Search

The time-lapse observation of the electrodeposition of copper in copper sulfate solution was performed by imaging X-ray fluorescence from the copper deposition. The X-ray fluorescence was directly imaged with a full-field Wolter mirror microscope, which was constructed at the Photon Factory. Controlling the electric current in the solution from 0 to 71.7 µA, the deposition of copper on a Pt cathode was directly observed by imaging its X-ray fluorescence. One exposure time for obtaining an X-ray fluorescence image was 80 s. Then, it was 17 min later from the beginning of the electrolysis when the X-ray fluorescence image of the electrodeposition is observed for the first time. At this exposure time, the detection limit of the mass of copper was estimated to be 0.60 pg/image, which was calculated using test samples of 1.00×10-3–1.00 mol/l copper sulfate solutions.

Extreme ultraviolet (EUV) radiation from laser-produced plasma has been studied for mass-production of the next generation semiconductor devices with EUV lithography. A full set of experimental databases are provided for a wide range of parameters of lasers and targets. These data are utilized directly as a technical guide-line for EUV source system design in the industry as well as used to benchmark the radiation hydrodynamic code, including equation-of-state solvers and advanced atomic kinetic models, dedicated for EUV plasma predictions. Present status of the LPP EUV source studies is presented.

We have been developing an EUV light source by laser-produced plasma for the use of EUV lithography system under the Leading Project promoted by MEXT. The project aims at understanding physics of laser plasma EUV source and providing database and guidelines for the practical EUV source. Progresses in theoretical modeling and experimental results are briefly reported.

Properties of extreme ultraviolet (EUV) and particle emissions from laser-produced tin (Sn) plasma were experimentally investigated for use in industrial applications. Dependence of EUV emission on the initial thickness of Sn overcoat on a plastic sphere was studied to clarify the minimum mass needed to keep sufficient conversion to EUV and minimize plasma debris. EUV emission from low-density targets showed narrower spectra peaked at 13.5nm, attributed to reduction of satellite line emissions in the spectrum foot and opacity broadening at the peak. It is shown that not only the EUV generation but also ion spectra are significantly affected by the Sn coat thicknesses.

A new two-color pumping method for multi-frequency Raman generation was developed using deuterium gas combined with KrF excimer lasers. To obtain a powerful two-color radiation, the pump and its first Stokes (Stokes shift Ω = 179 cm −1 ) were simultaneously amplified by a KrF amplifier. Thirty pure rotational Raman sidebands were generated by focusing two-color radiation in cooled deuterium.

A new simple picosecond KrF laser source was developed by the saturated amplification of sharp leading-edge pulses generated by fast Pockels cell and stimulated Raman scattering (backward Raman pulse compression and four-wave anti-Stokes generation in methane gas). Short-laser pulses of 1.1 ps and 3.2 mJ with a beam quality closed to that of a diffraction-limited pulse were generated at a repetition rate of 10 Hz. The measured brightness contrast ratio of the main pulse to ASE was more than 1010. A stable and long-life operation has been achieved using a fast Pockels cell.

Full-field x-ray scattering microscopic images were obtained with a Wolter mirror (×10 magnification). A synchrotron radiation white beam (4–20 keV) from a bending magnet beamline at the Photon Factory was used to obtain x-ray scattering images. The system was available for multi-kilo-electron-volt x-ray range (4–12 keV) with the Wolter mirror. The image was formed only with scattered x rays from the object, which is kind of a dark-field image. Very low absorptive materials could be imaged with this microscope. Sensitivity of the system was evaluated and also the detection limit was estimated.

In order to increase the gain length product for the Ha line (13.4 nm) of hydrogen-like Nitrogen in the exploding type pumping of irradiating a 30 nm thick SiN membrane target with a few ps pulse, the pumping laser system is up-graded. For crucially important issue of suppressing a pre-pulse, the energy of the front-end of the pumping laser system was increased by one order. Beam pattern of the pumping laser pulse on the vacuum chamber window was improved with an image relay. In order to start experiments of a water-window laser, chirping pulse amplification in e-beam pumped KrF laser system is planned.

An X-ray fluorescence imaging microscope with a Wolter-type grazing-incidence mirror objective was constructed at beamline 39XU of SPring-8. Monochromatic X-rays in the energy range 6–10 keV were used for X-ray fluorescence excitation of the specimens. Recording X-ray fluorescence images of a test specimen (Cu, Ni and Fe wires) from 50 different angles of view, three-dimensional tomographic reconstructions were obtained. These wires could be reconstructed selectively by changing the energy of the excitation X-rays. A synthetic diamond could also be imaged three-dimensionally.

