I have a PhD in nuclear engineering my career is in R&D, including a new radiation detector designed to be low cost and better than a Geiger counter. Ask me anything about that project, radiation detection general, related topics like nuclear ...

What limitations does the current Geiger counter have and how does your detector address those issues?

I tried to give a more thorough answer to that question on Kickstarter page and my web site, but the short answer is that the main problem with existing Geiger counters is that they are very limited in sensitivity. That is simply the nature of Geiger tubes (the main component inside a Geiger counter). Geiger tubes are gas-filled so most radiation passes through without interacting. A solid sensitive element, like in my detector, stops much more radiation that hits it, making it more sensitive. If a detector is more sensitive, it can identify weaker and/or farther away sources of radiation, or to put it another way - smaller variations in radiation fields. A source has to be pretty strong for a Geiger counter to clearly identify that it is something significantly above the ordinary background level. A more sensitive detector can detect smaller variations and/or can detect the same variation faster.

That's the most important difference. Perhaps second is accuracy, all interactions in a Geiger tube result in the same signal. In a scintillator detector (like the Better Geiger) each interaction produces a different signal size, and that allows the energy of the particle to be taken into account. To make a long story short that imrproves accuracy when calculating not just "interactions per second" but "radiation dose" (i.e., health risk to humans). I consider this secondary to sensitivity because sometimes it's not essential to have a highly accurate reading, sometimes a coarse reading is enough, but having more accuracy is always a good thing.

Third is ruggedness. Geiger tubes can break because they have a fragile wire inside. Detectors with scintillators inside have the possibility to withstand much more mechanical shock if designed correctly.

Last is not really a fundamental "limitation" of Geiger counters, but I think my product was designed in a much more user-friendly way than existing options, but that's subjective and up for the users to decide if they agree with me or not.

I use a Geiger counter in my work (we use p32, a beta emitter) and the counter does the job very well. Would your detector be able to pick up alpha particles? What is the expected cost relative to current counters?

Finally, for whom would this new counter be useful? In my work, it's not really important to have the detector tell us the kind of radiation because we already know what kind it is. What use cases are there for needing to instantly ID the type of radiation?

The issue of alpha detection is described in detail on the kickstarter page and www.bettergeiger.com , but to give a short answer - if you want to measure alpha contamination in the air, you need a device which is designed specifically for that one purpose, and those devices already exist on the market at reasonable prices and pretty decent performance (although they are very slow, they need many days of measurement to get an accurate reading). For "local" strong contamination of an alpha-emitter, like on a surface, generally beta and/or gamma emission will also be present, so such a contamination can also be located without the detection of alpha particles. My device and most Geiger counters are therefore not designed to be sensitive to alpha particles. It would have added a lot of cost and complexity. It is not that they are fundamentally not sensitive to alpha, but that alpha particles only penetrate an extremely thin layer of solid material, so you need a measurement window which is very thin and fragile, this is contrary to the other goal of making the device robust. The plastic enclosure of my device already stops all the alpha particles, in other words.

For your use case where you know that you are dealing with a beta emitter, and you also don't want to use the detector for other purposes, then the Geiger counter you use is probably perfectly fine. Most people would want a more general-purpose tool.

The cost is as described on the Kickstarter page, and in the long term I expect it will stay roughly around this $99 price point.

To clarify - my detector does not instantly ID the type of radiation, this is a very specialized task that is rarely required, but what it does do is calculate the radiation dose in a way that factors in the energy of the incoming particle. For example, if 100 particles of 100 keV are detected, it is a lower radiation dose than 100 particles of 1000 keV, and the detector is designed to compensate for that (this is impossible with a traditional Geiger tube, because of the physics of how they work).

I will copy here from another question about your other point:

There are many reasons a person might want a radiation detector, aside from using it in a professional environment. My favorite reason is education. A person can learn about radiation, the technology associated with it, and they can try to find sources of radiation in their daily lives. Or, if you add on the test material option on my Kickstarter, you'll have a source of your own to play with. I plan to write out a guide on some educational experiments to do with that. Another reason many people want a radiation detector is preparedness. If there is some kind of nuclear incident, they would have that tool in their toolbox to monitor their surroundings. Even in professional or quasi-professional environments (like volunteer first responders) people might not have access to all the equipment they need. I've heard this being the case even in hospitals, where they have badge-style dosimeters but often do not have easy access to "real" detectors like mine which gives live information - and for that type of situation people might want to supplement the situation with their personal equipment.

