Engineering topics
Chutjian, A.
Publications and source records attributed to Chutjian, A..
Experimental Cross Sections for Excitation of the 2s(sup 2)S 2P (sup 2)P Transition in C(sup 3+)
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Measurements of Absolute, Single Charge Exchange Cross Sections of H(sup +), He(sup +), and He(sup 2+) with Water and Carbon Dioxide
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Lifetimes of the 2s(sup 2)2p (sup 2p)(sup 0) - 2s2p(sup 2) (sup 4)P Intercombination Transistions of C(sup +)
Radiative Eistein A-values have been measured for fine structure transistions in the intercombination 2s(sup 2)2p (sup 2p)(sup 0) decay in C(sup +).
Measurements of Absolute, Single Charge Exchange Cross Sections of H(sup +), He(sup +) and He(sup 2+) with H(sub 2)O and CO(sub 2)
Absolute measurements have been made of single electron charge exchange cross sections of H(sup +), He(sup +) and He(sup 2+) in H(sub 2)O and CO(sub 2) in the energy range 0.3 - 7.5 keV/amu.
Orient and Chutjian Reply
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Miniature Quadrupole Mass Spectrometer Array
JPL is funded by Code U to develop a Miniature QMSA for an EVA flight test. The initial intent was to fly an experiment internal to the astronaut suit during a shuttle EVA. Following discussions with JSC the suit application was abandoned in favor of other more urgent needs. The JSC EVA office was particularly interested in hydrazine detection on the astronaut suit. While discussing and exploring the implementation of such an experiment, managers at JSC suggested combining the interests of two JSC groups. The Life Support and Thermal Systems Branch, Crew and Thermal Systems Division has a need for an ammonia detection instrument, while the EVA office has a need for hydrazine detection. The two groups were pursuing separate single-purpose solutions. Instead, the JPL QMSA offers a single instrument solution via a portable instrument to be used by an astronaut on an EVA. Such an instrument would serve both the ammonia leak detection and the hydrazine contamination needs. The need for the QMSA was defined as urgent and targeted for a January 1999 flight. While the original JPL task (as funded by Code U) was for an experiment flight with JPL delivery in October 1998, this task was for a qualified flight instrument with a planned JPL delivery in August 1998. This schedule was very demanding and dictated a fast-tract implementation.
Experimental Cross Sections for Excitation of the 2s S-2 yields 2p P-2 Transition in C(3+)
Experimental cross sections are presented for excitation of the 2s yields 2p transition in C(3+). Use is made of the energy-loss method with merged beams. Also described is use of a multipole "electronic aperture" to discriminate against elastically-scattered electrons. Comparisons are made with previous experimental energy-loss and optical-emission data, and with results of several theoretical calculations.
Ultralow Energy Electron Attachment at Sub-Millielectron Volt Resolution
The technique of rare-gas photoionization has been extended by use of direct laser ionization to electron energies epsilon in the range 0-100 meV, with a resolution Delta(epsilon) of 0.4-0.5 meV (FWHM). Tunable UV light at (Lambda)276 nm is produced using a pulsed Nd:YAG laser and nonlinear mixing techniques. The beam is frequency tripled in a pulsed jet of xenon. The VUV radiation, tunable at (Lambda)92 nm, is then used to photoionize Xe at its 2P(sub 1/2) threshold (single-photon ionization). The photoelectrons produced interact with admixed target gas to generate negative ions through the s-wave capture process. Recent results in electron attachment to SF(sub 6) will be reported which show resonance structure at the opening of the ground-state vibrational channels. This structure corresponds to the process of vibrational excitation + attachment, which is superimposed on the underlying s-wave (direct) capture process. It should be a general phenomenon, present in a wide variety of zero-energy electron attaching molecules.
Recent Applications of Gaseous Discharges: Dusty Plasmas and Upward-Directed Lightning
Intriguing phenomena have been recently observed in gaseous discharges which involve dust particles, and discharges which are produced in the ionosphere involving formation of upward-directed lightning.
Electron Excitation Cross Sections for the 3s(sup 2)(sup 2) 3P 3s3p(sup 3) (sup 5)S Transition in S(sup 2+)
Experimental and theoretical collisional excitation cross sections are reported for the 3s square 3p- 3s3p cube 5S to the zero spin-forbidden transition in S square+.
Electron Excitation Cross Sections for the 3s(sup 2)3p(sup 2)(sup 3)P -->3s3p(sup 3) (sup 5)S(sup o) Transition in S(sup 2+)
In the experimental approach, use is made of the electron energy-loss method with merged electron and ion beams.
Electron-Ion Collision Studies Using the Caprice 14.0 GHz ECRIS
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Electron-Ion Collision Studies Using a 14.0 GHz ECRIS
A new 14.0 GHz electron-cyclotron resonance ion source, the so-called Caprice source, has been in operation at JPL/Caltech for over a year.
Experimental Cross Sections for Electron Exitation of the 2s (sup 2)S 2p - (sup 2)P Transition in C(sup 3+)
Experimental cross sections are reported for electron excitation of the allowed 2s (sup 2)S 2p - (sup 2)P transition in C(sup 3+).
Absolute Cross Sections for Electron Imact Excitation in SIII
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Reply to the Comments of Chu et al. on O.J. Orient and A. Chutjian, in Physical Review Letters 74, 5017 (1995)
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Low-Energy Electron Collisions with Multiply-Charged Positive Ions
Cross sections for a variety of electron-ion collision phenomena are the backbone for understanding energy balance in high electron temperature plasma.