Paperburn:
I am working on a review of that paper right now. The review is about 40% done. Writing is tough because I need to learn allot about Langmuir probes. Here is what I have so far:
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Introduction:
This work is somewhat of a duplicate of their 2010 paper. That paper proved that the field captures electrons [17]. A small Teflon polywell was placed inside a chamber next to an emitter. Electrons were sprayed at the polywell. When the polywell was switched on, the electrons were caught. This was proven by detecting them with a probe. The probe saw the voltage go negative indicating that electrons were there. This no surprise, it has been shown by professionals and amateurs before [2, 32, 30]. The results also showed that capture peaked at an ideal magnetic strength. This makes sense. It hints that the machine may be tunable. The polywell may have modes of operation.
The team is back. They have a new polywell. They also have a better probe. This probe is biased. It allows them to answer 3 new questions about the electrons. First, are they there? Second, what is their density? Third, how much energy do they have? This last question is vital. Ideally, the electrons would maintain the energy they were trapped at. These are called monoenergetic electrons [31]. In practice, the electrons bump together and radiate their energy. What results: are thermalized electrons. Measuring the ratio of these two types is critical. This the thermalization ratio.
Biased Probe:
In 1923, researchers found a new way to test plasma [33]. They stuck a thin wire into the cloud. As the positive and negatives touched the metal, a current is drawn from the wire. This became a Langmuir probe [36]. They biased this wire against ground. As the wire voltage changed from negative to positive, the current changed. This signal is known as the current-voltage (IV) curve. From this signal: the plasma density, energy, charge and potential can be found [37].
This is valuable information, but reading this signal is hard [34]. You need to convert the IV curve into the electron energies. This conversion is so complicated, that it is its’ own field of study. Conversion is done on a case by case basis. It depends on the plasma type and probe used. Normally, a computer will do it for you [35]. But the team could not pay for fancy tools or software. Their probes and analysis were homemade. The case they dealt with was: a low-density, all electron plasma being probed by an infinitely long cylinder.
Analysis:
Fortunately for the team, someone has already solved this problem. That someone was Nobel Prize winner Irving Langmuir [XXX]. Langmuir developed math to convert data from the probe into the energies he wanted. His wire probes were modeled as infinite cylinders. Around this cylinder is a sheath. Sheath behavior comes in two types. The behavior changes, depending on the wire voltage and the local voltage. When the wire is positive against this local voltage, the sheath acts a certain way. When it is negative, it behaves differently. Each case is described below.
1. The wire is positive. The wire is positive against the local voltage. Here, electrons cluster around the wire. They are attracted to the positive charge. The sheath is filled with electrons - and all of them touch the wire. The sheath goes as far as the wire’s field can reach [XXXX].
2. The wire is negative. The wire is negative against its surroundings. Here, electrons are repulsed. Any negatives touching the wire must overcome a repulsive field. To do this, they need a minimum velocity. This velocity can be estimated. It is shown below.
Using each case, Langmuir was able to find the total current to the wire. This was done with math. This led to a general equation for all wire probes in plasmas. This can help convert probe data into the electron velocities. Because it is general, it still needs to honed, to be used. You must adjust it for different situations. For example, the equation changes for probes in a normal cloud or under the spray of ion beams. This adjustment is done by modifying the velocity distribution. This process is shown later in the post.
Aluminum Polywell:
These experiments were done with a new Polywell. This device is about the size of a coffee cup. We estimated the device size using photos [23]. It had half inch thick rings, each roughly 2.25” in diameter. The rings were smooth aluminum shells, with 15 coils of coated copper wire inside. The smooth surface is critical for success. The shells were made by metal spinning [17]. A thin disc of soft aluminum is centered on a lathe. The disc is spun at high speeds. A wedge is pressed into the metal. As it spins, the metal curves around the wedge [22]. This is an inexpensive way to make the device. A photo is shown below.
The shells must be assembled to make the rings. Assembly is shown here with ties and solder. During experiments, ties or clamps were used to hold the rings together [27]. During peak use, each ring was pushed apart with 15 pounds of magnetomotive force. This is estimated in the appendix. The clamps pierce the stream of recirculating electrons. This creates problems [29]. Electrons that touch the clamps could be lost. Losses are mitigated because the clamps and the rings are at the same voltage, but this is not a perfect solution.
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Is anyone else working on this paper? Also, has anyone seen this paper from May 23rd from Turkey:
"Preliminary Results of Experimental Studies from Low Pressure Inertial Electrostatic Confinement Device" J Fusion Energy DOI 10.1007/s10894-013-9607-z