Coherent bremsstrahlung research originated with the 1955 papers by Dyson and Uberall, Ter-Mikaelian, and Ferretti. Its intermediate status thirty years later has been documented by Saenz and Uberall in the book Coherent Radiation Sources (A. W. Saenz and H. Uberall, editors), Springer, Berlin 1985. The first precision experiments were carried out by Diambrini-Palazzi et al. (1960) in Frascati shortly after the theory had been developed; see also Timm (1969). After experimentation by dozens of electron accelerator laboratories all over the world, there are presently measurements being made by Arends et al. at the University of Mainz (MAMI, 855 MeV), Klein et al. at the University of Bonn (ELSA, 3 GeV), at CERN (20-170 GeV) by Avakian of the Yerevan Physics Institute and others, and with electron energies of 6 GeV at the Jefferson Laboratory, Newport News, VA (F. J. Klein, Catholic University, spokesperson). At Jefferson Lab, linearly polarized quasi-monochromatic coherent-bremsstrahlung photons [peaked at 1.8GeV, with polarization (after collimation) of 84%] are being used for the production (off protons) of ρ and ω mesons among others. Recent theoretical research deals with coherent bremsstrahlung in quasicrystals (Fusina, Langworthy, and Saenz, 2001), and with planar and axial coherent bremsstrahlung in a diamond crystal (Chouffani, Endo, and Uberall 2001-2), both at low energies. In the latter study, in which the concept of axial coherent bremsstrahlung is now stressed (while in the related processes of planar and axial channeling radiation this distinction is well known), photon emission occurs here not necessarily in the forward direction.

Perhaps the first idea about these processes may be found in a work of Williams (1934) and B. Ferretti (Nuovo Cimento 7, 1 18 (1950). Ferretti developed semi-qualitative calculations based on the Weiszacker-Williams method of the virtual quanta ¹. Also Ter-Mikaelian and Purcell, M. L. Ter-Mikaelian (Zh. Eksp. Teor. Fiz. 25, 296 (1953)), E. M. Purcell (private communication, 1955) performed calculations based on the virtual quanta method. Feinberg and Pomeranchuk and Dyson and Uberall (Phys. Rev. 99, 604 (1955)) presented other arguments. But perhaps in the first two most important papers ^4,5. H. Uberall carried out the full calculation by using the Born approximation and by obtaining results on the cross sections and polarization which could be compared with experiments. These theoretical results stimulated the performance of experiments by means of the high-energy electron accelerators. But first experimental results were in apparent contradiction with the theoretical ones.

Presentation tells in detail the history of discovery of the channeling radiation phenomenon. Theoretically it was predicted in 1974. My first publication appeared in Physics Letters in 1976. Experimentally, the effect was proven at the SLAC facility in Stanford by a joint USA-USSR team headed by Professor Panovsky on the American side with my consultancy support. The team included two American and two Soviet experimental physicists. Channeling radiation is the most intensive, polarized and directed radiation in physics. It was studied at all major centers equipped with accelerators for electrons and positrons. Presently, when engineering reached the level of implementing small compact accelerators, channeling radiation phenomenon is experiencing a new stage of development, since it provides very wide possibilities for application, being the most intensive, polarized, tunable X-ray and gamma-ray source, and in the X-ray spectrum represents a series of characteristic lines. The line width is of the order of several %, the number of lines, their intensity and position depend, for a specific energy, on the crystallographic properties of the crystal plane. It is very significant that with the help of one and the same crystal, one can get a great number of various tunable characteristic lines.

The trapping of electrons in the ponderomotive potential wells, which governs a free electron laser or inverse free electron laser at high gain, is analogous to the channeling of charged particles by atomic planes of a crystal. A bent crystal is analogous to a period-tapered free electron laser. This analogy is different from the well-known one between channeling radiation and undulator radiation.

The scheme for accurate quantitative treatment of the radiation from a crystalline undulator in presence of the dechanneling and the photon attenuation is presented. The number of emitted photons and the brilliance of electromagnetic radiation generated by ultra-relativistic positrons channeling in a crystalline undulator are calculated for various crystals, positron energies and different bending parameters. It is demonstrated that with the use of high-energy positron beams available at present in modern colliders it is possible to generate the crystalline undulator radiation with energies from hundreds of keV up to tens of MeV region. The brilliance of the undulator radiation within this energy range is comparable to that of conventional light sources of the third generation but for much lower photon energies.

