ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
Irradiation experiments on biological samples with monochromatic ultrasoft x-rays are inevitable in elucidating the initial process in radiobiological phenomena. However, intense light sources with continuous spectra in this wavelength region have not been available until recently. Synchrotron radiation is the best light source for the study because of its intense, continuous emission spectrum. The purpose of the project is to develop a grazing incidence ultrasoft x-ray monochromator for radiation biology studies using synchrotron radiation as a light source. The following characteristics are required in the monochromator, namely, (1) high throughput with moderate resolution; (2) wide beam area with uniform intensity; (3) little contamination of higher order lights; and (4) easy operation and maintenance. Considering the above requirements, a plane-grating type monochromator (PGM) is adopted. The monochromator consists of two premirrors (M1 and M2), a plane grating (1200 l/mm), a concave focusing mirror (r=12 m) and an exit slit. Two premirrors with different incident angles can be used interchangeably to eliminate higher order lights in the desired wavelength region. Wavelength of 30–70 A is available when M1 is used and 80–250 A when M2 is used. Expected wavelength resolution is 1% when the width of exit slit is 300 μm. All vacuum chambers accommodating these optical elements are bakable in order to attain ultrahigh vacuum. Wavelength is controlled by a microcomputer system equipped with a stepping motor and an encoder. This monochromator will be installed at beamline 12C at the Photon Factory, National Laboratory for High Energy Physics, and will be open to outside users in radiation biology by the end of 1988.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1140799
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