[zapkitty]

Here are some numbers that Lerner-hakase tossed out during his Space Show appearance and my patella-twitching responses to a few of them are in parantheses:

50 kj pulse = 500 hz

(isn’t this supposed to be about 10 kj now? 50 kj at 500 hz gives us 25 megawtfs… )

5 mw genset @ 3 tons and 2 meters wide

(Unshielded mass? He uses 3 tons as current mass of LPPX-1 but then uses this # for mass for FFs in general use… and they will need shielding )

output 1/3 x-rays – caught by PV with thousands layers of metal
2/3 beam !

(this needs confirmed please)

[zapkitty]

zapkitty wrote: Apparently Lerner-hakase is going to be on the podcast Space Show.

Hereafter follows my personal, condensed, and intermittently reordered version of what Lerner-hakase talked about on The Space Show. In my next post I’ll discuss the numbers that were tossed out as some of them seem to be… errors?

Warning: The following is extremely zap-centric stream-of-semi-consciousness and may or may not have some hitherto undefined relationship with what Lerner-hakase may or may not have actually said on the program 🙂

(comments in parentheses are all mine and you can’t have them)

What I think Lerner said:

State of fusion: we’ve already had the LPP updates here and nothing new on the other contenders was discussed.

As for toks… lots of ostriches with heads in sand seemingly unaware that in that position their necks are stretched out very far by now.

(With apologies to Brewer and Shipley: “One tok over the line…” )

… will the fusion ban at NASA ever be lifted?

When pB&j tests start LPP won’t do much talking until iron-clad proof of boron fusion is secured.

LPP Team forgoes “breakeven” phraseology for “scientific feasibility”. That term will mean that they’ve proven that they can generate sufficient excess power to power a generator when generators are ready. Actual generator engineering will be the next step after feasibility is proven.

LPP patents will protect investors but will not enable an LPP fusion monopoly… but the investors should do well.

(very well I’d think)

Callers to the show asked about FF space applications, is FF a Polywell, why pB&j and not D+D…

Space applications:

minimum pulse rate? cooling boron might plate out between pulses?

(would be bad as plated boron wouldn’t easily be removed short of an overhaul – what’s the fuel pre-heater wattage?)

FF best as in-space drive but could power a MHD launcher w/ fuel only 1/10th mass of payload,

Talked about FF as better for robotic missions without mention of electrode core changeout…

(that would mean a disposable stage or a tug that returns for reuse…. … or multiple staged cores? contact mad scientist central 8) )

Talked about FF as power supply for bases, Mars base talk.

(what about in situ reforming of electrodes?)

[zapkitty]

Crazy Fox wrote:
Next will come direct conversion applications in aerospace with airships using electrogravitics. .

While fusion would make for better airships, fusion by itself would not solve the problems of being a light but voluminous vehicle caught in the ground/air interface… something that waterborne vessels rarely have to cope with.

And electrogravitic propulsion remains a dream.

[zapkitty]

Apparently Lerner-hakase is going to be on the podcast Space Show.

http://www.facebook.com/pages/Focus-Fusion-Society/205597630257

Given his recent hints that electrodes may require changeouts after 30 days at 5 MWe and that units operating at less than 5 MWe may be difficult to implement… it will be interesting to hear how he thinks FFs will be applicable to space under those conditions.

Hopefully by then he’ll be up LDR and LSR type radiator systems 🙂

[zapkitty]

vansig wrote: departing from all hype and conspiracy theory,

… spoilsport 🙂

vansig wrote: what’s the smallest of these reactors that produces greater than break-even?

Unknown.

vansig wrote: can an individual buy one today?

No. They claim they are awaiting patent protection before proceeding.

vansig wrote: what is the parts list and cost?

Unknown.

vansig wrote: physical size and mass?

Unknown, but by appearances not nearly as large as an FF unit.

So…

… good questions but there is a severe lack of facts or even assertions that we can even argue about 🙁

[zapkitty]

Aeronaut wrote: But hearing “lords and masters” and/or conspiracy theory is a dead give-away that somebody hasn’t done their homework about how the system works, why it works that way, and why any emerging technology needs to fit itself within that system. This doesn’t mean sell out. It means design lots of ways for existing energy providers and distributors to look good and profit more by doing the right thing in our opinion. I outlined this last year on the FaceBook discussions tab.

I mentioned no “conspiracy theory.”

