GSI EXPERIMENTS ON SYNTHESIS AND NUCLEAR STRUCTURE INVESTIGATIONS OF HEAVIEST NUCLEI

2006 ◽  
Vol 15 (02) ◽  
pp. 284-291 ◽  
Author(s):  
F. P. HEßBERGER
Keyword(s):  
Nuclear Structure ◽  
Atomic Number ◽  
Cross Sections ◽  
Single Particle ◽  
Cold Fusion ◽  
Experimental Program ◽  
Fusion Reactions ◽  
Decay Spectroscopy ◽  
Structure Investigations ◽  
Actinide Targets

The method of 'cold' fusion reactions has been applied successfully to synthesize isotopes of elements up to Z =113. However, the cross sections were found to decrease nearly exponential with increasing atomic number. The production of isotopes up to Z =118 using 48 Ca - projectiles and actinide targets was claimed from experiments performed at the Dubna Gasfilled Separator (DGFRS). Attempts to confirm the results from one of the used reactions (48 Ca + 238 U ) have been performed at other laboratories. The results of the different experiments are compared. In order to increase our knowledge on the structure of heaviest nuclei an experimental program on α - γ - decay spectroscopy of transfermium isotopes was started at SHIP, GSI. Results on trends in single particle levels in odd mass einsteinium isotopes as well as on the identification of a (possible) K -isomer in 252 No will be presented.

Entrance Channel Dependence of Production Cross Sections of Superheavy Nuclei in Cold Fusion Reactions

2005 ◽  
Vol 22 (4) ◽  
pp. 846-849 ◽  
Author(s):  
Feng Zhao-Qing ◽  
Jin Gen-Ming ◽  
Fu Fen ◽  
Zhang Feng-Shou ◽  
Jia Fei ◽  
...  
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Cold Fusion ◽  
Entrance Channel ◽  
Superheavy Nuclei ◽  
Fusion Reactions

CROSS SECTIONS CALCULATED FOR COLD FUSION REACTIONS WITH EMISSION OF ONLY ONE NEUTRON FOR PRODUCING THE HEAVIEST ELEMENTS

2005 ◽  
Vol 14 (03) ◽  
pp. 373-375 ◽  
Author(s):  
ROBERT SMOLAŃCZUK
Keyword(s):  
Cross Sections ◽  
Level Density ◽  
Cold Fusion ◽  
Entrance Channel ◽  
Fusion Reactions ◽  
Coupled Channels ◽  
Dynamical Deformation ◽  
Channel Effects ◽  
The Difference ◽  
Heaviest Elements

Entrance-channel effects in cold fusion reactions that lead to heavy and superheavy nuclei are discussed in the framework of the coupled-channels theory. Dynamical deformation besides collective excitations is taken into account in the entrance channel. Exit channel is described by using the modified statistical model that takes into account the difference between the level density in the equilibrium configuration and that in the saddle-point configuration. Comparison of the calculated fusion cross sections with experimental data is given.

COLD FUSION REACTIONS USING NEUTRON-RICH PROJECTILES

2013 ◽  
Vol 22 (08) ◽  
pp. 1350061 ◽  
Author(s):  
A. SULAKSONO
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Estimation Method ◽  
Cold Fusion ◽  
Evaporation Residue ◽  
Fusion Reactions ◽  
Fusion Barrier ◽  
The Cross ◽  
Evaporation Residues

This paper studies the formation cross-sections of super heavy (SH) nuclei in some cold fusion reactions of radioactive neutron-rich projectiles with double-magic 208 Pb target. In this study, the cross-sections of capture, fusion and evaporation residues in one- and two-neutron (1n and 2n) channels are calculated by using neutron-rich Fe , Ni and Zn projectiles are compared to the cross-sections calculated using stable Fe , Ni and Zn projectiles. The heights of fusion barrier and their positions in all reactions considered in this study are also compared to the heights and positions calculated using the estimation method proposed by Dutt and Puri. For cold fusion reactions with stable Fe , Ni and Zn projectiles, the heights of fusion barrier and the cross-sections of evaporation residues in 1n and 2n channels are compared to their corresponding experimental data. In general, for reactions using projectiles with the same proton number, the neutron-rich projectile is found to yield relatively-heavier mass of SH nucleus and larger evaporation residue cross-section, compared to those of the corresponding stable projectiles. However, in certain reactions, the cross-sections of neutron-rich projectile can be slightly larger or slightly smaller than that of the corresponding stable projectile. This behavior is highly affected by the charge of projectile and the fission barrier of the formed compound nucleus (CN). In addition, the 292114 is found to be the heaviest compound nucleus formed in cold fusion reaction by using neutron-rich nuclei as the projectile, but the cross-section of evaporation residue in one-neutron channel is still around few pico barns (pb).

CALCULATIONS OF CROSS SECTIONS FOR THE SYNTHESIS OF SUPER-HEAVY NUCLEI IN COLD FUSION REACTIONS

2004 ◽  
Vol 13 (01) ◽  
pp. 261-267 ◽  
Author(s):  
W. J. ŚWIATECKI ◽  
K. SIWEK-WILCZYŃSKA ◽  
J. WILCZYŃSKI
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Free Parameter ◽  
Cold Fusion ◽  
One Dimension ◽  
Brownian Diffusion ◽  
Heavy Nuclei ◽  
Fusion Reactions ◽  
Super Heavy Nuclei

The fusion cross sections are considered to be given by the product of three factors: the cross section to overcome the Coulomb barrier, the probability for the resulting system to reach the compound nucleus configuration by diffusion, and the probability for the compound nucleus to survive fission. The first and third factors are treated by more or less conventional equations, and the second by Brownian diffusion in one dimension. Adjusting one free parameter in the theory one can reproduce the twelve measured cross sections to within a factor of two.

