclear Information System (INIS)

    Hinde, D. J.; Dasgupta, M.

    2010-01-01

    Measurements of fusion for 9,10,11 Be allow testing of the relative importance to fusion and breakup of the α-cluster structure found in all these Be isotopes, compared with the neutron-halo structure only present for 11 Be. However, disagreements exist among different published experimental data sets for the reactions of 9,10,11 Be with 209 Bi. Accurate measurements of above-barrier cross sections for the products of complete fusion (fission and evaporation residues) in the reaction of 9 Be with 209 Bi and 208 Pb provide the basis for a reanalysis of above-barrier fusion for 10,11 Be+ 209 Bi. This includes procedures making full use of the higher precision stable beam data and resolves many of the disagreements. The improved self-consistency of the analysis allows investigation of the experimental average fusion barriers. Although showing some scatter, these suggest a higher barrier for the neutron halo nucleus 11 Be. Comparison of published cross sections for fusion associated with capture of all the charge of the projectile suggest that all these Be isotopes show significant suppression of complete fusion, a surprising result given that the α-breakup threshold energies are 1.57 MeV for 9 Be but over 7 MeV for 10,11 Be. Further experimental studies to investigate in more detail the division between complete and incomplete fusion for reactions of 10,11 Be are needed.

  11. Influence of collective nonideal shielding on fusion reaction in partially ionized classical nonideal plasmas

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2017-04-01

    The collective nonideal effects on the nuclear fusion reaction process are investigated in partially ionized classical nonideal hydrogen plasmas. The effective pseudopotential model taking into account the collective and plasma shielding effects is applied to describe the interaction potential in nonideal plasmas. The analytic expressions of the Sommerfeld parameter, the fusion penetration factor, and the cross section for the nuclear fusion reaction in nonideal plasmas are obtained as functions of the nonideality parameter, Debye length, and relative kinetic energy. It is found that the Sommerfeld parameter is suppressed due to the influence of collective nonideal shielding. However, the collective nonideal shielding is found to enhance the fusion penetration factor in partially ionized classical nonideal plasmas. It is also found that the fusion penetration factors in nonideal plasmas represented by the pseudopotential model are always greater than those in ideal plasmas represented by the Debye-Hückel model. In addition, it is shown that the collective nonideal shielding effect on the fusion penetration factor decreases with an increase of the kinetic energy.

  12. Fusion energy

    International Nuclear Information System (INIS)

    Gross, R.A.

    1984-01-01

    This textbook covers the physics and technology upon which future fusion power reactors will be based. It reviews the history of fusion, reaction physics, plasma physics, heating, and confinement. Descriptions of commercial plants and design concepts are included. Topics covered include: fusion reactions and fuel resources; reaction rates; ignition, and confinement; basic plasma directory; Tokamak confinement physics; fusion technology; STARFIRE: A commercial Tokamak fusion power plant. MARS: A tandem-mirror fusion power plant; and other fusion reactor concepts

  13. Fusion cross sections for 6,7Li + 24Mg reactions at energies below and above the barrier

    International Nuclear Information System (INIS)

    Ray, M.; Mukherjee, A.; Pradhan, M. K.; Kshetri, Ritesh; Sarkar, M. Saha; Dasmahapatra, B.; Palit, R.; Majumdar, I.; Joshi, P. K.; Jain, H. C.

    2008-01-01

    Measurement of fusion cross sections for the 6,7 Li + 24 Mg reactions by the characteristic γ-ray method has been done at energies from below to well above the respective Coulomb barriers. The fusion cross sections obtained from these γ-ray cross sections for the two systems are found to agree well with the total reaction cross sections at low energies. The relatively large difference between total cross sections and measured fusion cross sections at higher energies is consistent with the fact that other channels, in particular breakup, open up with an increase of bombarding energy. The breakup channel, however, appears not to have any influence on fusion cross sections. The critical angular momenta (l cr ) deduced from the fusion cross sections are found to have an energy dependence similar to other Li-induced reactions

  14. Study of α-particle multiplicity in 16O+196Pt fusion-fission reaction

    International Nuclear Information System (INIS)

    Kapoor, K.; Kumar, A.; Bansal, N.

    2016-01-01

    Study of dynamics of fusion-fission reaction is one of the interesting parts of heavy-ion-induced nuclear reaction. Extraction of fission time scales using different probes is of central importance for understanding the dynamics of fusion-fission process. In the past, extensive theoretical and experimental efforts have been made to understand the various aspects of the heavy ion induced fusion-fission reactions. Compelling evidences have been obtained from the earlier studies that the fission decay of hot nuclei is protracted process i.e. slowed down relative to the expectations of the standard statistical model, and large dynamical delays are required due to this hindrance. Nuclear dissipation is assumed to be responsible for this delay and more light particles are expected to be emitted during the fission process. One of neutron multiplicity measurements have been performed for the 16,18 O+ 194,198 Pt populating the CN 210,212,214,216 Rn and observed fission delay due to nuclear viscosity. In order to have complete understanding for the dynamics of 212 Rn nucleus, we measured the charged particle multiplicity for 16 O+ 196 Pt system. Study of charged particles will give us more information about the emitter in comparison to neutrons as charged particles faces Coulomb barrier and are more sensitive probe for understanding the dynamics of fusion-fission reactions. In the present work, we are reporting some of the preliminary results of charged particle multiplicity

  15. Understanding fuel magnetization and mix using secondary nuclear reactions in magneto-inertial fusion.

    Science.gov (United States)

    Schmit, P F; Knapp, P F; Hansen, S B; Gomez, M R; Hahn, K D; Sinars, D B; Peterson, K J; Slutz, S A; Sefkow, A B; Awe, T J; Harding, E; Jennings, C A; Chandler, G A; Cooper, G W; Cuneo, M E; Geissel, M; Harvey-Thompson, A J; Herrmann, M C; Hess, M H; Johns, O; Lamppa, D C; Martin, M R; McBride, R D; Porter, J L; Robertson, G K; Rochau, G A; Rovang, D C; Ruiz, C L; Savage, M E; Smith, I C; Stygar, W A; Vesey, R A

    2014-10-10

    Magnetizing the fuel in inertial confinement fusion relaxes ignition requirements by reducing thermal conductivity and changing the physics of burn product confinement. Diagnosing the level of fuel magnetization during burn is critical to understanding target performance in magneto-inertial fusion (MIF) implosions. In pure deuterium fusion plasma, 1.01 MeV tritons are emitted during deuterium-deuterium fusion and can undergo secondary deuterium-tritium reactions before exiting the fuel. Increasing the fuel magnetization elongates the path lengths through the fuel of some of the tritons, enhancing their probability of reaction. Based on this feature, a method to diagnose fuel magnetization using the ratio of overall deuterium-tritium to deuterium-deuterium neutron yields is developed. Analysis of anisotropies in the secondary neutron energy spectra further constrain the measurement. Secondary reactions also are shown to provide an upper bound for the volumetric fuel-pusher mix in MIF. The analysis is applied to recent MIF experiments [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] on the Z Pulsed Power Facility, indicating that significant magnetic confinement of charged burn products was achieved and suggesting a relatively low-mix environment. Both of these are essential features of future ignition-scale MIF designs.

  16. Synthesis and decay process of superheavy nuclei with Z=119-122 via hot-fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Ghahramany, N.; Ansari, A. [Shiraz University, Department of Physics and Biruni Observatory, College of Science, Shiraz (Iran, Islamic Republic of)

    2016-09-15

    In this research article attempts have been made to calculate the superheavy-nuclei synthesis characteristics including, the potential energy parameters, fusion probability, fusion and evaporation residue (ER) cross sections as well as, decay properties of compound nucleus and the residue nuclei formation probability for elements with Z=119-122 by using the hot-fusion reactions. It is concluded that, although a selection of double magic projectiles such as {sup 48}Ca with high binding energy, simplifies the calculations significantly due to spherical symmetric shape of the projectile, resulting in high evaporation residue cross section, unfortunately, nuclei with Z > 98 do not exist in quantities sufficient for constructing targets for the hot-fusion reactions. Therefore, practically our selection is fusion reactions with titanium projectile because the mass production of target nuclei for experimental purposes is more feasible. Based upon our findings, it is necessary, for new superheavy-nuclei production with Z > 119, to use neutron-rich projectiles and target nuclei. Finally, the maximal evaporation residue cross sections for the synthesis of superheavy elements with Z=119-122 have been calculated and compared with the previously founded ones in the literature. (orig.)

  17. INCLUSIVE SYSTEMATICS FOR SI-28+SI-28 REACTIONS BETWEEN 20 AND 35 MEV PER NUCLEON

    NARCIS (Netherlands)

    BOX, PF; GRIFFIOEN, KA; DECOWSKI, P; BOOTSMA, T; GIERLIK, E; VANNIEUWENHUIZEN, GJ; TWENHOFEL, C; KAMERMANS, R; WILSCHUT, HW; GIORNI, A; MORAND, C; DEMEYER, A; GUINET, D

    Inclusive velocity spectra of heavy ions produced in the Si-28 + Si-28 reaction at 22, 26, 30, and 35 MeV per nucleon were measured and decomposed into peripheral and central components using an analytical moving-source parametrization. The persistence of incomplete fusion followed by evaporation

  18. Description of heavy-ion fusion in terms of direct reaction theory

    International Nuclear Information System (INIS)

    Hong, S.W.

    1987-01-01

    A direct reaction description of the heavy-ion fusion, proposed by Udagawa, Kim and Tamura, has been successfully used in calculating the fusion cross sections and the spin distributions for a number of systems in the energy regions from the sub-barrier to the above-barrier region. A fusion potential is introduced in this theory and the radius of the fusion potential is treated as an adjustable parameter. The theory is thus a one-parameter theory. The results obtained by Udagawa, Kim and Tamura showed that the radius parameter ranges from 1.4 to 1.5 fm, which is much larger than the radius (1.0 fm) used in other models. A hard evidence is shown to demonstrate the necessity of the long-ranged fusion potential radius in the near-barrier region. In the above-barrier region, the use of the energy-dependent optical potential and the energy-dependent fusion potential radius is proved to be essential in reproducing the measured fusion cross sections. As a further application of the theory, the double folded potential model is utilized to provide the real part of the optical potential. The imaginary part of the optical potential is determined so that not only the elastic scattering but also the fusion cross sections can be reproduced

  19. Comparison of cross sections for C+O reactions in the second regime of complete fusion

    International Nuclear Information System (INIS)

    Beck, C.; Haas, F.; Freeman, R.M.; Heusch, B.; Coffin, J.P.; Guillaume, G.; Rami, F.; Wagner, P.

    1985-01-01

    Kinetic energy spectra, angular distributions, and elemental yield distributions have been measured for the 12 C + 16 O, 12 C + 18 O and 13 C + 17 O reaction products over an energy range from 2 to 7 times the Coulomb barrier energy. A careful kinematic analysis of the evaporation residues and comparisons with statistical model calculations show that fusion proceeds with full momentum transfer followed by a statistical decay of the compound nucleus. The competition between complete fusion process and peripheral reactions in the 12 C + 16 O system is less important than for the 12 C + 18 O and 13 C + 17 O reactions. The unexpectedly high 12 C + 16 O complete fusion cross sections are related to the possible occurence of a superdeformation of the 28 Si compound nucleus

  20. Recent experimental results in sub- and near-barrier heavy-ion fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Montagnoli, Giovanna [Dipartimento di Fisica e Astronomia, Universita di Padova (Italy); INFN Sezione di Padova (Italy); Stefanini, Alberto M. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova) (Italy)

    2017-08-15

    Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reviewed. Emphasis is given to the results obtained in the last decade, and focus is mainly on the experimental work performed concerning the influence of transfer channels on fusion cross sections and the hindrance phenomenon far below the barrier. Indeed, early data of sub-barrier fusion taught us that cross sections may strongly depend on the low-energy collective modes of the colliding nuclei, and, possibly, on couplings to transfer channels. The coupled-channels (CC) model has been quite successful in the interpretation of the experimental evidences. Fusion barrier distributions often yield the fingerprint of the relevant coupled channels. Recent results obtained by using radioactive beams are reported. At deep sub-barrier energies, the slope of the excitation function in a semi-logarithmic plot keeps increasing in many cases and standard CC calculations overpredict the cross sections. This was named a hindrance phenomenon, and its physical origin is still a matter of debate. Recent theoretical developments suggest that this effect, at least partially, may be a consequence of the Pauli exclusion principle. The hindrance may have far-reaching consequences in astrophysics where fusion of light systems determines stellar evolution during the carbon and oxygen burning stages, and yields important information for exotic reactions that take place in the inner crust of accreting neutron stars. (orig.)

  1. Isospin dependence of physical observables in Incomplete Fusion reactions at 25 MeV/nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, I., E-mail: ilombardo@lns.infn.i [Dipartimento di Fisica, Universita di Catania, Catania (Italy); INFN Laboratori Nazionali del Sud, Catania (Italy); Agodi, C.; Alba, R. [INFN Laboratori Nazionali del Sud, Catania (Italy); Amorini, F. [INFN, Sezione di Catania, Catania (Italy); Dipartimento di Fisica, Universita di Catania, Catania (Italy); Anzalone, A. [INFN Laboratori Nazionali del Sud, Catania (Italy); Berceanu, I. [Institute for Physics and Nuclear Engineering, Bucharest (Romania); Cardella, G. [INFN, Sezione di Catania, Catania (Italy); Cavallaro, S. [Dipartimento di Fisica, Universita di Catania, Catania (Italy); INFN Laboratori Nazionali del Sud, Catania (Italy); Chatterjee, M.B. [Saha Institute of Nuclear Physics, Kolkata (India); Coniglione, R. [INFN Laboratori Nazionali del Sud, Catania (Italy); DeFilippo, E. [INFN, Sezione di Catania, Catania (Italy); DiPietro, A.; Figuera, P. [INFN Laboratori Nazionali del Sud, Catania (Italy); Geraci, E.; Giuliani, G.; Grassi, L. [Dipartimento di Fisica, Universita di Catania, Catania (Italy); INFN, Sezione di Catania, Catania (Italy); Grzeszczuk, A. [Institute of Physics, University of Silesia, Katowice (Poland); LaGuidara, E. [INFN, Sezione di Catania, Catania (Italy); Centro Siciliano di Fisica Nucleare e Struttura della Materia, Catania (Italy); Lanzalone, G. [INFN Laboratori Nazionali del Sud, Catania (Italy); Libera Universita Kore, Enna (Italy); LeNeindre, N. [LPC Caen, CNRS-IN2P3, ENSICAEN, Universite de Caen, Caen (France)

    2010-03-01

    Isospin dependence of dynamical and thermodynamical physical quantities observed in the reactions {sup 40}Ca + {sup 40,48}Ca and {sup 40}Ca + {sup 46}Ti at 25 MeV/nucleon has been analyzed by means of the CHIMERA multi-detector.

  2. Search for entrance channel effects in fusion reactions via neutron evaporation

    International Nuclear Information System (INIS)

    Ajay Kumar; Kaur, J.; Kumar, A.; Singh, G.; Govil, I.M.; Rakesh Kumar; Datta, S.K.; Chatterjee, M.B.; Yogi, B.K.

    2001-01-01

    It is generally expected that the compound nuclei formed at the given excitation energies and the angular momenta follow a statistical decay pattern independent of a particular reaction that led to fusion. In order to search the entrance channel effects in the decay of compound nucleus, the reaction 16 O + 64 Zn at oxygen beam energy of 91 MeV and 95 MeV are investigated

  3. SU-F-T-140: Assessment of the Proton Boron Fusion Reaction for Practical Radiation Therapy Applications Using MCNP6

    Energy Technology Data Exchange (ETDEWEB)

    Adam, D; Bednarz, B [University of Wisconsin, Madison, WI (United States)

    2016-06-15

    Purpose: The proton boron fusion reaction is a reaction that describes the creation of three alpha particles as the result of the interaction of a proton incident upon a 11B target. Theoretically, the proton boron fusion reaction is a desirable reaction for radiation therapy applications in that, with the appropriate boron delivery agent, it could potentially combine the localized dose delivery protons exhibit (Bragg peak) and the local deposition of high LET alpha particles in cancerous sites. Previous efforts have shown significant dose enhancement using the proton boron fusion reaction; the overarching purpose of this work is an attempt to validate previous Monte Carlo results of the proton boron fusion reaction. Methods: The proton boron fusion reaction, 11B(p, 3α), is investigated using MCNP6 to assess the viability for potential use in radiation therapy. Simple simulations of a proton pencil beam incident upon both a water phantom and a water phantom with an axial region containing 100ppm boron were modeled using MCNP6 in order to determine the extent of the impact boron had upon the calculated energy deposition. Results: The maximum dose increase calculated was 0.026% for the incident 250 MeV proton beam scenario. The MCNP simulations performed demonstrated that the proton boron fusion reaction rate at clinically relevant boron concentrations was too small in order to have any measurable impact on the absorbed dose. Conclusion: For all MCNP6 simulations conducted, the increase of absorbed dose of a simple water phantom due to the 11B(p, 3α) reaction was found to be inconsequential. In addition, it was determined that there are no good evaluations of the 11B(p, 3α) reaction for use in MCNPX/6 and further work should be conducted in cross section evaluations in order to definitively evaluate the feasibility of the proton boron fusion reaction for use in radiation therapy applications.

  4. Application of spin-polarized fuel to fusion reactions

    International Nuclear Information System (INIS)

    Wakuta, Y.; Nakao, Y.; Honda, T.; Honda, Y.; Nakashima, H.

    1990-01-01

    Studies on the application of the polarized fuel to the inertial fusion reaction have been carried out. It is shown that the use of the spin-polarized fuel D vector·T vector or D vector· 3 (He)vector reduces the irradiating laser power more than 50% compared with the use of the unpolarized fuel. The depolarization rate of the polarized fuel during the fusing process is found to be almost negligible. (author)

  5. Gamma-ray emission spectrum from thermonuclear fusion reactions without intrinsic broadening

    DEFF Research Database (Denmark)

    Nocente, M.; Källne, J.; Salewski, Mirko

    2015-01-01

    First principle calculations of the gamma-ray energy spectrum arising from thermonuclear reactions without intrinsic broadening in fusion plasmas are presented, extending the theoretical framework needed to interpret measurements up to the accuracy level enabled by modern high resolution instrume......First principle calculations of the gamma-ray energy spectrum arising from thermonuclear reactions without intrinsic broadening in fusion plasmas are presented, extending the theoretical framework needed to interpret measurements up to the accuracy level enabled by modern high resolution...... instruments. An analytical formula for the spectrum from Maxwellian plasmas, which extends to higher temperatures than the results previously available in the literature, has been derived and used to discuss the assumptions and limitations of earlier models. In case of radio-frequency injection, numerical...... results based on a Monte Carlo method are provided, focusing in particular on improved relations between the peak shift and width from the reaction and the temperature of protons accelerated by radio-frequency heating.The results presented in this paper significantly improve the accuracy of diagnostic...

  6. Effect of breakup on near barrier fusion

    International Nuclear Information System (INIS)

    Dasgupta, M.; Berriman, A.C.; Butt, R.D.; Hinde, D.J.; Morton, C.R.; Newton, J.O.

    2000-01-01

    Full text: Unstable neutron-rich nuclei having very weakly bound neutrons exhibit characteristic features such as a neutron halo extending to large radii, and a low energy threshold for breakup. These features may dramatically affect fusion and other reaction processes. It is well accepted that the extended nuclear matter distribution will lead to an enhancement in fusion cross-sections over those for tightly bound nuclei. The effect of couplings to channels which act as doorways to breakup is, however, controversial, with model predictions differing in the relative magnitudes of enhancement and suppression. To investigate the effect on fusion of couplings specific to unstable neutron-rich nuclei, it is necessary to understand (and then predict) the cross-sections expected for their stable counterparts. This requires knowledge of the energy of the average fusion barrier, and information on the couplings. Experimentally all this information can be obtained from precisely measured fusion cross-sections. Such precision measurements of complete fusion cross-sections for 9 Be + 208 Pb and 6 Li, 7 Li + 209 Bi systems have been done at the Australian National University. The distribution of fusion barriers extracted from these data were used to reliably predict the expected fusion cross-sections. Comparison of the theoretical expectations with the experimentally measured cross-sections show conclusively that complete fusion, at above barrier energies, for all three systems is suppressed (by about 30%) compared with the fusion of more tightly bound nuclei. These measurements, in conjunction with incomplete fusion cross-sections, which were also measured, should encourage a complete theoretical description of fusion and breakup

  7. Some introductory notes on the problem of nuclear energy by controlled fusion reactions

    International Nuclear Information System (INIS)

    Pedretti, E.

    1988-01-01

    Written for scientists and technologist interested in, but unfamiliar with nuclear energy by controlled fusion reactions, this ''sui generis'' review paper attempts to provide the reader, as shortly as possible, with a general idea of the main issues at stake in nuclear fusion research. With the purpose of keeping this paper within a reasonable length, the various subjects are only outlined in their essence, basic features, underlying principles, etc., without entering into details, which are left to the quoted literature. Due to the particular readership of this journal, vacuum problems and/or aspects of fusion research anyhow related with vacuum science and technology are evidentiated. After reviewing fusion reactions' cross sections, fusion by accelerators and muon catalyzed fusion are described, followed by mention of Lawson's criteria and of plasma confinement features. Then, inertial confinement fusion is dealt with, also including one example of laser system (Nova), one of accelerator facility (PBFA-II) and some guesses on the classified Centurion-Halite program. Magnetic confinement fusion research is also reviewed, in particulary reporting one example of linear machine (MFTF-B), two examples of toroidal machines other than Tokamak (ATF and Eta-Beta-II) and various examples of Tokamaks, including PBX and PBX-M; TFTR, JET, JT-60, T-15 and Tore-Supra (large machines); Alcator A, FT, Alcator C/MTX, Alcator C-Mod and T-14 (compact high field machines). Tokamaks under design for ignition experiments (Ignitor, CIT, Ignitex and NET) are also illustrated. Thermal conversion of fusion power and direct generation of electricity are mentioned; conceptual design of fusion power plants are considered and illustrated by four examples (STARFIRE, WILDCAT, MARS and CASCADE). The D 3 He fuel cycle is discussed as an alternative more acceptable than Deuterium-Tritium, and thw Candor proposal is reported. After recalling past experience of the fission power development, some

  8. Formation, separation and detection of evaporation residues produced in complete fusion reactions

    CERN Document Server

    Sagaidak, R N

    2015-01-01

    Some aspects of formation, separation and detection of evaporation residues (ERs) produced in complete fusion reactions induced by accelerated heavy ions are considered. These reactions allow to obtain heavy neutron-deficient nuclei and to study their properties. The statistical model analysis of the production cross sections for these nuclei obtained in a wide range of their neutron numbers allows to trace the changes in their macroscopic properties such as fission barriers. The fusion probability of massive projectile and target nuclei is of interest. Empirical estimates of this value allow to verify the predictions of theoretical models for the optimal ways of synthesis of unknown nuclei. Some peculiarities in the separation and detection of ERs in experiments are briefly considered by the example of the Ra ERs produced in the 12 C+Pb reactions. The reliable cross sections for ERs produced in very asymmetric projectile-target combination, such as 12 C+Pb, are important for the em...

  9. Effects of breakup of weakly bound projectile and neutron transfer on fusion reactions around Coulomb barrier

    International Nuclear Information System (INIS)

    Lin, C.J.; Zhang, H.Q.; Yang, F.; Ruan, M.; Liu, Z.H.; Wu, Y.W.; Wu, X.K.; Zhou, P.; Zhang, C.L.; Zhang, G.L.; An, G.P.; Jia, H.M.; Xu, X.X.

    2007-01-01

    The excitation functions of quasielastic and elastic scattering at backward angles have been measured for the systems of 16 O+ 152 Sm, 6,7 Li+ 208 Pb and 32 S+ 90,96 Zr. The barrier distributions are extracted from these measured excitation functions and compared with the corresponding fusion barrier distributions. Except some details, the barrier distributions derived from the data of fusion and quasielastic/elastic scattering are almost the same for the tightly bound reaction systems. For the reaction systems with weakly bound projectile, the barrier distributions extracted from quasielastic scattering are obviously different from the fusion barrier distributions. However, the barrier distributions extracted from the excitation functions of the quasielastic scattering plus breakup are almost the same as the one extracted from the complete fusion data. This result means that barrier distribution not only bears the information of nuclear structures but also contains the knowledge of reaction mechanisms. Our results show that the complete fusion of the weakly bound projectile with heavy target is suppressed at the above barrier energies as compared with the model predictions. In addition, the measured barrier distribution of 32 S+ 96 Zr is broaden and extends to lower energy than in the case of 32 S+ 90 Zr due to the coupling of neutron transfer with positive Q-values, which result in a significant enhancement of fusion cross sections at the subbarrier energies

  10. Fusion reaction spectra produced by anisotropic fast ions in the PLT tokamak

    International Nuclear Information System (INIS)

    Heidbrink, W.W.

    1984-02-01

    For beam-target fusion reactions, collimated measurements of the energy spectrum of one of the reaction products can provide information on the degree of anisotropy of the reacting beam ions. Measurements of the spectrum of 15 MeV protons produced by reactions between energetic 3 He ions and relatively cold deuterons during fast wave minority heating in the PLT tokamak indicate that the velocity distribution of fast 3 He ions is peaked perpendicular to the tokamak magnetic field

  11. Evaluation of early tissue reactions after lumbar intertransverse process fusion using CT in a rabbit

    International Nuclear Information System (INIS)

    Shinbo, Jun; Mainil-Varlet, Pierre; Watanabe, Atsuya; Pippig, Suzanne; Koener, Jens; Anderson, Suzanne E.

    2010-01-01

    The objective of the study was to evaluate tissue reactions such as bone genesis, cartilage genesis and graft materials in the early phase of lumbar intertransverse process fusion in a rabbit model using computed tomography (CT) imaging with CT intensity (Hounsfield units) measurement, and to compare these data with histological results. Lumbar intertransverse process fusion was performed on 18 rabbits. Four graft materials were used: autograft bone (n=3); collagen membrane soaked with recombinant human bone morphogenetic protein-2 (rhBMP-2) (n=5); granular calcium phosphate (n=5); and granular calcium phosphate coated with rhBMP-2 (n=5). All rabbits were euthanized 3 weeks post-operatively and lumbar spines were removed for CT imaging and histological examination. Computed tomography imaging demonstrated that each fusion mass component had the appropriate CT intensity range. CT also showed the different distributions and intensities of bone genesis in the fusion masses between the groups. Each component of tissue reactions was identified successfully on CT images using the CT intensity difference. Using CT color mapping, these observations could be easily visualized, and the results correlated well with histological findings. The use of CT intensity is an effective approach for observing and comparing early tissue reactions such as newly synthesized bone, newly synthesized cartilage, and graft materials after lumbar intertransverse process fusion in a rabbit model. (orig.)

  12. Fusion cross-sections of 16O+16O reaction in pseudonucleon picture

    International Nuclear Information System (INIS)

    Mishra, R.C.; Waghmare, Y.R.

    1991-01-01

    Fusion cross-sections for 16 O+ 16 O reaction are calculated in classical equations of motion approach using the pseudonucleon picture. These calculated fusion cross-sections are very close to measured values than earlier calculated using the same NN interaction. The aim of the paper is to test the pseudonucleon picture. Use of this picture does not require one to consider the number of relative random orientations of the colliding clusters. (author). 22 refs., 2 tabs., 4 figs

  13. A CASE OF LOWER ANTERIOR PRIMARY TEETH FUSION

    Directory of Open Access Journals (Sweden)

    Noni Nurseni

    2006-04-01

    Full Text Available Dental fusion is the most common problem seen in the primary dentition. The incidence of dental fusion was approximately 0.5% for deciduous dentition and 0.1% for permanent dentition. Fusion may be complete or incomplete. Its etiology was related to genetic or local factor. These anomalies could result in dental caries, esthetic problem, periodontal disease, dental malocclusion, and hypodontia in permanent dentition. Treatment of fused teeth depends on the location and extent of fusion. This report describes an incomplete dental fusion with dentinal caries occurred on 72 and 73 while 32 was agenesis. The purpose of the treatment was to improve the esthetic performance and subsequently to keep the teeth until the exfoliation time. After the restoration of 72 and 73, the patient feels satisfied.

  14. Multi-Sampling Ionization Chamber (MUSIC) for measurements of fusion reactions with radioactive beams

    International Nuclear Information System (INIS)

    Carnelli, P.F.F.; Almaraz-Calderon, S.; Rehm, K.E.; Albers, M.; Alcorta, M.; Bertone, P.F.; Digiovine, B.; Esbensen, H.; Fernández Niello, J.; Henderson, D.; Jiang, C.L.; Lai, J.; Marley, S.T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R.C.; Paul, M.; Ugalde, C.

    2015-01-01

    A detection technique for high-efficiency measurements of fusion reactions with low-intensity radioactive beams was developed. The technique is based on a Multi-Sampling Ionization Chamber (MUSIC) operating as an active target and detection system, where the ionization gas acts as both target and counting gas. In this way, we can sample an excitation function in an energy range determined by the gas pressure, without changing the beam energy. The detector provides internal normalization to the incident beam and drastically reduces the measuring time. In a first experiment we tested the performance of the technique by measuring the 10,13,15 C+ 12 C fusion reactions at energies around the Coulomb barrier

  15. Multi-Sampling Ionization Chamber (MUSIC) for measurements of fusion reactions with radioactive beams

    Energy Technology Data Exchange (ETDEWEB)

    Carnelli, P.F.F. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, B1650KNA, San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Almaraz-Calderon, S. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Rehm, K.E., E-mail: rehm@anl.gov [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Albers, M.; Alcorta, M.; Bertone, P.F.; Digiovine, B.; Esbensen, H. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Fernández Niello, J. [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, B1650KNA, San Martín, Buenos Aires (Argentina); Universidad Nacional de San Martín, Campus Miguelete, B1650BWA San Martín, Buenos Aires (Argentina); Henderson, D.; Jiang, C.L. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Lai, J. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Marley, S.T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R.C. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Paul, M. [Racah Institute of Physics, Hebrew University, Jerusalem (Israel); Ugalde, C. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2015-11-01

    A detection technique for high-efficiency measurements of fusion reactions with low-intensity radioactive beams was developed. The technique is based on a Multi-Sampling Ionization Chamber (MUSIC) operating as an active target and detection system, where the ionization gas acts as both target and counting gas. In this way, we can sample an excitation function in an energy range determined by the gas pressure, without changing the beam energy. The detector provides internal normalization to the incident beam and drastically reduces the measuring time. In a first experiment we tested the performance of the technique by measuring the {sup 10,13,15}C+{sup 12}C fusion reactions at energies around the Coulomb barrier.

  16. Role of hexadecapole deformation of projectile 28Si in heavy-ion fusion reactions near the Coulomb barrier

    Science.gov (United States)

    Kaur, Gurpreet; Hagino, K.; Rowley, N.

    2018-06-01

    The vast knowledge regarding the strong influence of quadrupole deformation β2 of colliding nuclei in heavy-ion sub-barrier fusion reactions inspires a desire to quest the sensitivity of fusion dynamics to higher order deformations, such as β4 and β6 deformations. However, such studies have rarely been carried out, especially for deformation of projectile nuclei. In this article, we investigated the role of β4 of the projectile nucleus in the fusion of the 28Si+92Zr system. We demonstrated that the fusion barrier distribution is sensitive to the sign and value of the β4 parameter of the projectile, 28Si, and confirmed that the 28Si nucleus has a large positive β4. This study opens an indirect way to estimate deformation parameters of radioactive nuclei using fusion reactions, which is otherwise difficult because of experimental constraints.

  17. Elastic scattering and fusion studies in the reactions $^{10,11}$Be + $^{64}$Zn

    CERN Multimedia

    2002-01-01

    We propose to measure elastic scattering and fusion excitation functions for the reactions $^{10,11}$Be + $^{64}$Zn at 3.1 MeV/u . The aim of the experiment is to investigate possible effects of the halo structure of the $^{11}$Be nucleus on the reaction mechanisms at energy around the Coulomb barrier. For this purpose a comparison with the reaction induced by the $^{10}$Be nucleus is required.

  18. Application of the high-spin isomer beams to the secondary fusion reaction and the measurement of g-factor

    International Nuclear Information System (INIS)

    Watanabe, H.; Asahi, K.; Kishida, T.; Ueno, H.; Sato, W.; Yoshimi, A.; Kobayashi, Y.; Kameda, D.; Miyoshi, H.; Fukuchi, T.; Wakabayashi, Y.; Sasaki, T.; Kibe, M.; Hokoiwa, N.; Odahara, A.; Cederwall, B.; Lagergren, K.; Podolyak, Zs.; Ishihara, M.; Gono, Y.

    2004-01-01

    A technique for providing high-spin isomers as probes of the fusion reaction and the measurement of g-factor has been worked out at RIKEN. In the study of the fusion reaction 12 C( 145m Sm,xn) 157-x Er, the γ rays emitted from the fusion-evaporation residue 154 Er have been successfully observed. The nuclear g-factor of the T 1/2 = 28 ns high-spin isomer in 149 Dy has been measured with the γ-ray TDPAD method

  19. Semi-exclusive study of the reaction 40Ar + 197Au at 35 MeV/u. Comparison with a participant-spectator model

    International Nuclear Information System (INIS)

    Harasse, J.M.

    1986-07-01

    The Ar+Au reaction has been studied at the GANIL accelerator at 35 MeV per nucleon. Target like nuclei and complete and incomplete fusion residues were detected by a time of flight telescope composed of solid detectors. Fission products were detected in coincidence, one of them by the time of flight telescope and the second one in a position sensitive parallel plate avalanche counter. Forward emitted light nuclei were detected (in the angular range 3 0 -30 0 ) in coincidence either with a heavy residue or with two fission products by a multidetector constituted of 96 thin scintillator sheets allowing charge identification. The main results are the following: the residue velocity spectrum increases monotonically toward small velocities: the incomplete fusion bump still present in the residue velocity spectrum of the same reaction at 27 MeV/A has desappeared; the fission products angular correlation exhibits two peaks of similar amplitudes: the first one is linked to peripheral interactions, the second one to incomplete fusion. The heavy residues characteristics (mass, angle, velocity) are compatible with the predictions of a participant spectator model including reabsorption in the target of some of the participant nucleons (Bondorf model). However, the comparison between the experimental and predicted light particle velocity spectra allows to exclude the existence of an autonous participant zone. 29 refs [fr

  20. Hot nuclei production and deexcitation in heavy ions induced reactions on medium mass targets in the 10-84 MeV/nucleon energy domain

    International Nuclear Information System (INIS)

    Lleres, A.

    1988-01-01

    Velocity, angular distributions and total cross sections for heavy residues produced in the reactions 12 C, 14 N, 20 Ne, 40 Ar + 124 Sn have been measured in the 10-84 MeV/nucleon incident energy range using catchers technique in association with off-line gamma-activity spectroscopy. The observed reaction products are interpreted as evaporation residues from equilibrated systems formed by complete or incomplete fusion of the projectile and target nuclei. From the velocities and residual masses measured at forward angles, the linear momentum transfers and excitation energies associated with the intermediate systems are estimated using simple fusion-evaporation models and are next compared to the predictions of the preequilibrium and Fermi jets models. Energy, angular, charge and charge correlation distributions for intermediate mass fragments emitted in the reaction 32 S + nat Ag at 30 MeV/nucleon were also measured using gaseous and silicon detectors. The energy and angular distributions indicate that both equilibrated and non-equilibrated emitting sources are present. The equilibrium emission is attributed to the deexcitation of systems produced by incomplete fusion of the projectile and target nuclei. The charge correlation distributions are consistent with an asymmetric fission decay process. The linear momentum transfer and excitation energy associated with the equilibrated source are estimated using a simple fusion-fission model [fr

  1. Estimation of the {alpha} particles and neutron distribution generated during a fusion reaction; Evaluation de la distribution des particules {alpha} et des neutrons issus de la reaction de fusion

    Energy Technology Data Exchange (ETDEWEB)

    Dellacherie, S.

    1997-12-01

    The respective distributions (or density probabilities) of {alpha} particles and neutrons have been modeled using a Monte-Carlo method for the thermonuclear fusion reaction D + T {yields} {alpha} + n + 17.6 MeV. (N.T.).

  2. Achievement of solid-state plasma fusion ('Cold-Fusion')

    International Nuclear Information System (INIS)

    Arata, Yoshiaki; Zhang, Yue-Chang

    1995-01-01

    Using a 'QMS' (Quadrupole Mass Spectrometer), the authors detected a significantly large amount (10 20 -10 21 [cm -3 ]) of helium ( 2 4 He), which was concluded to have been produced by a deuterium nuclear reaction within a host solid. These results were found to be fully repeatable and supported the authors' proposition that solid state plasma fusion ('Cold Fusion') can be generated in energetic deuterium Strongly Coupled Plasma ('SC-plasma'). This fusion reaction is thought to be sustained by localized 'Latticequake' in a solid-state media with the deuterium density equivalent to that of the host solid. While exploring this basic proposition, the characteristic differences when compared with ultra high temperature-state plasma fusion ('Hot Fusion') are clarified. In general, the most essential reaction product in both types of the deuterium plasma fusion is considered to be helium, irrespective of the 'well-known and/or unknown reactions', which is stored within the solid-state medium in abundance as a 'Residual Product', but which generally can not enter into nor be released from host-solid at a room temperature. Even measuring instruments with relatively poor sensitivity should be able to easily detect such residual helium. An absence of residual helium means that no nuclear fusion reaction has occurred, whereas its presence provides crucial evidence that nuclear fusion has, in fact, occurred in the solid. (author)

  3. A classical approach in simple nuclear fusion reaction 1H2+1H3 using two-dimension granular molecular dynamics model

    International Nuclear Information System (INIS)

    Viridi, S.; Kurniadi, R.; Waris, A.; Perkasa, Y. S.

    2012-01-01

    Molecular dynamics in 2-D accompanied by granular model provides an opportunity to investigate binding between nuclei particles and its properties that arises during collision in a fusion reaction. A fully classical approach is used to observe the influence of initial angle of nucleus orientation to the product yielded by the reaction. As an example, a simplest fusion reaction between 1 H 2 and 1 H 3 is observed. Several products of the fusion reaction have been obtained, even the unreported ones, including temporary 2 He 4 nucleus.

  4. Fusion measurements in light and medium mass heavy-ion reactions. Progress report, June 1, 1980-May 31, 1981

    International Nuclear Information System (INIS)

    Prosser, F.W.

    1981-01-01

    The data obtained for fusion residues from the 16 18 O + 24 26 Mg systems have been analyzed and are being compared to each other and to predictions from the fusion-evaporation code CASCADE. Analysis of data obtained for a small step excitation curve for the 16 O + 24 Mg system has been started to determine the possible presence of structure in the fusion cross section. Additional data for the fusion cross sections of these systems have been obtained at energies from 100 to 140 MeV at the ATLAS facility and are being analyzed. Initial measurements of the fusion-fission cross sections for 58 Ni beams, at energies up to 320 MeV on targets from 116 Sn to 170 Yb have been made. Analysis is in progress and additional experiments are planned. A collaboration is planned at Notre Dame for experiments to determine the entry line for fusion in the 12 C + 16 O system, both for the interest in this system and for preparation for additional experiments at higher energies at Michigan State when the new facility there becomes available. These experiments should lead to information about the importance of incomplete fusion in this system. Experiments to test the limitation on fusion cross sections predicted by the rotating liquid drop model are planned as higher energies become available at ATLAS and MSU

  5. Pulsed fusion space propulsion: Computational Magneto-Hydro Dynamics of a multi-coil parabolic reaction chamber

    Science.gov (United States)

    Romanelli, Gherardo; Mignone, Andrea; Cervone, Angelo

    2017-10-01

    Pulsed fusion propulsion might finally revolutionise manned space exploration by providing an affordable and relatively fast access to interplanetary destinations. However, such systems are still in an early development phase and one of the key areas requiring further investigations is the operation of the magnetic nozzle, the device meant to exploit the fusion energy and generate thrust. One of the last pulsed fusion magnetic nozzle design is the so called multi-coil parabolic reaction chamber: the reaction is thereby ignited at the focus of an open parabolic chamber, enclosed by a series of coaxial superconducting coils that apply a magnetic field. The field, beside confining the reaction and preventing any contact between hot fusion plasma and chamber structure, is also meant to reflect the explosion and push plasma out of the rocket. Reflection is attained thanks to electric currents induced in conductive skin layers that cover each of the coils, the change of plasma axial momentum generates thrust in reaction. This working principle has yet to be extensively verified and computational Magneto-Hydro Dynamics (MHD) is a viable option to achieve that. This work is one of the first detailed ideal-MHD analysis of a multi-coil parabolic reaction chamber of this kind and has been completed employing PLUTO, a freely distributed computational code developed at the Physics Department of the University of Turin. The results are thus a preliminary verification of the chamber's performance. Nonetheless, plasma leakage through the chamber structure has been highlighted. Therefore, further investigations are required to validate the chamber design. Implementing a more accurate physical model (e.g. Hall-MHD or relativistic-MHD) is thus mandatory, and PLUTO shows the capabilities to achieve that.

  6. Some thoughts on a simple mechanism for the 2H + 2H → 4He cold fusion reaction

    International Nuclear Information System (INIS)

    Park, A.E.

    1993-01-01

    A speculative mechanism for the creation of 4 He using cold fusion is proposed. The nuclear transformation can be made by the fusion of two excited rotating ground states of deuterium into a highly excited rotating ground state of 4 He. Under compression and relatively stable conditions, the formation of such a bound, stretched-out pnnp state of 4 He would be favored (with respect to Coulomb repulsion) over other nuclear ground states without as much angular momentum. The reaction likely occurs at the surface of palladium. A more descriptive name for this reaction is compressed-rotational-shielded (CRS) fusion. Potential experimental conditions for enhancing the initiation of CRS fusion are discussed. 8 refs., 2 figs

  7. Quantum shielding effects on the Gamow penetration factor for nuclear fusion reaction in quantum plasmas

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2017-01-01

    The quantum shielding effects on the nuclear fusion reaction process are investigated in quantum plasmas. The closed expression of the classical turning point for the Gamow penetration factor in quantum plasmas is obtained by the Lambert W-function. The closed expressions of the Gamow penetration factor and the cross section for the nuclear fusion reaction in quantum plasmas are obtained as functions of the plasmon energy and the relative kinetic energy by using the effective interaction potential with the WKB analysis. It is shown that the influence of quantum screening suppresses the Sommerfeld reaction factor. It is also shown that the Gamow penetration factor increases with an increase of the plasmon energy. It is also shown that the quantum shielding effect enhances the deuterium formation by the proton-proton reaction in quantum plasmas. In addition, it is found that the energy dependences on the reaction cross section and the Gamow penetration factor are more significant in high plasmon-energy domains.

  8. Collinear laser spectroscopy on In isotopes from heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Ulm, G.

    1984-07-01

    Indium isotopes 107-111 were produced by 16 O-fusion reactions and investigated in a collinear laser geometry. The hyperfine structure and isotopic shifts are measured and the deduced magnetic dipole moments are in agreement with shell model calculations. The nuclear charge radii are determined from the isotopic shifts. (WL)

  9. Smooth transition from sudden to adiabatic states in heavy-ion fusion reactions at deep-subbarrier incident energies

    International Nuclear Information System (INIS)

    Takatoshi, Ichikawa; Kouichi, Hagino; Akira, Iwamoto

    2011-01-01

    We propose a novel extension of the standard coupled-channel (CC) model in order to account for the steep falloff of fusion cross sections at deep-subbarrier incident energies. We introduce a damping factor in the coupling potential in the CC model, simulating smooth transitions from sudden to adiabatic states in deep- subbarrier fusion reactions. The CC model extended with the damping factor can reproduce well not only the steep falloff of the fusion cross section but also the saturation of the logarithmic derivatives for the fusion cross sections at deep-subbarrier energies for the 16 O+ 208 Pb, 64 Ni+ 64 Ni, and 58 Ni+ 58 Ni reactions at the deep-subbarrier energies. The important point in our model is that the transition takes place at different places for each Eigen channel. We conclude that the smooth transition from the two-body to the adiabatic one-body potential is responsible for the steep falloff of the fusion cross section

  10. Classical molecular dynamics simulation of weakly-bound projectile heavy-ion reactions

    Directory of Open Access Journals (Sweden)

    Morker Mitul R.

    2015-01-01

    Full Text Available A 3-body classical molecular dynamics approach for heavy-ion reactions involving weakly bound projectiles is developed. In this approach a weakly bound projectile is constructed as a two-body cluster of the constituent tightly bound nuclei in a configuration corresponding to the observed breakup energy. This 3-body system with their individual nucleon configuration in their ground state is dynamically evolved for given initial conditions using the three-stage classical molecular dynamics approach (3S-CMD. Various levels of rigidbody constraints on the projectile constituents and the target are considered at appropriate stages. This 3-dimensional approach explicitly takes into account not only the long range Coulomb reorientation of the deformed collision partner but internal excitations and breakup probabilities at distances close to the barrier also. Dynamical simulations of 6Li+209Bi show all the possible reaction mechanism like complete fusion, incomplete fusion, scattering and breakup scattering. Complete fusion cross sections of 6Li+209Bi and 7Li+209Bi reactions are calculated in this approach with systematic relaxations of the rigid-body constraints on one or more constituent nuclei.

  11. Fusion and direct reactions for strongly and weakly bound projectiles

    International Nuclear Information System (INIS)

    Hugi, M.; Lang, J.; Mueller, R.; Ungricht, E.; Bodek, K.; Jarczyk, L.; Kamys, B.; Magiera, A.; Strzalkowski, A.; Willim, G.

    1981-01-01

    The interaction of 6 Li, 9 Be and 12 C projectiles with a 28 Si target was investigated by measuring the angular distributions of the elasitcally scattered projectiles and of the emitted protons, deuterons and α-particles. The experiment was perfomred in order to deduce direct and compound nucleus process contributions to the total reaction cross section and to study the influence of the projectile structure on the relative importance of these two mechanisms. Optical model parameters and therefore the total reaction cross section are strongly influenced by the binding energy of the projectile. The parameters of the Glas-Mosel describing the fusion reaction vary smoothly with the atomic number. In the system 9 B + 28 Si around 50% of all reactions are direct processes even at energies near the Coulomb barrier, whereas in the other systeme the direct part amounts to 15% ( 12 C) and 30% ( 6 Li) only. (orig.)

