
‘Diamond-age’ of power generation as nuclear batteries developed - triplesec
http://www.bristol.ac.uk/news/2016/november/diamond-power.html
======
ChuckMcM
It would be more credible if the Cabot Institute linked the paper on their
"All Research Papers" page ([http://research-
information.bristol.ac.uk/en/organisations/c...](http://research-
information.bristol.ac.uk/en/organisations/cabot-
institute\(c0347f3a-1376-405f-aca9-7d3d008a9701\)/publications.html?page=0))
or if they described how they are getting electricity out of beta decay (is it
simple a thermo-electric generator? How much heat differential can they push?
Or is it just bodging together chunks of radioactive material in a casement
that has reasonable head conductivity and absorbs 99% of radiation.

My favorite "invention" of that form is the water heater "booster" ball.
Basically you take a kilogram of spent fuel rod, encase it in a austenitic
stainless steel ball, and suspend that bad boy in the center of your water
heater holding tank. Hot water for the next 500 years without using gas or
electricity :-).

~~~
slimsag
> My favorite "invention" of that form is the water heater "booster" ball

This sounds super cool! what happens if people e.g. go on vacation for 3
months? would it explode the heater or melt through the ball..?

do you have any other links/info about it you can give me? I'm super curious
about it. I googled moderately but I only found some seemingly unrelated
things[1]

[1] [http://www.forbes.com/sites/jeffmcmahon/2013/02/22/nasa-a-
nu...](http://www.forbes.com/sites/jeffmcmahon/2013/02/22/nasa-a-nuclear-
reactor-to-replace-your-water-heater/#7b4faf433ba3)

~~~
leeoniya
if there's any water left in that water heater after a couple hours and it
didnt explode from vapor overpressure, you'll painfully die of acute radiation
sickness.

that's the best case scenario.

~~~
ChuckMcM
You over estimate the decay heat in a kg of spent fuel. According to here [1],
a 1GW (1000MW) plant uses 100 Metric tons of fuel, so 1 kg is responsible for
1G/100K or 10Kwatts and the decay heat of spent fuel is .1% of its nominal
power level so 10K * .001 or 10 watts. If you dump 10 watts into your water
heater it will get hotter and depending on the heat insulation of the tank it
might even get to boiling. Although typically I would expect a tank to lose
close to 10W into the ambient air once the water was at temperature.

[1]
[http://www.nucleartourist.com/basics/hlwaste.htm](http://www.nucleartourist.com/basics/hlwaste.htm)

~~~
leeoniya
No argument, though it's hard to envision a scenario where [1] is not a
predetermined eventuality for any setup that would be laughably inadequate or
economically impractical.

[1]
[https://en.m.wikipedia.org/wiki/Fukushima_Daiichi_units_4,_5...](https://en.m.wikipedia.org/wiki/Fukushima_Daiichi_units_4,_5_and_6#Spent_fuel_pool)

~~~
ChuckMcM
It doesn't follow, fuel (whether spent or not), is density and dissipation
question. Each kg of fuel is generating heat, so more fuel in a smaller space
means more heat in a smaller space. Fukishima's spent fuel ponds had both
spent and fresh fuel in them (reactor 4 was undergoing maintenance) and there
was a lot of it. Spread that fuel out across say a hectare pool of water that
is 5 meters deep and it stays out of trouble.

One disposal plan called for mixing the fuel with silica to create glass
bricks. By spreading the fuel mixture to a density that was low enough to
allow the ambient air to cool it, the bricks are shelf stable for thousands of
years and not a radiation hazard (less of a risk than even natural uranium
deposits you might come across).

Many disposal plans were like this, encapsulate the spent fuel into a
container that withstands (and blocks) the radiation while conducting enough
heat to avoid changing the properties of the material over the lifetime of its
storage. Glass and austenitic stainless are both good candidates for that
material.

~~~
leeoniya
This does not really change the conversation.

The fact that spent nuclear fuel must be kept in water _at all_ until it is
sufficiently decayed to be put into dry storage _still safely away from
humans_ means it is by definition not fail safe. Water evaporates and if you
lose the ability to dissipate heat or absorb ionizing radiation, "you're in
deep shit" would be a colossal understatement. How comfortable would you be
that something on your property or in your home is one water outage or tank
failure away from irradiating your family and probably a bunch of your
neighbors. I imagine the hazmat team won't be happy to be invited to your
housewarming either.