The process of backward Compton scattering of a laser beam on relativistic particles and coherent radiation by relativistic electron in oriented crystal are investigated. It is shown that both these processes can be considered from the unique point of view. The comparative analysis of main characteristics of radiation sources that based on these processes is presented.

The processes of coherent and incoherent bremsstrahlung in thin diamond crystals and amorphous radiators are modeled and calculated by a Monte Carlo procedure. The implementation of realistic descriptions of the electron beam and the relevant physical processes have yielded an improved calculation of the measured intensities and photon polarizations.

The multiple scattering of ultra relativistic electrons in an amorphous matter leads to the suppression of the soft part of radiation spectrum (the Landau-Pomeranchuk-Migdal effect). A brief review of theoretical investigations carried out in NSC KIPT on the problem of multiple scattering effect for radiation of high energy particles in matter is presented. A comparison of results of the theory with the experimental data obtained on accelerators of SLAC and CERN at the study of the Landau-Pomeranchuk-Migdal effect in amorphous and crystalline matter is carried out. Special attention is centered on the study of multiple scattering effect for spectral-angular distributions of radiation by relativistic electrons in thin amorphous and crystalline targets.

The existing synchrotron radiation sources and the fourth generation x-ray sources, which are projected at SLAC, USA, and DESY, Germany, are very expensive. For this reason the search for the novel and cheaper sources using various types of radiation produced by 2-20 MeV electrons available at many hospitals, universities and firms in various countries is of great interest. A review of the physics, history, new theoretical and experimental results and of some applications is given with a purpose to consider the possibilities of construction of small tabletop sources of quasimonochromatic X-ray photon beams necessary for scientific, industrial, medicine and other applications.

An influence of transition radiation from relativistic electrons crossing a thin target on other emission processes involved in such electron interaction with the target is considered. Strong modification of characteristics of such emission mechanisms as bremsstrahlung and polarization bremsstrahlung and parametric X-rays in crystalline targets is discussed in this work.

A new setup for the measurement of electron channeling radiation has been taken into operation at the ELBE radiation source. First experiments at electron energies of 14.6 and 17 MeV using diamond type-IIa crystals were aimed at the verification of the dependence of the yield of channeling radiation on the crystal thickness. While the dissipative approach assuming an exponentially decreasing occupation function with an energy-dependent characteristic occupation length (l_occ) is able to describe the yield up to a thickness of about 2l_occ multiple scattering remarkable influences the yield at larger crystal thickness.

The importance and advantages of heterostructures and Quantum Wells (QWs) in device technology has made research challenging due to lack of direct techniques for their characterization. Particularly the characterization of strain and defects at the interfaces has become important due to their dominance in the electrical and optical properties of materials and devices. RBSiC has been used to study variety of defects in single crystalline materials, for nearly four decades now. Channeling based experiments play a crucial role in giving depth information of strain and defects. Ion beams are used for both material characterizations as well as for modifications. Hence it is also possible to monitor the modifications online, which are discussed in detail. In the present work, Swift Heavy Ion (SHI) modification of III-V semiconductor heterostnictures and MQWs and the results of subsequent strain measurements by RBSiC in initially strained as well as lattice matched systems are discussed. We find that the compressive strain decreases due to SHI irradiation and a tensile strain is induced in an initially lattice matched system. The incident ion fluence dependence of strain modifications in the heterostructures will also be discussed. The use of high energy channeling for better sensitivity of strain measurements in low mismatch materials will be discussed in detail. Wherever possible, a comparison of results with those obtained by other techniques like HRXRD is given.

The spectra of gamma radiation, which have been obtained in experiments with electrons -1 GeV in diamond and silicon crystals were analyzed for possible revealing of the features resulted from certain types of the particle motion. The analysis of obtained results shows that the radiation spectra essentially depend on the character of a particle motion in a crystal. The experimental data are compared with the results of the modeling of the radiation processes of the electrons with taking into account the dynamic of their motion in crystals.