  12. Fusion dynamics of 2020Ne + 20882Pb reaction using static and energy dependent Woods-Saxon potential

    International Nuclear Information System (INIS)

    Gautam, Manjeet Singh; Kaur, Amandeep; Sharma, Manoj K.

    2015-01-01

    The present work compares the theoretical predictions based on static Woods-Saxon potential and the EDWSP model along with one dimensional Wong formula. For 20 20 Ne + 208 82 Pb reaction, the theoretical calculations obtained by using static Woods-Saxon potential are substantially smaller than that of experimental data at below barrier energies and explain the fusion data at above barrier energies only. On the other hand, the EDWSP model based calculations adequately describe the observed fusion enhancement of 20 20 Ne + 208 82 Pb reaction in whole range of energy spread across the Coulomb barrier. Furthermore, a wide range of the diffuseness parameter ranging from 0.96 fm to 0.85 fm is required to address the sub-barrier fusion data

  13. Fusion and quasifission studies for the 40Ca+186W,192Os reactions

    Science.gov (United States)

    Prasad, E.; Hinde, D. J.; Williams, E.; Dasgupta, M.; Carter, I. P.; Cook, K. J.; Jeung, D. Y.; Luong, D. H.; Palshetkar, C. S.; Rafferty, D. C.; Ramachandran, K.; Simenel, C.; Wakhle, A.

    2017-09-01

    Background: All elements above atomic number 113 have been synthesized using hot fusion reactions with calcium beams on statically deformed actinide target nuclei. Quasifission and fusion-fission are the two major mechanisms responsible for the very low production cross sections of superheavy elements. Purpose: To achieve a quantitative measurement of capture and quasifission characteristics as a function of beam energy in reactions forming heavy compound systems using calcium beams as projectiles. Methods: Fission fragment mass-angle distributions were measured for the two reactions 40Ca+186W and 40C+192Os, populating 226Pu and 232Cm compound nuclei, respectively, using the Heavy Ion Accelerator Facility and CUBE spectrometer at the Australian National University. Mass ratio distributions, angular distributions, and total fission cross sections were obtained from the experimental data. Simulations to match the features of the experimental mass-angle distributions were performed using a classical phenomenological approach. Results: Both 40Ca+186W and 40C+192Os reactions show strong mass-angle correlations at all energies measured. A maximum fusion probability of 60 -70 % is estimated for the two reactions in the energy range of the present study. Coupled-channels calculations assuming standard Woods-Saxon potential parameters overpredict the capture cross sections. Large nuclear potential diffuseness parameters ˜1.5 fm are required to fit the total capture cross sections. The presence of a weak mass-asymmetric quasifission component attributed to the higher angular momentum events can be reproduced with a shorter average sticking time but longer mass-equilibration time constant. Conclusions: The deduced above-barrier capture cross sections suggest that the dissipative processes are already occurring outside the capture barrier. The mass-angle correlations indicate that a compact shape is not achieved for deformation aligned collisions with lower capture barriers

  14. Fusability and fissionability in 86Kr induced reactions near and below the fusion barrier

    International Nuclear Information System (INIS)

    Reisdorf, W.; Hessberger, F.P.; Hildenbrand, K.D.; Hofmann, S.; Muenzenberg, G.; Schmidt, K.H.; Schneider, W.F.W.; Suemmerer, K.; Wirth, G.; Kratz, J.V.; Schlitt, K.; Sahm, C.C.

    1985-04-01

    Evaporation-residue excitation functions for the reactions 86 Kr + sup(70,76)Ge, sup(92,100)Mo, sup(99,102,104)Ru have been measured using activation methods and the velocity filter SHIP. The data span the region from well below the fusion barrier up to and beyond the energy where limitation by fission competition takes place. The data are shown to be compatible with the concept of complete fusion followed by the statistical decay of the equilibrated compound nucleus. Information on both the fusion probability at and below the fusion threshold and the fissionability of the compound nuclei formed is extracted. The model dependence of the extracted fission barriers is discussed in detail. In analogy to studies involving lighter projectiles, strong correlations between the low-energy nuclear-structure properties of the nuclei and the subbarrier fusion probability are found. A relative shift of the fusion barrier to higher energies, that increases with the number of valence neutrons in the target nuclei, is observed. (orig.)

  15. Heavy residues from very mass asymmetric heavy ion reactions

    International Nuclear Information System (INIS)

    Hanold, K.A.

    1994-08-01

    The isotopic production cross sections and momenta of all residues with nuclear charge (Z) greater than 39 from the reaction of 26, 40, and 50 MeV/nucleon 129 Xe + Be, C, and Al were measured. The isotopic cross sections, the momentum distribution for each isotope, and the cross section as a function of nuclear charge and momentum are presented here. The new cross sections are consistent with previous measurements of the cross sections from similar reaction systems. The shape of the cross section distribution, when considered as a function of Z and velocity, was found to be qualitatively consistent with that expected from an incomplete fusion reaction mechanism. An incomplete fusion model coupled to a statistical decay model is able to reproduce many features of these reactions: the shapes of the elemental cross section distributions, the emission velocity distributions for the intermediate mass fragments, and the Z versus velocity distributions. This model gives a less satisfactory prediction of the momentum distribution for each isotope. A very different model based on the Boltzman-Nordheim-Vlasov equation and which was also coupled to a statistical decay model reproduces many features of these reactions: the shapes of the elemental cross section distributions, the intermediate mass fragment emission velocity distributions, and the Z versus momentum distributions. Both model calculations over-estimate the average mass for each element by two mass units and underestimate the isotopic and isobaric widths of the experimental distributions. It is shown that the predicted average mass for each element can be brought into agreement with the data by small, but systematic, variation of the particle emission barriers used in the statistical model. The predicted isotopic and isobaric widths of the cross section distributions can not be brought into agreement with the experimental data using reasonable parameters for the statistical model

  16. The extended sum-rule model view of light and intermediate mass fragment emission in nuclear reactions at intermediate energies

    International Nuclear Information System (INIS)

    Brancus, I.M.; Rebel, H.; Wentz, J.; Corcalciuc, V.

    1989-11-01

    The original sum-rule model worked out by Wilczynski et al. and successfully used for a global description of complete and incomplete fusion reactions has been extended by a term accounting for dissipative processes of the dinuclear system on its way to fusion. When applying to light and heavy ion collisions with various targets at energies in the transitional region, the new term proves to be rather essential for reproducing the element distributions of the fragments emitted from rather asymmetric systems. (orig.) [de

  17. Investigation of incomplete fusion dynamics by measurement of excitation functions in the 20Ne + 59Co system

    International Nuclear Information System (INIS)

    Singh, D.; Linda, Sneha Bharti; Giri, Pankaj K.; Singh, Smita Shree; Kumar, Harish; Afzal Ansari, M.; Ali, Rahbar; Rashid, M.H.; Guin, R.; Das, S.K.

    2015-01-01

    In the present work, an attempt has been made to address some important aspects of CF and ICF dynamics for the system 20 Ne + 59 Co in the projectile energy range ≈ 62–150 MeV by using recoil catcher activation technique with the following off-line γ-ray spectroscopy. Excitation Functions (EFs) for the following reactions: 59 Co(Ne, α p4n) 70 Ga, 59 Co(Ne, 3αp3n) 63 Zn, 59 Co (Ne, 3αp4n) 62 Zn and 59 Co (Ne, 4α3n) 60 Cu have been measured. No precursor decay contribution has been observed for these measured evaporation residues. The measured values of total fusion cross-sections of the above evaporation residues have been compared with the theoretical total complete fusion cross sections calculated by code PACE-2, which do not take into account ICF contribution

  18. Research in theoretical nuclear physics

    International Nuclear Information System (INIS)

    Udagawa, T.

    1993-11-01

    This report describes the accomplishments in basic research in nuclear physics carried out by the theoretical nuclear physics group in the Department of Physics at the University of Texas at Austin, during the period of November 1, 1992 to October 31, 1993. The work done covers three separate areas, low-energy nuclear reactions, intermediate energy physics, and nuclear structure studies. Although the subjects are thus spread among different areas, they are based on two techniques developed in previous years. These techniques are a powerful method for continuum-random-phase-approximation (CRPA) calculations of nuclear response and the breakup-fusion (BF) approach to incomplete fusion reactions, which calculation on a single footing of various incomplete fusion reaction cross sections within the framework of direct reaction theories. The approach was developed as a part of a more general program for establishing an approach to describing all different types of nuclear reactions, i.e., complete fusion, incomplete fusion and direct reactions, in a systematic way based on single theoretical framework

  19. Sources and characteristics of complex fragments in La-induced reactions

    International Nuclear Information System (INIS)

    Roussel-Chomaz, P.; Blumenfeld, Y.; Charity, R.; Colonna, M.; Colonna, N.; Libby, B.; Hanold, K.; Moretto, L.; Peaslee, G.; Wozniak, G.

    1991-01-01

    Complex fragment emission has been studied for a variety of reactions at intermediate energies. Multifragment events are shown to be associated with specific sources characterized by their mass and excitation energy through the incomplete fusion model. Excitation functions for the different multifragment decay channels are found to be almost independent of the system and the incident energy. Preliminary comparisons of the data with dynamical calculations followed by statistical decay calculations are discussed. 11 refs., 7 figs

  20. Effects on nuclear fusion reaction on diffusion and thermal conduction in a magnetoplasma

    International Nuclear Information System (INIS)

    Sakai, Kazuo; Aono, Osamu.

    1976-12-01

    In spite of the well spread belief in the field of irreversible thermodynamics, vectorial phenomena couple thermodynamically with the scalar phenomena. Transport coefficients concerning the diffusion and the thermal conduction across a strong magnetic field are calculated in the presence of the deuteron-triton fusion reaction on the basis of the gas kinetic theory. When the reaction takes place, the diffusion increases and the thermal conduction decreases. Effects of the reaction exceed those of the Coulomb collision as the temperature is high enough. (auth.)

  1. Interobserver agreement in fusion status assessment after instrumental desis of the lower lumbar spine using 64-slice multidetector computed tomography

    DEFF Research Database (Denmark)

    Laoutliev, Borislav; Havsteen, Inger; Bech, Birthe Højlund

    2012-01-01

    Persistent lower back pain after instrumental posterolateral desis may arise from incomplete fusion. We investigate the impact of experience on interobserver agreement in fusion estimation.......Persistent lower back pain after instrumental posterolateral desis may arise from incomplete fusion. We investigate the impact of experience on interobserver agreement in fusion estimation....

  2. Study of the role of complete fusion in the reaction of 48Ca and 56Fe with cerium and terbium

    International Nuclear Information System (INIS)

    Morrissey, D.J.

    1978-05-01

    48 Ca and 56 Fe beams from the Super HILAC accelerator were used to irradiate thick metal foils of cerium and terbium. Product gamma ray activities were detected offline and individual products were identified by half-life, gamma ray energy and gamma ray abundances. The production cross sections were iteratively fit to charge and mass dispersions to allow correction for parent decay and calculation of mass yields. From the mass yield curves contributions from quasielastic transfer, deep inelastic transfer and complete fusion reaction mechanisms were interred. Complete fusion was made up on contributions from both evaporation residue and fusion-fission products for the 48 Ca induced reactions. However, only fusion-fission products were detected in the 56 Fe induced reactions. Critical angular momenta for fusion were found to be 82 +- 8 h for 48 Ca + 159 Tb and 34 +- 5 h for 56 Fe + 140 Ce, which can be compared with 53 +- 8 h for 12 C + 197 Au (Natowitz, 1970) and 86 +- 5 h for 40 Ar + 165 Ho (Hanappe, 1973). All of these reactions lead to essentially the same compound nucleus and seem to show the dramatic decline in complete fusion for heavy ions larger than 40 Ar. The prediction of this decline was found to be beyond the model calculations of Bass and the critical distance approach of Glas and Mosel

  3. Reaction-rate coefficients, high-energy ions slowing-down, and power balance in a tokamak fusion reactor plasma

    International Nuclear Information System (INIS)

    Tone, Tatsuzo

    1978-07-01

    Described are the reactivity coefficient of D-T fusion reaction, slowing-down processes of deuterons injected with high energy and 3.52 MeV alpha particles generated in D-T reaction, and the power balance in a Tokamak reactor plasma. Most of the results were obtained in the first preliminary design of JAERI Experimental Fusion Reactor (JXFR) driven with stationary neutral beam injection. A manual of numerical computation program ''BALTOK'' developed for the calculations is given in the appendix. (auth.)

  4. Application of SSNTDs for measurements of fusion reaction products in high-temperature plasma experiments

    Energy Technology Data Exchange (ETDEWEB)

    Malinowska, A., E-mail: a.malinowska@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Szydlowski, A.; Malinowski, K. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Sadowski, M.J. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Institute of Plasma Physics and Laser Microfusion (IPPLM), 00-908 Warsaw (Poland); Zebrowski, J. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Scholz, M.; Paduch, M.; Zielinska, E. [Institute of Plasma Physics and Laser Microfusion (IPPLM), 00-908 Warsaw (Poland); Jaskola, M.; Korman, A. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland)

    2009-10-15

    The paper describes the application of SSNTDs of the PM-355 type to diagnostics of reaction products emitted from high-temperature deuterium plasmas produced in Plasma Focus (PF) facilities. Acceleration processes occurring in plasma lead often to the generation of high-energy ion beams. Such beams induce nuclear reactions and contribute to the emission of fast neutrons, fusion protons and alpha particles from PF discharges with a deuterium gas. Ion measurements are of primary importance for understanding the mechanisms of the physical processes which drive the charged-particle acceleration. The main aim of the present studies was to perform measurements of spatial- and energy-distributions of fusion-reaction protons (about 3 MeV) within a PF facility. Results obtained from energy measurements were compared with the proton-energy spectra computed theoretically. The protons were measured by means of a set of ion pinhole cameras equipped with PM-355 detectors, which were placed at different angles relative to the electrode axis of the PF facility.

  5. Coupled-channels analyses for 9,11Li + 208Pb fusion reactions with multi-neutron transfer couplings

    Science.gov (United States)

    Choi, Ki-Seok; Cheoun, Myung-Ki; So, W. Y.; Hagino, K.; Kim, K. S.

    2018-05-01

    We discuss the role of two-neutron transfer processes in the fusion reaction of the 9,11Li + 208Pb systems. We first analyze the 9Li + 208Pb reaction by taking into account the coupling to the 7Li + 210Pb channel. To this end, we assume that two neutrons are directly transferred to a single effective channel in 210Pb and solve the coupled-channels equations with the two channels. By adjusting the coupling strength and the effective Q-value, we successfully reproduce the experimental fusion cross sections for this system. We then analyze the 11Li + 208Pb reaction in a similar manner, that is, by taking into account three effective channels with 11Li + 208Pb, 9Li + 210Pb, and 7Li + 212Pb partitions. In order to take into account the halo structure of the 11Li nucleus, we construct the potential between 11Li and 208Pb with a double folding procedure, while we employ a Woods-Saxon type potential with the global Akyüz-Winther parameters for the other channels. Our calculation indicates that the multiple two-neutron transfer process plays a crucial role in the 11Li + 208Pb fusion reaction at energies around the Coulomb barrier.

  6. Indirect Study of the 16O+16O Fusion Reaction Toward Stellar Energies by the Trojan Horse Method

    Directory of Open Access Journals (Sweden)

    Hayakawa S.

    2016-01-01

    Full Text Available The 16O+16O fusion reaction is important in terms of the explosive oxygen burning process during late evolution stage of massive stars as well as understanding of the mechanism of low-energy heavy-ion fusion reactions. We aim to determine the excitation function for the most major exit channels, α+28Si and p+31P, toward stellar energies indirectly by the Trojan Horse Method via the 16O(20Ne, α28Siα and 16O(20Ne, p31Pα three-body reactions. We report preliminary results involving reaction identification, and determination of the momentum distribution of α-16O intercluster motion in the projectile 20Ne nucleus.

  7. The controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Barre, Bertrand

    2014-01-01

    After some generalities on particle physics, and on fusion and fission reactions, the author outlines that the fission reaction is easier to obtain than the fusion reaction, evokes the fusion which takes place in stars, and outlines the difficulty to manage and control this reaction: one of its application is the H bomb. The challenge is therefore to find a way to control this reaction and make it a steady and continuous source of energy. The author then presents the most promising way: the magnetic confinement fusion. He evokes its main issues, the already performed experiments (tokamak), and gives a larger presentation of the ITER project. Then, he evokes another way, the inertial confinement fusion, and the two main experimental installations (National Ignition Facility in Livermore, and the Laser Megajoule in Bordeaux). Finally, he gives a list of benefits and drawbacks of an industrial nuclear fusion

  8. A comparison of the radiological impact of energy production by fission and fusion reactions

    International Nuclear Information System (INIS)

    Rancillac, F.; Despres, A.

    1990-04-01

    The impacts of respectively a light water reactor and a planned fusion reactor, for which tritium-deuterium fusion reactions will act as energy source have been compared. The comparison is made on the basis of a generated capacity of 1 GWe.year, using the following criteria: fuel inventories, radioactive releases, collective effective dose equivalent commitments to the public and the volume of wastes. The accidental risk is not introduced. Fusion reactor parameters are still subject to uncertainties, which prevent accurate quantification of radionuclide releases (tritium apart) from the nuclear plant. Only orders of magnitude extrapolated from values for the NET tokamak are given. Despite these uncertainties, it would seem more interesting, from the dosimetric point of view, to use fusion reactors to produce electricity, although problems of radioactive releases, handling and long-term storage of radioactive waste would remain. Fusion reactors also generate generate high-level wastes with long-term exposure rates that are lower than those of light water reactors [fr

  9. Suprathermal fusion reactions in laser-imploded D-T pellets. Applicability to pellet diagnosis and necessity of nuclear data

    International Nuclear Information System (INIS)

    Tabaru, Y.; Nakao, Y.; Kudo, K.; Nakashima, H.

    1995-01-01

    The suprathermal fusion reaction is examined on the basis of coupled transport/hydrodynamic calculation. We also calculate the energy spectrum of neutrons bursting from DT pellet. Because of suprathermal fusion and rapid pellet expansion, these neutrons contain fast components whose maximum energy reachs about 40 MeV. The pellet ρR diagnosis by the detection of suprathermal fusion neutrons is discussed. (author)

  10. Calculations of Excitation Functions of Some Structural Fusion Materials for ( n, t) Reactions up to 50 MeV Energy

    Science.gov (United States)

    Tel, E.; Durgu, C.; Aktı, N. N.; Okuducu, Ş.

    2010-06-01

    Fusion serves an inexhaustible energy for humankind. Although there have been significant research and development studies on the inertial and magnetic fusion reactor technology, there is still a long way to go to penetrate commercial fusion reactors to the energy market. Tritium self-sufficiency must be maintained for a commercial power plant. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. So, the working out the systematics of ( n, t) reaction cross sections is of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at different energies. In this study, ( n, t) reactions for some structural fusion materials such as 27Al, 51V, 52Cr, 55Mn, and 56Fe have been investigated. The new calculations on the excitation functions of 27Al( n, t)25Mg, 51V( n, t)49Ti, 52Cr( n, t)50V, 55Mn( n, t)53Cr and 56Fe( n, t)54Mn reactions have been carried out up to 50 MeV incident neutron energy. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve the new evaluated the geometry dependent hybrid model, hybrid model and the cascade exciton model. Equilibrium effects are calculated according to the Weisskopf-Ewing model. Also in the present work, we have calculated ( n, t) reaction cross-sections by using new evaluated semi-empirical formulas developed by Tel et al. at 14-15 MeV energy. The calculated results are discussed and compared with the experimental data taken from the literature.

  11. Analysis and characterization of heavy residues produced in 129Xe + natSn reactions between 8 and 25 AMeV

    International Nuclear Information System (INIS)

    Moisan, J.

    2008-06-01

    Studies with the INDRA multidetector of the 129 Xe + nat Sn reactions showed the unexpected existence of heavy fragments with a charge as large as Z=70. The charges of Xe and Sn are 54 and 50 respectively. Reactions between nuclei with a charge product greater than 2700 are dominated by deep inelastic collisions. For Xe + Sn the product is exactly 2700. After these observations, 129 Xe + nat Sn reactions at 8, 12, 15, 20 and 25 AMeV have been done. It will then be possible to clarify if the heavy residues are formed by an incomplete fusion, massive transfers occurring in deep inelastic collisions or a very asymmetric fission of a compound system. This work will present experimental results obtained by the analysis of these experiments. We will show that heavy residues are formed with a production cross-section of 10 -2 mb. Angular distributions show that the residues can be produced by an incomplete fusion of the projectile and the target. The study of the products in coincidence with the residues shows that a compound system was formed, followed by a fission producing the residue and a lighter fragment. The comparison with a phenomenological model, HIPSE, confirms that the model is valid at these energies

  12. The IGNITEX fusion project

    International Nuclear Information System (INIS)

    Carrera, R.

    1987-01-01

    The author discusses the recently proposed fusion ignition experiment, IGNITEX. He emphasizes the basic ideas of this concept rather than the specific details of the physics and engineering aspects of the experiment. This concept is a good example of the importance of maintaining an adequate balance between the basic scientific progress in fusion physics and the new technologies that are becoming available in order to make fusion work. The objective of the IGNITEX project is to produce and control ignited plasmas for scientific study in the simplest and least expensive way possible. Being able to study this not-yet-produced regime of plasma operation is essential to fusion research. Two years after the fission nuclear reaction was discovered, a non-self-sustained fission reaction was produced in a laboratory, and in one more year a self-sustained reaction was achieved at the University of Chicago. However, after almost forty years of fusion research, a self-sustained fusion reaction has yet not been produced in a laboratory experiment. This fact indicates the greater difficulty of the fusion experiment. Because of the difficulty involved in the production of a self-sustained fusion reaction, it is necessary to propose such an experiment with maximum ignition margins, maximum simplicity, and minimum financial risk

  13. Inertial confinement fusion reaction chamber and power conversion system study. Final report

    International Nuclear Information System (INIS)

    Maya, I.; Schultz, K.R.; Bourque, R.F.

    1985-10-01

    This report summarizes the results of the second year of a two-year study on the design and evaluation of the Cascade concept as a commercial inertial confinement fusion (ICF) reactor. We developed a reactor design based on the Cascade reaction chamber concept that would be competitive in terms of both capital and operating costs, safe and environmentally acceptable in terms of hazard to the public, occupational exposure and radioactive waste production, and highly efficient. The Cascade reaction chamber is a double-cone-shaped rotating drum. The granulated solid blanket materials inside the rotating chamber are held against the walls by centrifugal force. The fusion energy is captured in a blanket of solid carbon, BeO, and LiAlO 2 granules. These granules are circulated to the primary side of a ceramic heat exchanger. Primary-side granule temperatures range from 1285 K at the LiAlO 2 granule heat exchanger outlet to 1600 K at the carbon granule heat exchanger inlet. The secondary side consists of a closed-cycle gas turbine power conversion system with helium working fluid, operating at 1300 K peak outlet temperature and achieving a thermal power conversion efficiency of 55%. The net plant efficiency is 49%. The reference design is a plant producing 1500 MW of D-T fusion power and delivering 815 MW of electrical power for sale to the utility grid. 88 refs., 44 figs., 47 tabs

  14. Comparative studies for different proximity potentials applied to sub-barrier fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, G.L. [Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); Beihang University, Key Laboratory of Micro-Nano Measurement-Manipulation and Physics (Ministry of Education), Beijing (China); Qu, W.W. [Medical College of Soochow University, School of Radiation Medicine and Protection, Soochow (China); Guo, M.F.; Qian, J.Q. [Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); Zhang, H.Q. [China Institute of Atomic Energy, Beijing (China); Wolski, R. [Henryk Niewodniczanski Institute of Nuclear Physics PAS, Cracow (Poland)

    2016-02-15

    Coulomb barrier heights calculated by using 14 different versions of proximity potentials are studied and applied for experimental data of fusion in terms of a recently proposed energy scaling approach. The results show that the descriptions of proximity potentials 77 and 88 for the barrier heights seem to be closest to the values required by the systematics. On the basis of proximity potential 77, the parameterized formulas of the barrier height and radius are obtained. These formulas can calculate the barrier positions and barrier heights reasonably well within the error, respectively. Thus it provides a simple and direct way to calculate the barrier positions and barrier heights for heavy-ion fusion reactions. (orig.)

  15. A survey of selected neutron-activation reactions with short-lived products of importance to fusion reactor technology

    International Nuclear Information System (INIS)

    Ward, R.C.; Gomes, I.C.; Smith, D.L.

    1994-11-01

    The status of the cross sections for production of short-lived radioactivities in the intense high-energy neutron fields associated with D-T fusion reactors is investigated. The main concerns relative to these very radioactive isotopes are with radiation damage to sensitive components such as superconducting magnets, the decay-heat problem and the safety of personnel during operation of the facility. The present report surveys the status of nuclear data required to assess these problems. The study is limited to a few high-priority nuclear reactions which appear to be of critical concern in this context. Other reactions of lesser concern are listed but are not treated in the present work. Among the factors that were considered in defining the relevant reactions and setting priorities are: quantities of the elemental materials in a fusion reactor, isotopic abundances within elemental categories, the decay properties of the induced radioactive byproducts, the reaction cross sections, and the nature of the decay radiations. Attention has been focused on radioactive species with half lives in the range from about 1 second to 15 minutes. Available cross-section and reaction-product decay information from the literature has been compiled and included in the report. Uncertainties have been estimated by examining several sets of experimental as well as evaluated data. Comments on the general status of data for various high-priority reactions are offered. On the basis of this investigation, it has been found that the nuclear data are in reasonably good shape for some of the most important reactions but are unacceptable for others. Based on this investigation, the reactions which should be given the greatest attention are: 16 O(n,p) 16 N, 55 Mn(n,p) 55 Cr, 57 Fe(n,p) 57 Mn, 186 W(n,2n) 185m W, and 207 Pb(n,n') 207m Pb. However, the development of fusion power would benefit from an across-the-board refinement in these nuclear data so that a more accurate quantitative

  16. Low-energy d+d fusion reactions via the Trojan Horse Method

    Energy Technology Data Exchange (ETDEWEB)

    Tumino, A., E-mail: tumino@lns.infn.it [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Universita degli Studi di Enna ' Kore' , Enna (Italy); Spitaleri, C. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Mukhamedzhanov, A.M. [Cyclotron Institute Texas A and M University, College Station, TX (United States); Typel, S. [Excellence Cluster Universe, Technische Universitaet Muenchen, Garching (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH - Theorie, Darmstadt (Germany); Aliotta, M. [School of Physics and Astronomy, University of Edinburgh, Edinburgh, Scotland (United Kingdom); Scottish Universities Physics Alliance (United Kingdom); Burjan, V. [Nuclear Physics Institute of ASCR, Rez near Prague (Czech Republic); Gimenez del Santo, M. [Departamento de Fisica Nuclear, Universitade de Sao Paulo, Sao Paulo (Brazil); Kiss, G.G. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); ATOMKI, Debrecen (Hungary); Kroha, V.; Hons, Z. [Nuclear Physics Institute of ASCR, Rez near Prague (Czech Republic); La Cognata, M.; Lamia, L. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Mrazek, J. [Nuclear Physics Institute of ASCR, Rez near Prague (Czech Republic); Pizzone, R.G. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Piskor, S. [Nuclear Physics Institute of ASCR, Rez (Czech Republic); Rapisarda, G.G.; Romano, S.; Sergi, M.L.; Sparta, R. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy)

    2011-06-06

    The bare nucleus S(E) factors for the {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He reactions have been measured for the first time via the Trojan Horse Method off the proton in {sup 3}He from 1.5 MeV down to 2 keV. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre-Main-Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from available direct data with new S(0) values of 57.4{+-}1.8 MeVb for {sup 3}H+p and 60.1{+-}1.9 MeVb for {sup 3}He+n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors.

  17. Low-energy d+d fusion reactions via the Trojan Horse Method

    International Nuclear Information System (INIS)

    Tumino, A.; Spitaleri, C.; Mukhamedzhanov, A.M.; Typel, S.; Aliotta, M.; Burjan, V.; Gimenez del Santo, M.; Kiss, G.G.; Kroha, V.; Hons, Z.; La Cognata, M.; Lamia, L.; Mrazek, J.; Pizzone, R.G.; Piskor, S.; Rapisarda, G.G.; Romano, S.; Sergi, M.L.; Sparta, R.

    2011-01-01

    The bare nucleus S(E) factors for the 2 H(d,p) 3 H and 2 H(d,n) 3 He reactions have been measured for the first time via the Trojan Horse Method off the proton in 3 He from 1.5 MeV down to 2 keV. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre-Main-Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from available direct data with new S(0) values of 57.4±1.8 MeVb for 3 H+p and 60.1±1.9 MeVb for 3 He+n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors.

  18. Influence of hexadecapole deformations of the nuclear shape of subbarrier fusion reactions

    International Nuclear Information System (INIS)

    Fernandez Niello, J.

    1989-01-01

    A systematic study of the contribution of hexadecapole deformations to the enhancement of subbarrier fusion cross reactions is carried out. The analysis is based on calculations that cover the full range of values of hexadecapole deformations found in actual nuclear systems. The interplay of this shape degree of freedom with the presence of prolate quadrupole deformations is also contemplated. (Author) [es

  19. Synthesis of single-crystalline hollow β-FeOOH nanorods via a controlled incomplete-reaction course

    International Nuclear Information System (INIS)

    Yu Haiyun; Song Xinyu; Yin Zhilei; Fan Weiliu; Tan Xuejie; Fan Chunhua; Sun Sixiu

    2007-01-01

    The single-crystalline β-FeOOH hollow nanorods with a diameter ranging from 20∼30 nm and length in the range of 70-110 nm have been successfully synthesized through a two-step route in the solution. The phase transformation and the morphologies of the hollow β-FeOOH nanorods were investigated with X-ray powdered diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electric diffraction (SAED), high-resolution transmission electron microscopy (HRTEM), infrared spectrum (IR) and thermo-gravimetric analysis (TGA). These studies indicate that the first step is an incomplete-reaction course. Furthermore, The formation mechanism of the hollow nanorods has been discussed. It is found that the mixed system including chitosan and n-propanol is essential for the final formation of the hollow β-FeOOH nanorods

  20. Experimental investigation of the confinement of d(3He,p)α and d(d,p)t fusion reaction products in JET

    DEFF Research Database (Denmark)

    Bonheure, Georges; Hult, M.; Gonzalez de Orduna, R.

    2012-01-01

    In ITER, magnetic fusion will explore the burning plasma regime. Because such burning plasma is sustained by its own fusion reactions, alpha particles need to be confined (Hazeltine 2010 Fusion Eng. Des. 7–9 85). New experiments using d(3He,p)α and d(d,p)t fusion reaction products were performed...... in JET. Fusion product loss was measured from MHD-quiescent plasmas with a charged particle activation probe installed at a position opposite to the magnetic field ion gradient drift (see figure 1)—1.77 m above mid-plane—in the ceiling of JET tokamak. This new kind of escaping ion detector (Bonheure et...... al 2008 Fusion Sci. Technol. 53 806) provides for absolutely calibrated measurements. Both the mechanism and the magnitude of the loss are dealt with by this research. Careful analysis shows measured loss is in quantitative agreement with predictions from the classical orbit loss model. However...

  1. Neutron-induced reactions relevant for Inertial-Cofinement Fusion Experiments

    Science.gov (United States)

    Boswell, Melissa; Devlin, Mathew; Fotiadis, Nikolaos; Merrill, Frank; Nelson, Ronald; Tonchev, Anton

    2014-09-01

    The typical ignition experiment at the National Ignition Facility ablatively implodes a plastic capsule filled with DT fuel, generating a high flux of 14-MeV neutrons from the d(t,n) α reaction. There is some spread in the energy of these primary 14-MeV neutrons, which is mainly attributable to Doppler shifting from the relative thermal motion of the burning DT fuel. Neutrons created during this reaction have 5--10% chance of scattering before escaping the fuel assembly, losing some fraction of their energy in the scattering process. Neutrons emerging with an energy greater than the reaction energy are generated by a two-step process where neutrons first transfer momentum to a deuteron or tritium ion, these enhanced energy ions then fuse in flight to produce higher energy neutrons; some of these neutrons have energies in excess of 30 MeV. Measuring the fluencies of both the low- and high-energy neutrons is a powerful mechanism for studying the properties of the fuel assembly, and the various parameters important to inertial confinement fusion. We have developed a number of tools to measure the spectral characteristics of the NIF neutron spectrum. Most of these methods rely on exploiting the energy dependence of (n, γ), (n,2n), (n,3n) and (n,p) reactions on a variety o.

  2. Fusion barrier distributions from capture and quasi-elastic excitation functions measured in reaction 36S, 48Ca, 64Ni+238U

    International Nuclear Information System (INIS)

    Kozulin, E. M.

    2009-01-01

    The subbarrier fusion enhancement in reactions with heavy ions were explained by taking into account coupling between relative motion and intrinsic degrees of freedom of interacting nuclei. The coupling of reaction channels manifests itself in the potential barrier between interacting nuclei giving rise to a distribution of fusion barrier instead of single barrier.Capture and quasi-elastic scattering excitation functions at backward angles were measured for 3 6S , 4 8C a, 6 4N i+2 38U reactions systems at energies close and below the Coulomb barrier (i.e. when the influence of the shell effects on the fusion and characteristics of the decay of the composite system is considerable). Representations of the barrier distributions were extracted from both capture and quasi-elastic data. The experimental representations of barrier distributions were compared with coupled-channel calculations using CCFULL code. The major part of these experiments has been performed at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Dubna); at the TANDEM-ALPI accelerator of the LNL (INFN, Legnaro, Italy) and at the Accelerator Laboratory of University of Jyvaeskylae (JYFL, Finland) using a time-of-flight spectrometer of fission fragments CORSET (CORrelation SET-up.) The extraction of the masses and Total Kinetic Energy (TKE) of the binary reaction products is based upon the analysis of the two-body velocity In the case of the fusion-fission and quasi-fission processes, the observed peculiarities of mass and energy distributions of the fragments, the ratio between the fusion-fission and quasi-fission cross sections are determined deformations of interaction nuclei and angular momentum carried in the di-nuclear system and the shell structure of the formed fragments. In this work, the high-precision capture and quasi-elastic scattering excitation function data are presented.The influence of projectile and target excitations and nucleon transfer on fusion barrier

  3. Thermonuclear fusion

    International Nuclear Information System (INIS)

    Weisse, J.

    2000-01-01

    This document takes stock of the two ways of thermonuclear fusion research explored today: magnetic confinement fusion and inertial confinement fusion. The basic physical principles are recalled first: fundamental nuclear reactions, high temperatures, elementary properties of plasmas, ignition criterion, magnetic confinement (charged particle in a uniform magnetic field, confinement and Tokamak principle, heating of magnetized plasmas (ohmic, neutral particles, high frequency waves, other heating means), results obtained so far (scale laws and extrapolation of performances, tritium experiments, ITER project), inertial fusion (hot spot ignition, instabilities, results (Centurion-Halite program, laser experiments). The second part presents the fusion reactor and its associated technologies: principle (tritium production, heat source, neutron protection, tritium generation, materials), magnetic fusion (superconducting magnets, divertor (role, principle, realization), inertial fusion (energy vector, laser adaptation, particle beams, reaction chamber, stresses, chamber concepts (dry and wet walls, liquid walls), targets (fabrication, injection and pointing)). The third chapter concerns the socio-economic aspects of thermonuclear fusion: safety (normal operation and accidents, wastes), costs (costs structure and elementary comparison, ecological impact and external costs). (J.S.)

  4. Muon-catalyzed fusion: A new direction in fusion research

    International Nuclear Information System (INIS)

    Jones, S.E.

    1986-01-01

    In four years of intensive research, muon-catalyzed fusion has been raised from the level of a scientific curiosity to a potential means of achieving clean fusion energy. This novel approach to fusion is based on the fact that a sub-atomic particle known as a ''muon'' can induce numerous energy-releasing fusion reactions without the need for high temperatures or plasmas. Thus, the muon serves as a catalyst to facilitate production for fusion energy. The success of the research effort stems from the recent discovery of resonances in the reaction cycle which make the muon-induced fusion process extremely efficient. Prior estimates were pessimistic in that only one fusion per muon was expected. In that case energy balance would be impossible since energy must be invested to generate the muons. However, recent work has gone approximately half-way to energy balance and further improvements are being worked on. There has been little time to assess the full implications of these discoveries. However, various ways to use muon-catalyzed fusion for electrical power production are now being explored

  5. Muon-catalyzed fusion: a new direction in fusion research

    International Nuclear Information System (INIS)

    Jones, S.E.

    1986-01-01

    In four years of intensive research, muon-catalyzed fusion has been raised from the level of a scientific curiosity to a potential means of achieving clean fusion energy. This novel approach to fusion is based on the fact that a sub-atomic particle known as a ''muon'' can induce numerous energy-releasing fusion reactions without the need for high temperatures or plasmas. Thus, the muon serves as a catalyst to facilitate production for fusion energy. The success of the research effort stems from the recent discovery of resonances in the reaction cycle which make the muon-induced fusion process extremely efficient. Prior estimates were pessimistic in that only one fusion per muon was expected. In that case energy balance would be impossible since energy must be invested to generate the muons. However, recent work has gone approximately half-way to energy balance and further improvements are being worked on. There has been little time to assess the full implications of these discoveries. However, various ways to use muon-catalyzed fusion for electrical power production are now being explored

  6. Estimates of fission barrier heights for neutron-deficient Po to Ra nuclei produced in fusion reactions

    Directory of Open Access Journals (Sweden)

    Sagaidak Roman

    2017-01-01

    Full Text Available The cross section data for fission and evaporation residue production in fusion reactions leading to nuclei from Po to Ra have been considered in a systematic way in the framework of the conventional barrier-passing (fusion model coupled with the statistical model. The cross section data obtained in very asymmetric projectile-target combinations can be described within these models rather well with the adjusted model parameters. In particular, one can scale and fix the macroscopic (liquid-drop fission barrier heights (FBHs for nuclei involved in the de-excitation of compound nuclei produced in the reactions. The macroscopic FBHs for nuclei from Po to Ra have been derived in the framework of such analysis and compared with the predictions of various theoretical models.

  7. Complete fusion excitation function for the 16O + natS reaction

    International Nuclear Information System (INIS)

    Wang Sufang; Zheng Jiwen; Liu Guoxing

    1994-01-01

    The complete fusion excitation function for the 16 O + nat S reaction has been measured in the range of 50-75 MeV with a step of 1.0 MeV by using a position sensitive ΔE-E telescope system. The model parameters have been extracted from data analysis. The striking gross structure of the excitation function has been observed. The energies of peaks are at E CM 38,43 and 48 MeV respectively

  8. Cold fusion reaction ignition at cavitation effect on deuterium-containing media

    International Nuclear Information System (INIS)

    Lipson, A.G.; Deryagin, B.V.; Klyuev, V.A.

    1992-01-01

    A possibility to induce 'cold' nuclear fusion reactions in the process of ultrasound cavitation in heavy water is studied. Nonstationary neutron emission is detected under cavitation in D 2 O on titanium vibrator which has the tracks of cavitation erosion (the vibrator ran in D 2 O to 20 hours). Maximum excess over background (12σ) was recorded under cavitation impact on the suspension of LaNi 5 D x dispersed particle in D 2 O

  9. A Novel Multisensor Traffic State Assessment System Based on Incomplete Data

    Directory of Open Access Journals (Sweden)

    Yiliang Zeng

    2014-01-01

    Full Text Available A novel multisensor system with incomplete data is presented for traffic state assessment. The system comprises probe vehicle detection sensors, fixed detection sensors, and traffic state assessment algorithm. First of all, the validity checking of the traffic flow data is taken as preprocessing of this method. And then a new method based on the history data information is proposed to fuse and recover the incomplete data. According to the characteristics of space complementary of data based on the probe vehicle detector and fixed detector, a fusion model of space matching is presented to estimate the mean travel speed of the road. Finally, the traffic flow data include flow, speed and, occupancy rate, which are detected between Beijing Deshengmen bridge and Drum Tower bridge, are fused to assess the traffic state of the road by using the fusion decision model of rough sets and cloud. The accuracy of experiment result can reach more than 98%, and the result is in accordance with the actual road traffic state. This system is effective to assess traffic state, and it is suitable for the urban intelligent transportation system.

  10. Molecular resonances, fusion reactions and surface transparency of interaction between heavy ions

    International Nuclear Information System (INIS)

    Abe, Yasuhisa.

    1980-01-01

    A review of the Band Crossing Model is given, including recent results on the 16 O + 16 O system. Surface Transparency is discussed in the light of the recent development in our understanding of the fusion reaction mechanisms and by calculating the number of open channels available to direct reactions. The existence of the Molecular Resonance Region is suggested in several systems by the fact that Band Crossing Region overlaps with the Transparent Region. A systematic study predicts molecular resonances in the 14 C + 14 C and 12 C + 14 C systems as prominent as those observed in the 16 O + 16 O and 12 C + 16 O systems

  11. CDCC calculations of fusion of 6Li with targets 144Sm and 154Sm: effect of resonance states

    Science.gov (United States)

    Gómez Camacho, A.; Lubian, J.; Zhang, H. Q.; Zhou, Shan-Gui

    2017-12-01

    Continuum Discretized Coupled-Channel (CDCC) model calculations of total, complete and incomplete fusion cross sections for reactions of the weakly bound 6Li with 144,154Sm targets at energies around the Coulomb barrier are presented. In the cluster structure frame of 6Li→α+d, short-range absorption potentials are considered for the interactions between the ground state of the projectile 6Li and α-d fragments with the target. In order to separately calculate complete and incomplete fusion and to reduce double-counting, the corresponding absorption potentials are chosen to be of different range. Couplings to low-lying excited states 2+, 3- of 144Sm and 2+, 4+ of 154Sm are included. So, the effect on total fusion from the excited states of the target is investigated. Similarly, the effect on fusion due to couplings to resonance breakup states of 6Li, namely, l=2, J π =3+,2+,1+ is also calculated. The latter effect is determined by using two approaches, (a) by considering only resonance state couplings and (b) by omitting these states from the full discretized energy space. Among other things, it is found that both resonance and non-resonance continuum breakup couplings produce fusion suppression at all the energies considered. A. Gómez Camacho from CONACYT, México, J. Lubian from CNPq, FAPERJ, Pronex, Brazil. S.G.Z was partly supported by the NSF of China (11120101005, 11275248, 11525524, 11621131001, 11647601, 11711540016), 973 Program of China (2013CB834400) and the Key Research Program of Frontier Sciences of CAS. H.Q.Z. from NSF China (11375266)

  12. Problem of unstable pivots in the incomplete LU-conjugate gradient method

    International Nuclear Information System (INIS)

    Kershaw, D.S.

    1978-01-01

    Incomplete LU and incomplete-Cholesky conjugate gradient methods are becoming widely used in both laser and magnetic fusion research. In my original presentation of these methods, the problem of what to do if a pivot [L/sub ii/U/sub ii/) becomes very small or zero was raised and only partially answered by the suggestion that it be arbitrarily set to some non-zero value. In what follows it will be shown precisely how small the pivot can become before it must be fixed and precisely what value it should be set to in order to minimize the error in LU. Numerical examples will be given to show that not only does this prescription improve incomplete LU-conjugate gradient methods , but exact LU decomposition carried out with this prescription for handling small pivots and followed by a few linear or conjugate gradient iterations can be much faster than the permutations of rows and columns usually employed to circumvent small pivot problems

  13. On the implementation of a chain nuclear reaction of thermonuclear fusion on the basis of the p+11B process

    Science.gov (United States)

    Belyaev, V. S.; Krainov, V. P.; Zagreev, B. V.; Matafonov, A. P.

    2015-07-01

    Various theoretical and experimental schemes for implementing a thermonuclear reactor on the basis of the p+11B reaction are considered. They include beam collisions, fusion in degenerate plasmas, ignition upon plasma acceleration by ponderomotive forces, and the irradiation of a solid-state target from 11B with a proton beam under conditions of a Coulomb explosion of hydrogen microdrops. The possibility of employing ultra-short high-intensity laser pulses to initiate the p+11B reaction under conditions far from thermodynamic equilibrium is discussed. This and some other weakly radioactive thermonuclear reactions are promising owing to their ecological cleanness—there are virtually no neutrons among fusion products. Nuclear reactions that follow the p+11B reaction may generate high-energy protons, sustaining a chain reaction, and this is an advantage of the p+11B option. The approach used also makes it possible to study nuclear reactions under conditions close to those in the early Universe or in the interior of stars.

  14. Neutrons and fusion

    International Nuclear Information System (INIS)

    Maynard, C.W.

    1976-01-01

    The production of energy from fusion reactions does not require neutrons in the fundamental sense that they are required in a fission reactor. Nevertheless, the dominant fusion reaction, that between deuterium and tritium, yields a 14 MeV neutron. To contrast a fusion reactor based on this reaction with the fission case, 3 x 10 20 such neutrons produced per gigawatt of power. This is four times as many neutrons as in an equivalent fission reactor and they carry seven times the energy of the fission neutrons. Thus, they dominate the energy recovery problem and create technological problems comparable to the original plasma confinement problem as far as a practical power producing device is concerned. Further contrasts of the fusion and fission cases are presented to establish the general role of neutrons in fusion devices. Details of the energy deposition processes are discussed and those reactions necessary for producing additional tritium are outlined. The relatively high energy flux with its large intensity will activate almost any materials of which the reactor may be composed. This activation is examined from the point of view of decay heat, radiological safety, and long-term storage. In addition, a discussion of the deleterious effects of neutron interactions on materials is given in some detail; this includes the helium and hydrogen producing reactions and displacement rate of the lattice atoms. The various materials that have been proposed for structural purposes, for breeding, reflecting, and moderating neutrons, and for radiation shielding are reviewed from the nuclear standpoint. The specific reactions of interest are taken up for various materials and finally a report is given on the status and prospects of data for fusion studies

  15. Numerical simulation by a random particle method of Deuterium-Tritium fusion reactions in a plasma*

    Directory of Open Access Journals (Sweden)

    Charles Fréderique

    2013-01-01

    Full Text Available We propose and we justify a Monte-Carlo algorithm which solves a spatially homogeneous kinetic equation of Boltzmann type that models the fusion reaction between a deuterium ion and a tritium ion, and giving an α particle and a neutron. The proposed algorithm is validated with the use of explicit solutions of the kinetic model obtained by replacing the fusion cross-section by a Maxwellian cross section. On propose et on justifie un algorithme de type Monte-Carlo permettant de résoudre un modèle cinétique homogène en espace de type Boltzmann modélisant la réaction de fusion entre un ion deutérium et un ion tritium, et donnant une particule α et un neutron. L’algorithme proposé est par ailleurs validé via des solutions explicites du modèle cinétique obtenues en remplaçant la section efficace de fusion par une section efficace maxwellienne.

