Characterizing exact energy density distributions for laser-accelerated ion bunches in a medium is challenging due to very high beam intensities and the electro-magnetic pulse emitted in the laser–plasma interaction. Ion-bunch energy acoustic tracing allows for reconstructing the spatial energy density from the ionoacoustic wave generated upon impact in water. We have extended this approach to tracing ionoacoustic modulations of broad energy distributions by introducing thin foils in the water reservoir to shape the acoustic waves at distinct points along the depth–dose curve. Here, we present first simulation studies of this new detector and reconstruction approach, which provides an online read-out of the deposited energy with depth within the centimeter range behind the ion source of state-of-the-art laser–plasma-based accelerators.

The high energy loss of heavy ions in matter as well as the small angular scattering makes heavy ion beams an excellent tool to produce almost cylindrical and homogeneously excited volumes in matter. This aspect can be used to pump short wavelength lasers. For the first time, a beam of heavy ions was used to pump a short wavelength gas laser in an experiment performed at the GSI ion accelerator facility in December 2005. In this experiment, the well-known KrF* excimer laser was pumped with an intense uranium beam. Pulses of an uranium beam compressed down to 110 ns (full width at half maximum) with initial particle energy of 250 MeV per nucleon were stopped inside a gas laser cell. A mixture of an excimer laser premix gas (95.5%Kr + 0.5%F2) and a buffer gas (Ar) in different proportions was used as the laser gas. The maximum beam intensity reached in the experiment was 2.5 × 109 particles per pulse, which resulted in 34 J/g specific energy deposited in the laser gas. The laser effect on the transition at λ = 248 nm has been successfully demonstrated by various independent methods. There, the laser threshold was reached with a beam intensity of 1.2 × 109 particles per pulse, and the energy of the laser pulse of about 2 mJ was measured for an ion beam intensity of 2 × 109 particles per pulse. As a next step, it is planned to reduce the laser wavelength down to the vacuum ultraviolet spectral region, and to proceed to the excimer lasers of the pure rare gases. The perspectives for such experiments are discussed and the detailed estimations for Xe and Kr cases are given. We believe that the use of heavy ion beams as a pumping source may lead to new pumping schemes on the higher lying level transitions and considerably shorter wavelengths, which rely on the high cross sections for multiple ionization of the target species.

Electron beams with a particle energy of typically 12 keV are used for collisional excitation of dense gases. The electrons are sent through ceramic membranes of only 300 nm thickness into gas targets. Excimer light emission from the pure rare gases and from gas mixtures are studied for the development of brilliant VUV and UV light sources. The application of the technology for gas kinetic studies is described and its potential for building very small electron beam pumped lasers is discussed.

The emission of the third continuum of argon in the wavelength range between 175 and 250 nm and the vacuum ultraviolet emission of neon (λ < 100 nm) has been studied by timeresolved optical spectroscopy. The target gases at pressures between 2 and 100 kPa were excited with a pulsed beam of 100 MeV 32S9+ ions from the Munich Tandem van de Graaf accelerator. Wavelength spectra recorded in different time windows after the 2-ns beam pulses show that two different components contribute to the third continuum of argon. A radiative lifetime of 5.71 ± 0.08 ns for the Ar22+ molecule and a rate coefficient k3 = (1.46 ± 0.12) x 10-30 cm6/s for the reaction Ar2+ + 2Ar → Ar22+ + Ar were obtained from the pressure dependence of time spectra at a wavelength of 190 nm. From time- and pressure-dependent studies of the third continuum emission of neon at a wavelength of 99 nm, rate coefficients k2 = (3.6 ± 0.3) x 10-13 cm3/s for the bimolecular reaction Ne2+ + Ne→ 2Ne+ and k3 = (2.84 ± 0.09) X 10-31 cm6/s for the termolecular reaction Ne2+ + 2Ne → Ne22+ + Ne were determined.

