A review of recent developments in intense ion beam diagnostics used in the international light ion inertial confinement fusion (ICF) programs will be presented. These developments have occurred in each of the several generic classes of diagnostics, namely, imaging diagnostics, particle spectrograph diagnostics, nuclear activation, and visible spectroscopy. Critical beam parameters measured by the new diagnostics include spatial profile, absolute number, species, anode plasma temperature and density, voltage, current density, and power density. A unique feature of most of these diagnostics is that they are capable of operating in hard (multi-MeV) X-ray (bremsstrahlung) backgrounds of some 109–1011 rad/s. The operating principles of each diagnostic will be summarized in the paper with examples of how the diagnostics may be integrated together to form a complete diagnostic system. The paper will close with a discussion of two new data acquisition systems that have been developed for intense beam diagnostics.

This is a short summary of research on the self-magnetically Bθ-insulated ion diode originally proposed by K. Zieher (1981, 1983, 1984, 1984a). We report the most recent progress. For detailed discussions see the forthcoming publications (Schimassek 1989; Westermann 1989). After the exploratory work of Zieher the efforts of recent years have concentrated on the numerical simulation (Westermann 1988; 1988a; 1988b), the development of detailed diagnostic tools (Rogner & Schultheiss 1986; Kühn & Rogner 1985; Klumpp & Bluhm 1986) and the focusing properties of the Bθ-diode (Citron et al. 1986; Bauer et al. 1987; Schimassek et al. 1988; Westermann 1988c). Experiments and numerical simulations on three modifications of the diode will be reported (version I, II, III).

Light ion beams for the energy drive for inertial confinement fusion (ICF) research have been studied on a super high voltage generation system (SHVS) using an inductive voltage adder system. A simple analysis implied the capability of the output voltage of several tens of MV. This system has a feasibility of acceleration of ions heavier than proton. The two-stage charge stripping ion diode is considered a SHVS diode. This diode reduces the size of the induction adder module and extends the possible power range in operation. We have constructed a prototype SHVS, which consists of eight stages of induction cavities (4MV, 40kA, 100ns) powered by a Reiden IV pulse power machine. The first ion diode experiments on the induction adder were performed with the beam extraction type ion diode (Br applied magnetic field). The injection plasma ion source was used to control the diode impedance and then the diode voltage. The time delay of ion current turn-on was reduced from 15–20 ns to less than 5 ns by this ion source.

Beam productions from ammonia ice were tried for the first time to obtain proton beams with reasonable purity under the liquid nitrogen cooling. Beam focusings and neutron productions under the target irradiations were tried with water ice. Resonant and optical interferometries were applied to observe the behavior of neutral particles within the anode-cathode gaps.

Recent progress of pellet implosion research is remarkable in the obtainment of a high density (100 times solid density) and a high temperature plasma (which produces thermonuclear neutrons of 1013 per shot or a pellet gain of 0·2%) and in the corresponding understanding of the implosion physics. The data bases for laser fusion have been accumulated in preparation for a fusion ignition experiment and the achievement of break-even condition, which is estimated to be possible with 100 kJ blue laser.

The recent progress of driver technology, such as new types of solid state lasers, excimer laser, light ion beam (LIB), heavy ion beam (HIB) and free electron laser, now enabled us to design a high pellet gain experiment with a MJ driver.

The LIBRA light ion beam fusion commerical reactor study is a self-consistent conceptual design of a 330 MWe power plant with an accompanying economic analysis. Fusion targets are imploded by 4 MJ shaped pulses of 30 MeV Li ions at a rate of 3 Hz. The target gain is 80, leading to a yield of 320 MJ. The high intensity part of the ion pulse is delivered by 16 diodes through 16 separate z-pinch plasma channels formed in lOO torr of helium with trace amounts of lithium. The blanket is an array of porous flexible silicon carbide tubes with Li17Pb83 flowing downward through them. These tubes (INPORT units) shield the target chamber wall from both neutron damage and the shock overpressure of the target explosion. The target chamber is a right circular cylinder, 8·7 meters in diameter. The target chamber is ‘self-pumped’ by the target explosion generated overpressure into a surge tank partially filled with liquid that surrounds the target chamber. This scheme refreshes the chamber at the desired 3 Hz frequency without excessive pumping demands. The blanket multiplication is 1·2 and the tritium breeding ratio is 1·4. The direct capital cost of LIBRA is estimated to be $2200/kWe.

An overview is given of recent progress in the industrial applications of intense pulse power and associated particle beams, except for activities in inertial confinement fusion. In particular, several topics are discussed which relate to the applications in the R&D of materials, the excitation of short wavelength lasers, the generation of charged particle beams, and the development of plasma X-ray sources.

I. Applications in material processing. If intense pulsed charged particle beams are directed onto materials, only their surfaces where the beam energy is deposited are quickly heated up to very high temperatures. Using the pulsed beam in this way, we might expect to apply them in R&D of materials. Several novel attempts have been made, e.g., on the preparation of thin films by use of a high-density high-temperature plasma, surface modification by surface heating, and ion-beam mixing of multi-layers by use of the focused electron or ion beams, and so on. Furthermore, experimental studies have been done on the surface modification by ion implantation and the evaluation of the damage due to the irradiation by ion beams.