An X-ray fluorescence imaging microscope with a Wolter-type objective mirror (magnification: 13) has been constructed at beamline 39XU of SPring-8. Monochromatic X-rays (DeltaE/E approximately 10(-4)) in the energy range 6-10 keV were used for X-ray fluorescence excitation of the specimens. Using two monochromatic X-rays above and below the absorption edge of a particular element, a two-dimensional image of the element could be obtained. As a result, two-dimensional element mapping of the test specimens (Cu, Co, Ni, Fe and Ti wires) and constituent minerals (Fe, Mn and Ti) of a rock specimen (a piemontite-quartz schist) became possible.

We are developing a photoelectron microscope on a laboratory scale by using a laser-produced plasma X-ray source. It consists of a laser-produced plasma X-ray source, a monochromator with a toroidal mirror and a concave grating, a grazing incidence focusing mirror (Wolter type-I) and a hemispherical electrostatic electron energy analyzer. In this study, we intend to measure photoelectron spectrum images. The X-ray beam spot size was 9 μm×13 μm. An Au evaporated microchannel plate (MCP) was used as a sample.

Vacuum ultraviolet (VUV) and soft X-ray measurements are important means of diagnosing impurities in magnetically confined plasmas used in fusion research. Recently, space- and time-resolving flat-field VUV (150–1050 Å) and soft X-ray (20–350 Å) spectrographs have been constructed by using aberration-corrected concave gratings with varied-spacing grooves which give a wide simultaneous spectral coverage on a microchannel-plate intensified detector. Calibration experiments have been performed at beamlines 11A and 11C at the Photon Factory of the High Energy Accelerator Research Organization. The relative efficiency of the VUV spectrograph has been measured for P-polarization geometry in the spectrograph. In the soft X-ray spectrograph, efficiencies have been obtained for several different points of irradiation on the grating along the groove direction and for two (S and P) polarization geometries.

A low-density solid xenon (Xe) target has been developed as laser-produced plasma (LPP) extreme ultraviolet (EUV) source. Xe gas was cooled to below the condensation temperature, and liquid Xe was sprayed from a swirl atomizer into a low-pressure atmosphere. Microparticles of liquid Xe were rapidly cooled by their own latent heat of evaporation, and became a solid micrometer-sized powder. The most frequent particle diameter under an atomizing pressure of 0.3 MPa was 114 µm, and the apparent density was 0.2 g/cm3, 1/13 of the density of conventional solid Xe. The apparent production rate of the powder was 2.2 cm3/s.

Hot ions with a strongly anisotropic distribution are created by radio-frequency waves and are sustained in the GAMMA 10 tandem mirror. The main power drain from the hot ions is accounted for by classical transport processes. The dominant loss is electron drag, which is confirmed in auxiliary electron heating experiments. The anisotropic distribution of hot ions is also examined in terms of neutron yield from D - D fusion reactions. The ion pressure and the anisotropy drive unstable waves near the ion cyclotron frequency. A dispersion relation and spatial distributions of the unstable waves are examined by use of magnetic probes and reflectometry cross-polarization scattering measurements. The hot-ion plasma contains a multi-shell structure of impurities creating concentric layers of pressure-driven azimuthal velocity with strong shears.

Imaging characteristics of channel plate x-ray collimators have been investigated in the low energy range for applications of two-dimensional x-ray spectrometer. Improvement of the degradation of spatial resolution due to x-ray reflection inside a hollow channel has been considered by utilizing a focusing action of the channel plate collimator. Spatial extent of images through the channel plate collimator have been measured systematically by using a low energy point x-ray source and have been compared with results of ray-tracing calculations. It is shown that the spatial extent of the image consisting of the focusing component is limited by the geometrical divergence of the channel plate collimator. The possibility of two-dimensional imaging spectroscopy as well as the focusing action is discussed.

Behavior of neutral hydrogen in the central-cell of the GAMMA 10 tandem mirror is investigated by measuring spatial-profiles of Hα line-emission and neutral transport simulation. Hα-emission detectors are newly installed horizontally in the vacuum chamber and detailed profiles of the Hα emission are measured. It is found that hydrogen atoms introduced from the gas puffer at the mirror throat are localized around the gas puffer in the steady state phase of ICRF-heated plasmas. The DEGAS neutral transport code is applied to calculate axial density profiles of atomic and molecular hydrogen. In the DEGAS code, the mesh model is modified to take into account variations along the magnetic-field line. The simulation result fairly agrees with the above experimental result. In a standard ICRF-heated plasma, an experiment with modulated gas-puffing is performed. Characteristics of particle confinement in the main plasma are discussed by using the experimental and the simulation results.

