1,511 research outputs found
Cw ion lasers pumped by electron beams
No full textWe have obtained cw laser radiation from singly ionized Hg, I, Cd, Se, and As by exciting He metal-vapor mixtures with a dc electron beam. The beam is generated by glow discharge electron guns located apart from the active medium. This is the first time that cw ion laser action has been obtained using electron beam excitation
CW laser action in atomic fluorine
No full textWe have obtained CW laser action on four transitions in the doublet system of atomic fluorine for the first time. All previously reported laser action was on a pulsed basis only. CW laser radiation was obtained when F2 or AgF was used as a fluorine donor in an electron beam pumped helium plasma. A multiline output power of 200 mW was obtained
CW silver ion laser with electron beam excitation
No full textA CW laser power of 140 mW was obtained in the 840.39 nm transition of Ag II by electron beam excitation. This electron beam excited metal vapor ion laser is capable of operating using metals with high vaporization temperatures and is of interest for generation of CW coherent radiation in the 220-260 nm spectral region
1-W cw Zn ion laser
No full textWe have obtained 1.2W of cw laser power on the 4911.6- and 4924.0-Å transitions of Zn II by exciting a He-Zn gas mixture with a dc glow discharge electron beam. In addition, 0.25-W output power has been obtained on the 6149.9-Å line of Hg+ using the same excitation scheme. The combination of electron beam ionization of rare gas atoms and subsequent charge transfer excitation to metal ion levels is shown to have the potential of significantly increasing the efficiency of ion lasers. cw multiwatt visible and ultraviolet ion lasers operating at efficiencies > 10-3 appear feasible using this excitation scheme
Stabilization as a CW approximation
No full textAbstractThis paper describes a peculiar property of the category of S-modules constructed by the author, Kriz, Mandell, and May: the full subcategory of suspension spectra (all of which are S-modules) forms a precise copy of the category of topological spaces. Consequently, the “classical” homotopy category of S-modules with morphisms the actual homotopy classes of maps contains a copy of unstable homotopy theory. Stabilization and stable homotopy are induced by CW approximation as S-modules. One consequence is that CW complexes whose suspension spectra are CW S-modules must be contractible
Cw iodine ion laser excited by an electron beam
No full textCW laser oscillation has been obtained on the 5760.7 and6127.5 Å transitions of singly ionized iodine in an He-I2 plasma excited by a dc electron beam
A closed manifold is a fat CW complex
No full textIn this paper, we introduce a notion of a fat CW complex to show that a
closed manifold is a regular CW complex, while it is not always the case if we
discuss about a smooth CW structure, introduced by the first author, instead of
a fat CW structure. We also verify that de Rham theorem holds for a fat CW
complex and that a regular CW complex is reflexive in the sense of Y.~Karshon,
J.~Watts and P.~I-Zemmour. Further, any topological CW complex is topologically
homotopy equivalent to a fat CW complex. It implies that there are lots of
non-manifold examples supporting de Rham theorem.Comment: 17 page
Electron beam pumped cw Se II laser
No full textWe have observed cw laser action in 15 transitions of singly ionized selenium using an electron beam to excite a He-Se mixture. The variation of the laser output power as a function of the electron beam discharge parameters is reported
Cw laser oscillations in Cd II in an electron beam created plasma
No full textA cw Cd II laser has been demonstrated using electron beam excitation. Cw laser oscillation has been obtained on six transitions of Cd 11 in a He-Cd plasma. Output power as a function of electron beam discharge parameters has been investigated
Open access self-archiving: An author study
No full textThis, our second author international, cross-disciplinary study on open access had 1296 respondents. Its focus was on self-archiving. Almost half (49%) of the respondent population have self-archived at least one article during the last three years. Use of institutional repositories for this purpose has doubled and usage has increased by almost 60% for subject-based repositories. Self-archiving activity is greatest amongst those who publish the largest number of papers. There is still a substantial proportion of authors unaware of the possibility of providing open access to their work by self-archiving. Of the authors who have not yet self-archived any articles, 71% remain unaware of the option. With 49% of the author population having self-archived in some way, this means that 36% of the total author population (71% of the remaining 51%), has not yet been appraised of this way of providing open access. Authors have frequently expressed reluctance to self-archive because of the perceived time required and possible technical difficulties in carrying out this activity, yet findings here show that only 20% of authors found some degree of difficulty with the first act of depositing an article in a repository, and that this dropped to 9% for subsequent deposits. Another author worry is about infringing agreed copyright agreements with publishers, yet only 10% of authors currently know of the SHERPA/RoMEO list of publisher permissions policies with respect to self-archiving, where clear guidance as to what a publisher permits is provided. Where it is not known if permission is required, however, authors are not seeking it and are self-archiving without it. Communicating their results to peers remains the primary reason for scholars publishing their work; in other words,
researchers publish to have an impact on their field. The vast majority of authors (81%) would willingly comply with a mandate from their employer or research funder to deposit copies of their articles in an institutional or subject-based repository. A further 13% would comply reluctantly; 5% would not comply with such a mandate
- …
