NIF

[JohnFul]

I spent the day Thursday out at NIF (they're a customer). I was able to go on a walkthrough inside laser bays and also some of the onsite manufacturing facilities. I never before really realized how small the targets actually are.

The laser technology was interesting, but certainly not state of the art. It was a "best of the 80's" sort of thing. The bay is two football fields long. Each of the 192 lasers start life in the IR spectrum. Repeated amplifiers and passed through plant food lenses (kdp or Potassium dihydrogen phosphate) serve to increase the power and transform the beam to the UV spectrum. By the time the lasers are focused on the target, you have 1.8MJ in the UV range for about a microsecond. Very cool stuff. I was able to get a selfie standing next to the Dante detector which is attached to the target chamber and was also a backdrop in the latest Star Trek movie.

NIF was recently in the news for obtaining unity in their recent DT fusion shots. In this case, unity doesn't mean the power input into the system = power out put. It means the power of the lasers actually hitting the target ... It doesn't account for losses generating the lasers using 80s technology. In any event. It was impressive.

J

[GIThruster]

I was able to get a selfie standing next to the Dante detector. . .

Count me jealous. I had missed the news about them making unity. I thought it was less than a year ago they finally announced they would never be able to do that, but perhaps they were talking about all the power used rather than what hits the target.

[JohnFul]

So how do you post a picture?

In any event, the recent limited success of NIF (power of light hitting the target = net power out, not the power used to generate the light in the first place ..) was apparently due to the shaping of the pulse. Over the 1us of the pulse (about 20 feet of light) you start with one bump in power, then kick it up a few times until the final large pulse. It makes me wonder if this technique has any application in Polywell.

The Dante detector is mounted to one of the ports on the side of the fusion chamber. Back in the bad old days before 1992, they used to drop a Dante detector in the hole with the bomb during underground testing. The thing would be destroyed in each test, but not before sending the data over wire to a recording device (tape back then). The one at NIF is not destroyed and reused over and over again.

The interesting thing to me was the plant food lenses (KDP). It's very soft and hydroscopic. They have tons of cameras that do nothing but take pictures of the lenses after each shot and look for defects. If too many defects are discovered, thy have to resurface the lens. THey can't do that with conventional water cooled lens grinding equipment; they use a CO2 laser instead. Muck of the time between shots consists of diagnostic checks like looking for defects in the optics and running simulations.

[MSimon]

So how do you post a picture?

You need to host it some where. Photobucket, a blog post, etc. Drop the link on a comment page here. High lite it. Use the Img tool on the comment tool bar.

Since this is not a url it should show up as a dummy:

[img]Image-link[/img]

[JohnFul]

The Dante Detector is behind the rail to my left.

[ladajo]

Hey!
You are not the John Fuller I know!