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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.

Atomic thorium ions were stored in an r.f. quadrupole trap and excited by tunable laser light. One-step and two-step excitation schemes were applied; a four to eightfold reduction of the Doppler linewidth is obtained for the two-step scheme with essentially no loss in signal strength. The Doppler-free two-photon transition was also observed. The lineshapes were calculated using a simple model; the observed profiles were well reproduced proving that the velocity and acceleration features of stored ions are properly accounted for. A further reduction of the Doppler linewidth is expected for the two-step method if a short lived intermediate level is used.

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.

The Karlsruhe Light Ion Facility KALIF generates proton pulses of typically 50 ns duration with proton energies up to 1.7 MeV and currents between 0.2 and 0.4 MA. The protons are focussed on thin aluminum foils thus generating specific energy densities of a few MJ/g, pressures of up to 60 GPa and temperatures of about 20 eV in the targets. Time resolved velocity measurements are used to study the hydrodynamic response of ablatively accelerated foils, and plasma temperatures are determined from K/sub /spl alpha// emission spectroscopy. We compare radiation hydrodynamic models and synthetic K/sub /spl alpha// spectra with the measurements in order to deduce details about the beam history of the KALIF diodes.

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.

In the course of preparing experiments with178m2Hf, optical isotope shifts for the stable Hf isotopes and for172Hf were measured. For the rms nuclear charge radii we obtain 〈r2〉172 -(r2)178=−0.242(16) fm2.

Isotope shifts and hyperfine splittings in optical transitions for atomic ions of the thorium isotopes227Th to230Th and232Th have been measured by laser spectroscopy on stored ions. From the isotope shift data, changes of the mean square charge radii are determined. A continuous increase of the charge radius with mass numberA is observed, in agreement with droplet model calculations. The results indicate that the odd-even staggering for Th is different from that one of the neighbouring isotones of Fr and Ra. There is some empirical evidence from systematics for an inversion of the staggering and the appearance of an octupole deformation atN ≦137. The hyperfine splitting for229Th for 3 electronic levels is given.

The isotope shifts and hyperfine splittings for 11 strontium isotopes (A=80–90) and two isomers for the optical transition λ=293.2 nm were measured. The magnetic dipole and electric quadrupole moments and the changes of the mean square charge radii are derived. The results are discussed with respect to the increasing nuclear deformation and the anomalous coupling scheme of light Sr nuclei.

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 .

The Doppler-free two-photon absorption method performed with a narrowbandc w dye laser permitted high resolution measurements of transitions from the Ba I ground state 6s 2 1 S 0 to several highly excited states. The lifetimes and hyperfine splittings of these states as well as the isotope shifts of the transitions have been determined accurately. The lifetime values are in agreement with transition probability data; the hyperfine splitting results show considerable configuration interaction effects. A detailed discussion of the isotope shifts is given.

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) .

Previous laser-spectroscopic studies of the hyperfine structure splittings and isotope shifts of the (6p 2 3 P 0 -6p7s 3 P 1 ; 283.3 nm) PbI resonance line have been extended to further radioactive Pb nuclides: 196, 197, 197m, 211, 214 Pb Using an improved theoretical result for the specific mass shift, we recalibrate the isotope shifts of the full series ( A = 196–214) of measured isotope shifts in terms of the nuclear parameter and determine the odd-even staggering parameters. The variation of the nuclear charge radii of the Pb nuclides exhibits distinct shell effects, and the odd-even staggering shows a conspicuous trend, being more pronounced for neutron-deficient Pb isotopes.

Theg J factors of the metastable states3 P 2 of88Sr and3 D 1,3 D 2,3 D 3, and1 D 2 of138Ba have been measured using the atomic-beam magnetic resonance method. The metastable states were populated by an electric discharge within the atomic-beam source. From the measurements of rf transitions between the Zeeman levels (m J =+1)↔(m J =−1) we obtained:88Sr:g J (3 P 2) =1.501124(10)138Ba:g J (3 D 3)=1.3340823 (10)g J (3 D′2)=1.1637406(11)g J (3 D 1)=0.4985751(13)g J (1 D′2)=1.003 1449(10). The relativistic and diamagnetic corrections for theg J factor of the3 P 2 state of Sr have been calculated. With these and the Schwinger correction included we getg J (3 P 2)=1.501119(12).