If it requires cooling or radiation-blocking-immersion to be safe, it
absolutely _has_ to be monitored by trained personnel 24x7 who can also
immediately and reliably take necessary measures when something goes wrong.
Anything less than this is a non-starter. Nuclear reactors work because they
centralize risk to where it can be managed by a team of knowledgeable people;
A 1GW reactor does not have the same risk profile as 1000 dispersed 1MW
reactors.

~~~
ChuckMcM
But that was my point, spent fuel doesn't have to be kept in water _at all_ ,
if it is sufficiently dispersed. Take a spent fuel assembly remove each of the
fuel rods and lay them down on the ground and you're done caveat two things,
one they emit alpha, beta, and some gamma radiation and two they warm their
surroundings. So there always exists a solution to the equation of heat
generated over time = heat absorbed by ambient air keep the total temperature
rise below that of the safe temperature of the cladding.

If you lay a spent rod out on the ground in the air, it may glow (would depend
on the amount of material in a single rod) and you wouldn't want to approach
it without protection (again more material more radiation) but it would be
fine.

The reason people put these things in water is two fold, one is that water is
a great transporter of heat and you can generate almost an arbitrary amount of
heat in a small space if you have enough water flow to carry it away (ask any
highend gamer PC aficionado :-)) and water absorbs neutrons, which if they
were not caught and hit another fissile atom nearby slowly enough might spit
it, or a non-fissile atom might become an unstable nucleotide (which is going
to eventually emit an alpha or beta particle)

If the material is clad in a neutron opaque material and can transfer the
latent heat to the surrounding atmosphere or fluid at a rate that keeps the
system temperature under the breakdown temperature of the containment, then it
will be stable "forever".

Yes, it takes a year or two for the short lived nucleotides in a fuel rod
pulled from a reactor to decay, but once it has, you can safely store this
stuff.

In terms of why we haven't, most of the issues around storing high level
nuclear waste arise because third parties do _not_ want to encapsulate
permanently this material, because doing so would make it uneconomical to
recover. And in that calculus they know its "easier" to reprocess spent fuel
for bomb grade uranium and plutonium than it is to build a breeder reactor to
make it.

------
hashin
I can see that they are emphasizing on the #DiamondBattery hashtag so that
general public will be hooked and share it more, but why haven't they given
any hints (mildly technical) to the capabilities of the battery?

// A team of physicists and chemists from the University of Bristol have grown
a man-made diamond that, when placed in a radioactive field, is able to
generate a small electrical current.//

When I read the "small electrical current", the physicist in me was naturally
assuming a very small current of the order of pico to nano amperes (without
being conservative) - essentially useless. Metrics like the half life of the
battery doesn't make any sense at all if the power or current rating is not
specified. Current rating is something you could trust, that it will end up as
a viable product.

This would appeal more if they can give a direct link to their research paper.

~~~
extrapickles
Current off the shelf betavoltaic batteries produce 50-350 nA @ 2.4v. I don't
expect them to be producing much more than that.

~~~
berntb
Is that an idiom, or are they really "off the shelf" and not specially built
for every space probe?

~~~
extrapickles
They are "off the shelf" in that you can give them a call and in 6 weeks have
one. I suspect they obtain and load the nuclear material for your order, but
the rest of the device is stocked as it involves custom semiconductors which
have fairly large minimum orders.

These are the class of battery that would replace the CMOS battery in
something that can never lose power to its RAM, rather than the much more
powerful RTGs that space probes use.

~~~
aminorex
Part of a spectrum from MEMs through pacemaker batteries, Cassini-style RTG,
pebble-bed reactors, up to massive GE/Siemens style LWRs. It's a remarkably
scalable tech, both up- and down- scale.

------
roel_v
This will sound like neckbeard cynicism, but I actually mean this and in a
positive way:

"There are so many possible uses that we’re asking the public to come up with
suggestions of how they would utilise this technology by using
#diamondbattery.”

It's cool how they're engaging the public in their research in this way. Of
course it's a transparent ploy to get social media mentions, but scientists of
all sorts (and I kind of am one myself) would do themselves a favor by doing
more to get the general public to know about their/our work. This particular
thing 'feels' sort of slimy (to me at least, but I suspect to others on this
site as well), but I think that's a bad reflex on my part, and that easy, low-
friction things like giving people an opening to send a quick tweet or FB post
reaches a different audience than having a stand at the 'open science fair' or
having a lecture open to the general public; those tend to self-select in the
audience they attract, to put it mildly.

