scholarly journals Precision neutron-interferometric measurement of the coherent neutron-scattering length in silicon

1998 ◽  
Vol 58 (2) ◽  
pp. 1475-1479 ◽  
Author(s):  
A. Ioffe ◽  
D. L. Jacobson ◽  
M. Arif ◽  
M. Vrana ◽  
S. A. Werner ◽  
...  
2003 ◽  
Vol 90 (19) ◽  
Author(s):  
T.  C. Black ◽  
P.  R. Huffman ◽  
D.  L. Jacobson ◽  
W.  M. Snow ◽  
K. Schoen ◽  
...  

2004 ◽  
Vol 70 (1) ◽  
Author(s):  
P. R. Huffman ◽  
D. L. Jacobson ◽  
K. Schoen ◽  
M. Arif ◽  
T. C. Black ◽  
...  

2001 ◽  
Vol 684 (1-4) ◽  
pp. 632-634 ◽  
Author(s):  
V. Huhn ◽  
L. Wätzold ◽  
Ch. Weber ◽  
A. Siepe ◽  
W. von Witsch ◽  
...  

1968 ◽  
Vol 109 (2) ◽  
pp. 465-470 ◽  
Author(s):  
E. Fuschini ◽  
C. Maroni ◽  
I. Massa ◽  
A. Uguzzoni ◽  
G. Vannini ◽  
...  

1966 ◽  
Vol 16 (3) ◽  
pp. 105-108 ◽  
Author(s):  
E. Baumgartner ◽  
H. E. Conzett ◽  
E. Shield ◽  
R. J. Slobodrian

2019 ◽  
Vol 219 ◽  
pp. 05002
Author(s):  
Christopher Haddock ◽  
Katsuya Hirota ◽  
Takashi Ino ◽  
Masaaki Kitaguchi ◽  
Kenji Mishima ◽  
...  

Recently published results and ongoing experimental efforts to search for deviations from the inverse square law of gravity at the nanometer length scale using slow neutron scattering from the noble gases are discussed. Using the pulsed slow neutron beamline BL05 at the Materials and Life Sciences Facility at J-PARC, we measured the neutron momentum transfer (q) dependence of the differential scattering cross section for the noble gases He, Ne, Ar, Kr, and Xe. By comparing to the distributions obtained using pseudo-experimental Monte Carlo simulations and forming ratios between Xe and He, we placed an upper bound on the strength of a new interaction as a function of interaction length λ which improved upon previous results in the region λ < 0.1 nm, and remains competitive in the larger λ region. Additionally we describe how we are using our technique to extract relative values of the total neutron scattering cross sections of the noble gases, as well as how we plan to measure the neutron-electron scattering length using the NOVA instrument on BL21 at J-PARC.


2020 ◽  
Vol 124 (1) ◽  
Author(s):  
R. Haun ◽  
F. E. Wietfeldt ◽  
M. Arif ◽  
M. G. Huber ◽  
T. C. Black ◽  
...  

1988 ◽  
Vol 132 ◽  
Author(s):  
J. A. Eastman ◽  
J. E. Epperson ◽  
H. Hahn ◽  
T. E. Klippert ◽  
A. Narayanasamy ◽  
...  

ABSTRACTNanophase titanium, prepared by the gas-condensation method both as aggregated powder and in lightly compacted discs, has been studied by conventional small angle neutron scattering, and by use of contrast variation methods. The contrast has been changed (a), isotopically, by means of deuterated/protonated solvents distilled into the specimen and (b) by progressive incremental oxidation of the Ti particles using fixed doses of low-pressure oxygen. It was shown that some evolution of the small angle pattern for lightly compacted nanophase Ti occurred over a period of several months at 300 K. Contrast matching by external solvent works well and has allowed the scattering lengths of oxidized and unoxidized specimens to be followed. The results imply that the scattering from metal and oxide can be separated under suitable conditions. The partial oxidation experiments indicate that there is both a fast and slow oxidation at 300 K. Also, during slow oxidation, high scattering length density scattering centers were formed whose number increased, but whose size remained the same at about 2 nm; these centers are tentatively assumed to be TiO2.


1994 ◽  
Vol 376 ◽  
Author(s):  
Rex P. Hjelm ◽  
Wesley Wampler ◽  
Michel Gerspacher

ABSTRACTAs part of our work on the structure of composite materials we have been exploring the use of small-angle neutron scattering using the method of contrast variation to dissect the component form, structure and distribution. This approach has resulted in a new look at very old problemreinforcement of elastomers by carbon black.Using this approach we studied an experimental high surface area (HSA) carbon black and a gel of "HSA-bound" rubber in cyclohexane/deuterocyclohexane mixtures. HSA in cyclohexane is found to be short rodlike particle aggregates. The aggregates have a shell-core structure with a high density graphitic outer shell and an inner core of lower density amorphous carbon. The core is continuous throughout the carbon black aggregate, making the aggregate a stiff, integral unit. Contrast variation of swollen composite gels shows that there are two length scales in the gel structure. Above 10 Å, scattering from carbon black predominates, and below 10 Å the scattering is from both carbon black and the elastomer. The HSA in the composite is completely embedded in polyisoprene. An estimate of the carbon black structure factor shows strong exclusion of neighboring aggregates, probably from excluded volume effects. The surface structure of the carbon black is unaltered by the interactions with elastomer and appears smooth over length scales above about 10 Å. These results show that contrast variation can provide information on composite structure that is not available by other means. This information relates to the reinforcement mechanism of elastomers by carbon blacks.


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