ISSN 1027-4510, Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques, 2007, Vol. 1, No. 5, pp. 528–532. © Pleiades Publishing, Ltd., 2007. Original Russian Text © A.N. Artemiev, A.A. Snigirev, V.N. Korchuganov, A.G. Valentinov, V.V. Kvardakov, N.A. Artemiev, A.V. Zabelin, V.A. Rezvov, A.G. Maevskii, O.V. Naida, A.A. Dyatlov, 2007, published in Poverkhnost’. Rentgenovskie, Sinkhrotronnye i Neitronnye Issledovaniya, No. 9, pp. 35–39. 528 INTRODUCTION The transverse size of an electron beam in a storage ring is one of the most important characteristics of the storage ring as a synchrotron radiation (SR) source. This size, as well as the stored current and electron energy in the ring, control the SR source brightness. The transverse size of the electron beam in the stor- age ring is controlled by the ring emittance. The electron beam size is calculated by accelerator phys- ics methods [1]. Over the last decade, a new field of optics has been actively developed, namely, compound refractive lenses for hard x-rays. Such lenses are characterized by relatively small (not exceeding 1 mm) apertures. The first pioneering work on x-ray refractive lenses [2] was performed at the ESRF source (France). Cur- rently, studies on x-ray refractive optics continue almost exclusively at third-generation SR sources, i.e., ESRF and SPring-8 (Japan). Recently, studies on refractive lenses were also ini- tiated at the Kurchatov SR source. Planar parabolic glass–graphite x-ray lenses were developed in Russia with the participation of the authors of this paper. These lenses were studied at the ESRF; for one-dimensional focusing, the vertical size of the electron beam image was found to be 1.4 μm [3]. In this paper, we discuss the measurement of the transverse size of the electron beam using the x-ray refractive lens. KURCHATOV SYNCHROTRON RADIATION SOURCE Currently, the Kurchatov SR source (KSRS) oper- ates at the design energy of 2.5 GeV with a stored cur- rent of 100–150 mA in the multibunch mode [4]. The ring magnetic structure is optimized to achieve intense high-brightness photon fluxes from bending magnets and special radiation generators, i.e., wigglers and undulators, including those consisting of superconduct- ing wigglers. Figure 1 shows the schematic diagram of the accelerator storage system and SR beamlines. The storage ring consists of six identical reflection symmet- ric superperiods. Figure 2 shows one superperiod and emission points numbered along the electron beam direction: (1) the undulator gap center (an undulator or a multipole wiggler can be installed there), i.e., beam- line 0°; (2) the point of emission from a weak field of the bending magnet, i.e., beamline 0°; (3) the point of emission from the basic magnet field, i.e., beamline 5°20'; (4) the point of emission from the basic magnet field, i.e., beamline 17°; (6) the center of the gap where a superconducting or multipole wiggler can be installed, i.e., beamline 0°; (7) the point of emission from the basic magnet field, i.e., beamline5°20'; (9) the point of emission from the basic magnet field, i.e., beamline 17°. Here all angles are measured between the central ray of a given SR beamline and the direction of the preced- ing rectilinear gap. Table 1 lists the design values of the transverse elec- tron beam size. The betatron coupling factor ε z /ε x is 1%. Determination of the Electron Beam Size at the Kurchatov Synchrotron Radiation Source Using an X-Ray Refractive Lens A. N. Artemiev a , A. A. Snigirev b , V. N. Korchuganov a , A. G. Valentinov a , V. V. Kvardakov a , N. A. Artemiev c , A. V. Zabelin a , V. A. Rezvov a , A. G. Maevskii a , O. V. Naida a , and A. A. Dyatlov a a Russian Research Centre Kurchatov Institute, pl. Kurchatova 1, Moscow, 123182 Russia b European Synchrotron Radiation Facility (ESRF), 6 rue Jules Horowitz, BP 220, 38043 Grenoble Cedex 9, France c Laboratoire d’Optique Appliquee, ENSTA - Ecole Polytechnique, F-91761 Palaiseau Cedex, France Received June 15, 2006 Abstract—The electron beam size in the storage ring of the Kurchatov synchrotron radiation source at 2.5 GeV is determined using an x-ray two-dimensional parabolic refractive lens. The vertical size of the electron beam of the storage ring is found to be 270 μm, which exceeds the corresponding design value 140 μm (at a betatron coupling of 1%). The difference is explained by the imperfect geodetic arrangement of ring elements and the incomplete adjustment of the ring. DOI: 10.1134/S1027451007050059