Hostname: page-component-7479d7b7d-8zxtt Total loading time: 0 Render date: 2024-07-11T06:22:20.589Z Has data issue: false hasContentIssue false

On Lensless Imaging of Organics with Neutrons, X-Rays, Helium Atoms and Low Energy Electrons: Damage and Iterative Phase Retrieval

Published online by Cambridge University Press:  02 July 2020

J.C.H. Spence
Affiliation:
Department of Physics and Astronomy, Arizona State University, Tempe, AZ, 85287
U. Weierstall
Affiliation:
Department of Physics and Astronomy, Arizona State University, Tempe, AZ, 85287
J. Fries
Affiliation:
Department of Physics and Astronomy, Arizona State University, Tempe, AZ, 85287
Get access

Abstract

Recent experiments with X-rays and high energy electrons have shown that image recovery from diffracted intensities is possible for non-periodic objects using iterative algorithms. Application of these methods to biological molecules raises the crucial problem of radiation damage, which may be quantified by Q = ΔE σie, the amount of energy deposited by inelastic events per elastic event. Neutrons, helium atoms and low energy electrons below most ionization thresholds produce the smallest values of Q (see for TMV imaged at 60 eV). For neutrons (λ = 10-2Å, and deuterated, 15N-abelled molecules) Q is ∼3000 times smaller (∼50 times for λ = 1.8Å) than for electrons (80- 500keV) and about 4x 106 times smaller than for soft X-rays (1.5Å). Since σe for neutrons is about 105 times smaller than for electrons (and about 10 times smaller than for soft X-rays), a 105 times higher neutron dose is required to obtain the same S/N in a phase contrast image compared with electrons, if other noise sources are absent.

Type
Quantitative Transmission Electron Microscopy of Interfaces (Organized by M. Rüehle, Y. Zhu and U. Dahmen)
Copyright
Copyright © Microscopy Society of America 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Miao, J. et al., Nature 400 (1999) 342344CrossRefGoogle Scholar
2.Weierstall, U. et al., submitted to Ultramic. 2000Google Scholar
3.Fienup, J.R., Applied Optics 21 (1982) 27582789CrossRefGoogle Scholar
4.Henderson, R., Quarterly Reviews of Biophysics 28 (1995) 171193CrossRefGoogle Scholar
5.Weierstall, U., Spence, J.C.H., Stevens, M., Downing, K.H.. Micron 30(4) p.335338 (1999)CrossRefGoogle Scholar
6.Bacon, G.E., Neutron scattering in chemistry, Butterworths, London (1977)Google Scholar
7.SNS website: WWW.sns.anl.govGoogle Scholar
8.Allman, B.E. et al., Nature 408 (2000) 158CrossRefGoogle Scholar
9.Fujiyoshi, Y. and Uyeda, N., Ultramic. 7 (1981) 189192CrossRefGoogle Scholar
10.Pauli., H.Atom, Molecule, and Cluster Beams I,” Springer, Berlin, (2000).CrossRefGoogle Scholar
11.Supported by ARO award DAAD190010500Google Scholar