RESUMEN
In order to study the discharge process of vacuum arc ion source, make a detail description of the discharge plasma, and lay the foundation for further research on ion source, atomic emission spectrometry was used to diagnose the parameters of plasma produced by vaccum arc ion source. In the present paper, two kinds of analysis method for the emission spectra data collected by a spectrometer were developed. Those were based in the stark broadening of spectral lines and Saba-Boltzmann equation. Using those two methods, the electron temperature, electron number density and the ion temperature of the plasma can be determined. The emission spectroscopy data used in this paper was collected from the plasma produced by a vacuum are ion source whose cathode was made by Ti material (which adsorbed hydrogen during storage procedure). Both of the two methods were used to diagnose the plasma parameters and judge the thermal motion state of the plasma. Otherwise, the validity of the diagnostic results by the two methods were analyzed and compared. In addition, the affection from laboratory background radiation during the spectral acquisition process was discussed.
RESUMEN
Using the T-H solid solution made by titanium absorbed hydrogen as the cathode, the Ti-H plasma produced by the pulsed vacuum are ion source was nonequilibrium: it contained both the component of titanium and hydrogen; there existed gradient in the radiaL, the horizontal and the time. As a result, it could not be described by a single temperature. The present paper assumed that the subsystem consisting of electrons and the subsystem consisting of other heavy particles reached equilibrium respectively, meaning that the Ti-H plasma was described by the two temperatures as electron temperature and heavy ion temperature, it was non-equilibrium two-temperature plasma Using Culdberg-Waage dissociation equation to describe the molecular dissociation process in the system, using Saha ionization equation to describe the atomic ionization process, combining plasma's charge quasi-neutral condition and introducing atomic emission spectroscopy as a plasma diagnostic method which would not interfere the plasma at the same time; the temperature and the particle number density of the Ti-H plasma were diagnosed. Using MATLAB as a tool, both the titanium atoms and monovalent titanium ions' ionization were considered, and the calculated results showed that with the electtron density determined by the Stark broadening of spectral lines in advance, except the heavy particle temperature and the hydrogen number density, the Ti-H plasma's parameters could be diagnosed fairly accurately; the accuracy of the electron density values had a great effect on the calculation results; if the heavy particle temperature could be determined in advance, the temperature and the particle number density of the Ti-H plasma could be accurately analyzed quantitatively.
RESUMEN
OBJECTIVE: To assess the efficacy and safety of radiofrequency catheter ablation for verapamil-sensitive ventricular tachycardia (VT). METHODS: A total of 18 patients with a diagnosis of verapamil-sensitive VT were enrolled in this study. Radiofrequency catheter ablation was administered after underwent examinations on admission to rule out structural heart disease. the ablation catheter was placed around the left posterior intermediate septum and left anteroseptal in the left ventricular to searching for the Purkinje potential (P potential). When the Purkinje potential preceded the surface QRS by ≥ 20 ms, it was considered as an ideal target for ablation. Ablation at 25 - 35 W, 60°C was often carried out at the point where the Purkinje potential was earliest. After ablation, perform programmed stimulation to measured the effects. The patients received routine postoperative treatment and care. And the follow-up period was 3 - 6 months after discharge. RESULTS: 17 patients diagnosed as ventricular raise from left posterior fascicle and 1 patient raise from left anterior fascicle were got to the radiofrequency end point and failed to elicit ventricular tachycardia again. In this patients, the Purkinje potential advanced to the starting point of QRS 20 ms were recognized as ideal point of radiofrequency. The length as the Purkinje potential advanced to the starting point of QRS are (24.0 ± 3.5) ms. the more length, the less times of radiofrequency. No postoperative complications were noted except for 2 patients who had mild hematoma at the site of puncture. During the follow-up period, 2 patients were found to have relapsed (recurrence rate = 11.1%) and showed transient resistance to verapamil. The remaining patients had no previous history of tachycardia. CONCLUSION: With a low recurrence rate, radiofrequency ablation is a safe and efficacious cure for verapamil-sensitive VT. Despite some efficacies in the treatment of VT.