We have observed the optically forbidden 3s-4d transition in sodium vapor, using two-photon excitation with a cw dye laser and monitoring the 4d population via fluorescence cascades. High resolution spectra without Doppler broadening and line widths of less than 30 MHz were obtained with two counter-propagating laser beams, whose Doppler shifts cancel. We have measured the 4d fine structure splitting to be 1035 ± 10 MHz.

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 .

The hyperfine structure of Am atoms was investigated in an atomic beam by laser spectroscopy. The observed splittings were evaluated with respect to the magnetic dipole and electric quadrupole moments of242mAm. The results are: μ I (242mAm)=+0.97(5)nm,Q(242mAm)=+6.5(2.0)b.

The electronic transitions from the ground state to the 3d states have been studied for23Na and7Li atoms by two-photon Doppler-free laser spectroscopy. The positions of the resonances are used to determine the unresolved hyperfine structure of the 3d states from which the magnetic-dipole hyperfine interaction constantsA are derived. The results for theA factors are:A(3d 2 D 3/2;23Na)=+527(25) kHz;A(3d 2 D 5/2;23Na)=+108.5(2.4) kHz;A(3d 2 D 3/2;7Li)=+843(41) kHz;A(3d 2 D 5/2;7Li)=+343.6(1.0) kHz. For the fine structure intervals fs of the 3d doublets we obtain: fs(3d Na)=-1 494 444(44) kHz and fs(3d Li)=+1 083 936(60) kHz. The linewidths of the resonances are evaluated with respect to the natural lifetimes of the 3d states. For Na the result is τ(3d Na)=19.27(23) ns.

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.

The hyperfine structure of the four lowest levels5F5, 4, 3, 2 of the5F ground state multiplet arising from the configuration 4d7 5s in99Ru and101Ru has been studied by the atomic — beam magnetic — resonance technique. After applying corrections due to the effects of off-diagonal hyperfine mixing we obtain the following multipole interaction constants:99Ru:A(5F5)=−204.5514(33) MHzB(5F5)=27.281 (62) MHzA5F4=−163.6845(36) MHzB(5F4)=17.455(52) MHzA5F3=−135.0294(37) MHzB(5F3)=10.164(50) MHzA(5F2)=− 82.5325(27) MHzB(5F2)=5.457(22) MHz101Ru:A(5F5)=−229.2881(33) MHzB(5F5)=158.934(62) MHzA(5F4)=−183.4744(36) MHzB(5F4)=101.799(52) MHzA(5F3)=−151.3502(38) MHzB(5F3)=59.323(50) MHzA(5F2)=−92.4974(27) MHzB(5F2)=31.869(23) MHz. The magnetic dipole and the electric quadrupole moments of the99Ru and101Ru nuclear ground states as calculated from these constants are the following:μI(99Ru)=−0.594(119) nmQ(99Ru)=0.077 (15) barnsμI(101Ru)=−0.666(133)nmQ(101Ru)=0.45 (9) barns. From measurements of the Zeeman effect in the even isotope102Ru we find the followinggJ-factors for the5F ground multiplet:gJ(5F5)=1.397741(20)gJ(5F4)=1.347604(20)gJ(5F3)=1.248988(20)gJ(5F2)=1.001120(3).

Fourteen transitions in ReI, starting from high-lying metastable states belonging to the configurations (5d+6s)7, have been studied by laser-induced fluorescence in a collimated atomic beam, and accurate values for the isotope shifts in these transitions as well as for the hyperfine structure constants of 13 metastable and 9 excited states have been obtained. In addition, high precision measurements of the hyperfine structure of the states 5d5 6s24D7/2 and 5d6 6s6D1/2, 3/2, 5/2, 9/2 have been performed using the atomic beam magnetic resonance technique coupled with laser-induced state-selective detection of metastable atoms. The analysis of the hyperfine structure data yields experimental evidence for far configuration mixing effects on the off-diagonal spin-dipole matrix elements. The phenomenological interpretation of the isotope shifts shows the significance of off-diagonal field-shift effects.

The hyperfine structure constants and the electronic g J factor of the state 4f 11 6s 2 4 I 11/2 belonging to the holmium ground multiplet have been measured using the atomic beam magnetic resonance technique combined with a state-selective laser-induced detection of the resonant atoms. By the same method the g J factor of the level 4f 116s 24 I 9/2 was determined, while the hyperfine structures of this metastable state and of two high-lying even parity states have been investigated by high resolution laser spectroscopy. The results for the experimentalA andB factors of all four members of the ground multiplet allow a least-squares evaluation of the three magnetic dipole and the three electric quadrupole effective radial parameters for the configuration 4f 11 6s 2 of holmium, yielding an accurate value for the spectroscopic nuclear electric quadrupole moment:Q hfs(165Ho)=2.716(9)b (uncorrected for quadrupole shielding). From a comparison to the quadrupole moments measured in mesic holmium atoms the shielding factor could be estimated.

