This is actually a thing. It's called an ADSR. They're an active research topic. The big thing that they need from their beam is POWER(TM). Designs usually call for something in the ballpark of 100MW.
Note that such a concept isn't *entirely* failsafe. You can be guaranteed to shut down the fission, as there's no chain reaction, but you're not just going to make all of the radioactive daughter products disappear - they'll keep decaying and releasing heat even after you hit the "off" switch. On the other hand, because of the use of a heavy external neutron flux, you do tend to burn up waste pretty well with an ADSR - which is one of the selling points.
Thanks for the comment, Joe, particularly for commenting about power density and efficiency, which I had just wondered about in an above post. Concerning the distance needed for focusing, however, isn't that highly application dependent? I mean, how much does, for example, an ADSR really care about focus? A subcritical fuel assembly isn't exactly a small target, and your evaporation neutrons are going to radiate out in pretty much any direction regardless even if the high energy secondaries keep going roughly along the original path.
This article has got me wanting to pick up the old GEANT4 simulation I was playing around with a couple months ago....;)
They're accelerating electrons, not photons. Electrons have mass and thus never hit "light speed", as that would be a state of infinite energy, among other problems.
The article talks about linear accelerators. Which I find really interesting because that's just a stunningly high gradient for a linac. If it doesn't come at a cost of efficiency (superconducting linacs being extremely efficient accelerators, unlike say the ultracompact plasma wave accelerators that have been being researched) or power density it could be a godsend to anything that needs a high-power ion or electron source - for example accelerator-driven fission, actinide burning, general spallation neutron sources, etc. Assuming it can operate in CW mode.... Even if it can't it'd be great for medical accelerators.
Heck, with gradients this high you could be putting linacs on spacecraft as ion engines and getting some nutty-high ISP figures.
You know, right there in the abstract (don't even have to dig) is "... we conclude that the scenario most consistent with the data in hand is the passage of a family of exocomet fragments, all of which are associated with a single previous breakup event." They already have a hypothesis.
We're so awash in electric resources that we ship in aluminum ore, refine it here with local power, then ship out the aluminum;) And despite being a ridiculously windy country we only recently built our first wind turbines. There's just been no need. Heck, I'd like to see them build more if only to act as windbreaks;) Last winter my land got hit by 60m/s (134mph) winds in the strongest of the windstorms - windstorms that hit once every 2-3 days for the whole winter.
That said, I do wish they'd stop trying to dam up every river they can get their hands on. I'm all down with geo but I'm not a big hydro fan.
The amount of fuel in the tank has no bearing on the power and torque. The same issue FYI happens in rocket motors - LOX/LH has the best ISP, but LOX/kerosene is generally much more powerful, so it's common to see LOX/kerosene on lower stages and LOX/LH on upper stages. Hydrogen's very low density hurts it in the power department, even though it's a very aggressive burner and powerful per unit mass. And of course the density hits it in the range department as well.
Hydrogen adsorption materials increase range, but do so at the cost of consuming energy (at some stage or another) and increasing system mass.
Anyway, the net cycle for hydrogen combustion, or even hydrogen fuel cells, is pretty terrible from an efficiency perspective. If you're starting with electricity... stick to electricity.
That's what the original Prius was - only low speed electric. But as the AC pointed out below, if you're going to add an electric motor, you might as well add a good one, it doesn't make much of a weight difference.
I live in Iceland. In our drivers' ed books there was a section that said something to the effect of, "For a while car manufacturers experimented with adding air conditioning systems into vehicles. This generally proved to not be worth the cost and posed maintenance issues, so few do this anymore."
Here air conditioning, whether in the home or in a car, means "opening a window". Or more often just "turning down your heater" or "taking off your wool sweater".;) Large buildings sometimes have "loftræsing", but that usually just means a blower to circulate air, no chilling unit involved. The hottest it's ever been recorded anywhere in the country was 30,5C (87F); the record in Reykjavík is 26,2C (79F) A typical July day in Reykjavík has a high of 15C (59F), and people complain about the heat once you start getting close to 20C (68F).
Diesel costs $7 per UK gallon ($5.80 per US gallon). Gasoline is marginally more expensive.
