Neutron transmission properties of concrete for a HEU storage vault from time of flight transmission measurements with a {sup 252}Cf source

High-Resolution Strain Mapping Through Time-of-Flight Neutron Transmission Diffraction

Materials Science Forum ◽

10.4028/www.scientific.net/msf.772.9 ◽

2013 ◽

Vol 772 ◽

pp. 9-13 ◽

Cited By ~ 3

Author(s):

Anton S. Tremsin ◽

Jason B. McPhate ◽

John V. Vallerga ◽

Oswald H.W. Siegmund ◽

Winfried Kockelmann ◽

...

Keyword(s):

High Resolution ◽

Spatial Resolution ◽

Time Of Flight ◽

Compact Tension ◽

Strain Mapping ◽

Neutron Transmission ◽

Neutron Counting ◽

Transmission Measurements ◽

Pulsed Neutron ◽

Pulsed Neutron Source

The spatial resolution of time of flight neutron transmission diffraction was recently improved by the extension of photon/electron counting technology to imaging of thermal and cold neutrons. The development of novel neutron sensitive microchannel plates enables neutron counting with spatial resolution of ~55 um and time-of-flight accuracy of ~1 us, with efficiency as high as 70% for cold and ~40% for thermal neutrons. The combination of such a high resolution detector with a pulsed collimated neuron beam provides the opportunity to obtain a 2-dimensional map of neutron transmission spectra in one measurement. The results of our neuron transmission measurements demonstrate that maps of strains integrated along the beam propagation direction can be obtained with ~100 microstrain accuracy and spatial resolution of ~100 um providing there are sufficient neutron events collected. In this paper we describe the capabilities of the MCP neutron counting detectors and present the experimental results of 2-dimensional strain maps within austenitic steel compact tension (CT) crack samples measured at the ENGIN-X beamline of the ISIS pulsed neutron source.

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Transmission of ocular media in labrid fishes

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2000.0679 ◽

2000 ◽

Vol 355 (1401) ◽

pp. 1257-1261 ◽

Cited By ~ 30

Author(s):

Ulrike E. Siebeck ◽

N. Justin Marshall

Keyword(s):

Visual System ◽

Great Barrier Reef ◽

Florida Keys ◽

The Other ◽

Barrier Reef ◽

Functional Roles ◽

Shallow Reef ◽

Transmission Properties ◽

Ocular Media ◽

Transmission Measurements

Wrasses (Labridae) are the second largest family of fishes on the Great Barrier Reef (after the Gobiidae) and, in terms of morphology and lifestyle, one of the most diverse. They occupy all zones of the reef from the very shallow reef flats to deep slopes, feeding on a variety of fauna. Many wrasses also have elaborately patterned bodies and reflect a range of colours from ultraviolet (UV) to far red. As a first step to investigating the visual system of these fishes we measured the transmission properties of the ocular media of 36 species from the Great Barrier Reef, Australia, and Hawaii, California and the Florida Keys, USA. Transmission measurements were made of whole eyes with a window cut into the back, and also of isolated lenses and corneas. Based on the transmission properties of the corneas the species could be split into two distinct groups within which the exact wavelength of the cut–off was variable. One group had visibly yellow corneas, while the corneas of the other group appeared clear to human observers. Five species had ocular media that transmitted wavelengths below 400 nm, making a perception of UV wavelengths for those species possible. Possible functional roles for the different filter types are discussed.

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Neutron transmission through pyrolytic graphite monochromators

Journal of Applied Crystallography ◽

10.1107/s0021889801002254 ◽

2001 ◽

Vol 34 (3) ◽

pp. 258-262 ◽

Cited By ~ 9

Author(s):

D. F. R Mildner ◽

M. Arif ◽

S. A. Werner

Keyword(s):

Thermal Neutron ◽

Pyrolytic Graphite ◽

Neutron Transmission ◽

Horizontal Beam ◽

Graphite Monochromator ◽

Monochromator Crystal ◽

Transmission Data ◽

Transmission Measurements

Thermal neutron transmission measurements have been made as a function of wavelength on a pyrolytic graphite monochromator crystal that has been set to diffract a horizontal beam at different take-off angles. The major dips in the transmission caused by the various reflections have been identified. These results can be used for the design of a beamline on which more than one instrument is placed. The transmission data show that it is best for the monochromator with the greatest (horizontal) take-off angle to be placed upstream, with monochromators with decreasing take-off angles progressively further downstream. The order of instruments for which the wavelength is greater than 0.43 nm is unimportant.

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Neutron transmission measurements of zinc and lead single crystals

Journal of Materials Science ◽

10.1007/bf00551912 ◽

1988 ◽

Vol 23 (12) ◽

pp. 4231-4236 ◽

Cited By ~ 4

Author(s):

M. Adib ◽

A. Abdel-Kawy ◽

Y. Abbas ◽

A. Ashry ◽

M. Wahba

Keyword(s):

Single Crystals ◽

Neutron Transmission ◽

Transmission Measurements

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Neutron Transmission of Single-Crystal Sapphire

Journal of Applied Crystallography ◽

10.1107/s0021889898005846 ◽

1998 ◽

Vol 31 (6) ◽

pp. 835-840 ◽

Cited By ~ 25

Author(s):

D. F. R. Mildner ◽

G. P. Lamaze

Keyword(s):

Single Crystal ◽

Cold Neutron ◽

Time Of Flight ◽

Transmission Time ◽

Transmission Characteristics ◽

Neutron Transmission ◽

Beam Port ◽

Single Crystal Sapphire ◽

Flight Measurements

Thermal and cold neutron transmission time-of-flight measurements have been taken on blocks of single-crystal sapphire. The transmission characteristics of single-crystal sapphire are not altered by irradiation for a number of years within a beam port at a reactor. Cooling the filter is only useful for the production of beams with the longest wavelengths. Even for poorer grade sapphire there is no degradation of the neutron transmission characteristics.

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