Nuclear particle first of class

1966 ◽  
Vol 44 (19) ◽  
pp. 28-29
Keyword(s):  
Author(s):  
P. Fraundorf ◽  
J. Tentschert

Since the discovery of their etchability in the early 1960‘s, nuclear particle tracks in insulators have had a diverse and exciting history of application to problems ranging from the selective filtration of cancer cells from blood to the detection of 244Pu in the early solar system. Their usefulness stems from the fact that they are comprised of a very thin (e.g. 20-40Å) damage core which etches more rapidly than does the bulk material. In fact, because in many insulators tracks are subject to radiolysis damage (beam annealing) in the transmission electron microscope, the body of knowledge concerning etched tracks far outweighs that associated with latent (unetched) tracks in the transmission electron microscope.With the development of scanned probe microscopies with lateral resolutions on the near atomic scale, a closer look at the structure of unetched nuclear particle tracks, particularly at their point of interface with solid surfaces, is now warranted and we think possible. The ion explosion spike model of track formation, described loosely, suggests that a burst of ionization along the path of a charged particle in an insulator creates an electrostatically unstable array of adjacent ions which eject one another by Coulomb repulsion from substitutional into interstitial sites. Regardless of the mechanism, the ejection process which acts to displace atoms along the track core seems likely to operate at track entry and exit surfaces, with the added feature of mass loss at those surfaces as well. In other words, we predict pits whose size is comparable to the track core width.


2002 ◽  
Vol 389-393 ◽  
pp. 1439-1444 ◽  
Author(s):  
Alexander M. Ivanov ◽  
Nikita B. Strokan ◽  
Alexander A. Lebedev ◽  
D.V. Davydov ◽  
N.S. Savkina ◽  
...  

2006 ◽  
Vol 40 (10) ◽  
pp. 1227-1231 ◽  
Author(s):  
A. M. Ivanov ◽  
A. A. Lebedev ◽  
N. B. Strokan

Author(s):  
Brian C. Archambault ◽  
Joseph R. Lapinskas ◽  
Jing Wang ◽  
Jeffrey A. Webster ◽  
R. P. Taleyarkhan

Unprecedented capabilities for the detection of nuclear particles are presented by tensioned metastable fluid states which can be attained via tailored resonant acoustic systems such as the acoustic tensioned metastable fluid detection (ATMFD) systems. Radiation detection in tensioned metastable fluids is accomplished via macro-mechanical manifestations of femto-scale nuclear interactions. Incident nuclear particles interact with the dynamically tensioned metastable fluid wherein the intermolecular bonds are sufficiently weakened such that the recoil of ionized nuclei generates nano-scale vapor cavities which grow to visible scales. Ionized nuclei form preferentially in the direction of incoming radiation, therefore, enabling the capability to ascertain information on directionality of incoming radiation — an unprecedented development in the field of radiation detection. Nuclear particle detection via ATMFD systems has been previously reported, demonstrating the ability to detect a broad range of nuclear particles, to detect neutrons over an energy range of eight orders of magnitude, to operate with intrinsic detection efficiencies beyond 90%, and to ascertain information on directionality of incoming radiation. This paper presents advancements that expand on these accomplishments, thereby increasing the accuracy and precision of ascertaining directionality information utilizing enhanced signal processing-cum-signal analysis, refined computational algorithms, and on demand enlargement of the detector sensitive volume. Advances in the development of ATMFD systems were accomplished utilizing a combination of experimentation and theoretical modeling. Modeling methodologies include Monte-Carlo based nuclear particle transport using MCNP5 and complex multi-physics based assessments accounting for acoustic, structural, and electromagnetic coupling of the ATMFD system via COMSOL’s Multi-physics simulation platform. Benchmarking and qualification studies have been conducted with special nuclear material (SNM), Pu-based neutron-gamma sources, with encouraging results. These results show that the ATMFD system, in its current configuration, is capable of locating the direction of a radioactive source to within 30° with 80% confidence.


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