Research of excitation processes at atomic collisions

1. Petrozavodsk State University REC “Plasma” Gavrilov S.E., Kashuba A.S., Khakhaev A.D., Kiprushkin S.A., Korolev N.A., Kurskov S.Yu., Nosovich N.G., Semin V.V. Research of excitation processes at atomic collisions

2. Problem It is known that in the atom interactions as follow A+B —>A+B*(n) with the fixed collision energy the dependence of cross sections of single electron excitation on main quantum number n in each series looks as (n)n –3. But the mean square processing of our data shows that the dependence of cross sections on n cannot be described by such law. Received data have allowed to find out, that at fixed collision energy the emission cross sections of He, Ne in spectral series depend on main quantum number as follows: (n)n –, where  characterizes serial dependence and changes in an interval from 3 up to 12.

3. Subject of inquiry and set-up In this work we report the results of the experimental research of the dependence of the emission cross sections in Ar I series on main quantum number at fixed collision energy. The cross sections for transitions between Ar (3p54s) and Ar (3p5np) states (4n6) at 450 eV collision energy (cm) are presented. The measurements of the emission cross sections at interaction of an atomic beam with a gas target were carried out by optical methods on CAMAC-based setup, controlled by computer. Experimental set-up outline is shown on figure 1. Figure 1. Experimental setup: 1 – ion source; 2 – multi-channel charge exchange cell; 3 – gas target; 4 – detector of fast atoms; 5 – optical recording system.

4. Results Ar spectrum at 450 eV collision energy

5. Results as parameter characterizing serial dependence of the emission cross sections in Ar I series (4n6) at 450 eV collision energy

6. Results

7. Resume and plans It is evident that the results for small n in Ar (as well as for Ne and He) contradict to the theoretical conceptions. It shows to the necessity of the further development of the theory of multi-electron atoms. Taking into account our early received results we can affirm that for small n value increases with increasing of atom mass and number of electrons in colliding atoms. In future we plan to research mechanism of interaction of Ar atoms by optical polarization of emitted radiation. Also, It is planed to invite physicist-theorist for development of excitation theory of multi-electron atoms.

8. Distributed information and measuring system

9. Resume • The distinct feature of the presented distributed information and measuring system is that it allows combining different device interfaces along with their control computers into uniform network functioning on the basis of TCP/IP; • It also should be mentioned that the installation and connection into the system of new research equipment appears to be very simple. Unlike in widespread systems, the addition into the system of a new device interface with connected physical equipment comes to registering the appropriate equipment server in the configuration of the communication server. After that the client programs receive access to the experimental equipment; • Besides, the transfer of the data exchange function with the client software from the equipment server to the communication server allows to greatly simplify the equipment server structure and increases the speed of running the software; • One of the advantages of the presented system is that the software controlling the experiment is running not at a remote computer (like in most web-technologies) but on the client’s computer connected to the system through the global net. Such structure and organization of the interaction in a multi-user system substantially increases its flexibility;

10. Resume • Besides, the structure of the communication server provides simultaneous access of few users to the research complexes or its subsystems. At that, the equipment used by one client is "protected" during the exchange period from other client’s intervention; • All the advantages of the presented structure are especially distinct while using the distributed system for education purposes: • First, the simplified procedure of the equipment server creation provides easy introduction of unique scientific research equipment in educational process; • Second, since control program are run on the user’s computer, user can modify theirs according problem; • Third, it is possible to organize for students not only laboratory practice tasks within limited algorithms, but also carrying out unique scientific research experiments.

11. Application of the system for research Spectrum of plasma stream of micro plasmatrone (He, 105 Pa, 750 V, 25 mA)

12. Plans • To organize secure communication in multi-user Internet/Intranet environment it is planned to to introduce cryptographic methods of data protection; • To centralize storing of experiments results it is planned to introduce database system; • To perform remote administration it is planned to develop dataware and software for standard Internet browsers; • To connect various analog sensors to this system via LAN it is planned to develop special network interface.

13. International conferences: Northern optics 2003 (16-18 June 2003, Espoo, Finland); Photonic, Electronic and Atomic Collisions: 23 International Conference on Photonic, Electronic and Atomic Collision (July 23-29, 2003, Stockholm, Sweden); 3rd International Conference on Engineering and Computer Education (ICECE) (March 16-19, 2003, Sгo Vicente / Santos, Brazil); 2-nd "International Conference on Emerging Telecommunications Technologies and Applications" and the 4th Conference on Virtual University (ICETA-2003) (September 11-13, 2003, Koice, Slovakia); Mathematics and Science Education in the North-East of Europe (September 12-14, 2003, Sortavala, Russia); And so on. Publications Total publications - 25 With students and PhD student - 21

14. Active participants

15. Acknowledgments This work was supported by • U.S. Civilian Research and Development Foundation for the Independent States of the Former Soviet Union (CRDF) (award No. PZ-013-02), and Ministry of education of Russian Federation; • Russian Foundation of Basic Research (grant No. 02-07-97503); • grant of Ministry of education of Russian Federation in field of basic research № E00-3.2-240.