~~~
mahranch
> This particular thing 'feels' sort of slimy

I was just coming here to talk about how inaccurate the title was. It implies
(or leads people to believe) that "nuclear batteries" are something new. Or at
least, that's what they want readers thinking. They're not even close to new.
They're decades old. They're aboard the Voyager probes (which is why they're
still working, 30 years later) and they're powering the Curiosity rover on
Mars. Hell, there was even a nuclear battery powered automobile made by Ford I
believe (the "Nucleon") as proof of concept. This was in the 1950s.

The new thing here, is the fact that they can run the batteries with nuclear
waste.

~~~
x3n0ph3n3
Voyager I and II and Curiosity are powered with radioisotope thermoelectric
generators [1], which are nothing like this proposal.

[1]
[https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...](https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator)

~~~
mahranch
> Voyager I and II and Curiosity are powered with radioisotope thermoelectric
> generators

AKA a nuclear battery... That's how they're referred to by just about
everyone.

------
legulere
> In fact, diamond is the hardest substance known to man, there is literally
> nothing we could use that could offer more protection.

With such nonsense it is hard to believe the rest of the article. Heat a
diamond and it will burn releasing CO2 into the air, smash it with a hammer
and it will burst in million parts. Small particles and gasses are very easy
to ingest.

~~~
marcosdumay
> Heat a diamond and it will burn releasing CO2 into the air

I bet you have never tried that.

Heat a diamond enough (what it a lot), and it will turn into graphite (layer
by layer), a substance usually used for heat protection since is one of the
solid materials we have around that survive the hightest temperatures.

Also, hit it with a big enough hammer, and yes, it will smash. It will also
press a dent on your hammer.

~~~
joezydeco
A material can be "hard" but also be brittle. Diamond is one of these
substances. You don't need a large hammer to crack or destroy one. Ask any
jeweler.

~~~
logfromblammo
Diamond has perfect cleavage in four directions.

If you want a mineral that you can really pound on without it breaking, you
want nephrite. The Maori made war clubs out of it. Bring a diamond to a
nephrite fight, and you're going to end up in the stewpot.

If you need hardness and toughness, corundum is what you want.

------
zellyn
Sounds cool. One annoying bit of breathless (and brainless) enthusiasm stuck
out though: "In fact, diamond is the hardest substance known to man, there is
literally nothing we could use that could offer more protection."

While diamonds are extremely hard, they are brittle, and shatter relatively
easily.

~~~
hasenj
Maybe it's my lack of imagination or not having English as a native language,
but how can something be "hard" and at the same time shatter easily?

EDIT: nvm found the answer via Google

[https://www.quora.com/Why-is-the-diamond-hard-yet-
brittle](https://www.quora.com/Why-is-the-diamond-hard-yet-brittle)

~~~
tunap
Even better:

[https://en.wikipedia.org/wiki/Hardness](https://en.wikipedia.org/wiki/Hardness)

I read an enlightening discussion on HN a few months back about "hardness". I
was under the impression professional scientists/researchers do not use the
generic terms "hard" or "hardness". Outside of marketing, I presume they would
employ concise measurements like ductility, elastic stiffness, plasticity,
strain, strength, toughness, viscoelasticity, and viscosity.

------
wolfgang42
From #diamondbattery tweets:
[https://twitter.com/search?q=%23diamondbattery](https://twitter.com/search?q=%23diamondbattery)

Could be used in underground seismic monitors
[https://twitter.com/Keminoes/status/803297734694465541](https://twitter.com/Keminoes/status/803297734694465541)

Car keys that require batteries. If we don't have a spare battery with us and
our keys die, we're stranded. MP3 players, too
[https://twitter.com/tysongeisler/status/803438384052129796](https://twitter.com/tysongeisler/status/803438384052129796)

To power a low-power-mode Arduino for gas detection (CO, CO2, Low O2, etc),
fire detection, radiation detection, etc.
[https://twitter.com/noalear/status/803389146433626112](https://twitter.com/noalear/status/803389146433626112)

Could diamond batteries be used to power medical nanobots?
[https://twitter.com/weirbe/status/803418222972125184](https://twitter.com/weirbe/status/803418222972125184)

Power clothes that contain sensors, as well as clothes that electrically
regulate the temperature.
[https://twitter.com/CIMCloudOne/status/803440800759574528](https://twitter.com/CIMCloudOne/status/803440800759574528)

how about in cell phones to give a little charge to the battery while the
phone is not in use.
[https://twitter.com/W_Haas/status/803352403512872961](https://twitter.com/W_Haas/status/803352403512872961)

Is there the potential to power watches as a fair amount of waste is generated
from depleted watch batteries each year.
[https://twitter.com/Merrett72/status/803297788163289088](https://twitter.com/Merrett72/status/803297788163289088)