  16. Coupled-channel calculation for cross section of fusion and barrier distribution of {}^{16,17,18}O + {}^{16}O reactions

    Science.gov (United States)

    Fereidonnejad, R.; Sadeghi, H.; Ghambari, M.

    2018-03-01

    In this work, the effect of multi-phonon excitation on heavy-ion fusion reactions has been studied and fusion barrier distributions of energy intervals near and below the Coulomb barrier have been studied for 16,17,18O + 16O reactions. The structure and deformation of nuclear projectiles have been studied. Given the adaptation of computations to experimental data, our calculations predict the behavior of reactions in intervals of energy in which experimental measurements are not available. In addition the S-factor for these reactions has been calculated. The results showed that the structure and deformation of a nuclear projectile are important factors. The S-factor, obtained in the coupled-channel calculations for the {}^{16}O + {}^{16}O, {}^{17}O +{}^{16}O and {}^{18}O +{}^{16}O reactions, showed good agreement with the experimental data and had a maximum value at an energy near 5, 4.5 and 4 MeV, respectively.

  17. The cross sections of fusion-evaporation reactions: the most promising route to superheavy elements beyond Z=118

    Directory of Open Access Journals (Sweden)

    Jadambaa Khuyagbaatar

    2017-01-01

    Full Text Available The synthesis of superheavy elements beyond oganesson (Og, which has atomic number Z = 118, is currently one of the main topics in nuclear physics. An absence of sufficient amounts of target material with atomic numbers heavier than californium (Z = 98 forces the use of projectiles heavier than 48Ca (Z = 20, which has been successfully used for the discoveries of elements with Z = 114 - 118 in complete fusion reactions. Experimental cross sections of 48Ca with actinide targets behave very differently to “cold” and “hot” fusion-evaporation reactions, where doubly-magic lead and deformed actinides are used as targets, respectively. The known cross sections of these reactions have been analysed compared to calculated fission barriers. It has been suggested that observed discrepancies between the cross sections of 48Ca-induced and other fusionevaporation reactions originate from the shell structure of the compound nucleus, which lies in the island of the stability. Besides scarcely known data on other reactions involving heavier projectiles, the most promising projectile for the synthesis of the elements beyond Og seems to be 50Ti. However, detailed studies of 50Ti, 54Cr, 58Fe and 64Ni-induced reactions are necessary to be performed in order to fully understand the complexities of superheavy element formation.

  18. The cross sections of fusion-evaporation reactions: the most promising route to superheavy elements beyond Z=118

    Science.gov (United States)

    Jadambaa, Khuyagbaatar

    2017-11-01

    The synthesis of superheavy elements beyond oganesson (Og), which has atomic number Z = 118, is currently one of the main topics in nuclear physics. An absence of sufficient amounts of target material with atomic numbers heavier than californium (Z = 98) forces the use of projectiles heavier than 48Ca (Z = 20), which has been successfully used for the discoveries of elements with Z = 114 - 118 in complete fusion reactions. Experimental cross sections of 48Ca with actinide targets behave very differently to "cold" and "hot" fusion-evaporation reactions, where doubly-magic lead and deformed actinides are used as targets, respectively. The known cross sections of these reactions have been analysed compared to calculated fission barriers. It has been suggested that observed discrepancies between the cross sections of 48Ca-induced and other fusionevaporation reactions originate from the shell structure of the compound nucleus, which lies in the island of the stability. Besides scarcely known data on other reactions involving heavier projectiles, the most promising projectile for the synthesis of the elements beyond Og seems to be 50Ti. However, detailed studies of 50Ti, 54Cr, 58Fe and 64Ni-induced reactions are necessary to be performed in order to fully understand the complexities of superheavy element formation.

  19. Atomic fusion, Gerrard atomic fusion

    International Nuclear Information System (INIS)

    Gerrard, T.H.

    1980-01-01

    In the approach to atomic fusion described here the heat produced in a fusion reaction, which is induced in a chamber by the interaction of laser beams and U.H.F. electromagnetic beams with atom streams, is transferred to a heat exchanger for electricity generation by a coolant flowing through a jacket surrounding the chamber. (U.K.)

  20. Nuclear dynamics in heavy ion induced fusion-fission reactions

    International Nuclear Information System (INIS)

    Kapoor, S.S.

    1992-01-01

    Heavy ion induced fission and fission-like reactions evolve through a complex nuclear dynamics encountered in the medium energy nucleus-nucleus collisions. In the recent years, measurements of the fragment-neutron and fragment-charged particle angular correlations in heavy ion induced fusion-fission reactions, have provided new information on the dynamical times of nuclear deformations of the initial dinuclear complex to the fission saddle point and the scission point. From the studies of fragment angular distributions in heavy ion induced fission it has been possible to infer the relaxation times of the dinuclear complex in the K-degree of freedom and our recent measurements on the entrance channel dependence of fragment anisotropies have provided an experimental signature of the presence of fissions before K-equilibration. This paper reviews recent experimental and theoretical status of the above studies with particular regard to the questions relating to dynamical times, nuclear dissipation and the effect of nuclear dissipation on the K-distributions at the fission saddle in completely equilibrated compound nucleus. (author). 19 refs., 9 figs

  1. Some fusion perspectives

    International Nuclear Information System (INIS)

    McNally, J.R. Jr.

    1977-01-01

    Some of the concepts of nuclear fusion reactions, advanced fusion fuels, environmental impacts, etc., are explored using the following general outline: I. Principles of Fusion (Nuclear Fuels and Reactions, Lawson Condition, n tau vs T, Nuclear Burn Characteristics); II. Magnetic Mirror Possibilities (the Ion Layer and Electron Layer, Exponential Build-up at MeV energies, Lorentz trapping at GeV energies); III. Pellet Fuel Fusion Prospects (Advanced Pellet Fuel Fusion Prospects, Burn Characteristics and Applications, Excitation-heating Prospects for Runaway Ion Temperatures). Inasmuch as the outline is very skeletal, a significant research and development effort may be in order to evaluate these prospects in more detail and hopefully ''harness the H-bomb'' for peaceful applications, the author concludes. 28 references

  2. Influence of the entrance channel in the fusion reaction 318 MeV 74Ge+74Ge

    International Nuclear Information System (INIS)

    Zhu, L.H.; Cinausero, M.; Angelis, G. de; De Poli, M.; Fioretto, E.; Gadea, A.; Napoli, D.R.; Prete, G.; Lucarelli, F.

    1998-01-01

    Entrance channel effects in the fusion of heavy ions have been studied by using the 74 Ge+ 74 Ge reaction at 318 MeV. The population of the yrast superdeformed band in 144 Gd shows an increase when compared with the results obtained in the more asymmetric 48 Ti+ 100 Mo reaction at 215 MeV. The relative yields of the different evaporation residues produced in the 74 Ge+ 74 Ge and in the 48 Ti+ 100 Mo reactions are very similar, with the exception of the 145,144 Gd residual nuclei (3n and 4n decay channels) which are populated with a larger yield in the symmetric reaction. Statistical model calculations reproduce qualitatively such effect if a fission delay is explicitly taken into account. Effects related to fusion barrier fluctuations seem to be important in determining the spin distributions of the compound nucleus. The spectra of the high energy γ-rays emitted in the 74 Ge+ 74 Ge reaction have been measured as a function of the γ-ray multiplicity as well as in coincidence with selected evaporation residues. They are reproduced by standard statistical model calculations with GDR parameters taken from systematics, demonstrating that, in agreement with dynamical model prediction, the emission of γ-rays from the dinucleus formed in the earlier stage of the collision is unimportant. (orig.)

  3. Application of the water gas shift reaction to fusion fuel exhaust streams

    International Nuclear Information System (INIS)

    McKay, A.M.; Cheh, C.H.; Glass, R.W.

    1983-10-01

    In a Fusion Fuel Clean Up (FCU) system, impurities will be removed from the fusion reactor exhaust and neutral beam line streams. Tritium in this impurity stream will be recovered and recycled to the fuel stream. In one flowsheet configuration of the Tritium Systems Test Assembly (TSTA), tritium is recovered from a simulated impurity stream via uranium hot metal beds and recycled to an isotope separation system. This study has shown, however, that the catalyzed water gas shift reaction, by which (H,D,T) 2 O and CO are converted to (H,D,T) 2 and CO 2 is a better method of (H,D,T) 2 O reduction than the hot metal beds. Catalytic reactors were designed, built and tested to provide data for the design of a prototype reactor to replace the hot metal beds in the FCU system. The prototype reactor contains only 10 g of catalyst and is expected to last at least 5 years. The reactor is small (1.3 cm OD x 13 cm long), operates at low temperatures (approximately 490 K) and will convert water to hydrogen, at a CO/H 2 O ratio of 1.5, with an efficiency of greater than 98 percent. Results show that the catalytic reactor is very stable even during upset conditions. Wide ranges of flow and a CO/H 2 O ratio variance from 1.3 upward have little effect on the conversion efficiency. Short term high temperature excursions do not affect the catalyst and lower temperatures will simply decrease the reaction rate resulting in lower conversions. The reactor appears to be unaffected by NO 2 , CO 2 , O 2 and N 2 in the feed stream at concentration levels expected in a fusion reactor exhaust stream

  4. A DIAMANT Wedding For AFRODITE: Probing Structure and Characterizing Reaction Properties Via Charged-Particle-γ Correlations

    International Nuclear Information System (INIS)

    Mullins, S. M.; Murray, S. H. T.; Bark, R. A.; Gueorguieva, E.; Lawrie, J. J.; Lieder, E. O.; Lieder, R. M.; Papka, P.; Nyako, B. M.; Timar, J.; Berek, G.; Gal, J.; Kalinka, G.; Molnar, J.; Krasznahorkay, A.; Zolnai, L.; Juhasz, K.; Lipoglavsek, M.; Ntshangase, S. S.; Scheurer, J. N.

    2008-01-01

    The DIAMANT-AFRODITE combination has been used to investigate incomplete fusions reactions via the 13 C+ 170 Er entrance channel. The intensity of 176 Hf (populated via the α 3n exit channel) is ∼8% of 178 W (populated via 5n evaporation) which is ∼8 times stronger than that expected from complete fusion. Moreover, 2αxn exit channels leading to Yb nuclei are observed with intensities that are ∼30-to-40% of 176 Hf, for which no yield is expected from complete fusion. A comparison of the intensities from the two-α- and one-α-gated data is consistent with fragmentation of the 13 C beam into (α-α-α-n) which suggests that the population of Yb nuclei results from fusion (or ''massive transfer'') of one the break-up α-particles. A campaign of measurements is scheduled for late 2007 with further investigations planned for 2008, including the continuation of the study of superdeformation in 32 S

  5. Measurement and analysis of excitation functions in 16O + 103Rh system in the excitation energy range ≅ 2-4 MeV/A

    International Nuclear Information System (INIS)

    Singh, Devendra P.; Unnati; Sharma, Manoj Kumar; Singh, Pushpendra P.; Singh, B.P.; Prasad, R.; Gupta, Sunita; Rakesh Kumar; Bhardwaj, H.D.

    2006-01-01

    In the present work, excitation functions for seven evaporation residues (ERs) produced via complete fusion and incomplete fusion processes in 16 O + 103 Rh system have been measured in the energy range ≅ 47-85 MeV, using recoil catcher technique followed by off-line gamma-ray spectrometry. Comparison of the experimental data with statistical model based computer code PACE 2 revealed dominance of incomplete fusion in reactions involving alpha-emission channels. To the best of our knowledge these reactions are being reported for the first time

  6. Physics of laser-plasma interaction for shock ignition of fusion reactions

    International Nuclear Information System (INIS)

    Tikhonchuk, V T; Colaïtis, A; Vallet, A; Llor Aisa, E; Duchateau, G; Nicolaï, Ph; Ribeyre, X

    2016-01-01

    The shock ignition scheme is an alternative approach, which aims to achieve ignition of fusion reactions in two subsequent steps: first, the target is compressed at a low implosion velocity and second, a strong converging shock is launched during the stagnation phase and ignites the hot spot. In this paper we describe the major elements of this scheme and recent achievements concerning the laser-plasma interaction, the crucial role of hot electrons in the shock generation, the shock amplification in the imploding shell and the ignition conditions. (paper)

  7. Origin of a maximum of the astrophysical S factor in heavy-ion fusion reactions at deep subbarrier energies

    Science.gov (United States)

    Hagino, K.; Balantekin, A. B.; Lwin, N. W.; Thein, Ei Shwe Zin

    2018-03-01

    The hindrance phenomenon of heavy-ion fusion cross sections at deep subbarrier energies often accompanies a maximum of an astrophysical S factor at a threshold energy for fusion hindrance. We argue that this phenomenon can naturally be explained when the fusion excitation function is fitted with two potentials, with a larger (smaller) logarithmic slope at energies lower (higher) than the threshold energy. This analysis clearly suggests that the astrophysical S factor provides a convenient tool to analyze the deep subbarrier hindrance phenomenon, even though the S factor may have a strong energy dependence for heavy-ion systems unlike that for astrophysical reactions.

  8. Dynamics of the fusion reaction in the dtμ- system

    International Nuclear Information System (INIS)

    Belyaev, V.B.; Revai, J.; Zubarev, A.L.

    1988-08-01

    A dynamical scheme based on the (td,αn) two-channel model is derived for the description of the fusion reaction in the dtμ - system. Special attention is paid to the correct specification of the final states. Several possibilities are pointed out for the systematic improvement of the sudden approximation for the sticking coefficient. It seems to be useful to outline a general formulation of these processes which would allow a clear comparison of existing approaches. The lack of satisfactory agreement between experimental and theoretical values of the sticking coefficient is a further argument in favour of the programme. (R.P.) 10 refs

  9. Dynamical limitations to heavy-ion fusion

    International Nuclear Information System (INIS)

    Back, B.B.

    1983-01-01

    In spite of the many attempts to synthesize superheavy elements in recent years, these efforts have not yet been successful. Recent improved theoretical models of heavy-ion fusion reactions suggest that the formation of super-heavy elements is hindered by the dynamics of the process. Several recent experiments lend support to these theories. The necessity of an excess radial velocity (extra push) over the Coulomb barrier in order to induce fusion is observed experimentally as predicted by the theory. So is a new reaction mechanism, called quasi-fission which tend to exhaust the part of the reaction cross section, which would otherwise lead to fusion. The present study shows that the angular distribution of fragments from quasi-fission processes are very sensitive to the occurrence of this reaction mechanism. A slight modification of one parameter in the theory demanded by the observation of quasi-fission for lighter projectiles via the angular distributions, has the consequence of posing even more-stringent limitations on heavy-ion-fusion reactions. This reduces even further the possibility for synthesizing and identifying superheavy elements in heavy-ion-fusion reactions

  10. Fusion reactor wastes

    International Nuclear Information System (INIS)

    Young, J.R.

    1976-01-01

    The fusion reactor currently is being developed as a clean source of electricity with an essentially infinite source of fuel. These reactors are visualized as using a fusion reaction to generate large quantities of high temperature energy which can be used as process heat or for the generation of electricity. The energy would be created primarily as the kinetic energy of neutrons or other reaction products. Neutron energy could be converted to high-temperature heat by moderation and capture of the neutrons. The energy of other reaction products could be converted to high-temperature heat by capture, or directly to electricity by direct conversion electrostatic equipment. An analysis to determine the wastes released as a result of operation of fusion power plants is presented

  11. Cross-sections and average angular momenta in fusion reactions near the coulomb barrier

    International Nuclear Information System (INIS)

    Dasgupta, M.

    1992-01-01

    In recent years there has been an increasing interest in the study of heavy ion collisions near the Coulomb barrier. This has been triggered mainly by the observations of enhancements by factors of about one to two order of magnitude in sub-Coulomb barrier fusion (SBF) cross-sections between medium mass nuclei, as compared to predictions based on one-dimensional barrier penetration model (l-d BPM). Though, a considerable amount of work both theoretical and experimental has been done in this field, a complete understanding of the SBF phenomenon has not yet been achieved. The relation between fusion excitation function and angular momentum (l) distribution in SBF reactions is a topic of current interest. It is believed that l-distributions provide a more stringent test of SBF models that the excitation functions alone. Simultaneous measurement of l-distribution (or its moments) and fusion excitation function is expected to lead to a better understanding of the relationship between these two qualities. Such information has been obtained in experiments done at pelletron accelerator facility. In the present talk the measurement of fusion cross-sections and the method of determination of average l from partial evaporation residue cross-section has been elaborated. An analysis of the experimental data on the basis of some of the SBF models has been discussed briefly. (author). 13 refs

  12. Towards fusion power

    International Nuclear Information System (INIS)

    Venkataraman, G.

    1975-01-01

    An attempt has been made to present general but broad review of the recent developments in the field of plasma physics and its application to fusion power. The first chapter describes the fusion reactions and fusion power systems. The second chapter deals in detail with production and behaviour of plasma, screening, oscillations, instability, energy losses, temperature effects, etc. Magnetic confinements, including pinch systems, toroidal systems such as Tokamac and stellarator, minor machine, etc. are discussed in detail in chapter III. Laser produced plasma, laser implosion and problems associated with it and future prospects are explained in chapter IV. Chapter V is devoted entirely to the various aspects of hybrid systems. The last chapter throws light on problems of fusion technology, such as plasma heating, vacuum requirements, radiation damage, choice of materials, blanket problems, hazards of fusion reactions, etc. (K.B.)

  13. Process and apparatus for producing nuclear fusion reactions

    International Nuclear Information System (INIS)

    Maglich, B.C.; Nering, J.E.; Mazarakis, M.G.; Miller, R.A.

    1976-01-01

    A process is submitted for the production of fusion reactions between particles of like polarity. This process consists essentially in delimitating a pumped down space comprising a central axis and a central plane arranged radially, and perpendicular to this central axis, in developing in this space a magnetic field the intensity of which decreases when the radial distance increases from the central axis and of which the intensity increases from the central plane, along this central axis. Particles of the same polarity are produced according to a population distribution in which the density of the particles in the greatest vibrational state exceeds the density of the particles in the greatest vibrational state in a normal distribution. These particles are injected near the centre of the magnetic field, by radial injection towards the inside as from the periphery of the space, in the same plane as the central plane [fr

  14. Resonances and fusion in heavy ion reactions: new models and developments

    International Nuclear Information System (INIS)

    Cindro, N.

    1982-01-01

    Several aspects of the problem of the resonant behaviour of heavy-ion induced reactions are discussed. First, the problem is set in its relation to fundamental nuclear physics and our understanding of nuclear structure. It is suggested that, if the resonant behaviour of heavy-ion reactions is indeed due to the presence of particular configurations in the composite systems, these configurations must have a very specific nature which prevents their mixing with the adjacent states or else other conditons (e.g. low level density) should be met. Further on, the problem of resonant behaviour observed in back-angle elastic scattering and in forward-angle reaction data is discussed. Collisions between heavy ions leading to the composite systems 36 Ar and 40 Ca are used to discuss the apparent lack of correlation between these two sets of data. A way to understand it, based on the fragmentation of broad resonances, is suggested. In the third part the relation between structure in the fusion cross section excitation functions and that in reaction channel cross sections is discussed. Finally, in the fourth part, the orbiting-cluster model of heavy-ion resonances is briefly described and its predictions discussed. Based on this model a list is given of colliding heavy-ion systems where resonances are expected. (author)

  15. Nuclear fusion

    International Nuclear Information System (INIS)

    Al-zaelic, M.M.

    2013-01-01

    Nuclear fusion can be relied on to solve the global energy crisis if the process of limiting the heat produced by the fusion reaction (Plasma) is successful. Currently scientists are progressively working on this aspect whereas there are two methods to limit the heat produced by fusion reaction, the two methods are auto-restriction using laser beam and magnetic restriction through the use of magnetic fields and research is carried out to improve these two methods. It is expected that at the end of this century the nuclear fusion energy will play a vital role in overcoming the global energy crisis and for these reasons, acquiring energy through the use of nuclear fusion reactors is one of the most urge nt demands of all mankind at this time. The conclusion given is that the source of fuel for energy production is readily available and inexpensive ( hydrogen atoms) and whole process is free of risks and hazards, especially to general health and the environment . Nuclear fusion importance lies in the fact that energy produced by the process is estimated to be about four to five times the energy produced by nuclear fission. (author)

  16. Can 250+ fusions per muon be achieved?

    International Nuclear Information System (INIS)

    Jones, S.E.

    1987-01-01

    Nuclear fusion of hydrogen isotopes can be induced by negative muons (μ) in reactions such as: μ - + d + t → α + n + μ - . This reaction is analagous to the nuclear fusion reaction achieved in stars in which hydrogen isotopes (such as deuterium, d, and tritium, t) at very high temperatures first penetrate the Coulomb repulsive barrier and then fuse together to produce an alpha particle (α) and a neutron (n), releasing energy. The muon in general reappears after inducing fusion so that the reaction can be repeated many (N) times. Thus, the muon may serve as an effective catalyst for nuclear fusion. Muon-catalozed fusion is unique in that it proceeds rapidly in deuterium-tritium mixtures at relatively cold temperatures, e.g., room temperature. The need for plasma temperatures to initiate fusion is overcome by the presence of the muon

  17. MHD deceleration of fusion reaction products

    International Nuclear Information System (INIS)

    Chow, S.; Bohachevsky, I.O.

    1979-04-01

    The feasibility of magnetohydrodynamic (MHD) deceleration of fuel pellet debris ions exiting from an inertial confinement fusion (ICF) reactor cavity is investigated using one-dimensional flow equations. For engineering reasons, induction-type devices are emphasized; their performance characteristics are similar to those of electrode-type decelerators. Results of the analysis presented in this report indicate that MHD decelerators can be designed within conventional magnet technology to not only decelerate the high-energy fusion pellet debris ions but also to produce some net electric power in the process

  18. Direct projectile break up its relation to the astrophysically revelant fusion reactions

    International Nuclear Information System (INIS)

    Bertulani, C.A.; Hussein, M.S.

    1990-05-01

    The break-up into two pieces of weakly bound nuclei passing by the Coulomb field of a large Z nucleus can provide useful information on the inverse fusion reactions which are important for the elemental formation in the stars. However, the nuclear interaction complicates considerably the extraction of such information. A study is made of the contributions of the Coulomb and nuclear interaction to the process, showing when the Coulomb break-up prevails and how a reliable separation of multipolarities can be done. (author)

  19. Studies of complex fragment emission in heavy ion reactions. Progress report, January 1, 1993 - September 1, 1995

    International Nuclear Information System (INIS)

    Charity, R.J.; Sobotka, L.G.

    1995-01-01

    This work involves the study of low and intermediate energy heavy-ion nuclear reactions. This work has two foci. First, the authors desired to learn about the properties of both nuclei and nuclear matter under abnormal conditions. Their efforts towards this end run abreast of those for their second focus which is the study of the relevant reaction mechanisms. The two objectives are inexorably linked because their experimental laboratory for studying nuclear properties is a dynamic one. Their task is to answer the questions of how nuclear and nuclear matter properties are reflected in the dynamics of the reactions. The second objective also has great intrinsic value in that they can anticipate improving upon their understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. The program has been: to study the dynamics of fusion reactions, specifically the dynamics of energy, mass, and angular momentum deposition. This work includes reactions near the Coulomb barrier, where fusion dominates the reaction cross section as well as higher energies where incomplete fusion reactions are the primary reactions. This includes the dynamics of fission, still the premier example of collective nuclear motion, as a function of excitation, spin, mass, and mass asymmetry. The authors push these kinds of studies into the intermediate energy domain, and where novel reaction scenarios are predicted. They have studied very central and peripheral collisions between very massive nuclei, and simplified projectile fragmentation reactions utilizing medium to light mass projectiles. The study of central collisions has shown us the importance of collective expansion. The study of peripheral collisions between very heavy nuclei has demonstrated the importance of dynamical production of fragments from the neck region

  20. The fusion-fission process in the reaction {sup 34}S+{sup 186}W near the interaction barrier

    Energy Technology Data Exchange (ETDEWEB)

    Harca, I. M. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, (FLNR JINR) Dubna, Russia and Faculty of Physics, University of Bucharest - P.O. Box MG 11, RO 77125, Bucharest-Magurele (Romania); Dmitriev, S.; Itkis, J.; Kozulin, E. M.; Knyazheva, G.; Loktev, T.; Novikov, K. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, (FLNR JINR) Dubna (Russian Federation); Azaiez, F.; Gottardo, A.; Matea, I.; Verney, D. [IPN, CNRS/IN2P3, Univ. Paris-Sud, 91405 Orsay (France); Chubarian, G. [Cyclotron Institute, Texas A and M University, College Station, TX 77843-3366 (United States); Hanappe, F. [Universite Libre de Bruxelles (ULB), Bruxelles (Belgium); Piot, J.; Schmitt, C. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Trzaska, W. H. [Accelerator Laboratory of University of Jyväskylä (JYFL), Jyväskylä (Finland); Vardaci, E. [Dipartamento di Scienze Fisiche and INFN (INFN-Na), Napoli (Italy)

    2015-02-24

    The reaction {sup 34}S+{sup 186}W at E{sub lab}=160 MeV was investigated with the aim of diving into the features of the fusion-fission process. Gamma rays in coincidence with binary reaction fragments were measured using the high efficiency gamma-ray spectrometer ORGAM at the TANDEM Accelerator facility of I.P.N., Orsay, and the time-of-flight spectrometer for fission fragments (FF) registration CORSET of the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna. The coupling of the ORGAM and CORSET setups offers the unique opportunity of extracting details for characterizing the fusion-fission process and gives information regarding production of neutron-rich heavy nuclei. The FF–γ coincidence method is of better use then the γ – γ coincidence method when dealing with low statistic measurements and also offers the opportunity to precisely correct the Dopler shift for in-flight emitted gamma rays. Evidence of symmetric and asymmetric fission modes were observed in the mass and TKE distributions, occurring due to shell effects in the fragments. Coincident measurements allow for discrimination between the gamma rays by accepting a specific range within the mass distribution of the reaction products. Details regarding the experimental setup, methods of processing the acquisitioned data and preliminary results are presented.

  1. Reduction methodology for reaction cross sections induced by weakly bound nuclei

    International Nuclear Information System (INIS)

    Deshmukh, N.N.; Mukherjee, S.; Appannababu, S.; Guimaraees, V.; Lubian, J.; Gomes, P.R.S.

    2009-01-01

    The interest in nuclear reactions with weakly bound nuclei has increased considerably along the last decade. Several experiments with stable and unstable projectiles have been performed and a variety of theoretical approaches have been developed. In particular, fusion and breakup reactions induced by such projectiles have been the object of several studies. Owing to the weak binding of the projectile, the breakup cross section may be quite large and coupling with the breakup channel can strongly affect the fusion cross section at near barrier energies. This influence stems from two effects, one of a static and the other of a dynamic nature, which are, however, not easy to be disentangled. The static effect results from the more diffuse density of the weakly bound nuclei, as compared with a strongly bound one. The contribution from weakly bound nucleons to the nuclear density extends further out and this gives rise to a lower and thicker potential barrier. There is general understanding that this static effect enhances the fusion cross section at near barrier energies. On the other hand, there is the dynamic effect corresponding to the coupling with the breakup channel. It is well known that the coupling with a finite number of bound channels enhances the sub-barrier fusion cross section. However, the effect of coupling to channels in the continuum (breakup) is controversial. In first place, one should have in mind that there are different fusion processes in collisions of weakly bound projectiles. One of such processes is the complete fusion, which takes place when the whole mass of the projectile fuses with the target. There may be fusion following breakup. In this case, the compound nucleus may contain the whole mass of the projectile (through sequential fusion of the fragments), or some fragment can escape the interaction region. The former corresponds also to complete fusion (sequential complete fusion) while the latter is known as incomplete fusion. So far

  2. Fusion reaction yield in focused discharges with variable energy and plasma fine structure

    International Nuclear Information System (INIS)

    Bortolotti, A.; Brzosko, J.S.; Chiara, P. De; Kilic, H.; Mezzetti, F.; Nardi, V.; Powell, C.; Wang, J.

    1992-01-01

    The same linear correlation between the distribution parameters (ΔT and Max ΔV) of the radial current density J between electrodes and the fusion reaction yield per pulse, Y, in the plasma focus (PF) pinch was quantitatively determined from different PF machines. Contact prints of current-sheath fragments (CSF) ejected from the pinch are obtained from 2.5-MeV-D + ions. CSF's show the same submillimetric fine structure of the pinch. (author) 3 refs., 2 tabs

  3. Fusion breeder: its potential role and prospects

    International Nuclear Information System (INIS)

    Lee, J.D.

    1981-01-01

    The fusion breeder is a concept that utilizes 14 MeV neutrons from D + T → n(14.1 MeV) + α(3.5 MeV) fusion reactions to produce more fuel than the tritium (T) needed to sustain the fusion process. This excess fuel production capacity is used to produce fissile material (Pu-239 or U-233) for subsequent use in fission reactors. We are concentrating on a class of blankets we call fission suppressed. The blanket is the region surrounding the fusion plasma in which fusion neutrons interact to produce fuel and heat. The fission-suppressed blanket uses non-fission reactions (mainly (n,2n) or (n,n't)) to generate excess neutrons for the production of net fuel. This is in contrast to the fast fission class of blankets which use (n,fiss) reactions to generate excess neutrons. Fusion reactors with fast fission blankets are commony known as fusion-fission hybrids because they combine fusion and fission in the same device

  4. Laser induced photonuclear and fusion-reactions

    International Nuclear Information System (INIS)

    LoDato, V.A.

    1977-01-01

    The energy release from the fusion-fission pellets is demonstrated. It is shown that the coupling of the fusion-fission process is extremely efficient provided one can obtain the proper compression heating. The pellet of an outer core of (Li6D-Li6T) with an inner core of U238 is shown to be an efficient and practical fuel and can be ignited by the present generation of lasers to produce thermonuclear burn. The demonstration of the efficiency for photonuclear and photofission pellets is shown. However no suitable gamma ray source exists at present to initiate these processes. (orig.) [de

  5. Studies of complex fragment emission in heavy ion reactions

    International Nuclear Information System (INIS)

    Charity, R.J.; Sobotka, L.G.

    1993-01-01

    The study of intermediate-energy heavy-ion nuclear reactions is reported. This work has two foci: the properties of nuclear matter under abnormal conditions, in this energy domain, predominately low densities and the study of the relevant reaction mechanisms. Nuclear matter properties, such as phase transitions, are reflected in the dynamics of the reactions. The process leads to an understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. The program has the following objectives: to study energy, mass, and angular momentum deposition by studying incomplete fusion reactions; to gain confidence in the understanding of how highly excited systems decompose by studying all emissions from the highly excited systems; to push these kinds of studies into the intermediate energy domain (where intermediate mass fragment emission is not improbable) with excitation function studies; and to learn about the dynamics of the decays using particle-particle correlations. The last effort focuses on simple systems, where definitive statements are possible. These avenues of research share a common theme, large complex fragment production. It is this feature, more than any other, which distinguishes the intermediate energy domain

  6. Reaction and fusion cross sections for 32S on 27Al and 48Ti

    International Nuclear Information System (INIS)

    Porto, F.; Sambataro, S.; Kusterer, K.; Liu Ken Pao; Doukellis, G.; Harney, H.L.

    1981-01-01

    Elastic scattering and evaporation residues have been measured for the system 32 S + 27 Al at Esub(c)sub(.)sub(m)sub(.) = 66.4, 73.2 MeV and 32 S + 48 Ti at Esub(c)sub(.)sub(m)sub(.) = 96.0 MeV. Reaction cross sections have been obtained by use of the optical theorem and are found to be about 60% larger than the fusion cross sections. (orig.)

  7. Muon-catalyzed fusion revisited

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-12-15

    A negative muon can induce nuclear fusion in the reaction of deuteron and triton nuclei giving a helium nucleus, a neutron and an emerging negative muon. The muon forms a tightlybound deuteron-triton-muon molecule and fusion follows in about 10{sup -12}s. Then the muon is free again to induce further reactions. Thus the muon can serve as a catalyst for nuclear fusion, which can proceed without the need for the high temperatures which are needed in the confinement and inertial fusion schemes. At room temperature, up to 80 fusions per muon have recently been observed at the LAMPF machine at Los Alamos, and it is clear that this number can be exceeded. These and other results were presented at a summer Workshop on Muon-Catalyzed Fusion held in Jackson, Wyoming. Approximately fifty scientists attended from Austria, Canada, India, Italy, Japan, South Africa, West Germany, and the United States. The Workshop itself is symbolic of the revival of interest in this subject.

  8. ALKALI FUSION OF ROSETTA ZIRCON

    International Nuclear Information System (INIS)

    DAHER, A.

    2008-01-01

    The decomposition of Rosetta zircon by fusion with different types of alkalis has been investigated. These alkalis include sodium hydroxide, potassium hydroxide and eutectic mixture of both. The influences of the reaction temperature, zircon to alkalis ratio, fusion time and the stirring of the reactant on the fusion reaction have been evaluated. The obtained results favour the decomposition of zircon with the eutectic alkalis mixture by a decomposition efficiency of 96% obtained at 500 0 C after one hour

  9. Nuclear fusion: power for the next century

    International Nuclear Information System (INIS)

    1980-05-01

    The basis of fusion reactions is outlined, with special reference to deuterium and tritium (from lithium, by neutron reaction) as reactants, and the state of research worldwide is indicated. The problems inherent in fusion reactions are discussed, plasma is defined, and the steps to be taken to generate electricity from controlled nuclear fusion are stated. Methods of plasma heating and plasma confinement are considered, leading to a description of the tokamak plasma confinement system. Devices under construction include the JET (Joint European Torus) Undertaking in the UK. Plans and possibilities for fusion reactors are discussed. (U.K.)

  10. Plasma nuclear fusion method

    International Nuclear Information System (INIS)

    Yamazaki, Shunpei; Miyanaga, Shoji; Wakaizumi, Kazuhiro; Takemura, Yasuhiko.

    1990-01-01

    Nuclear fusion reactions are attained by plasma gas phase reactions using magnetic fields and microwaves, and the degree of the reactions is controlled. That is, deuterium (D 2 ) is introduced into a plasma container by utilizing the resonance of microwaves capable of generating plasmas at high density higher by more than 10 - 10 3 times as compared with the high frequency and magnetic fields, and an electric energy is applied to convert gaseous D 2 into plasmas and nuclear fusion is conducted. Further, the deuterium ions in the plasmas are attracted to a surface of a material causing nuclear fusion under a negatively biased electric field from the outside (typically represented by Pd or Ti). Then, deuterium nuclei (d) or deuterium ions collide to the surface of the cathode on the side of palladium to conduct nuclear reaction at the surface or the inside (vicinity) thereof. However, a DC bias is applied as an external bias with the side of the palladium being negative. The cold nuclear fusion was demonstrated by placing a neutron counter in the vicinity of the container and confirming neutrons generated there. (I.S.)

  11. First dedicated in-beam X-ray measurement in heavy-ion fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Berner, C. [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); RIKEN, Research Group for Superheavy Elements (Japan); Henning, W. [Argonne National Laboratory, Physics Division (United States); RIKEN, Research Group for Superheavy Elements (Japan); Muecher, D.; Gernhaeuser, R.; Hellgartner, S.; Maier, L. [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); Morita, K.; Morimoto, K.; Kaji, D.; Wakabayashi, Y.; Baba, H. [RIKEN, Research Group for Superheavy Elements (Japan); Lutter, R. [Ludwig-Maximilians-Universitaet, Muenchen (Germany)

    2016-07-01

    We report on an experiment aiming at in-beam X-ray spectroscopy of heavy and superheavy elements (SHE). The goal is to establish K-X-ray spectroscopy as a sensitive tool to identify SHE produced in fusion reactions. SHE, formed after cold or hot fusion, are usually identified via the alpha-decay products, which have to be connected to well-known elements. However, various theories predict spontaneous fission as the dominant decay mode for the daughter nuclides. Additionally, half-lives of these elements are expected to increase to values impeding the identification of SHE solely by their decay. The in-beam identification of the characteristic X-rays would precisely allow to identify the charge number of the produced SHE. Experiments were performed at the RIKEN Nishina Centre for Accelerator based Science by using the gas-filled magnet separator GARIS for superheavy element detection. A high-purity, low-energy planar germanium LEGe-detector was adapted to the GARIS system at the target place for the first time in order to measure the element-characteristic, prompt X-ray emission.

  12. Barriers to fusion

    International Nuclear Information System (INIS)

    Berriman, A.C.; Butt, R.D.; Dasgupta, M.; Hinde, D.J.; Morton, C.R.; Newton, J.O.

    1999-01-01

    The fusion barrier is formed by the combination of the repulsive Coulomb and attractive nuclear forces. Recent research at the Australian National University has shown that when heavy nuclei collide, instead of a single fusion barrier, there is a set of fusion barriers. These arise due to intrinsic properties of the interacting nuclei such deformation, rotations and vibrations. Thus the range of barrier energies depends on the properties of both nuclei. The transfer of matter between nuclei, forming a neck, can also affect the fusion process. High precision data have been used to determine fusion barrier distributions for many nuclear reactions, leading to new insights into the fusion process

  13. Hyperenhanced Li - Li Chemonuclear Fusion

    International Nuclear Information System (INIS)

    Ikegami, Hidetsugu

    2006-01-01

    A new fusion scheme, the Li - Li chemonuclear fusion is presented, where nuclear fusion reactions are linked to atomic fusion reactions. Lithium ions are implanted on a surface of metallic Li liquid at an energy of nuclear stopping (several keV/amu). The ions collide slowly with liquid Li atoms without electronic excitation and lead to the Li - Li chemonuclear fusion through the formation of united atoms or quasi-C atoms at their turning points. Inside the quasi-atoms twin nuclei are confined within respective sub-pm scale spheres of zero-point oscillation and form themselves into ultradense intermediate nuclear complexes. Their density is million times as large as the solar interior density and close to densities of white dwarfs or white-dwarf progenitors of supernovae. This confinement of nuclear complexes is enormously prolonged towards the pycno-nuclear reactions induced by the zero-point oscillation under the presence of thermodynamic force specified by the Gibbs energy change in the quasi-atom formation in the liquid. Resulted rate enhancement of nuclear fusion by a factor of 10 48 has been anticipated. The enhancement is also argued in connection with the Bose-Einstein condensation

  14. Study of the role of complete fusion in the reaction of /sup 48/Ca and /sup 56/Fe with cerium and terbium. [Cross sections, yield curves, tables

    Energy Technology Data Exchange (ETDEWEB)

    Morrissey, D.J.

    1978-05-01

    /sup 48/Ca and /sup 56/Fe beams from the Super HILAC accelerator were used to irradiate thick metal foils of cerium and terbium. Product gamma ray activities were detected offline and individual products were identified by half-life, gamma ray energy and gamma ray abundances. The production cross sections were iteratively fit to charge and mass dispersions to allow correction for parent decay and calculation of mass yields. From the mass yield curves contributions from quasielastic transfer, deep inelastic transfer and complete fusion reaction mechanisms were interred. Complete fusion was made up on contributions from both evaporation residue and fusion-fission products for the /sup 48/Ca induced reactions. However, only fusion-fission products were detected in the /sup 56/Fe induced reactions. Critical angular momenta for fusion were found to be 82 +- 8 h for /sup 48/Ca + /sup 159/Tb and 34 +- 5 h for /sup 56/Fe + /sup 140/Ce, which can be compared with 53 +- 8 h for /sup 12/C + /sup 197/Au (Natowitz, 1970) and 86 +- 5 h for /sup 40/Ar + /sup 165/Ho (Hanappe, 1973). All of these reactions lead to essentially the same compound nucleus and seem to show the dramatic decline in complete fusion for heavy ions larger than /sup 40/Ar. The prediction of this decline was found to be beyond the model calculations of Bass and the critical distance approach of Glas and Mosel.

  15. Fusion, reaction and break-up cross sections of weakly bound projectiles on 64Zn

    International Nuclear Information System (INIS)

    Gomes, P.R.S.; Padron, I.; Rodriguez, M.D.; Marti, G.V.; Anjos, R.M.; Lubian, J.; Veiga, R.; Liguori Neto, R.; Crema, E.; Added, N.; Chamon, L.C.; Fernandez Niello, J.O.; Capurro, O.A.; Pacheco, A.J.; Testoni, J.E.; Abriola, D.; Arazi, A.; Ramirez, M.; Hussein, M.S.

    2004-01-01

    We present new measurements and a general discussion of the behavior of the fusion, break-up and reaction cross sections of different projectiles on the same target 64 Zn, at near and above barrier energies. The projectiles are the tightly bound 16 O, the stable weakly bound 6 Li, 7 Li and 9 Be and the radioactive very weakly bound 6 He nuclei. We also compare the results with the ones for heavier targets

  16. Roles of multi-step transfer in fusion process induced by heavy-ion reactions

    International Nuclear Information System (INIS)

    Imanishi, B.; Oertzen, W. von.

    1993-06-01

    In nucleus-nucleus collisions of the systems, 12 C+ 13 C and 13 C+ 16 O- 12 C+ 17 O, the effects of the multi-step transfers and inelastic excitations on the fusion cross sections are investigated in the framework of the coupled-reaction-channel (CRC) method. Strong CRC effects of the multi-step processes are observed. Namely, the valence neutron in 13 C or 17 O plays an important role in the enhancement of the fusion. The potential barrier is effectively lowered with the formation of the covalent molecule of the configuration, 12 C+n+ 12 C or 12 C+n+ 16 O. In the analyses of the system 12 C+ 13 C, however, it is still required to introduce core-core optical potential of lower barrier height in the state of the positive total parity. This could be due to the neck formation with the nucleons contained in two core nuclei. (author)

  17. Fusion barrier distributions and fission anisotropies

    International Nuclear Information System (INIS)

    Hinde, D.J.; Morton, C.R.; Dasgupta, M.; Leigh, J.R.; Lestone, J.P.; Lemmon, R.C.; Mein, J.C.; Newton, J.O.; Timmers, H.; Rowley, N.; Kruppa, A.T.

    1995-01-01

    Fusion excitation functions for 16,17 O+ 144 Sm have been measured to high precision. The extracted fusion barrier distributions show a double-peaked structure interpreted in terms of coupling to inelastic collective excitations of the target. The effect of the positive Q-value neutron stripping channel is evident in the reaction with 17 O. Fission and evaporation residue cross-sections and excitation functions have been measured for the reaction of 16 O+ 208 Pb and the fusion barrier distribution and fission anisotropies determined. It is found that the moments of the fusion l-distribution determined from the fusion and fission measurements are in good agreement. ((orig.))

  18. Information fusion via constrained principal component regression for robust quantification with incomplete calibrations

    International Nuclear Information System (INIS)

    Vogt, Frank

    2013-01-01

    Graphical abstract: Analysis Task: Determine the albumin (= protein) concentration in microalgae cells as a function of the cells’ nutrient availability. Left Panel: The predicted albumin concentrations as obtained by conventional principal component regression features low reproducibility and are partially higher than the concentrations of algae in which albumin is contained. Right Panel: Augmenting an incomplete PCR calibration with additional expert information derives reasonable albumin concentrations which now reveal a significant dependency on the algae's nutrient situation. -- Highlights: •Make quantitative analyses of compounds embedded in largely unknown chemical matrices robust. •Improved concentration prediction with originally insufficient calibration models. •Chemometric approach for incorporating expertise from other fields and/or researchers. •Ensure chemical, biological, or medicinal meaningfulness of quantitative analyses. -- Abstract: Incomplete calibrations are encountered in many applications and hamper chemometric data analyses. Such situations arise when target analytes are embedded in a chemically complex matrix from which calibration concentrations cannot be determined with reasonable efforts. In other cases, the samples’ chemical composition may fluctuate in an unpredictable way and thus cannot be comprehensively covered by calibration samples. The reason for calibration model to fail is the regression principle itself which seeks to explain measured data optimally in terms of the (potentially incomplete) calibration model but does not consider chemical meaningfulness. This study presents a novel chemometric approach which is based on experimentally feasible calibrations, i.e. concentration series of the target analytes outside the chemical matrix (‘ex situ calibration’). The inherent lack-of-information is then compensated by incorporating additional knowledge in form of regression constraints. Any outside knowledge can be

  19. Tracking and sensor data fusion methodological framework and selected applications

    CERN Document Server

    Koch, Wolfgang

    2013-01-01

    Sensor Data Fusion is the process of combining incomplete and imperfect pieces of mutually complementary sensor information in such a way that a better understanding of an underlying real-world phenomenon is achieved. Typically, this insight is either unobtainable otherwise or a fusion result exceeds what can be produced from a single sensor output in accuracy, reliability, or cost. This book provides an introduction Sensor Data Fusion, as an information technology as well as a branch of engineering science and informatics. Part I presents a coherent methodological framework, thus providing th

  20. Energy from inertial fusion

    International Nuclear Information System (INIS)

    1995-03-01

    This book contains 22 articles on inertial fusion energy (IFE) research and development written in the framework of an international collaboration of authors under the guidance of an advisory group on inertial fusion energy set up in 1991 to advise the IAEA. It describes the actual scientific, engineering and technological developments in the field of inertial confinement fusion (ICF). It also identifies ways in which international co-operation in ICF could be stimulated. The book is intended for a large audience and provides an introduction to inertial fusion energy and an overview of the various technologies needed for IFE power plants to be developed. It contains chapters on (i) the fundamentals of IFE; (ii) inertial confinement target physics; (iii) IFE power plant design principles (requirements for power plant drivers, solid state laser drivers, gas laser drivers, heavy ion drivers, and light ion drivers, target fabrication and positioning, reaction chamber systems, power generation and conditioning and radiation control, materials management and target materials recovery), (iv) special design issues (radiation damage in structural materials, induced radioactivity, laser driver- reaction chamber interfaces, ion beam driver-reaction chamber interfaces), (v) inertial fusion energy development strategy, (vi) safety and environmental impact, (vii) economics and other figures of merit; (viii) other uses of inertial fusion (both those involving and not involving implosions); and (ix) international activities. Refs, figs and tabs

  1. A D-D/D-T fusion reaction based neutron generator system for liver tumor BNCT

    International Nuclear Information System (INIS)

    Koivunoro, H.; Lou, T.P.; Leung, K. N.; Reijonen, J.