An alternative way to the conventional positron sources - those which use high intensity electron beams impinging on thick amorphous targets - is presented here. It makes use of a compound target with an aligned crystal as a radiator, where the incident electron beam radiates a large number of photons (as channeling radiation or coherent bremsstrahlung) and an amorphous converter where these photons materialize in e⁺ e^- pairs. This new kind of target has been studied experimentally at CERN and the main results providing an accurate description of this positron source are given here. The ability of such a source to work in a linear collider scheme depending on its radiation resistance, the dedicated test carried out at SLAC on a W crystal are also described and the results are reported.

Optimization possibility of an intensive radiation source by electrons in crystals was considered. The technique is based on the Compton scattering of X-radiation. To obtain the initial "true" radiation spectrum, it is necessary to restore the spectrum of the measured scattered radiation by means of the inverse Compton transform.

In the coherent bremsstrahlung technique a thin diamond crystal oriented correctly in an electron beam can produce photons with a high degree of linear polarization.¹ The crystal is mounted on a goniometer to control its orientation and it is necessary to measure the angular offsets a) between the crystal axes and the goniometer axes and b) between the goniometer and the electron beam axis. A method for measuring these offsets and aligning the crystal was developed by Lohman et al, and has been used successfully in Mainz.² However, recent attempts to investigate new crystals have shown that this approach has limitations which become more serious at higher beam energies where more accurate setting of the crystal angles, which scale with l/Ebeam, is required. (Eg. the recent installation of coherent bremsstrahlung facility at Jlab, with Ebeam = 6 GeV ) This paper describes a new, more general alignment technique, which overcomes these limitations. The technique is based on scans where the horizontal and vertical rotation axes of the goniometer are adjusted in a series of steps to make the normal to the crystal describe a cone of a given angle. For each step in the scan, the photon energy spectrum is measured using a tagging spectrometer, and the offsets between the electron beam and the crystal lattice are inferred from the resulting 2D plot. Using this method, it is possible to align the crystal with the beam quickly, and hence to set any desired orientation of the crystal relative to the beam. This is essential for any experiment requiring linearly polarized photons produced via coherent bremsstrahlung, and is also required for a systematic study of the channeling radiation produced by the electron beam incident on the crystal.

The multiple scattering of ultra relativistic electrons in an amorphous matter leads to the suppression of the soft part of radiation spectrum (the Landau-Pomeranchuk-Migdal effect), and also can change essentially the angular distribution of the emitted photons. A similar effect should take place in a crystal for the coherent radiation of relativistic electron. The results of the theoretical investigation of angular distributions and polarization of radiation by a relativistic electron passing through a thin (in comparison with a coherence length) crystal at a small angle to the crystal axis are presented. The electron trajectories in crystal were simulated using the binary collision model, which takes into account both coherent and incoherent effects at scattering. The angular distribution of radiation and polarization were calculated as a sum of radiations from each electron. It is shown that there are nontrivial angular distributions of the emitted photons and their polarization that are connected to the superposition of the coherent scattering of electrons by atomic rows ("doughnut scattering" effect) and the suppression of radiation (similar to the Landau-Pomeranchuk-Migdal effect in an amorphous matter). It is also shown that circular polarization of radiation in the considered case is absent.

A comparative study of 1-5 keV P+ ions channeling in thin (dZ=5OOÅ) and thick Si(110), SiC(110), GaP(110) and AsGa(110) crystals has been carried out by computer simulation within binary collision approximation. The ion ranges, energy losses, angular and energy distributions, as well as depth profile distribution have been calculated. It was shown that for paraxial part of a beam the main contribution to the total energy losses comes from inelastic ones. It has been established that energy and depth profile distributions depend on width of channel in the direction <110> and mass of target atoms.

Quantum Chromo Dynamics (QCD) is the theory of strong interactions. While QCD has met with great success at high energy phenomena, our understanding of the workings of QCD at low energies, where the quarks are bound into nucleons and mesons, remains uncertain. GlueX will explore a crucial aspect of QCD that predicts exotic forms of matter created in certain high energy reactions. Such exotic particles, if observed, will provide us with an ideal tool to test, improve and understand aspects of QCD as never before and thus help solve the puzzle of confinement.

