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We have designed a family of new continuous wave linear accelerators for electron-based industrial, medical, and environmental irradiation applications. Our ten reliable, small, inexpensive high-power modular accelerators will produce beams with energies from 0.6 to 6.0 MeV in increments of 600 keV, each with a current selectable from O to 50 mA. We have constructed the critical gun-1st section model, which has undergone the first beam test. We have achieved beam parameters of 600 keV, 10 mA, and 6 kW and we have demonstrated all the innovations of our initial design.

We propose to generate X-rays by having an electron beam in a magnetic field cross thin foil radiators multiple times. We report that our simulation and analytic results agree and indicate that the X-ray yield will be at least doubled over that from a single, equivalently thick, target.

Several facilities are used to test trasmissive optics of the IFE target chamber and KrF laser driver in regard of transient and residual radiation-induced absorption in the range of 150–1200nm. Comparative study of radiation darkening of various fused silica glasses, high-purity CaF2 ,M gF2, and Al2O3 crystals under irradiation by 300keV electrons, soft (hν = 6–20keV) and hard (hν ∼ 400keV) X-rays is done and better radiation-proof optical materials are selected; the opposite effect of optics bleaching under UV laser light is observed. c

We have numerically simulated a laser-excited symmetric periodic diffraction structure, comprising conducting plates deposited onto dielectric film substrates, intended for the high-gradient acceleration of charged particles. The parameters of this structure were optimized to provide that a relativistic particle is accelerated in the near field diffraction zone over the entire spatial period. The possibility of eliminating the parasitic perpendicular components of the electric and magnetic fields in the plane of symmetry by means of bilateral laser irradiation is considered.

X-Ray generations utilizing Thomson scattering fill in the gap that exists between conventional and synchrotron-based X-ray sources. They are expected to be more intense than X-ray tubes and more compact, accessible and less expensive than synchrotron. In this work, two operation modes of Thomson X-ray source are documented: quasi CW(QCW) and a pulsed one are considered for material sciences and medical applications being implemented currently at Synchrotron Radiation (SR) facilities., 12 pages

This paper is devoted to the analysis of the general trends in the nucleon number dependence of the experimental root-mean-square (rms) charge radii. It is based on the data obtained by different methods of combined treatment of (i) radii changes determined from optical and—to a lesser extent—Kαx-ray isotope shifts, and (ii) absolute radii measured from muonic and electronic scattering experiments. These methods have recently been developed and now updated including experimental data up to the beginning of 2008. Thus, new sets of rms nuclear radii have been obtained covering 865 isotopes for 76 elements from 1 Ht o96Cm. New information on the isotopic and isotonic behaviour of the nuclear charge radius is obtained with a high accuracy compared to that of the directly measured radii values for the same element. Of special interest is that concerning the light elements and the appearance of non-traditional magic neutron and proton numbers, as N = 6, 14 and Z = 14; the doublemagic properties of 96 Zr are discussed in more detail. A quantitative criterion is introduced, which points to the peculiarities in the radii trend and offers an opportunity to investigate it more closely. The results provide important information which may serve as a guide to incorporate essential new features into the theoretical approaches. (Some figures in this article are in colour only in the electronic version)

Valerian Grigor'evich Shevchenko (Obituary) Yu V Galaktionov, Mikhail V Danilov, Vladimir S Imshennik et al. Anatoli Aleksandrovich Vlasov (obituary) I P Bazarov, N N Bogolyubov, Boris B Kadomtsev et al. Physics and astronomy at Moscow University (On theUniversity's 225th anniversary) B I Spasski, L V Levshin and V A Krasil'nikov Configurational splitting of the giant dipole resonance in atomic nuclei B S Ishkhanov, I M Kapitonov, Vladimir G Neudachin et al. German Stepanovich Zhdanov (Obituary) N B Brandt, B K Vanshten, A S Ilyushin et al. Yuri Mikhalovich Shirokov (Obituary) N N Bogolyubov, S N Vernov, Vasilii S Vladimirov et al. Dmitri Vladimirovich Skobel'tsyn (Obituary) A M Baldin, N G Basov, Vitalii L Ginzburg et al. Igor' Borisovich Teplov (Obituary)

The formation of the giant dipole resonance (GDR) in light (A < 40) atomic nuclei is studied. It is shown that the main feature of the GDR in these nuclei is configurational splitting, which is caused by the sharp drop of the deep 0s and 1p shells in 1p- and 2s, 2d-shell nuclei, respectively, and by the approximate spin-isospin SU4 symmetry (1p-shell nuclei). As a result of this a single dipole state is not formed in light nuclei and the GDR is spread over groups of levels in different regions of the excitation energy. The role of this phenomenon in the system of modern ideas about the formation of collective states of nuclei is indicated and problems for further experimental and theoretical study are formulated.