    2003-01-01

    Boron-neutron capture therapy (BNCT) is an experimental radiation treatment modality used for highly malignant tumor treatments. Prior to irradiation with low energetic neutrons, a 10B compound is located selectively in the tumor cells. The effect of the treatment is based on the high LET radiation released in the 10 B(n,α) 7 Li reaction with thermal neutrons. BNCT has been used experimentally for brain tumor and melanoma treatments. Lately applications of other severe tumor type treatments have been introduced. Results have shown that liver tumors can also be treated by BNCT. At Lawrence Berkeley National Laboratory, various compact neutron generators based on D-D or D-T fusion reactions are being developed. The earlier theoretical studies of the D-D or D-T fusion reaction based neutron generators have shown that the optimal moderator and reflector configuration for brain tumor BNCT can be created. In this work, the applicability of 2.5 MeV neutrons for liver tumor BNCT application was studied. The optimal neutron energy for external liver treatments is not known. Neutron beams of different energies (1eV < E < 100 keV) were simulated and the dose distribution in the liver was calculated with the MCNP simulation code. In order to obtain the optimal neutron energy spectrum with the D-D neutrons, various moderator designs were performed using MCNP simulations. In this article the neutron spectrum and the optimized beam shaping assembly for liver tumor treatments is presented

  2. Nuclear science experiments with a bright neutron source from fusion reactions on the OMEGA Laser System

    Science.gov (United States)

    Forrest, C. J.; Knauer, J. P.; Schroeder, W. U.; Glebov, V. Yu.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Sickles, M.; Stoeckl, C.; Szczepanski, J.

    2018-04-01

    Subnanosecond impulses of 1013 to 1014 neutrons, produced in direct-drive laser inertial confinement fusion implosions, have been used to irradiate deuterated targets at the OMEGA Laser System (Boehly et al., 1997). The target compounds include heavy water (D2O) and deuterated benzene (C6D6). Yields and energy spectra of neutrons from D(n,2n)p to study the breakup reaction have been measured at a forward angle of θlab = 3 .5∘ ± 3.5° with a sensitive, high-dynamic-range neutron time-of-flight spectrometer to infer the double-differential breakup cross section d2 σ/dE d Ω for 14-MeV D-T fusion neutrons.

  3. Possibilities of achieving fusion reaction with a 4{pi} focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Barsanti, G; Barsella, B; Camerini, M; Federighi, U; Musumeci, L; Talini, N [CAMEN., Leghorn (Italy)

    1958-07-01

    The 4{pi} focusing by means of an electromagnetic field is analysed. The following points considered: (a) The general solutions of system for equations of motion of a mass m with charge +e valid for arbitrary initial conditions. This is necessary for the consideration of imperfectly focused primary trajectories, of the effect of collisions in the vicinity of the origin and of ions produced in the neutral gas which diffuses into the reaction chamber. (b) Investigation of the primary ion injection system, of the density of the ions in the chamber and of the energy balance as a matter of principle. (c) The experimental apparatus needed for 4{pi} focusing of deuterons and a sketch of a fusion reactor.

  4. Dynamic loadings of sodium-water reactions in LMFBR and fusion power designs

    Energy Technology Data Exchange (ETDEWEB)

    Chan, C. K.

    1977-07-01

    In liquid metal fast breeder reactor and lithium cooled fusion reactor, a sodium loop is being proposed to transfer heat from the primary coolant loop to the steam turbine cycle. Although by careful design and quality assurance programs, the probability for steam generator tube failure can be minimized, failure will still occur. The direct contact of sodium and water would cause a chemical reaction where hydrogen and sodium compounds are produced. This paper presents an evaluation of the potential hazards as a result of such a reaction. An analytical method is developed to investigate the extent of the reaction zone and the propagation of the pressure wave in the sodium system. In the calculation, the chemical reaction is assumed to be instantaneous, governed by the equation 2Na(l)+H/sub 2/O(l)..-->..Na/sub 2/O(l)+H/sub 2/(g)+31.4 K cal/gm. mole. Both the temperature and pressure rise in the reaction zone can be established from the energy balance and the equation of state for the gaseous product. As a consequence of the energy released, the chemical products suddenly expand with a high velocity. The expansion also generates a shock wave in both the water and the sodium systems. Results indicate that the reaction zone can expand in a rate of 1500 ft/sec and a shock wave with initial strength of 2300 atmospheres propagates with a speed of 8000 ft/sec into the sodium system. The propagating characteristics of the shock wave are obtained by solving the basic fluid equations. The shock wave decays rapidly, in the neighborhood of milliseconds, as soon as the reaction zone stops to expand. The decrease in the reaction zone pressure allows more water to react with the sodium and a second pulse is generated.

  5. Dynamic loadings of sodium-water reactions in LMFBR and fusion power designs

    International Nuclear Information System (INIS)

    Chan, C.K.

    1977-01-01

    In liquid metal fast breeder reactor and lithium cooled fusion reactor, a sodium loop is being proposed to transfer heat from the primary coolant loop to the steam turbine cycle. Although by careful design and quality assurance programs, the probability for steam generator tube failure can be minimized, failure will still occur. The direct contact of sodium and water would cause a chemical reaction where hydrogen and sodium compounds are produced. This paper presents an evaluation of the potential hazards as a result of such a reaction. An analytical method is developed to investigate the extent of the reaction zone and the propagation of the pressure wave in the sodium system. In the calculation, the chemical reaction is assumed to be instantaneous, governed by the equation 2Na(l)+H 2 O(l)→Na 2 O(l)+H 2 (g)+31.4 K cal/gm. mole. Both the temperature and pressure rise in the reaction zone can be established from the energy balance and the equation of state for the gaseous product. As a consequence of the energy released, the chemical products suddenly expand with a high velocity. The expansion also generates a shock wave in both the water and the sodium systems. Results indicate that the reaction zone can expand in a rate of 1500 ft/sec and a shock wave with initial strength of 2300 atmospheres propagates with a speed of 8000 ft/sec into the sodium system. The propagating characteristics of the shock wave are obtained by solving the basic fluid equations. The shock wave decays rapidly, in the neighborhood of milliseconds, as soon as the reaction zone stops to expand. The decrease in the reaction zone pressure allows more water to react with the sodium and a second pulse is generated

  6. Fusion reaction cross-sections using the Wong model within Skyrme energy density based semiclassical extended Thomas Fermi approach

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Raj, E-mail: rajkumarfzr@gmail.com [Department of Physics, Panjab University, Chandigarh-160014 (India); School of Physics and Material Science, Thapar University, Patiala-147004 (India); Sharma, Manoj K. [School of Physics and Material Science, Thapar University, Patiala-147004 (India); Gupta, Raj K. [Department of Physics, Panjab University, Chandigarh-160014 (India)

    2011-11-15

    First, the nuclear proximity potential, obtained by using the semiclassical extended Thomas Fermi (ETF) approach in Skyrme energy density formalism (SEDF), is shown to give more realistic barriers in frozen density approximation, as compared to the sudden approximation. Then, taking advantage of the fact that, in ETF method, different Skyrme forces give different barriers (height, position and curvature), we use the l-summed extended-Wong model of Gupta and collaborators (2009) under frozen densities approximation for calculating the cross-sections, where the Skyrme force is chosen with proper barrier characteristics, not-requiring additional 'barrier modification' effects (lowering or narrowing, etc.), for a best fit to data at sub-barrier energies. The method is applied to capture cross-section data from {sup 48}Ca + {sup 238}U, {sup 244}Pu, and {sup 248}Cm reactions and to fusion-evaporation cross-sections from {sup 58}Ni + {sup 58}Ni, {sup 64}Ni + {sup 64}Ni, and {sup 64}Ni + {sup 100}Mo reactions, with effects of deformations and orientations of nuclei included, wherever required. Interestingly, whereas the capture cross-sections in Ca-induced reactions could be fitted to any force, such as SIII, SV and GSkI, by allowing a small change of couple of units in deduced l{sub max}-values at below-barrier energies, the near-barrier data point of {sup 48}Ca + {sup 248}Cm reaction could not be fitted to l{sub max}-values deduced for below-barrier energies, calling for a check of data. On the other hand, the fusion-evaporation cross-sections in Ni-induced reactions at sub-barrier energies required different Skyrme forces, representing 'modifications of the barrier', for the best fit to data at all incident center-of-mass energies E{sub c.m.}'s, displaying a kind of fusion hindrance at sub-barrier energies. This barrier modification effect is taken into care here by using different Skyrme forces for reactions belonging to different regions of

  7. Fusion reactors - types - problems

    International Nuclear Information System (INIS)

    Schmitter, K.H.

    1979-07-01

    A short account is given of the principles of fusion reactions and of the expected advantages of fusion reactors. Descriptions are presented of various Tokamak experimental devices being developed in a number of countries and of some mirror machines. The technical obstacles to be overcome before a fusion reactor could be self-supporting are discussed. (U.K.)

  8. Material for fusion reactor

    International Nuclear Information System (INIS)

    Abhishek, Anuj; Ranjan, Prem

    2011-01-01

    To make nuclear fusion power a reality, the scientists are working restlessly to find the materials which can confine the power generated by the fusion of two atomic nuclei. A little success in this field has been achieved, though there are still miles to go. Fusion reaction is a special kind of reaction which must occur at very high density and temperature to develop extremely large amount of energy, which is very hard to control and confine within using the present techniques. As a whole it requires the physical condition that rarely exists on the earth to carry out in an efficient manner. As per the growing demand and present scenario of the world energy, scientists are working round the clock to make effective fusion reactions to real. In this paper the work presently going on is considered in this regard. The progress of the Joint European Torus 2010, ITER 2005, HiPER and minor works have been studied to make the paper more object oriented. A detailed study of the technological and material requirement has been discussed in the paper and a possible suggestion is provided to make a contribution in the field of building first ever nuclear fusion reactor

  9. Cluster correlation effects in 12C+12C and 14N+10B fusion-evaporation reactions

    Directory of Open Access Journals (Sweden)

    Morelli L.

    2015-01-01

    Full Text Available The decay of highly excited states of 24Mg is studied in fusion evaporation events completely detected in charge in the reactions 12C+12C and 14N+10B at 95 and 80 MeV incident energy respectively. The comparison of light charged particles measured spectra with statistical model predictions suggests that the dominant reaction mechanism is compound nucleus (CN formation and decay. However, in both reactions, a discrepancy with statistical expectations is found for α particles detected in coincidence with Carbon, Oxigen and Neon residues. The comparison between the two reactions shows that this discrepancy is only partly explained by an entrance channel effect. Evidence for cluster correlations in excited 24Mg CN is suggested by the comparison between the measured and calculated branching ratios for the channels involving α particles.

  10. Heavy ion fusion reactions: comparison among different models

    Energy Technology Data Exchange (ETDEWEB)

    Canto, L F; Carlson, B V; Hussein, M S

    1988-03-01

    A comparison among different ion fusion models is presented. In particular, the multistep aspects of the recently proposed Dinucleus Doorway Model are made explicit and the model is confronted with other compound nucleus limitation models. It is suggested that the latter models provide effective one-step descriptions of heavy ion fusion.

  11. Probing the role of Skyrme interactions on the fission dynamics of the {sup 6}Li + {sup 238}U reaction

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ishita; Kumar, Raj; Sharma, Manoj K. [Thapar University, School of Physics and Materials Science, Patiala (India)

    2017-06-15

    The performance of selected five Skyrme forces (out of a set of 240), tested by Dutra et al., is analyzed in view of fusion-fission dynamics. These forces are assumed to perform better for neutron-rich systems, so the choice of the reaction is accordingly made by opting for a neutron-rich target in {sup 6}Li + {sup 238}U reaction. This reaction is diagnosed further in reference to fusion hindrance within the dynamical approach of the cluster-decay model (DCM). In order to reduce the computational time, three Skyrme forces are figured out with the criteria that these forces cover the barrier characteristics of the remaining two forces as well. The fission cross-sections are successfully addressed at low energies for the {sup 6}Li + {sup 238}U reaction. However, at relatively higher energies, the excitation functions show theoretical suppression with respect to experimental data, which may be associated with the possible existence of incomplete fusion (ICF). For ICF, we have considered that the {sup 6}Li broke into {sup 4}He + {sup 2}H, as mentioned in the experimental work. The calculations of ICF are carried out for the {sup 4}He + {sup 238}U reaction with the selected Skyrme forces at E{sub c.m.} = 26.20 and 27.51 MeV. These forces address the data nicely for the compound nucleus (CN) as well as ICF processes. Here, the NRAPR force seems to require lesser barrier modification as compared to the other forces, therefore it can be used as an alternate choice for calculating the interaction potential. Additionally, the prediction of cross-sections at lower energies has been done with DCM using the NRAPR force. The l-dependent % barrier modification of the Skyrme forces undertaken is also worked out in reference to fusion hindrance at below barrier energies. (orig.)

  12. The DD Cold Fusion-Transmutation Connection

    Science.gov (United States)

    Chubb, Talbot A.

    2005-12-01

    LENR theory must explain dd fusion, alpha-addition transmutations, radiationless nuclear reactions, and three-body nuclear particle reactions. Reaction without radiation requires many-body D Bloch+ periodicity in both location and internal structure dependencies. Electron scattering leads to mixed quantum states. The radiationless dd fusion reaction is 2-D Bloch+ -> {}4 He Bloch2+. Overlap between {}4 He Bloch2+ and surface Cs leads to alpha absorption. In the Iwamura et al. studies active deuterium is created by scattering at diffusion barriers.

  13. The influence of transfer reactions on the sub-barrier fusion enhancement in the systems {sup 58.64}Ni +, {sup 92,100}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Rehm, K.E.; Jiang, C.L.; Esbensen, H. [and others

    1995-08-01

    High resolution experiments performed during the past few years demonstrated that the various reaction modes occurring in heavy ion collisions can strongly influence each other. This interrelation of the different reaction modes brings a nuclear structure dependence to the fusion and deep-inelastic channels that were previously described in the framework of pure statistical models. In order to fully understand the interrelation between these reaction channels, a complete set of measurements including elastic and inelastic scattering, few-nucleon transfer and fusion is required. In continuation of our earlier measurements of the fusion cross sections in the system {sup 58,64}Ni + {sup 92,100}Mo we finished the studies of the quasielastic process in these systems. The experiments were done in inverse reaction kinematics using the split-pole spectrograph with its hybrid focal-plane detector for particle identification. The experiments with {sup 100}Mo beams were performed previously. First test runs with {sup 92}Mo showed the possible interference with {sup 98}Mo ions which could be eliminated by using the 13{sup +} charge state from the ECR source. The data from these experiments were completely analyzed. The smallest transfer cross sections are observed for the systems {sup 64}Ni + {sup 100}Mo and {sup 58}Ni + {sup 92}Mo, i.e., the most neutron-rich and neutron-deficient systems, respectively. For the other systems, {sup 64}Ni + {sup 92}Mo and {sup 58}Ni + {sup 100}Mo, the transfer cross sections at energies close to the barrier are about of equal magnitude. This observation does not correlate with the deviation of the experimental fusion cross sections from the coupled-channels predictions. While for {sup 58}Ni + {sup 100}Mo discrepancies between the experimental and theoretical fusion cross sections are observed, the system {sup 64}Ni + {sup 92}Mo which shows about the same transfer yields, is quite well described by the coupled-channels calculations.

  14. Controlled Nuclear Fusion.

    Science.gov (United States)

    Glasstone, Samuel

    This publication is one of a series of information booklets for the general public published by The United States Atomic Energy Commission. Among the topics discussed are: Importance of Fusion Energy; Conditions for Nuclear Fusion; Thermonuclear Reactions in Plasmas; Plasma Confinement by Magnetic Fields; Experiments With Plasmas; High-Temperature…

  15. Sensitivity of fusion and quasi-elastic barrier distributions of {sub 16}O+{sub 144}Sm reaction on the coupling radius parameter

    Energy Technology Data Exchange (ETDEWEB)

    Zamrun, Muhammad; Usman, Ida; Variani, Viska Inda [Department of Physics, Haluoleo University, Kendari, Sulawesi Tengagra, 93232 (Indonesia); Kassim, Hasan Abu [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-03-05

    We study the heavy-ion collision at sub-barrier energies of {sub 16}O+{sub 144}Sm system using full order coupled-channels formalism. We especially investigate the sensitivity of fusion and quasi-elastic barrier distributions for this system on the coupling radius parameter. We found that the coupled-channels calculations of the fusion and the quasi-elastic barrier distributions are sensitive to the coupling radius for this reaction in contrast to the fusion and quasi-elastic cross section. Our study indicates that the larger coupling radius, i.e., r{sub coup}=1.20, is required by the experimental quasi-elastic barrier distribution. However, the experimental fusion barrier distribution compulsory the small value, i.e., r{sub coup}=1.06.

  16. On experimental determination of characteristics of nuclear fusion reactions from mu-molecular resonance states

    International Nuclear Information System (INIS)

    Bystritskij, V.M.; Pen'kov, F.M.

    1997-01-01

    Charge-nonsymmetrical deuterium-helium muon complexes (dμHe) are studied. A method is proposed for experimentally determining the rates of nuclear fusion reactions in dμHe molecules in the J=1 and J=0 states (J is the orbital moment of the system) and the partial rates for radiative decay of these complexes in these states. Experiments are supposed to be carried out at meson factories with gaseous and cryogenic targets filled with a mixture of deuterium and helium

  17. rf coupler technology for fusion applications

    International Nuclear Information System (INIS)

    Hoffman, D.J.

    1983-01-01

    Radio frequency (rf) oscillations at critical frequencies have successfully provided a means to convey power to fusion plasmas due to the electrical-magnetic properties of the plasma. While large rf systems to couple power to the plasma have been designed, built, and tested, the main link to the plasma, the coupler, is still in an evolutionary stage of development. Design and fabrication of optimal antennas for fusion applications are complicated by incomplete characterizations of the harsh plasma environment and of coupling mechanisms. A brief description of rf coupler technology required for plasma conditions is presented along with an assessment of the status and goals of coupler development

  18. Nuclear physics for nuclear fusion

    International Nuclear Information System (INIS)

    Li Xingzhong; Liu Bin; Wei Qingming; Ren Xianzhe

    2004-01-01

    The D-T fusion cross-section is calculated using quantum mechanics with the model of square nuclear potential well and Coulomb potential barrier. The agreement between ENDF data and the theoretically calculated results is well in the range of 0.2-280 keV. It shows that the application of Breit-Wigner formula is not suitable for the case of the light nuclei fusion reaction. When this model is applied to the nuclear reaction between the charged particles confined in a lattice, it explains the 'abnormal phenomena'. It implies a prospect of nuclear fusion energy without strong nuclear radiations

  19. Nuclear fusion power

    International Nuclear Information System (INIS)

    Dinghee, D.A.

    1983-01-01

    In this chapter, fusion is compared with other inexhaustible energy sources. Research is currently being conducted both within and outside the USA. The current confinement principles of thermonuclear reactions are reveiwed with the discussion of economics mainly focusing on the magnetic confinement concepts. Environmental, health and safety factors are of great concern to the public and measures are being taken to address them. The magnetic fusion program logic and the inertial fusion program logic are compared

  20. Controlled thermonuclear fusion

    CERN Document Server

    Bobin, Jean Louis

    2014-01-01

    The book is a presentation of the basic principles and main achievements in the field of nuclear fusion. It encompasses both magnetic and inertial confinements plus a few exotic mechanisms for nuclear fusion. The state-of-the-art regarding thermonuclear reactions, hot plasmas, tokamaks, laser-driven compression and future reactors is given.

  1. FENDL/C-1.0. Charged-particle reaction data library for fusion applications Version 1.0 of November 1991. Summary documentation

    International Nuclear Information System (INIS)

    Pashchenko, A.B.

    1995-01-01

    This document describes the FENDL/C-1.0 charged-particle reaction data library which is a sublibrary of FENDL, the evaluated nuclear data library for fusion applications. This file contains evaluated data in ENDF-6 format for the D(d,n), D(d,p), T(d,n), T(t,2n), He-3(d,p) reactions. The processed information, i.e. Maxwellian-averaged reaction rates, and related quantities, calculated from reaction cross-sections, are also included. The data are available from the Nuclear Data Section online via INTERNET by FTP command, or on magnetic tape upon request. (author). 1 tab

  2. Systematics on incomplete fusion dynamics at low energy

    International Nuclear Information System (INIS)

    Rahbar Ali; Afzal Ansari, M.; Kumar, Harish

    2016-01-01

    In the present work, an attempt has been made to study CF and ICF reaction dynamics extensively by using activation and particle-γ coincidence techniques. The excitation functions (EFs) of evaporation residues (ERs) in 20 Ne + 55 Mn, 19 F + 144 Sm, 20 Ne + 159 Tb and 16 O + 156 Gd systems in the energy range ∼ 3-8 MeV/nucleon have been measured by using recoil catcher activation technique followed by γ-ray spectrometry

  3. Dynamical limitations to heavy ion fusion

    International Nuclear Information System (INIS)

    Back, B.B.

    1983-01-01

    Dynamical limitations to heavy ion fusion reaction are considered. The experimental signatures and the importance of a quasi-fission process are examined. The anaular distributions of fission fragments for the 32 S+ 208 Pb and 16 O+ 238 U systems are presented. It is shown that the observations of quasi-fission for even rather ''light'' heavy ions poeess severe limitations on the fusion process. This result may consequently be responsible for the lack of success of the search for super heavy elements in heavy ion fusion reactions

  4. Fusion barriers in heavy ion collisions

    International Nuclear Information System (INIS)

    Zhu Long; Su Jun; Xie Wenjie; Guo Chenchen; Zhang Donghong; Zhang Fengshou

    2014-01-01

    Study of fusion barrier is very important for people to better understand fusion reactions. In this paper the Improved Isospin-dependent Quantum Molecular Dynamics (ImIQMD) model is introduced firstly. Then the shell correction effects, energy dependence, isospin effects and orientation effects of fusion barrier are studied. The fusion barriers for the fusion reactions "4"0Ca + "4"0Ca, "4"8Ca + "2"0"8Pb, "4"8Ca + "2"0"4Pb and "1"6O + "1"5"4Sm are extracted. The negative shell correction energies lower potential barriers of a certain reaction. A complex phenomenon of energy dependence is observed. It is also found that incident energy dependence of the barrier radius and barrier height shows opposite behaviors. The Coulomb potential shows weak energy dependence when distance of two colliding nuclei is lower than the touching distance. The isospin effects of the potential barrier are investigated. The orientation effects of the potential barrier are also discussed for the system "1"6O + "1"5"4Sm. (authors)

  5. Observation of stars produced during cold fusion

    International Nuclear Information System (INIS)

    Matsumoto, T.

    1992-01-01

    It has been indicated tht multiple-neutron nuclei such as quad-neutrons can be emitted during cold fusion. These multiple-neutrons might bombard the nuclei of materials outside a cold fusion cell to cause nuclear reactions. In this paper, observations of nuclear emulsions that were irradiated during a cold fusion experiment with heavy water and palladium foil are described. Various traces, like stars, showing nuclear reactions caused by the multiple-neutrons have been clearly observed

  6. Muon nuclear fusion and low temperature nuclear fusion

    International Nuclear Information System (INIS)

    Nagamine, Kanetada

    1990-01-01

    Low temperature (or normal temperature) nuclear fusion is one of the phenomena causing nuclear fusion without requiring high temperature. In thermal nuclear fusion, the Coulomb barrier is overcome with the help of thermal energy, but in the low temperature nuclear fusion, the Coulomb barrier is neutralized by the introduction of the particles having larger mass than electrons and negative charges, at this time, if two nuclei can approach to the distance of 10 -13 cm in the neutral state, the occurrence of nuclear fusion reaction is expected. As the mass of the particles is heavier, the neutral region is smaller, and nuclear fusion is easy to occur. The particles to meet this purpose are the electrons within substances and muons. The research on muon nuclear fusion became suddenly active in the latter half of 1970s, the cause of which was the discovery of the fact that the formation of muons occurs resonantly rapidly in D-T and D-D systems. Muons are the unstable elementary particles having the life of 2.2 μs, and they can have positive and negative charges. In the muon catalyzed fusion, the muons with negative charge take part. The principle of the muon catalyzed fusion, its present status and future perspective, and the present status of low temperature nuclear fusion are reported. (K.I.)

  7. Stripping of two protons and one alpha particle transfer reactions for 16 O + A Sm and their influence on the fusion cross section

    International Nuclear Information System (INIS)

    Maciel, A.M.M.; Gomes, P.R.S.

    1995-01-01

    Transfer cross section angular distribution data for the stripping of two protons and one alpha particle are studied for the 16 O + A Sm systems (A=144, 148, 150, 152 and 154), at near barrier energies. A semiclassical formalism is used to derive the corresponding transfer form factors. For only one channel the analysis shows evidences that the transfer reaction mechanism at backward angles - corresponding to small distances, may behave as a multi-step process leading to fusion. Simplified coupled channel calculations including transfer channels are performed for the study of the sub-barrier of these systems. The influence of short distance transfer reactions on the fusion is discussed. (author)

  8. Fusion research principles

    CERN Document Server

    Dolan, Thomas James

    2013-01-01

    Fusion Research, Volume I: Principles provides a general description of the methods and problems of fusion research. The book contains three main parts: Principles, Experiments, and Technology. The Principles part describes the conditions necessary for a fusion reaction, as well as the fundamentals of plasma confinement, heating, and diagnostics. The Experiments part details about forty plasma confinement schemes and experiments. The last part explores various engineering problems associated with reactor design, vacuum and magnet systems, materials, plasma purity, fueling, blankets, neutronics

  9. Overview of safety and environmental issues for inertial fusion energy

    International Nuclear Information System (INIS)

    Piet, S.J.; Brereton, S.J.; Tanaka, S.

    1996-01-01

    This paper summarizes safety and environmental issues of Inertial Fusion Energy (IFE): inventories, effluents, maintenance, accident safety, waste management, and recycling. The fusion confinement approach among inertial and magnetic options affects how the fusion reaction is maintained and which materials surround the reaction chamber. The target fill technology has a major impact on the target factory tritium inventory. IFE fusion reaction chambers usually employ some means to protect the first structural wall from fusion pulses. This protective fluid or granular bed also moderates and absorbs most neutrons before they reach the first structural wall. Although the protective fluid activates, most candidate fluids have low activation hazard. Hands-on maintenance seems practical for the driver, target factory, and secondary coolant systems; remote maintenance is likely required for the reaction chamber, primary coolant, and vacuum exhaust cleanup systems. The driver and fuel target facility are well separated from the main reaction chamber

  10. Research in theoretical nuclear physics. Final report, April 1, 1993 - March 31, 1996

    International Nuclear Information System (INIS)

    Udagawa, Takeshi

    1997-08-01

    This report describes the accomplishments in basic research in nuclear physics carried out by the theoretical nuclear physics group in the Department of Physics at the University of Texas at Austin, during the period of April 1, 1993 to March 31, 1996. The work done covers three separate areas, low energy nuclear reactions, intermediate energy physics, and nuclear structure studies. Although the various subjects are spread among different areas, they are all based on two techniques that they have developed in previous years. These techniques are: (a) a powerful method for continuum-random-phase-approximation (CRPA) calculations of the nuclear response; and, (b) the direct reaction approach to complete and incomplete fusion reactions, which enables them to describe on a single footing all the different types of nuclear reactions, i.e., complete fusion, incomplete fusion and direct reactions, in a systematic way based on a single theoretical framework. In this report, the authors first summarize their achievements in these three areas, and then present final remarks

  11. The fusion-fission hybrid

    International Nuclear Information System (INIS)

    Teller, E.

    1985-01-01

    As the history of the development of fusion energy shows, a sustained controlled fusion reaction is much more difficult to produce than rapid uncontrolled release of fusion energy. Currently, the ''magnetic bottle'' technique shows sufficient progress that it might applied for the commercial fuel production of /sup 233/U, suitable for use in fission reactors, by developing a fusion-fission hybrid. Such a device would consist of a fusion chamber core surrounded by a region containing cladded uranium pellets cooled by helium, with lithium salts also present to produce tritium to refuel the fusion process. Successful development of this hybrid might be possible within 10 y, and would provide both experience and funds for further development of controlled fusion energy

  12. Cold nuclear fusion. Germany 2012

    Energy Technology Data Exchange (ETDEWEB)

    Petrescu, Florian Ion

    2012-07-01

    Nuclear fusion is the process by which two or more atomic nuclei join together, or ''fuse'', to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to energy which is released. The binding energy of the resulting nucleus is greater than the binding energy of each of the nuclei that fused to produce it. Fusion is the process that powers active stars. Creating the required conditions for fusion on Earth is very difficult, to the point that it has not been accomplished at any scale for protium, the common light isotope of hydrogen that undergoes natural fusion in stars. In nuclear weapons, some of the energy released by an atomic bomb (fission bomb) is used for compressing and heating a fusion fuel containing heavier isotopes of hydrogen, and also sometimes lithium, to the point of ''ignition''. At this point, the energy released in the fusion reactions is enough to briefly maintain the reaction. Fusion-based nuclear power experiments attempt to create similar conditions using far lesser means, although to date these experiments have failed to maintain conditions needed for ignition long enough for fusion to be a viable commercial power source.

  13. Fusion - 2050 perspective (in Polish)

    CERN Document Server

    Romaniuk, R S

    2013-01-01

    The results of strongly exothermic reaction of thermonuclear fusion between nuclei of deuterium and tritium are: helium nuclei and neutrons, plus considerable kinetic energy of neutrons of over 14 MeV. DT nuclides synthesis reaction is probably not the most favorable one for energy production, but is the most advanced technologically. More efficient would be possibly aneutronic fusion. The EU by its EURATOM agenda prepared a Road Map for research and implementation of Fusion as a commercial method of thermonuclear energy generation in the time horizon of 2050.The milestones on this road are tokomak experiments JET, ITER and DEMO, and neutron experiment IFMIF. There is a hope, that by engagement of the national government, and all research and technical fusion communities, part of this Road Map may be realized in Poland. The infrastructure build for fusion experiments may be also used for material engineering research, chemistry, biomedical, associated with environment protection, power engineering, security, ...

  14. Dynamical Dipole and Equation of State in N/Z Asymmetric Fusion Reactions

    Directory of Open Access Journals (Sweden)

    Giaz Agnese

    2014-03-01

    Full Text Available In heavy ion reactions, in the case of N/Z asymmetry between projectile and target, the process leading to complete fusion is expected to produce pre-equilibrium dipole γ-ray emission. It is generated during the charge equilibration process and it is known as Dynamical Dipole. A new measurement of the dynamical dipole emission was performed by studying 16O + 116Sn at 12 MeV/u. These data, together with those measured at 8.1 MeV/u and 15.6 MeV/u for the same reaction, provide the dependence on the Dynamical Dipole total emission yield with beam energy and they can be compared with theoretical expectations. The experimental results show a weak increase of the Dynamical Dipole total yield with beam energies and are in agreement with the prediction of a theoretical model based on the Boltzmann–Nordheim–Vlasov (BNV approach. The measured trend with beam energy does not confirm the rise and fall behavior previously reported for the same fused compound but with a much higher dipole moment.

  15. Consistent analysis of peripheral reaction channels and fusion for the 16,18O+58Ni systems

    International Nuclear Information System (INIS)

    Alves, J.J.S.; Gomes, P.R.S.; Lubian, J.; Chamon, L.C.; Pereira, D.; Anjos, R.M.; Rossi, E.S.; Silva, C.P.; Alvarez, M.A.G.; Nobre, G.P.A.; Gasques, L.R.

    2005-01-01

    We have measured elastic scattering and peripheral reaction channel cross sections for the 16,18 O+ 58 Ni systems at ELab=46 MeV. The data were analyzed through extensive coupled-channel calculations. It was investigated the consistency of the present analysis with a previous one at sub-barrier energies. Experimental fusion cross sections for these systems are also compared with the corresponding predictions of the coupled-channel calculations

  16. Analytical criterion for shock ignition of fusion reaction in hot spot

    International Nuclear Information System (INIS)

    Ribeyre, X.; Tikhonchuk, V. T.; Breil, J.; Lafon, M.; Vallet, A.; Bel, E. L.

    2013-01-01

    Shock ignition of DT capsules involves two major steps. First, the fuel is assembled by means of a low velocity conventional implosion. At stagnation, the central core has a temperature lower than the one needed for ignition. Then a second, strong spherical converging shock, launched from a high intensity laser spike, arrives to the core. This shock crosses the core, rebounds at the target center and increases the central pressure to the ignition conditions. In this work we consider this latter phase by using the Guderley self-similar solution for converging flows. Our model accounts for the fusion reaction energy deposition, thermal and radiation losses thus describing the basic physics of hot spot ignition. The ignition criterion derived from the analytical model is successfully compared with full scale hydrodynamic simulations. (authors)

  17. Advanced fusion reactor

    International Nuclear Information System (INIS)

    Tomita, Yukihiro

    2003-01-01

    The main subjects on fusion research are now on D-T fueled fusion, mainly due to its high fusion reaction rate. However, many issues are still remained on the wall loading by the 14 MeV neutrons. In the case of D-D fueled fusion, the neutron wall loading is still remained, though the technology related to tritium breeding is not needed. The p- 6 Li and p- 11 B fueled fusions are not estimated to be the next generation candidate until the innovated plasma confinement technologies come in useful to achieve the high performance plasma parameters. The fusion reactor of D- 3 He fuels has merits on the smaller neutron wall loading and tritium handling. However, there are difficulties on achieving the high temperature plasma more than 100 keV. Furthermore the high beta plasma is needed to decrease synchrotron radiation loss. In addition, the efficiency of the direct energy conversion from protons coming out from fusion reaction is one of the key parameters in keeping overall power balance. Therefore, open magnetic filed lines should surround the plasma column. In this paper, we outlined the design of the commercial base reactor (ARTEMIS) of 1 GW electric output power configured by D- 3 He fueled FRC (Field Reversed Configuration). The ARTEMIS needs 64 kg of 3 He per a year. On the other hand, 1 million tons of 3 He is estimated to be in the moon. The 3 He of about 10 23 kg are to exist in gaseous planets such as Jupiter and Saturn. (Y. Tanaka)

  18. Muon catalyzed fusion under compressive conditions

    International Nuclear Information System (INIS)

    Cripps, G.; Goel, B.; Harms, A.A.

    1991-01-01

    The viability of a symbiotic combination of Muon Catalyzed Fusion (μCF) and high density generation processes has been investigated. The muon catalyzed fusion reaction rates are formulated in the temperature and density range found under moderate compressive conditions. Simplified energy gain and power balance calculations indicate that significant energy gain occurs only if standard type deuterium-tritium (dt) fusion is ignited. A computer simulation of the hydrodynamics and fusion kinetics of a spherical deuterium-tritium pellet implosion including muons is performed. Using the muon catalyzed fusion reaction rates formulated and under ideal conditions, the pellet ignites (and thus has a significant energy gain) only if the initial muon concentration is approximately 10 17 cm -3 . The muons need to be delivered to the pellet within a very short-time (≅ 1 ns). The muon pulse required in order to make the high density and temperature muon catalyzed fusion scheme viable is beyond the present technology for muon production. (orig.) [de

  19. Search of fission products in 20Ne-ion beam interaction with 165Ho at 8 MeV/nucleon

    International Nuclear Information System (INIS)

    Singh, D.; Ali, R.; Afzal Ansari, M.; Rashid, M.H.

    2006-01-01

    In the present work, during the study complete fusion (CF) and incomplete fusion (ICF) in 20 Ne-induced reactions, the production cross-sections for several fission products in 20 Ne + 165 Ho system have been measured

  20. Atomic data for fusion

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, H.T.; Kirkpatrick, M.I.; Alvarez, I.; Cisneros, C.; Phaneuf, R.A. (eds.); Barnett, C.F.

    1990-07-01

    This report provides a handbook of recommended cross-section and rate-coefficient data for inelastic collisions between hydrogen, helium and lithium atoms, molecules and ions, and encompasses more than 400 different reactions of primary interest in fusion research. Published experimental and theoretical data have been collected and evaluated, and the recommended data are presented in tabular, graphical and parametrized form. Processes include excitation and spectral line emission, charge exchange, ionization, stripping, dissociation and particle interchange reactions. The range of collision energies is appropriate to applications in fusion-energy research.

  1. Atomic data for fusion

    International Nuclear Information System (INIS)

    Hunter, H.T.; Kirkpatrick, M.I.; Alvarez, I.; Cisneros, C.; Phaneuf, R.A.; Barnett, C.F.

    1990-07-01

    This report provides a handbook of recommended cross-section and rate-coefficient data for inelastic collisions between hydrogen, helium and lithium atoms, molecules and ions, and encompasses more than 400 different reactions of primary interest in fusion research. Published experimental and theoretical data have been collected and evaluated, and the recommended data are presented in tabular, graphical and parametrized form. Processes include excitation and spectral line emission, charge exchange, ionization, stripping, dissociation and particle interchange reactions. The range of collision energies is appropriate to applications in fusion-energy research

  2. Study of breakup and transfer of weakly bound nucleus 6Li to explore the low energy reaction dynamics

    Science.gov (United States)

    Zhang, G. L.; Zhang, G. X.; Hu, S. P.; Zhang, H. Q.; Gomes, P. R. S.; Lubian, J.; Guo, C. L.; Wu, X. G.; Yang, J. C.; Zheng, Y.; Li, C. B.; He, C. Y.; Zhong, J.; Li, G. S.; Yao, Y. J.; Guo, M. F.; Sun, H. B.; Valiente-Dobòn, J. J.; Goasduff, A.; Siciliano, M.; Galtarosa, F.; Francesco, R.; Testov, D.; Mengoni, D.; Bazzacco, D.; John, P. R.; Qu, W. W.; Wang, F.; Zheng, L.; Yu, L.; Chen, Q. M.; Luo, P. W.; Li, H. W.; Wu, Y. H.; Zhou, W. K.; Zhu, B. J.; Li, E. T.; Hao, X.

    2017-11-01

    Investigation of the breakup and transfer effect of weakly bound nuclei on the fusion process has been an interesting research topic in the past several years. However, owing to the low intensities of the presently available radioactive ion beam (RIB), it is difficult to clearly explore the reaction mechanisms of nuclear systems with unstable nuclei. In comparison with RIB, the beam intensities of stable weakly bound nuclei such as 6,7Li and 9Be, which have significant breakup probability, are orders of magnitude higher. Precise fusion measurements have already been performed with those stable weakly bound nuclei, and the effect of breakup of those nuclei on the fusion process has been extensively studied. Those nuclei indicated large production cross sections for particles other than the α + x breakup. The particles are originated from non-capture breakup (NCBU), incomplete fusion (ICF) and transfer processes. However, the conclusion of reaction dynamics was not clear and has the contradiction. In our previous experiments we have performed 6Li+96Zr and 154Sm at HI-13 Tandem accelerator of China Institute of Atomic Energy (CIAE) by using HPGe array. It is shown that there is a small complete fusion (CF) suppression on medium-mass target nucleus 96Zr different from about 35% suppression on heavier target nucleus 154Sm at near-barrier energies. It seems that the CF suppression factor depends on the charge of target nuclei. We also observed one neutron transfer process. However, the experimental data are scarce for medium-mass target nuclei. In order to have a proper understanding of the influence of breakup and transfer of weakly bound projectiles on the fusion process, we performed the 6Li+89Y experiment with incident energies of 22 MeV and 34 MeV on Galileo array in cooperation with Si-ball EUCLIDES at Legnaro National Laboratory (LNL) in Italy. Using particle-particle and particle-γ coincidences, the different reaction mechanisms can be clearly explored.

  3. Concepts for fusion fuel production blankets

    International Nuclear Information System (INIS)

    Gierszewski, P.

    1986-06-01

    The fusion blanket surrounds the burning hydrogen core of the fusion reactor. It is in this blanket that most of the energy released by the DT fusion reaction is converted into useable product, and where tritium fuel is produced to enable further operation of the reactor. Blankets will involve new materials, conditions and processes. Several recent fusion blanket concepts are presented to illustrate the range of ideas

  4. Development of Portable Pulsed Neutron Generators Utilizing a D-T or D-D Fusion Reaction

    International Nuclear Information System (INIS)

    Nishimura, Kazuya; Miake, Yoshinobu; Kato, Michio; Rintsu, Yukou

    2001-01-01

    Prototypes of sealed neutron tubes in a D-T or D-D fusion reaction for logging while drilling (LWD) were developed; then operational tests were performed to check their functional properties. One of the prototypes passed most of the specified conditions for using LWD. Further studies were needed to put a sealed neutron tube into practical use. For applications to other fields, such as an in situ calibration source for neutron detector efficiencies and an in situ calibration source for fusion systems, a sealed neutron tube is needed to have higher-intensity neutron output and a long life. Thus, the performance of the ion source used in the neutron tube is improved to obtain high gas utilization efficiencies or low-pressure operation with high ionization efficiencies. The characteristics of the new ion sources used in the foregoing sealed neutron tube are discussed in terms of preliminary tests. The aforementioned performances are obtained

  5. Breeder control fusion reactor. Topical interview

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, A [Max-Planck-Institut fuer Plasmaphysik, Garching/Muenchen (Germany, F.R.)

    1977-09-01

    The energy sources of the future are extremely controversial. The consumption of fossil fuel shall decrease during the next decades, because exhaustion of the resources, pollution, increase of CO/sub 2/ in the atmosphere and other reasons. But at present the question it not yet settled which alternative energy system should replace the fossil fuel. First of all nuclear energy in the form of fission reactions seems to come into operation to a larger extent. The next step may be the controlled thermonuclear fusion reaction. Furthermore, a comparison between fusion and fission is given which shows that fusion would bring about less risks than the breeders. An advantage of the fusion reactor would be the fact that the fuel cycle is closed. Unfortunately, the physical questions are not as yet satisfactorily clarified so that one cannot be sure whether a fusion reactor can really be built.

  6. Comparison of different Skyrme forces: Fusion barriers and fusion cross sections

    International Nuclear Information System (INIS)

    Puri, R.K.; Gupta, R.K.

    1995-01-01

    Fusion barriers and fusion cross sections are calculated using the Skyrme energy-density formalism. To study the role of different parametrizations of the Skyrme interaction, we use two typical forces, i.e., the original Skyrme force S and the widely used Skyrme force SIII. Our calculations show that, in the reactions considered here, the Skyrme force S gives higher fusion cross sections compared to that of the Skyrme force SIII. The main part of this difference can be associated with the presence of the spin-density contribution in the Skyrme force SIII

  7. Coatings for fusion reactor environments

    International Nuclear Information System (INIS)

    Mattox, D.M.

    1979-01-01

    The internal surfaces of a tokamak fusion reactor control the impurity injection and gas recycling into the fusion plasma. Coating of internal surfaces may provide a desirable and possibly necessary design flexibility for achieving the temperatures, ion densities and containment times necessary for net energy production from fusion reactions to take place. In this paper the reactor environments seen by various componentare reviewed along with possible materials responses. Characteristics of coating-substrate systems, important to fusion applications, are delineated and the present status of coating development for fusion applications is reviewed. Coating development for fusion applications is just beginning and poses a unique and important challenge for materials development

  8. Near barrier fusion, breakup and scattering for the 9Be + 144Sm system

    International Nuclear Information System (INIS)

    Paes, B.; Lubian, J.; Gomes, P.R.S.; Padron, I.; Canto, L.F.

    2009-01-01

    Full text: The investigation of the break-up process of weakly bound nuclei and its influence on the fusion cross section and elastic scattering has been investigated in the last years by different approaches. One of these approaches is the comparison of data of complete fusion (CF) cross sections with predictions from CC calculations which do not include the break-up channel. Different phenomena leading to opposite effects on the fusion cross section may be identified: static effects arising from the longer tail of the nuclear potential and the large size of the weakly bound nuclei, leading to a smaller Coulomb barrier, and dynamical effects, either like the strong coupling between the elastic and continuum states, that takes flux that otherwise would go to fusion or like the coupling of soft resonance states. Very recently a method has been developed by us to disentangle these effects. Another approach to perform this study is the investigation of the presence or absence of the threshold anomaly or the break-up threshold anomaly in the elastic scattering at near barrier energies. The attractive or repulsive characters of the polarization potentials associated with the different reaction processes, may lead to enhancement or suppression of the fusion cross section. In this contribution we analyze, by different approaches, a large set of data for the 9 Be + 144 Sm system, including CF and incomplete fusion, elastic and inelastic scattering. We use a reliable double folding potential in CC calculations which either do not take into account the break-up channel or consider resonances of the 9 Be projectile; we also perform simultaneous fits of elastic and CF cross sections; we derive the break-up cross sections and investigate the energy dependence of the real and imaginary optical potentials corresponding to the fusion and direct processes, separately; and we derive the break-up polarization potential for this system. Then, we show the agreement between these

  9. Advanced fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Yukihiro [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2003-04-01

    The main subjects on fusion research are now on D-T fueled fusion, mainly due to its high fusion reaction rate. However, many issues are still remained on the wall loading by the 14 MeV neutrons. In the case of D-D fueled fusion, the neutron wall loading is still remained, though the technology related to tritium breeding is not needed. The p-{sup 6}Li and p-{sup 11}B fueled fusions are not estimated to be the next generation candidate until the innovated plasma confinement technologies come in useful to achieve the high performance plasma parameters. The fusion reactor of D-{sup 3}He fuels has merits on the smaller neutron wall loading and tritium handling. However, there are difficulties on achieving the high temperature plasma more than 100 keV. Furthermore the high beta plasma is needed to decrease synchrotron radiation loss. In addition, the efficiency of the direct energy conversion from protons coming out from fusion reaction is one of the key parameters in keeping overall power balance. Therefore, open magnetic filed lines should surround the plasma column. In this paper, we outlined the design of the commercial base reactor (ARTEMIS) of 1 GW electric output power configured by D-{sup 3}He fueled FRC (Field Reversed Configuration). The ARTEMIS needs 64 kg of {sup 3}He per a year. On the other hand, 1 million tons of {sup 3}He is estimated to be in the moon. The {sup 3}He of about 10{sup 23} kg are to exist in gaseous planets such as Jupiter and Saturn. (Y. Tanaka)

  10. Nuclear fusion

    International Nuclear Information System (INIS)

    Huber, H.