SPARC and SPARX are two different initiatives toward an X-ray FEL SASE source at LNF. SPARC is a high gain FEL project devoted to provide a source of visible and VUV radiation while exploiting SASE mechanism. An advanced Photo-Injector system, emittance self-compensating RF-gun plus a 150 MeV Linac, will inject a high quality e-beam into the undulator to generate high brilliance FEL radiation in the visible region at the fundamental wavelength, (530 nm). The production of flat top drive laser beams, high peak current bunches, and an emittance compensation scheme will be investigated together with the generation of higher harmonic radiation in the VUV region. SPARX is the direct evolution of such a high gain SASE FEL towards the 13.5 and 1.5 nm operating wavelengths, at 2.5 GeV. The first phase of the SPARX project, fiinded by Government Agencies, will be focused on R&D activity on critical components and techniques for future X-ray facilities as described in this paper.

Two methods of using the X pinch as a source of X-ray radiation for the radiography of dense plasmas and other objects are presented. These methods do not use pinholes, instead taking advantage of the small source size (<1 mm, and in some cases <1 pm) and short X-ray emission duration (< 2 ns , and < 20 ps in some cases) of the X pinch radiation. Detailed measurements of the emission characteristics of X pinches made using different wire materials and in different energy ranges using a set of X-ray diagnostics with high temporal and spatial resolution are presented. Several applications of the X pinch are discussed.

Novel sources of energetic photons are currently studied and developed at the Intense Laser Irradiation Laboratory of Pisa. They include: i) X-rays generated by plasmas produced with nanosecond and picosecond laser pulses. This kind of source has been recently optimised in terms of intensity, repetition rate, monochromaticity, which allowed novel techniques to be successfully tested as micro-radiography and differential mapping of tracing elements. ii) K-a X-ray emission of short duration due to the collision of energetic electrons generated during ultra-short femtosecond laser-solid interactions. iii) Monochromatic and ultra-short X-rays pulses generated via Thomson scattering of intense sub- picosecond pulses by relativistic electron bunches are currently being studied theoretically also with the aid of numerical codes. Electron bunches produced by both conventional beamlines and laser acceleration of electrons in plasmas are considered.

We propose an accelerator based 4^th generation source to provide coherent femtosecond light pulses down to the soft X ray range to the user community. The project is based on a CW 700 MeV to 1 GeV superconducting linear accelerator delivering high charge, subpicosecond, low emittance electron bunches with high repetition rate. This facility allows for providing High Gain Harmonic Generation seeded with high harmonics in gases, covering a spectral range down to 0.8 nm. In addition, two beam loops are foreseen to increase the beam current in using the energy recovery technique. They will accommodate fs synchrotron radiation sources in the IR, VUV and X ray ranges together with a FEL oscillator in the 10 nm range. A particular emphasis is put on the synergy between accelerator and laser communities. In particular, electron plasma acceleration will be tested. Hard X ray femtosecond radiation will be produced by Thomson Scattering. The first phase of the project, ARC-EN-CIEL phase 1, is now under study. A general overview is given.

Estimation of thc gain factor for the stimulated emission in a crystalline undulator is presented together with an explicit formulation of all physical conditions to be met when considering the phenomenon. A possibility of the emission stimulation in different photon energy ranges is analyzed. Numerical data on the total gain are presented for various projectiles and channels.

It is well known that when some conditions are fulfilled the intensity of the radiation produced by high energy particles in stratified media or the so-called "parametric Cherenkov radiation" is enhanced. On the other hand, it has been predicted and observed that in some materials the dielectric constant is greater than 1 in X-ray region near the absorption edges, and quasimonochromatic X-ray Cherenkov radiation (XCR) photons are produced with certain angular and narrow spectral distributions. Recently new formulae have been derived by the coherent summation method for the radiation produced by fast charged particles in multilayers consisting of thin alternating layers of two materials with different dielectric constants. In difference from the coherent transition radiation formulae obtained in WKB approximation or coherent summation method the new formulae take into account the reflection from the interfaces and is valid when the dielectric constants are greater andor less than 1. In this work we study the angular and spectral distributions of XCR using these formulae, compare the obtained results with the results obtained theoretically and experimentally in other works and discuss some possible experiments.

