First experiments with the FUSION detector Fekou-Youmbi, V.; Sida, J.L.; Alamanos, N. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/1999, Letnik:
437, Številka:
2
Journal Article
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The Fusion Utility for Secondary Ions (FUSION) has been built to measure the fusion–fission cross section induced by radioactive beams at energies around the barrier. A set of 10 parallel plate ...avalanche counters measures the fission fragments which are stopped therein. Twenty plastic scintillators, surrounding the inner shell of PPACs, detect the eventual residue from the projectile. This detector could work in different geometry and allow measurements of low cross section with very weak beams. The measurements at GANIL of the fission cross sections at barrier energies for
9,11Be on U are reported.
The production of primary residual nuclei in the reaction 1
A
GeV
208Pb on proton has been studied by measuring isotopic distributions for all elements from titanium (
Z=22) to lead (
Z=82). ...Kinematical properties of the residues were also determined and used to disentangle the relevant reaction mechanisms, spallation (projectile fragmentation) and fission. The fragment separator FRS at GSI, Darmstadt, was used to separate and identify the reaction products. The measured production cross sections are highly relevant for the design of accelerator-driven subcritical reactors and for the planning of future radioactive-beam facilities.
Spallation residues produced in 1 GeV per nucleon 208Pb on proton reactions have been studied using the Fragment Separator facility at GSI. Isotopic production cross sections of elements from 61Pm to ...82Pb have been measured down to 0.1 mb with a high accuracy. The recoil kinetic energies of the produced fragments were also determined. The obtained cross sections agree with most of the few existing gamma-spectroscopic data. The data are compared with different intranuclear-cascade and evaporation-fission models. Drastic deviations were found for a standard code used in technical applications.
The spallation of Fe-56 in collisions with hydrogen at 1A GeV has been studied in inverse kinematics with the large-aperture setup SPALADIN at GSI. Coincidences of residues with low-center-of-mass ...kinetic energy light particles and fragments have been measured allowing the decomposition of the total reaction cross section into the different possible deexcitation channels. Detailed information on the evolution of these deexcitation channels with excitation energy has also been obtained. The comparison of the data with predictions of several deexcitation models coupled to the INCL4 intranuclear cascade model shows that only GEMINI can reasonably account for the bulk of collected results, indicating that in a light system with no compression and little angular momentum, multifragmentation might not be necessary to explain the data.
Fission Fragments from 1 A GeV $^{238}$U ions impinging a hydrogen target were studied using the fragment separator FRS from GSI for magnetic selection including ray-tracing, and $\Delta$E-ToF ...techniques. From the kinematics of the fragments, binary fission can be assigned as production process up to very heavy fragments. Fission fragments were identified as far as $^{184}$Re for the first time. Cross sections are measured and found in the range of 500 $\mu$b to 5 $\mu$b. Isobaric cross sections decrease smoothly with increasing mass. Beyond tungsten, fission fragments are hidden in the more abundant spallation evaporation residues. Fission cross sections of 283 isotopes of Gd to Re in the mass range 147 to 184 were obtained. All fragments result from fission of excited parent nuclei and after emission of secondary neutrons
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