In this paper we describe the experimental results on the evaluation of fueling in the central region of the GAMMA 10 tandem mirror on the basis of the neutral pressure balance, plasma spectroscopy and atomic and molecular processes with numerical simulations. Quasi steady-state plasmas are achieved by optimizing the combination of gas puffing and ICRF pulse, which simplify the quantitative evaluation of fueling. The total fueling in the central region deduced from the pressure measurement near the plasma boundary is compared with the amount of end-loss flux which is measured by an end loss analyzer (ELA). It is found that the amount of fueling increases slightly with the ICRF power due to the enhancement of recycling in the central region and agrees well with the behavior of end-loss flux. Results of impurity-injection experiments are also described from the viewpoint of recycling processes.

A spatial imaging vacuum ultraviolet (VUV) spectrograph has been constructed for simultaneous observation of spatial and spectral distributions of plasma radiation in the wavelength range 150–1050 A. The spectrograph consists of an entrance slit of limited height which provides spatial resolution, an aberration‐corrected concave grating with varied spacing grooves which gives a flat‐field spectral output plane, and an image‐intensified two‐dimensional detector system. The basic characteristics of the spectrograph have been investigated by ray‐tracing calculations. The expected performance has been confirmed through experiments using a dc glow discharge source on the reciprocal dispersion, the spatial resolution, or the incident angle dependence of spectral images. VUV spectra with spatial and time resolution have been obtained successfully in the GAMMA10 tandem mirror experiment.

We propose a new scheme for high conversion efficiency from laser energy to 13.5 nm extreme ultra violet emission within 2 % band width, a double pulse laser irradiation scheme with a tin droplet target. We consider two-color lasers, a Nd:YAG laser with 1.06 µm in wavelength as a prepulse and a carbon dioxide laser with 10.6 µm in wavelength for a main pulse. We show the possibility of obtaining a CE of 5 - 7 % using a benchmarked radiation hydro code. We have experimentally tested the new scheme and observed increase of CE greater than 4 %. We show many additional advantages of the new scheme, such as reduction of neutral debris, energy reduction of debris ions, and decrease of out of band emission. We also discuss debris problems, such as ion sputtering using newly developed MD simulations, ion mitigation by a newly designed magnetic coil using 3-PIC simulations and tin cleaning experiments.

A laser-produced tin (Sn) plasma is an attractive extreme-ultraviolet(EUV) light source for the next generation lithography in terms of its brightness and compactness. Radiative properties and hydrodynamics of the laser-produced Sn plasmas are quite important for investigating the optimum conditions for EUV generation. Several experiments have been performed to clarify the above issues;(i) EUV spectra emitted from isolated Snq+ (5 < q < 15) ions and opacity spectrumof a 30-eV Sn plasma have been measured as fundamental data for accurate modelingradiation energy transport in plasmas, (ii) electron density profile in 13.5 nmemission dominant region of a laser-produced Sn plasma was measured with a laserinterferometer for understanding hydrodynamics of an EUV source plasma. (iii) benchmarking one-dimensional (1D) radiation-hydrodynamic simulation codewith multiple laser beam irradiated spherical 1D Sn plasma. Based on the experimentalresults and calculations, it was found that optically thinner plasma emits 13.5 nm light more efficiently. Optical depth of Sn plasma is actively controlledwith changing laser pulse duration and the use of low-density porous target.

Extreme ultraviolet (EUV) radiation from laser‐produced plasma has been thoroughly studied for application in mass‐production of the next generation semiconductor devices. Comprehensive experimental databases are provided for a wide range of parameters of lasers and targets. The atomic models are benchmarked with spectroscopic measurements not only for laser‐produced plasma (LPP) but also for EUV emissions from magnetic‐confinement plasmas or the charge exchange for uniquely ionized ions colliding with rare‐gas targets. These experimental data are utilized in the industry as well as used to benchmark the radiation hydrodynamic code, including equation‐of‐state solvers and advanced atomic kinetic models, dedicated for EUV plasma predictions. Present status of the LPP EUV source studies is presented.