Transition radiation (TR) is emitted whenever a fast particle (γ > 1000) crosses the boundaries of a periodic structure. Since the prediction of this effect, many studies and tests have been accomplished to understand both the features of this radiation and the eventual practical applications. Nowadays. the main application of TR is particle identification in accelerator physics and astrophysics. Particle identification is one of the most challenging aspect of the experiments performed in these fields. In fact the experimental problems arisen in the recent accelerator physics pose stringent constraints on the detectors due to the high rates, severe background conditions, event final state complexity. On the other hand, the cosmic ray physics requires in some cases simple but refined and reliable devices to be used in outer space or otherwise huge and stable apparata for surface and underground laboratories. After a brief presentation of the TR phenomenon produced by ultrarelativistic particles and relative detectors, the state of the art of this particle identification technique relative to the more recent TRDs will be discussed.

Emission of parametric X-rays (PXR) in a multi-wave mode can provide its significant spectral-angular density increase. Distinctive features of multi-wave PXR generation were studied both theoretically and experimentally for high energies of electrons. The paper describes the main features of multi-wave PXR distributions and presents results of calculations showing that multi-wave generation mode can be observed also at low energy electron beams.

We discuss brieflv unusual properties of coherent bremsstrahlung, nanotube undulator (NUR) and Cherenkov x-ray radiation (CXR) from ultra-relativistic electrons and positrons in fullerene crystals and nanotubes.

The experimental and numerical data on electrical explosion of X-pinch are analyzed to develop the understanding of physical phenomena, which leads to generation of short, high intensive X-ray pulse. Main attention is given to MHD cumulative processes that are reasonable for creation of point-like regions of a non-equilibrium compressed plasma with high temperatures. The investigation based on the model of formation and development of hot plasma in the region of X- pinch neck. The model bases on the analysis of cumulative MHD compression of X-pinch neck and takes into account a radial compression of plasma by the magnetic field, outlet of plasma on axis, two-temperature processes of electron-ion relaxation, Joule heating, electron and ion viscous friction and dissipation. The radiation transfer is described by the dif- fusion approach in the axial direction and as the vacuum losses of radiation on radius. The lifetime of hot plasma is de- termined by a break of the neck in the result of generation of axial shock waves. The model of the scaling laws for hot spot plasma parameters and X-ray burst is described. One obtained that the duration of X-ray pulse is about several pico- seconds, the scale of spark region size is no large than one micron, and the X-ray pulse intensity is about 10¹⁷ W/cm².

The problem of hard transition radiation (HTR) produced by relativistic charged particle passing through periodically inhomogeneous medium with uniform velocity has been solved. Due to the medium inhomogeneities the phase of radiation vector potential varies periodically with amplitude growing. The application of approximation methods for solving the given problem shows that this amplitude is constant; the existing resonance condition between the radiation frequency and angle undergoes essential changes. This, in turn, changes the spectral distribution characteristics. The principle of harmonics equivalence in HTR is revealed. This principle says that the frequency distribution of radiation intensity is the same for different harnionics. For strongly inhomogenous medium frequency intervals of harmonics are overlapped. Consequently the HTR total intensity does not depend upon frequency up to the critical frequency. It is several orders higher as it was assume in former conceptions. The frequency distribution varies inversely with particle energy squared. On the other side the energy of photons at the critical frequency grows quadratically with the particle energy. Therefore, the energy losses do not depend on the particle energy, but under certain conditions can be of the same order as its energy.

The problem of acceleration of electron bunches interacting with powerful laser beam in a plasma-loaded inverse free electron laser (IFEL) is considered. It is shown that the presence of plasma in a free electron laser (FEL) results in a new mechanism of interaction between relativistic electrons and laser soft photons. This interaction maintains the synchronism during the induced absorption of laser photons by electrons. This method can provide high acceleration rates. It is also shown that the efficiency of this interaction increases essentially due to coherent effects in case of truncated dense electron bunches. As a result one obtains high acceleration rates in a wide energy region.