    1978-01-01

    A comprehensive survey is presented of the present state of knowledge in nuclear fusion research. In the first part, potential thermonuclear reactions, basic energy balances of the plasma (Lawson criterion), and the main criteria to be observed in the selection of appropriate thermonuclear reactions are dealt with. This is followed by a discussion of the problems encountered in plasma physics (plasma confinement and heating, transport processes, plasma impurities, plasma instabilities and plasma diagnostics) and by a consideration of the materials problems involved, such as material of the first wall, fuel inlet and outlet, magnetic field generation, as well as repair work and in-service inspections. Two main methods have been developed to tackle these problems: reactor concepts using the magnetic pinch (stellarator, Tokamak, High-Beta reactors, mirror machines) on the one hand, and the other concept using the inertial confinement (laser fusion reactor). These two approaches and their specific problems as well as past, present and future fusion experiments are treated in detail. The last part of the work is devoted to safety and environmental aspects of the potential thermonuclear aspects of the potential thermonuclear reactor, discussing such problems as fusion-specific hazards, normal operation and potential hazards, reactor incidents, environmental pollution by thermal effluents, radiological pollution, radioactive wastes and their disposal, and siting problems. (orig./GG) [de

  11. Ch. 37, Inertial Fusion Energy Technology

    International Nuclear Information System (INIS)

    Moses, E.

    2010-01-01

    Nuclear fission, nuclear fusion, and renewable energy (including biofuels) are the only energy sources capable of satisfying the Earth's need for power for the next century and beyond without the negative environmental impacts of fossil fuels. Substantially increasing the use of nuclear fission and renewable energy now could help reduce dependency on fossil fuels, but nuclear fusion has the potential of becoming the ultimate base-load energy source. Fusion is an attractive fuel source because it is virtually inexhaustible, widely available, and lacks proliferation concerns. It also has a greatly reduced waste impact, and no danger of runaway reactions or meltdowns. The substantial environmental, commercial, and security benefits of fusion continue to motivate the research needed to make fusion power a reality. Replicating the fusion reactions that power the sun and stars to meet Earth's energy needs has been a long-sought scientific and engineering challenge. In fact, this technological challenge is arguably the most difficult ever undertaken. Even after roughly 60 years of worldwide research, much more remains to be learned. the magnitude of the task has caused some to declare that fusion is 20 years away, and always will be. This glib criticism ignores the enormous progress that has occurred during those decades, progress inboth scientific understanding and essential technologies that has enabled experiments producing significant amounts of fusion energy. For example, more than 15 megawatts of fusion power was produced in a pulse of about half a second. Practical fusion power plants will need to produce higher powers averaged over much longer periods of time. In addition, the most efficient experiments to date have required using about 50% more energy than the resulting fusion reaction generated. That is, there was no net energy gain, which is essential if fusion energy is to be a viable source of electricity. The simplest fusion fuels, the heavy isotopes of

  12. Calculation of high-dimensional fission-fusion potential-energy surfaces in the SHE region

    International Nuclear Information System (INIS)

    Moeller, Peter; Sierk, Arnold J.; Ichikawa, Takatoshi; Iwamoto, Akira

    2004-01-01

    We calculate in a macroscopic-microscopic model fission-fusion potential-energy surfaces relevant to the analysis of heavy-ion reactions employed to form heavy-element evaporation residues. We study these multidimensional potential-energy surfaces both inside and outside the touching point.Inside the point of contact we define the potential on a multi-million-point grid in 5D deformation space where elongation, merging projectile and target spheroidal shapes, neck radius and projectile/target mass asymmetry are independent shape variables. The same deformation space and the corresponding potential-energy surface also describe the shape evolution from the nuclear ground-state to separating fragments in fission, and the fast-fission trajectories in incomplete fusion.For separated nuclei we study the macroscopic-microscopic potential energy, that is the ''collision surface'' between a spheroidally deformed target and a spheroidally deformed projectile as a function of three coordinates which are: the relative location of the projectile center-of-mass with respect to the target center-of-mass and the spheroidal deformations of the target and the projectile. We limit our study to the most favorable relative positions of target and projectile, namely that the symmetry axes of the target and projectile are collinear

  13. Reaction mechanisms for the synthesis of the heaviest elements from heavy ion reactions

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.

    1988-10-01

    This review paper concerns fusion reactions with light heavy-ions, cold fusion, transfer reactions using light heavy-ions or heavy ions. In two appendices, methods for the separation and detection of nuclides in the domain of heaviest elements are described and a comment on the discovery of the element 104 is given. 51 figs., 10 tabs., 335 refs

  14. Fusion as a source of synthetic fuels

    International Nuclear Information System (INIS)

    Powell, J.R.; Fillo, J.A.; Steinberg, M.

    1981-01-01

    In the near-term, coal derived synthetic fuels will be used; but in the long-term, resource depletion and environmental effects will mandate synthetic fuels from inexhaustible sources - fission, fusion, and solar. Of the three sources, fusion appears uniquely suited for the efficient production of hydrogen-based fuels, due to its ability to directly generate very high process temperatures (up to approx. 2000 0 C) for water splitting reactions. Fusion-based water splitting reactions include high temperature electrolysis (HTE) of steam, thermochemical cycles, hybrid electrochemical/thermochemical, and direct thermal decomposition. HTE appears to be the simplest and most efficient process with efficiencies of 50 to 70% (fusion to hydrogen chemical energy), depending on process conditions

  15. Intense fusion neutron sources

    International Nuclear Information System (INIS)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-01-01

    The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 10 15 -10 21 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 10 20 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

  16. Intense fusion neutron sources

    Science.gov (United States)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-04-01

    The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 1020 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

  17. Information Fusion of Conflicting Input Data

    Directory of Open Access Journals (Sweden)

    Uwe Mönks

    2016-10-01

    Full Text Available Sensors, and also actuators or external sources such as databases, serve as data sources in order to realise condition monitoring of industrial applications or the acquisition of characteristic parameters like production speed or reject rate. Modern facilities create such a large amount of complex data that a machine operator is unable to comprehend and process the information contained in the data. Thus, information fusion mechanisms gain increasing importance. Besides the management of large amounts of data, further challenges towards the fusion algorithms arise from epistemic uncertainties (incomplete knowledge in the input signals as well as conflicts between them. These aspects must be considered during information processing to obtain reliable results, which are in accordance with the real world. The analysis of the scientific state of the art shows that current solutions fulfil said requirements at most only partly. This article proposes the multilayered information fusion system MACRO (multilayer attribute-based conflict-reducing observation employing the μBalTLCS (fuzzified balanced two-layer conflict solving fusion algorithm to reduce the impact of conflicts on the fusion result. The performance of the contribution is shown by its evaluation in the scope of a machine condition monitoring application under laboratory conditions. Here, the MACRO system yields the best results compared to state-of-the-art fusion mechanisms. The utilised data is published and freely accessible.

  18. Information Fusion of Conflicting Input Data.

    Science.gov (United States)

    Mönks, Uwe; Dörksen, Helene; Lohweg, Volker; Hübner, Michael

    2016-10-29

    Sensors, and also actuators or external sources such as databases, serve as data sources in order to realise condition monitoring of industrial applications or the acquisition of characteristic parameters like production speed or reject rate. Modern facilities create such a large amount of complex data that a machine operator is unable to comprehend and process the information contained in the data. Thus, information fusion mechanisms gain increasing importance. Besides the management of large amounts of data, further challenges towards the fusion algorithms arise from epistemic uncertainties (incomplete knowledge) in the input signals as well as conflicts between them. These aspects must be considered during information processing to obtain reliable results, which are in accordance with the real world. The analysis of the scientific state of the art shows that current solutions fulfil said requirements at most only partly. This article proposes the multilayered information fusion system MACRO (multilayer attribute-based conflict-reducing observation) employing the μ BalTLCS (fuzzified balanced two-layer conflict solving) fusion algorithm to reduce the impact of conflicts on the fusion result. The performance of the contribution is shown by its evaluation in the scope of a machine condition monitoring application under laboratory conditions. Here, the MACRO system yields the best results compared to state-of-the-art fusion mechanisms. The utilised data is published and freely accessible.

  19. Review for 'Nattoh' model and experimental findings during cold fusion

    International Nuclear Information System (INIS)

    Matsumoto, Takaaki

    1993-01-01

    A review is described for the Nattoh model that provides the framework of the mechanisms of cold fusion. The model classifies the reactions into two categories: fundamental and associated reactions. The former involves the new 'hydrogen-catalyzed' fusion reaction and the chain-reactions of hydrogens. And extremely exciting physics are involved in the latter. Furthermore experimental findings are described. (author)

  20. Study of fusion cross-sections of 16O + 208Pb and 28Si + 208Pb reactions by effective soft-core nucleon-nucleon interaction

    International Nuclear Information System (INIS)

    Ghodsi, O. N.; Mahmodi, M.; Ariai, J.; O. N. Ghodsi)

    2007-01-01

    In this paper, the cross-sections of fusion reactions 16 O + 208 Pb, 28 Si + 208 Pb, 40 C + 40 Ca, 40 Ca + 48 Ca, 58 Ni + 58 Ni, and 16 O + 154 Sm at bombarding energies above and near the fusion barrier have been investigated. The fusion cross-sections have been studied by means of the Monte Carlo method and effective soft-core nucleon-nucleon interaction. One adjustable parameter was used in these calculations. This parameter can change the strength and repulsive parts of soft-core potential values. It has to be adjusted, so that the analytical results are in acceptable agreement with the experimental data. In our calculations, we have taken the range of the nucleon-nucleon soft-core interaction to be constant and equal to that of the M3Y-Raid potential. Results show that the higher values for the diffusion parameter in the Woods-Saxon potential obtained from a careful analysis of 16 O + 208 Pb and 28 Si + 208 Pb reactions are due to the many particle effects on the nucleon-nucleon potential. (author)

  1. Study of fusion cross-sections of 16O + 208Pb and 28Si + 208Pb reactions by effective soft-core nucleon-nucleon interaction

    Directory of Open Access Journals (Sweden)

    Ghodsi Omid N.

    2007-01-01

    Full Text Available In this paper, the cross-sections of fusion reactions 16O + 208Pb, 28Si + 208Pb, 40C + + 40Ca, 40Ca + 48Ca, 58Ni + 58Ni, and 16O + 154Sm at bombarding energies above and near the fusion barrier have been investigated. The fusion cross-sections have been studied by means of the Monte Carlo method and effective soft-core nucleon-nucleon interaction. One adjustable parameter was used in these calculations. This parameter can change the strength and repulsive parts of soft-core potential values. It has to be adjusted, so that the analytical results are in acceptable agreement with the experimental data. In our calculations, we have taken the range of the nucleon-nucleon soft-core interaction to be constant and equal to that of the M3Y-Raid potential. Results show that the higher values for the diffusion parameter in the Woods-Saxon potential obtained from a careful analysis of 16O + 208Pb and 28Si + 208Pb reactions are due to the many particle effects on the nucleon-nucleon potential.

  2. Hydrogen Evolution on Supported Incomplete Cubane-type [Mo3S4](4+) Electrocatalysts

    DEFF Research Database (Denmark)

    Jaramillo, Thomas; Bonde, Jacob Lindner; Zhang, Jingdong

    2008-01-01

    Electrocatalytic properties of biomimetic supported incomplete cubane-type [Mo3S4](4+) clusters are investigated. The activity toward the hydrogen evolution reaction (HER) is evaluated on both a high surface area gas diffusion electrode in a membrane electrode assembly and on highly orientated...

  3. Laser-induced nuclear fusion

    International Nuclear Information System (INIS)

    Jablon, Claude

    1977-01-01

    Research programs on laser-induced thermonuclear fusion in the United States, in Europe and in USSR are reviewed. The principle of the fusion reactions induced is explained, together with the theoretical effects of the following phenomena: power and type of laser beams, shape and size of the solid target, shock waves, and laser-hydrodynamics coupling problems [fr

  4. Elastic scattering, fusion, and breakup of light exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Kolata, J.J. [University of Notre Dame, Physics Department, Notre Dame, IN (United States); Guimaraes, V. [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo, SP (Brazil); Aguilera, E.F. [Instituto Nacional de Investigaciones Nucleares, Departamento de Aceleradores, Mexico, Distrito Federal (Mexico)

    2016-05-15

    The present status of fusion reactions involving light (A< 20) radioactive projectiles at energies around the Coulomb barrier (E<10 MeV per nucleon) is reviewed, emphasizing measurements made within the last decade. Data on elastic scattering (providing total reaction cross section information) and breakup channels for the involved systems, demonstrating the relationship between these and the fusion channel, are also reviewed. Similarities and differences in the behavior of fusion and total reaction cross section data concerning halo nuclei, weakly-bound but less exotic projectiles, and strongly-bound systems are discussed. One difference in the behavior of fusion excitation functions near the Coulomb barrier seems to emerge between neutron-halo and proton-halo systems. The role of charge has been investigated by comparing the fusion excitation functions, properly scaled, for different neutron- and proton-rich systems. Possible physical explanations for the observed differences are also reviewed. (orig.)

  5. Direct conversion of fusion energy

    International Nuclear Information System (INIS)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D- 3 He reaction and the p- 11 B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger βB 2 0 to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high β values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D- 3 He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D 3 He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D 3 He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion or liquid metal MHD conversion (LMMHD). For a D

  6. Direct conversion of fusion energy

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D-{sup 3}He reaction and the p-{sup 11}B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger {beta}B{sup 2}{sub 0} to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high {beta} values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D-{sup 3}He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D{sub 3} He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D{sub 3} He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion

  7. Cold fusion produces more tritium than neutrons

    International Nuclear Information System (INIS)

    Rajagopalan, S.R.

    1989-01-01

    The results of the major cold fusion experiments performed in various laboratories of the world and attempts to explain them are reviewed in brief. Particular reference is made to the experiments carried out in the Bhabha Atomic Research Centre (BARC), Bombay. In BARC experiments, it is found that tritium is the primary product of cold fusion. Author has put forward two hypothetical pictures of D-D fusion. (1) When a metal like Pd or Ti is loaded with D 2 , a crack forms. Propogation of such a crack accelerates deuterons which bombard Pd D 2 /D held by Pd or Ti leading to neutron capture or tritium formation with the release of protons and energy. The released protons might transfer its energy to some other deuteron and a chain reaction is started. This chain reaction terminates when a substantial portion of D in the crack tip is transmuted. This picture explains fusion reaction bursts and the random distribution of reaction sites, but does not explain neutron emission. (2) The deuterons accelerated by a propogating crack may hit a Pd/Ti nucleus instead of a deuterium nucleus and may transmute Pd/Ti. (M.G.B.). 18 refs

  8. Reactions with Weakly Bound Nuclei, at near Barrier Energies, and the Breakup and Transfer Influences on the Fusion and Elastic Scattering

    International Nuclear Information System (INIS)

    Gomes, P. R. S.; Lubian, J.; Mendes-Junior, D. R.; Faria, P. N. de; Linares, R.; Sigaud, L.; Rangel, J.; Ferreira, J. L.; Paes, B.; Cardozo, E. N.; Cortes, M. R.; Canto, L. F.; Ermamatov, M. J.; Otomar, D. R.; Ferioli, E.; Lotti, P.; Hussein, M. S.

    2016-01-01

    We present a brief review of the reaction mechanisms involved in collisions of weakly bound projectiles with tightly bound targets, at near-barrier energies. We discuss systematic behaviors of the data, with emphasis in fusion, breakup, nucleon transfer and elastic scattering. The dependence of the breakup cross section on the charge and mass of the target is discussed, and the influence of the breakup channel on complete fusion is investigated. For this purpose, we compare reduced fusion cross sections with a benchmark universal curve. The behaviors observed in the comparisons are explained in terms of polarization potentials and of nucleon transfer followed by breakup. The influence of the breakup process on elastic scattering is also discussed. Some apparent contradictions between results of different authors are explained and some perspectives of the field are presented. (author)

  9. Fusion enhancement/suppression and irreversibility in reactions induced by weakly bound nuclei

    International Nuclear Information System (INIS)

    Gomes, P.R.S.; Lubian, J.; Canto, L.F.; Chamon, L.C.; Crema, E.; Hussein, M.S.

    2011-01-01

    We show that halo effects enhance fusion cross sections of weakly bound systems, comparing with the situation when there is no-halo. We introduce dimensionless fusion functions and energy variable quantity to investigate systematical trends in the fusion cross sections of weakly bound nuclei at near-barrier energies. We observe very clearly complete fusion suppression at energies above the barrier due to dynamic effects of the breakup on fusion. We explain this suppression in terms of the repulsive polarization potential produced by the breakup. (author)

  10. Effect of deformations on the compactness of odd-Z superheavy nuclei formed in cold and hot fusion reactions

    Science.gov (United States)

    Kaur, Gurjit; Sandhu, Kirandeep; Sharma, Manoj K.

    2018-03-01

    Using the extended fragmentation theory, the compactness of hot and cold fusion reactions is analyzed for odd-Z nuclei ranging Z = 105- 117. The calculations for the present work are carried out at T = 0MeV and ℓ = 0 ħ, as the temperature and angular momentum effects remain silent while addressing the orientation degree of freedom (i.e. compact angle configuration). In the hot fusion, 48Ca (spherical) + actinide (prolate) reaction, the non-equatorial compact (nec) shape is obtained for Z = 113 nucleus. On the other hand, Z > 113 nuclei favor equatorial compact (ec) configuration. The distribution of barrier height (VB) illustrate that the ec-shape is obtained when the magnitude of quadrupole deformation of the nucleus is higher than the hexadecupole deformation. In other words, negligible or small -ve β4-deformations support ec configurations. On the other hand, large (+ve) magnitude of the β4-deformation suggests that the configuration appears for compact angle θc < 90 °, leading to nec structure. Similar deformation effects are observed for Bi-induced reactions, in which not belly-to-belly compact (nbbc) configurations are seen at θc = 42 °. In addition to the effect of β2 and β4-deformations, the exclusive role of octupole deformations (β3) is also analyzed. The β3-deformations do not follow the reflection symmetry as that of β2 and β4, leading to the possible occurrence of compact configuration within 0° to 180° angular range.

  11. Perspectives of fusion power

    International Nuclear Information System (INIS)

    Jensen, V.O.

    1984-01-01

    New and practically inexhaustible sources of energy must be developed for the period when oil, coal and uranium will become scarce and expensive. Nuclear fusion holds great promise as one of these practically inexhaustible energy sources. Based on the deuteriumtritium reaction with tritium obtained from naturally occuring lithium, which is also widely available in Europe, the accessible energy resources in the world are 3.10 12 to 3.10 16 toe; based on the deuterium-deuterium reaction, the deuterium content of the oceans corresponds to 10 20 toe. It is presently envisaged that in order to establish fusion as a large-scale energy source, three major thresholds must be reached: - Scientific feasibility, - Technical feasibility, i.e. the proof that the basic technical problems of the fusion reactor can be solved. - Commercial feasibility, i.e. proof that fusion power reactors can be built on an industrial scale, can be operated reliably and produce usable energy at prices competitive with other energy sources. From the above it is clear that the route to commercial fusion will be long and costly and involve the solution of extremely difficult technical problems. In view of the many steps which have to be taken, it appears unlikely that commercial fusion power will be in general use within the next 50 years and by that time world-wide expenditure on research, development and demonstration may well have exceeded 100 Bio ECU. (author)

  12. Analysis of complete fusion excitation functions for 7Li+152Sm, 197Au and 209Bi reactions at around barrier energies

    International Nuclear Information System (INIS)

    Kharab, Rajesh; Chahal, Rajiv; Kumar, Rajiv

    2017-01-01

    In the present work we have analyzed the fusion excitation function for CF process using the simple Wong’s formula in conjunction with the energy dependent Woods-Saxon potential (EDWSP) in near barrier energy region for 7 Li+ 152 Sm, 197 Au and 209 Bi reactions

  13. Nuclear structure and fusion at the barrier

    International Nuclear Information System (INIS)

    Reisdorf, W.

    1985-01-01

    A comparative study of measured fusion excitation functions in the vicinity of the barrier reveals nuclear structure effects, due in particular to the coupling of the fusion process to direct-reaction channels. (orig.)

  14. Stripping of two protons and one alpha particle transfer reactions for {sup 16} O + {sup A} Sm and their influence on the fusion cross section

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, A.M.M.; Gomes, P.R.S

    1995-12-31

    Transfer cross section angular distribution data for the stripping of two protons and one alpha particle are studied for the {sup 16} O + {sup A} Sm systems (A=144, 148, 150, 152 and 154), at near barrier energies. A semiclassical formalism is used to derive the corresponding transfer form factors. For only one channel the analysis shows evidences that the transfer reaction mechanism at backward angles - corresponding to small distances, may behave as a multi-step process leading to fusion. Simplified coupled channel calculations including transfer channels are performed for the study of the sub-barrier of these systems. The influence of short distance transfer reactions on the fusion is discussed. (author) 16 refs., 5 figs., 5 tabs.

  15. Yrast spectroscopy in {sup 49-51}Ti via fusion-evaporation reaction induced by a radioactive beam

    Energy Technology Data Exchange (ETDEWEB)

    Niikura, M.; Ideguchi, E.; Michimasa, S.; Ota, S.; Shimoura, S.; Wakabayashi, Y. [University of Tokyo, Center for Nuclear Study, Wako, Saitama (Japan); Aoi, N.; Baba, H.; Fukuchi, T.; Ichikawa, Y.; Kubo, T.; Kurokawa, M.; Ohnishi, T.; Suzuki, H.; Yoshida, K. [RIKEN Nishina Center, Wako, Saitama (Japan); Iwasaki, H.; Onishi, T.K.; Suzuki, D. [University of Tokyo, Department of Physics, Tokyo (Japan); Liu, M.; Zheng, Y. [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China)

    2009-12-15

    In-beam {gamma} -ray spectroscopy of high-spin states in {sup 49-51}Ti was performed via the fusion-evaporation reaction using a radioactive beam. By excitation function and {gamma} - {gamma} coincidence analysis, yrast high-spin levels up to I=(21/2{sup -}),(11{sup +}),(17/2{sup -}) in {sup 49-51}Ti were determined. The levels were compared with full-pf -shell model calculation. The level structure indicates the persistency of the N=28 shell gap at yrast states in {sup 49-51}Ti. (orig.)

  16. Application of polarized nuclei to fusion

    International Nuclear Information System (INIS)

    Kulsrud, R.M.

    1987-07-01

    It is shown that the d-t fusion reaction can be modified by polarizing nuclear spins. The ways in which this improves reactor performance are mentioned and the feasibility of the process of spin polarization for magnetic fusion is discussed. 18 refs

  17. Gross resonance-like structure of the complete fusion excitation function for the 16O + 28Si reaction

    International Nuclear Information System (INIS)

    Zheng Jiwen; Zheng Pingzi; Liu Guoxing

    1993-01-01

    The complete fusion excitation function for the 16 O + 28 Si reaction is measured in the incident energy range from 50 to 90 MeV with step of 1.0 MeV using a position sensitive ΔE-E telescope system. The striking gross resonance-like structure is observed when E c.m. c.m. 34.5, 38.5 and 43.0 MeV respectively. The structure vanishes gradually when E c.m. > 46.0 MeV

  18. An electrolytic route to fusion?

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    A patent has been granted by the Swedish Patent Authority for a new process to initiate and control energy generation through fusion reactions of hydrogen. According to the patent-holder, the Swedish company AB Technology Development, the fusion power process could be available for commercial applications within 4-5 years if laboratory and pilot plant tests prove successful. The new process employs a high voltage discharge in heavy water to create conditions under which, according to the patent holder, a high probability of fusion is achieved without the extraordinary high temperatures required in a conventional fusion reactor. (author)

  19. Inertial fusion with hypervelocity impact

    International Nuclear Information System (INIS)

    Olariu, S.

    1998-01-01

    The physics of the compression and ignition processes in inertial fusion is to a certain extent independent of the nature of the incident energy pulse. The present strategy in the field of inertial fusion is to study several alternatives of deposition of the incident energy, and, at the same time, of conducting studies with the aid of available incident laser pulses. In a future reactor based on inertial fusion, the laser beams may be replaced by ion beams, which have a better energy efficiency. The main projects in the field of inertial fusion are the National Ignition Facility (NIF) in USA, Laser Megajoule (LMJ) in France, Gekko XII in Japan and Iskra V in Russia. NIF will be constructed at Lawrence Livermore National Laboratory, in California. LMJ will be constructed near Bordeaux. In the conventional approach to inertial confinement fusion, both the high-density fuel mass and the hot central spot are supposed to be produced by the deposition of the driver energy in the outer layers of the fuel capsule. Alternatively, the driver energy could be used only to produce the radial compression of the fuel capsule to high densities but relatively low temperatures, while the ignition of fusion reactions in the compressed capsule should be effected by a synchronized hypervelocity impact. Using this arrangement, it was supposed that a 54 μm projectile is incident with a velocity of 3 x 10 6 m s -1 upon a large-yield deuterium-tritium target at rest. The collision of the incident projectile and of the large-yield target takes place inside a high-Z cavity. A laser or heavy-ion pulse is converted at the walls of the cavity into X-rays, which compresses the incident projectile and the large-yield target in high-density states. The laser pulse and the movement of the incident projectile are synchronized such that the collision should take place when the densities are the largest. The collision converts the kinetic energy of the incident projectile into thermal energy, the

  20. Fusion, magnetic confinement

    International Nuclear Information System (INIS)

    Berk, H.L.

    1992-01-01

    An overview is presented of the principles of magnetic confinement of plasmas for the purpose of achieving controlled fusion conditions. Sec. 1 discusses the different nuclear fusion reactions which can be exploited in prospective fusion reactors and explains why special technologies need to be developed for the supply of tritium or 3 He, the probable fuels. In Sec. 2 the Lawson condition, a criterion that is a measure of the quality of confinement relative to achieving fusion conditions, is explained. In Sec. 3 fluid equations are used to describe plasma confinement. Specific confinement configurations are considered. In Sec. 4 the orbits of particle sin magneti and electric fields are discussed. In Sec. 5 stability considerations are discussed. It is noted that confinement systems usually need to satisfy stability constraints imposed by ideal magnetohydrodynamic (MHD) theory. The paper culminates with a summary of experimental progress in magnetic confinement. Present experiments in tokamaks have reached the point that the conditions necessary to achieve fusion are being satisfied

  1. Fusion, resonances and scattering in C reaction

    Indian Academy of Sciences (India)

    respectively. In each of these regions, we find some important features in the results ofσfus. ... draws attention in the astrophysical studies [2,7]. Here, Ecm and η .... We outline the concept of selective resonance tunneling for fusion in Ü3. In Ü4 ...

  2. Unichannel description of the fusion reactions

    International Nuclear Information System (INIS)

    Franzin, V.L.M.

    1987-01-01

    Using an effective one channel model which contains channel coupling effects through the presence of an inclusive energy - dependent polarization potential it was studied sub-barrier fusion of the systems A1 Ni+ A2 N1 and 16 O+ A Sm. The consistency of this method is checked by comparing this empirical polarization potential with the one determined from the explicit consideration of a specific channel coupling. (A.C.A.S.) [pt

  3. Studies of complex fragment emission in heavy ion reactions

    International Nuclear Information System (INIS)

    Sobotka, L.G.

    1989-01-01

    The production of large fragments, fragments with mass between light particles and fission fragments, in intermediate and high energy nuclear reactions has fostered the proposal of a number of novel reaction mechanisms. These include liquid-vapor equilibrium and nuclear shattering. Temporarily left in the wake of these exciting proposed mechanisms was the old standard, statistical decay of compound nuclei. To be sure, the standard treatment of compound nucleus decay did not deal with large fragment production. However, this omission was not due to any fundamental deficiency of statistical models, but rather an uncertainty concerning exactly how to splice large fragment emission into statistical models. A large portion of our program deals with this problem. Specifically, by studying the yields of large fragments produced in sufficiently low energy reactions we are attempting to deduce the asymmetry and l-wave dependence of large fragment emission from compound nuclear intermediates. This, however, is only half of the problem. Since the novel mechanisms proposed for large fragment emission were spawned by intermediate and high energy reaction data, we must also realize the relevance of the compound nucleus mechanisms at high energies. It is not unreasonable to suspect that compound nucleus-like objects are formed with less than complete momentum transfer and perhaps less than complete mass transfer. Therefore the study of energy, mass, and angular momentum transfer in incomplete fusion and non-compound reactions. This thread joins the apparently divergent subjects covered in this report

  4. Pulsed fission/fusion hybrid engines

    International Nuclear Information System (INIS)

    Hudson, G.C.

    1979-01-01

    Research into high-thrust, high-specific impulse rocket engines using energy from nuclear reactions which has been conducted at this organization will be discussed. The engines are all conceptual in nature, yet are within the realization of conventional or near-term technology. The engine concepts under study at Foundation, Inc. are designed to obviate or minimize these negative effects of the ORION scheme. By using non-chemical triggers to initiate a non-breakeven fusion reaction at the core of a target composed of both fission and fusion fuel, it should be possible to employ the fusion neutrons thus produced to begin a fission reaction in U-235 or Pu-239. Since the density of the target can be increased by as much as a factor of 250 through compression of the pellet, the amount of fission material necessary to produce a critical mass can be greatly reduced. (This also means that the amount of fission products produced for a giventhrust level is also reduced from the ORION levels.) Coupling this eeffect to the large number of 14 MeV fusion neutrons produced early in the compression process and subsequently to the heating of some additional fusion fuel surrounding the critical mass leads to the very efficient burnup of the target. This insures both high yield from the target as well as low cost per MJ energy released. Finally, the use of such small pellets allows the scale of the energy released to be tailored to a level usable in rocket engines of a few tens of tons thrust level. (orig.) [de

  5. Control of a laser inertial confinement fusion-fission power plant

    Science.gov (United States)

    Moses, Edward I.; Latkowski, Jeffery F.; Kramer, Kevin J.

    2015-10-27

    A laser inertial-confinement fusion-fission energy power plant is described. The fusion-fission hybrid system uses inertial confinement fusion to produce neutrons from a fusion reaction of deuterium and tritium. The fusion neutrons drive a sub-critical blanket of fissile or fertile fuel. A coolant circulated through the fuel extracts heat from the fuel that is used to generate electricity. The inertial confinement fusion reaction can be implemented using central hot spot or fast ignition fusion, and direct or indirect drive. The fusion neutrons result in ultra-deep burn-up of the fuel in the fission blanket, thus enabling the burning of nuclear waste. Fuels include depleted uranium, natural uranium, enriched uranium, spent nuclear fuel, thorium, and weapons grade plutonium. LIFE engines can meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the highly undesirable stockpiles of depleted uranium, spent nuclear fuel and excess weapons materials.

  6. Dynamical fission life-times deduced from gamma-ray emission observed in the fusion-fission reaction : Ne-20 on Bi-209.

    NARCIS (Netherlands)

    vanderPloeg, H; Bacelar, JCS; Buda, A; Dioszegi, [No Value; vantHof, G; vanderWoude, A

    1996-01-01

    The gamma-ray emission spectra between 4 and 20 MeV have been measured for the fusion-fission reactions Ne-20 on Bi-209 --> Np-229* at beam energies 150, 186 and 220 MeV. In addition for the latter experiment the angular dependence of the gamma-ray emission with respect to the spin axis has been

  7. Tritium Aspects of Fueling and Exhaust Pumping in Magnetic Fusion Energy

    Energy Technology Data Exchange (ETDEWEB)

    Baylor, Larry R. [ORNL; Meitner, Steven J. [ORNL

    2017-04-01

    Magnetically confined fusion plasmas generate energy from deuterium-tritium (DT) fusion reactions that produce energetic 3.5 MeV alpha particles and 14 MeV neutrons. Since the DT fusion reaction rate is a strong function of plasma density, an efficient fueling source is needed to maintain high plasma density in such systems. Energetic ions in fusion plasmas are able to escape the confining magnetic fields at a much higher rate than the fusion reactions occur, thus dictating the fueling rate needed. These lost ions become neutralized and need to be pumped away as exhaust gas to be reinjected into the plasma as fuel atoms.The technology to fuel and pump fusion plasmas has to be inherently compatible with the tritium fuel. An ideal holistic solution would couple the pumping and fueling such that the pump exhaust is directly fed back into pellet formation without including impurity gases. This would greatly reduce the processing needs for the exhaust. Concepts to accomplish this are discussed along with the fueling and pumping needs for a DT fusion reactor.

  8. Item calibration in incomplete testing designs

    Directory of Open Access Journals (Sweden)

    Norman D. Verhelst

    2011-01-01

    Full Text Available This study discusses the justifiability of item parameter estimation in incomplete testing designs in item response theory. Marginal maximum likelihood (MML as well as conditional maximum likelihood (CML procedures are considered in three commonly used incomplete designs: random incomplete, multistage testing and targeted testing designs. Mislevy and Sheenan (1989 have shown that in incomplete designs the justifiability of MML can be deduced from Rubin's (1976 general theory on inference in the presence of missing data. Their results are recapitulated and extended for more situations. In this study it is shown that for CML estimation the justification must be established in an alternative way, by considering the neglected part of the complete likelihood. The problems with incomplete designs are not generally recognized in practical situations. This is due to the stochastic nature of the incomplete designs which is not taken into account in standard computer algorithms. For that reason, incorrect uses of standard MML- and CML-algorithms are discussed.

  9. Status of fusion technology

    International Nuclear Information System (INIS)

    Mohan, Ashok

    1978-01-01

    The current status of fusion technology is surveyed. Limited reserves of fossil fuel and dangers of proliferation from nuclear reactors have brought into focus the need to develop an optional energy source. Fusion is being looked upon as an optional energy source which is free from environmental hazards unlike fossil fuels and nuclear reactors. Investments in R and D of fusion energy have increased rapidly in USA, Japan, USSR and European countries. Out of the various fusion fuels known, a mixture of D and T is widely chosen. The main problem in fusion technology is the confinement of plasma for a time sufficient to start the fusion reaction. This can be done magnetically or inertially. The three approaches to magnetic confinement are : (1) tokamak, (2) mirror and (3) pinch. Inertial confinement makes use of lasers or electron beams or ion beams. Both the methods of confinement i.e. magnetic and inertial have problems which are identified and their nature is discussed. (M.G.B.)

  10. The status of cold fusion

    Science.gov (United States)

    Storms, E.

    This report attempts to update the status of the phenomenon of cold fusion. The new field is continuing to grow as a variety of nuclear reactions are discovered to occur in a variety of chemical environments at modest temperatures. However, it must be cautioned that most scientists consider cold fusion as something akin to UFO's, ESP, and numerology.

  11. Cell fusion by ionizing radiation

    International Nuclear Information System (INIS)

    Khair, M.B.

    1993-08-01

    The relevance and importance of cell fusion are illustrated by the notion that current interest in this phenomenon is shared by scientists in quite varied disciplines. The diversity of cellular membrane fusion phenomena could provoke one to think that there must be a multitude of mechanisms that can account for such diversity. But, in general, the mechanism for the fusion reaction itself could be very similar in many, or even all, cases. Cell fusion can be induced by several factors such as virus Sendai, polyethylene glycol, electric current and ionizing radiation. This article provides the reader with short view of recent progress in research on cell fusion and gives some explanations about fusion mechanisms. This study shows for the first time, the results of the cell fusion induced by ionizing radiations that we have obtained in our researches and the work performed by other groups. (author). 44 refs

  12. Material synergism fusion-fission

    International Nuclear Information System (INIS)

    Sankara Rao, K.B.; Raj, B.; Cook, I.; Kohyama, A.; Dudarev, S.

    2007-01-01

    In fission and fusion reactors the common features such as operating temperatures and neutron exposures will have the greatest impact on materials performance and component lifetimes. Developing fast neutron irradiation resisting materials is a common issue for both fission and fusion reactors. The high neutron flux levels in both these systems lead to unique materials problems like void swelling, irradiation creep and helium embitterment. Both fission and fusion rely on ferritic-martensitic steels based on 9%Cr compositions for achieving the highest swelling resistance but their creep strength sharply decreases above ∝ 823K. The use of oxide dispersion strengthened (ODS) alloys is envisaged to increase the operating temperature of blanket systems in the fusion reactors and fuel clad tubes in fast breeder reactors. In view of high operating temperatures, cyclic and steady load conditions and the long service life, properties like creep, low cycle fatigue,fracture toughness and creepfatigue interaction are major considerations in the selection of structural materials and design of components for fission and fusion reactors. Currently, materials selection for fusion systems has to be based upon incomplete experimental database on mechanical properties. The usage of fairly well developed databases, in fission programmes on similar materials, is of great help in the initial design of fusion reactor components. Significant opportunities exist for sharing information on technology of irradiation testing, specimen miniaturization, advanced methods of property measurement, safe windows for metal forming, and development of common materials property data base system. Both fusion and fission programs are being directed to development of clean steels with very low trace and tramp elements, characterization of microstructure and phase stability under irradiation, assessment of irradiation creep and swelling behaviour, studies on compatibility with helium and developing

  13. The abundant excess heat production during low energy nuclear reaction in the nano scale solid state the cold fusion, 14 years' legacy

    International Nuclear Information System (INIS)

    Woo, Tae Ho; Miley, George H.; Lipson, Andrei; Kim, Sung O.; Luo, Nie; Castano, Carlos H.

    2002-01-01

    The quite abundant excess heat and radioactive materials are found during the solid state reaction. This phenomenon has done during the Low Energy Nuclear Reaction (LENR) in the nano scale molecular structure electrodes and Hydrogen compound electrolytes. The Palladium (or Nickel) and Platinum are incorporated as the electrode and the Light Water (H 2 O) as the electrolyte. The excess heat was produced up to 40% in year 2001. The Alpha particles are also detected. The computer code, Coherent Lattice Accelerator Inter-Ionic Reaction Enhancer (CLAIRE) Code System, is constructed for the simulation. The 0.1 A of the distance between two the Hydrogen ion (proton) and Palladium nucleus is the critical point for the nuclear fusion reaction

  14. Fusion reactor start-up without an external tritium source

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, S., E-mail: Shanliang.Zheng@ccfe.ac.uk; King, D.B.; Garzotti, L.; Surrey, E.; Todd, T.N.

    2016-02-15

    Highlights: • Investigated the feasibility (including plasma physics, neutronics and economics) of starting a fusion reactor from running pure D–D fusion reactor to gradually move towards the D–T operation. • Proposed building up tritium from making use of neutrons generated by D–D fusion reactions. • Studied plasma physics feasibility for pure D–D operation and provided consistent fusion power and neutron yield in the plasma with different mixture of deuterium and tritium. • Discussed the economics aspect for operating a pure D–D fusion reactor towards a full-power D–T fusion reactor. - Abstract: It has long been recognised that the shortage of external tritium sources for fusion reactors using D–T, the most promising fusion fuel, requires all such fusion power plants (FPP) to breed their own tritium. It is also recognised that the initial start-up of a fusion reactor will require several kilograms of tritium within a scenario in which radioactive decay, ITER and subsequent demonstrator reactors are expected to have consumed most of the known tritium stockpile. To circumvent this tritium fuel shortage and ultimately achieve steady-state operation for a FPP, it is essential to first accumulate sufficient tritium to compensate for loss due to decay and significant retention in the materials in order to start a new FPP. In this work, we propose to accumulate tritium starting from D–D fusion reactions, since D exists naturally in water, and to gradually build up the D–T plasma targeted in fusion reactor designs. There are two likely D–D fusion reaction channels, (1) D + D → T + p, and (2) D + D → He3 + n. The tritium can be generated via the reaction channel ‘(1)’ and the 2.45 MeV neutrons from ‘(2)’ react with lithium-6 in the breeding blanket to produce more tritium to be fed back into plasma fuel. Quantitative evaluations are conducted for two blanket concepts to assess the feasibility and suitability of this approach to FPP

  15. Matriculation Research Report: Incomplete Grades; Data & Analysis.

    Science.gov (United States)

    Gerda, Joe

    The policy on incomplete grades at California's College of the Canyons states that incompletes may only be given under circumstances beyond students' control and that students must make arrangements with faculty prior to the end of the semester to clear the incomplete. Failure to complete an incomplete may result in an "F" grade. While…

  16. Magneized target fusion: An overview of the concept

    International Nuclear Information System (INIS)

    Kirkpatrick, R.C.

    1994-01-01

    Magnetized target fusion (MTF) seeks to take advantage of the reduction of thermal conductivity through the application of a strong magneticfield and thereby ease the requirements for reaching fusion conditions in a thermonuclear (TN) fusion fuel. A potentially important benefit of the strong field in the partial trapping of energetic charged particles to enhance energy deposition by the TN fusion reaction products. The essential physics is described. MTF appears to lead to fusion targets that require orders of magnitude less power and intensity for fusion ignition than currently proposed (unmagnetized) inertial confinement fusion (ICF) targets do, making some very energetic pulsed power drivers attractive for realizing controlled fusion

  17. LLL magnetic fusion research: the first 25 years

    International Nuclear Information System (INIS)

    Post, R.F.

    1978-01-01

    From its inception, the Laboratory has supported research directed at tapping controlled fusion. Our magnetic fusion energy program--now one of the major elements of the national fusion energy research effort--dates back to the Laboratory's founding in 1952. This article reviews the program's beginnings, progress, and present status in terms of its ultimate goal: to demonstrate a practical and economical means of generating power from controlled fusion reactions

  18. ACT-XN: Revised version of an activation calculation code for fusion reactor analysis. Supplement of the function for the sequential reaction activation by charged particles

    International Nuclear Information System (INIS)

    Yamauchi, Michinori; Sato, Satoshi; Nishitani, Takeo; Konno, Chikara; Hori, Jun-ichi; Kawasaki, Hiromitsu

    2007-09-01

    The ACT-XN is a revised version of the ACT4 code, which was developed in the Japan Atomic Energy Research Institute (JAERI) to calculate the transmutation, induced activity, decay heat, delayed gamma-ray source etc. for fusion devices. The ACT4 code cannot deal with the sequential reactions of charged particles generated by primary neutron reactions. In the design of present experimental reactors, the activation due to sequential reactions may not be of great concern as it is usually buried under the activity by primary neutron reactions. However, low activation material is one of the important factors for constructing high power fusion reactors in future, and unexpected activation may be produced through sequential reactions. Therefore, in the present work, the ACT4 code was newly supplemented with the calculation functions for the sequential reactions and renamed the ACT-XN. The ACT-XN code is equipped with functions to calculate effective cross sections for sequential reactions and input them in transmutation matrix. The FISPACT data were adopted for (x,n) reaction cross sections, charged particles emission spectra and stopping powers. The nuclear reaction chain data library were revised to cope with the (x,n) reactions. The charged particles are specified as p, d, t, 3 He(h) and α. The code was applied to the analysis of FNS experiment for LiF and Demo-reactor design with FLiBe, and confirmed that it reproduce the experimental values within 15-30% discrepancies. In addition, a notice was presented that the dose rate due to sequential reaction cannot always be neglected after a certain period cooling for some of the low activation material. (author)

  19. G protein betagamma-subunits activated by serotonin mediate presynaptic inhibition by regulating vesicle fusion properties.

    Science.gov (United States)

    Photowala, Huzefa; Blackmer, Trillium; Schwartz, Eric; Hamm, Heidi E; Alford, Simon

    2006-03-14

    Neurotransmitters are thought to be released as quanta, where synaptic vesicles deliver packets of neurotransmitter to the synaptic cleft by fusion with the plasma membrane. However, synaptic vesicles may undergo incomplete fusion. We provide evidence that G protein-coupled receptors inhibit release by causing such incomplete fusion. 5-hydroxytryptamine (5-HT) receptor signaling potently inhibits excitatory postsynaptic currents (EPSCs) between lamprey reticulospinal axons and their postsynaptic targets by a direct action on the vesicle fusion machinery. We show that 5-HT receptor-mediated presynaptic inhibition, at this synapse, involves a reduction in EPSC quantal size. Quantal size was measured directly by comparing unitary quantal amplitudes of paired EPSCs before and during 5-HT application and indirectly by determining the effect of 5-HT on the relationship between mean-evoked EPSC amplitude and variance. Results from FM dye-labeling experiments indicate that 5-HT prevents full fusion of vesicles. 5-HT reduces FM1-43 staining of vesicles with a similar efficacy to its effect on the EPSC. However, destaining of FM1-43-labeled vesicles is abolished by lower concentrations of 5-HT that leave a substantial EPSC. The use of a water-soluble membrane impermeant quenching agent in the extracellular space reduced FM1-43 fluorescence during stimulation in 5-HT. Thus vesicles contact the extracellular space during inhibition of synaptic transmission by 5-HT. We conclude that 5-HT, via free Gbetagamma, prevents the collapse of synaptic vesicles into the presynaptic membrane.

  20. Effects of successive critical distances in heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Lee, S.M.; Nakagawa, T.; Matsuse, T.