Laser-produced Sn plasma is an efficient extreme ultraviolet (EUV) light source, however the highest risk in the Sn-based EUV light source is contamination of the first EUV collection mirror caused by debris emitted from the Sn plasma. Minimum mass target is a key term associated with relaxation of the mirror contamination problem. For design of the optimum minimum mass Sn target, opacity effects on the EUV emission from the laser-produced Sn plasma should be considered. Optically thinner plasma produced by shorter laser pulse emits 13.5 nm light more efficiently; 2.0% of conversion efficiency was experimentally attained with drive laser of 2.2 ns in pulse duration, 1.0 × 10 11 W/cm 2 in intensity, and 1.064 μm in wavelength. Under the optimum laser conditions, the minimum mass required for sufficient EUV emission, which is also affected by the opacity, is equal to the product of the ablation thickness and the required laser spot size. Emission properties of ionized and neutral debris from laser-produced minimum mass Sn plasmas have been measured with particle diagnostics and spectroscopic method. The higher energy ions have higher charge states, and those are emitted from outer region of expanding plasmas. Feasibility of the minimum mass target has been demonstrated to reduce neutral particle generation for the first time. In the proof-of-principle experiments, EUV emission from a punch-out target is found to be comparable to that from a static target, and expansion energy of ion debris was drastically reduced with the use of the punch-out target.

For EUV lithography the generation of clean and efficient light source and the high-power laser technology are key issues. Theoretical understanding with modeling and simulation of laser-produced EUV source based on detailed experimental database gives us the prediction of optimal plasma conditions and their suitable laser conditions for different target materials (tin, xenon and lithium). With keeping etendue limit the optimal plasma size is determined by an appropriate optical depth which can be controlled by the combination of laser wavelength and pulse width. The most promising candidate is tin (Sn) plasma heated by Nd:YAG laser with a pulse width of a few ns. Therefore the generation technology of clean Sn plasma is a current important subject to be resolved for practical use. For this purpose we have examined the feasibility of laser-driven rocket-like injection of extremely mass-limited Sn or SnO 2 (punched-out target) with a speed exceeding 100m/s. Such a mass-limited low-density target is most preferable for substantial reduction of ion energy compared with usual bulk target. For high average power EUV generation we are developing a laser system which is CW laser diode pumped Nd:YAG ceramic laser (master oscillator and power amplifier system) operating at 5-10 kHz repetition rate. The design of practical laser for EUV source is being carried out based on the recent performance of >1 kW output power.

An analytical formula for maximizing radiation efficiency from a laser-produced plasma is derived. The maximum efficiency is achieved when the plasma expansion distance during laser heating is equal to the laser absorption length. The dependence of the radiation efficiency on the plasma density is confirmed by experiments using a particle-cluster target. By creating a relatively uniform density plasma with a $300\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ diameter by dispersing ${\mathrm{S}\mathrm{n}\mathrm{O}}_{2}$ particles coated on a Si wafer, the conversion efficiency at 14 nm, as high as 4 times as that for a Sn plate target, is achieved.

In this paper, we described a laser plasma source for Extreme Ultraviolet Lithography (EUVL) based on a water droplet target. We successfully generated stable multi-kHz water droplets with several hundred μm diameter using our experimentaql setup. We realized a good synchronization of laser with droplet by employing droplet-probing photo diode (PD) signal to trig YAG laser timely. We got EUV emission with pulse to pulse stability of 3.4% (1σ) from this droplet region without being destroyed due to hot laser plasma formation from the previous droplet.

Particle-cluster tin target is presented as the solution of a 100W EUV source for EUVL. Theory for maximizing conversion efficiency of a laser-produced plasma is derived and the theory is experimentally confirmed by using a dispersed SnO2 particles. The EUV intensity 4 times higher than that from a plasma on a solid Sn plate target is observed at the optimized density. The achieved conversion efficiency for dispersed particles is estimated to be as high as 3%/(2π str 2%BW) or higher from the value for a Sn plate of 0.8% measured by using two multilayer mirrors and a calibrated photodiode. Theoretical consideration reveals that larger diameter plasma enables higher EUV power. The particle-cluster can be delivered at multi kHz rep-rate by using water droplet. Experimental confirmation of delivering particles by droplets is also reported.

In order to protect a multilayer mirror from sputtering or ion implantation, high-energy ions ejected from EUV source plasma are to be blocked. We propose use of a laser-produced plasma as an ultra-fast shutter. Ion signal form an ion-source plasma dropped abruptly by two orders of magnitude to a noise level after the shutter plasma generation. The stopping effect for the high-energy ions was observed to reduce as the distance of shutter plasma expansion increases, but the suppression of ions below detection level was observed up to 10 mm. We concluded that reduction of ion signal was caused by in-take of the source plasma flow into the stream of the shutter plasma.