The experimental data on the hyperfine structure of93Nb are analysed with respect to the effective-operator formalism. Using eigenvectors derived from a least squares fit to the excitation energies of all known levels of the configurations 4d 4 5s and 4d 35s 2 the effective radial parameters of the magnetic dipole and electric quadrupole interaction are determined. The comparison with relativistic calculations gives an estimate of the effects due to configuration interaction. The value found for the nuclear electric quadrupole moment isQ=−0.36(7) barns.

To determine the accuracy to which hyperfine splittings can be measured using a cw dye laser with rf sideband tuning, a series of atomic beam experiments with59Co was performed. One hyperfine splitting of the first excited metastable atomic state was measured and compared with the results for the same splitting from magnetic rf resonance experiments. The uncertainty with the methods applied was found to be about 0.05 to 1% of the experimental linewidth in general; it is ±20 kHz or ±0.05% of the linewidth in the present Co experiment. The hyperfine splitting constants of the 3d 8 4p 2 F 7/2 state were found to beA=419.3(9) MHz,B=−77(17) MHz.

The hyperfine structure of the ground state 4d5 5s7S3 of95Mo and97Mo has been measured by the atomic beam magnetic resonance technique with the following results:95Mo:A=−208.582060(10)MHz,B=37.050 (100) kHzC=−30 (10) Hz,D=−3 (3) Hz97Mo:A=− 212.980930 (10) MHz,B−69.990(140)kHzC=−5 (10) Hz,D=0 (3) Hz. After application of corrections calculated according to second order perturbation theory, the hyperfine structure constants became:95Mo: Ac=−208.582560(290)MHz,B c =16.920(4300)kHzCc=−30(270) Hz,D c =− 3 (50) Hz97Mo: Ac=212.981450(300) MHz,B c =−90.780(4400)kHzCc=−6(270) Hz,D c =0 (50) Hz. With the known ratio ofgI(95Mo)/gI(97Mo) [1] a calculation of the hyperfine anomaly yields:95Δ97=−0.01009(17)%.

The 5d 26s 2 3 F 2 ground state of177Hf,179Hf and180Hf has been studied using the atomic beam magnetic resonance method. The atomic beam was produced by an universal evaporation technique described in a previous paper. The results are180Hfg j (3 F 2)=0.695812 (10)177Hf Δv(3 F 2;F=11/2↔F=9/2)=991.7917 (10) MHz Δv(3 F 2;F=9/2↔F=7/2)=477.0081 (10) MHz Δv(3 F 2;F=7/2↔F=5/2)=162.8890 (10) MHz179HfΔv(3 F 2;F=13/2↔F=11/2)=82.1320 (10) MHz Δv(3 F 2;F=11/2↔F=9/2)=392.8498 (10) MHz. The magnetic dipole and electric quadrupole moments of the177Hf and179Hf nuclear ground states as calculated from these hyperfine structure measurements are the following: μ(177)=0.75(8)μ k , Q(177)=4.34 (65) barns μ(179)=−0.61 (6)μ k , Q(179)=4.90 (75) barns.

The5d76s24F9/2 atomic ground state of191Ir and193Ir has been studied using the atomic-beam magnetic-resonance method. The results are:193Ir:gJ(4F9/2)=1.29694 (3)191Ir:Δv(4F9/2; F=6↔F=5)=659.26496 (12) MHzΔv(4F9/2; F=5↔F=4)=189.44002 (09) MHzΔv(4F9/2; F=3↔F=4)=84.05040 (80) MHzA=57.52148 (04) MHzB=471.20425 (57) MHzC=−0.020 (30) kHz193Ir:Δv(4F9/2; F=6↔F=5)=660.09043 (12) MHzΔv(4F9/2; F=5↔F=4)=224.47848 (13) MHzΔv(4F9/2; F=↔F=4)=33.53453 (89) MHzA=62.65556 (05) MHzB=426.23546 (64) MHzC=0.020 (30) kHz Using the magnetic dipole moments known by NMR-technique [1] we obtained for the electric quadrupole moments as calculated from the hyperfine interaction constantsA andB:Q(191Ir)=0.78 (20) barns,Q(193Ir)=0.70 (18) barns (uncorrected for core polarization effects). A calculation of the hyperfine anomaly yields:191Δ193=−0.00023 (10). The ratio of theB factors which should be the same as for the quadrupole moments turned out to be:B(191Ir)/B(193Ir)=Q(191Ir)/Q(193Ir)=1.105502(3).

