Synchrotron and Free electron laser Radiation: generation and application (SFR-2018)

Time-resolved X-ray diffraction experiment investigations of ultrafast processes in BINP SB RAS Novosibirsk. Status and perspectives.

Not scheduled

15m

Conference Hall (Budker INP)

Oral X-ray structural analysis

Speaker

Prof. Boris Tolochko (Institute of solid state chemistry and mechanochemistry)

Description

Solid state chemistry studies several irreversible fast processes that require a single - bunch mode of investigation and are initiated by various external influences: detonation, shock waves, laser heating. As a result of this action, processes are initiated in the sample (adiabatic compression and heating, development of thermal stresses, increase of pressure in the local region), which creating extreme conditions (temperature of 10000 C, pressure of 1 million atmospheres), leading to irreversible structural changes associated with chemical reactions, phase transitions , the destruction of the material. These processes are so unusual, and difficult for research because of the lack of appropriate instruments, that the nature of these phenomena occurring only under extreme conditions is unknown to date. Therefore, it is extremely important to develop new installations on synchrotron radiation channels in order to uncover the secrets of nature. Only with the help of synchrotron radiation can the most effective advance in this area. Wiggler. In BINP SB RAS, for single-bang experiments, a VEPP-4 collider is used at an energy E = 4.5 GeV and a 9-pole wiggler with a field of 2 T. The current of one bunch is 20 mA. The number of bunches from 1 to 16. The length of the bunch is 78 ps. The minimum interval between bunches is 76 ns. X-ray optics. Refractive optics is manufactured by LIGA technology [ 1]. One lens consists of 150,000 microelements made of SU-8. On the VEPP-4, such lens compresses the beam 10 times. On a new source of synchrotron radiation SKIF, which began to be designed, the beam can be compressed 1000 times. Detectors. A fast one-coordinate X-ray detector was developed for single bunch experiments [ 2]. The detector enables fast recording of 100 diffraction frames with an exposure time of 73 ps, space resolution 100 micron and a periodicity of 100 ns. Thus, we can record X-ray "movies" with high time resolution, which store information about the dynamics change of structure of the object under external action. Explosion chamber. Currently, our team uses two blasting chambers in which it is possible to blast an explosive charge of 15 g and 200 g, which have diameters of 60 cm and 120 cm, respectively. At present, work has begun on the design of an explosive chamber for the charge of an explosive weighing 2000 g. Gas dynamical gun. To study shock waves, a cannon is made that has the following parameters: bullet velocity – 600 m / s, bullet diameter – 20 mm, bullet weight – 500 g. The cannon with a bullet velocity of 12 km / s is designing for study the impact of micrometeorite on the surface of a space apparatus. Methods of research. Three research methods were implemented in a single-banshee regime: the X-ray imaging, the small-angle X-ray scattering (SAXS), and the X-ray diffraction. The X-ray imaging is used to tomographically reconstruct the density distribution of detonation products during an explosion (of particular interest is the reaction zone and the structure of the detonation front) [ 3], to study shock waves and ejected products density distribution in spallation processes [ 4, 5]. Small-angle X-ray scattering is used to study the nucleation and growth of nanoparticles [ 6, 7]- the products of a chemical reaction during detonation (for example, nanodiamonds), is used to analyze the size of the particles formed during ejected in spallation processes. X-ray diffraction is used to study the change in the crystal structure of the material of the first wall of a thermonuclear reactor during the ELM discharge, simulated by laser pulse heating with parameters: E = 100 J, pulse duration 120 microseconds [ 8]. 1. Russian patent # 2572045. 2. Shekhtman, L.I., Aulchenko, et al. GEM-based detectors for SR imaging and particle tracking. (2012) Journal of Instrumentation, 7 (3), C03021. 3. Pruuel, E.R., Ten, K.A., Tolochko, B.P., Merzhievskii, L.A., Luk'Yanchikov, L.A., Aul'Chenko, V.M., Zhulanov, V.V., Shekhtman, L.I., Titov, V.M. Implementation of the capability of synchrotron radiation in a study of detonation processes. (2013) Doklady Physics, 58 (1), pp. 24-28. 4. Ten, K.A., Pruuel, E.R., Kashkarov, A.O., et al. Detection of microparticles in dynamic processes. (2016) Journal of Physics: Conference Series, 774 (1), 012070. 5. Ten, K.A., Pruuel, E.R., et al. Synchrotron Radiation Methods for Registration of Particles Ejected from Free Surface of Shock-loaded Metals. (2016) Physics Procedia, 84, pp. 366-373. 6. Rubtsov, I.A., Ten, K.A., et al. Growth of carbon nanoparticles during the detonation of trinitrotoluene. (2016) Journal of Physics: Conference Series, 754 (5), 052004. 7. Rubtsov, I.A., Ten, K.A., et al. Synchrotron Radiation Method for Study the Dynamics of Nanoparticle Sizes in Trinitrotoluene during Detonation. (2016) Physics Procedia, 84, pp. 374-381. 8. Arakcheev, A.S., Ancharov, A.I., et al. Applications of synchrotron radiation scattering to studies of plasma facing components at Siberian Synchrotron and Terahertz Radiation Centre. (2016) AIP Conference Proceedings, 1771, 060003.