The possibility of heavy-ion beam-pumped ion lasers is demonstrated by observation of optical gain on the 476.5-nm Ar II 4p–4s ion laser transition in argon gas excited by 2.5–ns pulses of 110–MeV 32S ions with repetition rates up to 156 kHz. The particle energy per pulse was about 20 μJ. The projectiles were stopped in the target at pressures between 5 and 35 kPa. The beam from an argon ion probe laser operated at 476.5 nm was used to determine gain amplitude and time structure from a measured transient increase of the probe laser intensity when target excitation by the ion beam was present. The maximum gain observed was (0.5 ± 0.1) x 10-3 at a target gas pressure of 5 kPa. The optical gain observed in argon is consistent with calculations based upon an analysis of spectroscopic studies of rare gas targets excited by heavy-ion beams.

Heavy-ion accelerators can provide various beams from protons to uranium ions with energies ranging from a few keV/u to more than 1 GeV/u. The Munich Tandem van de Graaff accelerator has been used for most of the experiments described in this article. It can provide continuous or pulsed beams of almost all elements with particle energies of about 3.5 MeV/u. The pulse width is typically 2 ns. Maximum DC-beam currents of the order of 10 μA can be obtained, for example, for 32S ions. When the beam is focused to a beam spot of about 3 mm diameter, the flux of the ions is comparable to the flux of fission fragments used for nuclear-pumped lasers. Ion beam pumping is therefore well suited for model experiments of nuclear-pumped lasers. Technical aspects of ion beam-pumped lasers are discussed and the results of the lasers that have thus far been pumped by this method aresummarized. As ion beams are available either continuous or at high-pulse repetition rates ranging from tens of kHz to MHz, detailed spectroscopic and time-resolved studies of the emission of light induced by heavy-ion excitation of the target material can easily be performed. Experiments in which the emission by rare gas excimers and line radiation from atoms and ions has been studied are described. Lifetime measurements of excited levels at different target densities were used to measure collisional rate constants.

General aspects of the excitation of matter with heavy-ion beams are discussed. Lasers in the wavelength region between 1 and 3 μm in rare-gas mixtures pumped with 1.9-GeV xenon, 100-MeV sulphur, 3.6-MeV argon, and 3.3-MeV helium ions are described as examples for lasers pumped by heavy-ion beams. The beam power ranges from a few watts (dc) to about 1 MW during short pulses of about 1-ns length. Optical gain can be measured with an intracavity method. Data on the shape of the volume excited by a 100- MeV 32S beam are shown. An experimental setup for time-resolved optical spectroscopy in a wide wavelength region between a few nanometers and about 700 nm is described. Emission spectra of rare gases excited by heavy-ion beams are discussed and optical gain on ion lines and excimer bands is estimated for different target and beam parameters. Collisional processes in the target gas were studied by time-resolved optical spectroscopy. Population densities of selected 3p levels in Ne I, II, and IV and rate constants for collisional depopulation of excited levels were determined. Experiments planned at the heavy-ion synchrotron SIS at Gesellschaft für Schwerionenforschung in Darmstadt are discussed.

The article presents the results of the experimental research on precision measurement of total stopping range and energy deposition function of intermediate and heavy ion beams in cold solid matter. The “thick target” method proves to be appropriate for this purpose. Two types of detectors were developed which provide an error of the total stopping range measurement of less than 3% and of the beam energy deposition function of about 7%. The experiments with 58Ni+26, 197Au+65, and 238U+72 ion beams in the energy range 100–300 MeV/u were performed on SIS-18 (Gesellschaft für Schwerionenforschung, Darmstadt) in 1999–2001. The measured data on the total stopping ranges for the above ion species in bulk and foiled Al and Cu targets are presented. The investigation showed that there is a noticeable discrepancy between the measured stopping ranges and the theoretically predicted ones. Also, it was shown that realistic ion energy deposition depends on the type of target (bulk or foiled). Further investigation is necessary to clarify the latter.

Correlations of Doppler shifted line shapes with time-of-flight spectra of fast ions has been established for nanosecond-laser pulses. Fast ion energies of different velocity groups have been established in the large interval of Iλ2 = 4 × 1012–5 × 1016 W/cm2 μm2. The obtained scaling relations differ markedly from those reported by Gitomer et al. (1996).