    1984-01-01

    The concept of Successive Critical Distances is presented. It appears that whether the fusion cross section is limited by compound nucleus or entrance channel properties depends on the degree of asymmetry of the fusing nuclei. Only in the near to symmetry case does the Statistical Yrast Line emerge as a limiting factor. Otherwise, the critical angular momentum for fusion is restricted by a critical distance

  1. Radiological findings and healing patterns of incomplete stress fractures of the pars interarticularis

    International Nuclear Information System (INIS)

    Dunn, Andrew J.; Campbell, Robert S.D.; Mayor, Peter E.; Rees, Dai

    2008-01-01

    The objective was to retrospectively record the CT and MRI features and healing patterns of acute, incomplete stress fractures of the pars interarticularis. The CT scans of 156 adolescents referred with suspected pars interarticularis stress fractures were reviewed. Patients with incomplete (grade 2) pars fractures were included in the study. Fractures were assessed on CT according to vertebral level, location of cortical involvement and direction of fracture propagation. MRI was also performed in 72 of the 156 cases. MRI images of incomplete fractures were assessed for the presence of marrow oedema and cortical integrity. Fracture healing patterns were characterised on follow-up CT imaging. Twenty-five incomplete fractures were identified in 23 patients on CT. All fractures involved the inferior or infero-medial cortex of the pars and propagated superiorly or superolaterally. Ninety-two percent of incomplete fractures demonstrated either complete or partial healing on follow-up imaging. Two (8%) cases progressed to complete fractures. Thirteen incomplete fractures in 11 patients confirmed on CT also had MRI, and 92% demonstrated oedema in the pars. Ten out of thirteen fractures (77%) showed a break in the infero-medial cortex with intact supero-lateral cortex, which correlated with the CT findings. MRI incorrectly graded one case as a complete (grade 3) fracture, and 2 cases as (grade 1) stress reaction. Six fractures had follow-up MRI, 67% showed partial or complete cortical healing, and the same number showed persistent marrow oedema. Incomplete fracture of the pars interarticularis represents a stage of the evolution of a complete stress fracture. The direction of fracture propagation is consistent, and complete healing can be achieved in most cases with appropriate clinical management. CT best demonstrates fracture size and extent, and is the most appropriate modality for follow-up. MRI is limited in its ability to fully depict the cortical integrity of

  2. Radiological findings and healing patterns of incomplete stress fractures of the pars interarticularis

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Andrew J.; Campbell, Robert S.D. [Royal Liverpool and Broadgreen University Teaching Hospitals, Department of Medical Imaging, Liverpool (United Kingdom); Mayor, Peter E. [Leighton Hospital, Department of Medical Imaging, Crewe, Cheshire (United Kingdom); Rees, Dai [Robert Jones and Agnes-Hunt Orthopaedic Hospital, Department of Orthopaedic Surgery, Oswestry, Shropshire (United Kingdom)

    2008-05-15

    The objective was to retrospectively record the CT and MRI features and healing patterns of acute, incomplete stress fractures of the pars interarticularis. The CT scans of 156 adolescents referred with suspected pars interarticularis stress fractures were reviewed. Patients with incomplete (grade 2) pars fractures were included in the study. Fractures were assessed on CT according to vertebral level, location of cortical involvement and direction of fracture propagation. MRI was also performed in 72 of the 156 cases. MRI images of incomplete fractures were assessed for the presence of marrow oedema and cortical integrity. Fracture healing patterns were characterised on follow-up CT imaging. Twenty-five incomplete fractures were identified in 23 patients on CT. All fractures involved the inferior or infero-medial cortex of the pars and propagated superiorly or superolaterally. Ninety-two percent of incomplete fractures demonstrated either complete or partial healing on follow-up imaging. Two (8%) cases progressed to complete fractures. Thirteen incomplete fractures in 11 patients confirmed on CT also had MRI, and 92% demonstrated oedema in the pars. Ten out of thirteen fractures (77%) showed a break in the infero-medial cortex with intact supero-lateral cortex, which correlated with the CT findings. MRI incorrectly graded one case as a complete (grade 3) fracture, and 2 cases as (grade 1) stress reaction. Six fractures had follow-up MRI, 67% showed partial or complete cortical healing, and the same number showed persistent marrow oedema. Incomplete fracture of the pars interarticularis represents a stage of the evolution of a complete stress fracture. The direction of fracture propagation is consistent, and complete healing can be achieved in most cases with appropriate clinical management. CT best demonstrates fracture size and extent, and is the most appropriate modality for follow-up. MRI is limited in its ability to fully depict the cortical integrity of

  3. What have fusion reactor studies done for you today?

    International Nuclear Information System (INIS)

    Kulchinski, G.L.

    1985-01-01

    The University of Wisconsin examines the fusion program and puts into perspective what return is being made on investments in fusion reactor studies. Illustations show financial support for fusion research from the four major programs, FY'82 expenditures on fusion research, and the total expenditures on fusion research since 1951. Topics discussed include the estimated number of scientists conducting fusion research, the conceptual design study of a fusion reactor, scoping study of a reactor, the chronology of fusion reactor design studies, published fusion reactor studies 1967-1983, conceptual fusion reactor design studies, STARFIRE reference design, MARS central cell, HYLIFE reaction chamber, and selected contributions of reactor design studies to base programs

  4. Nuclear dynamics around the barrier: from fusion to evaporation

    International Nuclear Information System (INIS)

    Simenel, Cedric

    2003-01-01

    This work is devoted to aspects of nuclear dynamics around the barrier. It is shown that for fusion reactions, the Coulomb field couples relative motion of nuclei to rotation of a deformed projectile independently of the energy and the charge of the nuclei. An experimental study of the reaction 6 He + 190 Os via gamma spectroscopy of product nuclei has shown that the break up of the 6 He is coupled to the relative motion too, a strong hindrance resulting in the fusion around and above the fusion barrier. The path to fusion after overcoming the barrier, especially the charge equilibration, have been studied in the framework of the TDHF theory via the preequilibrium GDR excited in N/Z asymmetric reactions. An application to formation of the super-heavy elements has been proposed. Finally, couplings between protons and neutrons have been shown up in mean field calculations. Their main expected effect is an emission of protons under the Coulomb barrier. (author)

  5. Dispersion relation approach to sub-barrier heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Franzin, V.L.M.; Hussein, M.S.

    1986-07-01

    With the aid of an inverse dispersion relation, which gives the imaginary part of the fusion inclusive polarization potential (IPP) in terms of the principal part integral involving the real part of the IPP, the sub-barrier fusion of heavy ions is discussed. The system 16 O+ A Sm is taken as an example. The reactive content of the extracted IPP is analysed within the coupled channels theory. (Author) [pt

  6. Warming up to cold fusion

    International Nuclear Information System (INIS)

    Storms, E.

    1994-01-01

    The idea that tabletop equipment at room temperature could produce nuclear fusion was widely rejected five years ago by the scientific community. Nevertheless, recent results from numerous labs show that a novel phenomena of some kind may indeed be occurring, though theorist are still groping for an explanation. Many aspects of the cold fusion effect are now reproducible if known procedures are used. Palladium, when reacted with enough deuterium, apparently converts to a special condition of matter in which various nuclear reactions--including deuterium-deuterium fusion--can occur despite the repulsive force of the two positive charged nuclei. These reactions can be made to proceed rapidly enough to produce measurable heat. Scientist have published several dozen models, ranging from highly analytical approaches to pictorial representations, to explain these events. Most theories address only the problem of overcoming the coulombic barrier--how it is possible for nuclei to overcome their natural repulsion for each other without an infusion of massive amounts of energy from the outside. None of the proposed explanations accounts for the full range of experimental observations. Nevertheless a workable theory is crucial if we ever hope to apply cold fusion

  7. Fusion reactors and the environment

    International Nuclear Information System (INIS)

    Hancox, R.

    1990-04-01

    Fusion power, based on the nuclear fusion of light elements to yield a net gain of energy, has the potential to extend the world's resources in a way which is environmentally attractive. Nevertheless, the easiest route to fusion - the reaction between deuterium and tritium - involves hazards from the use of tritium and the neutron activation of the structural materials. These hazards have been considered on the basis of simple conceptual reactor designs, both in relation to normal operation and decommissioning and to potential accident situations. Results from several studies are reviewed and suggest that fusion reactors appear to have an inherently lower environmental impact than fission reactors. However, the realization of this potential has yet to be demonstrated. (author)

  8. Trends in fusion reactor safety research

    International Nuclear Information System (INIS)

    Herring, J.S.; Holland, D.F.; Piet, S.J.

    1991-01-01

    Fusion has the potential to be an attractive energy source. From the safety and environmental perspective, fusion must avoid concerns about catastrophic accidents and unsolvable waste disposal. In addition, fusion must achieve an acceptable level of risk from operational accidents that result in public exposure and economic loss. Finally, fusion reactors must control routine radioactive effluent, particularly tritium. Major progress in achieving this potential rests on development of low-activation materials or alternative fuels. The safety and performance of various material choices and fuels for commercial fusion reactors can be investigated relatively inexpensively through reactor design studies. These studies bring together experts in a wide range of backgrounds and force the group to either agree on a reactor design or identify areas for further study. Fusion reactors will be complex with distributed radioactive inventories. The next generation of experiments will be critical in demonstrating that acceptable levels of safe operation can be achieved. These machines will use materials which are available today and for which a large database exists (e.g. for 316 stainless steel). Researchers have developed a good understanding of the risks associated with operation of these devices. Specifically, consequences from coolant system failures, loss of vacuum events, tritium releases, and liquid metal reactions have been studied. Recent studies go beyond next step designs and investigate commercial reactor concerns including tritium release and liquid metal reactions. 18 refs

  9. The abundant excess heat production during low energy nuclear reaction in the nano scale solid state the cold fusion, 14 years' legacy

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Tae Ho; Miley, George H.; Lipson, Andrei; Kim, Sung O.; Luo, Nie; Castano, Carlos H. [The University of Illinois, Urbana (United States)

    2002-05-01

    The quite abundant excess heat and radioactive materials are found during the solid state reaction. This phenomenon has done during the Low Energy Nuclear Reaction (LENR) in the nano scale molecular structure electrodes and Hydrogen compound electrolytes. The Palladium (or Nickel) and Platinum are incorporated as the electrode and the Light Water (H{sub 2}O) as the electrolyte. The excess heat was produced up to 40% in year 2001. The Alpha particles are also detected. The computer code, Coherent Lattice Accelerator Inter-Ionic Reaction Enhancer (CLAIRE) Code System, is constructed for the simulation. The 0.1 A of the distance between two the Hydrogen ion (proton) and Palladium nucleus is the critical point for the nuclear fusion reaction.

  10. Mission to Mars by catalyzed nuclear reactions of the commercialized cold fusion power

    International Nuclear Information System (INIS)

    Woo, Tae Ho

    2016-01-01

    The chemical compound source is deficient to reach to the power as much as the journey to Mars, unless the massive equipment is installed like the nuclear fusion reactor. However, there is very significant limitations of making up the facility due to the propellant power. Therefore, the light and cheap energy source, Low energy nuclear reactions (LENRs), powered rocket has been proposed. In this paper, the power conditions by LENRs are analyzed. After the successful Apollo mission to Moon of the National Aeronautics and Space Administration (NASA) in the U.S. government, the civilian companies have proposed for the manned mission to Mars for the commercial journey purposes. The nuclear power has been a critical issue for the energy source in the travel, especially, by the LENR of LENUCO, Champaign, USA. As the velocity of the rocket increases, the mass flow rate decreases. It could be imaginable to take the reasonable velocity of spacecraft. The energy of the travel system is and will be created for the better one in economical and safe method. There is the imagination of boarding pass for spacecraft ticket shows the selected companies of cold fusion products. In order to solve the limitations of the conventional power sources like the chemical and solar energies, it is reasonable to design LENR concept. Since the economical and safe spacecraft is very important in the long journey on and beyond the Mars orbit, a new energy source, LENR, should be studied much more

  11. Mission to Mars by catalyzed nuclear reactions of the commercialized cold fusion power

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Tae Ho [Yonsei University, Wonju (Korea, Republic of)

    2016-05-15

    The chemical compound source is deficient to reach to the power as much as the journey to Mars, unless the massive equipment is installed like the nuclear fusion reactor. However, there is very significant limitations of making up the facility due to the propellant power. Therefore, the light and cheap energy source, Low energy nuclear reactions (LENRs), powered rocket has been proposed. In this paper, the power conditions by LENRs are analyzed. After the successful Apollo mission to Moon of the National Aeronautics and Space Administration (NASA) in the U.S. government, the civilian companies have proposed for the manned mission to Mars for the commercial journey purposes. The nuclear power has been a critical issue for the energy source in the travel, especially, by the LENR of LENUCO, Champaign, USA. As the velocity of the rocket increases, the mass flow rate decreases. It could be imaginable to take the reasonable velocity of spacecraft. The energy of the travel system is and will be created for the better one in economical and safe method. There is the imagination of boarding pass for spacecraft ticket shows the selected companies of cold fusion products. In order to solve the limitations of the conventional power sources like the chemical and solar energies, it is reasonable to design LENR concept. Since the economical and safe spacecraft is very important in the long journey on and beyond the Mars orbit, a new energy source, LENR, should be studied much more.

  12. Commissioning of a DT fusion reactor without external supply of tritium

    International Nuclear Information System (INIS)

    Asaoka, Y.; Konishi, S.; Nishio, S.; Hiwatari, R.; Okano, K.; Yoshida, T.; Tomabechi, K.

    2001-01-01

    Commissioning of a DT fusion reactor without external supply of tritium is discussed. The DD reactions in a DT-oriented fusion reactor with external power injection by neutral beams produce tritium and neutrons. Tritium produced by the DD reaction together with that produced in the blanket by the 2.45 MeV neutron is re-circulated into the plasma. Then, the DT reaction rate increases gradually, as tritium concentration in plasma builds up towards the level of nominal operation. Time required to reach the nominal operational condition, i.e. 50 % tritium in plasma, is estimated with assumptions based on a model of fusion power plant. As a result, the start-up period of a DT fusion reactor without external supply of tritium is estimated to be approximately 55 days, with the plasma parameters of CREST having a high performance blanket and tritium processing systems. Major factors to determine the start-up period are DD and DT reaction rates, net tritium breeding gain of the plant and dead inventory in/on facing materials. Elimination of a constraint for fusion reactor deployment and operation without any tritium transportation in and out of plant through its entire life may be possible. (author)

  13. Advanced fuels for nuclear fusion reactors

    International Nuclear Information System (INIS)

    McNally, J.R. Jr.

    1974-01-01

    Should magnetic confinement of hot plasma prove satisfactory at high β (16 πnkT//sub B 2 / greater than 0.1), thermonuclear fusion fuels other than D.T may be contemplated for future fusion reactors. The prospect of the advanced fusion fuels D.D and 6 Li.D for fusion reactors is quite promising provided the system is large, well reflected and possesses a high β. The first generation reactions produce the very active, energy-rich fuels t and 3 He which exhibit a high burnup probability in very hot plasmas. Steady state burning of D.D can ensue in a 60 kG field, 5 m reactor for β approximately 0.2 and reflectivity R/sub mu/ = 0.9 provided the confinement time is about 38 sec. The feasibility of steady state burning of 6 Li.D has not yet been demonstrated but many important features of such systems still need to be incorporated in the reactivity code. In particular, there is a need for new and improved nuclear cross section data for over 80 reaction possibilities

  14. A Simulation Study for Radiation Treatment Planning Based on the Atomic Physics of the Proton-Boron Fusion Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sunmi; Yoon, Do-Kun; Shin, Han-Back; Jung, Joo-Young; Kim, Moo-Sub; Kim, Kyeong-Hyeon; Jang, Hong-Seok; Suh, Tae Suk [the Catholic University of Korea, Seoul (Korea, Republic of)

    2017-03-15

    The purpose of this research is to demonstrate, based on a Monte Carlo simulation code, the procedure of radiation treatment planning for proton-boron fusion therapy (PBFT). A discrete proton beam (60 - 120 MeV) relevant to the Bragg peak was simulated using a Monte Carlo particle extended (MCNPX, Ver. 2.6.0, National Laboratory, Los Alamos NM, USA) simulation code. After computed tomography (CT) scanning of a virtual water phantom including air cavities, the acquired CT images were converted using the simulation source code. We set the boron uptake regions (BURs) in the simulated water phantom to achieve the proton-boron fusion reaction. Proton sources irradiated the BUR, in the phantom. The acquired dose maps were overlapped with the original CT image of the phantom to analyze the dose volume histogram (DVH). We successfully confirmed amplifications of the proton doses (average: 130%) at the target regions. From the DVH result for each simulation, we acquired a relatively accurate dose map for the treatment. A simulation was conducted to characterize the dose distribution and verify the feasibility of proton boron fusion therapy (PBFT). We observed a variation in proton range and developed a tumor targeting technique for treatment that was more accurate and powerful than both conventional proton therapy and boron-neutron capture therapy.

  15. LLNL nuclear data libraries used for fusion calculations

    International Nuclear Information System (INIS)

    Howerton, R.J.

    1984-01-01

    The Physical Data Group of the Computational Physics Division of the Lawrence Livermore National Laboratory has as its principal responsibility the development and maintenance of those data that are related to nuclear reaction processes and are needed for Laboratory programs. Among these are the Magnetic Fusion Energy and the Inertial Confinement Fusion programs. To this end, we have developed and maintain a collection of data files or libraries. These include: files of experimental data of neutron induced reactions; an annotated bibliography of literature related to charged particle induced reactions with light nuclei; and four main libraries of evaluated data. We also maintain files of calculational constants developed from the evaluated libraries for use by Laboratory computer codes. The data used for fusion calculations are usually these calculational constants, but since they are derived by prescribed manipulation of evaluated data this discussion will describe the evaluated libraries

  16. Correlations between transfer and fusion in heavy ion collisions at the Coulomb barrier

    International Nuclear Information System (INIS)

    Bellwied, R.

    1989-03-01

    For the fusion of heavy atomic nuclei the nuclear-charge product exceeds Z 1 Z 2 =1600 in experiments at the Coulomb barrier a dynamical hindrance was detected. For the study of all binary reaction channels first 86 Kr induced reactions with 76 Ge, 104 Ru, and 130 Te were radiochemically studied. The relative to the fusion still unhindered system Kr+Ge shows beside the fusion only the transfer of few nucleons between projectile and target. In the reactions with Ru and Te (onsetting fusion hindrance) goes indeed a certain part (about 20%) of the missing fusion cross section in reactions with large mass flux, on the other hand however a sudden increasing of the quasi-elastic transfer of few nucleons strikes which fits well into the trend of the literature data for lighter and heavier systems and signalizes a sharply localized correlation between the vanishing of the fusion and the increasing of the transfer. In order to study further this threshold behaviour and to get additional kinematical informations on the binary reaction channels the reactions 96 Zr+ 90 Zr and 124 Sn+ 96 Zr were measured at the magnetic spectrometer of the GSI. With the spectrometer it is contrarily to the radiochemical experiments possible to determine fourfold differential cross section distributions. The sudden increasing of the cross section for quasi-elastic transfer at the threshold for fusion hindrance is completely confirmed whereby from measurements of the energy loss in the exit channel follows that (with lower weight) also complex transfer channels with essential energy damping are formed. By these experiments it has been shown for the first time that the dynamical fusion hindrance already onsets before the collisional partners reach the barrier. (orig./HSI) [de

  17. Heavy-ion accelerator research for inertial fusion

    International Nuclear Information System (INIS)

    1987-08-01

    Thermonuclear fusion offers a most attractive long-term solution to the problem of future energy supplies: The fuel is virtually inexhaustible and the fusion reaction is notably free of long-lived radioactive by-products. Also, because the fuel is in the form of a plasma, there is no solid fuel core that could melt down. The DOE supports two major fusion research programs to exploit these virtues, one based on magnetic confinement and a second on inertial confinement. One part of the program aimed at inertial fusion is known as Heavy Ion Fusion Accelerator Research, or HIFAR. In this booklet, the aim is to place this effort in the context of fusion research generally, to review the brief history of heavy-ion fusion, and to describe the current status of the HIFAR program

  18. Quark-level analogue of nuclear fusion with doubly heavy baryons.

    Science.gov (United States)

    Karliner, Marek; Rosner, Jonathan L

    2017-11-01

    The essence of nuclear fusion is that energy can be released by the rearrangement of nucleons between the initial- and final-state nuclei. The recent discovery of the first doubly charmed baryon , which contains two charm quarks (c) and one up quark (u) and has a mass of about 3,621 megaelectronvolts (MeV) (the mass of the proton is 938 MeV) also revealed a large binding energy of about 130 MeV between the two charm quarks. Here we report that this strong binding enables a quark-rearrangement, exothermic reaction in which two heavy baryons (Λ c ) undergo fusion to produce the doubly charmed baryon and a neutron n (), resulting in an energy release of 12 MeV. This reaction is a quark-level analogue of the deuterium-tritium nuclear fusion reaction (DT → 4 He n). The much larger binding energy (approximately 280 MeV) between two bottom quarks (b) causes the analogous reaction with bottom quarks () to have a much larger energy release of about 138 MeV. We suggest some experimental setups in which the highly exothermic nature of the fusion of two heavy-quark baryons might manifest itself. At present, however, the very short lifetimes of the heavy bottom and charm quarks preclude any practical applications of such reactions.

  19. Overview of fusion reactor safety

    International Nuclear Information System (INIS)

    Cohen, S.; Crocker, J.G.

    1981-01-01

    Use of deuterium-tritium burning fusion reactors requires examination of several major safety and environmental issues: (1) tritium inventory control, (2) neutron activation of structural materials, fluid streams and reactor hall environment, (3) release of radioactivity from energy sources including lithium spill reactions, superconducting magnet stored energy release, and plasma disruptions, (4) high magnetic and electromagnetic fields associated with fusion reactor superconducting magnets and radio frequency heating devices, and (5) handling and disposal of radioactive waste. Early recognition of potential safety problems with fusion reactors provides the opportunity for improvement in design and materials to eliminate or greatly reduce these problems. With an early start in this endeavor, fusion should be among the lower risk technologies for generation of commercial electrical power

  20. Reactions with weakly bound nuclei at near barrier energies

    International Nuclear Information System (INIS)

    Nanal, Vandana

    2014-01-01

    In reactions with weakly bound nuclei, the effect of breakup on fusion process has attracted much attention in recent years. The experimental study shows that breakup channel leads to suppression of complete fusion at above barrier energies due to loss of flux. The fusion barrier distribution can provide a further insight into understanding the influence of coupling to the breakup channels. Similar information could be obtained from the elastic and quasielastic (QEL) scattering because of the conservation of the reaction flux (i.e. R+T= 1), where R is the reflection probability and T is the transmission probability. Thus, quasi-elastic scattering at backward angles is the counterpart of the fusion process and it is expected that the barrier distributions extracted from two processes, namely, QEL and fusion should be similar. While this is true for tightly bound reaction systems, in reactions involving weakly bound projectiles significant differences have been observed for QEL barrier distributions with and without inclusion of breakup processes. This talk will present the recent results for fusion and quasi-elastic scattering in "6","7Li + "1"9"7Au system. Developmental efforts towards a momentum achromatic separator, MARIE, to extract projectile-like secondary ion beams following the reactions of heavy-ion beams from superconducting LINAC booster at Mumbai will also be presented. (author)

  1. Small mirror fusion reactors

    International Nuclear Information System (INIS)

    Carlson, G.A.; Schultz, K.R.; Smith, A.C. Jr.

    1978-01-01

    Basic requirements for the pilot plants are that they produce a net product and that they have a potential for commercial upgrade. We have investigated a small standard mirror fusion-fission hybrid, a two-component tandem mirror hybrid, and two versions of a field-reversed mirror fusion reactor--one a steady state, single cell reactor with a neutral beam-sustained plasma, the other a moving ring field-reversed mirror where the plasma passes through a reaction chamber with no energy addition

  2. Studies of complex fragment emission in heavy ion reactions

    International Nuclear Information System (INIS)

    Charity, R.J.; Sobotka, L.G.

    1992-01-01

    Our work involves the study of intermediate energy heavy-ion nuclear reactions. This work has two foci. On the one hand, we desire to learn about the properties of nuclear matter under abnormal conditions, in this energy domain, predominately low densities. This purpose runs abreast of the second, which is the study of the relevant reaction mechanisms. The two objectives are inexorably linked because our experimental laboratory for studying nuclear matter properties is a dynamic one. We are forced to ask how nuclear matter properties, such as phase transitions, are reflected in the dynamics of the reactions. It may be that irrefutable information about nuclear matter will not be extracted from the reaction work. Nevertheless, we are compelled to undertake this effort not only because it is the only game in town and as yet we do not know that information cannot be extracted, but also because of our second objective. The process leads to an understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. Our program has been: To study energy, mass, and angular momentum deposition by studying incomplete fusion reactions. To gain confidence that we understand how highly excited systems decompose by studying all emissions from the highly excited systems. To push these kinds of studies into the intermediate energy domain, with excitation function studies. And attempt to learn about the dynamics of the decays using particle-particle correlations. In the last effort, we have decided to focus on simple systems, where we believe, definitive statements are possible. These avenues of research share a common theme, large complex fragment production

  3. Fusion Power measurement at ITER

    Energy Technology Data Exchange (ETDEWEB)

    Bertalot, L.; Barnsley, R.; Krasilnikov, V.; Stott, P.; Suarez, A.; Vayakis, G.; Walsh, M. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France)

    2015-07-01

    Nuclear fusion research aims to provide energy for the future in a sustainable way and the ITER project scope is to demonstrate the feasibility of nuclear fusion energy. ITER is a nuclear experimental reactor based on a large scale fusion plasma (tokamak type) device generating Deuterium - Tritium (DT) fusion reactions with emission of 14 MeV neutrons producing up to 700 MW fusion power. The measurement of fusion power, i.e. total neutron emissivity, will play an important role for achieving ITER goals, in particular the fusion gain factor Q related to the reactor performance. Particular attention is given also to the development of the neutron calibration strategy whose main scope is to achieve the required accuracy of 10% for the measurement of fusion power. Neutron Flux Monitors located in diagnostic ports and inside the vacuum vessel will measure ITER total neutron emissivity, expected to range from 1014 n/s in Deuterium - Deuterium (DD) plasmas up to almost 10{sup 21} n/s in DT plasmas. The neutron detection systems as well all other ITER diagnostics have to withstand high nuclear radiation and electromagnetic fields as well ultrahigh vacuum and thermal loads. (authors)

  4. Excitation functions for some evaporation residues identified in the interaction of 20Ne and 93Nb at moderate excitation energies

    International Nuclear Information System (INIS)

    Agarwal, Avinash; Rizvi, I.A.; Gupta, Meenal; Ahamad, Tauseef; Ghugre, S.S.; Sinha, A.K.; Chaubey, A.K.

    2008-01-01

    With the motivation of studying the complete and incomplete fusion reactions, excitation functions for the reactions 93 Nb(Ne, p2n) 110 Sn, 93 Nb(Ne, 2pn) 110 In, 93 Nb(Ne, 2p2n) 109 In, 93 Nb(Ne, αn) 108 In, 93 Nb(Neα2n) 107 In and 93 Nb(Ne, α p n) 107 Cd have been measured at the incident energy ranging from 91.4 MeV - 145 MeV. The well established activation technique followed by off line high purity gamma- ray spectroscopy was employed. The measured excitation functions were compared with the statistical model calculations by using the codes ALICE-91 and Pace-4. The effect of variation of different parameters including level density parameter involved in these codes has also been studied. Excellent agreement was found between theoretical and experimental values in some of the fusion evaporation reaction channels. However, significant enhancement of cross-section observed in α-emission channels may be due to incomplete fusion process. (author)

  5. Some considerations of ''cold fusion'' including the calculation of fusion rates in molecules of hydrogen isotopes

    International Nuclear Information System (INIS)

    Cowley, S.C.; Kulsrud, R.M.

    1989-11-01

    We calculate the fusion reaction rates in molecules of hydrogen isotopes. The rates are calculated analytically (for the first time) as an asymptotic expansion in the ratio of the electron mass to the reduced mass of the nucleii. The fusion rates of the P-D, D-D, and D-T reactions are given for a variable electron mass by a simple analytic formula. However, we do not know any mechanism by which a sufficiently localized electron in solid can have an 'effective mass' large enough to explain the result of Fleischman and Pons (FP). This calculation indicates that P-D rates should exceed D-D rates for D-D fusion rates less than approximately 10 -23 per molecule per second. The D-D fusion rate is enhanced by a factor of 10 5 at 10,000 degree K if the excited vibrational states are populated with a Boltzmann distribution and the rotational excitations suppressed. The suggestion that experimental results could be explained by bombardment of cold deuterons by kilovolt deuterons is shown to be an unlikely from an energetic point of view. 12 refs., 3 figs., 1 tab

  6. Laser drivers for inertial confinement fusion

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1983-01-01

    Inertial Confinement Fusion (ICF) is the technology that we are developing to access the vast stored energy potential of deuterium fuel located in the world's water supply. This form of fusion is accomplished by compressing and heating small volumes of D-T fuel to very high temperatures (greater than 100M 0 C) and to very high densities (greater than 1000 times the normal liquid density). Under these fuel conditions, a thermonuclear reaction can occur, leading to a net energy release compared to the energy used to heat the fuel initially. To accomplish the condition where fusion reactions begin, effective drivers are required. These are lasers or particle beam accelerators which can provide greater than 10 14 W/cm 2 over millimeter scale targets with an appropriately programmed intensity vs time. At present, we are using research lasers to obtain an understanding of the physics and engineering of fuel compression

  7. Low-energy nuclear fusion data and their relation to magnetic and laser fusion

    International Nuclear Information System (INIS)

    Jarmie, N.

    1980-04-01

    The accuracy of the basic fusion data for the T(d,n) 4 He, 3 He(d,p) 4 He, T(t,2n) 4 He, D(d,n) 3 He, and D(d,p)T reactions was investigated in the 10- to 100-keV bombarding energy region, and the effects of inaccuracies on the design of fusion reactors were assessed. The data base for these reactions [particularly, the most critical T(d,n) 4 He reaction] rests on 25-year-old experiments the accuracy (often assumed to be +- 5%) of which has rarely been questioned: yet, in all except the d + d reactions, there are significant differences among data sets. The errors in the basic data sets may be considerably larger than previously expected, and the effect on design calculations should be significant. Much of the trouble apparently lies in the accuracy of the energy measurements, which are difficult at low energies. Systematic errors of up to 50% are possible in the reactivity values of the present T(d,n) 4 He data base. The errors in the reactivity will propagate proportionately into the errors in fusion probabilities in reactor calculations. 3 He(d,p) 4 He reaction cross sections could be in error by as much as 50% in the low-energy region. The D(d,n) 3 He and D(d,p)T cross sections appear to be well known and consistent. The T(t,2n) 4 He cross section is poorly known and may be subject to large systematic errors. Improved absolute measurements for all the reactions in the low bombarding energy region (10 to 100 keV) are needed, but until they are done, the data sets should be left as they are [except for T(t,2n) 4 He data, which could be lowered by about 50%]. The apparent uncertainties of these data sets should be kept in mind. 14 figures

  8. Tore supra: towards the 'long time' fusion. Press journey

    International Nuclear Information System (INIS)

    2008-01-01

    After a recall of the interest in the fusion for the development of energy sources, the document presents the fusion from the solar reaction to the nuclear fusion in laboratory. Then it discusses the great challenges of this technology and the Tore Supra installation. The last part is devoted to ITER and DEMO projects. (A.L.B.)

  9. Public acceptance of fusion energy and scientific feasibility of a fusion reactor. Spin-off effects of fusion research and development

    International Nuclear Information System (INIS)

    Morino, Nobuyuki; Ogawa, Yuichi

    1998-01-01

    It is observed that new and sophisticated technologies developed through research and development in relation to magnetic confinement fusion have been transferred to other industrial and scientific fields with remarkable spin-off effects. Approximately 10 years ago, the Japan Atomic Industrial Forum (JAIF) has investigated technical transfer and spin-off effects of fusion technologies developed in Japan. The essence of the results of this investigation as well as high technologies developed in the last decade, some of which are in the early stage of technical spin-off, are described. It is additionally explained that independent technical development conducted by our country as well as by engineers themselves is important in achieving effective spin-off. An outline of scientific spin-off effects is also described, including utilization technologies of fusion reactions besides those for energy production purposes, the progress of scientific understanding in the course of fusion research, and scientific information transfer and communication with other fields. (author)

  10. Spectator invariance test in the study of the Trojan Horse Method 6,7Li fusion reactions via the Trojan Horse Method

    Directory of Open Access Journals (Sweden)

    Li C.

    2011-10-01

    Full Text Available Fusion reactions play a crucial role for several astrophysical scenarios. At the low energies typical of such environments direct measurements of reaction cross sections are very difficult, and even sometimes impossible. In such cases the use of indirect methods can give a substantial help. The Trojan Horse Method (THM is based on the quasi-free break-up of a nucleus, which can be described in terms of a cluster structure. In such applications the independence of THM results with different break-up schemes, was tested using the quasi free3 He(6Li,ααH and 3He(7Li,αα2H reactions. Results were then compared with the direct behaviours obtained from available data as well as with the cross sections extracted from previous indirect investigations of the same binary reactions using a different nuclide as a Trojan Horse nucleus.

  11. FENDL/C-2.0. Charged-particle reaction data library for fusion applications. Version 1 of March 1997. Data extracted from ENDF/B-6 evaluations. Summary documentation

    International Nuclear Information System (INIS)

    Pashchenko, A.B.; Wienke, H.

    1997-01-01

    This document describes the FENDL/C-2.0 charged-particle reaction data library which is a sublibrary of FENDL-2, the evaluated nuclear data library for fusion applications. This file contains evaluated data in ENDF-6 format for the D(d,n), D(d,p), T(d,n), T(t,2n), He-3(d,p) reactions. The processed information, i.e. Maxwellian-averaged reaction rates, and related quantities, calculated from reaction cross-sections, are also included. The data are available from the Nuclear Data Section online via INTERNET by FTP command, or on magnetic tape upon request. (author)

  12. Fusion peptides from oncogenic chimeric proteins as putative specific biomarkers of cancer.

    Science.gov (United States)

    Conlon, Kevin P; Basrur, Venkatesha; Rolland, Delphine; Wolfe, Thomas; Nesvizhskii, Alexey I; MacCoss, Michael J; Lim, Megan S; Elenitoba-Johnson, Kojo S J

    2013-10-01

    Chromosomal translocations encoding chimeric fusion proteins constitute one of the most common mechanisms underlying oncogenic transformation in human cancer. Fusion peptides resulting from such oncogenic chimeric fusions, though unique to specific cancer subtypes, are unexplored as cancer biomarkers. Here we show, using an approach termed fusion peptide multiple reaction monitoring mass spectrometry, the direct identification of different cancer-specific fusion peptides arising from protein chimeras that are generated from the juxtaposition of heterologous genes fused by recurrent chromosomal translocations. Using fusion peptide multiple reaction monitoring mass spectrometry in a clinically relevant scenario, we demonstrate the specific, sensitive, and unambiguous detection of a specific diagnostic fusion peptide in clinical samples of anaplastic large cell lymphoma, but not in a diverse array of benign lymph nodes or other forms of primary malignant lymphomas and cancer-derived cell lines. Our studies highlight the utility of fusion peptides as cancer biomarkers and carry broad implications for the use of protein biomarkers in cancer detection and monitoring.

  13. Cross Sections Calculations of ( d, t) Nuclear Reactions up to 50 MeV

    Science.gov (United States)

    Tel, E.; Yiğit, M.; Tanır, G.

    2013-04-01

    In nuclear fusion reactions two light atomic nuclei fuse together to form a heavier nucleus. Fusion power is the power generated by nuclear fusion processes. In contrast with fission power, the fusion reaction processes does not produce radioactive nuclides. The fusion will not produce CO2 or SO2. So the fusion energy will not contribute to environmental problems such as particulate pollution and excessive CO2 in the atmosphere. Fusion powered electricity generation was initially believed to be readily achievable, as fission power had been. However, the extreme requirements for continuous reactions and plasma containment led to projections being extended by several decades. In 2010, more than 60 years after the first attempts, commercial power production is still believed to be unlikely before 2050. Although there have been significant research and development studies on the inertial and magnetic fusion reactor technology, there is still a long way to go to penetrate commercial fusion reactors to the energy market. In the fusion reactor, tritium self-sufficiency must be maintained for a commercial power plant. Therefore, for self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. Working out the systematics of ( d, t) nuclear reaction cross sections is of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at different energies. Since the experimental data of charged particle induced reactions are scarce, self-consistent calculation and analyses using nuclear theoretical models are very important. In this study, ( d, t) cross sections for target nuclei 19F, 50Cr, 54Fe, 58Ni, 75As, 89Y, 90Zr, 107Ag, 127I, 197Au and 238U have been investigated up to 50 MeV deuteron energy. The excitation functions for ( d, t) reactions have been calculated by pre-equilibrium reaction mechanism. Calculation results have been also compared with the available measurements in

  14. Tore supra: towards the 'long time' fusion. Press journey; Tore Supra: vers la fusion 'longue duree'. Voyage de presse

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    After a recall of the interest in the fusion for the development of energy sources, the document presents the fusion from the solar reaction to the nuclear fusion in laboratory. Then it discusses the great challenges of this technology and the Tore Supra installation. The last part is devoted to ITER and DEMO projects. (A.L.B.)

  15. Fusion probability and survivability in estimates of heaviest nuclei production

    International Nuclear Information System (INIS)

    Sagaidak, Roman

    2012-01-01

    A number of theoretical models have been recently developed to predict production cross sections for the heaviest nuclei in fusion-evaporation reactions. All the models reproduce cross sections obtained in experiments quite well. At the same time they give fusion probability values P fus ≡ P CN differed within several orders of the value. This difference implies a corresponding distinction in the calculated values of survivability. The production of the heaviest nuclei (from Cm to the region of superheavy elements (SHE) close to Z = 114 and N = 184) in fusion-evaporation reactions induced by heavy ions has been considered in a systematic way within the framework of the barrier-passing (fusion) model coupled with the standard statistical model (SSM) of the compound nucleus (CN) decay. Both models are incorporated into the HIVAP code. Available data on the excitation functions for fission and evaporation residues (ER) produced in very asymmetric combinations can be described rather well within the framework of HIVAP. Cross-section data obtained in these reactions allow one to choose model parameters quite definitely. Thus one can scale and fix macroscopic (liquid-drop) fission barriers for nuclei involved in the evaporation-fission cascade. In less asymmetric combinations (with 22 Ne and heavier projectiles) effects of fusion suppression caused by quasi-fission are starting to appear in the entrance channel of reactions. The P fus values derived from the capture-fission and fusion-fission cross-sections obtained at energies above the Bass barrier were plotted as a function of the Coulomb parameter. For more symmetric combinations one can deduce the P fus values semi-empirically, using the ER and fission excitation functions measured in experiments, and applying SSM model with parameters obtained in the analysis of a very asymmetric combination leading to the production of (nearly) the same CN, as was done for reactions leading to the pre-actinide nuclei formation

  16. Controlled thermonuclear fusion reactors

    International Nuclear Information System (INIS)

    Walstrom, P.L.

    1976-01-01

    Controlled production of energy by fusion of light nuclei has been the goal of a large portion of the physics community since the 1950's. In order for a fusion reaction to take place, the fuel must be heated to a temperature of 100 million degrees Celsius. At this temperature, matter can exist only in the form of an almost fully ionized plasma. In order for the reaction to produce net power, the product of the density and energy confinement time must exceed a minimum value of 10 20 sec m -3 , the so-called Lawson criterion. Basically, two approaches are being taken to meet this criterion: inertial confinement and magnetic confinement. Inertial confinement is the basis of the laser fusion approach; a fuel pellet is imploded by intense laser beams from all sides and ignites. Magnetic confinement devices, which exist in a variety of geometries, rely upon electromagnetic forces on the charged particles of the plasma to keep the hot plasma from expanding. Of these devices, the most encouraging results have been achieved with a class of devices known as tokamaks. Recent successes with these devices have given plasma physicists confidence that scientific feasibility will be demonstrated in the next generation of tokamaks; however, an even larger effort will be required to make fusion power commercially feasible. As a result, emphasis in the controlled thermonuclear research program is beginning to shift from plasma physics to a new branch of nuclear engineering which can be called fusion engineering, in which instrumentation and control engineers will play a major role. Among the new problem areas they will deal with are plasma diagnostics and superconducting coil instrumentation

  17. Incomplete information and fractal phase space

    International Nuclear Information System (INIS)

    Wang, Qiuping A.

    2004-01-01

    The incomplete statistics for complex systems is characterized by a so called incompleteness parameter ω which equals unity when information is completely accessible to our treatment. This paper is devoted to the discussion of the incompleteness of accessible information and of the physical signification of ω on the basis of fractal phase space. ω is shown to be proportional to the fractal dimension of the phase space and can be linked to the phase volume expansion and information growth during the scale refining process

  18. Effect of a generalized particle momentum distribution on plasma nuclear fusion rates

    International Nuclear Information System (INIS)

    Kim, Yeong E.; Zubarev, Alexander L.

    2006-01-01

    We investigate the effect of a generalized particle momentum distribution derived by Galitskii and Yakimets (GY) on nuclear reaction rates in plasma. We derive an approximate semi-analytical formula for nuclear fusion reaction rate between nuclei in a plasma (quantum plasma nuclear fusion; or QPNF). The QPNF formula is applied to calculate deuteron-deuteron fusion rate in a plasma, and the results are compared with the results calculated with the conventional Maxwell-Boltzmann velocity distribution. As an application, we investigate the deuteron-deuteron fusion rate for mobile deuterons in a deuterated metal/alloy. The calculated deuteron-deuteron fusion rates at low energies are enormously enhanced due to the modified tail of the GY's generalized momentum distribution. Our preliminary estimates indicate also that the deuteron-lithium (D+Li) fusion rate and the proton-lithium (p+Li) fusion rate in a metal/alloy at ambient temperatures are also substantially enhanced. (author)

  19. The existence and characterization of self-sustaining multiplicative fusion and fission reaction chains

    International Nuclear Information System (INIS)

    Harms, A.A.; Heindler, M.

    1980-01-01

    The mathematical-physical similarities and differences between fusion and fission multiplication processes are investigated. It is shown that advanced fusion cycles can sustain excursion tendencies which are essentially analogous to conventional fission cycles. The result that fission excursions are unbounded and that fusion excursions eventually attain an asymptote represents a significant distinction between these fundamental self-sustaining nuclear multiplicative chains. (Auth.)

  20. Membrane fusion and exocytosis.

    Science.gov (United States)

    Jahn, R; Südhof, T C

    1999-01-01

    Membrane fusion involves the merger of two phospholipid bilayers in an aqueous environment. In artificial lipid bilayers, fusion proceeds by means of defined transition states, including hourglass-shaped intermediates in which the proximal leaflets of the fusing membranes are merged whereas the distal leaflets are separate (fusion stalk), followed by the reversible opening of small aqueous fusion pores. Fusion of biological membranes requires the action of specific fusion proteins. Best understood are the viral fusion proteins that are responsible for merging the viral with the host cell membrane during infection. These proteins undergo spontaneous and dramatic conformational changes upon activation. In the case of the paradigmatic fusion proteins of the influenza virus and of the human immunodeficiency virus, an amphiphilic fusion peptide is inserted into the target membrane. The protein then reorients itself, thus forcing the fusing membranes together and inducing lipid mixing. Fusion of intracellular membranes in eukaryotic cells involves several protein families including SNAREs, Rab proteins, and Sec1/Munc-18 related proteins (SM-proteins). SNAREs form a novel superfamily of small and mostly membrane-anchored proteins that share a common motif of about 60 amino acids (SNARE motif). SNAREs reversibly assemble into tightly packed helical bundles, the core complexes. Assembly is thought to pull the fusing membranes closely together, thus inducing fusion. SM-proteins comprise a family of soluble proteins that bind to certain types of SNAREs and prevent the formation of core complexes. Rab proteins are GTPases that undergo highly regulated GTP-GDP cycles. In their GTP form, they interact with specific proteins, the effector proteins. Recent evidence suggests that Rab proteins function in the initial membrane contact connecting the fusing membranes but are not involved in the fusion reaction itself.

  1. Fusion barrier distributions - What have we learned?

    International Nuclear Information System (INIS)

    Hinde, D. J.; Dasgupta, M.

    1998-01-01

    The study of nuclear fusion received a strong impetus from the realisation that an experimental fusion barrier distribution could be determined from precisely measured fusion cross-sections. Experimental data for different reactions have shown in the fusion barrier distributions clear signatures of a range of nuclear excitations, for example the effects of static quadrupole and hexadecapole deformations, single- and double-phonon states, transfer of nucleons, and high-lying excited states. The improved understanding of fusion barrier distributions allows more reliable prediction of fusion angular momentum distributions, which aids interpretation of fission probabilities and fission anisotropies, and understanding of the population of super-deformed bands for nuclear structure studies. Studies of the relationship between the fusion barrier distribution and the extra-push energy should improve our understanding of the mechanism of the extra-push effect, and may help to predict new ways of forming very heavy or super-heavy nuclei

  2. Solenoidal fusion system

    International Nuclear Information System (INIS)

    Linlor, W.I.

    1980-01-01

    This invention discloses apparatus and methods to produce nuclear fusion utilizing fusible material in the form of high energy ion beams confined in magnetic fields. For example, beams of deuterons and tritons are injected in the same direction relative to the axis of a vacuum chamber. The ion beams are confined by the magnetic fields of long solenoids. The products of the fusion reactions, such as neutrons and alpha particles, escape to the wall surrounding the vacuum chamber, producing heat. The momentum of the deuterons is approximately equal to the momentum of the tritons, so that both types of ions follow the same path in the confining magnetic field. The velocity of the deuteron is sufficiently greater than the velocity of the triton so that overtaking collisions occur at a relative velocity which produces a high fusion reaction cross section. Electrons for space charge neutralization are obtained by ionization of residual gas in the vacuum chamber, and additionally from solid material (Irradiated with ultra-violet light or other energetic radiation) adjacent to the confinement region. For start-up operation, injected high-energy molecular ions can be dissociated by intense laser beam, producing trapping via change of charge state. When sufficiently intense deuteron and triton beams have been produced, the laser beam can be removed, and subsequent change of charge state can be achieved by collisions

  3. Inclusion and difusion studies of D in fusion breeding blanket candidate materials

    Energy Technology Data Exchange (ETDEWEB)

    Fan, L.

