Mass Spectrometer

Presented herein is an analysis of an exceptionally intensive central and eastern Mediterranean dust intrusion of 15–16 March, 1998. The intrusion has been associated with development of an intense cyclone over Africa. The weather and dust development processes were simulated with the Eta weather and dust prediction model. Also presented is a comparison of the model results with the Total Ozone Mass Spectrometer Aerosol Index (TOMS AI) pictures as well as with those of the surface and weather observations. The roles of the main processes responsible for the dust plume development and associated dust intrusion to the eastern Mediterranean (EM) are studied. The observation data as well as the model‐simulated parameters are jointly analyzed. The analysis also includes the data from the back‐trajectory computations. With the aid of the model‐produced dust profiles we studied the significant variation in the altitudes of the dust layers within the cyclone sectors. In the warm sector of t...

The performance of a quadrupole mass filter (QMF) generally degrades when using electrodes of circular cross section in place of mathematical ideal hyperbolic electrodes. The circular cross section of electrodes produces nonlinear resonances resulting in distortion and peak splitting in mass spectra. In addition, resonances reduce the actual working cross section, resulting in limited ion yield. In this article we study nonlinear resonances and intensities of resonance lines passing through the tip of the stability diagram of the QMF. We have found that balancing of multipole terms, rather than eliminating individual multipole terms, improves the sensitivity of the QMF considerably. The theory for assessing intensities of nonlinear resonances is presented in detail along with rescaling laws to adjust current QMF parameter settings. A general formula is presented from which the location and intensity of nonlinear can be derived, which then may be used for the design of special purpos...

The ion specie fractions of the diagnostic hydrogen beam of TEXTOR tokamak have been determined by making use of a Hα-light Doppler shift spectroscopy and alternatively by a magnetic mass spectrometer. The measurements were done for the fixed beam energy of 50 keV and beam current variable up to 2.5 A. According to the measurements, the full energy beam component is for a radio frequency plasma box ∼50% by the particle density and more than 75% for an arc-discharge plasma box.

As a part of our continuing investigations on level structures of deformed nuclei away from the stability line, we report here results of our studies on highly n-rich Np (Z=93) nuclei, against the background of our recent report on Np [1] and the earlier one on Np [2]. Presently no data is available [3] on any levels in Np or in Np. The only experimental studies [3] related to these nuclei include the transfer reaction studies on Pu targets of Flynn et al. [4] and Moody et al. [5] resulting in identification of a few levels of Np in the (t,) pick up reaction [4] and of Np (2.29 m) decay, presumably from its ground state (gs) [5]. We critically examine the suggested Np energy levels [3,4] and work out a level scheme for Np using the well tested 3-step Two-Quasiparticle-Rotor-Model (TQRM) [1,6]. The first step in TQRM formulation consists of mapping the relevant physically admissible one-quasiparticle (1qp) configuration space by a plot of the experimentally observed [3] energies of ...

During the eutectic freeze crystallization (EFC) of an industrial aqueous MgSO4 solution, ice and magnesium sulfate duodecahydrate (MgSO4·12H2O(s)) were crystallized simultaneously near the eutectic point. It was found that the crystallization was highly selective: although the industrial feed solution contained appreciable levels of inorganic impurities (typically: 320mg/LCl-, 410mg/LCa2, 40mg/LMn2+, 70mg/LNa+ and 50mg/LK+), the formed ice and salt crystals contained lower