I only referenced the oft-demonstrated fact of the importance of energy to the elites… and the unimportance of human lives to said same. The most recent example being several hundred thousand dead Iraqis but there have been many other examples in US history alone.

Now the plutocrats may indeed rely on the web of inertia inherent in the current infrastructure of power generation and regulation to slow down and hobble a disruptive technology… but bypassing them completely by offering a home heating and power plant solution at a fraction of the price of a new home is guaranteed to cause a rash of small plane crashes.

And your argument seems to want to have it both ways… paying toll to the oligarchs while declaring “freedom!”

Now, even I intimated that paying that toll may indeed be the only way forward… but to pay that toll while pretending that otherwise the oligarchs would just let you slide with toppling one of the pillars of their power is naively optimistic at best.

I know you envision jump starting a fusion infrastructure with a relatively small amount of money but please don’t go all talk-polyglenbeck on me and say that the oligarchs are the solution and not the problem and that the best thing i s to make more oligarchs 😉

[zapkitty]

Still smells cheesy to me, but working with the given assumptions…

Getting past the translation errors and obvious typos… apparently a standard 10 kwt “E-cat” unit can be expected to produce 3 to 3.5 kwe (an optimistic assumption given that it’s a very low grade heat source) and that 3.5 kwe would be 3.1 kwe net as it’s supposed to take ~400 watts to run the unit. The cost is supposed to be $2000 per kwt so a standard 10 kwt unit would cost $20,000 US.

So an E-cat array capable of producing 5 mwe would need 1428.57 units… call it 1429 units at a cost of $28,580,000

For comparison a 5 mwe FF unit is hoped to come in at ~$300,000 and comparative costs per kw/h are similarly disproportionate even given the varied estimates for FF.

So with these assumptions, and if the tech pans out, would the E-cat unit be better than fossil fuels? Hell yes, and on several fronts.

But in a market with multiple fusion sources working FF or Polywell units would beat E-cat easily in economics at the subdivision or town scale and up… and FF at least is aiming at the same sort of distributed market as E-cat.

Rossi steps hard on the idea of selling to the individual home market, which is good if only because our lords and masters would kill outright if they thought that was a possibility, but at these figures such micro-marketing may the only venue where E-cat could compete with FF or PW.

But it sure would be nice to have the choices, wouldn’t it? 🙂

[zapkitty]

Myself, I’d think just LPPX-1. The final objective of LPPX-1 has been defined as the validation of boron fusion and that still lies ahead.

The basic design of the experiment still holds and the new switches will be just doing what the original specifications called for.

[zapkitty]

… but combine these cables with the fully-superconducting motors also recently developed (stators and rotors both s/c) and the dream of large all-electric aircraft becomes not only feasible but practical… this includes motors 1/4 to 1/5 the size and weight of their turbine equivalents… all you need then is a suitable power source… airbus may or may not approve of what I’m currently doing to their a400m… 8)

[zapkitty]

help… I’ve invented a fusion-powered wing de-icer… 🙂

[zapkitty]

vansig wrote: ground crews can retreat to safe distance when the craft is in operation. otherwise we’d have to space anodes as close as 3cm apart, tesselating a sphere, to get shielding mass under 100t.

Caps, cooling and aux gear to drive 1400 cores… er… wouldn’t you save time, volume, and lots of money by having a few dozen cores drive the fans until ~mach 6, let straight chemical take you out of the atmosphere and then let the cores take it from there?

vansig wrote: when it comes to space, propellant cost is king.

…me being didactic again :)… constraints on the mass and volume of propellant drive launch vehicle costs… the actual cost of propellant is a negligible factor in current launches.

vansig wrote: it isn’t a fair comparison to say Falcon, etc. is cheaper, as those represent single-use vehicles and a mature technology, whereas the purpose of envisioning this is to have routine, possibly daily, surface-to-orbit and return missions. the facilities cost is amortized over many launches.

Er… The Falcon line is intended to be reusable, or in this context “refurbishable” might be better. And they intend to be able to launch as often as people can pay. A reusable fusion spaceplane only gets you so far if the ballistic launchers are cheaper from the get-go.

But kudos on referring to rockets only as a mature technology. All too many space fans think of it as a perfected technology and it is far from that… there’s still lots of room for improvement.

vansig wrote: let’s see.. 600 kN nominal but maybe 1200 kN max thrust at lift-off;
1200 kN / (100t x 9.8) = 1.2 gee. it’s like an elevator ride

Uh… your bird is carrying propellant, right? If so then gravity and drag losses would eat your lunch, your dinner, your midnight snack, your breakfast and will probably take out options on the Thanksgiving turkey. Spaceplanes actually tend to pull a bit more g’s than ballistic launch vehicles.