I used a CoMo 170 which uses the scintillation method with a photomultiplier and no gas chamber. I know that that device can't detect very small amounts of activity like a germanium detector for whole body counting. How does your device differentiate from the CoMo and how sensitive will it be when comparing it to a germanium detector?

That looks like a cool device. It's specifically designed for surface contamination. It is very capable and surely very expensive (somewhere between 10x and 100x more expensive than mine if I had to guess). It will also handle alpha detection (unlike mine). I think it could detect pretty small amounts of radioactivity. My device is pretty sensitive but it looks like not as sensitive as that one. The important difference is cost, it's aimed at a different market. Compared to a germanium detector (HPGe) that CoMo and my device are much more sensitive, but that's not the point of HPGe, the point of HPGe is to get a very finely resolved energy spectrum. Neither mine nor the CoMo has that capability. Although, my device give an energy-corrected dose, whereas the CoMo only gives reasonable dose information if you add a separate Geiger tube inside as an add-on (according to the spec sheet).

But does it still make the clicking sound?

Absolutely. If not, what's the point?

Do you think we'll ever get past the general stigma against nuclear energy?

You can't bring it up in New Zealand for example, without someone crying "that's illegal"

Sadly, no, I think there will always be a stigma. Nuclear energy is a big complicated thing with some risks if not handled properly, and a part of the population will always be skeptical of that, even if there is a scientific consensus about the current generation of reactors being extremely safe and an essential tool in fighting climate change. On a more optimistic note, though, I do think there is room for it to gain in popularity, as the effects of climate change become more and more dramatic in our daily lives, so even if there is opposition maybe there enough support will grow over time to really increase construction of new nuclear power plants. Time will tell.

We have a local company who won't use their electric boiler because it costs 400k a month to run, all the while, coal is dirt cheap. That same company wants to implement hydrogen powered trucks, but again the cost of electricity hampers its effectiveness.

I've still got a few years til I'm done with my degree, there's time for options to shift.

I believe it's possible. But it'll be the product of a life's work and climate deadlines being closer than they appear.

It's silly to use dirty fossil fuels to produce hydrogen to fuel a car.

Rick Sanchez voice: That's just global warming with extra steps.

Also, electric cars are fine but the benefit is greatly reduced as long as they are powered by electricity produced from fossil fuels. Clean electricity plus electric transportation is the way to go, and even then you'd better have more buses and trains if you really want to make a big difference.

I’ve never gotten a good answer on this, maybe you could shed some light.

I was a reactor operator in the Navy for ~6 years. We measured exposure in Roentgen Equivalent Man (REM) while it seems that the rest of the industry uses Sieverts as the standard unit.

Do you suppose this is just The Navy’s unwillingness to change, or perhaps there’s a good reason for it?

Thanks in advance my friend.

As you know, but some others might not, Sievert and Rem are interchangeable except for a factor of 100. The "rest of the industry" in the US also uses rem for the most part, including civilian nuclear power, so it's not just the Navy.

I don't know if I'd call it "unwillingness to change" exactly, but rather there is enormous institutional inertia. To switch units would require a lot of people changing their vocabulary, updating a lot of documents, etc. If there were a real benefit to doing it, maybe it would be worth it, but as it stands it just doesn't really matter, either unit can be used to get the job done and they are easily converted from one to the other if necessary.

As to why exactly the US and the rest of the world went in different directions on that particular unit... I'm afraid I don't know the answer to that, but would be curious to learn it if someone else does.

The big one of course: do you think Thorium will be successfull?

I can only answer that question with another question... why does it need to be successful?

Modern light water reactor technology is extremely advanced and safe, and we have an enormous amount of experience and history with it. We have lots of uranium. There is no urgency to switch to thorium. Not only that, even if thorium didn't exist we could use uranium almost indefinitely.

