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Full-Text Articles in Physics
The Effects Of Surface Modification On Spacecraft Charging Parameters, Amberly Evans Jensen, Jr Dennison
The Effects Of Surface Modification On Spacecraft Charging Parameters, Amberly Evans Jensen, Jr Dennison
Graduate Student Publications
Charging of materials by incident radiation is affected by both environmental and physical conditions. Modifying a material’s physical surface will change its reflection, transmission and absorption of the incident radiation which are integrally related to the accumulation of charge and energy deposition in the material. General arguments for incident and emitted photons, electrons and ions are considered. An optical analysis of the effects of surface modification on spacecraft charging parameters on prototypical polyimide Kapton HNTM and Cu samples is presented. Samples were roughened with abrasive compounds ranging from 0.5 to 10 μm in size, comparable to the range of incident …
The Second Annual Space Weather Community Operations Workshop: Advancing Operations Into The Next Decade, Jennifer L. Meehan, Jared Fulgham, W. Kent Tobiska
The Second Annual Space Weather Community Operations Workshop: Advancing Operations Into The Next Decade, Jennifer L. Meehan, Jared Fulgham, W. Kent Tobiska
Graduate Student Publications
No abstract provided.
Workshop Addresses Aviation Community, Jennifer L. Meehan, Joseph Kunches
Workshop Addresses Aviation Community, Jennifer L. Meehan, Joseph Kunches
Graduate Student Publications
No abstract provided.
The Density Factor In The Synthesis Of Carbon Nanotube Forest By Injection Chemical Vapor Deposition, Robert W. Call, C. Read, C Mart, T. C. Shen
The Density Factor In The Synthesis Of Carbon Nanotube Forest By Injection Chemical Vapor Deposition, Robert W. Call, C. Read, C Mart, T. C. Shen
Graduate Student Publications
Beneath the seeming straight-forwardness of growing carbon nanotube(CNT) forests by the injection chemical vapor deposition(CVD) method, control of the forest morphology on various substrates is yet to be achieved. Using ferrocene dissolved in xylene as the precursor, we demonstrate that the concentration of ferrocene and the injection rate of the precursor dictate the CNT density of these forests. However, CNT density will also be affected by the substrates and the growth temperature which determine the diffusion of the catalyst adatoms. The CNT growth rate is controlled by the temperature and chemical composition of the gases in the CVD reactor. We …
Approximation Of Range In Materials As A Function Of Incident Electron Energy, Gregory Wilson, Jr Dennison
Approximation Of Range In Materials As A Function Of Incident Electron Energy, Gregory Wilson, Jr Dennison
Graduate Student Publications
A simple composite analytic expression has been developed to approximate the electron range in materials. The expression is applicable over more than six orders of magnitude in energy (<; 10 eV to >; MeV) and range ( 10-9-10-2 m), with an uncertainty of ≤ 20% for most conducting, semiconducting, and insulating materials. This is accomplished by fitting data from two standard NIST databases [ESTAR for the higher energy range and the electron inelastic mean free path (IMFP) for the lower energies]. In turn, these data have been fit with well-established semiempirical models for range and IMFP that are related to …