Precise determination of nonlinear function of ion mobility for explosives and drugs at high electric fields for microchip FAIMS

2015 ◽  
Vol 50 (1) ◽  
pp. 198-205 ◽  
Author(s):  
Dapeng Guo ◽  
Yonghuan Wang ◽  
Lingfeng Li ◽  
Xiaozhi Wang ◽  
Jikui Luo
Keyword(s):  
Electric Fields ◽  
Ion Mobility ◽  
Nonlinear Function ◽  
Precise Determination ◽  
High Electric Fields

Experimental determination of the dipole moments of the X(2Σ+) and B(2Σ+) states of the CN molecule

1968 ◽  
Vol 46 (24) ◽  
pp. 2815-2819 ◽  
Author(s):  
Ritchie Thomson ◽  
F. W. Dalby
Keyword(s):  
Emission Spectrum ◽  
Experimental Determination ◽  
Electric Fields ◽  
Dipole Moments ◽  
High Electric Fields

From observation of the electronic emission spectrum in high electric fields, the dipole moments of the X(2Σ+) and B(2Σ+) states of the CN molecule have been determined to be 1.45 ± 0.08 and 1.15 ± 0.08 debye, respectively. The relative signs of the dipole moments in these two states are shown to be opposite.

Zur Bestimmung des Fano-Faktors von Ge(Li)-Detektoren

1966 ◽  
Vol 21 (12) ◽  
pp. 2083-2088 ◽  
Author(s):  
Ingolf Ruge ◽  
Peter Eichinger
Keyword(s):  
Electric Fields ◽  
Fano Factor ◽  
Theoretical Limit ◽  
Exact Determination ◽  
High Gamma ◽  
High Electric Fields ◽  
Set Up ◽  
Very High ◽  
Collection Time

Within the last two years the FANO factor F for Ge (Li)-detectors, which defines the theoretical limit for the resolution in the area of spectroscopy in regard to the detector, was found out experimentally several times. The values obtained for F vary between 0.7 and 0.15. In order to find out the reasons for these variations the dependence of the energy resolution on the electric field was examined at various gamma-energies for several Ge (Li)-detectors. Even at very high electric fields (several kilovolts/cm) still a field dependence especially at high gamma-energies appeared, which could be explained in terms of charge collection time. As condition for an exact determination of the FANO factor the extrapolation of the resolution to field strength infinity is set up; with this method the value of the FANO factor for Ge (Li)-detectors, used here, was estimated to 0.20 ±0.05.

An experimental determination of the dipole moments of the X(1Σ) and A(1Π) states of the BH molecule

1969 ◽  
Vol 47 (11) ◽  
pp. 1155-1158 ◽  
Author(s):  
Ritchie Thomson ◽  
F. W. Dalby
Keyword(s):  
Emission Spectrum ◽  
Experimental Determination ◽  
Electric Fields ◽  
Discharge Tube ◽  
Dipole Moments ◽  
Optical Emission ◽  
Optical Emission Spectrum ◽  
Stark Effects ◽  
High Electric Fields

The optical emission spectrum of the BH radical produced in a discharge tube designed to give high electric fields shows Stark effects. From these, the dipole moments of the X(1Σ+) and A(1Π) states are determined to be (1.27 ± 0.21) D and (0.58 ± 0.04) D, respectively.

Atomic Spectroscopy in the FIM

1986 ◽  
Vol 44 ◽  
pp. 758-761
Author(s):  
J. J. Hren ◽  
S. D. Walck
Keyword(s):  
Electron Microscope ◽  
Electric Fields ◽  
Atom Probe ◽  
Atomic Spectroscopy ◽  
Single Atom ◽  
Statistical Sampling ◽  
Commercial Instrument ◽  
Available Technology ◽  
High Electric Fields ◽  
Field Ion Microscope

The field ion microscope (FIM) has had the ability to routinely image the surface atoms of metals since Mueller perfected it in 1956. Since 1967, the TOF Atom Probe has had single atom sensitivity in conjunction with the FIM. “Why then hasn't the FIM enjoyed the success of the electron microscope?” The answer is closely related to the evolution of FIM/Atom Probe techniques and the available technology. This paper will review this evolution from Mueller's early discoveries, to the development of a viable commercial instrument. It will touch upon some important contributions of individuals and groups, but will not attempt to be all inclusive. Variations in instrumentation that define the class of problems for which the FIM/AP is uniquely suited and those for which it is not will be described. The influence of high electric fields inherent to the technique on the specimens studied will also be discussed. The specimen geometry as it relates to preparation, statistical sampling and compatibility with the TEM will be examined.

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