Switching over to thorium means using much newer, less established, less well-proven technology. It might make sense in the longer term due to some potential advantages, but in the short/medium term I think it makes more sense to dramatically scale up proven technology to fight climate change.

Do you think people might be less scared of Thorium? Since nuclear has a very bad stigma attached to it, Thorium might have another chance?

I think this is a very good point to consider. It deviates from the technical question, though, and drifts into psychology and how nuclear energy is marketing. I am not very optimistic that this superficial marketing advantage of avoiding the term "uranium" will somehow convince people. I think if the technical merits cannot be conveyed and accepted, whether uranium or thorium, then the basic story will not change regardless. Some people will still hear "nuclear" and think "nuclear bad!", whether or not that is an informed opinion.

You don't think development of molten salt reactors is worth the effort.

I do think it's worth the effort. I just think it is not urgently needed to solve an imminent problem. I am also realistic about the fact that getting MSRs into the world in any significant quantity will take a minimum of a few decades, whereas standard LWRs can be scaled up much sooner (if there was the willpower to do so).

Lets get to the root of a lot of people's questions here: did you watch the HBO miniseries on Chernobyl and what are your thoughts on it?

I have not built up the nerve to watch it yet because I know it is full of inaccuracies and will just make me really angry. I don't think it would be good for my mental health.

I don't mind inaccuracies in an ordinary work of fiction, but it kind of paints itself as accurately representing events to some extent, which it most certainly did not. This makes it shapeshift from a work of fiction into a genuine source of misinformation.

Even if it does make you angry, the very fact that it's a popular source of misinformation makes me think it should be important for you to watch. You're going to run into a lot of people with bias derived from this series and if you want to be able to respond to it in a productive way the best way is to know both the accurate information and the source of misinformation.

Good points.

Hi, another nuclear engineer here. You mentioned you're using a scintillator, but that it's also "rugged." But scintillating material typically comes in crystal form that is somewhat fragile to mechanical shock. Specifically, I'm thinking of low cost scintillators like NaI(Tl), which crack readily, ruining your resolution.

While this might not actually be a problem because it doesn't seem like you're using this for spectroscopy, but instead like a geiger counter, can you speak to why you chose a scintillator and not a semiconductor like CZT, which is already used in similar small size applications, is far more rugged, and you don't have to deal with light and water tight sealing around the scintillator crystals and photomultipliers?

The main thing is that scintillator is protected by being cast into epoxy. When the epoxy hardens, it offers a lot of protection.

CZT is fairly expensive and also more demanding in terms of the electronics needed to process the signal. Sealing a scintillator from humidity and light is not difficult (the epoxy is for that purpose also).

Along these same lines, what sort of durability testing have you done? Any sort of drop tests, shock, vibe, anything like that?

Drop test isn't good even with a Geiger.

This is claimed to be a Better Geiger, using a solid state sensor, so I guess I'm just wondering how far that goes

I dropped my Atom Fast 8850, gamma ray scintillation detector a few times and it works fine. It's quite robust. It year and a half old, I've had no problems. I did read about somone getting low readings and ppl suggested his crystal had cracked, but I might have been like that when it arrived, it was still under guarantee.

The Radex Obsidian and Radiacode-101 are gamma ray scintillation detectors and spectrometers, they are quite durable. I haven't seen people complaining about being fragile.

It might have cracked, or the scintillator might have not been properly coupled (pressed against) the photosensor.

There's already several cheap Russian gamma ray scintillation detectors on the market.

Atom Fast 8850, Radex Obsidian and Radiacode-101

They are very robust. I dropped my Atom Fast a couple of times and it still works. Also, it uses very little power, the battery lasts a month. It connects to my phone over Bluetooth LE, I map radiation using an app, Atom Dosemeter.

Here's a radiation map I made using the Atom Fast.

They are very popular in Russia and eastern European countries but are hardly known in the west. The makers of the Atom Fast run a website where users can publish their maps, hardly any uploads are form owners in the West.

The Radex Obsidian and Radiacode-101 also do basic gamma spectroscopy.

Came to see this. Doesn't seem like it revolutionize anything. It's just a scintillator.

I never claimed to revolutionize anything. The next cheapest scintillator detector is roughly 3x the cost of mine. It's intended to fill a gap in the market, not to make all other options obsolete.