An expression for the spectral distribution of the hybrid radiation intensity is derived. It is shown that the transition radiation caused by the inhomogeneity of plasma and the undulator radiation due to the longitudinal oscillation of electron bunch are prevailing in soft and hard photon regions, respectively. The resonance dependence between the radiation frequency and its angle is the same along the whole spectrum. The peak in the hard photon region is formed as a result of the undulator radiation. The energy losses can be of the same order as the bunch energy but do not depend on the bunch energy. The characteristic features of the hybrid radiation are clarified.

The theory of narrowing for the hard spectra of sinusoidal undulator radiation taking into account the medium polarization is developed. Proposition for the experimental studies of the narrowing effect using crystalline undulator radiation has been obtained. The parameters and expected results of the proposed experiment are presented.

The expression for the gain of an free electron laser (FEL), in which a high current electron beam interacts with laser beat waves (LBW), is obtained. In case of a Gaussian distribution the gain has a maximum near the relativistic plasma frequency of the beam. For frequencies much higher than the plasma frequency, the gain decreases exponentially. In the case of a uniform distribution the gain decreases according to a power-like law, which produces higher values for the same frequencies. It is proposed to use asymmetrically distributed electron beams interacting with LBW to produce intense radiation in the submillimeter region.

The processes of scattering and radiation at collision of a beam of relativistic electrons with short and long bunches of relativistic charged particles are considered. The analysis of these processes at a head-on collision of a beam of electrons with short bunch of charged particles, and at falling of electrons beam under a small angle to an axis of long bunch of particles is executed. It is shown, that character of scattering and radiation by electrons in these cases essentially differs. It is connected with features of development of these processes in a field of long-distance Coulomb potential of particles of bunch.

When a bunch travels off axis across structures whose shape is not uniform, such as RF cavity, it generates longitudinal and transverse wake fields. We use the Homdyn code to study the dynamics behaviour of an off-axis bunch, thus the new code version described includes wake fields and space charge on the bunch's slices centroids. Finally, we give an evaluation of the emittance degradation at the exit of the traveling wave structures of the SPARC project when structures are misaligned respect to the nominal axis.

Current methods for synthesizing and studying carbon nanotubes (CNTs) as well as nanochannel structures based on CNT arrays, Al₂O₃ and Si0₂ are discussed in this paper. A few processes of material self-organization provide for preparing the ordered patterns of such nanocapillaries. Potential applications of these nanochannel structures in the field of quanta and particle transportation are treated.

Our theoretical calculations show that multi-wall nanotubes (MWNTs) can serve as x-ray waveguides. Two types of waveguiding exist based either on Fresnel or Bragg reflections of x-rays from nanotube walls. Moreover, fast electrons propagating through MWNTs can emit "channeled" transition (CTR) or parametric x-ray (PXR) types of radiation with much greater intensity than in ordinary crystals.

Recent research progress for the particle beam interaction with nanostructures at Shanghai Institute of Applied Physics (SINAP) is reported. The experimental results on channeling of charged particles along nanostructures at low energy are demonstrated. The coherent scattering effect of ion beam transportation in carbon nanotubes (CNTs) is investigated. The direct measurement of beam intensity of angular distribution through AAO or CNTs/AAO sample, and the measurement of backscattering spectra of Au/Si pass AAO or CNTs/AAO sample are made. It is found that for incident angle of about 0.3" the maximum of Au/Si backscattering signal pass the sample can be detected. On the other hand, the simulation study for the channeling of charged particle along the nanostructure is also investigated.

The idea of an X-ray waveguide has its origin in 1974 from a paper of Spiller and Segmuller¹, but only then years ago^2-5 it has been demonstrated that a submicrometer X-ray beam could be produced by the waveguides. From the first experiments up to now the efficiency has been improved by three orders of magnitude⁶, and a nanometer beam confined in two directions has been also produced⁷. Recently, as it will be shown in this paper, the possibility to use waveguides with laboratory sources has been also demonstrated. The unique characteristics of the beam produced by the waveguides (nanometer beam size, high degree of coherence, well defined beam profile, etc.) make it appealing for several applications in microimaging, microdiffraction, etc. In this work the principles of X-ray waveguides together with the view of the present activity and applications of this optics will be presented.

Influence of the chemical composition of a glass on the main formation parameters of polycapillary optics products is discussed. The technological results for fabricating the polycapillary structures are presented. The structures and examples for testing such items are described.