[zapkitty]

vansig wrote:

… Even with the most optimistic shielding estimates you still have to have over 4.2 metric tons of water with each power module in addition to the FF cores, caps, onion etc…

not quite. the power modules don’t need to be shielded from each other; so really there is just enough shielding to protect the payload and crew.

… and the people under your craft, above your craft, beside your craft, behind your craft…

Shadow shielding requires adding the operational costs of building dedicated special facilities unrelated and unattached to current cargo and passenger handling infrastructure and the need for exclusive routing in air and space will make it much more expensive than integrating a fully-shielded craft into the traffic control system.

vansig wrote: … but regardless, it seems the biggest problem to manage is heat, after all.

I think the problem is requiring ~1400 5MWe cores to do something that a Skylon or a Falcon 9 can do… and do much cheaper.

I’m still rebuilding my basic flight proposals so I’m figuratively down in the soup at the moment but I think you might be spending too much time in the upper atmosphere… how many G’s do you pull at the max?

[zapkitty]

zapkitty wrote:

With Radiations Shield Technologies Demron…

… but it’s as dense as lead.

Oooooooops… my apologies. I had looked at the wrong figure for the density..

Demron density is actually only 3.14 g/cm^3.

If the shielding scales well for greater thicknesses this would be interesting…

The halving thickness of lead is 1 cm and that of water is 18 cm so with Demron you’d get ~18x the shielding of water for only 3.14x the mass.

If 5.5 cm of Demron equals 100 cm of water then it’d be 17.27 grams per sq cm shielded vs 100 grams/sq cm for water and ~4.2 tons minimum per module becomes ~724 kilograms.

If so then arranging the cores becomes much easier as well.

[zapkitty]

QuantumDot wrote: With Radiations Shield Technologies Demron it may be possible to remove a lot of the other shielding, maybe all of it for a blanket of the stuff, which claims to be able to stop alpha particles, beta particles, neutrons, x-rays, low energy gamma which is the harmful stuff; so it seems to cover everything you need, take up less space and less mass

http://www.radshield.com/

… but it’s as dense as lead and in the amounts needed for FF applications it would be as heavy as lead.

http://www.radshield.com/pdf/RST_Livermore_Summary.pdf

http://www.radshield.com/pdf/Lead_Equivalency.pdf

Demron’s advantages are its flexibility and the claimed non-toxicity and, in thicknesses under .5 mm, it outperforms lead of similar thickness by a rather surprising margin.

But at .5 mm thickness lead shields about as well… and an FF array will need somewhat more than a half millimeter of shielding 🙂

[zapkitty]

vansig wrote: here is an article detailing scaling parameters for EHD thrusters.

http://www.wbabin.net/physics/borg1.pdf

… but energy density is still the problem. Even with the most optimistic shielding estimates you still have to have over 4.2 metric tons of water with each power module in addition to the FF cores, caps, onion etc… and both safety and cooling mean that you will not be able to squeeze all the cores into one module.

The notional N3-X in the example I cited will require over 80 MWe and it’s just a small subsonic transport (… but that’s still way better than the 400 MWe that I had originally estimated for jet-style propulsion 🙂 )

No one seems optimistic at this time about getting much over 5 MWe per core and limiting the shielding will mean that the craft will not be able to get within 800 meters of anyone or anything.

So will FF, with the parameters as currently stipulated, have a place in aviation? I believe so… a truly revolutionary place as I’ve detailed elsewhere in this thread. And the recent work on distributed electric propulsion and MHD seems to emphasize the advantages of FF and even allow the possibility of FF supersonic transports… but…

… but…

… the two turbogenerators of that N3-X and the fuel to power them will fit in a couple of standard 2x2x3 meter FF “boxes.”

I was shocked 🙂

FF has advantages. All-electric, not air-breathing, never runs out of fuel (as far as standard aircraft operations are concerned), clean and green as all get out… but power density is not one of those advantages.

In atmosphere, that is. Get one into orbit and you’d better get out of the way because it ain’t going to wait around for you 🙂

I will continue with my attempts to see where this all leads and lay out my figures here… but the curves indicate an area between supersonic and orbital where shielded FF by itself is not competitive with chemical.

And those designs I mentioned upthread that emphasized a combination of fusion and chemical for spaceplanes now make a lot more sense to me…

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