Transparent Electrodes for X-Ray Facility
Development of Design and Technology for Manufacturing Transparent Electrodes for GRIM Multiple-Frame Radiographic Facility
Tech Area / Field
- MAN-MPS/Manufacturing, Planning, Processing and Control/Manufacturing Technology
- MAT-ELE/Organic and Electronics Materials/Materials
8 Project completed
Senior Project Manager
Tyurin I A
VNIIEF, Russia, N. Novgorod reg., Sarov
- Los Alamos National Laboratory/Plasma Physics Applications Group, USA, NM, Los-Alamos
Project summaryThe goal of the Project is to develop the technique and to manufacture transparent (not less than 60%) and uniform over the entire area current conductive electrodes for GRIM facility on the basis of technological methods of coatication of thin-film coatings over transparent materials, existing at RFNC-VNIIEF processing departments, using magnetron method. To confirm by means of strategic and explosive experiments the adequacy of the developments to be used in multiple-frame radiography methods in experimental physics fundamental questions study, and to show the suitability of the developed technologies of transparent current-conductive coatings coatication on films and glasses in order they could be used in national economy for manufacturing electric heating surfaces.
Method of multiple-frame radiography, realized at GRIM facility has been developed and successfully used in transient processes study in RFNC-VNIIEF. This method is based on the effect of photographic emulsion sensitivity increase in electric field .
Examination showed that there is no such radiographic technique neither in Russia nor abroad. This technique can be implemented widely in high-energy density physics programs. The potential of this multiple-frame radiographic technique has been studied in two Contracts with LANL: task order N13 of February 6, 1997 and task order N37 – technical leader from LANL - Dr. Irvin R. Lindemuth.
The questions of sensitivity increase of X-ray films at the expense of using electric pulse field were put in CEA/DAM #3912/DIR task order - technical leader from France - Christian Nazet.
The main point of this technique is the following: to increase sensitivity, X-ray film is placed between two flat transparent tips to which pulse electric tension with amplitude of few tens of kilovolts is fed.
A set of X-ray film, two electrodes and two luminophor intensifying screens, placed outside the electrodes, is a recording element in multiple-frame pulse radiography technique .
X-radiation goes from the source through the object under study, absorbs in luminophor layers, where it is transformed into visible light, which goes through electrodes and exposes X-ray film.
During the experiment the object under study is X-rayed by several successive pulses of - radiation. A few recording elements (up to 10) one after another are placed on its way. Synchronously with -pulses each pair of electrodes is supplied with electric tension pulses. In this connection, sensitivity and exposing of X-ray film increases. Thus, a corresponding phase of the process is registered on each X-ray film in the moment of its maximum sensitivity.
Currently in recording element of GRIM facility metal lathes with 32 micrometers of wire thickness, maid of stainless steel are used as transparent electrodes. Grid structure of transparent electrode is put on X-ray image, degrades its quality and decreases resolution of recording system. This cuts down the area of application of multiple-frame radiography, namely, during the study of small-scale effects, that go with observed physical processes and decrease the effectiveness of using sensitivity increase effect of X-ray film.
Transparent films, thin polished quarts glasses, etc., having good transparency in visible part of the spectrum can be used as substrates for electrodes. Metals’ films and metal oxides films, applied by magnetron method, will be used as current conductive coatings.
Distinctive features of magnetron method of thin films coatication are the following [3-5]:
· High technological effectiveness of the process;
· Uniformity of the coating layer;
· High adhesion with substrate;
· Possibility of coating coatication with minimal substrate heating;
· Absence of freckles in the coating;
· Environmental safety of the technique.
RFNC-VNIIEF processing department has got a great experience in development of technique of coatication of metal, oxide, semi conducting and other coatings over various materials and manufacturing test samples of unique items with such coatings.
Institute of Detonation Physics has got many years' experience of conducting radiographic experiments, using multiple-frame radiography method, which is realized at GRIM facility.
Research and technological developments will be conducted by the team of highly skilled staff, who still specializes in problems, connected with nuclear weapons development.
This assures confidence that by RFNC-VNIIEF own efforts the goals of the project will be achieved .