Why would you need a kickstarter? And why would any individual need a radiation monitor - anyone who works around radiation would already have access to the equipment, and anyone who doesn't would never have use for it?

As an individual trying to get this product off the ground, scaling up production is a lot of up-front investment. I don't have deep pockets to simply roll the dice with that kind of money. I already sacrificed a normal income for much of this year to spend my days developing a prototype (along with some actual costs associated with that). A Kickstarter lets me essentially get an advance on the first set of orders. It is a bridge from a prototype to a having a product being sold in a normal way on the market.

There are many reasons a person might want a radiation detector, aside from using it in a professional environment. My favorite reason is education. A person can learn about radiation, the technology associated with it, and they can try to find sources of radiation in their daily lives. Or, if you add on the test material option on my Kickstarter, you'll have a source of your own to play with. I plan to write out a guide on some educational experiments to do with that. Another reason many people want a radiation detector is preparedness. If there is some kind of nuclear incident, they would have that tool in their toolbox to monitor their surroundings. Even in professional or quasi-professional environments (like volunteer first responders) people might not have access to all the equipment they need. I've heard this being the case even in hospitals, where they have badge-style dosimeters but often do not have easy access to "real" detectors like mine which gives live information - and for that type of situation people might want to supplement the situation with their personal equipment.

Not disagreeing with you at all on any of these points but there are reasons most hospitals and emergency response teams dont have very robust detectors.

Biggest being is that its too much knowledge required in a specialized field for say a firefighter or hospital security guard to have. The institutions they work for have a whole radiation safety department who advise and support them in emergency situations. Accurate and specialized detectors are often held by Rad. Safety teams for when they need to identify or quantify contamination. For example the Fluke Ray-Safe 452 is a new fantastic new detector that is a combination of solid state and GM. It even handles pulsed radiation well.

Id rather response teams just know when their Personal Radiation Detector vibrates there is an unsafe amount of radiation nearby and they report it back to their superior.

Hell, nuclear medicine techs barely understand how detectors work, all they know is they survey and when it beeps a lot there is contamination. They then tell their superior and they deal with it.

Itd be far to expensive and impractical to train and educate all these individuals in radiation/health physics and engineering on top of their existing expertise.

I really appreciate your efforts in bringing advancement and innovation to this stuborn field and hope you can find financial support to give Ludlum and Fluke a run for their money.

My experience lines up exactly with everything you wrote here. In its existing form the detector I'm offering has limited applicability in a professional environment. I could imagine developing another version which is more thoroughly characterized and calibrated according to the needs of a professional radiation worker, but there are a lot of barriers to entry and I was not ready to do that as a first step. Maybe in the future.

That's kind of a good point, I myself had just completely glanced over the Kickstarter part without a second thought. Presumably if this works as well as he's implying that it does, and has the advantages over existing instruments that he says it does, then existing companies would be providing funding, as opposed to random people.

OP, is there some caveat to this that makes it unappealing to the existing groups that already have a lot of experience in the market?

Is it not obvious that it is more attractive to me to remain self-funded (with the help of a Kickstarter campaign) rather to try to borrow money or partner with a company? Companies don't just "provide funding", they give money in exchange for something. I would be losing some degree of creative control and autonomy over the product, not to mention financial considerations.

As an aspiring student in related fields, how difficult was it to get to the point where you are at? What would you recommend to someone who would want to follow in your footsteps?

To answer your first question, difficult is a relative thing. Studying engineering takes a combination of hard work and an ability to handle complicated topics including math. A person can get through with some combination of the two, like a lot of work and a little natural ability, or a lot of natural ability and a bit less hard work - but at the end of the day some combination of the two is necessary. Usually more hard work than natural ability. So anyone who wants to study engineering or some other technical discipline should be prepared for that. Maybe inside the scope of "hard work" there is something more complicated - an element of discipline, time management, and task prioritization that must be mastered. I think that's something I personally did well, but others struggled with - even if they had more raw intelligence than me. Maybe being conscious of that skillset is important, be careful about how you spend your time when you're studying or doing projects. It might make the whole thing slightly less "difficult".