I'd go with all electric. Of course, our city is trying to force everyone to bike by spending vast sums of money to rip out parking and turn 4 lane roads int A)o 2-lane with needlessly large sidewalks or B) alternating left/right turn lanes (so you have to keep switching) and packing them with stop lights for every little intersection, all for the specific design purpose of slowing down traffic to encourage people to bike instead. Oh how I wish I was kidding...
Exactly what sort of fix are you envisioning that wouldn't reduce mileage? Do you really think they're going to find room to install an AdBlue system in your car?
Unless you're talking about adding a post-treatment system, reducing emissions = lowering some combination of the combustion temperature or compression ratio = lower mileage and less power.
.. because such games are so well known for their music?
Honestly, symphonies pair well with all sorts of things, it doesn't just have to be video game music. I greatly enjoyed the pairing of the Icelandic Symphony Orchestra with Skálmöld, Iceland's best known viking folk metal band. A symphony orchestra makes anything feel more "epic".
Yeah, it's possible to design dual-purpose munitions like they did for the latest version of the javelin - a shaped charge with a casing designed to fragment so that even when not used against a vehicle (the molten copper stream), it's still quite deadly to personnel (the fragmentation).
I just can't help but picture how effective such a system would be if designed with a good target-finding system. Picture something like that targeted at, say, the Russian airbase in Latakia by some rebels who just "happened" to acquire one. Every jet and helicopter on the tarmac gets simultaneously hit with a shaped charge. Fuel tanks get hit, any exposed ammunition stocks, radar systems, control towers, communications systems, anti-aircraft batteries, vulnerable parts on tanks, unarmored vehicles... you could pretty much trash anything outdoors at the time, and what systems exactly are they supposed to use to stop it? You'll never hit a little plastic glider with a MANPAD or large SAM - and they almost assuredly cost way more than the glider (even if the glider is given a good camera and ample processing power). On the final dive it could probably hit many dozens, potentially well over 100 kmph, so good luck taking it out with small arms fire, if you even know it's coming, given that there's not going to be any noise, the radar signature is tiny, and the wings are transparent plastic. You can't jam something that's entirely self guided. Maybe you could "HERF" them, but you can't HERF an entire base without frying your own electronics as well.
Just seems like a very hard thing to defend against that could be devastating to anything not housed inside a building that provides sufficient shielding from the molten metal stream (and even such buildings might have weaknesses, with smart enough (perhaps "second generation") control software - aka looking for sufficiently large gaps such as large windows or doors, or gliders programmed to make gaps on high priority targets for later-comers to enter). A glider is never going to "fly down a narrow hallway" or anything of that nature, but say, getting into a hangar should be an achievable task. And anyway, in most situations there'd be no shortage of important outdoor targets.
If they're detecting antineutrinos from beta decay then material stockpiles should certainly show up. Tritium beta decays with a relatively short half life and has a characteristically weak decay. 240Pu (contaminant in 239Pu) spontaneous fission will create daughter products that undergo beta decay.
How exactly would that work? Antineutrinos from beta decay aren't fixed energy - the ratio of the non-gamma decay energy that goes to the electron versus the amount that goes to the antineutrino can range from 0% to 100%. There's a particular average for each radioisotope, but if you detect a particular energy antineutrino, that doesn't tell you what emitted it.
How would a single detector with global detection range let someone know that, say, Iran was running a secret nuclear reactor in some particular location it hadn't declared?
These aren't "balloon bombs", in that you're launching a balloon and hoping it goes over the right location. They talk about using a balloon to give them altitude so that they can then self-glide down to precise locations without needing an engine.
The US actively uses cluster munitions and has no plans to phase them out, and is not a signatory to the Convention on Cluster Munitions (nor are any states that could be considered its enemies or rivals, such as Russia, China, Iran, North Korea, etc). And when your control electronics completely dissolve, it's hard to picture exactly what is supposed to "set them off". Or, conversely if so designed, to not be set off when their control electronics dissolve.
Slashdot Mirror
He speech real sofistacated-like.
"shielded, shock mounted enclosures" aren't going to do anything against 1+ GeV protons.
I second the idea of dropping the Daily Mail in a bucket of tap water.
This is actually a thing. It's called an ADSR. They're an active research topic. The big thing that they need from their beam is POWER(TM). Designs usually call for something in the ballpark of 100MW.