Using bremsstrahlung from the 35 MeV betatron the 26 Mg( γ , x p) reaction cross section has been obtained in the excitation energy region up to 29 MeV. The role of isospin splitting in the formation of a giant dipole resonance is discussed in the case of light nuclei.

The experimental data on proton stripping and pick-up on even-even targets with Z from 20 to 28 are analyzed jointly using the spin and parity data obtained in different experiments. The general features in the distribution of the spectroscopic strengths among nuclear states are revealed. Spins of 10 nuclear states and parity of one state are predicted. The shell-structure parameters are calculated. It is found that the single-particle forces are essential in the above-noted experiments.

The technique of the difference proton spectra is used to study the decay properties of highly excited states of the 58 Ni and 60 Ni isotopes in the energy region of the giant dipole resonance. The proton transition strengths to specific final states from particular initial states have been extracted. Experimental data are interpreted in terms of isospin splitting of the giant dipole resonance.

This article reports the results of the computer simulation of parameters of the disk-and-washer accelerating structure for the CW racetrack microtron. Effective shunt impedance of the structure is optimized taking into consideration the parasitic modes. Capture section is simulated and thermal conditions are analyzed.

The (γ, ni) cross sections in the region of the giant dipole resonance (GDR) of the self-conjugate 24Mg nucleus have been obtained on the basis of the experimental (γ, pi) cross sections (i specifies states of the final nucleus) and the isospin symmetry of photonucleon decays. In the (γ, ni), (γ, pi) cross sections, the total photonucleon cross sections, and the photoabsorption cross sections, we have identified the components due to semidirect GDR decay using the ratios of the semidirect decay widths resulting from the R-matrix theory. In the integrated photoabsorption, photoproton, and photoneutron cross sections the probability of semidirect decays was found to be 57–67%, 45–60%, and 80–90%, respectively. The semidirect decays dominate in the low-energy ( 1 d 2 s → 1 f 2 p and 1 p 1 2 → 1 d 2 s and the statistical decays dominate in the high-energy (> 22 MeV) group of the transitions 1 p 3 2 → 1 d 2 s .

Using the semimicroscopic nuclear vibration model and the combined model for giant resonance decay, we have calculated the giant dipole resonance structure and the partial photo-nucleon cross sections for 32S. The theoretical parameters were estimated from the spectroscopic data. The calculation satisfactorily describes the structure and decay characteristics of the 32S giant resonance. It has been shown that the statistical mechanism plays a significant role in the photodisintegration of 32S.

A simple model for decay of the giant dipole resonance is described that takes into account the semidirect, pre-equilibrium, and equilibrium mechanisms of the photonucleon emission. The semidirect photoeffect is treated within the framework of the R -matrix theory in the shell model. The wave function for the doorway dipole state is constructed using the generator procedure that offers the possibility to obtain simple formulas for a calculation of the semidirect component of the photonucleon spectra. The problem of the inclusion of isospin effects is treated. A reasonable agreement between theoretical and experimental photoproton spectra has been obtained.

The transverse and longitudinal emittance forming line (EFL) of the race-track microtron of INP MSU is described. The work presents the principles of operation, parameters of EFL elements, description of rf power supply system and automated control system. The method of EFL tuning and experimental results are discussed.

Experimental data on pickup and stripping reactions have been used to investigate single-particle properties of the most stable nuclei of the 1d2s shell. Populations of proton subshells and single-particle energies of the nuclear hamiltonian are obtained.

The spectral-angular distribution of the polarization bremsstrahlung of relativistic electrons crossing a thin aluminium foil is measured. The earlier predicted strong difference between polarization bremsstrahlung properties for amorphous and polycrystalline targets is observed for the first time.