Debris-free generation of a tin plasma was demonstrated in the cavity-confined configuration. Narrow band emission at 13.7-nm was observed in an emission spectrum of a cavity confined tin plasma. The spectral efficiency was as high as 12% and we found the conversion efficiency could reach 6%/2π str ultimately while lots of works are required to achieve this value. We also confirmed a magnetic field has some effect of stopping a plasma.

Laser plasma light source using double pulses laser irradiation and through-hole method is proposed as a mass-limited target srouce for extreme UV (EUV) radiation. After minimum necessary material is supplied using the ablation laser from a solid target, only ablated material is irradiated with the heating laser to produce a high-temperature plasma, and EUV radiation is extracted passing through the hole formed in the solid target. Fundamental concept of this scheme, EUV radiation and great reduction of particle debris were experimentally confirmed.

Magnetic field shield for laser produced plasma (LPP) had been investigated. The interaction between expanding LPP and magnetic field is not described by Lorentz force, but, may be described by magneto hydro dynamics. When a magnetic field strength of 0.6T was placed between LPP and a faraday cup, attainment ratio of plasma to a faraday cup was decrease to 20%. The attainment ratio was decreased from 0.4 to 0.25 with varying the distance between the plasma and the magnetic field from 10 mm to 70 mm. And, it was observed that plasma detoured around a magnetic field.

We succeeded in generating a strong narrowband peak at 13.7 nm in a cavity confined Sn plasma. Fraction of the energy within 2% bandwidth at 13.7 nm against the total radiation spectrum was 11.3%. In our experiment, the plasma is generated not on a solid plate but in a cavity as described below. A YAG laser pulse ablates the surface of a concave structure Sn target in order to supply the material for plasma generation. The next laser pulse with 1064nm wavelength heats the ablated material to generate a high temperature plasma. The ablation YAG laser is focused to 600μm diameter with a flux of 10 J/cm 2 . The heating YAG laser is focused to 100μm diameter at a delay time of 30 ns after the laser ablation. Emission spectra are observed using a grazing incidence Hitachi flat-field grating and a back side illuminated CCD detector. Fraction of the energy at 13.7nm within 2% bandwidth in the whole radiation energy was 11.3%. However, the intensity of the spectrum peak was about 1/10 against the plane Sn target LPP source. When nano (less than 200 nm diameter) particle SnO 2 deposited on a 100nm-thick Si3N4 membrane were irradiated, a sharp peak was observed. The intensity of the spectral peak of the nano particle SnO 2 target LPP source was as high as that of the plane Sn target LPP source. The EUV energy within 2% bandwidth at around 13.7 nm to the whole radiation energy of the nano particle SnO 2 target LPP source was 7.4%.

The first result is presented of an X-ray fluorescence microscope with a Wolter mirror in combination with a CCD camera used as an energy-resolved two-dimensional detector in photon-counting mode. Two-dimensional elemental maps of metallic wires, such as Fe, Co, Ni and Cu, and inclusions of a synthesized diamond could be obtained with an energy resolution of 350 eV.

A Zernike-type one-dimensional phase-contrast x-ray microscope with a Wolter mirror was developed and tested. A Cu wire or an Al phase plate was placed at the back focal plane of the Wolter mirror objective. A dark-field image of a Cu mesh could be obtained at 9.00 keV by using the Cu wire as a direct beam stop, and a phase-contrast image could be obtained at 8.97 keV by using the same optics. A polyethylene telephthalate (PET) fiber of 9 μm in diameter could be obtained at 8.97 keV by using the Al phase plate, which could seldom be observed without the phase plate. These results agreed fairly well with simulated images.

Laser-driven expansion of pure-tin microdroplets was demonstrated to produce an efficient and low-debris extreme-ultraviolet (EUV) light source. The pre-expansion is indispensable for resolving the considerable mismatch between the optimal laser spot diameter (∼300μm) and the diameter (∼20μm) of microdroplets containing the minimum-mass Sn fuel for generating the required EUV radiant energy (∼10mJ/pulse). Explosive expansion of microdroplets was attained by using a laser prepulse, whose intensity was at least 3×1011W∕cm2. The expanded microdroplet was irradiated with a CO2 laser pulse to generate EUV light. A combination of low density and long-scale length of the expanded microdroplet leads to a higher EUV energy conversion efficiency (4%) than that (2.5%) obtained from planar Sn targets irradiated by a single CO2 laser pulse. This scheme can be used to produce a practical EUV light source system.

