Scanning acceleration voltage

Accelerating voltage (high voltage) scan. An alternative method of producing a momentum (mass) spectrum in magnetic-deflection instruments. This scan can also be used, in conjunction with a fixed radial electrical field, to produce an ion kinetic energy spectrum. 

Figure 2. Repetitive scanning of m/e 310-330 (5 sec/scan). Standard conditions for this and all following figures ionizing voltage 70 eV, accelerating voltage 8 kV, trap current 300 /aA, multiplier 600, source 150°C.

Finally, the instrument can be operated in the peak-matching mode, which provides optimum mass resolving power and mass accuracy. Here the magnetic field strength is kept constant and the electric sector and acceleration voltages are scanned over a relatively small m/z range. This mode of operation is suitable when two ions that are very close in mass need to be separated or when the elemental composition of a molecule is to be determined at high resolution. 

Fig. 4 Scanning electron microphotographs of the surfaces of glassy carbon (GC) (a) and graphite epoxy composite (GEC) (b). The same acceleration voltage (10 kV) and the same resolution (100 and 10p.m) were used in both cases. Taken from [97]. Reprinted with permission...

The mass spectrum of TTX can directly be measured by fast atom bombardment- or secondary ion-mass spectrometry. In the former a JEOL JMS DX-300 mass spectrometer equipped with a JEOL JMA-3100 data system is used xenon provides the primary beam of atoms. Acceleration voltage of the primary ion is 3 kV. Scanning is repeated within a mass range of m/z 100 to 1000. 

Single-stage scanned beam accelerator with a range of accelerating voltages from 80 to 300 kV. (Courtesy of Elektron Crosslinking AB.)... 

A Philips Environmental-SEM/EDX (Phihps XL30) was used to measure the morphology on untreated and plasma-treated powders. The powders were fixed on the sample holder by double conductive adhesive aluminum tape, and then gold-coated. Secondary electron images were recorded with the scanning electron microscope (SEM) using a 15 keV acceleration voltage. 

Photomicrographs of each material were taken with a Jeol JSM-5800 scanning electron microscope (SEM) (Jeol USA Inc., Peabody, Massachusetts, U.S.A.). The photographs were taken at a working distance of 10 mm, with an accelerating voltage of 5 to 10 kV. 

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