The review of technical possibility and investigations, which are performed at the Completely Automatic Measurement Facility (Russian sounds as PAVICOM), is presented. A very efficient Completely Automated Measuring Facility (PAVICOM) for track-detector data processing in the field of nuclear and high-energy particle physics has been constructed in the Lebedev Physical Institute. PAVICOM is widely used in Russia for experimental data treatment of track detectors (emulsion trackers, solid trackers) in high and low energy physics, cosmic ray physics, etc. The PAVICOM provides the essential improving the efficiency of experimental studies. In contrast to semi-automated microscopes widely used until now, the PAVICOM is capable of performing completely automated measurements and analysis of charged-particle tracks in nuclear emulsions and track detectors without employing hard visual work, In this case, track images are recorded by CCD-cameras and then are digitized and converted into files. Thus, automated measurements and online analysis accelerate the experimental-data processing by approximately thousand times. Completely automatic devices similar to PAVICOM came into operation in scientific centers of Japan, Italy, CERN, and some other countries. In Russia, the PAVICOM is the only facility of such a type. Its possibilities are so wide that satisfy not only needs of investigations being performed in LPI but are also used by other Russian laboratories and Institutes. Thus, PAVICOM actually plays the role of multipurpose user center.

We have fabricated and tested short focal-length compound refractive lenses for X-rays (CRLs) and considered its application for focusing coherent beams. The lens is designed in the form of glass capillary filled by micro-air-bubbles embedded into epoxy. The interface between the bubbles formed 90 to 196 spherical bi-concave microlenses with curvature radius equals to the capillary one. When compared with CRLs manufactured using other methods, the micro-bubble lenses have shorter focal lengths with higher transmission for moderate energy X-rays (e.g. 7 - 12 keV). The lenses are inexpensive and are ideally suited for focusing X-rays generated by high power single pulsed operation coherent X-ray sources with Source size 50-100 microns. We used beamline 2-3 at the Stanford Synchrotron Radiation Laboratory (SSRL) to measure focal lengths between 100-150 mm and absorption apertures between 90 to 120 pm. Transmission profiles were measured giving, for example, a peak transmission of 27 % for a 130-mm focal length CRL at 8 keV. The focal-spot sizes were also measured yielding, for example, an elliptical spot of 5 × 14-μm² resulting from an approximate 80-fold demagnification of the 0.44 × 1.7 mm² source.

The results of theoretical (provision for the future) and experimental (last focusing) research of synchrotron radiation (SR) (5-20 keV) passage through polycapillary lens (Kumakhov semilens) are presented. The description of experimental setup and researched capillary structure (capillary lens) parameters are given. The procedure of the studied optics adjustment and registration method of the radiation passed through a lens are described. The analysis of experimental data is also given.

PolyCAD is a CAD program designed for X-ray photon tracing in polycapillary optics. To understand the PolyCAD code and its results, theoretical basis of X-ray transmission by a single cylindrical and conical channel (monocapillarics) are discussed. Then the simplest cases of cylindrically and conically shaped polycapillary optics are examined. PolyCAD allows any type of X-ray source to be simulated like an X-ray tube of finite beam dimensions or an astrophysical object in combination with different kinds of polycapillary optics. The radiation distribution images formed on a screen located at various focal distances are discussed. The good agreement of some of the PolyCAD results with those reported in earlier papers validate the code. In this paper we will show simulations for sources of different types: i) a point-focus, located at finite and infinite distances, ii) a X-ray tube-like sources and iii) three dimensional sources, like a couple of spheres. In the last case we was also able to reconstruct the source objects. Work is in progress to include in the code many other polycapillary optical shapes, such as semi-lenses and full-lenses. In the next future we will consider the wave features of the X-ray propagation inside capillary channels that will allows to complete our code for describing all the peculiarities of radiation propagation. In such away, we will bc able to describe X-ray channeling along curved surfaces and than go down to channeling in nanostructurcs.

