Early last year, Pierre Clauzon suggested doing a unique experiment based on the work of the famous Japanese experimentalist Dr. Tadahiko Mizuno. The key difference being that the apparatus would be designed to withstand high temperatures and pressures. Professor Jean-Paul Biberian, somewhat an expert in this field helped design the apparatus and between them, they called upon their friend, subsequently an MFMP team member Mathieu Valat to engineer and construct the beautiful components you see below.
In this gallery we show the components to build the High Pressure/Temperature Mizuno Cell.
The key materials used in construction were 316L stainless steel, a 4 inches tube (sch:10S), 5mm thick laser cut plates, and non regenerated billet of teflon (fresh and uncontaminated), with a diameter of 180mm and length of 300mm.
The teflon was milled to form all the white components you see in the gallery images above. Construction in this way ensured there was a minimum of potential failure points, the lowest risk of contamination and the most flexible choice of shape we can use.
The original design was to be able to withstand pressures of 10 bar and temperatures of 180°C. The weight of the materials that this required put it out of the specification of the highly accurate scales that were to be used. So the wall thickness and length of the chamber was reduced. A scale that goes @10kg±0.1g would solve this problem once and for all but is not available to us at this time. The target operating pressure is therefore 5bar.
Initial Pressure Testing
The cell went through the pressure tests up to 7.6 bars, hence validating the intended operating pressure of up to 5 bars. The sealing system works fine with no leaks @ 7.6b.
Something that had not been considered fully before initial pressure testing was that stainless steel looses much of its resistance above 130°C. We stopped increasing pressure as soon as we had deformation of the cap (7.6b ~= 170°C).
Maximum operating parameters
Pn = 7bar MAX
Tn = 170°C
Specification of key equipment
- The current and voltage to create the plasma is provided by 2 Sorensen DCS-E PSUs
- The scales used used are SATORIUS SIGNUM 1, 6kg amplitude 0.2g precision.
- Power is assessed by a NORMA D6000 power meter BIG ONE!
- Data acquisition hardware is National Instruments NI USB-6009
- Data is logged by a computer running LabVIEW software
Key expected advantages of this approach
The higher temperature and pressure capabilities should enhance the experiment in a number of ways
- Increasing the density of plasma
- Higher momentum of plasmonic hydrogen
Principle of experimental calculations
As usual in the field of thermodynamic, we want to evaluate the difference of power input and power output. The general principle used is a phase-change calorimeter, in short it uses the change of water phase from liquid to steam to evaluate the quantity of energy generated by the system. Actually the first calorimeter that was ever invented was of this kind but using phase change of water from solid to liquid.
The scale measures the weight-loss of water that is transformed into steam using the specific heat of water. The scale needs to be precise because we derive P_out from the amount of water that is evaporated from the apparatus. Ahead of the experiement we do calibrations at different pressures and temperatures, so we evaluate the quantity of energy expelled from the system lost by convection and conduction.
On the other side power input is calculated with a power meter that define the quantity of electrical power injected into the cell using electrolysis and the heating in element.
When we create a plasma within water, the collapse of the plasma bubbles around the cathode tend to produce high velocities protonic cloud. What do we expect is that the pressure will act as an enhancer of this phenomenon, creating denser plasma and having higher velocity protons. This is also a good way to increase the temperature of the water, phenomenon that atmospheric mizuno cannot since they are limited to 100°C.
UPDATE#1 - Construction gallery and video
And here is some of the parts being fabricated.