A form of electrostatic ion trap mass analyzer, named the orbital frequency analyzer (OFA), has been developed. The ions in the analyzer are trapped around the middle plane and orbit around the central axis perpendicular to the middle plane with high-ellipticity and precessing trajectories. The orbital frequency of the ions in this device has been optimized to be independent of ions’ energy so that the image charge signal picked up by some of the field-forming circular/ring electrodes can be used to produce a mass spectrum after Fourier transform data processing. Spectra acquired by the OFA are rich of high-order harmonics, which offer higher mass resolving power than that for fundamental frequency components. The experiment shows that the resolving power is proportional to the harmonic order and exceeds 150 k for mass-to-charge ratio (m/z) of 526 Th and the transient length of 500 ms. Using high-order harmonics, an isotopic cluster of a heavy protein was resolved with a shorter transient length. The transient signals from different pick-up electrodes give different waveform shapes, and therefore, their harmonic peak distributions in a frequency spectrum are different, thus allowing the removal of unwanted harmonic peaks. The preliminary results also show a wide dynamic range of the analyzer.

Deuterium trapping by defects in W polycrystalline foils during ion bombardment was investigated by thermal desorption spectroscopy using the low fluence probe method. Probe TDS spectra showed, that there are at least 6 peaks in the region 350-900 K: at 370 K, 450 K, 530 K, 580 K, 630 K, 750 K. Experiments with as received samples showed that D is trapped mainly in low energy traps in the region 390-650 K. These defects are attributed to technological defects such as dislocations and vacancies. The peak at 750 K easily disappears when annealing the sample at about 1300 K and can be attributed to vacancy clusters. The peak at 630 K irreversibly increases at high fluence, it also appears when annealing the sample above 1300K. This peak can be attributed to voids. Voids of about 20 nm in diameter in the near surface region were observed by FIB/SEM in cases when 630 K peak was observed.

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