    2015-07-01

    Deuterium-Tritium (D-T) reaction is the most practical fusion reaction on the way to harness fusion energy. As tritium presents trace quantities on Earth [1], tritium fuel is essential to be generated simultaneously with the D-T reaction in a commerical fusion power plant. Tritium can be obtained in the lithium contained breeding blanket as a transmutation product of nuclear reaction 6Li (n, a)T. Li2T iO3 is considered to be one promising candidate solid tritium breeder material, due to its high lithium density, low activation, compatiblity with structure materials and high chemical stability. The tritium generated in Li2T iO3 breeding blanket needs to be collected and recycled back to the fusion reaction. Therefore, the study of the diffusion characteristic of breeder material Li2T iO3 is necessary to determine tritium mobility and tritium extraction efficiency. In order to study tritium release mechanism of Li2T iO3 breeding material in a fusion power plant environment, a fusion like neutron spectrum is essential while it is now not availble in any laboratory. One alternative is using ion accelerator or implantor to get energetic hydrogenic (H,D,T) ions impacting on breeding material, to simulate the tritium distribution situation. Because of the radioactive property of tritium which will complicate processing procedure, another isotope of hydrogen Deuterium is actually used to be studied. The defect structure in Li2T iO3, due to reactor exposure to fusion generated particles and ? ray irradiation, is achieved by energetic Ti ions. SRIM program is implemented to simulate the D ion or Ti ion distributions after bombarding, as well as the defects. X-ray diffraction technique helps to identify phase compositions. Transmission electron microscopy technique is used to observe the microstructures (Author)

  4. Quantum calculation of dipole excitation in fusion reaction

    International Nuclear Information System (INIS)

    Simenel, C.; Chomaz, Ph.; De France, G.

    2000-01-01

    The excitation of the giant dipole resonance by fusion is studied with N/Z asymmetry in the entrance channel. The TDHF solution exhibits a strong dipole vibration which can be associated with a giant vibration along the main axis of a fluctuating prolate shape. The consequences on the gamma-ray emission from hot compound nuclei are discussed. (author)

  5. Theory and Simulations of Incomplete Reconnection During Sawteeth Due to Diamagnetic Effects

    Science.gov (United States)

    Beidler, Matthew Thomas

    Tokamaks use magnetic fields to confine plasmas to achieve fusion; they are the leading approach proposed for the widespread production of fusion energy. The sawtooth crash in tokamaks limits the core temperature, adversely impacts confinement, and seeds disruptions. Adequate knowledge of the physics governing the sawtooth crash and a predictive capability of its ramifications has been elusive, including an understanding of incomplete reconnection, i.e., why sawteeth often cease prematurely before processing all available magnetic flux. In this dissertation, we introduce a model for incomplete reconnection in sawtooth crashes resulting from increasing diamagnetic effects in the nonlinear phase of magnetic reconnection. Physically, the reconnection inflow self-consistently convects the high pressure core of a tokamak toward the q=1 rational surface, thereby increasing the pressure gradient at the reconnection site. If the pressure gradient at the rational surface becomes large enough due to the self-consistent evolution, incomplete reconnection will occur due to diamagnetic effects becoming large enough to suppress reconnection. Predictions of this model are borne out in large-scale proof-of-principle two-fluid simulations of reconnection in a 2D slab geometry and are also consistent with data from the Mega Ampere Spherical Tokamak (MAST). Additionally, we present simulations from the 3D extended-MHD code M3D-C1 used to study the sawtooth crash in a 3D toroidal geometry for resistive-MHD and two-fluid models. This is the first study in a 3D tokamak geometry to show that the inclusion of two-fluid physics in the model equations is essential for recovering timescales more closely in line with experimental results compared to resistive-MHD and contrast the dynamics in the two models. We use a novel approach to sample the data in the plane of reconnection perpendicular to the (m,n)=(1,1) mode to carefully assess the reconnection physics. Using local measures of

  6. Nuclear fusion an energetic option to the future

    International Nuclear Information System (INIS)

    Medialdea Utande, A.; Sanchez Sanz, J.

    2007-01-01

    Nuclear fusion is the energy source of the Sun and the rest of starts. The great availability of deuterium on Earth, the inherent safety of the reactions involved and the intrinsic environmental respect make fusion an attractive energy source for the future of making of man king. International promising contributions are making Fusion Science and Technology progress by leaps and bounds to achieve its long term goal of cost-effective energy-producing plasmas. (Author)

  7. Cold nuclear fusion device

    International Nuclear Information System (INIS)

    Ogino, Shinji.

    1991-01-01

    Selection of cathode material is a key to the attainment of cold nuclear fusion. However, there are only few reports on the cathode material at present and an effective development has been demanded. The device comprises an anode and a cathode and an electrolytic bath having metal salts dissolved therein and containing heavy water in a glass container. The anode is made of gold or platinum and the cathode is made of metals of V, Sr, Y, Nb, Hf or Ta, and a voltage of 3-25V is applied by way of a DC power source between them. The metal comprising V, Sr, Y, Nb, Hf or Ta absorbs deuterium formed by electrolysis of heavy water effectively to cause nuclear fusion reaction at substantially the same frequency and energy efficiency as palladium and titanium. Accordingly, a cold nuclear fusion device having high nuclear fusion generation frequency can be obtained. (N.H.)

  8. Energy by nuclear fusion

    International Nuclear Information System (INIS)

    Buende, R.; Daenner, W.; Herold, H.; Raeder, J.

    1976-12-01

    This report reviews the state of knowledge in a number of fields of fusion research up to autumn 1976. Section 1 gives a very brief presentation of the elementary fusion reactions, the energies delivered by them and the most basic energy balances leading to Lawson-type diagrams. Section 2 outlines the reserves and cost of lithium and deuterium, gives estimates of the total energy available from DT fusion and comments on production technology, availlability and handling of the fuels. In section 3 a survey is given of the different concepts of magnetic confinement (stellarators, tokamaks, toroidal pinches, mirror machines, two-component plasmas), of confinement by walls, gas blankets and imploding liners and, finally, of the concepts of interial confinement (laser fusion, beam fusion). The reactors designed or outlined on the basis of the tokamak, high-β, mirror, and laser fusion concepts are presented in section 4, which is followed in section 5 by a discussion of the key problems of fusion power plants. The present-day knowledge of the cost structure of fusion power plants and the sensitivity of this structure with respect to the physical and technical assumptions made is analysed in section 6. Section 7 and 8 treat the aspects of safety and environment. The problems discussed include the hazard potentials of different designs (radiological, toxicological, and with respect to stored energies), release of radioactivity, possible kinds of malfunctioning, and the environmental impact of waste heat, radiation and radioactive waste (orig.) [de

  9. Nonthermal fusion reactor concept based on Hall-effect magnetohydrodynamics plasma theory

    International Nuclear Information System (INIS)

    Witalis, E.A.

    1988-01-01

    The failure of magnetic confinement controlled thermonuclear fusion research to achieve its goal is attributed to its foundation on the incomplete MHD plasma description instead of the more general HMHD (Hall-effect magnetohydrodynamics) theory. The latter allows for a certain magnetic plasma self-confinement under described stringent conditions. A reactor concept based on the formation, acceleration, and forced disintegration of magnetized whirl structures, plasmoids, is proposed. The four conventional MHD theory objections, i.e., absence of dynamo action, fast decay caused by resistivity, non-existence of magnetic self-confinement, and negligible non-thermal fusion yield, are shown not to apply. Support for the scheme from dense plasma focus research is pointed out. (orig.) [de

  10. Neutron dosimetry for radiation damage in fission and fusion reactors

    International Nuclear Information System (INIS)

    Smith, D.L.

    1979-01-01

    The properties of materials subjected to the intense neutron radiation fields characteristic of fission power reactors or proposed fusion energy devices is a field of extensive current research. These investigations seek important information relevant to the safety and economics of nuclear energy. In high-level radiation environments, neutron metrology is accomplished predominantly with passive techniques which require detailed knowledge about many nuclear reactions. The quality of neutron dosimetry has increased noticeably during the past decade owing to the availability of new data and evaluations for both integral and differential cross sections, better quantitative understanding of radioactive decay processes, improvements in radiation detection technology, and the development of reliable spectrum unfolding procedures. However, there are problems caused by the persistence of serious integral-differential discrepancies for several important reactions. There is a need to further develop the data base for exothermic and low-threshold reactions needed in thermal and fast-fission dosimetry, and for high-threshold reactions needed in fusion-energy dosimetry. The unsatisfied data requirements for fission reactor dosimetry appear to be relatively modest and well defined, while the needs for fusion are extensive and less well defined because of the immature state of fusion technology. These various data requirements are examined with the goal of providing suggestions for continued dosimetry-related nuclear data research

  11. Potential surfaces in symmetric heavy-ion reactions

    International Nuclear Information System (INIS)

    Royer, G.; Piller, C.; Mignen, J.; Raffray, Y.

    1989-01-01

    The entrance channel in symmetric heavy-ion reactions is studied in the liquid-drop model approach including the nuclear proximity energy and allowing ellipsoidal deformations of the colliding nuclei. In the whole mass range a sudden transition occurs from oblate to prolate shapes when the proximity forces become important. This strongly affects the effective moment of inertia. The ellipsoidal deformations reduce the fusion barrier width for light systems and lower the potential barrier height for medium and heavy nuclei. The results are in agreement with the empirical effective barrier shift determined by Aguiar et al for the 58 Ni + 58 Ni, 74 Ge + 74 Ge and 80 Se + 80 Se systems. The sub-barrier fusion enhancement in heavy-ion reactions might be explained by the slowness of the process. Below the static fusion barrier, the reaction time is long; allowing some adiabaticity and deformations of the colliding ions. Above the barrier, the reaction is more sudden and the deformation degree of freedom is frozen

  12. A Markov game theoretic data fusion approach for cyber situational awareness

    Science.gov (United States)

    Shen, Dan; Chen, Genshe; Cruz, Jose B., Jr.; Haynes, Leonard; Kruger, Martin; Blasch, Erik

    2007-04-01

    This paper proposes an innovative data-fusion/ data-mining game theoretic situation awareness and impact assessment approach for cyber network defense. Alerts generated by Intrusion Detection Sensors (IDSs) or Intrusion Prevention Sensors (IPSs) are fed into the data refinement (Level 0) and object assessment (L1) data fusion components. High-level situation/threat assessment (L2/L3) data fusion based on Markov game model and Hierarchical Entity Aggregation (HEA) are proposed to refine the primitive prediction generated by adaptive feature/pattern recognition and capture new unknown features. A Markov (Stochastic) game method is used to estimate the belief of each possible cyber attack pattern. Game theory captures the nature of cyber conflicts: determination of the attacking-force strategies is tightly coupled to determination of the defense-force strategies and vice versa. Also, Markov game theory deals with uncertainty and incompleteness of available information. A software tool is developed to demonstrate the performance of the high level information fusion for cyber network defense situation and a simulation example shows the enhanced understating of cyber-network defense.

  13. Complex fragment emission at low and high excitation energy

    International Nuclear Information System (INIS)

    Moretto, L.G.

    1986-08-01

    Complex fragment emission has been certified as a compound nucleus process at low energies. An extension of the measurements to heavy ion reactions up to 50 MeV/u shows that most complex fragments are emitted by highly excited compound nuclei formed in incomplete fusion reactions. 12 refs., 26 figs

  14. An accelerated beam-plasma neutron/proton source and early application of a fusion plasma

    International Nuclear Information System (INIS)

    Ohnishi, M.; Yoshikawa, K.; Yamamoto, Y.; Hoshino, C.; Masuda, K.; Miley, G.; Jurczyk, B.; Stubbers, R.; Gu, Y.

    1999-01-01

    We measured the number of the neutrons and protons produced by D-D reactions in an accelerated beam-plasma fusion and curried out the numerical simulations. The linear dependence of the neutron yield on a discharge current indicates that the fusion reactions occur between the background gas and the fast particles. i.e. charge exchanged neutrals and accelerated ions. The neutron yield divided by (fusion cross section x ion current x neutral gas pressure) still possesses the dependence of the 1.2 power of discharge voltage. which shows the fusion reactions are affected by the electrostatic potential built-up in the center. The measured proton birth profiles suggest the existence of a double potential well, which is supported by the numerical simulations. (author)

  15. Failure rate data for fusion safety and risk assessment

    International Nuclear Information System (INIS)

    Cadwallader, L.C.

    1993-01-01

    The Fusion Safety Program (FSP) at the Idaho National Engineering Laboratory (INEL) conducts safety research in materials, chemical reactions, safety analysis, risk assessment, and in component research and development to support existing magnetic fusion experiments and also to promote safety in the design of future experiments. One of the areas of safety research is applying probabilistic risk assessment (PRA) methods to fusion experiments. To apply PRA, we need a fusion-relevant radiological dose code and a component failure rate data base. This paper describes the FSP effort to develop a failure rate data base for fusion-specific components

  16. The Role of Incompleteness in Commodity Futures Markets

    Directory of Open Access Journals (Sweden)

    Takashi eKanamura

    2015-10-01

    Full Text Available This paper proposes a convenience yield-based pricing for commodity futures, which embeds incompleteness of commodity futures markets in convenience yields. By using the pricing method, we conduct empirical analyses of the prices of WTI crude oil, heating oil, and natural gas futures traded on the NYMEX in order to assess the incompleteness of energy futures markets. We show that the fluctuation from the incompleteness is partly driven by the fluctuation from convenience yields. In addition, it is shown that the incompleteness of natural gas futures market is more highlighted than the incompleteness of WTI crude oil and heating oil futures markets. We apply the implied market price of risk from the NYMEX data to pricing an Asian call option written on WTI crude oil futures. Finally, we try to apply the market incompleteness analysis to the post-crisis periods after 2009.

  17. Disintegration of nuclei and formation of composite systems in intermediate energy heavy ion reactions

    International Nuclear Information System (INIS)

    Gregoire, C.; Jacquet, D.; Sebille, F.; Vinet, L.; Pi, M.; Suraud, E.; Schuck, P.

    1987-04-01

    In a first part, the Landau-Vlasov dynamical instabilities found in the expansion of an excited nucleus are discussed with their dependence on the initial preparation. In a second part, we show the absence of fusion window when residual interactions are involved. We describe also onset and properties of ineffectual and incomplete fusion for systems like 40 Ar + 27 Al and 238 U near the Fermi energy and 12 C + 139 La at 50 MeV/u

  18. Influence of Incomplete Mixing on the OH-Isoprene Reaction in the Lower Troposphere - Measurements Above the Amazon Rain Forest and General Considerations

    Science.gov (United States)

    Sörgel, M.; Dlugi, R. J. W.; Berger, M.; Mallik, C.; Tsokankunku, A.; Zelger, M.; Acevedo, O. C.; Dias, N. L.; Hofzumahaus, A.; Kesselmeier, J.; Kramm, G.; Marno, D. R.; Martinez, M.; Nölscher, A.; H G, O.; Pfannerstill, E.; Bourtsoukidis, E.; Rohrer, F.; Tauer, S.; Williams, J.; Yanez Serrano, A. M.; Andreae, M. O.; Harder, H.

    2017-12-01

    Incomplete mixing of reactants in the atmosphere (segregation) causes reduced reaction rates compared to laboratory values derived for well mixed conditions. To adequately determine the actual reaction rates in a variety of natural environments where the distribution of sources and sinks leads to inhomogeneous distribution of reactants, the intensity of segregation (IS) has to be taken into account. Although, there has been considerable progress in modeling IS in the boundary layer within the last 30 years, calculations from direct observations are still sparse as high time resolution and time synchronization are required. OH-radicals are the most important oxidizing agent in the atmosphere, and are therefore regarded as the detergent of the atmosphere, reacting with the majority of atmospheric pollutants and therefore accelerating their removal from the atmosphere. Hence, to understand atmospheric self-cleansing, we need to quantify and understand the budgets (sources and sinks) of OH. As it is a fast reacting compound, for some of its reactants mixing will limit the reaction rate. The reaction of isoprene and OH radicals has gained considerable interest in recent years since large discrepancies between modeled and measured OH have been found mainly in high isoprene environments. This motivated not only laboratory studies on unknown recycling mechanisms for OH in this reaction, but also modeling work and field studies on the effect of segregation on this reaction. We measured OH radicals, isoprene and other species that are either precursors of OH or promote OH recycling (e.g. O3, NOx, HO2, H2O) with high time resolution (1-10 Hz) closely above a rain forest canopy (at 41 m above ground level) at the ATTO (Amazon Tall Tower Observatory) site (02°08'38.8''S, 58°59'59.5''W). The site is characterized by high isoprene (up to 20 ppb) and low NO (50 -500 ppt). Simultaneous measurements of OH and isoprene with high time resolution so far have been sparse. To our

  19. Applications of solid-state nuclear track detectors (SSNTDs) for fast ion and fusion reaction product measurements in TEXTOR experiments

    Energy Technology Data Exchange (ETDEWEB)

    Szydlowski, A.; Malinowski, K.; Malinowska, A. [Association EURTOM-IPPLM Warsaw, The Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Wassenhove, G. Van [EURATOM-Belgium State Association, LPP, ERM/KMS, Trilateral Euregio Cluster, B-1000 Brussels (Belgium); Schweer, B. [Association EURATOM-FZJ, Institutte of Plasma Physicx, Juelich (Germany)

    2011-07-01

    Full text of publication follows: The paper reports on measurements of fusion reaction protons which were performed on TEXTOR facility in January 2009. The basic experimental scheme was similar to that applied in the previous measurements [1, 2]. The main experimental tool equipment was a small ion pinhole camera which was equipped with a PM-355 detector sample and was attached to a water cooled manipulator. The camera was placed below the plasma ring in the direction of ion drifts, at a distance of 4.4 cm from LCFS. However, in the described experiment it was aligned at an angle to the mayor TEXTOR radius (contrary to previous experiments), so that the input pinhole was oriented first at {gamma} = 45 degrees (shots 108799 - 108818) and then {gamma} = 600 (shots 108832 - 108847). The discharges were executed with one neutral beam of the total power 0.6 - 1.0 MW. In the first series (Nos 108799 - 108818) the plasma was additionally heated by ICRH of frequency 38 MHz. The irradiated detector samples were subjected to the same interrupted etching procedure as the samples used in the CR-39/PM-355 detector calibration measurements [1, 2]. After that, track density distributions and track diameter histograms were measured under an optical microscope. By the use of the calibration curves, it was possible to distinguish craters produced by protons from other craters and to convert the obtained histograms into proton energy spectra. The craters induced by lower energy ions appeared to be concentrated in narrower areas, whereas higher energy ions were registered in a more diffused detector fields. The paper shows again that the CR-39/PM-355 detector is an useful diagnostic tool for tokamak experiments, for measurement of charged ions. References: [1] A. Szydlowski, A. Malinowska, M. Jaskola, A. Korman, M.J. Sadowski, G. Van Wassenhove, B. Schweer and the TEXTOR team, A. Galkowski, 'Application of Solid State Nuclear Track Detectors in TEXTOR Experiment for Measurements

  20. Fusion-fission dynamics and perspectives of future experiments

    International Nuclear Information System (INIS)

    Zagrebaev, V.I.; Itkis, M.G.; Oganessian, Yu.Ts.

    2003-01-01

    The paper is focused on reaction dynamics of superheavy-nucleus formation and decay at beam energies near the Coulomb barrier. The aim is to review the things we have learned from recent experiments on fusion-fission reactions leading to the formation of compound nuclei with Z ≥ 102 and from their extensive theoretical analysis. Major attention is paid to the dynamics of formation of very heavy compound nuclei taking place in strong competition with the process of fast fission (quasifission). The choice of collective degrees of freedom playing a fundamental role and finding the multidimensional driving potential and the corresponding dynamic equation regulating the whole process are discussed. A possibility of deriving the fission barriers of superheavy nuclei directly from performed experiments is of particular interest here. In conclusion, the results of a detailed theoretical analysis of available experimental data on the 'cold' and 'hot' fusion-fission reactions are presented. Perspectives of future experiments are discussed along with additional theoretical studies in this field needed for deeper understanding of the fusion-fission processes of very heavy nuclear systems

  1. Microscopic observations of palladium used for cold fusion

    International Nuclear Information System (INIS)

    Matsumoto, T.

    1991-01-01

    This paper examines the microscopic structures of palladium metals used for cold fusion experiments. Tiny spot defects suggesting cold fusion have been observed in grain boundaries as the Nattoh model predicts. The relationship between these defects and a series of neutron busts and an indirect loop of hydrogen chain reactions are discussed

  2. Fusion energy for the 21st century

    International Nuclear Information System (INIS)

    Harris, J.H.

    1999-01-01

    Fusion reactions like those that power the stars have the potential of providing bulk electricity generation with reduced emissions and low radioactive hazard, but pose many challenges in physics and technology. The H-1 Heliac Major National Research Facility now being developed offers Australian scientists and engineers an opportunity to participate in the collaborative international fusion research program. Work on H-1NF contributes not only to the realisation of fusion power, but offers the stimulus and opportunity for advanced training and the development of spin-off technology

  3. ROK-PRC Cooperation on Laser Fusion Energy

    International Nuclear Information System (INIS)

    Rhee, Yong Joo; Han, J. M.; Lee, S. M.; Nam, S. M.; Kwan, D. H.; Cha, Y. H.; Baek, S. H.

    2009-03-01

    International treaties on the reduction of green-house gases are now being established worldwide and Korea is supposed to join these treaties in a near future. Meanwhile the energy production via fission reactors proposed as a solution to this global environmental contamination has still inherent problems in that it also produces long-life radioactive nuclear waste in the long run, causing many serious social issues. Now the ultimate solution in this situation is believed to be the production of energy by the nuclear fusion reaction. In this project, the collaboration regarding high energy laser fusion has been carried out mainly at the Chinese facility such as ShengGuang II (SG II) laser facility, and ultrahigh intensity laser system of KAERI has been used for the small scale laser fusion and production of fast neutrons. Thomson scattering experiment to analyze the fusion plasma, opacity measurement to understand and develop the computer simulation techniques have been carried out at SG II facility, and experiments on implosion reaction which is basic to laser fusion as well as that of X-ray absorption and transmission have been done at the GEKKO XII facility of ILE, Japan. Satisfactory results both for Korea and China have been deduced by the strategy of project such that different approaches for high energy laser fusion and low energy laser fusion were applied. That is, Korean partner could get opportunities of doing experiments at the large laser facilities to get plasma diagnostic technologies and high density simulation technologies, besides the opportunity to participate in the K-C-J collaborative experiments of implosion and X-ray spectroscopy. And Chinese partner could solve their problem related to the laser fusion and neutron generation which were not successful even with their far high 300TW laser system

  4. Unexpected heterogeneity of BCR-ABL fusion mRNA detected by polymerase chain reaction in Philadelphia chromosome-positive acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Hooberman, A.L.; Carrino, J.J.; Leibowitz, D.; Rowley, J.D.; Le Beau, M.M.; Arlin, Z.A.; Westbrook, C.A.

    1989-01-01

    The Philadelphia (Ph 1 ) chromosome results in a fusion of portions of the BCR gene from chromosome 22 and the ABL gene from chromosome 9, producing a chimeric BCR-ABL mRNA and protein. In lymphoblastic leukemias, there are two molecular subtypes of the Ph 1 chromosome, one with a rearrangement of the breakpoint cluster region (bcr) of the BCR gene, producing the same 8.5-kilobase BCR-ABL fusion mRNA seen in chronic myelogenous leukemia (CML), and the other, without a bcr rearrangement, producing a 7.0-kilobase BCR-ABL fusion mRNA that is seen only in acute lymphoblastic leukemia (ALL). The authors studied the molecular subtype of the Ph 1 chromosome in 11 cases of Ph 1 -positive ALL, including 2 with a previous diagnosis of CML, using a sensitive method to analyze the mRNA species based on the polymerase chain reaction (PCR). They observed unexpected heterogeneity in BCR-ABL mRNA in this population. They conclude that the PCR gives additional information about the Ph 1 chromosome gene products that cannot be obtained by genomic analysis, but that it cannot be used as the sole means of detection of this chromosomal abnormality in ALL because of the high incidence of false negative results

  5. Study of charged fusion products in laser produced plasmas

    International Nuclear Information System (INIS)

    Rosenblum, M.

    1981-07-01

    Charged reaction products play a central role in inertial confinement fusion. The investigation of the various processes these particles undergo in laser produced plasmas, their influence on the dynamics of the fusion and their utilization as a diagnostic tool are the main subjects of this thesis. (author)

  6. Investigation of fractional momentum transfer: measurement of forward recoil ranges in 16O + natTm collisions

    International Nuclear Information System (INIS)

    Singh, Pushpendra P.; Unnati; Sharma, Manoj Kumar; Singh, B.P.; Prasad, R.; Rakesh Kumar; Golda, K.S.; Bhardwaj, H.D.

    2006-01-01

    For better understanding of complete fusion and incomplete fusion in heavy ion reactions a programme of precise measurements of excitation functions, recoil range distribution and angular distributions of recoils has been undertaken. In the present contribution the recoil range distribution for the residues have been measured at ≅ 6 MeV/nucleon, using recoil-catcher technique followed by off-line gamma-spectroscopy

  7. Programmable fusion of liposomes mediated by lipidated PNA

    DEFF Research Database (Denmark)

    Rabe, A; Löffler, P M G; Ries, O

    2017-01-01

    We recently reported a DNA-programmed fusion cascade enabling the use of liposomes as nanoreactors for compartmentalized chemical reactions. This communication reports an alternative and robust strategy based on lipidated peptide nucleic acids (LiPs). LiPs enabled fusion of liposomes with remarka...... with remarkable 31% efficiency at 50 °C with low leakage (5%)....

  8. Fusion17 summary talk: windsurfing on a cross section profile

    Directory of Open Access Journals (Sweden)

    Ackermann Dieter

    2017-01-01

    Full Text Available The spectrum of physics, discussed in the 7th edition of the “Fusion” conference series, included a number of topics, ranging from reaction dynamics to structure studies, from the lightest to the heaviest nuclei, from inelastic reactions to fusion and fission, with applications of astrophysical interest and the newest developments and findings in theory and experiment. With this paper we try to summarize the most relevant issues discussed during the five days of Fusion17.

  9. Prospects for developing attractive inertial fusion concepts

    International Nuclear Information System (INIS)

    Cornwall, T.; Bodner, S.; Herrmannsfeldt, W.B.; Hogan, W.; Storm, E.; VanDevender, J.P.

    1986-01-01

    The authors discuss the role of inertial fusion in relationship to defense activities as well as in relation to energy alternatives. Other general advantages to inertial fusion besides maintaining the system more cheaply and easily, are discussed such as certain designs and the use of very short wavelength with a very modest laser intensity. A discussion on the direct illumination approach is offered. The progress made in high-gain target physics and the potential for development of solid-state lasers as a potential multimegajoule driver and a potential high-rep-rate fusion driver are discussed. Designs for reaction chambers are examined, as is the heavy-ion fusion program. Light-ion accelerators are also discussed

  10. Fusion Safety Program annual report, fiscal year 1992

    International Nuclear Information System (INIS)

    Holland, D.F.; Cadwallader, L.C.; Herring, J.S.; Longhurst, G.R.; McCarthy, K.A.; Merrill, B.J.; Piet, S.J.

    1993-01-01

    This report summarizes the major activities of the Fusion Safety Program in fiscal year 1992. The Idaho National Engineering Laboratory (INEL) is the designated lead laboratory and EG ampersand G Idaho, Inc. is the prime contractor for this program. The Fusion Safety Program was initiated in 1979. Activities are conducted at the INEL and in participating organizations including the Westinghouse Hanford Company at the Hanford Engineering Development Laboratory, the Massachusetts Institute of Technology, and the University of Wisconsin. The technical areas covered in the report include tritium safety, activation product release, reactions involving beryllium, reactions involving lithium breeding materials, safety of fusion magnet systems, plasma disruptions, risk assessment failure rate data base, and computer code development for reactor transients. Also included in the report is a summary of the safety and environmental studies performed by the INEL for the Tokamak Physics Experiments and the Tokamak Fusion Test Reactor, the safety analysis for the International Thermonuclear Experimental Reactor design, and the technical support for the ARIES commercial reactor design study

  11. Controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Trocheris, M.

    1975-01-01

    An outline is given of the present position of research into controlled fusion. After a brief reminder of the nuclear reactions of fusion and the principle of their use as a source of energy, the results obtained by the method of magnetic confinement are summarized. Among the many solutions that have been imagined and tried out to achieve a magnetic containing vessel capable of holding the thermonuclear plasma, the devices of the Tokamak type have a good lead and that is why they are described in greater detail. An idea is then given of the problems that arise when one intends conceiving the thermonuclear reactor based on the principle of the Tokamaks. The last section deals with fusion by lasers which is a new and most attractive alternative, at least from the viewpoint of basis physics. The report concludes with an indication of the stages to be passed through to reach production of energy on an industrial scale [fr

  12. The Role of the JET Project in Global Fusion Research

    DEFF Research Database (Denmark)

    Jensen, Vagn Orla

    1983-01-01

    The aim of nuclear fusion research is to make fusion energy available as a new energy source. Fusion processes occur naturally in the sun, where hydrogen nuclei release energy by combining to form helium. A fusion reactor on earth will require even higher temperatures than in the interior...... of the sun, and it will be based on deuterium and tritium reactions. JET (Joint European Torus) is a major fusion experiment now under construction near Abingdon in the UK It is aimed at producing conditions approximating those necessary in a fusion reactor. The results expected from JET should permit...... a realistic evaluation of the prospects for fusion power and serve as a basis for the design of the next major fusion experiment....

  13. Light particle emission in light heavy-ion induced reactions

    International Nuclear Information System (INIS)

    Bozek, E.; Cassagnou, Y.; Dayras, R.

    1982-01-01

    A detailed study was made of the different processes which may compete with fusion in the energy domain where the cross section for fusion deviates from the reaction cross section. Both reactions 14 N + 12 C and 16 O + 10 B were used to form the compound nucleus 26 Al at the same excitation energy of 44 MeV

  14. Single-flux-quantum logic circuits exploiting collision-based fusion gates

    International Nuclear Information System (INIS)

    Asai, T.; Yamada, K.; Amemiya, Y.

    2008-01-01

    We propose a single-flux-quantum (SFQ) logic circuit based on the fusion computing systems--collision-based and reaction-diffusion fusion computers. A fusion computing system consists of regularly arrayed unit cells (fusion gates), where each unit has two input arms and two output arms and is connected to its neighboring cells with the arms. We designed functional SFQ circuits that implemented the fusion computation. The unit cell was able to be made with ten Josephson junctions. Circuit simulation with standard Nb/Al-AlOx/Nb 2.5-kA/cm 2 process parameters showed that the SFQ fusion computing systems could operate at 10 GHz clock

  15. Fusion probability and survivability in estimates of heaviest nuclei production

    Directory of Open Access Journals (Sweden)

    Sagaidak Roman N.

    2012-02-01

    Full Text Available Production of the heavy and heaviest nuclei (from Po to the region of superheavy elements close to Z=114 and N=184 in fusion-evaporation reactions induced by heavy ions has been considered in a systematic way within the framework of the barrier-passing model coupled with the statistical model (SM of de-excitation of a compound nucleus (CN. Excitation functions for fission and evaporation residues (ER measured in very asymmetric combinations can be described rather well. One can scale and fix macroscopic (liquid-drop fission barriers for nuclei involved in the calculation of survivability with SM. In less asymmetric combinations, effects of fusion suppression caused by quasi-fission (QF are starting to appear in the entrance channel of reactions. QF effects could be semi-empirically taken into account using fusion probabilities deduced as the ratio of measured ER cross sections to the ones obtained in the assumption of absence of the fusion suppression in corresponding reactions. SM parameters (fission barriers obtained at the analysis of a very asymmetric combination leading to the production of (nearly the same CN should be used for this evaluation.

  16. Liquid-drop effects in sub-barrier fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, C E; Barbosa, V C; Canto, L F; Donangelo, R

    1988-01-28

    We introduce an operational measure for the enhancement of the fusion cross section at sub-barrier energies in terms of an asymptotic energy shift ..delta..E. It is shown that ..delta..E has a continuously growing trend with the size of the system. This trend is explained in terms of neck formation using the liquid-drop model. Deviations from this trend are attributed to strong coupling to specific channels.

  17. Studies of 4He emission in both fusion-like and inelastic reactions of 340-MeV 40Ar + 238U

    International Nuclear Information System (INIS)

    Kildir, M.; Logan, D.; Kaplan, M.; Zisman, M.S.; Guerreau, D.; Alexander, J.M.; Vaz, L.C.

    1982-01-01

    The fission-fragment angular correlation technique has been used in conjunction with a position-sensitive avalanche detector to identify the fusion-like and inelastic collisions of 340-MeV 40 Ar + 238 U. For each of these two reaction types, we have characterized the correlated 4 He emission by measuring three-fold coincidences between two fission fragments and the light charged particle. We find an abundance of both evaporation-like and direct 4 He emission, each of which is associated with both fusion-fission and sequential-fission processes. Several comparison tests of both the coincidence and singles data strongly indicate that very little 4 He emission is due to evaporation from accelerated fission fragments in this system. The evaporative 4 He emission appears instead to have a strong contribution originating from the composite system prior to fission. The forward angle 4 He emissions, characterized by prominent forward-peaking and relatively high energies, suggest an origin associated with the very early stages of the collision

  18. Fusion Materials Irradiation Test Facility: a facility for fusion-materials qualification

    International Nuclear Information System (INIS)

    Trego, A.L.; Hagan, J.W.; Opperman, E.K.; Burke, R.J.

    1983-01-01

    The Fusion Materials Irradiation Test Facility will provide a unique testing environment for irradiation of structural and special purpose materials in support of fusion power systems. The neutron source will be produced by a deuteron-lithium stripping reaction to generate high energy neutrons to ensure damage similar to that of a deuterium-tritium neutron spectrum. The facility design is now ready for the start of construction and much of the supporting lithium system research has been completed. Major testing of key low energy end components of the accelerator is about to commence. The facility, its testing role, and the status and major aspects of its design and supporting system development are described

  19. Controlled nuclear fusion apparatus

    International Nuclear Information System (INIS)

    Bussard, R.W.; Coppi, B.

    1982-01-01

    A fusion power generating device is disclosed having a relatively small and inexpensive core region which may be contained within an energy absorbing blanket region. The fusion power core region contains apparatus of the toroidal type for confining a high density plasma. The fusion power core is removable from the blanket region and may be disposed and/or recycled for subsequent use within the same blanket region. Thermonuclear ignition of the plasma is obtained by feeding neutral fusible gas into the plasma in a controlled manner such that charged particle heating produced by the fusion reaction is utilized to bootstrap the device to a region of high temperatures and high densities wherein charged particle heating is sufficient to overcome radiation and thermal conductivity losses. The high density plasma produces a large radiation and particle flux on the first wall of the plasma core region thereby necessitating replacement of the core from the blanket region from time to time. A series of potentially disposable and replaceable central core regions are disclosed for a large-scale economical electrical power generating plant

  20. What can we learn about heavy ion fusion by studying fission angular distributions

    International Nuclear Information System (INIS)

    Back, B.B.

    1984-01-01

    Determinations of complete fusion reactions leading to fissionable systems are associated with problems of separating fragments from quasi-fission reactions from those arising from fission of the completely fused system. Inferring complete fusion cross sections from the minute cross sections for the evaporation residue channel is hampered by the insufficient knowledge of the branching ratio for neutron emission and fission in the decay sequence of the completely fused system. From a quantitative analysis of the fragment angular distributions it is, however, possible under certain assumptions to deduce the relative contribution of complete fusion and quasi-fission. It is found that the complete fusion process is hindered for heavy projectiles. The excess radial energy over the interaction barrier needed to induce fusion with heavy projectiles is determined in several cases and systematic trends are presented

  1. Cluster expression in fission and fusion in high-dimensional macroscopic-microscopic calculations

    International Nuclear Information System (INIS)

    Iwamoto, Akira; Ichikawa, Takatoshi; Moller, Peter; Sierk, Arnold J.

    2004-01-01

    We discuss the relation between the fission-fusion potential-energy surfaces of very heavy nuclei and the formation process of these nuclei in cold-fusion reactions. In the potential-energy surfaces, we find a pronounced valley structure, with one valley corresponding to the cold-fusion reaction, the other to fission. As the touching point is approached in the cold-fusion entrance channel, an instability towards dynamical deformation of the projectile occurs, which enhances the fusion cross section. These two 'cluster effects' enhance the production of superheavy nuclei in cold-fusion reactions, in addition to the effect of the low compound-system excitation energy in these reactions. Heavy-ion fusion reactions have been used extensively to synthesize heavy elements beyond actinide nuclei. In order to proceed further in this direction, we need to understand the formation process more precisely, not just the decay process. The dynamics of the formation process are considerably more complex than the dynamics necessary to interpret the spontaneous-fission decay of heavy elements. However, before implementing a full dynamical description it is useful to understand the basic properties of the potential-energy landscape encountered in the initial stages of the collision. The collision process and entrance-channel landscape can conveniently be separated into two parts, namely the early-stage separated system before touching and the late-stage composite system after touching. The transition between these two stages is particularly important, but not very well understood until now. To understand better the transition between the two stages we analyze here in detail the potential energy landscape or 'collision surface' of the system both outside and inside the touching configuration of the target and projectile. In Sec. 2, we discuss calculated five-dimensional potential-energy landscapes inside touching and identify major features. In Sec. 3, we present calculated

  2. International fusion research

    International Nuclear Information System (INIS)

    Pease, R.S.

    1983-01-01

    Nuclear energy of the light elements deuterium and lithium can be released if the 100 MK degree temperature required for deuterium-tritium thermonuclear fusion reactions can be achieved together with sufficient thermal insulation for a net energy yield. Progress of world-wide research shows good prospect for these physical conditions being achieved by the use of magnetic field confinement and of rapidly developing heating methods. Tokamak systems, alternative magnetic systems and inertial confinement progress are described. International co-operation features a number of bilateral agreements between countries: the Euratom collaboration which includes the Joint European Torus, a joint undertaking of eleven Western European nations of Euratom, established to build and operate a major confinement experiment; the development of co-operative projects within the OECD/IEA framework; the INTOR workshop, a world-wide study under IAEA auspices of the next major step in fusion research which might be built co-operatively; and assessments of the potential of nuclear fusion by the IAEA and the International Fusion Research Council. The INTOR (International Tokamak Reactor) studies have outlined a major plant of the tokamak type to study the engineering and technology of fusion reactor systems, which might be constructed on a world-wide basis to tackle and share the investment risks of the developments which lie ahead. This paper summarizes the recent progress of research on controlled nuclear fusion, featuring those areas where international co-operation has played an important part, and describes the various arrangements by which this international co-operation is facilitated. (author)

  3. Stochastic incompleteness of quantum mechanics

    International Nuclear Information System (INIS)

    Suppes, P.; Zanotti, M.

    1976-01-01

    This article brings out in as conceptually clear terms as possible what seems to be a major incompleteness in the probability theory of particles offered by classical quantum mechanics. The exact nature of this incompleteness is illustrated by consideration of some simple quantum-mechanical examples. In addition, these examples are contrasted with the fundamental assumptions of Brownian motion in classical physics on the one hand, and with a controversey of a deecade ago in mathematical physchology. The central claim is that clasical quantum mechanics is radically incomplete in its probabilistic account of the motion of particles. In the last part of the article the time-dependent joint distribution of position and momentum of the linear harmonic oscillator is derived, and it is shown how the apparently physically paradoxical statistical independence of position and momentum has a natural explanation. The explanation is given within the framework of the non-quantum-mechanical stochastic theory constructed for such oscillators. (Auth.)

  4. Heavy ion beam propagation through a gas-filled chamber for inertial confinement fusion

    International Nuclear Information System (INIS)

    Barboza, N.O.

    1996-10-01

    The work presented here evaluates the dynamics of a beam of heavy ions propagating through a chamber filled with gas. The motivation for this research stems from the possibility of using heavy ion beams as a driver in inertial confinement fusion reactors for the purpose of generating electricity. Such a study is important in determining the constraints on the beam which limit its focus to the small radius necessary for the ignition of thermonuclear microexplosions which are the source of fusion energy. Nuclear fusion is the process of combining light nuclei to form heavier ones. One possible fusion reaction combines two isotopes of hydrogen, deuterium and tritium, to form an alpha particle and a neutron, with an accompanying release of ∼17.6 MeV of energy. Generating electricity from fusion requires that we create such reactions in an efficient and controlled fashion, and harness the resulting energy. In the inertial confinement fusion (ICF) approach to energy production, a small spherical target, a few millimeters in radius, of deuterium and tritium fuel is compressed so that the density and temperature of the fuel are high enough, ∼200 g/cm 3 and ∼20 keV, that a substantial number of fusion reactions occur; the pellet microexplosion typically releases ∼350 MJ of energy in optimized power plant scenarios

  5. Study of the peripheral projectile-like fragments from the reaction 129Xe on 27Al, natCu, 139La and 165Ho, at E/A = 50 MeV

    International Nuclear Information System (INIS)

    Garcia-Solis, E.J.; Russ, D.E.; Madani, H.

    1996-01-01

    There are several reaction mechanisms identified for peripheral heavy-ion collisions. For low bombarding energies (E/A ∼ 10 MeV) the predominant reaction channel is the deep-inelastic reaction mechanism. In this process, the projectile and target form a rotating binary system, interchanging nucleons and angular momentum until they separate. At higher bombarding energies (E/A ∼ 50 to 100 MeV) incomplete fusion is thought to be the prevailing reaction channel. In this type of interaction part of the projectile merges with the target during the collision. Finally, for energies greater than 100 MeV/A, the main reaction channel is characterized by the formation of a highly-excited separate fragment (fireball) produced during the overlap between the projectile and the target. The data set studied was from an experiment designed to characterize the projectile-like products of the 27 Al, nat Cu, 139 La, and 165 Ho reactions at E/A = 50 MeV, which was performed at the Michigan State University Super Cyclotron Laboratory (MSU-NSCL). The Maryland Forward Array (MFA), was used to measure projectile-like fragments in coincidence with target-like fragments and light-charge particles in the MSU 4π detector

  6. The mechanical consequence of failure of ossified union in attempted posterior spinal fusion. A canine model.

    Science.gov (United States)

    Stonecipher, T K; Vanderby, R; Sciammarella, C A; Lei, S S; Fisk, J R

    1983-01-01

    The mechanical behavior of pseudarthrosis in posterior spinal fusion was investigated. A canine model was developed in which an incompletely ossified posterior fusion mass was consistently produced. The spines were excised, and the motion segments were mechanically tested using a specially developed loading apparatus. Tests were performed to evaluate stiffness of the segments to loading with compression, torsion, and anterioposterior and lateral bending shear stiffness. Changes in other modes of loading were less consistent. The motion characteristics of the pseudarthrosis could not be predicted from the extent of the osseous defect noted on roentgenograms. These findings correlate clinically with the progression of curvature seen with pseudarthrosis in scoliosis surgery and the unpredictable results of pseudarthrosis in posterior fusion performed in treatment of degenerative disc disease.

  7. Synthesis of superheavy elements by cold fusion

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S [Gesellschaft fuer Schwerionenforschung (GSI), Helmholtzzentrum fuer Schwerionenforschung Gmbh (Germany)

    2009-12-31

    The nuclear shell model predicts that the next doubly magic shell-closure beyond {sup 208}Pb is at the proton number Z=114, 120, or 126 and at the neutron number N=172 or 184. The outstanding aim of experimental investigations is the exploration of this region of spherical 'Super Heavy Elements' (SHEs). Using cold fusion reactions which are based on lead and bismuth targets, the new elements from 107 to 112 were synthesized at GSI in Darmstadt, Germany. Some of these results were confirmed at RIKEN in Wako, Japan, where also a relatively neutron-deficient isotope of element 113 was synthesized. In hot fusion reactions of {sup 48}Ca projectiles with actinide targets, a more neutron-rich isotope of element 112 and the new elements from 113 to 116 and even 118 were produced at FLNR in Dubna, Russia. Recently, part of these hot fusion data, which represent the first identification of nuclei located on the predicted island of SHEs, were confirmed in two independent experiments. The decay data reveal that for the heaviest elements, the dominant decay mode is alpha emission rather than fission. The decay properties as well as reaction cross-sections are compared with results of theoretical studies.

  8. Metal Catalyzed Fusion: Nuclear Active Environment vs. Process

    Science.gov (United States)

    Chubb, Talbot

    2009-03-01

    To achieve radiationless dd fusion and/or other LENR reactions via chemistry: some focus on environment of interior or altered near-surface volume of bulk metal; some on environment inside metal nanocrystals or on their surface; some on the interface between nanometal crystals and ionic crystals; some on a momentum shock-stimulation reaction process. Experiment says there is also a spontaneous reaction process.

  9. Experimental Determination of the Possible Deuterium - Deuterium Fusion Reaction Originated in a Single Cavitation Bubble Luminescence System Using CDCL3 and D2 O

    International Nuclear Information System (INIS)

    Barbaglia, Mario; Florido, Pablo; Mayer, Roberto; Bonetto, Fabian

    2003-01-01

    We focus this work on the measurement of the possible Deuterium - Deuterium reaction in a SCBL (Single Cavitation Bubble Luminescence) system.We measure the possible reaction at the bubble generation time and at the bubble collapse time. We use a Nd:YAG laser and CDCl 3 and D 2 O as a medium to generate the bubble. Since CDCl 3 accommodation coefficient is best than that of D 2 O, it is expected a greater collapse force than using D 2 O.To benefit the bubble collapse violence, we diminish the temperature of the liquids.To avoid false neutron detection, we developed a measuring system with high background reject using the characteristic experiment times.No neutrons attributable to Deuterium - Deuterium fusion reaction were measured

  10. The present role of superconductivity in fusion

    International Nuclear Information System (INIS)

    Shimamoto, S.

    1986-01-01

    After completion of large fusion devices in the world, such as JT-60, JET and TFTR, high temperature plasma is proceeding to critical condition for fusion. The devices up to now use mainly conventional magnet. However, for the next generation machine which demonstrates fusion reaction, deuterium-tritium burning, superconducting magnet system is indispensable from view point of both net energy extraction and capacity limitation of power supply. In order to realize such a large and complicated system, a lot of development works is being carried out. This paper describes required parameters of superconducting magnet and helium refrigerator, the state of plasma condition and superconducting magnet. It is shown that the present technology of superconducting magnet is not so far from realization of fusion experimental reactor

  11. Fusion and quasi-elastic processes near the Coulomb barrier

    International Nuclear Information System (INIS)

    Abriola, D.

