How's the new tungsten cathode working out?

[meemoe_uk]

this is just my idle speculation : I thought the goldilocks bake out plan was a bit weak. I didn’t understand why they didn’t just strip out the mylar, do a high temperature bake, then put it back together. They’d just taken FF1 to pieces to get it coated with titanium nitride weeks before, but now another disassemble was not considered for an optimal bake out?

I’m guessing based on my interpretation of the info in the reports, the goldilocks plan may not have succeeded. Just being skeptical as all scientists should be + its fun to guess !

[meemoe_uk]

I’m glad goldilocks is finished. Porridge and honey for breakfast this week to celebrate? That may have been one of the longest bake-outs in history. By comparison I could bake vegetables and fruit in my microwave oven in 2 minutes with the touch of a button back in 1990.

I expect progress at Lawrenceville will be faster now, and hope you get big results soon.

[bcreighton7]

bcreighton7 wrote: “The problem, we concluded, was that during each shot the inner layer of the steel, facing the plasma, was heated by the plasma to about 1000° C, enough to break up the chromium oxide in the stainless steel. Chromium oxide protects steel from further oxidation (rusting) at room temperature, but can’t withstand high temperatures, even for the few ms until the heat dissipated through the bulk of the steel.”

I assume an alloy like Hastelloy N has been rejected as not being as heat tolerant? Still with only 6-8% Chromium it should reduce the problem. Perhaps would accept a titanium coating better? I don’t know much about the properties of all the possible different alloys, but hastelloy N is a preferred choice for its resistance to oxidation at high temperatures.

Perhaps a relatively cheap solution would be a SiC coating? Higher melting point than SS. Doubt it could be done on site however. Would probably have to send in the chamber to be coated by a company like Electro-Coatings. They have a specialty coating they call Nye-Carb.

Then there is our friend CNT – perhaps it could be installed as a layer of conducting insulation to conduct heat away from problem areas. Don’t know how expensive that would be or if it would work better than a titanium coating – of course you need a place to conduct heat to.

P.S. If one of my suggestions is adopted, do I get a consultation fee? 🙂

For future reference my friend CNT is back in the news. It seems when utilized with nanophotonic crystals, they can convert 1000 C heat into light usable by photovoltaic cells. Perhaps covering some of the chamber walls with this material would be another way to use the excess heat to increase efficiency, while keeping critical components of the chamber cooler.
Here is a link: http://phys.org/news/2016-05-solar-usable-cell-efficiency.html

[Andrew Palfreyman]

I am getting the newsletter but there seems to be no way to share it with friends, except by email. There is no URL included.

[Anonymous]

You mean this thing?

http://us8.campaign-archive1.com/?u=87935f5eb37481cdcd48cf498&id=c7c57a3617

Also, Mr Lerner’s presentation in Prague is available as a video:

https://vimeo.com/172654207

The recent results seem very promising. Hope that I^4 scaling is acquired soon.

Onward to p+B11 !

[Joeviocoe]

bcreighton7 wrote:

For future reference my friend CNT is back in the news. It seems when utilized with nanophotonic crystals, they can convert 1000 C heat into light usable by photovoltaic cells. Perhaps covering some of the chamber walls with this material would be another way to use the excess heat to increase efficiency, while keeping critical components of the chamber cooler.
Here is a link: http://phys.org/news/2016-05-solar-usable-cell-efficiency.html

Seems a bit of robbing Peter to pay Paul.

In operation, this approach would use a conventional solar-concentrating system, with lenses or mirrors that focus the sunlight, to maintain the high temperature

You can double the efficiency of the photovoltaic cell, but need to take up probably 10 times more surface area with mirrors to reach those temperatures. It really isn’t more efficient by area of the system. It may be a cost benefit, if the material is so much cheaper than the equivalent area of regular photovoltaics.

[Author]

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