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Comment Re:sunfire / in my stellerator / makes me... happy (Score 1) 96

Fast neutron cross scattering sections in the couple MeV range barely vary over more than the range of 1-10 barns

1-10 barns is, of course, by definition, an order of magnitude. There is a massive difference between 10 barns and 1 barn. Tenfold, to be precise. ;)

More to the point, you can't just combine all cross sections like that. The energy imparted from an elastic collision isn't the same as from an inelastic collsiion, which isn't the same as an (n, gamma), and so forth. Elastic collisions are particularly low energy, particularly the higher Z the target. Taking them out of the equation yields much greater differences between materials in the range of a couple MeV. The upper end of the neutron energies are "somewhat" similar (up to about one order of magnitude), but down below 6 or 7 MeV or so there's quite a few orders of magnitude difference.

Likewise, total cross sections have no bearing on the accumulation of impurities in the material. The particular cross sections are relevant not only in terms of reaction rate, but also what sort of impurities you tend to accumulate and what effect they have on the properties of the material. Which of course varies greatly depending on what exactly they are.

Integration of annealing cycles into blanket design is not brought up enough in some design studies, but is a consideration to help

It's not a side issue, it's a fundamental issue to the design of a material designed for high temperature operation under a high neutron flux.

Blanket design is extremely constrained by tritium breeder ratio to ensure more tritium is produced than used, which squeezes volume allowed to be used by coolant, ... but they have much lower neutron flux to worry about. Gen 4 reactor designs are in the 500-1000 C temperature range, exceeding in some cases what is thought reasonable for fusion blanket design. ... Blanket replacement is considerably more complex than fuel replacement in a fission reactor

Perhaps they've been heading in a different direction since I was last reading on the topic, but I was under the impression that a prime blanket material under consideration was FLiBe. Which operates in a temperature range of 459-1430C, and is its own coolant. That doesn't change what the first wall has to tolerate, but as for the blanket itself, you have no "structural properties" to maintain, and cooling is only limited by the speed that you can cycle it.

The last paper I read on the subject also suggested that for breeding purposes one needs not only beryllium (they were reporting really poor results with high-Z multipliers), but the optimum ratio (to my surprise) worked out to be significantly more beryllium than lithium. So building structural elements out of beryllium serves double purpose, you don't have the excuse of "I need to use steel because it's cheaper" - you need the beryllium either way. It's strong, low density, similar melting point to steel, but retains strength better with heat, and highly thermally conductive. Beryllium swelling from helium accumulation stops at 750C+ as helium release occurs. So pairing a beryllium first wall with a FLiBe-based blanket seems like a very appropriate option.

Please don't get me wrong, I'm not at all disputing the great amount of engineering work left to do. I'm just more optimistic that appropriate solutions will be found. Perhaps I'm just naive in that regard ;)

Comment Re:Um... not to should rude (Score 1) 356

Sure, but I bought it at the end of 2008 specifically knowing I'd run Vista on it, and my way of future proofing is as much cheaper trailing edge CPU as I can find, and as much RAM as I can afford -- especially since I'd seen our poor QA guys trying to run it on a cobbled together machine with 512MB of RAM.

It worked just fine until the machine keeled over about a year ago, but it was starting to push the memory (I was also running VMware on it).

Then I replaced with a box with an AMD FX-8320E/8 core and 16GB of RAM ... over many years I've found almost nothing future proofs a machine than what sounds like a stupid amount of RAM.

Part of the problem is I don't think "minimum specs" for a Windows machine has ever been anything but a lie. It's always required much more than MS ever claimed it should.

It still amazes me that people are still selling machines with 4GB of RAM like it was 10 years ago. That just screams of leaving people with machines with far too little resources.

Even in 2008 machines with 4GB of RAM wasn't nearly enough.

Comment Re:Surprised? (Score 1) 356

Microsoft lying about minimum requirements.
The question is why?

Honestly, when machines had 4MB of RAM, but Windows was almost useless on it ... it was assumed it was largely because they wouldn't admit to real requirements.

They've been notoriously optimistic about actual requirements for years .. including Vista.

You can likely blame marketing for trying to downplay just how much it really needed.

Comment Re:Surprised? (Score 2) 356

Boo hoo .. the multi-billion dollar corporation who spends billions of dollars annually can't maintain product releases and instead has decided the world gets to be their beta testers as they go to a shitty rolling release of incomplete software they've announced they'll force people to get.

I'm sorry, are we supposed to feel sorry because MS no longer wishes to to proper release engineering and life cycle management of their products? All so they can jam ads and analytics into our machines without our permission?

Fuck that.

Comment Re:Surprised? (Score 4, Insightful) 356

Performance wise yes with enough resources it was fine. But the oem's never sold stock systems with "enough" for the entire time vista was on the market.

Well, was that Microsoft lying about minimum requirements, or OEMs ignoring them?

Because, really, way back in the day with Windows 3.11 when machines were sold with 4MB of RAM ... it was still unusable with only one application running.

Companies have been selling Windows machines with too damned little RAM for 25 years.

Comment Re:Surprised? (Score 5, Interesting) 356

In fairness, with enough resources, Vista didn't suck nearly as bad as people said it did .. I ran it on a quad core machine with 8GB of RAM until a year ago, and it was just fine.

But Microsoft has gone from "Vista sucks and Windows 8 was kind of annoying" to "actively not trustworthy" in this -- this is saying "we don't give a crap about what you are willing to let us do, we're going to do it anyway".

Sorry, but, no way this is anything but Microsoft deciding they'll get your data no matter your opinion.

Comment Surprised? (Score 4, Insightful) 356

Is anybody surprised by this?

Microsoft has pretty clearly telegraphed they don't give a shit about what the people who own the machines want, and they're going to do whatever the fuck they want.

That Microsoft is doing this is surprising in no way to me.

Microsoft simply can't be trusted to not just do what they please here.

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