On the topic of your second question, I was always interested in technical things and I liked math, so studying engineering was a clear choice for me. I know others struggle much more with choosing what career path to go down. At the age you are forced to choose a major (if you go to college) almost nobody is well equipped to make a perfect decision on what career they want. On the other hand, I think what is not well communicated to people is that what you major in does not send you on an extremely strict path in life. An engineering degree does not lock you into one narrow day to day life experience. Depending on your engineering discipline you will generally have a wide range of options to specialize in, whether it be hands-on laboratory work or programming at a computer all day. If you decide you don't care as much for the nitty gritty technical stuff you can drift into more people-oriented roles, like sales. Some people go on to get an MBA for a more high-level managerial role. Some people look back on their engineering degrees as blips in their career. My point is, committing to an engineering degree does not necessarily mean you transition to a variety of career roles. It does mean a challenging and math-heavy education, so a person needs to be prepared for that if they study engineering. After that it can go in a lot of directions. This was a long rambling way of answering your first question in that someone should probably not try to "follow my footsteps" but just take their education and career one step at at time and work step by step to build an interesting and fulfilling career.

At what age did you start your education into that field?

I started with a bachelor's degree in nuclear engineering. That was basically an accident - I originally planned to study mechanical engineering but there were significant financial incentives for me to study nuclear instead, so I thought I'd give it a try. I ended up liking it, one thing lead to another, and here I am.

Is 3.6 roentgen really 'not great, not terrible' and the same as a chest x-ray?

I had to look up that reference, haha, good stuff - I found a supercut - https://www.youtube.com/watch?v=ocBVLMHK6c8&ab_channel=N0ught0

In the show they call it "Roentgen per hour", that's not really a unit these days, so I'll just say it's roughly equivalent to the modern unit of "Roentgen equivalent man per hour" or "rem/hr".

Roughly 400 rem is the LD50/30 acute dose, meaning the dose over a short period of time you have a 50% chance of dying in 30 days. Therefore at 3.6/hr you're pretty far from that if you are exposed for a short time (you need 4.6 days to reach 400 rem). At the risk of spiraling into a lot of other topics, though, generally ALARA is advised - as low as reasonably achievable. So, you should not needlessly expose yourself to radiation. At low amounts, though, the risk is essentially negligible.

Radiation safety can be boiled down to three things: time, distance, shielding. If the dose rate is high, you should spend a short amount of time there, move further away (radiation rates from a point source drops off roughly with the inverse of the distance squared, i.e. if you go 2x away your dose might be 4x lower, 3x further away 9x lower, 10x away 100x lower, etc), or add shielding between you and the source. Usually time and distance are easier to implement. Long story short: if there is a strong radiation source, move away quickly.

And yes, very roughly speaking it would be comparable to a chest X-ray, if you were exposed to 3.6 rem per hour for one hour.

Nuclear waste… storing it for hundreds of years screams BIG problem in the future? Or I am just uneducated?

I'd call it a small problem. An enormous amount of energy is generated by nuclear power and relative to that a tiny amount of waste. It is nothing compared to things like ordinary waste, chemical waste, and all the stuff pumped into the air by things like burning coal and gas. The quantities of nuclear waste are so small that it's easy to put a lot of effort into monitoring and securely storing it. Not only that, it can be put back into the fuel cycle eventually to both extract more energy and reduce the amount of waste. Aside from that, there are very well developed deep storage options. I simply see it as a trivial problem in the grand scheme of things.

Do you think we should go ahead with the Yucca Mountain plan?

The Yucca mountain project suffered from an incredible amount of political and legal nonsense, including the NIMBY phenomenon, that had nothing to do with its technical viability. On the one hand I think it would have been a perfectly good storage solution to US nuclear waste, but on the other hand I don't think there is any need to put that material underground right now. In the long term the nuclear fuel cycle can be closed, i.e. nuclear waste can be recycled and used as fuel again and again. If I had a magic wand, I would keep the project running but I would only store waste in a way that it can be retrieved, at least for the foreseeable future.

I did my masters thesis on the ability to measure internally digested radionuclides using normal TLD badges modeled in mcnp and ran a university undergrad nuke lab and lectured. I left the field 12 years ago to become a radiologist because of a lot of reasons but some are was the glacial pace of upgrading our reactors to gen IV or even improved gen III Reactors, lack of reprocessing of our stockpile of reactor fuel and overall political, financial and cultural stalemate on nuclear.