~~~
ComputerGuru
> To power a low-power-mode Arduino for gas detection (CO, CO2, Low O2, etc),
> fire detection, radiation detection, etc.
> [https://twitter.com/noalear/status/803389146433626112](https://twitter.com/noalear/status/803389146433626112)

Except you wouldn't use an Arduino; AVR processors are notorious power hogs
when you start counting the milli (and micro) watts. Run-of-the-mill TI MSP430
microcontrollers, aside from being arguably more powerful and better designed
at similar price points, consume less than 1 _micro_ amp in idle mode.

~~~
wyager
> AVR processors are notorious power hogs

> MSP430 microcontrollers ... consume less than 1 microamp in idle mode.

As someone who's done extremely low-power development on both platforms, this
is an _extremely_ disingenuous comparison. Of course MSP430s consume very
little current in idle mode. So do AVRs. People just don't usually run them at
low frequencies or in idle mode, because Arduino is targeted at novice users,
not people who know how to do low-level power management.

I've been running an ATTiny off the same pair of AA batteries, blinking an LED
for 50ms every 5 seconds for _4 years_. Just turn all peripherals off, maximum
clock prescaler division, sleep mode with wake on watchdog interrupt. There's
functionally no way to get better performance out of an MSP430 in real-world
applications.

While I prefer the MSP430 instruction set, beyond that there's no obvious all-
around advantage over the AVR family.

~~~
iamatworknow
>I've been running an ATTiny off the same pair of AA batteries, blinking an
LED for 50ms every 5 seconds for 4 years.

Is this just for fun or is it part of a larger project?

~~~
wyager
For fun. My parents wanted a fake security system with a blinking light at
their house to ward off burglars, so I soldered an LED and a resistor to an
ATTiny and then soldered on a double AA pack. It's still going off the first
set of batteries.

------
sandworm101
This is no diamond-age. These devices are all well and good, but think of the
scales involved. To generate enough power to do something like power a home,
let alone a vehicle, we are going to need kilos of this stuff. Kilos of
diamond. It's also going to get rather hot. That is the point.

Using numbers from patch_collector: 1 x 50watt lightbulb / 0.0013 Watts/gram =
38Kg = 83lbs of diamond per bulb.

Diamonds are far from indestructible. They shatter. More importantly, they
burn. We don't see it very often but put enough of them together, add heat and
electricity, and you better hope there isn't any oxygen nearby. Imagine a
couple pounds of these things, on fire, pumping out radioactive carbon
dioxide. At least when uranium burns it produces something heavy that can be
filtered. Filtering radioactive CO2 would be a nightmare. These things will
never find there way into any consumer product.

~~~
ryao
At what temperature does Diamond burn?

~~~
jws
Diamons will burn at 690°C in pure oxygen. Houses burn at around 590°C. Maybe
if you rupture an O₂ tank in a house fire right next to the diamond battery
you could pull it off.

I wouldn't worry about small diamond batteries. There is already 1 part per
trillion carbon 14 in you. The odd telemetry battery that gets caught in an
oxygen fire isn't going to shift the scales much.

~~~
legulere
Trash incineration is around 1000 degree Celsius. People already now throw
batteries in household trash when they shouldn't.

------
marrone12
If civilization ever falls, future generations would think using crystals for
energy must have been a fairy tale.

~~~
gallerdude
Enter Laputa.

------
tunesmith
Haha this sounds straight out of Asimov's Foundation novels where a
civilization was driven to innovate miniaturized nuclear power.

~~~
petre
Wasn't the Earth in Asimov's Foundation radioactive and unhabitable? Having
that blue glow at the horizon (ionizing radiation-induced luminescence?).

~~~
AYBABTME
The Earth was made radioactive due to a plot by the Spacers.

On the other hand, the Foundation - the civilization using miniature nuclear
reactors - is happening many millennial later and far away from Earth.

So the "miniature nuclear tech" and "radioactive Earth" aren't related in the
plot.

------
irq
Does anyone have details? Like what is the nominal voltage, power density,
etc?

