Tom Ligon wrote:Just to make sure you are aware, the comments that follow Boyle's Nebel interview continue on a second page. There are three rounds of back-and-forth between Carlson and Nebel at this time, the latest made by Dr. Nebel about an hour ago as this is posted.
This electron density measurement thing is thread drift, but heck!
I'm not up on the tech, but it is supposedly possible to do some plasma or electron density measurements with a laser beam. At the time we brought up this idea, Dr. Bussard did the calculations and determined we were a couple of orders of magnitude below the density needed for a measurment using lasers. But Dr. Nebel's hints suggest the density may now be higher, so possibly it is in the realm of lasers. That could be significantly cheaper.
When I designed the big chamber used on WB6, it had some ports at odd angles and chords intended for the future installation of such beams. If you have access to photos of the new chamber, see if there are any ports suitable for running chords or off-axis lines.
You can use masers too if the density is low. It's the frequency tightness that helps determine what the density is. Lasers are nicer because they can be swept through much
smaller volumes. If you look at the reflected power, you will get a peak when the electron plasma frequency (i.e. density) matches the incoming RF. These are really fun diagnostics to build.
I hadn't bothered Alan Boyle for an update since I'm on vacation, but also because I suspect at this point there is nothing new to tell based on what we got last time. The machine is running and they're collecting data. I'm guessing that they (Dr Nebel and company) are not really going to say much else until the peer review is over, and or the funding runs out in August and they're not bound by the government contract. Just my guess. I'll email him anyway to see if he wants to do another follow-up. The follow-up I'm really interested in though will be around the beginning of September after their contract with the government is up. But then of course, if the government chooses to renew the contract, then we might still not get any juicy details, and a contract renewal in itself could be interpreted in more than one way.
In any case, Dr. Nebel has been posting here every few days, including today, especially in the back and forth with Art Carlson. This forum has a nice search feature ... click on rnebel any place you see one of his posts, and it will find them all, something like 47 at present. He has been quite forthcoming with some of the basics of theory and practice.
His post today is under theory, the electron recirculation topic.