What gives you hope for the future of nuclear energy now? Is anything actually more promising than 1 or 2 decades ago?

Also, what is your scintillating material made from and what is the detector volume and efficiency?

All of what you described are some of the reasons why I shifted my focus early in my career from nuclear energy in the general sense to radiation detection specifically. It is a more dynamic field, I think, because there are new and interesting developments coming onto the market all the time, and also a lot of interesting things going on all the time in the research domain. I still appreciate and believe in the research related more to reactor design and such, but I find it just personally less fun to deal with on a daily basis, compared to something like radiation detectors which are small and I can hold in my hand and play with. That is all not to say there are not new and exciting things happening in reactor design, they are just dramatically slower in making their way into real practice.

What is actually more promising than 1 or 2 decades ago? On a fundamental level I don't think there was any real game changer, but new designs are always evolving and improving, and as of now there is a lot of interest in things like SMRs. It's hard to say if it will fizzle out or not, but the financial side of SMRs has a lot to offer, I think, if nothing else for the fact that each unit is a less daunting investment. One of the main things holding large, traditional-style light water reactors back is the enormous up-front commitment (roughly 10+ billion) to get a payout roughly a decade in the future. With more, smaller, cheaper reactors maybe the barrier to entry will be lower.

Sorry that I can't answer your final question, for now those details are not public because a big chunk of work went into optimizing that aspect. Maybe if I get things moving and the product is fully on the market I will share that. I dream of making this first version open source eventually after I move on to an upgraded version with more features.

Do you see your radiation detector replacing or adding to the existing detector market?

For now adding. I think a substantial portion of people who until now would by a normal Geiger counter would be better served buying my detector. On the other hand, as of today there are some features in existing Geiger counter options that my first product does not have, specifically data logging onto an SD card or via WiFi or something like that. I think a small percentage of buyers actually care about that, but if that's an essential feature then they should buy one of those other detectors - or both, because mine still is valuable to have for its higher sensitivity, among other things. On the other hand, I hope to add those features in the future, so at that point I will not see any purpose for someone to buy an ordinary Geiger counter, except for specialized professional users who need a special kind of Geiger counter for some niche applications. On the other hand, if my product becomes popular than perhaps others will develop some products using the same basic technology as mine, so maybe they will be as good, maybe not - time will tell.

Could you look into adding some kind of connection that will let a computer or arduino-type microcontroller read the current value? Even having holes/pads on the board to that could be soldered with the necessary connection would help.

Then wifi and SD could easily be added aftermarket.

If I had added just exactly one more feature this would probably have been the one. It is hard to draw the line with feature creep, there is always another and another thing you can add.

If this project is successful the larger vision is to have a version 2.0 which has bluetooth capability. This would allow for a wide range of capabilities like you describe.

For now, though, I think this is a minority of potential buyers that want this kind of thing, so I decided to first do the streamlined user-friendly version, and save the features for advanced users for later.

I wasn't suggesting you actually add the wifi or bluetooth or SDHD.

It might be possible to simply add a trace to holes or a pad which someone can use to read what's needed and add it themselves. Having unused components are actually quite common. But only if your circuit has something that can be read/interpreted.

I understand if the board is already designed though.

Yes I understand what you mean. Routing it outside the enclosure still adds that extra little bit of complexity. What I mentioned about a future V2 was meant to be a separate point. I got a few comments about accessing the raw signal and I am going to look it over and see if I can make it somewhat accessible, even if it is a "use at your own risk" feature which requires some soldering.

So... why aren't you farming out funding of this to the US military, Bettis Labs, Argonne Labs, or other government agency that would like a small, reliable radiation detector? If it works as advertised, and you have the IP for it, I'm positive they would fund the crap out of that (and probably miniaturize it to a more mil-spec size/integrate it into another detection unit a la PIP-Boy or a smart helmet). And they would pay you handsomely. Just sayin'... it looks like it works great. Integrating that into a combat helmet so dangerous radiation could be picked up would be an awesome 21st century battle modification in our coming years.