~~~
patch_collector
Here's the best I can find, from Eikka's comment on Phys.org:

"Carbon-14 has a mean decay energy of 49 keV or 7.85e-15 Joules and activity
of 165e+9 bq/g which gives you a power output of 0.0013 Watts per gram.

So a gram-sized lump of carbon-14 - about half a teaspoon - assuming perfect
conversion, will produce 1.3 Milliwatts, or about 1/20th of what it takes to
light up a common red indicator LED."

[http://phys.org/news/2016-11-diamond-age-power-nuclear-
batte...](http://phys.org/news/2016-11-diamond-age-power-nuclear-
batteries.html#jCp)

~~~
Leon
That would actually be perfect for long range interstellar probes. A constant
source of energy for thousands of years, even that small, would propel a craft
to reasonably high speeds. Give a spacecraft a few pounds and you'd have
something really great.

~~~
samstave
So given that, assume you put an array of batteries together, what is the
formula for Batteries of qty=N allowing a range of Z AU comm ability to earth
/ current-AU-distance == distance-from-earth before we will not be even able
to receive said comms...??

So how far can they get on N batteries before we cant hear them?

Is there such a thing as "solar-syncronous" and "galactic-syncronous" orbit
such that we can deploy a TON of little relays that would speed up comms to
each probe to the Earth?

I.E. we have however many in a sphere around the solar system, then at some AU
distance out, that the extending probes can contact more efficiently?

Assume that the little diamond batts can only reliably transfer a signal by
AU/.00X - then we need to create grids of these little guys at AU/.00X
intervals to relay the signals within the power capabilities of the probes...

or is this a stupid thing to say?

\---

This begs the questions; what is the best method/technology for sending
messages between sensors through space?

We can still hear the Voyagers, how long do their signals take to get here?
How much data do they send? How long will their batteries last? How far until
they go dark? (they are already like 34 times as far from us as we are from
Jupiter.)

How well could these little batteries power the new EM/ION drive:
[https://www.nasaspaceflight.com/2015/04/evaluating-nasas-
fut...](https://www.nasaspaceflight.com/2015/04/evaluating-nasas-futuristic-
em-drive/)

How much power does that need?

~~~
p1mrx
If you put a radio at ~10X the distance of Pluto, you can use the sun as a
gravitational lens, and communicate with another star using milliwatts of
power:

[http://www.centauri-dreams.org/?p=10123](http://www.centauri-
dreams.org/?p=10123)

You're still bound by the speed of light, unfortunately.

------
kodfodrasz
Even if this is true I think this is such a public safety hazard, that the
authorities will never allow its public adoption.

Just think in terms of domestic terrorism and dirty bombs. Exploding a few
such batteries would release radioactive powder, which is a quite dangerous if
inhaled, and cleaning it up is very difficult.

~~~
regularfry
C14 isn't much good for a dirty bomb. It's too light. You'd probably need to
be actually caught in the explosion to stand a risk of inhaling enough to be
problematic, and at that point you've got other things to worry about.

------
nathan_f77
WOW. I always expected that we would see mobile phones that lasted for days or
weeks before needing to be recharged. I never once considered the idea that we
may have mobile phones and laptops that NEVER need to be recharged during our
lifetime. That is an incredible thought.

I wonder how hard it will be to convince people to put nuclear batteries in
their pocket. Many people are still afraid of microwave ovens.

~~~
givinguflac
It does sound incredible, but I don't think most people would be down with
carrying nuclear waste in their pockets.

~~~
nathan_f77
Many of us already carry around lithium ion batteries in our pockets, and I
think these nuclear batteries could be far less dangerous. Phones can explode
without warning, and bending or piercing a battery can cause huge explosions
and fires. You'd have to try really hard to shatter these diamonds, and they
would probably have some lead lining.

~~~
enraged_camel
Sure, it's easy to say that as an engineer since we deal with facts and data,
but the general public is anywhere from wary to extremely scared of anything
"nuclear."

------
kilroy123
I'm not sure if this will lead to a new revolutionary battery.

But I'll say this, the man/woman who creates a company that builds a new
revolutionary battery that will keep your laptop humming for a week; will be
very rich. Probably the next richest person on earth.

~~~
neurostimulant
Putting that much power density on your lap is kinda scary. It's like carrying
a slab of C4. Imagine if the galaxy note incident happen again but with a much
much higher power density battery which can go kaboom.

~~~
ccozan
How would a C14 slab would go kaboom? Its only role is to give radiation which
is transformed into heat or electricity.

I don't expect any explosive parts here.