Applying a recently developed evaporation technique for refractory elements the following results have been obtained for Ta181 in an atomic beam magnetic resonance experiment studying the hyperfine structure of 3 levels of the ground state multiplet4F: $$\begin{gathered} g_J (^4 F_{3/2} ) = 0.45024 (4) \hfill \\ \Delta v (^4 F_{3/2} ;F = 5 \leftrightarrow F = 4) = 1822.389 (6) MHz \hfill \\ \Delta v (^4 F_{3/2} ;F = 4 \leftrightarrow F = 3) = 2325.537 (2) MHz \hfill \\ \Delta v (^4 F_{5/2} ;F = 6 \leftrightarrow F = 5) = 1451.476 (7) MHz \hfill \\ \Delta v (^4 F_{5/2} ;F = 5 \leftrightarrow F = 4) = 1537.530 (8) MHz \hfill \\ \Delta v (^4 F_{5/2} ;F = 4 \leftrightarrow F = 3) = 1444.685 (2) MHz \hfill \\ \Delta v (^4 F_{7/2} ;F = 4 \leftrightarrow F = 3) = 1218.372 (2) MHz. \hfill \\ \end{gathered}$$

Using the atomic beam magnetic resonance method the experimental hyperfine structure data of the 5d26s23F2 ground state of177Hf and179Hf described in a previous paper [1] have been completed. After applying corrections due to perturbations by other fine structure levels of the configuration 5d26s2 we got the following multipole interaction constants: $$\begin{gathered} ^{177} Hf:A = 113.43314 (7) MHz B = 624.3293 (13) MHz \hfill \\ C = 0.27 (18) KHz D = 0.045 (40) KHz \hfill \\ ^{179} Hf: A = - 71.42891 (9) MHz B = 705.5181 (24) MHz \hfill \\ C = - 0.43 (20) MHz D = 0.07 (6) KHz. \hfill \\ \end{gathered} $$ By measuring rf transitions at magnetic fields between 1100 and 1550 Gauss the nuclear ground state magnetic dipole moments were determined. The results are: $$\mu _I (^{177} Hf) = 0.7836 (6) \mu _N , \mu _I (^{179} Hf) = - 0.6329 (13) \mu _N $$ (uncorrected for diamagnetic shielding).

A new universal method for the production of atomic beams of highly refractory elements has been developed. The beams of free atoms are produced by locally heating a small area on a target consisting of the material to be evaporated. The local heating is achieved via the focussed electron beam of a commercial electron gun. The atomic beams so obtained are suitable for studying hyperfine structures by the atomic beam magnetic resonance method. The first observedrf resonances in the ground state4F3/2 and the first excited state4F5/2 of Ta181 are reported.

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.

The hyperfine structure of an atomic transition in 180 Ta was investigated by laser-induced resonance fluorescence. As a result we obtained for the quantity μ I 180 (1+ 1 2 I 180 ) the value 5.04 (5) μ N . This experimental result is best reproduced assuming parallel coupling of a 9 2 − [514] proton and a 9 2 + [624] neutron. It is concluded that 180 Ta most likely has I π =9 − and a magnetic dipole moment μ I =4.77 (5) μ N .

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 a cw dye laser the 3d24s4F 5 2 , 7 2 metastable levels of 45Sc were populated by optical pumping. The second order corrected hyperfine constants are: A( 5 2 ) = 154.035 (2) MHHz , B( 5 2 ) = -6.45(4) MHz , A( 7 2 ) = 250.012(2) MHz , ( 7 2 ) = -9.07(4) MHz .

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 .

We give data of the isotope shift for the strontium isotopes from A=80 to A=90. They are found to be inconsistent with data from another optical transition. Possible reasons for the discrepancy are discussed.

The nuclear ground-state magnetic dipole moments of 177Hf and 179Hf have been determined with the atomic beam magnetic resonance method. The results are: μ I ( 177 Hf = 0.7836(6)μ N , μ I ( 179 Hf) = −0.6329(13) μ N (uncorrected for diamagnetic shielding).