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Volume 25 (1977)
- Issue 4 Pages 263-
- Issue 3 Pages 199-
- Issue 2 Pages 117-
- Issue 1 Pages 1-
Volume 25, Issue 3
Displaying 1-7 of 7 articles from this issue
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I.Historical Survey of the Study of Gas Phase Ion-Molecule ReactionsKenzo HIRAOKA1977 Volume 25 Issue 3 Pages 199-210
Published: September 30, 1977
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1705K) -
Itsuo Katakuse, Takekiyo Matsuo, Hiromitsu Nakabushi, Hisashi Matsuda1977 Volume 25 Issue 3 Pages 211-215
Published: September 30, 1977
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA High efficiency ion source which produces low energy ions(100∼500eV)is described. In order to prevent the decrease of ion intensity due to low accelerating potential, negative high voltage is applied to the main slit. Ions are first accelerated to several thousand volts and then decelerated to several hundred volts af ter passing through the main slit. Almost the same ion intensity was obtained compared to ordinary ion source with high accelerating potential. The decrease of resolving power due to low accelerating potential was negligible when the ion source was attached to a double focusing mass spectrometer of second order. This type of ion source is useful for mass analyses of very heavy organic compounds, because very strong magnetic field is not required.View full abstractDownload PDF (469K) -
R.D. Russell, T.K. Ahern1977 Volume 25 Issue 3 Pages 217-221
Published: September 30, 1977
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSWe observed transients during the isotopic analysis of carbon dioxide, which could not be attributed to mixing processes because of their asymmetry, and to explain these we were led to consider the effects of diffusion on gas flow in the sample line. In particular, we investigated the propagation by diffusion of a concentration anomaly against a steady gas flow. If fractionation of isotopic(or chemical)species at the leak is to cause a change with time of the composition of the gas in the sample reservoir, then the effects of the fractionation must diffuse backwards as far as the gas reservoir.Using a one-dimensional Green's function, we obtained explicit analytical functions for the steady state concentration variation along a connecting tube between the leak and the reservoir, and for the composition variations with time at the leak. It is shown that the isotopic composition in the sample reservoir need not vary with time, even with a fractionating leak, provided that bulk gas velocity in the connecting tube is large enough. It is also shown that the diffusion process in combination with a fractionating leak can lead to the type of transients we observed.View full abstractDownload PDF (486K) -
Isao H. Suzuki, Kogoro Maeda1977 Volume 25 Issue 3 Pages 223-232
Published: 1977
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIonization efficiency curves have been measured for the ions including CH2+ produced from acetylene by monoenergetic electron impact over ranges of about 10 eV near their appearance thresholds. The total ionization of ficiency curve shows breaks at the energies in agreement with the ionization potentials determined by photoelectron spectroscopy. Other breaks in the curve were found to correspond to autoionizing states. The appearance potential of C2H+ almost agrees with that by photoionization mass spectrometry. The potentials of other fragment ions are not always close to those by previous electron impact experiments.View full abstractDownload PDF (972K) -
Ethylamine as a Model Compound for the α-CleavageHideyuki Konishi, Hisao Nakata1977 Volume 25 Issue 3 Pages 233-242
Published: September 30, 1977
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe electronic structures of ethylamine and the related species have been calculated by means of the INDO method to examine the scope and limitations of the so-called fragmentation rules in organic mass spectrometry. Both the unpaired electron in the molecular ion and stabilization by the conjugation in the reaction transition state are confirmed to play important roles in fragmentation reactions. Localized MO representation of the reaction transition states and applicability of bond indices are also discussed.View full abstractDownload PDF (1003K) -
Tadashige Azami, Susumu Tajima, Tamae Yanagisawa, Takeshi Sato, Toshik ...1977 Volume 25 Issue 3 Pages 243-250
Published: 1977
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSMass spectra of ions with excess kinetic energy(KE)of several organic compounds have been measured by applying a small negative voltage to the repeller electrode. The KE mass spectra of the compounds obtained by this method are in good agreement with those obtained by other method reported.View full abstractDownload PDF (510K) -
Shunroku Taya, Hitoshi Tsuyama, Michiyasu Itoh, Ichiro Kanomata1977 Volume 25 Issue 3 Pages 251-262
Published: September 30, 1977
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSExperimental studies of solid surface analyses are carried out by means of low energy ion scattering spectroscopy(ISS)and secondary ion mass spectroscopy(SIMS) . The instrument is composed of a HITACHI IMA-2 ion probe and a stigmatic second-order double focusing mass spectrometer(electric toroidal sector: re=212mm, Φe=85°, c=0.5; uniform magnetic sector: rm=200mm, Φm=90°, ε1=32°, ε2=-10°). ISS analyses are carried out using the electric toroidal sector, while SIMS analyses employ both the electric and magnetic sectors. Primary 5 keV argon and helium ion beams are used for ISS analyses, and 8 keV oxygen ion beams for SIMS analyses. An aluminium plate, an Au-Ag-Cu alloy and a GaP crystal are analyzed. The obtained ISS and SIMS spectra are compared. The element discrimination characteristics of ISS are much more accurate than those of SIMS. Maximum mass resolving powers are obtained at30(50% valley separation)for ISS, and 11, 000(10% valley separation)for SIMS.View full abstractDownload PDF (5218K)
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