title: Estimation of soft X-ray and EUV transition radiation power emitted from the MIRRORCLE-type tabletop synchrotron.
abstract: The tabletop synchrotron light sources MIRRORCLE-6X and MIRRORCLE-20SX, operating at electron energies E(el) = 6 MeV and E(el) = 20 MeV, respectively, can emit powerful transition radiation (TR) in the extreme ultraviolet (EUV) and the soft X-ray regions. To clarify the applicability of these soft X-ray and EUV sources, the total TR power has been determined. A TR experiment was performed using a 385 nm-thick Al foil target in MIRRORCLE-6X. The angular distribution of the emitted power was measured using a detector assembly based on an NE102 scintillator, an optical bundle and a photomultiplier. The maximal measured total TR power for MIRRORCLE-6X is P(max) approximately equal 2.95 mW at full power operation. Introduction of an analytical expression for the lifetime of the electron beam allows calculation of the emitted TR power by a tabletop synchrotron light source. Using the above measurement result, and the theoretically determined ratio between the TR power for MIRRORCLE-6X and MIRRORCLE-20SX, the total TR power for MIRRORCLE-20SX can be obtained. The one-foil TR target thickness is optimized for the 20 MeV electron energy. P(max) approximately equal 810 mW for MIRRORCLE-20SX is obtained with a single foil of 240 nm-thick Be target. The emitted bremsstrahlung is negligible with respect to the emitted TR for optimized TR targets. From a theoretically known TR spectrum it is concluded that MIRRORCLE-20SX can emit 150 mW of photons with E > 500 eV, which makes it applicable as a source for performing X-ray lithography. The average wavelength, \overline\lambda = 13.6 nm, of the TR emission of MIRRORCLE-20SX, with a 200 nm Al target, could provide of the order of 1 W EUV.
authors.affiliation: Photon Production Laboratory Ltd, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu-shi, Shiga 525-8577, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Toyosugi
authors.forename: H
authors.initials: H
authors.lastname: Yamada
authors.forename: D
authors.initials: D
authors.lastname: Minkov
authors.forename: M
authors.initials: M
authors.lastname: Morita
authors.forename: T
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: S
authors.initials: S
authors.lastname: Imai
mesh_terms: D000535:Aluminum / Q000528:radiation effects; D004583:Electrons; D008433:Mathematics; D011874:Radiometry; D017356:Synchrotrons / Q000295:instrumentation; D014466:Ultraviolet Rays; D014965:X-Rays
chemical_list: D000535:Aluminum