We present here some methods for the production of organized systems formed by carbon nanotubes and suitable for nano-beams generation and handling. In particular methodologies based on Chemical Vapour Deposition (CVD), chemically induced assembling and alignment by dielectrophoretic processes are examined and their capacity to produce assembling of nanostructured materials with defined architecture is discussed

DAΦNE-Light is the Synchrotron Radiation laboratory at the Laboratori Nazionali di Frascati (LNF)¹. Three beamlines were commissioned since spring 2003 to exploit parasitically the intense photon emission from DAΦNE, the 0.5 1 GeV storage ring routinely circulating over 1 A of electrons. The soft X-ray beamline utilizes a wiggler source and, by a double-crystal fixed-exit monochromator, it is operational in the distinguishing energy window 1.5 - 4 keV range to be extended from the "water window" toward 6 keV. At present, the research activity is focused on X-ray Absorption Spectroscopy (XAS): precisely, X-ray Absorption Near Edge Spectroscopy (XANES) on the inner electronic levels of light elements and transition metals from Al to Ge and both d- and f-shells of higher Z atoms. Preliminary tests of X-ray imaging have been performed in view of applying different focusing optics, namely policapillary systems in trasmission and/or bent mica diffractor in back-reflection, for X-ray microscopy and spectromicroscopy experiments. The use of polycapillary systems (lenses, halflenses, capillaries) for studying features of radiation transportation by such structures (X-ray channelling, focusing, bending, etc.) has been planned.

At the sunrise of the Kumakhov optics, the latter was enormously attractive for neutron scientists eager to take advantage from focused neutron beams. However, in spite of this initial enthusiasm, rear neutron applications of polycapillary optics are mostly limited either to feasibility studies or to non-scattering techniques. The reason for such a drawback is a serious degradation in the momentum resolution of neutron scattering methods caused by increased divergence of focused beams. However, limited brightness of present day neutron sources (both existing and coming) requires rethinking the current situation. Neutron lenses are successfully tested for low Q-resolution applications providing an enormous increase of neutron flux at small samples. Moreover, some recent developments in the field of neutron instrumentation allow us to overcome the resolution problem by decoupling the angular resolution and the incident beam divergence thus opening the opportunity for the use of focusing neutron optics in some high Q-resolution application. Further advances in technology required to improve the performance of neutron polycapillary optics, also in combination with modem methods of polarization of neutron beams, are discussed.

We present in this paper the basic principle of novel X-ray optics composed of confocal nested reflecting mirrors that allows more photons from a source of X-ray radiation to be accepted compared with a single mirror and that can be fabricated using relatively cheap microfabrication tools. In order to optimize relevant parameters of the proposed system, we developed a ray- tracing code for nested surfaces. The choice of parameters of the mirror system (length, position, eccentricity, etc.) is carried out starting from theoretical considerations, which have been recently developed and, through simple equations, give optimal parameters of X-ray mirrors providing a maximal acceptance angle of the system.

Research studies, which are currently held in the field of radiation material science, can be divided into two main directions. First direction is connected with study of structure features and material properties, which were exposed to long-term high dose neutron radiation. These are generally high-performance constructional materials and fuel elements of commercial power nuclear reactors. Researches of this direction are aimed to determine physical reasons of material degradation under irradiation, often with unstable parameters. Second direction is connected with monitored irradiation of materials using big facilities such as research nuclear reactors, charge particle accelerators for analysis of change of materials' defect structure in order to forecast stability andor degradation of their properties (primarily, irradiation stability) after long-term irradiation.

Two samples of the new type of X-ray spectral elements - sliced multilayer grating (SMG) for 4.4-5 nm interval have been produced and tested. Spectra of A1 discharge plasma were obtained with one of the SMGs. A novel experimental approach based on a flow proportional counter was introduced and used to measure diffraction efficiency of another SMG. The properties of the SMG are discussed.

Five different measurement techniques for experimental estimation of focal spot sizes in X-ray tubes are described. They are: the pinhole, the slit, the edge, the scanning and the grid- wire methods 11-61. The same techniques can be used for experimental estimation of focal spot sizes in X-ray lenses. We are developing methods using magnification, high resolution and digital detection of a precise edges response to obtain quantitative estimates of focal spot dimensions for X-ray tubes and lenses for the energy range from 6 to 60 keV. Agreement between the wire and the edge methods is rather good, while three others give only rough estimations, when we use them for measuring focal spot sizes in the range from 0.0lmm to 0.05mm.