Search results for "Hyperfine"
showing 10 items of 428 documents
High-power pulsed dye laser with Fourier-limited bandwidth
1986
A high-peak-power, narrow-linewidth light source with a homogeneous beam profile has been constructed by modifications to a commercially available pulsed-dye-laser system. Output pulses of up to 10 mJ were generated with linewidths of about 50 MHz for 12-nsec pulses. The pulse-to-pulse frequency stability was better than the linewidth, and the center frequency could be scanned over a frequency range of 142.5 GHz at a wavelength of 600 nm. The performance of the system was demonstrated by observing the 6s2 1S0–6s7s1S0 transition in atomic mercury at 2λ = 312.8 nm and the 6s2S1/2–8s2S1/2 transition in atomic gold at 2λ = 308.9 nm using up to 1 mJ of frequency-doubled output for two-photon non…
Mass-independent analysis of the stable isotopologues of gas-phase titanium monoxide – TiO
2021
More than 130 pure rotational transitions of $^{46}$TiO, $^{47}$TiO, $^{48}$TiO, $^{49}$TiO, $^{50}$TiO, and $^{48}$Ti$^{18}$O are recorded using a high-resolution mm-wave supersonic jet spectrometer in combination with a laser ablation source. For the first time a mass-independent Dunham-like analysis is performed encompassing rare titanium monoxide isotopologues, and are compared to results from high-accuracy quantum-chemical calculations. The obtained parametrization reveals for titanium monoxide effects due to deviations from the Born-Oppenheimer approximation. Additionally, the dominant titanium properties enable an insight into the electronic structure of TiO by analyzing its hyperfin…
The Effect of Spectral Diffusion on the Saturation Transient Regime
1985
Saturation kinetics of inhomogeneous resonance lines has been investigated in very dilute ruby samples at T=4.2°K by the saturation transient technique. Experimental evidence of the effectiveness of intraline spectral diffusion is reported. Satisfactory agreement is found between the experimental results and a theoretical model in which spectral diffusion is ascribed to the time fluctuations of the hyperfine field. Spectral diffusion times of the order of 10-5 sec are determined.
Laser spectroscopy of cooled zirconium fission fragments
2002
The first on-line laser spectroscopy of cooled fission fragments is reported. The $^{\mathrm{96}\mathrm{--}\mathrm{102}}\mathrm{Z}\mathrm{r}$ ions, produced in uranium fission, were extracted and separated using an ion guide isotope separator. The ions were cooled and bunched for collinear laser spectroscopy by a gas-filled linear Paul trap. New results for nuclear mean-square charge radii, dipole, and quadrupole moments are reported across the $N=60$ shape change. The mean-square charge radii are found to be almost identical to those of the Sr isotones and previously offered modeling of the radial changes is critically reviewed.
On the sensitivity of ion traps for spectroscopic applications
1979
Ba+ ions, created by surface ionization near one endcap of an rf quadrupole trap were slowed down by collisions with the background gas. At He pressures of 10−6 mbar or more 2% of the primary ions could be trapped. The sensitivity of ion detection by fluorescence radiation allows spectroscopic experiments, starting from less than 107 particles. The observation of the ground-state hyperfine splitting of137Ba+ is given as an example.
Collinear Laser Spectroscopy on Fast Atomic Beams
1978
In collinear geometry we have observed laser-excited, narrow resonances in fast beams of Na and Cs atoms obtained from ion beams by charge transfer collisions. Being very sensitive, the method is suited for measuring isotope shifts and hyperfine structure of isotopes far from stability provided by on-line mass separators. It may be used furthermore to study inelastic charge transfer from the energy-loss spectrum of the Doppler-shifted lines.
Isotope shifts and hyperfine structure in the transitions of gadolinium
2000
High-resolution resonance ionization mass spectrometry has been used to measure isotope shifts and hyperfine structure in all (J = 2-6) and the transitions of gadolinium (Gd I). Gadolinium atoms in an atomic beam were excited with a tunable single-frequency laser in the wavelength range of 422-429 nm. Resonant excitation was followed by photoionization with the 363.8 nm line of an argon ion laser and resulting ions were mass separated and detected with a quadrupole mass spectrometer. Isotope shifts for all stable gadolinium isotopes in these transitions have been measured for the first time. Additionally, the hyperfine structure constants of the upper states have been derived for the isotop…
A New Sensitive Technique for Laser Spectroscopic Studies of Radioactive Rare-Gas Isotopes
1987
The concept of laser ionization has been widely used in spectroscopy studies and for the detection of minute samples of atoms. Being based on ion counting, it avoids the sensitivity problems of conventional fluorescence spectroscopy, which are due to low detection efficiency and large background from scattered laser light. We report the first application of an alternative ionization scheme which we have developed for collinear laser spectroscopy on fast atomic beams /1/. Here the increase in sensitivity has considerably enlarged the range of isotopes very far from stability, for which nuclear moments and radii can be investigated in hyperfine structure and isotope shift measurements.
Charge trapping processes and energy transfer studied in lead molybdate by EPR and TSL
2019
Abstract Charge trapping and energy transfer processes are investigated in PbMoO4 single crystals by electron paramagnetic resonance (EPR) and wavelength-resolved thermally stimulated luminescence (TSL) in a correlated manner. New signals produced by two differently perturbed Mo5+ centers (Mo2 and Mo3) were observed in EPR spectra measured in the crystals after 420 nm light irradiation. Two sets of spin-Hamiltonian parameters, g tensor and the 95,97Mo, 207Pb (super) hyperfine tensors, have been determined and analyzed in terms of crystal field and LCAO-MO theories. A significant overlap of the Mo 5d1 and 6s6p ligand Pb orbitals was deduced for the Mo3 whereas the Mo2 center seemed to be not…
Peculiarities of Forming of Magnetic Hardening in Sintered Nd15Fe76.2Ti1.0Al0.8B7 Permanent Magnet by Ageing
1999
Variations of the intrinsic coercivity ( i H c ) with ageing (at 293 to 1173 K for 0.45 to 57.6 ks) of sintered Nd 15 Fe 76.2 Ti 1.0 Al 0.8 B 7 have been investigated. The tests indicated minimum and maximum of intrinsic coercivity ( i H min c and i H max c ) at temperatures 725 K and 1025 K, respectively. The observed behaviour of i H c has been compared with microhardness measurements and microstructure observations (SEM, EDAX, domain structure (DS) and room temperature Mossbauer spectroscopy). SEM and DS investigations gave hints to a change in microstructure. Fitting of the Mossbauer spectra of permanent magnets for different i H c has shown that the magnetic hyperfine field Bhf of 8j2 …