The stuff used in professional markets, and government/defense in particular, has different requirements than the consumer market. For a particular application they might have a long list of specifications that have to be satisfied, with extensive documentation/certification and all sorts of tricky stuff to navigate. That market tends to be dominated by larger players who have experience and resources to navigate that world, me personally as a little guy can't easily just dive into that. Maybe that could be a future step for me. For now, all of those extra requirements beyond what the consumer market requires would ultimately add a lot what I would have to charge for the device, in other words I could no longer sell it for around $99. Those professional devices tend to run in the kilo-buck range.

Are you using NaI or some kind of polymer? What do you do use for the PM tube?

There is no PMT, it is a solid-state photosensor. Regarding which exact one, and which scintillator, I'm unfortunately not sharing that right now because optimizing that was a big part of my R&D effort. As I mentioned in another comment - Maybe if I get things moving and the product is fully on the market I will share those details. I dream of making this first version open source eventually after I move on to an upgraded version with more features.

What is your favorite kind of pasta?

That's a tough question. I'm glad you said pasta, because among the big competitors in the carb scene (pasta, potato, rice) I consider pasta to be far and away the champion. I can't say definitively that tortellini is my favorite but I will just say that it is underrated. If you have - for example - cheese-stuffed tortellini, you have pretty much a 100% chance of cheese in every bite. It's nice to have that one certainty in this uncertain world.

Disappointed that you didn’t say nuclear pasta

Dang it.

Is it true that just a small layer of water will protect humans from all radiation?? I’ve heard you could swim in a nuclear reactor pool and be okay?

Someone else beat me to it, but I was going to link that xkcd as well: https://what-if.xkcd.com/29/

The thing about gamma radiation is that it is a matter of chance whether a given thickness of material stops each gamma photon. As the thickness increases, you stop more and more, but there is always a chance, even a very tiny one, that a given photon can pass through, so you never really stop "all" radiation, even if for practical purposes you can consider it all to be stopped.

Did you have to implement a photodetector when you made the move from ionization chamber to semiconductor? Without the anode wire I assume you need to read out the scintillator light another way. I also assume that there isn't a PMT stuffed in that little system. Are you using solid state detectors?

A Geiger tube happens to be a chamber in which ionization takes place, but to be precisely aligned with accepted nomenclature it is not an ionization chamber, that's another category of radiation detector.

Indeed, as you suspect there is a solid-state photodetector inside.

Would your device be a good way for homeowners to detect Radon in their basements?

Unfortunately not. On www.bettergeiger.com and on the Kickstarter campaign that is discussed in more detail, I also responded to another question about that which you can read. If you have further questions about that let me know.

Will your new detector also tick ominously?

Yes. Check out the video on the kickstarter. :)

Thorium reactors, what’s your stance and why?

I've given a couple responses already about thorium, please take a look and see if they adequately respond to your question. Very short version: thorium might be fine, but it doesn't offer much in the short to medium term that isn't adequately met by ordinary uranium light water reactor technology, in my opinion, and it does require more development effort before it achieves the level of experience and trust we have in normal uranium light water reactors.

Hi! Your thoughts on nuclear fusion energy? Haven't heard much about it lately, but a physics professor of mine used to have a very pessimistic outlook for the near (approx 20 years) future.

I think fusion energy would be a great thing to have. I think we should invest more money in developing it. On the other hand, we have at our fingertips excellent low-carbon electricity production options in the form of fission energy ("normal" nuclear power plants), which we do not take full advantage of. That could be scaled up massively in the short to medium term to really put a dent in global emissions. It does not require any hypothetical or uncertain fusion development. Fusion in the very best case will be really economically scalable in, I don't know, a few decades in the very best case. Probably much longer. Partially that depends on how aggressively we invest in developing it. In any case, we need solutions now, and that doesn't mean fusion - it means plain old fission nuclear power.

