V Helbig

Temperature tuned distributed feedback dye laser with high repetition rate

A pulsed subnanosecond laser system is described which is tunable over the spectral range from 450 to 650 nm with a bandwidth of ~0.006 nm and can be operated with a repetition rate of up to 200 Hz. It consists of a mirror tuned distributed feedback dye laser which is directly pumped by a XeCl excimer laser. Fine tuning and accurate stabilization of the dye laser wavelength are performed by electronically controlling the temperature of the dye liquid. The long-time stability of the laser wavelength is 0.0028 nm; this is achieved by a novel mechanical and electronic arrangement.

Lifetimes of excited states of neutral titanium and vanadium

Lifetimes of 26 atomic levels of titanium I and vanadium I have been determined using selective pulsed laser excitation of the atoms in an atomic beam and applying the delayed coincidence method for registration.

Radiative lifetimes of neutral and singly ionized atoms of refractory elements

Picosecond laser-induced fluorescence spectroscopy and a pulsed hollow cathode discharge are applied to measure 66 radiative lifetimes of Ta II, Ti II, Ce II, Zr II, Zr I, and Fe I levels. In the present investigation systematic influences like polarization and magnetic field effects, radiation trapping, quenching and the duration of the exciting laser pulse are considered in the data analysis. The selective laser excitation of the levels under investigation is performed by a frequency-stabilized distributed feedback dye laser system and the fluorescence is recorded by photon counting technique to ensure best sensitivity and time-resolution. The typical pulse duration is 100 ps and the spectral bandwidth 0.006 nm. The absolute accuracy of the data is 3 to 6%.

Lifetime measurements of V II levels using tunable subnanosecond UV-dye-laser pulses

13 radiative Lifetimes of V II levels are reported. They are measured by selective laser excitation and time resolved observation of the fluorescence. The short-lived z 5Dj0 were excited by tunable dye laser pulses of less than 1 ns (FHWD) duration and a repetition rate of up to 100 Hz.

Radiative lifetimes of Ta II

Abstract Lifetimes of 10 Ta II levels have been determined using selective pulsed laser excitation and time resolved observation of the reemitted fluorescence. The ions were produced in a low pressure hollow cathode discharge.

Radiative lifetimes of argon II and krypton II levels

Radiative lifetimes of eleven argon II and krypton II levels have been determined using selective pulsed laser excitation and time resolved observation of the reemitted fluorescence. The laser excitation was performed from metastable Ar II and Kr II levels, populated by a pulsed low pressure hollow cathode discharge. The results are discussed with regard to trends in the behaviour of lifetimes along homologous series.

Study of the pressure broadening of the 587.6 nm helium and the 588.2 neon lines

Laser polarisation spectroscopy has been used to measure broadening and shift of the helium 587.6 nm and the neon 588.2 nm lines in a low-pressure glow discharge. A least-squares computer routine accounting for competing broadening contributions extracted the pressure broadening parameters from the raw data. The results are compared with those of Cahuzac and Damaschini (1977), (1980) for the helium line and with those of Kuhn and Lewis (1967) and Jabr and Bennett (1980) for the neon line.

Pressure broadening of the calcium 657.3 nm line by helium, neon and argon

Doppler-free laser spectroscopy has been used to measure the broadening of the 657.3 nm calcium intercombination line by the noble gases helium, neon and argon. A multiparameter least-squares fit was used to deduce the pressure broadening parameters from the raw data. To clarify the shape of the Doppler-free line, core deviations from a simple Voigt profile were taken into account. For this purpose the Zeeman splitting of the 657.3 nm calcium line due to small magnetic fields was determined. The results for the broadening parameters are compared with those of Smith (1967) who applied classical spectroscopy to the same broadening phenomena.

Radiative lifetimes of Fe II levels

Radiative lifetimes for fourteen levels of the z 6Do, z 6Fo and z 6Po Fe II terms have been measured by the technique of laser-induced fluorescence from sputtered metal vapour extracted from a pulsed hollow cathode. The states under investigation were populated from the ground state with UV dye laser pulses down to 234 nm.

Lifetime measurements of the Kr III 5p 5P3 level using time-resolved laser-induced fluorescence spectroscopy

Abstract The radiative lifetime of the Kr III 5p 5P3 level has been measured by the technique of time-resolved laser-induced fluorescence and a novel ion source. In a first step doubly charged krypton ions are prepared by the combination of a pulsed electron beam and a pulsed hollow cathode discharge. In a second step the selective excitation of the level under investigation is performed with subnanosecond laser pulses from a frequency stabilized distributed-feedback dye laser system. A lifetime of τ=5.7 (3) ns is found for the 5p 5P3 level.