Note that such a concept isn't *entirely* failsafe. You can be guaranteed to shut down the fission, as there's no chain reaction, but you're not just going to make all of the radioactive daughter products disappear - they'll keep decaying and releasing heat even after you hit the "off" switch. On the other hand, because of the use of a heavy external neutron flux, you do tend to burn up waste pretty well with an ADSR - which is one of the selling points.
Thanks for the comment, Joe, particularly for commenting about power density and efficiency, which I had just wondered about in an above post. Concerning the distance needed for focusing, however, isn't that highly application dependent? I mean, how much does, for example, an ADSR really care about focus? A subcritical fuel assembly isn't exactly a small target, and your evaporation neutrons are going to radiate out in pretty much any direction regardless even if the high energy secondaries keep going roughly along the original path.
This article has got me wanting to pick up the old GEANT4 simulation I was playing around with a couple months ago.... ;)
They're accelerating electrons, not photons. Electrons have mass and thus never hit "light speed", as that would be a state of infinite energy, among other problems.
The article talks about linear accelerators. Which I find really interesting because that's just a stunningly high gradient for a linac. If it doesn't come at a cost of efficiency (superconducting linacs being extremely efficient accelerators, unlike say the ultracompact plasma wave accelerators that have been being researched) or power density it could be a godsend to anything that needs a high-power ion or electron source - for example accelerator-driven fission, actinide burning, general spallation neutron sources, etc. Assuming it can operate in CW mode.... Even if it can't it'd be great for medical accelerators.
Heck, with gradients this high you could be putting linacs on spacecraft as ion engines and getting some nutty-high ISP figures.
He's not a troll, he's a likho. Putin would never employ inferior non-Russian mythological creatures!
You mean, like something broken up passing in front of the star? Which is the leading hypothesis presented in the paper?
You know, right there in the abstract (don't even have to dig) is "... we conclude that the scenario most consistent with the data in hand is the passage of a family of exocomet fragments, all of which are associated with a single previous breakup event." They already have a hypothesis.
It could also be God, slowly orbiting around the star while chatting with Jesus.
I mean, while we're here positing off-the-wall concepts like Dyson Spheres on the basis of nothing more than "a star regularly dims 20% in a cycle"...
We're so awash in electric resources that we ship in aluminum ore, refine it here with local power, then ship out the aluminum ;) And despite being a ridiculously windy country we only recently built our first wind turbines. There's just been no need. Heck, I'd like to see them build more if only to act as windbreaks ;) Last winter my land got hit by 60m/s (134mph) winds in the strongest of the windstorms - windstorms that hit once every 2-3 days for the whole winter.
That said, I do wish they'd stop trying to dam up every river they can get their hands on. I'm all down with geo but I'm not a big hydro fan.
I'd be surprised, it takes up a good bit of real estate in the vehicle...
The amount of fuel in the tank has no bearing on the power and torque. The same issue FYI happens in rocket motors - LOX/LH has the best ISP, but LOX/kerosene is generally much more powerful, so it's common to see LOX/kerosene on lower stages and LOX/LH on upper stages. Hydrogen's very low density hurts it in the power department, even though it's a very aggressive burner and powerful per unit mass. And of course the density hits it in the range department as well.
Hydrogen adsorption materials increase range, but do so at the cost of consuming energy (at some stage or another) and increasing system mass.
Anyway, the net cycle for hydrogen combustion, or even hydrogen fuel cells, is pretty terrible from an efficiency perspective. If you're starting with electricity... stick to electricity.
That's what the original Prius was - only low speed electric. But as the AC pointed out below, if you're going to add an electric motor, you might as well add a good one, it doesn't make much of a weight difference.
I live in Iceland. In our drivers' ed books there was a section that said something to the effect of, "For a while car manufacturers experimented with adding air conditioning systems into vehicles. This generally proved to not be worth the cost and posed maintenance issues, so few do this anymore."
Here air conditioning, whether in the home or in a car, means "opening a window". Or more often just "turning down your heater" or "taking off your wool sweater". ;) Large buildings sometimes have "loftræsing", but that usually just means a blower to circulate air, no chilling unit involved. The hottest it's ever been recorded anywhere in the country was 30,5C (87F); the record in Reykjavík is 26,2C (79F) A typical July day in Reykjavík has a high of 15C (59F), and people complain about the heat once you start getting close to 20C (68F).
