Search results for "Magnetism"
showing 10 items of 1934 documents
Experimental neutron capture data of 58Ni from the CERN n_TOF facility
2014
The $^{58}$Ni $(n,\gamma)$ cross section has been measured at the neutron time of flight facility n_TOF at CERN, in the energy range from 27 meV up to 400 keV. In total, 51 resonances have been analyzed up to 122 keV. Maxwellian averaged cross sections (MACS) have been calculated for stellar temperatures of kT$=$5-100 keV with uncertainties of less than 6%, showing fair agreement with recent experimental and evaluated data up to kT = 50 keV. The MACS extracted in the present work at 30 keV is 34.2$\pm$0.6$_\mathrm{stat}\pm$1.8$_\mathrm{sys}$ mb, in agreement with latest results and evaluations, but 12% lower relative to the recent KADoNIS compilation of astrophysical cross sections. When in…
Measurement of proton and nitrogen polarization in ammonia and a test of equal spin temperature
1998
The 1996 data taking of the SMC experiment used polarized protons to measure the spin-dependent structure function g(1) of the proton. Three liters of solid granular ammonia were irradiated at the Bonn electron linac in order to create the paramagnetic radicals which are needed for polarizing the protons. Proton polarizations of +/- (90 +/- 2.5)% were routinely reached. An analysis based on a theoretical line shape for spin-1. systems with large quadrupolar broadening was developed which allowed the nitrogen polarization in the ammonia to be determined with a 10% relative error. The measured quadrupolar coupling constant of N-14 agrees well with earlier extrapolated values. The polarization…
Determination of spin, magnetic moment and isotopic shift of neutron rich205Hg by optical pumping
1975
Neutron rich205Hg (T 1/2=5.2 min) was produced and on-line mass separated at the ISOLDE facility at CERN. The polarization achieved by optical pumping via the atomic line (6s 21 S 0↔6s6p 3 P 1,λ=2 537A) was monitored by theβ decay asymmetry. Hyperfine structure and isotopic shift of the205Hg absorption line was determined by Zeeman scanning. In addition a magnetic resonance was performed on the polarized205Hg nuclei in the atomic ground state. The results are: $$I(^{205} Hg) = \tfrac{1}{2}$$ (confirmed);μ I (205Hg)=0.5915 (1)μ N (uncorrected for diamagnetism); isotopic shiftδv204/205=v(205Hg)-v(204Hg)=−1.8 (1) GHz.μ I and IS are discussed briefly in the frame of current literature.
Determination of the isotope shift of115m Cd by a Zeeman scanning method
1975
We have used an optical pumping-Zeeman scanning technique in order to determine the isotope shift in the 3,261 A resonance line of 43-day, spin-11/2115mCd. A sample of ≈5×1012 atoms was aligned in the1S0 diamagnetic ground state by optically pumping the sample with one selected Zeeman-scanned component of the3P1−3,261 A resonance line from a114Cd lamp. The alignment was detected through the modulation of the pumping beam at the nuclear resonance frequency. Thus by Zeeman scanning theF = 9/2 component of the3P1 level and using previously determinedA- andB-values, we findδ5v(114–115m (9/2))= −4,234(48) MHz and114Cd-115mCd isotope shift = 87(48) MHz. We calculate a staggering parameterγ(115mCd…
Molecule-based ferromagnetic conductors: Strategy and design
2008
The design and study of hybrid crystalline solids in the search for multifunctional materials is one of the most appealing possibilities where molecule-based materials offer striking advantages: from the combination of molecular building blocks with the desired tailor-made chemical and physical properties. In this review we will cover all aspects of the so-called molecular ferromagnetic conductors, built from combination in a single compound of organic cationic radicals, able to give rise to conducting architectures, with polymeric anionic metal complexes, able to give rise to ferromagnetism. The relevant successes and drawbacks of this approach will be highlighted and discussed in detail.
Magnetic predissociation in Te 2 B 1 u
1997
We report a registration of magnetic predissociation (MPD) of electronically excited molecules via peculiarities in magnetic field B induced alignment-orientation conversion (AOC). Non-linear magnetic energy shift and heterogeneous MPD produce dispersion type fluorescence circularity signals C(B) of different sign. Measurements on B 1 u - , v(J) equals 2(96) state of 130 Te 2 yielded natural C v het equals plus or minus 6 s -1/2 and magnetic (alpha) v het equals minus or plus 9 multiplied by 10 3 s -1/2 T -1 rate constants of heterogeneous PD, supposing that the B1 u - state PD takes place through O u - state continuum.
In-flight separation with gas-filled systems
1997
Abstract The application of gas-filled recoil separators in the study of fusion evaporation products from heavy ion induced reactions will be discussed. Practical methods for estimating the average magnetic rigidity of fusion products and target-like nuclei will be presented. Examples will be given of typical background intensities observed in studies of heavy elements. The merits of gas-filled devices in comparison with other in-flight separators will be discussed. Selected recent applications in the fields of heavy element research and in-beam gamma-ray spectroscopy will be presented, and finally, some future projects will be discussed.
Ion-optical layout of a powerful next-generation pre-separator for in-flight separation of relativistic rare isotopes
2006
Abstract Rare isotope beams can be efficiently produced at relativistic energies via projectile fragmentation and projectile fission. Magnetic rigidity analysis in combination with atomic energy loss ( Bρ –Δ E – Bρ method) in profiled matter placed at dispersive focal planes represents the tool for spatial separation in flight. The next-generation in-flight separators at high energies will consist of multiple degrader stages to provide intense monoisotopic fragment beams of all elements up to uranium. The pre-separator layout with the first degrader system holds many technical challenges, e.g. to handle the high-power primary beams characterized by a large range in time structure, from a DC…
The Influence of a Magnetic Field on the Formation of Corrosion Defects in Selected Metals and Steels, Analysed Using Positron Annihilation Method
2014
The method of positron lifetime measurement was used to analyse the in uence of a magnetic eld on the kinetics of corrosion defect formation in near-surface layers of iron, titanium as well as S20 and S0H18N9 steel grades. The listed metals, which belong to ferroand paramagnetic materials, have di erent sensitivity to corrosion. It was found that not only the presence of a magnetic eld, but also its direction in uence the dimensions and the concentration of defects formed during corrosion.