In the development of a high power EUV source used in the EUV lithography system, it is important to understand basic physics of EUV plasma and to optimize laser and target conditions. We have been constructed EUV database of laser-produced tin plasma by the theoretical and experimental studies. On the basis of our understanding, the optimum conditions of lasers and plasmas were clarified, and we proposed the guidelines of laser plasma to obtain clean, efficient and high power EUV source for the practical EUV lithography system. In parallel to such studies, novel targets and high power laser system to generate the optimized EUV source plasma have been developed. Recent progresses of our program are presented.

EUV emission from spherical and planer targets were precisely characterized as an experimental database for use in EUV source generation at high repetition rates. In the single-shot base experiments, conversion efficiency as high as those for the plasma geometry has been demonstrated. The integrated experiment was made with 10 Hz plasma generation, obtained conversion efficiency is low mainly due to unstable positioning of the droplets.

The optimum plasma conditions of extreme ultraviolet (EUV) light source for lithography were experimentally clarified that is optically thin and minimum mass Sn plasma generated from a limited size target. Sn plasma is quite opaque for EUV light of 13.5 nm in wavelength, therefore 13.5 nm light emitted from deep within a Sn plasma is strongly absorbed, thus optically thin plasma production is essential for efficient EUV generation. Contamination of EUV optics caused by debris emanated from laser irradiated Sn targets is a serious problem in the Sn based EUV source system. Target residue around the laser spot is the dominant source of neutral debris, which can be reduced with supplying the minimum mass target containing the minimum number of Sn atoms required for sufficient EUV generation. Spectral purity of generated EUV light is an important requirement to expose clear mask image on a photo-resist film without chromatism. Out-of-band radiation in the vacuum ultraviolet range is dominantly radiated from the laser spot peripheral. Target size must be equal to the laser spot size to suppress the out-of-band radiation.

The effect of the initial density of xenon (Xe) targets on extreme ultraviolet (EUV) emission has been investigated. With decreasing initial density, it was found that the spectral width around 11 nm becomes broad, and the intensity of 13.5 nm emission increases. The maximum conversion efficiency (CE) for solid Xe targets is approximately 0.6% at a 2×1011 W/cm2 of laser intensity, whereas that for the low-density targets is approximately 0.7% at a 4×1011 W/cm2. The spectral broadening with decreasing initial density can be attributed to the change in optical thickness of laser-produced plasmas. The enhancement of CE is attributed to optically thick plasma formation.

An ultraviolet (UV) short-pulse intensity diagnostic method using atmosphere as a nonlinear medium was developed. This diagnostic method is based on evaluating the ion charge of the two-photon ionization of atmospheric oxygen upon irradiation with a UV (238–299 nm) short-pulse laser. The observed ion signal increased proportionally to the input intensity to the power of ∼2.2, during the two-photon ionization of atmospheric oxygen. An autocorrelator was constructed and used to successfully measure a UV laser pulse of ∼400 fs duration. Since this diagnostic system is used in the open-air under windowless conditions, it can be set along the beam path and used as a UV intensity monitor.

A two-dimensional imaging soft X-ray monochromator is now under development. The main components of this spectrometer are a channel plate collimator (CPC) and multilayer mirrors. We have applied this monochromator to obtain soft X-ray images of GAMMAIO tandem mirror plasmas. In order to obtain clear images in a low energy X-ray regime, we have utilized and tested a focusing effect of the CPC. Ray-trace simulations were carried out under the same conditions as the experiments. After comparison of these results, we have confirmed that the focusing effect of the CPC is useful in practical use. Monochromatized two-dimensional soft X-ray images have been successfully taken on the tandem mirror experiment.

Diamagnetic rotation of a cylindrical plasma has been investigated in the GAMMA 10 tandem mirror by using a UV-visible TV spectrograph system. A parameter-fitting technique is developed for obtaining spectra of local impurity emission profiles and diamagnetic rotation is determined from the impurity density profile.

In the development of an efficient, clean and high power EUV source, it is important to understand basic physics of EUV plasma and to optimize laser and target conditions. Our program aims at constructing database on EUV radiation from the laser-produced plasma by the theoretical and experimental studies, and providing technical guidelines for the practical EUV source used in the EUV lithography system. Recent progresses of our program will be presented.