~~~
neurostimulant
I was talking about a high capacity battery that can power a laptop for a
week, not the nuclear battery from the article.

------
outworlder
> A team of physicists and chemists from the University of Bristol have grown
> a man-made diamond that, when placed in a radioactive field, is able to
> generate a small electrical current.

So, they are replacing the thermocouples as used in RTGs with this diamond-
like stuff? And low radioactivity sources (as opposed to plutonium)? That
would indeed be revolutionary if it worked.

~~~
ars
It'll work fine, but the problem with low radioactivity sources is that they
are also low energy sources. So you need a lot of material.

------
JoeAltmaier
Suspicious: sounds like a con, in every breathless undocumented wild claim.

~~~
threeseed
Watch the language.

It's a university press release. It may not meet expectations. The science may
be faulty. They could be utterly incompetent.

But a con implies wilful behaviour on the part of the University of Bristol to
deceive people.

~~~
Dylan16807
> It's a university press release.

Which are often trying to actively deceive people, implying that tiny
iterations are new fields, and that devices are orders of magnitude more
effective than they are. I'm comfortable calling this press release deceptive.

------
drzaiusapelord
Every few years there's a proposal for a new nuclear battery. This was the
last one:

[https://www.extremetech.com/extreme/190555-this-nuclear-
batt...](https://www.extremetech.com/extreme/190555-this-nuclear-battery-
could-power-your-smartphone-forever-as-long-as-you-dont-value-your-life-or-
sperm-count-too-highly)

The problem is none of these approaches solve the disposal problem or the
dirty bomb problem. You can buy 1,000 of these and build a dangerous device
that would require serious clean-up and, obviously, can hurt a lot of people.

So, this will never be in a smartphone or laptop, but perhaps power industrial
items that can't be practically charged often like remote robots or sensors.
Or applications in space to replace aging, expensive, and heavy RTG's.

~~~
nathan_f77
> You can buy 1,000 of these and build a dangerous device that would require
> serious clean-up and, obviously, can hurt a lot of people.

Or you can buy $1,000 worth of lithium batteries and try to build a breeder
reactor in your back yard:
[https://en.wikipedia.org/wiki/David_Hahn](https://en.wikipedia.org/wiki/David_Hahn)

Oh no, I didn't know he passed away only a few months ago. And that's very sad
to read about the rest of his life.

~~~
drzaiusapelord
The lithuim is just used to purify the thorium he illegally acquired. I don't
think your comparison really works here.

------
etatoby
> _diamond is the hardest substance known to man, there is literally nothing
> we could use that could offer more protection_

Weird, I was under the assumption that density (and other more exoteric
chemical properties) shielded from radioactivity, not hardness. /s

~~~
ryao
Maybe they meant protection of the containment itself.

------
bahjoite
> Obvious applications would be [...] high-altitude drones

This made me wonder about the funding for this research, but then I found that
Dr. T Scott is involved with[0]:

> Radiation Mapping Using Unmanned Aerial Vehicles

> Following the events at the Fukushima Daiichi Nuclear Power Plant, the
> Interface Analysis Centre has been developing an unmanned aerial system
> capable of mapping radiation in regions inaccessible to humans.

[0]:
[http://www.bristol.ac.uk/physics/research/iac/casestudies/](http://www.bristol.ac.uk/physics/research/iac/casestudies/)

------
Symmetry
Normally with nuclear power you use the heat generated to drive a heat engine
of some sort with strict limits on the theoretical efficiency. But many pulse
fusion designs look at using the momentum of emitted charged particles
directly through their interaction with magnetic fields at far higher
efficiency than could be achieved with the energy going through a heat stage.
Carbon-14 emits only beta particles which are, of course, all negatively
charged. I wonder if they've managed to turn those into a very high voltage,
very low current continuous source directly?