By the interaction of intense (1010 particles/500 ns) relativistic (∼300 MeV/amu) heavy ion beams with solid targets, large volumes (several cubic millimeters) of strongly coupled plasmas are produced at solid-state densities and temperatures of up to 1 eV, with relevance for equation-of-state (EOS) studies of matter at high energy density and heavy ion-beam-driven inertial confinement fusion (ICF). The time and space profile of the ion beams, focused by the plasma lens to diameters of a minimum of 0.5 mm in order to obtain specific energy depositions of up to about 4 kJ/g, were measured to calculate the energy deposition in the target. In the present work, the plasmas created by ion beam interaction with cryogenic gas crystals and metallic targets are studied, among other methods, by backlighting shadowgraphy and electrical conductivity measurements. The experiments are coupled with two-dimensional hydrodynamic simulations.

This paper presents two-dimensional numerical simulations of heating of matter with intense heavy ion beams. It has been shown that it is very advantageous to irradiate the target with two different beams simultaneously, a main high intensity bunched beam of a heavy element like uranium and an unbunched low intensity beam of a lighter element like argon. The main beam is used to heat the target while the second beam is used as a diagnostic tool.

Influence of the shape of the focal spot on compression and heating of matter has also been studied using an elliptic focal spot with an ellipticity of 1.5 (semimajor axis is along y-axis and is 1.5 times the semiminor axis which is along x-axis). It has been found that the temporal behavior of the development of density, pressure, and temperature profiles along different directions is quite different, which is not the case with a circular focal spot.

At the Gesellschaft für Schwerionenforschung (GSI, Darmstadt) intense beams of energetic heavy ions have been used to generate high-energy-density (HED) state in matter by impact on solid targets. Recently, we have developed a new method by which we use the same heavy ion beam that heats the target to provide information about the physical state of the interior of the target (Varentsov et al., 2001). This is accomplished by measuring the energy loss dynamics (ELD) of the beam emerging from the back surface of the target. For this purpose, a new time-resolving energy loss spectrometer (scintillating Bragg-peak (SBP) spectrometer) has been developed. In our experiments we have measured energy loss dynamics of intense beams of 238U, 86Kr, 40Ar, and 18O ions during the interaction with solid rare-gas targets, such as solid Ne and solid Xe. We observed continuous reduction in the energy loss during the interaction time due to rapid hydrodynamic response of the ion-beam-heated target matter. These are the first measurements of this kind. Two-dimensional hydrodynamic simulations were carried out using the beam and target parameters of the experiments. The conducted research has established that the ELD measurement technique is an excellent diagnostic method for HED matter. It specifically allows for direct and quantitative comparison with the results of hydrodynamic simulations, providing experimental data for verification of computer codes and underlying theoretical models. The ELD measurements will be used as a standard diagnostics in the future experiments on investigation of the HED matter induced by intense heavy ion beams, such as the HI-HEX (Heavy Ion Heating and EXpansion) EOS studies (Hoffmann et al., 2002).

The experimental results of the activation spectra, dose rate measurements, and the residual nuclide production cross sections obtained after the irradiation of the NatCu and 59Co targets by 12C ion beams at ITEP and GSI are presented in this paper. These results are compared with simulations by the CASCADE and LAQGSM codes.

The X-ray spectral distribution of swift heavy Ti and Ni ions (11 MeV/u) observed inside aerogels (ρ = 0.1 g/cm3) and dense solids (quartz, ρ = 2.23 g/cm3) indicates a strong presence of simultaneous 3–5 charge states with one K-hole. We show that the theoretical analysis can be split into two tasks: first, the treatment of complex autoionizing states together with the originating spectral distribution, and, second, a charge-state distribution model. Involving the generalized line profile function theory, we discuss attempts to couple charge-state distributions.

A buried (Fe1−xCox) Si2 (x < 0.2) layer was formed by two step high dose implantation of Fe and Co into {100}-Si with as well as without intermediate annealing between the implantations. The suicide layer remains semiconducting if the temperature of the post implantation annealing is lower than 850°C. The depth distribution of Fe and Co, the phase composition as well as the microstructure of the layer system was investigated.