Diesel costs $7 per UK gallon ($5.80 per US gallon). Gasoline is marginally more expensive.
I'd go with all electric. Of course, our city is trying to force everyone to bike by spending vast sums of money to rip out parking and turn 4 lane roads int A)o 2-lane with needlessly large sidewalks or B) alternating left/right turn lanes (so you have to keep switching) and packing them with stop lights for every little intersection, all for the specific design purpose of slowing down traffic to encourage people to bike instead. Oh how I wish I was kidding...
Exactly what sort of fix are you envisioning that wouldn't reduce mileage? Do you really think they're going to find room to install an AdBlue system in your car?
Unless you're talking about adding a post-treatment system, reducing emissions = lowering some combination of the combustion temperature or compression ratio = lower mileage and less power.
.. because such games are so well known for their music?
Honestly, symphonies pair well with all sorts of things, it doesn't just have to be video game music. I greatly enjoyed the pairing of the Icelandic Symphony Orchestra with Skálmöld, Iceland's best known viking folk metal band. A symphony orchestra makes anything feel more "epic".
Yeah, it's possible to design dual-purpose munitions like they did for the latest version of the javelin - a shaped charge with a casing designed to fragment so that even when not used against a vehicle (the molten copper stream), it's still quite deadly to personnel (the fragmentation).
I just can't help but picture how effective such a system would be if designed with a good target-finding system. Picture something like that targeted at, say, the Russian airbase in Latakia by some rebels who just "happened" to acquire one. Every jet and helicopter on the tarmac gets simultaneously hit with a shaped charge. Fuel tanks get hit, any exposed ammunition stocks, radar systems, control towers, communications systems, anti-aircraft batteries, vulnerable parts on tanks, unarmored vehicles... you could pretty much trash anything outdoors at the time, and what systems exactly are they supposed to use to stop it? You'll never hit a little plastic glider with a MANPAD or large SAM - and they almost assuredly cost way more than the glider (even if the glider is given a good camera and ample processing power). On the final dive it could probably hit many dozens, potentially well over 100 kmph, so good luck taking it out with small arms fire, if you even know it's coming, given that there's not going to be any noise, the radar signature is tiny, and the wings are transparent plastic. You can't jam something that's entirely self guided. Maybe you could "HERF" them, but you can't HERF an entire base without frying your own electronics as well.
Just seems like a very hard thing to defend against that could be devastating to anything not housed inside a building that provides sufficient shielding from the molten metal stream (and even such buildings might have weaknesses, with smart enough (perhaps "second generation") control software - aka looking for sufficiently large gaps such as large windows or doors, or gliders programmed to make gaps on high priority targets for later-comers to enter). A glider is never going to "fly down a narrow hallway" or anything of that nature, but say, getting into a hangar should be an achievable task. And anyway, in most situations there'd be no shortage of important outdoor targets.
That map is amazing. It almost looks too good - I hope that they didn't just "cheat" and mark known nuclear reactors.
If they're detecting antineutrinos from beta decay then material stockpiles should certainly show up. Tritium beta decays with a relatively short half life and has a characteristically weak decay. 240Pu (contaminant in 239Pu) spontaneous fission will create daughter products that undergo beta decay.
How exactly would that work? Antineutrinos from beta decay aren't fixed energy - the ratio of the non-gamma decay energy that goes to the electron versus the amount that goes to the antineutrino can range from 0% to 100%. There's a particular average for each radioisotope, but if you detect a particular energy antineutrino, that doesn't tell you what emitted it.
Unless I'm missing something...
How would a single detector with global detection range let someone know that, say, Iran was running a secret nuclear reactor in some particular location it hadn't declared?
Huh? Where did I state any of my personal views in the above? You're reading too much into things.
These aren't "balloon bombs", in that you're launching a balloon and hoping it goes over the right location. They talk about using a balloon to give them altitude so that they can then self-glide down to precise locations without needing an engine.
The US actively uses cluster munitions and has no plans to phase them out, and is not a signatory to the Convention on Cluster Munitions (nor are any states that could be considered its enemies or rivals, such as Russia, China, Iran, North Korea, etc). And when your control electronics completely dissolve, it's hard to picture exactly what is supposed to "set them off". Or, conversely if so designed, to not be set off when their control electronics dissolve.