EXPERIMENTS ON SUPERHEAVY ELEMENTS

2010 ◽  
Vol 19 (04) ◽  
pp. 483-492 ◽  
Author(s):  
SIGURD HOFMANN
Keyword(s):  
Experimental Investigation ◽  
Cold Fusion ◽  
Superheavy Elements ◽  
Fusion Reactions ◽  
Neutron Rich Isotopes ◽  
Actinide Targets

An overview of present experimental investigation of superheavy elements is given. Using cold fusion reactions which are based on lead and bismuth targets, relatively neutron deficient isotopes of the elements from 107 to 113 were synthesized at GSI in Darmstadt, Germany, and/or at RIKEN in Wako, Japan. In hot fusion reactions of 48 Ca projectiles with actinide targets more neutron rich isotopes of the elements from 112 to 116 and even 118 were produced at FLNR in Dubna, Russia. Recently, part of these data which represent the first identification of nuclei located on the predicted island of SHEs were confirmed in two independent experiments. The data are compared with theoretical descriptions.

MASS AND LIFETIME MEASUREMENTS AT THE PRESENT ESR FACILITY

2009 ◽  
Vol 18 (02) ◽  
pp. 323-334 ◽  
Author(s):  
YURI A. LITVINOV
Keyword(s):  
Mass Spectrometry ◽  
Single Particle ◽  
Experimental Methods ◽  
Lifetime Measurements ◽  
Time Resolved ◽  
Particle Decay ◽  
Decay Properties ◽  
Decay Spectroscopy ◽  
Beta Decays ◽  
Charged Ions

Mass and lifetime measurements of stored exotic nuclei is one of the successful experimental programs at the FRS-ESR facility of GSI, Darmstadt. Two experimental techniques, namely Isochronous and time-resolved Schottky mass spectrometry have been developed. Nuclides in a very broad range of half-lives starting from stable down to only a few ten microseconds can be addressed. Single stored ions can be measured which makes these techniques highly efficient. More than 1100 atomic masses have been measured meanwhile. Half-life measurements are performed with bare and few-electron ions. Decay properties of such highly-charged ions can be dramatically different from the ones known in neutral atoms. Single-particle decay spectroscopy has been developed for investigations of two-body beta decays. A brief description of the experimental methods and recent results will be presented. Future experiments at the present facility and the perspectives with the new NuSTAR/ILIMA project at FAIR will be outlined.

scholarly journals Fusion cross-sections for inertial fusion energy

2004 ◽  
Vol 22 (4) ◽  
pp. 469-477 ◽  
Author(s):  
XING ZHONG LI ◽  
BIN LIU ◽  
SI CHEN ◽  
QING MING WEI ◽  
HEINRICH HORA
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Light Nucleus ◽  
Resonant Tunneling ◽  
Fusion Energy ◽  
Inertial Fusion ◽  
Inertial Fusion Energy ◽  
Fusion Reactions ◽  
Tunneling Model ◽  
New Formula

The application of selective resonant tunneling model is extended from d + t fusion to other light nucleus fusion reactions, such as d + d fusion and d + 3He. In contrast to traditional formulas, the new formula for the cross-section needs only a few parameters to fit the experimental data in the energy range of interest. The features of the astrophysical S-function are derived in terms of this model. The physics of resonant tunneling is discussed.

scholarly journals A new method for measuring optical scattering properties of atmospherically relevant dusts using the Cloud and Aerosol Spectrometer with Polarization (CASPOL)

2013 ◽  
Vol 13 (3) ◽  
pp. 1345-1356 ◽  
Author(s):  
A. Glen ◽  
S. D. Brooks
Keyword(s):  
Cross Sections ◽  
Atmospheric Aerosols ◽  
Single Particle ◽  
Global Climate ◽  
Optical Scattering ◽  
Measurement Tool ◽  
Optical Signature ◽  
New Instrument ◽  
The Difference ◽  
Atmospherically Relevant

Abstract. Atmospheric aerosols have major impacts on regional and global climate through scattering and absorption of solar radiation. A new instrument, the Cloud and Aerosol Spectrometer with Polarization (CASPOL) from Droplet Measurement Technologies measures light scattered by aerosols in the forward (4° to 12°) and backward (168° to 176°) directions, with an additional polarized detector in the backward direction. Scattering by a single particle can be measured by all three detectors for aerosols in a broad range of sizes, 0.6 μm < diameter < 50 μm. The CASPOL is a unique measurement tool, since unlike most in-situ probes, it can measure optical properties on a particle-by-particle basis. In this study, single particle CASPOL measurements for thirteen atmospherically relevant dusts were obtained and their optical scattering signatures were evaluated. In addition, Scanning Electron Microscopy (SEM) was used to characterize the shape and morphology of each type of dust. The total and polarized backscatter intensities varied with particle size for all dust types. Using a new optical signature technique all but one dust type could be categorized into one of three optical scattering groups. Additionally, a composite method was used to derive the optical signature of Arizona Test Dust (ATD) by combining the signatures of its major components. The derived signature was consistent with the measured signature of ATD. Finally, calculated backscattering cross sections for representative dust from each of the three main groups were found to vary by as much as a factor of 7, the difference between the backscattering cross sections of white quartz (5.3 × 10−10 cm−2) and hematite (4.1 × 10−9 cm−2).

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