Search results for "nuclear fusion"
showing 10 items of 437 documents
Hyperfine shifts for cesium in Argon at high density
1974
An optical pumping experiment was performed to obtain precise hfs shifts for Cs in Argon. The shifts measured include a term quadratic in the densityρ and a large temperature coefficient. The coefficients of the expansionδv/v0=a ρ+bρ2 area(80 °C)=−29.8(6)x10−9(Torr−1(0°C))b(80 °C)=+11(2)x10−14(Torr−2(0 °C)).
Orientation of199mHg by optical pumping detected by ?-radiation anisotropy
1975
199mHg was produced and mass separated at the ISOLDE facility (CERN). Nuclear orientation achieved by optical pumping via the resonance line 6s21S0→6s6p3P1,λ=2537A was monitored by means of the anisotropy of theγ-radiation emitted in the cascade199mHg(I=13/2+) $${}^{199m}Hg(I = 13/2^ + )\xrightarrow[{M4}]{}{}^{199*}Hg(I = 5/2^ - )\xrightarrow[{E2}]{}{}^{199}Hg(I = 1/2^ - ).$$ 199*Hg(I=5/2−)199Hg(I=1/2−).
Low-energy fission investigated in reactions of 750 AMeV 238U-ions with Pb and Be targets
1996
Charge distributions of fragments from low energy nuclear fission are investigated in reactions of highly fissile238U projectiles at relativistic energies (750 A·MeV) with a heavy (Pb) and a light (Be) target. The fully stripped fission fragments are separated by the Fragment Separator (FRS). Their high kinetic energies in the laboratory system allow the identification of all atomic numbers by using Multiple-Sampling Ionization Chambers (MUSIC). The elemental distributions of fragments observed at larger magnetic rigidities than the238U projectiles show asymmetric break-up and odd-even effects. They indicate a low energy fission process, induced mainly by dissociation in the electro-magneti…
A coupled channel calculation of the double-?(1 236) component of the deuteron
1975
TheΔΔ-component of the deuteron is calculated in a full coupled channel calculation including a diagonalΔ-Δ-interaction and compared to the impulse approximation. Without a diagonalΔ-Δ-interaction both methods give very similar results while inclusion of theΔ-Δ-interaction leads to a decrease of the (ΔΔ)-probability of about 25%. The main uncertainties originate from limited knowledge of coupling constants and cut-off ranges. Accordingly the (ΔΔ)-probability varies between 0.3 and 1 percent.
A study of coupled-reaction channel effects in the36S +37Cl system, hybridization between single particle orbits
1996
Elastic and inelastic scattering as well as transfer transitions involving a valence proton in thesd- andfp- shell orbits are studied in the interaction of37Cl +36S at ECM=50 MeV. Experimental angular distributions of single particle states of37Cl (elastic and inelastic transfer) are presented with a CRC analysis. In the CRC calculations the effects of inelastic and transfer couplings are studied using known spectroscopic information. In the CRC analysis six single particle bound states and the collective 2+ excitation of36S are included in the coupling scheme. Higher order coupling effects are found to be important. A distinct effect, the mixing of single particle states (of different pari…
Untersuchungen zur Mehrfach-Emission von Sekund�relektronen
1964
CuBe- and NaCl-targets are bombarded by single electrons (100–600 eV). The secondary electrons accelerated by 40 kV strike the crystal of a scintillation counter, backed by a multichannel analyser. The probabilityP n of emission ofn=0, 1, 2, 3, ... secondaries can be found from the pulse height distribution. The probability distributionP n =f(n) shows a characteristic deviation from aPoisson's distribution. There was no evidence that there is a preference for even numbers ofn as found byBarrington andAnderson.
New microsecond isomers in 189, 190Bi
2001
New microsecond isomers in the neutron-deficient isotopes 189g, 190Bi have been identified after in-flight separation by the velocity filter SHIP. The evaporation residues were identified on the basis of delayed recoil-γ/X-ray, recoil-γ/X-ray-α and excitation function measurements. The systematics of the [ π1i 13/2]13/2+ excited states in the odd-mass Bi nuclei is discussed.
Radiative capture of protons by the deformed nuclide232Th
1986
The excitation function for the radiative capture232Th(p, γ)233Pa has been determined in the proton energy range 7 to 20 MeV by an activation method. The results are compared with a compound nucleus model prediction and earlier experimental data for another deformed nuclide176Yb. As in previous cases an enhancement over the CN-model prediction is observed and the excitation of the giant dipole resonance via the direct-semidirect reaction process is a likely explanation. Supplementary measurements of the232Th (p, f) excitation function in the proton energy range 11–20 MeV have been performed.
Mechanisms Suppressing Superheavy Element Yields in Cold Fusion Reactions.
2019
Superheavy elements are formed in fusion reactions which are hindered by fast nonequilibrium processes. To quantify these, mass-angle distributions and cross sections have been measured, at beam energies from below-barrier to 25% above, for the reactions of $^{48}\mathrm{Ca}$, $^{50}\mathrm{Ti}$, and $^{54}\mathrm{Cr}$ with $^{208}\mathrm{Pb}$. Moving from $^{48}\mathrm{Ca}$ to $^{54}\mathrm{Cr}$ leads to a drastic fall in the symmetric fission yield, which is reflected in the measured mass-angle distribution by the presence of competing fast nonequilibrium deep inelastic and quasifission processes. These are responsible for reduction of the compound nucleus formation probablity ${P}_{CN}$ …
Study of the 2n-evaporation channel in the 4,6He+206,208Pb reactions
2009
Abstract Excitation functions of the reaction products were measured for the reactions induced by 4,6 He projectiles on 208,206 Pb targets, leading to the same compound nucleus. This was accomplished by using the stacked-foil activation technique. The identification of the reaction products (accumulated in the Pb targets) was done by their radioactive α -decays. The excitation functions for the various products were obtained at energies including the sub-Coulomb barrier region. A large value of the fusion cross section was observed in the case of the reaction induced by the weakly bound 6 He projectile.