II. Applications in the excitation of short wavelength lasers. Activities in the excitation of high-power, short wavelength lasers by using electron beams or ion beams have increased considerably.

III. Applications in the generation of charged particle beams, and the development of plasma X-ray source. With regard to new accelerator technologies, several attempts are underway on the application of the modified betatron or the development of a convergent electron beam accelerator with a plasma cathode.

Cluster beams may be produced by screening out the core portion of a partially condensed supersonic jet and introducing it into a high vacuum chamber. Potential applications of such beams are reported here and include accelerator targets, plasma generation, nuclear fuel injection into fusion devices, and production of thin layers for microelectronics and optics.

A wide applicaton of high-power braking x-radiation and electron beams is obstructed at present by the absence of compact, screened, inexpensive and reliable generators capable of producing an electron energy of ∼1·5 MeV and a dose rate to objects a few centimeters in size of ∼107 A/kg. This paper presents results from experiments carried out on an X-ray generator with an accelerating voltage of up to 1·8 MV, which meets the above requirements in performance.

The dynamics of the plasma evolution in a dense plasma focus has been studied using a streak camera system in the soft X-ray region. The experiments were performed on a medium energy plasma focus operating with a hydrogen-argon admixture. The streak camera system employed provides nanosecond resolution and allows the plasma to be viewed simultaneously through two different filters to achieve energy resolution. Observations are made in the radial direction and along the pinch axis. Collimated X-ray PIN diodes suitably filtered were used to provide additional information on the structure of the X-ray emitting regions of the plasma. The plasma focus is observed to be totally dynamical and continuously evolving in nanosecond time scale. Hot spots are observed to form among the moving plasma at various times. Such continuous nanosecond time scale evolution of the focus pinch in the X-ray region have not been reported previously.

The simultaneous formation of the two deuterium plasma foci has been reported recently by Hou et al. in a Mather type two-gun plasma focus assembly with maximum bank energy of ∼700 kJ. In addition, these plasmas will evolve and then produce a disk-shaped plasma in the middle of the two plasma foci. Soft X-ray filter techniques which allow measurements of the electron temperature at both pinch points and the middle point yielded a few hundred eV for these three regions. Neutron localization measurements which were carried out with a collimator and a scintillator-fiber-photomultiplier assembly indicate that an enhancement of ∼80% in neutron yield is observed in the middle region as the separation between two electrodes is 9.1cm. Further experimental evidence shows that the neutron production in the middle region is the result of the beam-beam interaction in nature.

We have studied experimentally the relation between the preionization of a plasma micro-channel in Argon at atmospheric pressure and the dynamics of the discharge initiated by preionization. Preionization is obtained in two different ways: (a) injecting the soft X rays produced by a 3 J, 3 ns YAG laser focused on a copper target through a pinhole (b) direct focusing of a 4ω laser (0·26 μm) along the Argon column. Both experiments and simple numerical models are presented in this paper.

Laser induced ablation pressure as a function of absorbed laser intensity for low and moderate atomic number targets has been experimentally determined using a 1·06-μm laser at an irradiance of 5 × 1011 to 1 × 1013 W cm−2. Ablation pressure variations with the absorbed laser intensity indicate a transition from a self-regulating ablation to a deflagration scaling for low atomic targets. The experimental results have also been corroborated with theoretical models and a two dimensional hydrodynamic code.

A two-dimensional hydrodynamic code is discussed. It includes the treatment of energy deposition by heavy ions and the calculation of transport coefficients. Loss terms due to volume radiation in the emission limit and a realistic equation of state (SESAME tables or the equation of state of an ionized gas including the solution of the Saha equations to determine the degree of ionization) are considered.

Numerical simulations are performed to study the hydrodynamic flow in cylindrical tubes filled with the noble gases Argon and Xenon respectively. Target and beam parameters are chosen in close analogy to the GSI-RFQ beam-target experiments.

The conditions for the formation of a shock wave at the interface between matter heated by the ion beam and cold matter are investigated. It turns out that, in addition to ionization effects, shock heating has a strong influence on the maximum target temperature. Depending on the temperatures to be reached with a given deposition power, either expansion or radiation cooling could be the dominant cooling mechanism. As a result we can conclude that hydrodynamic motion produces a lot of structure that should be observable in the GSI experiments.

The emission spectra of HgBr (B–X) band system and atomic mercury lines have been observed during collisions involving O+/ and HgBr2 in the kinetic energy (lab.) range of 100–1000 eV.

We have completed the conceptual design of a 170-MJ laser system consisting of two identical, opposing, 0·4 M-litre, 84-MJ HF subsystems, which together deliver 105 ‘useful’ MJ in 50 ns (FWHM duration) to a laser-fusion target during its hydrodynamic drive interval. We achieved extreme design simplicity by eliminating most optics, using an inexpensive, very-high-energy-density gain medium, propagating the laser beam at the maximum fluence permitted by optical breakdown in the laser medium, and by using replicated simple subsystems for pulsed power. The infrared spectrum of the HF laser lies outside the ultraviolet range favored by the U.S. laser fusion program for optimum target coupling efficiency. However, the laser architecture we describe is an alternative for laser fusion systems which offers dramatic improvements in simplicity, compactness, and efficiency, which advantages will be even more pronounced when equally efficient, visible-wavelength chemical lasers become available.