    1987-01-01

    An overview of the fusion phenomenon below Coulomb barrier is presented. The current theoretical descriptions, emphasizing the relations with direct reactions are discussed. The definition and systematic behaviour of the fusion enhancement below the Coulomb barrier are also presented. The role of coupling to surface degrees of freedom, namely permanent deformations of nuclei, inelastic and transfer channels is shown. The importance of studies describing simultaneously quase-elastic processes and fusion are also shown. (M.C.K.) [pt

  12. Development of target capsules for muon catalyzed fusion experiments

    International Nuclear Information System (INIS)

    Watts, K.D.; Jones, S.E.; Caffrey, A.J.

    1983-01-01

    A series of Muon Catalyzed Fusion experiments has been conducted at the Los Alamos Meson Physics Facility to determine how many fusion reactions one muon would catalyze under various temperature, pressure, contamination, and tritium concentration conditions. Target capsules to contain deuterium and tritium at elevated temperatures and pressures were engineered for a maximum temperature of 540 K (512 0 F) and a maximum pressure of 103 MPa (15,000 psig). Experimental data collected with these capsules indicated that the number of fusion reactions per muon continued to increase with temperature up to the 540-K design limit. Theory had indicated that the reaction rate should peak at approximately 540 K, but this was not confirmed during the experiments. A second generation of capsules which have a maximum design temperature of 800 K (980 0 F) and a maximum design pressure of 103 MPa (15,000 psig) has now been engineered. These new capsules will be used to further study the muon catalysis rate versus deuterium-tritium mixture temperature

  13. Incomplete convolutions in production and inventory models

    NARCIS (Netherlands)

    Houtum, van G.J.J.A.N.; Zijm, W.H.M.

    1997-01-01

    In this paper, we study incomplete convolutions of continuous distribution functions, as they appear in the analysis of (multi-stage) production and inventory systems. Three example systems are discussed where these incomplete convolutions naturally arise. We derive explicit, nonrecursive formulae

  14. Structure information from fusion barriers

    Indian Academy of Sciences (India)

    Pb, using the coupled reaction channel (CRC) method and correct structure information, have been analysed. The barrier distributions derived from these excitation functions including many of the significant channels are featureless, although these channels have considerable effects on the fusion excitation function.

  15. Cold fusion and hot history

    International Nuclear Information System (INIS)

    Lewenstein, B.

    1996-01-01

    The history of cold fusion research following the announcement of the Pons-Fleischmann experiment is described in detail, including all the confusion, responses of scientists, personal impressions, personal quotations, reactions of the media, references to contemporary sources, etc. (P.A.). 5 figs

  16. The conserved glycine residues in the transmembrane domain of the Semliki Forest virus fusion protein are not required for assembly and fusion

    International Nuclear Information System (INIS)

    Liao Maofu; Kielian, Margaret

    2005-01-01

    The alphavirus Semliki Forest virus (SFV) infects cells via a low pH-triggered fusion reaction mediated by the viral E1 protein. Both the E1 fusion peptide and transmembrane (TM) domain are essential for membrane fusion, but the functional requirements for the TM domain are poorly understood. Here we explored the role of the five TM domain glycine residues, including the highly conserved glycine pair at E1 residues 415/416. SFV mutants with alanine substitutions for individual or all five glycine residues (5G/A) showed growth kinetics and fusion pH dependence similar to those of wild-type SFV. Mutants with increasing substitution of glycine residues showed an increasingly more stringent requirement for cholesterol during fusion. The 5G/A mutant showed decreased fusion kinetics and extent in fluorescent lipid mixing assays. TM domain glycine residues thus are not required for efficient SFV fusion or assembly but can cause subtle effects on the properties of membrane fusion

  17. Progress of laser fusion research

    International Nuclear Information System (INIS)

    Yamanaka, Chiyoe

    1988-01-01

    The history of the research on nuclear fusion utilizing laser is described. It started in USSR in 1968, but the full scale start of laser implosion nuclear fusion was in 1972. In Osaka University, nuclear fusion neutrons were detected with a solid deuterium target and the phenomenon of parametric abnormal absorption in laser plasma was found in 1971. The new type target for implosion nuclear fusion ''Canon ball'' was devised in 1975. The phenomenon of the abnormal transmission of laser beam through a thin metal film in a multiple film target was found in 1976, and named ''Osaka effect''. Also the development of lasers has been advanced, and in 1983, a largest glass laser in the world, Gekko 12, with 12 beams, 30 kJ output, 55 TW, was completed. The new target LHART was devised, which enabled the generation of 10 trillion D-T reaction neutrons. Due to the development of high power laser technology, the realization of the new design of fuel pellets, the evaluation of the data by computer simulation, and the realization of new plasma diagnostic method, the research on laser nuclear fusion has developed rapidly, and the attainment of break-even is expected in 1990s. The features of inertial nuclear fusion are enumerated. (Kako, I.)

  18. Cold fusion in perspective

    International Nuclear Information System (INIS)

    Sanford, L.

    1989-01-01

    Since early April a great deal of excitement has been created over the Fleischmann/Pons cold fusion experiment, which if it performs as advertised, could turn out to be mankind's best hope of heading off the energy crisis scheduled for early in the next century. Dozens of groups around the world are now attempting to duplicate the experiment to see if Fleischmann and Pons' discovery is an experimental mistake, an unknown electrochemical effect or a new kind of fusion reaction. This article puts the experiment into the perspective of today and looks at how it might affect the energy scene tomorrow if it should turn out to be commercially exploitable. (author)

  19. Binding of cholesterol and inhibitory peptide derivatives with the fusogenic hydrophobic sequence of F-glycoprotein of HVJ (Sendai virus): possible implication in the fusion reaction

    International Nuclear Information System (INIS)

    Asano, K.; Asano, A.

    1988-01-01

    Specificity of the binding of sterols and related compounds with purified F-protein (fusion protein) of the HVJ (Sendai virus) was studied by binding competition with [ 3 H] cholesterol. Requirement for cholesterol or the A/B ring trans structure and nonrequirement for the 3-hydroxyl group were found in this binding. Binding of 125 I-labeled Z-Phe-Tyr, an inhibitory peptide of viral membrane-cell membrane fusion, was studied by using purified proteins and virions. F-Protein and virions showed a specific binding with the peptide, whereas the result was negative with hemagglutinin and neuraminidase protein. Thermolysin-truncated F-protein (an F-protein derivative deprived of a 2.5-kDa fragment from the N-terminal of the F 1 subunit and without fusogenic activity) exhibited a considerably diminished binding ability both to cholesterol and to inhibitory peptides. Therefore, the N-terminal hydrophobic sequence that was previously assigned as fusogenic seems to be the binding site of these molecules. In support of this, the binding of cholesterol with F-protein was inhibited by Z-Phe-Tyr and other fusion inhibitory peptides, whereas it was not affected with non-fusion-inhibitory Z-Gly-Phe. These results are discussed in relation to the notion that the binding of the N-terminal portion of the F 1 subunit of F-protein with cholesterol in the target cell membranes facilitiates the fusion reaction

  20. Fusion Plasma Physics and ITER - An Introduction (2/4)

    CERN Multimedia

    CERN. Geneva

    2011-01-01

    The second lecture will explore some of the key physics phenomena which govern the behaviour of magnetic fusion plasmas and which have been the subject of intense research during the past 50 years: plasma confinement, magnetohydrodynamic stability and plasma-wall interactions encompass the major areas of plasma physics which must be understood to assemble an overall description of fusion plasma behaviour. In addition, as fusion plasmas approach the “burning plasma” regime, where internal heating due to fusion products dominates other forms of heating, the physics of the interaction between the α-particles produced by D-T fusion reactions and the thermal “background” plasma becomes significant. This lecture will also introduce the basic physics of fusion plasma production, plasma heating and current drive, and plasma measurements (“diagnostics”).

  1. Fusion safety program Annual report, Fiscal year 1995

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Cadwallader, L.C.; Carmack, W.J.

    1995-12-01

    This report summarizes the major activities of the Fusion Safety Program in FY-95. The Idaho National Engineering Laboratory (INEL) is the designated lead laboratory, and Lockheed Idaho Technologies Company is the prime contractor for this program. The Fusion Safety Program was initiated in 1979. Activities are conducted at the INEL, at other DOE laboratories, and at other institutions. Among the technical areas covered in this report are tritium safety, beryllium safety, chemical reactions and activation product release, safety aspects of fusion magnet systems, plasma disruptions, risk assessment failure rate database development, and safety code development and application to fusion safety issues. Most of this work has been done in support of the International Thermonuclear Experimental Reactor (ITER). Also included in the report are summaries of the safety and environmental studies performed by the Fusion Safety Program for the Tokamak Physics Experiment and the Tokamak Fusion Test Reactor and the technical support for commercial fusion facility conceptual design studies. A final activity described is work to develop DOE Technical Standards for Safety of Fusion Test Facilities

  2. Electrodeless, multi-megawatt reactor for room-temperature, lithium-6/deuterium nuclear reactions

    International Nuclear Information System (INIS)

    Drexler, J.

    1993-01-01

    This paper describes a reactor design to facilitate a room-temperature nuclear fusion/fission reaction to generate heat without generating unwanted neutrons, gamma rays, tritium, or other radioactive products. The room-temperature fusion/fission reaction involves the sequential triggering of billions of single-molecule, 6 LiD 'fusion energy pellets' distributed in lattices of a palladium ion accumulator that also acts as a catalyst to produce the molecules of 6 LiD from a solution comprising D 2 O, 6 LiOD with D 2 gas bubbling through it. The D 2 gas is the source of the negative deuterium ions in the 6 LiD molecules. The next step is to trigger a first nuclear fusion/fission reaction of some of the 6 LiD molecules, according to the well-known nuclear reaction: 6 Li + D → 2 4 He + 22.4 MeV. The highly energetic alpha particles ( 4 He nuclei) generated by this nuclear reaction within the palladium will cause shock and vibrations in the palladium lattices, leading to compression of other 6 LiD molecules and thereby triggering a second series of similar fusion/fission reactions, leading to a third series, and so on. The absorption of the kinetic energy in the palladium will, in turn, generate a continuous flow of heat into the heavy water carrier, which would be removed with a heat exchanger. (author)

  3. Electron screening in molecular fusion reactions

    International Nuclear Information System (INIS)

    Shoppa, T.D.

    1996-01-01

    Recent laboratory experiments have measured fusion cross sections at center-of-mass energies low enough for the effects of atomic and molecular electrons to be important. To extract the cross section for bare nuclei from these data (as required for astrophysical applications), it is necessary to understand these screening effects. We study electron screening effects in the low-energy collisions of Z=1 nuclei with hydrogen molecules. Our model is based on a dynamical evolution of the electron wave functions within the TDHF scheme, while the motion of the nuclei is treated classically. We find that at the currently accessible energies the screening effects depend strongly on the molecular orientation. The screening is found to be larger for molecular targets than for atomic targets, due to the reflection symmetry in the latter. The results agree fairly well with data measured for deuteron collisions on molecular deuterium and tritium targets. (orig.)

  4. Incomplete linear tibial fractures in two horses

    International Nuclear Information System (INIS)

    Johnson, P.J.; Allhands, R.V.; Baker, G.J.; Boero, M.J.; Foreman, J.H.; Hyyppa, T.; Huhn, J.C.

    1988-01-01

    Incomplete linear tibial fractures were identified in two horses with the aid of scintigraphy. Both horses were treated successfully by strict stall confinement, and both returned to normal athletic activity. Scintigraphy can be used to facilitate the generally difficult diagnosis of incomplete tibial fractures

  5. Inertial fusion and energy production

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1982-01-01

    Inertial-confinement fusion (ICF) is a technology for releasing nuclear energy from the fusion of light nuclei. For energy production, the most reactive hydrogen isotopes (deuterium (D) and tritium (T)) are commonly considered. The energy aplication requires the compression of a few milligrams of a DT mixture to great density, approximately 1000 times its liquid-state density, and to a high temperature, nearly 100 million 0 K. Under these conditions, efficient nuclear-fusion reactions occur, which can result in over 30% burn-up of the fusion fuel. The high density and temperature can be achieved by focusing very powerful laser or ion beams onto the target. The resultant ablation of the outer layers of the target compresses the fuel in the target, DT ignition occurs, and burn-up of the fuel results as the thermonuclear burn wave propagates outward. The DT-fuel burn-up occurs in about 199 picoseconds. On this short time scale, inertial forces are sufficiently strong to prevent target disassembly before fuel burn-up occurs. The energy released by the DT fusion is projected to be several hundred times greater than the energy delivered by the driver. The present statuds of ICF technology is described

  6. Application of probabilistic risk assessment methodology to fusion

    International Nuclear Information System (INIS)

    Piet, S.J.

    1985-07-01

    Probabilistic Risk Assessment (PRA) tools are applied to general fusion issues in a systematic way, generally qualitatively. The potential value of PRA to general fusion safety and economic issues is discussed. Several important design insights result: possible fault interactions must be minimized (decouple fault conditions), inherently safe designs must include provision for passively handling loss of site power and loss of coolant conditions, the reliability of the vacuum boundary appears vital to maximizing facility availabilty and minimizing safety risk, and economic analyses appear to be incomplete without consideration of potential availability loss from forced outrages. A modification to PRA formalism is introduced, called the fault interaction matrix. The fault interaction matrix contains information concerning what initial fault condition could lead to other fault conditions and with what frequency. Thus, the fault interaction matrix represents a way to present and measure the degree to which a designer has decoupled possible fault conditions in his design

  7. Thinking about the cold fusion fever

    International Nuclear Information System (INIS)

    Kitsunezaki, Akio

    1989-01-01

    The excitement since March 23 on cold fusion seems to be unprecedented evidence that the people of the world are waiting for fusion power with much enthusiasm. Cold fusion is really a surprise because it does not need high temperature and because it seems to be easy to enlarge the test tube into a useful power source if the claim by Professors Pons and Fleischmann at the University of Utah are true. The second announcement of cold fusion came from the Brigham Young University, also in the state of Utah, by Professor Jones, but his report was totally different from that given by Pons and Fleischmann. From the beginning of the 'fever', physicists have been very skeptical about cold fusion. Most of the critics and criticisms are targeted on Pons and Fleischmann rather than Jones, because not only was their paper poor but also their statements have not been scientific. They insisted that the heat came from fusion reaction, but without any scientific proof. They had not carried out the basic control experiment by running the same test with ordinary water instead of heavy water. A meeting on cold fusion was held at JAERI on May 15. At the end of the meeting, the some 260 attendants knew that cold fusion was not conceivable with the current scientific knowledge. (N.K.)

  8. Suction v. conventional curettage in incomplete abortion

    African Journals Online (AJOL)

    Suction v. conventional curettage in incomplete abortion. A randomised controlled trial. D. A. A. VERKUYL, C. A. CROWTHER .Abstract This randomised controlled trial of 357 patients who had had an incomplete abortion compared suction curettage with conventional curettage for evacuation ofthe uterus. The 179 patients ...

  9. Thermonuclear Tokamak plasmas in the presence of fusion alpha particles

    International Nuclear Information System (INIS)

    Anderson, D.; Hamnen, H.; Lisak, M.

    1988-01-01

    In this overview, we have focused on several results of the thermonuclear plasma research pertaining to the alpha particle physics and diagnostics in a fusion tokamak plasma. As regards the discussion of alpha particle effects, two distinct classes of phenomena have been distinguished: the simpler class containing phenomena exhibited by individual alpha particles under the influence of bulk plasma properties and, the more complex class including collective effects which become important for increasing alpha particle density. We have also discussed several possibilities to investigate alpha particle effects by simulation experiments using an equivalent population of highly energetic ions in the plasma. Generally, we find that the present theoretical knowledge on the role of fusion alpha particles in a fusion tokamak plasma is incomplete. There are still uncertainties and partial lack of quantitative results in this area. Consequently, further theoretical work and, as far a possible, simulation experiments are needed to improve the situation. Concerning the alpha particle diagnostics, the various diagnostic techniques and the status of their development have been discussed in two different contexts: the escaping alpha particles and the confined alpha particles in the fusion plasma. A general conclusion is that many of the different diagnostic methods for alpha particle measurements require further major development. (authors)

  10. Some safety considerations of liquid lithium as a fusion breeder material

    International Nuclear Information System (INIS)

    Jeppson, D.W.; Muhlestein, L.D.

    1986-01-01

    Test results and conclusions are presented for the reaction of steam with a high temperature lithium pool and for the reaction of high temperature lithium spray with a nitrogen atmosphere. The reactions are characterized and evaluated in regard to the potential for mobilization of radioactive species associated with the liquid breeder under postulated fusion reactor accident conditions. These evaluations include measured lithium temperature responses, atmosphere temperature and pressure responses, gas consumption and generation, aerosol quantities and particle size characterization, and potentially radioactive species releases. Conclusions are made as to the consequences of these safety considerations for the use of lithium as a fusion reactor breeder material

  11. Barrier for cold-fusion production of superheavy elements

    International Nuclear Information System (INIS)

    Ichikawa, Takatoshi; Iwamoto, Akira; Moeller, Peter; Sierk, Arnold J.

    2005-01-01

    We estimate the fusion-barrier height B fu (two-body) for approaching ions in cold-fusion reactions in a model where the projectile deformation and quadrupole zero-point vibrational energy are taken into account. This barrier height is defined as the barrier energy at the target and projectile separation distance where an original oblate deformation of projectile and/or target caused by a repulsive Coulomb force turns into a large prolate deformation caused by the attractive nuclear force as the target and projectile come closer. The instability develops before touching because the attractive short-range nuclear force overcomes the repulsive Coulomb force and the shape-stabilizing effect of shell structure. The shell structure of the doubly magic 208 Pb target is sufficiently strong that its shape remains very close to spherical in all cases studied here. The fusion potential for approaching ions in the two-body channel is calculated in the macroscopic-microscopic model with the quadrupole vibrational zero-point energy obtained in the WKB approximation. We compare our results with data from 10 experimental cold-fusion reactions and with the Bass barriers. Differences and similarities between the Yukawa-plus-exponential model and the Bass model are discussed. We also calculate five-dimensional potential-energy surfaces for the single compound system and show that well-established fission and fusion valleys are both present. For heavy systems, B fu (two-body) becomes lower than the fission barrier just beyond the ground state of the compound system. In the vicinity of this transition, the optimum collision energy for formation of evaporation residues can be expected to depend in a delicate fashion on the interplay among B fu (two-body) , the fusion valley, the fission barrier of the compound system, and the one- and two-neutron separation energies S 1n and S 2n . We discuss these issues in detail and calculate fission-barrier heights. Except for reactions in which

  12. Exploring dissipative processes at high angular momentum in 58Ni+60Ni reactions

    Directory of Open Access Journals (Sweden)

    Williams E.

    2016-01-01

    Full Text Available Current coupled channels (CC models treat fusion as a coherent quantum-mechanical process, in which coupling between the collective states of the colliding nuclei influences the probability of fusion in near-barrier reactions. While CC models have been used to successfully describe many experimental fusion barrier distribution (BD measurements, the CC approach has failed in the notable case of 16O+208Pb. The reason for this is poorly understood; however, it has been postulated that dissipative processes may play a role. Traditional BD experiments can only probe the physics of fusion for collisions at the top of the Coulomb barrier (L = 0ħ. In this work, we will present results using a novel method of probing dissipative processes inside the Coulomb barrier. The method exploits the predicted sharp onset of fission at L ~ 60ħ for reactions forming compound nuclei with A < 160. Using the ANU’s 14UD tandem accelerator and CUBE spectrometer, reaction outcomes have been measured for the 58Ni+60Ni reaction at a range of energies, in order to explore dissipative processes at high angular momentum. In this reaction, deep inelastic processes have been found to set in before the onset fission at high angular momentum following fusion. The results will be discussed in relation to the need for a dynamical model of fusion.

  13. Liquid metal technology in fusion

    International Nuclear Information System (INIS)

    Torre Cabezas, M. de la; Martin Espigares, M.; Lapena, J.

    1985-01-01

    Lithium (or Li-Pb) is one of the several possible coolants being considered for the blanket of magnetic toroidal fusion reactor, not only because of its good thermal and neutron properties, but also because the tritium required to fuel the reactor can be produced by neutron reactions in the lithium. In this paper two main technology tasks to be proposed in our fusion programme have been identified: 1) the development of impurity monitoring devices for use in lithium and Li-Pb environments; 2) effects of Li and Li-Pb environments on the low cycle fatigue properties of different steels. (author)

  14. Incomplete Antibodies May Reduce ABO Cross-Match Incompatibility: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Mehmet Özen

    2018-02-01

    Full Text Available Objective: Any erythrocyte transfusion among humans having type A or B blood groups is impossible due to antibodies causing fatal transfusion complications. A cross-match test is performed to prevent immune transfusion complications before transfusion. Our hypothesis is that the fragment antibody (Fab part of the antibody (incomplete antibody may be used to prevent an immune stimulus related to the complete antibody. Therefore, we designed a pilot study to evaluate the effectiveness of these incomplete antibodies using cross-match tests. Materials and Methods: Pepsin enzyme and staphylococcal protein A columns were used to cut anti-A and anti-B monoclonal antibodies and purify their Fab (2 fragments, respectively. An Rh-positive erythrocyte suspension with purified anti-A Fab (2 solution and B Rh-positive erythrocyte suspension with purified anti-B Fab (2 solution were combined correspondingly. Cross-match tests were performed by tube and gel centrifugation methods. The agglutination levels due to the anti-A and anti-B Fab (2 antibodies and their effects on the agglutination normally observed with complete antibodies were then measured. Results: No agglutination for the purified incomplete anti-A Fab (2 with A Rh+ erythrocyte and anti-B Fab (2 with B Rh+ erythrocyte combinations was observed in the tube cross-match tests. These agglutination levels were 1+ in two wells in the gel centrifugation cross-match tests. Fab (2-treated erythrocytes were also resistant to the agglutination that normally occurs with complete antibodies. Conclusion: We determined that the Fab (2 fragments of antibodies may not only be used to obtain a mild or negative reaction when compared to complete antibodies, but they might also be used for decreasing ABO incompatibility. Incomplete antibodies might be a therapeutic option in autoimmune hemolytic anemia and they may also be used in solid organ or hematopoietic stem cell transplantation. Therefore, we have planned an

  15. Nuclear fusion in a solid body

    International Nuclear Information System (INIS)

    Romodanov, V.A.; Savin, V.I.; Shakhurin, M.V.; Chernyavskij, V.T.; Pustovit, A.E.

    1991-01-01

    The present work was aimed at investigating a possibility to have a fusion reaction during the interaction of gaseous deuterium with various metals under conditions of glow discharge. It is shown that neutron flux which presumably occurs due to the reaction of nuclear fusion exceeded the background level two times maximum for such materials as Cr, Pd, B, Li. A conclusion is made that for the recording of neutrons which can be generated under bombardment of material surfaces with accelerated ions an additional shielding of standard recorders is required against electromagnetic oscillations both in the input circuits and power supply circuits. A significant increase of tritium concentration in deuterium was recorded (by mass spectrometry and β activity measurement) during the passage of the latter through the metal being bombarded with accelerated ions from glow discharge plasma

  16. Accelerators for Fusion Materials Testing

    Science.gov (United States)

    Knaster, Juan; Okumura, Yoshikazu

    Fusion materials research is a worldwide endeavor as old as the parallel one working toward the long term stable confinement of ignited plasma. In a fusion reactor, the preservation of the required minimum thermomechanical properties of the in-vessel components exposed to the severe irradiation and heat flux conditions is an indispensable factor for safe operation; it is also an essential goal for the economic viability of fusion. Energy from fusion power will be extracted from the 14 MeV neutron freed as a product of the deuterium-tritium fusion reactions; thus, this kinetic energy must be absorbed and efficiently evacuated and electricity eventually generated by the conventional methods of a thermal power plant. Worldwide technological efforts to understand the degradation of materials exposed to 14 MeV neutron fluxes >1018 m-2s-1, as expected in future fusion power plants, have been intense over the last four decades. Existing neutron sources can reach suitable dpa (“displacement-per-atom”, the figure of merit to assess materials degradation from being exposed to neutron irradiation), but the differences in the neutron spectrum of fission reactors and spallation sources do not allow one to unravel the physics and to anticipate the degradation of materials exposed to fusion neutrons. Fusion irradiation conditions can be achieved through Li (d, xn) nuclear reactions with suitable deuteron beam current and energy, and an adequate flowing lithium screen. This idea triggered in the late 1970s at Los Alamos National Laboratory (LANL) a campaign working toward the feasibility of continuous wave (CW) high current linacs framed by the Fusion Materials Irradiation Test (FMIT) project. These efforts continued with the Low Energy Demonstrating Accelerator (LEDA) (a validating prototype of the canceled Accelerator Production of Tritium (APT) project), which was proposed in 2002 to the fusion community as a 6.7MeV, 100mA CW beam injector for a Li (d, xn) source to bridge

  17. Heavy ion reactions at low energies

    International Nuclear Information System (INIS)

    Nemes, M.C.

    1985-01-01

    Some general features of the heavy ion reactions at low energies are presented. Some kinds of processes are studied, such as: elastic scattering, peripherical reactions, deep inelastic collisions and fusion. Both, theoretical and experimental perspectives on this field are discussed. (L.C.) [pt

  18. Quantum Bertrand duopoly of incomplete information

    International Nuclear Information System (INIS)

    Qin Gan; Chen Xi; Sun Min; Du Jiangfeng

    2005-01-01

    We study Bertrand's duopoly of incomplete information. It is found that the effect of quantum entanglement on the outcome of the game is dramatically changed by the uncertainty of information. In contrast with the case of complete information where the outcome increases with entanglement, when information is incomplete the outcome is maximized at some finite entanglement. As a consequence, information and entanglement are both crucial factors that determine the properties of a quantum oligopoly

  19. Characterization of the functional requirements of West Nile virus membrane fusion.

    Science.gov (United States)

    Moesker, Bastiaan; Rodenhuis-Zybert, Izabela A; Meijerhof, Tjarko; Wilschut, Jan; Smit, Jolanda M

    2010-02-01

    Flaviviruses infect their host cells by a membrane fusion reaction. In this study, we performed a functional analysis of the membrane fusion properties of West Nile virus (WNV) with liposomal target membranes. Membrane fusion was monitored continuously using a lipid mixing assay involving the fluorophore, pyrene. Fusion of WNV with liposomes occurred on the timescale of seconds and was strictly dependent on mildly acidic pH. Optimal fusion kinetics were observed at pH 6.3, the threshold for fusion being pH 6.9. Preincubation of the virus alone at pH 6.3 resulted in a rapid loss of fusion capacity. WNV fusion activity is strongly promoted by the presence of cholesterol in the target membrane. Furthermore, we provide direct evidence that cleavage of prM to M is a requirement for fusion activity of WNV.

  20. Some Families of the Incomplete H-Functions and the Incomplete \\overline H -Functions and Associated Integral Transforms and Operators of Fractional Calculus with Applications

    Science.gov (United States)

    Srivastava, H. M.; Saxena, R. K.; Parmar, R. K.

    2018-01-01

    Our present investigation is inspired by the recent interesting extensions (by Srivastava et al. [35]) of a pair of the Mellin-Barnes type contour integral representations of their incomplete generalized hypergeometric functions p γ q and p Γ q by means of the incomplete gamma functions γ( s, x) and Γ( s, x). Here, in this sequel, we introduce a family of the relatively more general incomplete H-functions γ p,q m,n ( z) and Γ p,q m,n ( z) as well as their such special cases as the incomplete Fox-Wright generalized hypergeometric functions p Ψ q (γ) [ z] and p Ψ q (Γ) [ z]. The main object of this paper is to study and investigate several interesting properties of these incomplete H-functions, including (for example) decomposition and reduction formulas, derivative formulas, various integral transforms, computational representations, and so on. We apply some substantially general Riemann-Liouville and Weyl type fractional integral operators to each of these incomplete H-functions. We indicate the easilyderivable extensions of the results presented here that hold for the corresponding incomplete \\overline H -functions as well. Potential applications of many of these incomplete special functions involving (for example) probability theory are also indicated.

  1. A new version of an old modal incompleteness theorem

    NARCIS (Netherlands)

    Vosmaer, J.

    2010-01-01

    Thomason [5] showed that a certain modal logic L⊂ S4 is incomplete with respect to Kripke semantics. Later Gerson [3] showed that L is also incomplete with respect to neighborhood semantics. In this paper we show that L is in fact incomplete with respect to any class of complete Boolean algebras

  2. Structural materials for fusion and spallation sources

    International Nuclear Information System (INIS)

    Cottrell, G.A.; Baker, L.J.

    2003-01-01

    Experimental investigation of neutron-induced irradiation damage in structural materials is fundamental to the development of magnetic confinement fusion. Proposals for the testing of candidate materials are described, indicating that a period of at least 10 years will elapse before a suitable high neutron fluence fusion test facility becomes available. In this circumstance, the possibility that neutron spallation sources could be exploited to shorten the time-scale of fusion materials development is attractive. Although fusion displacement and transmutation reaction rates can be replicated in spallation sources, there are significant differences arising from the harder neutron spectra and the presence of energetic protons. These differences, including higher energy PKA, electron heating effects, transmutation rates and pulsing are described and their consequences discussed, together with the concomitant development of theoretical models, needed to understand the effects. It is concluded that spallation source experiments could make a significant contribution to the database required for the validation of theoretical models, and hence reduce the time scale of fusion materials development

  3. Fusion Nuclear Data activities at FNL, IPR

    OpenAIRE

    P. M. Prajapati; B. Pandey; S. Jakhar; C.V. S. Rao; T. K. Basu; B. K. Nayak; S. V. Suryanarayana; A. Saxena

    2015-01-01

    This paper briefly describes the current fusion nuclear data activities at Fusion Neutronics Laboratory, Institute for Plasma Research. It consist of infrastructure development for the cross-section measurements of structural materials with an accelerator based 14 MeV neutron generator and theoretical study of the cross-section using advanced nuclear reaction modular codes EMPIRE and TALYS. It will also cover the proposed surrogate experiment to measure 55Fe (n, p) 55Mn using BARC-TIFR Pel...

  4. The many languages of subbarrier heavy ion fusion

    International Nuclear Information System (INIS)

    Wolter, H.H.

    1991-01-01

    The different pictures to describe subbarrier fusion are reviewed and related to each other. The direct reaction approach to fusion is developed in a Feshbach picture of open and closed channels and the role of absorptive potentials is discussed. This mono-nuclear picture which treats the degrees of freedom of one nucleus is seen versus a di-nuclear picture where the degrees of freedom of the fusing system are directly treated. Here we have performed a study of multidimensional tunneling which shows the importance of neck formation. We also discuss the problem of dissipation in subbarrier fusion. (author)

  5. Gibbs' theorem for open systems with incomplete statistics

    International Nuclear Information System (INIS)

    Bagci, G.B.

    2009-01-01

    Gibbs' theorem, which is originally intended for canonical ensembles with complete statistics has been generalized to open systems with incomplete statistics. As a result of this generalization, it is shown that the stationary equilibrium distribution of inverse power law form associated with the incomplete statistics has maximum entropy even for open systems with energy or matter influx. The renormalized entropy definition given in this paper can also serve as a measure of self-organization in open systems described by incomplete statistics.

  6. Theoretical study of cross sections of proton-induced reactions on cobalt

    Directory of Open Access Journals (Sweden)

    Mustafa Yiğit

    2018-04-01

    Full Text Available Nuclear fusion may be among the strongest sustainable ways to replace fossil fuels because it does not contribute to acid rain or global warming. In this context, activated cobalt materials in corrosion products for fusion energy are significant in determination of dose levels during maintenance after a coolant leak in a nuclear fusion reactor. Therefore, cross-section studies on cobalt material are very important for fusion reactor design. In this article, the excitation functions of some nuclear reaction channels induced by proton particles on 59Co structural material were predicted using different models. The nuclear level densities were calculated using different choices of available level density models in ALICE/ASH code. Finally, the newly calculated cross sections for the investigated nuclear reactions are compared with the experimental values and TENDL data based on TALYS nuclear code. Keywords: Cobalt, Nuclear Structural Materials, Reaction Cross Section, TENDL Database

  7. The fusion of heavy ions in an interaction potential model

    International Nuclear Information System (INIS)

    Zipper, W.

    1980-01-01

    The paper contains the problems connected with fusion processes in heavy ions collision. Results of experimental fusion data for reactions: 9 Be + 12 C, 6 Li + 28 Si, 9 Be + 28 Si, 12 C + 28 Si, 12 C + 16 O and 16 O + 16 O are presented. Comparison of measured fusion cross sections with predictions of the fusion potential model have been made. The validity of this model for both light systems, like 9 Be + 12 C and heavy systems, like 35 Cl + 62 Ni, have been discussed. In conclusion, it should be stated that fusion cross sections could be correctly predicted by the potential model with a potential describing the elastic scattering data. (author)

  8. Zero-sum games with incomplete definition

    International Nuclear Information System (INIS)

    Sprzeuzkouski, Alain

    1976-01-01

    In this research thesis, the author proposes three methods of resolution of incompletely defined games. According to the first one, combined strategies are introduced in an incompletely defined matrix game. According to the second and new one, a new strategy type (C-strategies) is defined for which the payoff function is always defined but not necessarily unequivocal. This leads to assume the existence of a referee who will decide the payoff assigned to players when they use these C-strategies which generate several possibilities. According to the last one, players are informed of the referee's choice. The three methods are compared, and the author shows that they are equivalent to the conventional method of resolution of matrix games in the case of a completely defined game. In another part, the author applied results obtained for incompletely defined matrix games to the case of multi-stage games with target

  9. Study of fusion mechanism of halo nuclear 11Be+208Pb by applying QMD model

    International Nuclear Information System (INIS)

    Wang Ning; Li Zhuxia

    2001-01-01

    The authors have studied the fusion reaction for 11 Be + 208 Pb near barrier by applying QMD model, and find that in t he fusion reaction induced by halo nuclei there simultaneously exist two mechanisms competing with each other. On one hand, 11 Be is a weakly bound nuclear system and is easily broke up caused by the interaction with target, when it approaches to target, so the fusion cross section is suppressed. On the other hand, several neutrons of 11 Be transfer into 208 Pb and interact with 208 Pb to cause the local radius of 208 Pb increase and result in an enhancement of fusion cross section. The fusion cross sections calculated show an enhancement near barrier, and the calculated results agree with the experimental data reasonably well

  10. Nuclear reactions with 11C and 14O radioactive ion beams

    International Nuclear Information System (INIS)

    Guo, Fanqing

    2004-01-01

    Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2x108 pps intensity on target and an 14O beam of up to 3x104 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au(11C,xn)208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of ?? decays from At isotopes as well as the presence of incomplete fusion reactions probably contribute to specific overpredictions. 15F has been investigated by the p(14O,p)14O reaction with the ERSIKTT technology. Several 14O+p runs have been performed. Excellent energy calibration was obtained using resonances from the p(14N,p)14N reaction in inverse kinematics, and comparing the results to those obtained earlier with normal kinematics. The differences between 14N+p and 14O+p in the stopping power function have been evaluated for better energy calibration. After careful calibration, the energy levels of 15F were fitted with an R-matrix calculation. Spins and parities were assigned to the two observed resonances. This new measurement of the 15F ground state supports the disappearance of the Z = 8

  11. Near and sub-barrier fusion studies with radioactive nuclei: an overview

    International Nuclear Information System (INIS)

    Majumdar, Harashit

    2004-01-01

    Full text: Understanding of the reaction mechanism with radioactive nuclei, e.g., halo nuclei, at near barrier energies appears to be a challenging problem at present. Recent experimental and theoretical investigations of fusion of exotic nuclei with stable targets have yielded new insights into the structure of these nuclei and its effects on the fusion reaction dynamics. One interesting and intriguing result of this type of study is the controversy over fusion enhancement in the presence of strong break-up channels. Other novel information include an increase of break-up cross-sections and weakening or absence of threshold anomaly, related to energy dependence of optical model potentials, in the neighbourhood of the barrier. It is believed that the coupling of the entrance channel to different non-elastic channels (including break-up) is responsible for the above phenomena and these aspects are more prominent in the near barrier region. An overview of the experimental studies of fusion excitation function with RIB will be presented

  12. Near and sub-barrier fusion studies with radioactive nuclei: an overview

    International Nuclear Information System (INIS)

    Majumdar, Harashit

    2004-01-01

    Full Text: Understanding of the reaction mechanism with radioactive nuclei, e.g., halo nuclei, at near barrier energies appears to be a challenging problem at present. Recent experimental and theoretical investigations of fusion of exotic nuclei with stable targets have yielded new insights into the structure of these nuclei and its effects on the fusion reaction dynamics. One interesting and intriguing result of this type of study is the controversy over fusion enhancement in the presence of strong break-up channels. Other novel information include an increase of break-up cross-sections and weakening or absence of threshold anomaly, related to energy dependence of optical model potentials, in the neighbourhood of the barrier. It is believed that the coupling of the entrance channel to different non-elastic channels (including break-up) is responsible for the above phenomena and these aspects are more prominent in the near barrier region. An overview of the experimental studies of fusion excitation function with RIB will be presented

  13. Fusion Safety Program annual report, fiscal year 1994

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Cadwallader, L.C.; Dolan, T.J.; Herring, J.S.; McCarthy, K.A.; Merrill, B.J.; Motloch, C.G.; Petti, D.A.

    1995-03-01

    This report summarizes the major activities of the Fusion Safety Program in fiscal year 1994. The Idaho National Engineering Laboratory (INEL) is the designated lead laboratory and Lockheed Idaho Technologies Company is the prime contractor for this program. The Fusion Safety Program was initiated in 1979. Activities are conducted at the INEL, at other DOE laboratories, and at other institutions, including the University of Wisconsin. The technical areas covered in this report include tritium safety, beryllium safety, chemical reactions and activation product release, safety aspects of fusion magnet systems, plasma disruptions, risk assessment failure rate data base development, and thermalhydraulics code development and their application to fusion safety issues. Much of this work has been done in support of the International Thermonuclear Experimental Reactor (ITER). Also included in the report are summaries of the safety and environmental studies performed by the Fusion Safety Program for the Tokamak Physics Experiment and the Tokamak Fusion Test Reactor and of the technical support for commercial fusion facility conceptual design studies. A major activity this year has been work to develop a DOE Technical Standard for the safety of fusion test facilities

  14. Performance characteristics of a reverse transcriptase-polymerase chain reaction assay for the detection of tumor-specific fusion transcripts from archival tissue.

    Science.gov (United States)

    Fritsch, Michael K; Bridge, Julia A; Schuster, Amy E; Perlman, Elizabeth J; Argani, Pedram

    2003-01-01

    Pediatric small round cell tumors still pose tremendous diagnostic problems. In difficult cases, the ability to detect tumor-specific gene fusion transcripts for several of these neoplasms, including Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/PNET), synovial sarcoma (SS), alveolar rhabdomyosarcoma (ARMS), and desmoplastic small round cell tumor (DSRCT) using reverse transcriptase-polymerase chain reaction (RT-PCR), can be extremely helpful. Few studies to date, however, have systematically examined several different tumor types for the presence of multiple different fusion transcripts in order to determine the specificity and sensitivity of the RT-PCR method, and no study has addressed this issue for formalin-fixed material. The objectives of this study were to address the specificity, sensitivity, and practicality of such an assay applied strictly to formalin-fixed tissue blocks. Our results demonstrate that, for these tumors, the overall sensitivity for detecting each fusion transcript is similar to that reported in the literature for RT-PCR on fresh or formalin-fixed tissues. The specificity of the assay is very high, being essentially 100% for each primer pair when interpreting the results from visual inspection of agarose gels. However, when these same agarose gels were examined using Southern blotting, a small number of tumors also yielded reproducibly detectable weak signals for unexpected fusion products, in addition to a strong signal for the expected fusion product. Fluorescence in situ hybridization (FISH) studies in one such case indicated that a rearrangement that would account for the unexpected fusion was not present, while another case was equivocal. The overall specificity for each primer pair used in this assay ranged from 94 to 100%. Therefore, RT-PCR using formalin-fixed paraffin-embedded tissue sections can be used to detect chimeric transcripts as a reliable, highly sensitive, and highly specific diagnostic assay. However, we

  15. Three-dimensional TDHF calculation for reactions of unstable nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ka-Hae; Otsuka, Takaharu [Tokyo Univ. (Japan). Dept. of Physics; Bonche, P.

    1998-07-01

    The fusion is studied for reactions between a stable and an unstable nuclei with neutron skin. The reactions {sup 16,28}O+{sup 40}Ca and {sup 16}O+{sup 16,28}O are taken as examples, and the three-dimensional time-dependent Hartree-Fock method with the full Skyrme interaction is used. It is confirmed that the fusion cross section in low-energy region is sensitive to the interaction used in the calculation. (author)

  16. Towards a unified description of light ion fusion cross section excitation functions

    International Nuclear Information System (INIS)

    Zimmer, K.W.

    1995-01-01

    A description of light heavy-ion fusion, taking into account both entrance-channel characteristics and compound-nucleus properties, is derived within a unified theory of nuclear reactions. The dependence of the imaginary fusion potential on the level density of the compound nucleus is revealed. The 12 C + 12 C, 12 C + 14 N, 10 B + 16 O and 16 O + 16 O fusion cross sections are calculated for E cm ≤ 120 MeV and compared with experimental data. The excitation energy dependence of the level-density parameter of 24 Mg, 26 Al and 32 S is inferred below 5 MeV/A. A realistic nuclear level-density model, describing the experimental level-density parameters of highly excited nuclei, is shown to be consistent with both the global features and details of the fusion cross section. 12 C + 12 C and 16 O + 16 O fusion cross section oscillations are predicted at large excitation energies, reflecting the structure of the level density of the highly excited light compound nuclei. Differences of the 12 C + 14 N and 10 B + 16 O fusion reaction mechanisms are discussed in terms of specific entrance-channel characteristics. (orig.)

  17. Towards a unified description of light ion fusion cross section excitation functions

    International Nuclear Information System (INIS)

    Zimmer, K.W.; Rebel, H.

    1994-10-01

    A description of light heavy-ion fusion, taking into account both entrace-channel characteristics and compound-nucleus properties, is derived within a unified theory of nuclear reactions. The dependence of the imaginary fusion potential on the level density of the compound nucleus is revealed. The 12 C+ 12 C, 12 C+ 14 N, 10 B+ 16 O and 16 O+ 16 O fusion cross sections are calculated for E cm ≤120 MeV and compared with experimental data. The excitation energy dependence of the level-density parameter of 24 Mg, 26 Al and 32 S is inferred below 5 MeV/A. A realistic nuclear level-density model, describing the experimental level-density parameters of highly excited nuclei, is shown to be consistent with both the global features and details of the fusion cross section. 12 C+ 12 C and 16 O+ 16 O fusion cross section oscillations are predicted at large excitation energies, reflecting the structure of the level density of the highly excited light compound nuclei. Differences of the 12 C+ 14 N and 10 B+ 16 O fusion reaction mechanisms are discussed in terms of specific entrance-channel characteristics. (orig.)

  18. Bringing functions together with fusion enzymes--from nature's inventions to biotechnological applications.

    Science.gov (United States)

    Elleuche, Skander

    2015-02-01

    It is a mammoth task to develop a modular protein toolbox enabling the production of posttranslational organized multifunctional enzymes that catalyze reactions in complex pathways. However, nature has always guided scientists to mimic evolutionary inventions in the laboratory and, nowadays, versatile methods have been established to experimentally connect enzymatic activities with multiple advantages. Among the oldest known natural examples is the linkage of two or more juxtaposed proteins catalyzing consecutive, non-consecutive, or opposing reactions by a native peptide bond. There are multiple reasons for the artificial construction of such fusion enzymes including improved catalytic activities, enabled substrate channelling by proximity of biocatalysts, higher stabilities, and cheaper production processes. To produce fused proteins, it is either possible to genetically fuse coding open reading frames or to connect proteins in a posttranslational process. Molecular biology techniques that have been established for the production of end-to-end or insertional fusions include overlap extension polymerase chain reaction, cloning, and recombination approaches. Depending on their flexibility and applicability, these methods offer various advantages to produce fusion genes in high throughput, different orientations, and including linker sequences to maximize the flexibility and performance of fusion partners. In this review, practical techniques to fuse genes are highlighted, enzymatic parameters to choose adequate enzymes for fusion approaches are summarized, and examples with biotechnological relevance are presented including a focus on plant biomass-degrading glycosyl hydrolases.

  19. Study of 9 Be + 29 Si system nuclear fusion

    International Nuclear Information System (INIS)

    Silva Figueira, M.C. da.

    1991-01-01

    Fusion cross sections for the 9 Be + 29 Si system have been measured in the energy range between 17 and 38 MeV (lab) by detecting the evaporation residues with the time of flight technique. Angular distributions have been measured from 7.5 0 C to 35 0 C in the laboratory frame at E( 9 Be) = 26 and 38 MeV. The measured fusion cross sections are significantly smaller than the total reaction cross sections obtained from fits to the elastic scattering data in the same energy range. Comparison with existing data for compound systems with A= 38 shows that this effect can not be understood in terms of the statistical yrast line of the formed compound nucleus. A systematic analysis of the energy dependence of the ratio between the fusion cross section and the total reaction cross section, for the system 9 Be + 29 Si and many other available in the literature has been performed. The saturation value can be associated to the nucleon or cluster separation energy of the light nuclei participant in the collision, leading to an hindrance of the fusion cross section. (author)

  20. Survey of the population of the entry states in fusion reactons

    International Nuclear Information System (INIS)

    Sarantites, D.G.; Dilmanian, F.A.; Jaeaeskelaeinen, M.

    1982-01-01

    The population of the entry states from fusion reactions induced by 20 Ne and 50 Ti is investigated for a large number of reaction systems. Entrance channel l-distributions leading to fusion are deduced. The limiting angular momentum imparted to the evaporation residues is investigated as a function of Z and A. Fission plays a dominant role in determining the distributions in the evaporation residues. The effect of other mechanisms is also discussed. Prominent variations in the observed population distributions in (E*, M/sub γ/) space are attributed to nuclear structure effects