The publication provided below is concerned with showing how we can reduce the energy of particle beams injected in tokamaks while actually improving the performance. The trick is that the reduced energy, i.e., beam voltage, must be accompanied by an increase in the beam current. This allows a larger number of lower energy particles to…
The venerable Water Displacement, Formula #40, more generally known as the WD-40 that comes in a distinctive blue and yellow spray can, is much more than just a chemical that we spray on squeaky things. The WD-40 Company is renown for achieving incredibly high levels of employee engagement and professional satisfaction in their work. Chief…
This is a Blast from the Past posting salvaged from the embers of my old website. Over the holiday weekend we had a family dilemma. Everyone wanted to play Clue, but no one wanted to go out in the holiday traffic to purchase the game. Fortunately, we found two people willing to walk to a…
In this topic we will calculate the capacitance of a system of concentric cylindrical shells. The next figure presents the geometry of this topic. Two conducting and concentric cylindrical shells, infinitely long, constitute a system that some capacitance, C. Begin by noting that we can only determine the capacitance per unit length, C/L, because the…
A charged particle that is accelerating emits radiation. Through the study of electrodynamics we often encounter moving charged particles without considering the issues of radiation. For example, the energy of a collection of charges may be calculated in part by solving for the energy involved in bringing those charges together from infinity. Radiation that they…
Our lab, the DIII-D National Fusion Facility, has ended its experimental campaign and entered into a nearly one year period of upgrade construction. This means there will not be any new data until some time in the middle of 2019. That 2019 data, however, is going to come from a variety of new experiments that…
I have made a fair number of Langmuir probes during the time I have been running experiments for my thesis. Some of the plasma facing material is aluminum, which I used because it was easy enough to machine that I could do it myself. The benefit of being able to do this myself is that…
One of the many mathematical techniques that are useful in the study of electrostatics is called the separation of variables method. This topic covers the application of this method to a situation in which the electrostatic potential in a spherically symmetric system is known. In such a system, the potential (potential and electrostatic potential are…
It is not intuitively obvious how an object’s magnetization relates to the magnetic field it generates. To develop a better physical picture of this phenomena consider an object with a given magnetization and then solve for the resulting magnetic field, B. A cylinder of radius, R, and length, L, in which R << L (i.e.…
When IDL released version 6.3 they included a function called BUTTERWORTH. This function generates the Butterworth filter function commonly used in frequency filtering of time series data. I have previously used a Butterworth filter by generating my own array. Since it is almost always simpler to use provided functions, I decided to use this new…
While serving as the newsletter editor for the U.S. Burning Plasma Organization, I implemented an Image of the Month feature intended to highlight exciting projects within the research community. Some of these described specific projects, such as the education and outreach work, while others were just curious graphics that don’t really highlight anything. An example from…
The lengthy diary that follows was originally written in 2007. Diary of a Graduate Thesis Experiment The laboratory in which I am performing my thesis work (LAPD at UCLA) is used by researchers from all over the world. Groups that are using the device for a research project receive an allotted time in which to…
Here it is, the first thing I have ever won! The frame around the bird, that is, and all I had to do was fill out a survey. The bird is displayed by my EO1 from Electric Objects. The EO1 is fundamentally a display screen, not unlike a digital photo frame, but the company adds in a…
The 58th Annual Meeting of the American Physical Society’s Division of Plasma Physics (APS-DPP) is underway and I made it into my first press release! The conference sets up a Virtual Pressroom to distribute press releases about some of the really cool results that will be presented during the conference. For example, you can read…
Exciting news came from the area of nuclear fusion energy this past week as the team from the Alcator C-Mod tokamak announced their new world record for plasma pressure. Before getting to that, please note that you can interact with the C-Mod Team during their Ask Me Anything session hosted by Reddit on Thursday, October…
