Great article on fusion by NJTV with LPPFusion included along General Fusion, ITER and Princeton Plasma Physics Laboratory.
Eric's flying to Poland for an annual DPF conference. Even though the rest of the researchers are using copper electrodes we're excited to hear the latest from everyone and to share our latest enigmas and findings. LPPFusion's Chief Scientist will be presenting on July 19. We will not be experimenting this week. Syed will be improving our diagnostic devices, focusing on the optical path for the ICCD camera. Ivy and Jose will continue with the custom database and data analytics code development.
The interview with Leah Mishkin, the correspondent from NJTV who came to the lab today, went well. She informed us that if the piece is published, it will be about 6 minutes and will include other fusion projects.
(The scope manufacturer, Tektronix, discontinued drivers in 2016.) Excel 2003 has been fully kicked out of the loop (even though we had original CDs saved.) Thanks to Jose and Ivy for 24/7 support. The new experimental procedure now includes unplugging the UPS that powers the data computer prior to each shot...lots more—in progress...
Damaged computer due to shorts this past Wednesday was replaced. We’re ready to continue experiments tomorrow. A back up scope, used, was ordered from South Korea—just in case, today. A backup data computer was built in addition to the primary replacement. We’ve got an upgraded OS. Scope drivers for the new OS (we're talking old oscilloscopes) were found after some research thanks to Texas Instruments.
This is a high voltage trace from shot 5 of June 26, 2019. This was the second to last experiment this past Wednesday, before our data computer fried (without showing any visible signs of it inside the case.) This is our highest fusion yield so far this year, 1/10th J with the #Be electrodes.
Sorry for the noise...basically the interpretation is the green line was not as wild as it looks...the possible shorts are elsewhere (chamber gas line, not shown here, is concerning...but not threatening)...The physical threats do exist, to machine and control room equipment...The IT team identified a high probability of the data computer frying despite the Faraday cage used for all diagnostic devices including the data computer...
Generally the yield trend is showing growth but it takes dozens of shots (experiments) for that trend to continue. It’s a bit of a dance: two steps forward one step back...with unknown steps in between. The images are of data on the scopes after shot 2 from Wednesday, June 26. See the next post for a bit of an "on the spot" interpretation by the chief scientist Eric Lerner.
The image is the raw data from our Far Time of Flight detector (FTF) which shows the arrival of the X-ray peak (small peak at left) and the slower neutrons (big peak at right). Vertical scale is volts and horizontal is time in ns (billionths of a second). From shot 6, June 18. The height of the big peak at right is one way we know we have more fusion yield, as we are now working with deuterium, which produces neutrons from fusion reactions.
We tracked them down and fixed them. Also, the appearance of the anode continues to evolve from shot to shot. After one shot, a horizontal line appeared on part of the anode, but then disappeared a couple of shots later. For symmetry the anode has to settle down to the same appearance—and thus the same smoothness—everywhere. This will take some time.
We’re now over 30 shots and we have tripled fusion yield over last week. Not time yet to break out champagne, as we are still a factor of 4 short of our own record yield of ¼ joule. But going in the right direction. We’ve scanned from low to high fill pressure and we have found the sweet spot for now. Improvements are still needed. For one thing, #FF2B was making too much noise when it fired—from shorts or arcs somewhere outside the vacuum chamber.
The clean-up has to proceed further to get good symmetry. We’re not sure how fast it will go, so patience, focus fusion fans! Other good news is that our new ceramic switches are functioning well, as are three new instruments: two Langmuir probes for the ion beam and an electron beam Rogowski coil.