------
downandout
IMO the headline here isn't the minimally powered batteries, it's that this is
a potential solution to the (very) secure storage of nuclear waste. In the US,
for example, the proposal to store essentially all of our nuclear waste at one
site (Yucca Mountain in Nevada) is a truly terrible idea that would create the
world's most coveted terrorist target. Encapsulating the waste in small
diamond shells that could be distributed among several sites seems like an
ideal solution if they can get it to work at scale.

~~~
arama471
Why would anyone attack that facility? Its extremely easy to secure - If you
somehow neutralize everyone protecting it you still wont get in and out with
any meaningful amount of material before a military response comes in and
removes your ability to actually do anything.

Note that Yucca Mountain doesn't just have piles of fissile material - all the
waste is in the same concrete capsules they arrived in. The ones that need a
crane to be moved[1][2].

You could argue that these will fail before we know what to do with them and
that they will leak radioactive material over time, but that still wouldn't
make it a good terrorist target.

[1] [https://www.nwmo.ca/en/Canadas-Plan/Canadas-Used-Nuclear-
Fue...](https://www.nwmo.ca/en/Canadas-Plan/Canadas-Used-Nuclear-Fuel/How-Is-
It-Stored-Today)

[2]
[https://en.wikipedia.org/wiki/Dry_cask_storage](https://en.wikipedia.org/wiki/Dry_cask_storage)

NOTE: Sources don't say that you cant move these without cranes, they just say
that these are larger than a person and made of steel and reinforced concrete
so I thought it would be a safe assumption these are a pain to move.

~~~
downandout
So if someone bombed that facility with large conventional weapons, or
detonated a low-yield nuclear device there, the casks wouldn't leak?

~~~
tdb7893
At this point you are talking about blowing up part of a mountain and if
someone can do that you are already in trouble.

------
emeraldd
(Note this math is a thought experiment ... completely off the cuff and utter
non-sense.)

Based on their numbers:

AA is about 700J/g @ 20g gives about 14000J and a 24 hour drain gives us
580J/hour.

DiamondBattery is about 15J/day or ~0.5J/hour

Ignoring voltage issues (among other things), we come to 1.1kg of
DiamondBattery being able to supply something that would drain their 20g AA in
24 hours.

The math here is complete off the cuff non-sense, but an extra kg or so here
is not unreasonable for some fixed applications ...

~~~
drzaiusapelord
This is a little disheartening in terms of robotics. For a non-trivial robot
with a handful of 12V motors and a decent workload, I imagine this would add
tens of lbs compared to only a handful of ounces using lithium. Of course,
those tens of lbs means more power needed to push the robot and you quickly
hit the laws of diminishing returns.

~~~
emeraldd
Of course, we're talking about less than first-gen tech here as well.

------
iseanstevens
The part where they list "airplanes" as something it could potentially power
was where it became silly... that's gonna be a lot of spent fuel rod mass.

------
jules0
Given that Bristol researchers did not explain the physics behind their
diamond battery we can only speculate but considering some recent developments
we can make some good guesses.

It probably functions similar to a betavolatic cell. (See:
[https://en.wikipedia.org/wiki/Betavoltaic_device](https://en.wikipedia.org/wiki/Betavoltaic_device))

In a typical configuration you have a P-N semiconductor junction placed next
to beta emitter. The beta particles impact the PN junction and create
electron-hole pairs that are pulled apart by the junction to produce a
current.

The use of diamond seems like a could be a significant innovation: 1)
Carbon-14 is an efficient beta emitter and could make op part of all of the
diamond material. 2) Diamond has a wide band-gap which is necessary for high
efficiency conversion to electricity. 3) Has strong resistance to radiation
damage.

In one configuration the diamond would be layered on top of a silicon P-N
junction so it works like a conventional betavoltaic device. (see:
[http://large.stanford.edu/courses/2013/ph241/harrison2/](http://large.stanford.edu/courses/2013/ph241/harrison2/))

A recent patent shows that diamond is a very efficient moderator for injecting
electrons into the junction. (see
[https://www.google.com/patents/US9064610](https://www.google.com/patents/US9064610))

Considering that diamond is itself a semiconductor we could also do away with
the silicon. For example diamond is being considered for highly efficient
photovoltaic cells. (see:
[http://exploration.vanderbilt.edu/news/news_diamond.htm](http://exploration.vanderbilt.edu/news/news_diamond.htm))

It is also being considered for production of next-gen schottky diodes. (see:
[http://www10.edacafe.com/nbc/articles/view_article.php?artic...](http://www10.edacafe.com/nbc/articles/view_article.php?articleid=207252&section=ICNews))

The diamond could be stacked next to a conducting metal to create a Skottky
barrier which is a type of P-N junction. The beta particles would excite the
electrons with enough energy to push them over the barrier and create a
current. (see:
[https://en.wikipedia.org/wiki/Schottky_barrier](https://en.wikipedia.org/wiki/Schottky_barrier))

------
rbanffy
Would anyone care to explain how this works? The crystalline structure of the
diamond and the directionality of the radiation source doesn't give me a clear
idea about where to add terminals to this battery.

------
jlebrech
in a diamond battery what serves as anode and cathode, how do you connect
wires to a diamond?

this diamond making process would be quite hazardous.

I wonder if they should just create a layer of diamonds and and sandwich that
between C14 rather than try and rely just or those diamonds to power
spacecraft (would save having to develop the non-radioactive diamond layer).

would a standard diamond also do that trick, I don't see why a radioactive
diamond would be different if it is in the presence of C14?

