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The Karlsruhe Light Ion Facility (“KALIF”) enables us to heat material by proton impact. For solid targets in the proton focus we reach a specific energy deposition between 1 and 10 MJ/g resulting in a hot and dense plasma. To study the plasma development we exploit the satellite structure of the K α soft X-rays emitted or absorbed by the plasma produced by subrange targets. The experimental results are compared with corresponding calculations. Time-integrated K α emission spectra have been observed for Al and Si. They show that the peak kT in the target plasma can be above 20 eV. The spectra also give some clue as to the beam intensity of each individual KALIF shot. For K α absorption spectroscopy a Nd : YAG laser system was installed. It is used to provide soft X-ray backlighter radiation from a laser induced plasma. Different elements were studied as laser targets to cover the K α absorption features of the elements around Al. We found the M transition group of the rare earth elements useful with respect to the wavelengths needed.

A miniature hydrogen laser working on the H 2 (B) → H 2 (X) transition at 161 nm is described. A fast spark gap realized by distilled water as the dielectric accomplished the necessary fast pumping circuitry. The simple device operates with a charging voltage of less than 9 kV at pressures up to 1500 hPa and yields pulses of 1 μJ with a width of less than 500 ps . The increase of the operating pressure above 1000 hPa leads to only a moderate increase in the output energy. Measurements of the fluorescence yield show that the quenching rate of H 2 (B) by hydrogen is k =(1.8±0.2)×10 −9 cm 3 /s . A kinetical model that reproduces the observed properties is proposed.

Filament formation in the discharge deteriorates the properties of lasers operated at high gas pressures. In the present investigation, a semiconductor electrode was used to suppress the filamentation in a nitrogen laser run at atmospheric pressure. A considerable improvement of the laser performance mainly concerning the pulse fluctuations was obtained. By miniaturization of the laser, the usually applied plasma switch was replaced by a semiconductor switch.

In this paper we describe the development of a novel high‐resolution line‐imaging laser‐Doppler velocimeter to investigate the hydrodynamic response of planar solid targets to the irradiation with intense light ion beams. It is demonstrated that a detailed analysis of the target velocity history can be used to derive equation of state data and to determine ion ranges in hot dense plasmas. To measure the central temperature in sub‐range targets a Kα‐absorption spectrometer is presented which uses a laser produced backlighter in the soft x‐ray regime to transmit radiation through the ion beam heated target.

Dysprosium atoms were isotope selectively excited by cw dye laser light. They were ionized by charge transfer collisions with Cs + ions. The process was found to discriminate well between ground state and excited state atoms. The cross section ration for the two competing processes was determined to be about 10 3 .

Using a cw dye laser for detecting rf resonances in metastable Mo levels, their hyperfine B factors were determined. This resulted in Q( 95 Mo )=−0.015(4)b , Q( 97 Mo )=+0.17(4)b and Q( 97 Mo ) Q( 95 Mo ) =−11.50(3) .

Precision tuning of a narrow-band cw dye laser allows to determine effects that normally are masked by the natural width of short-lived atomic states. With the 15 kHz accuracy of our laser system we were able to detect small frequency shifts between the components of the 3 s → 4 d two-photon transition of sodium which are due to the 4d hyperfine splitting. The A -factors of the 23 Na 4d states were determined: A( 2 D 3 2 ) = + 215 (15) kHz , A( 2 D 5 2 ) = + 29 (6) kHz .

For frequency stabilization of a cw dye laser a very fast reacting piezo mirror translator with 350 kHz lowest resonance frequency has been developed. If it is driven by appropriate control electronics it allows to suppress efficiently fast frequency changes of the jet stream dye laser. The remaining frequency jitter is 270 kHz rms for full-bandwidth detection; it drops to a few kHz if a filter time constant of 100 μs is used.

Systematic studies of the optical isotope shift and the hyperfine splitting of long chains of stable and radioactive isotopes were performed. The method applied was laser induced resonance absorption; the experimental techniques were the atomic beam method with fluorescence detection and the optogalvanic method. The theory of hyperfine splitting and isotope shift of atoms is reviewed in short with emphasis on the aspects interesting for nuclear physics and on the evaluation problem. The experimental methods are described and their key parameters sensitivity and resolution are discussed. Preliminary results on stored thorium ions are given. Sample results for the nuclear quantity δ derived from atomic beam experiments with tin and strontium are presented.

Millimeter‐wave GaAs Schottky barrier diodes were used as fast light detectors. It was possible to observe beat signals between a HeNe laser oscillating at 633 nm and a cw dye laser with approximately 80‐GHz frequency offset. Thus, great frequency differences between lasers emitting in the visible can be determined with the high accuracy inherent in heterodyning techniques.

The basic properties of a two-step laser isotope enrichment process which uses charge transfer ionization as second step have been investigated. It was studied using Eu atoms and protons. The cross section ratio for ionization from the excited state and from the ground state which is relevant for the selectivity has been determined to be about 40.

For investigations of fine details of atomic energy spectra light sources are requiredwhich emit light with very well defined frequency. A powerful tunable light source is thecw dye laser. Since the frequency of a free- running laser jitters, it has to be stabilized.In order to avoid the high internal losses of a stabilization system with an intracavi-ty electrooptic crystal, a very fast piezoelectric mirror translator has been developed.It was driven by properly designed electronics. Thus a small laser frequency bandwidth of270 kHz rms with an output power of up to 200 mW was obtained. The laser system was testedin a sub -natural linewidth two -photon experiment with Na atoms.IntroductionWithin the different types of light sources the continuous -wave dye laser exhibitsseveral unmatched features: well collimated light beam, high output power, easy tunabilityand very narrow frequency bandwidth if operated in the single- frequency mode. Thus it isalmost an ideal tool for investigating the energy spectra of atoms and molecules. Severalmodels are nowadays commercially available with a typical frequency stablity of the free -running laser of 5 MHz rms, corresponding to a relative stability of 1:10

We report laser spectroscopic measurements of isotope shifts and hyperfine structure in ten stable and unstable lead isotopes, including two not previously measured.

Using the method of atomic-beam magnetic resonance, detected by laser-induced resonance fluorescence (ABMR-LIRF), the atomic ground-state hyperfine intervals of 50V were precisely measured. A quadrupole moment ratio Q( 50 V ) / ( 51 V = −4.03(3) is obtained which results in Q( 50 V ) = +0.21(4) b .