Final Activity Report Summary - DAIX (Development of an innovative x-ray source)
The main objectives of the project 'Development of an innovative x-ray source (DAIX) were the following:
1. design, development, fabrication and characterisation of an innovative x-ray point source
2. development of a circuit simulation for the design of the x-pinch, including Marx bank, pulse forming line and switches
3. development of a magneto-hydrodynamic (MHD) code for simulation of the dense plasma evolution and its characteristics, i.e. expansion, magnetic and electric fields and plasma density
4. development of an analytical model for the improved understanding of the phase transitions, namely solid to plasma, at the current start
5. design, development and use of laser and spectroscopic plasma diagnostics for the experimental characterisation of the plasma formation and evolution, and
6. preparation of the conditions for the use of the x-pinch device for state of the art applications such as organic light emitting diodes (LEDs) and dense plasma characterisation.
All the above objectives were successfully fulfilled during the four years duration of the project. The incoming researchers, both experienced (ER) and highly experienced (MER), together with the outgoing researchers, the project coordinator, the academic staff and the technicians of the Technological Educational Institute of Crete, Centre for Plasma Physics and Lasers, and the partner institution, i.e. Imperial College London, collaborated in an excellent way to fulfil all project objectives.
An x-pinch device was developed as an efficient x-ray as well as an extreme ultraviolet (EUV) point source. This pulsed power device was driven by a Marx capacitor bank generator which delivered a high voltage pulse with short rise time, typically less than 50 ns. Single burst and multiple bursts of x-ray radiation having duration of 6 to 12 ns and low shot to shot jitter emission of x-rays could be generated with this machine. New optical, i.e. laser quantitative shadowgraphy, and x-ray diagnostics for time resolved and time integrated studies were developed and used in x-pinch experiments. Different wire materials, i.e. W, thermocouple, Mo, phosphor bronze and stainless steel, having a diameter of 5 to 25 µm, were used to form the x-pinch targets. Time-resolved x-ray signals showed multiple peaks in the narrow time interval after the start of the current. Plasma jets were observed in the time-integrated images directed towards the discharge axis, perpendicular to the wires. Moreover, a strong and high energetic jet was observed, directed towards the cathode, while straight narrow jet formation was observed towards the anode. The size of the source was smaller than 1 mm making it suitable for the EUV and x-ray lithography, microscopy and radiography. The x-pinch device was also found to be a suitable platform for studying plasma dynamics, radiation emission mechanisms and instability phenomena in a region of unexplored low current x-pinches. Two-dimensional MHD simulations were performed to find the plasma dynamics.
A summary report about the x-pinch device and the diagnostics was provided as part of the project. In addition, a numerical simulation for the electrical characteristics of the x-pinch device was developed in order to optimise and balance the operation of the x-pinch device. A detailed report about this simulation was also provided. Moreover, a theoretical analytical model that described the x-pinch plasma formation and the plasma dynamics was developed, accompanied by a detailed report. Complementary to the x-pinch device a miniature plasma focus device was designed, developed and fabricated as a repetitive EUV intense source. The use of the above x-ray sources for state of the art applications, such as in organic semiconductor samples research as well as in the dense laser generated plasma physics research was studied.
1. design, development, fabrication and characterisation of an innovative x-ray point source
2. development of a circuit simulation for the design of the x-pinch, including Marx bank, pulse forming line and switches
3. development of a magneto-hydrodynamic (MHD) code for simulation of the dense plasma evolution and its characteristics, i.e. expansion, magnetic and electric fields and plasma density
4. development of an analytical model for the improved understanding of the phase transitions, namely solid to plasma, at the current start
5. design, development and use of laser and spectroscopic plasma diagnostics for the experimental characterisation of the plasma formation and evolution, and
6. preparation of the conditions for the use of the x-pinch device for state of the art applications such as organic light emitting diodes (LEDs) and dense plasma characterisation.
All the above objectives were successfully fulfilled during the four years duration of the project. The incoming researchers, both experienced (ER) and highly experienced (MER), together with the outgoing researchers, the project coordinator, the academic staff and the technicians of the Technological Educational Institute of Crete, Centre for Plasma Physics and Lasers, and the partner institution, i.e. Imperial College London, collaborated in an excellent way to fulfil all project objectives.
An x-pinch device was developed as an efficient x-ray as well as an extreme ultraviolet (EUV) point source. This pulsed power device was driven by a Marx capacitor bank generator which delivered a high voltage pulse with short rise time, typically less than 50 ns. Single burst and multiple bursts of x-ray radiation having duration of 6 to 12 ns and low shot to shot jitter emission of x-rays could be generated with this machine. New optical, i.e. laser quantitative shadowgraphy, and x-ray diagnostics for time resolved and time integrated studies were developed and used in x-pinch experiments. Different wire materials, i.e. W, thermocouple, Mo, phosphor bronze and stainless steel, having a diameter of 5 to 25 µm, were used to form the x-pinch targets. Time-resolved x-ray signals showed multiple peaks in the narrow time interval after the start of the current. Plasma jets were observed in the time-integrated images directed towards the discharge axis, perpendicular to the wires. Moreover, a strong and high energetic jet was observed, directed towards the cathode, while straight narrow jet formation was observed towards the anode. The size of the source was smaller than 1 mm making it suitable for the EUV and x-ray lithography, microscopy and radiography. The x-pinch device was also found to be a suitable platform for studying plasma dynamics, radiation emission mechanisms and instability phenomena in a region of unexplored low current x-pinches. Two-dimensional MHD simulations were performed to find the plasma dynamics.
A summary report about the x-pinch device and the diagnostics was provided as part of the project. In addition, a numerical simulation for the electrical characteristics of the x-pinch device was developed in order to optimise and balance the operation of the x-pinch device. A detailed report about this simulation was also provided. Moreover, a theoretical analytical model that described the x-pinch plasma formation and the plasma dynamics was developed, accompanied by a detailed report. Complementary to the x-pinch device a miniature plasma focus device was designed, developed and fabricated as a repetitive EUV intense source. The use of the above x-ray sources for state of the art applications, such as in organic semiconductor samples research as well as in the dense laser generated plasma physics research was studied.