Plans for a scanning transmission x-ray microscope

Journal Article · Tue Jan 01 04:00:00 EST 1980 · Ann. N.Y. Acad. Sci.; (United States)

DOI:https://doi.org/10.1111/j.1749-6632.1980.tb47215.x· OSTI ID:6590042

Kirz, J; Burg, R; Rarback, H

Ultrasoft x-ray photons in the 24044 A range have significant advantages over electrons in the imaging of relatively thick, wet, unstained biological specimens. Considerations of specimen damage alone have indicated a resolution limit on the order of 100 A for specimens up to several micrometers thick. Although this resolution has been approached in contact microscopy of thin specimens, the technique is cumbersome and may be inappropriate for high resolution study of thicker specimens. Among the alternatives, the scanning technique has serveral advantages over the use of post-specimen optics in the formation of high resolution images. The radiation exposure can be lowered by the elimination of the large losses often encountered in magnifying optics and detectors. In addition, alignment and registration procedures can be more easily implemented. Finally, the specimen can be maintained in an open environment, since the path length between the vacuum window and the detector can be made short enough to allow appreciable transmission of the radiation. Researchers have embarked on a program to build a high resolution scanning transmission microscope. Our microscope will focus ultrasoft synchrotron radiation down to a small spot whose size is, essentially, the resolution of the microscope. The sample will be scanned through the spot in air and the transmitted radiation will be detected by a flow proportional counter and used to modulate the intensity of the displayed image. Information about the elemental composition of the sample can be obtained either by comparing two images taken at wavelengths stradding an absorption edge or by fluorescence microscopy using harder radiation and energy-dispersive detectors.

• Research Organization: State Univ. of New York, Stony Brook
• OSTI ID: 6590042
• Journal Information: Ann. N.Y. Acad. Sci.; (United States), Journal Name: Ann. N.Y. Acad. Sci.; (United States); ISSN ANYAA
• Country of Publication: United States
• Language: English

Related Subjects

440300* -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
DESIGN
DIAGNOSTIC TECHNIQUES
DOSES
ELECTROMAGNETIC RADIATION
IMAGES
IONIZING RADIATIONS
MICROSCOPES
MICROSCOPY
PHOTON TRANSMISSION SCANNING
RADIATION DOSES
RADIATIONS
RESOLUTION
X RADIATION