Radiation damage and its influence on source requirements for high resolution x-ray holography
Soft x-ray holography offers the possibility of obtaining high resolution, 3-D images of living cells and organelles therein. To achieve a specified resolution, a certain number of photons must be scattered by the smallest features of interest within the sample. This requires a certain irradiating fluence, the magnitude of which depends on the wavelength of the x rays and the scattering cross- sections of the features. Unfortunately, irradiation of the sample will be accompanied by the absorption of x rays. If the dose is large, the sample will be damaged, possibly compromising the quality of the image. A theoretical study of the scattering and absorption of x rays during the creation of a hologram is described. Using a new prescription for scattering by condensed biological materials (e.g., protein and/or DNA) within the aqueous environment of a cell, we estimate the irradiating fluence required for a certain resolution and the associated sample dose. The relative merits of different x-ray wavelengths are discussed. A wavelength of about 44{angstrom}, just outside the water window'' (23.2--43.7{angstrom}), appears to be optimal in that the required fluence and dose are minimized, while reasonable x-ray penetrability is maintained. Estimates are given for the minimum source energy required and the maximum duration of an exposure to capture an image before blurring due heat induce motion. The use of colloidal gold tagging can enhance image contrast and reduce the required irradiating fluence and sample damage. 6 refs., 5 figs.
- Research Organization:
- Lawrence Livermore National Lab., CA (USA)
- Sponsoring Organization:
- DOE/DP
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5360724
- Report Number(s):
- UCRL-100702; CONF-8905192-2; ON: DE90002508; TRN: 89-031057
- Resource Relation:
- Conference: Conference on X-ray microimaging for the life sciences, Berkeley, CA (USA), 24-26 May 1989
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ANIMAL CELLS
HOLOGRAPHY
RADIATION INJURIES
RADIOINDUCTION
DAMAGE
SOFT X RADIATION
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
ELECTROMAGNETIC RADIATION
INJURIES
IONIZING RADIATIONS
RADIATION EFFECTS
RADIATIONS
X RADIATION
550602* - Medicine- External Radiation in Diagnostics- (1980-)