~~~
rini17
There are diamond LEDs so this is solved problem, I think by adding very
specific impurities.

------
known
Reminds me
[https://en.wikipedia.org/wiki/Toshiba_4S](https://en.wikipedia.org/wiki/Toshiba_4S)

------
transfire
Damn. I was hopeful if used gamma radiation. That would have been truly
revolutionary.

------
brandmeyer
10:1 odds that this is just a use of the photoelectric effect with a clever
dielectric. Based on the press-release description, it is probably not a
radiothermal generator (like that used in deep space probes).

1) Have an ionizing radiation source.

2) Get a robust dielectric, with metal plates on both sides of it. Call the
plate near the radiation source the cathode and the far one the anode.

3) As the ionizing radiation impacts one side of the cell, the released
electron travels only a short distance through the cell. Ideally, the first
interaction is with a cathode and the far side an anode, imparting a negative
potential to it.

4) A potential difference now exists between the far-side anode and the near-
side cathode, from which you can draw current.

Strictly speaking, this is a more like a capacitor which is trickle-charged by
the radiation field rather than a battery. There is a design tradeoff between
thickness of the metal and dielectric layers in that the initial and final
ionizing interaction must be of a (cathode/dielectric -> anode) or (cathode ->
dielectric/anode) to get any energy out of it. Ideally, the dielectric has an
extremely small cross-section for interaction with whatever the ionizing
radiation source is, while the metal plates interact very strongly. However,
there will always be some losses due to internal ionization of the dielectric
itself. I'm not sure how you would build an effective multi-layer structure,
either.

Is this preferable to an RTG? Almost certainly not. The vast majority of the
radiation energy in an ionizing photoelectric-effect cell is still released as
heat. Very little energy can be captured this way, so it is quite inefficient
in terms of energy produced relative to the radiation emitted. You can extract
some more electric work by pre-charging the cell such that the freed electron
is slowed in part by the electric field gradient, but in practice the bulk of
the energy is still lost as heat.

Sea story time! The internal electric field within the dielectric will produce
some weird mechanical stresses, too. When my ship's reactor plant went through
a refueling overhaul one of the things they replaced was the reactor
compartment windows. There are a couple of leaded glass windows that allow Mk.
1 eyeball inspection of the reactor compartment during operation. They are
quite thick, electrically insulating, and they build up a large internal
electric field along with internal stresses. Standard maintenance was to
replace them well before the stress could fracture the glass.

So... could the press release be ...excessively breathless? My guess is a
qualified "probably". The physics behind the photoelectric effect are well
known and understood. Diamond is special in part because it has a
fantastically high dielectric breakdown strength. So, you can extract more
work out of the ionized electrons by supporting a very high potential gradient
between the anode and cathode, which could be seen as a breakthrough for this
type of energy conversion device. BUT it also would enable a new generation of
high-density ultra-capacitors. The energy density in a capacitor is limited
(in part) by the breakdown strength of the dielectric, since the stored energy
is a volume integral of the squared electric field strength. Since ultracaps
are technologically much easier to commercialize, and much more investor-
friendly than anything involving an ionizing radiation source, but that isn't
what the press release points to, I think it is likely to be ... exaggerated.

I could also be wrong, and we'll soon have a new generation of ultracaps!

------
codebook
How much is it? same as diamond?

~~~
imagist
Low-quality diamonds can be manufactured more cheaply than the synthetic
diamonds intended to compete with the jewel industry. I imagine this prove
would come down with the scale batteries are manufactured at.

------
kbradero
mm, I remember from a lecture that 'nuclear waste' is actually a label used by
the nuclear industry but non all of them can be disposed, some by products can
be used as a base atomic weapons.

So all countries with nuclear power plants have to return/control the 'nuclear
waste'.

------
jaza
Dilithium crystals, anyone?