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The fundamental problem is economy of scale. Let's say you have a design for a reactor at three sizes - 10, 300, and 1000 MWe, and you need a emergency core cooling pump for each one. For the 300 MWe design you probably need a bigger pump than for the 10 MWe one, maybe even a 30x stronger one, but it's not going to cost 30x as much. You'll have some savings there on a per MWe basis. For the 1000 MWe maybe you need more pumping power, but one pump would be too big so you need to buy three pumps like you have for the 300 MW design. At that point the cost savings at 1000 MW doesn't really help you, you might has well have made three 300 MW reactors. That's just one imaginary pump, though, every part of the system will have different cost considerations, and with a larger reactor different safety approaches might make sense. It's all extremely complicated, the tendency is for larger reactors to be more economical on a per MW basis. On the other hand, at some point the power plant is so expensive that nobody can afford to build it. Perhaps 300 MW is a number that people think is pretty good in terms of economy of scale, but still feasible in terms of being a large scale investment. That's just one consideration, there are many, many others - both economical and technical/safety ones. I don't think there is any simple answer, different companies are pursing different designs based on their knowledge and the incentives on the table (such as government support for specific types of reactors).

In the 10-50 MWe range I don't think it's really a game changer in terms of being a distributed network of generation, that's still a lot of power, and there are plenty of power plants of that size (hydro, for example)... and anyway they would probably be clustered on sites with multiple units, so from that standpoint I don't think there is any technological problem with SMRs. That's very different than, for example, having a solar panel on every house, where things can become more complicated in terms of load balancing and so forth.

The traditional Geiger counter often requires calibration to account for the wearing out of the gas tube, does your scintillating crystal and photomultiplier also require calibration over its lifetime?

Good question. There should be essentially zero long term term drift in performance even with exposure to pretty high radiation fields. The only exceptions would be a lot of exposure to extremely strong radiation fields. If someone has access to such a strong radiation field they hopefully already know that at the extremes every material can be degraded.

What is your favorite cookie recipe?

It may sound trivial, but I don't feel we should trust people to research nuclear devices if they don't have a favorite cookie. Consider it a personality profile sort of test.

Finally a hard question. Almost as hard as the pasta question. If you ask me tomorrow I might give a different answer, but at this moment I can't seem to think about anything except peanut butter cookies. Whether it's peanut butter or anything else, though, there had better be some milk there too.

Do you see us going back to nuclear power ever?

Gradually, I think so, yes. Slower than I would want.

Does the simulation ever end or does it go on forever?

I'll never tell.

Is nuclear power in and around major cities…

Really better than solar / wind turbine for a greener world?

We need to utilize every single tool in the toolbox if we are going to have any chance at fighting climate change. Solar and wind are emerging as excellent and economical sources of energy BUT there is an enormous caveat there. That economical point is based on the existing mix of energy production. If renewables become a larger portion (assuming you don't include nuclear as renewable, which I personally do since it's practically infinite) - then the fluctuations of renewable energy become more problematic, because the other forms of energy production (including the nasty fossil fuels) are by definition no longer around to help mitigate the fluctuations in production of solar/wind. Imagine a world with 100% solar/wind, sounds nice if you don't think about it too much... but how do you handle the fluctuations!? That would require enormous means of power storage. That causes costs to skyrocket, unlike now where solar/wind can pretty much be added into the mix without much consideration of energy storage costs. All of this suggests that the ideal mix would be nuclear for baseload combined with renewables. Whether it's produced near a city or not, nuclear can and should be implemented with great care and safety.

...by the way, all of the above did not mention hydro. Hydro is great as well, but it is very limited in how much it can be scaled up, for the most part there isn't room for much growth of hydro power so I just take it as a given that it is a valuable part of the mix but will not be significantly increased in the future.

Aside from sensitivity, what would be an obvious improvement of a solid state detector compared to a mica-based pancake-shaped Geiger tube? These can detect alpha and beta better than conventional tube geigers, so they kinda fill that niche for now. Am a radiation PhD myself, and am using a detector with exactly that kind of Geiger tube

Those pancake detectors can be quite good for alpha/beta, but still not very good for gamma. They are also fairly expensive compared to mine. Cost is really one of the main differentiators of this device. Also, those pancake devices do not have any energy resolution, it just counts, so correcting dose for gamma energy is not possible.

How realistic is Homer Simpson's portrayal of a Nuclear Safety Inspector?

Pretty close to zero realism. NRC inspectors in my limited experience are pretty hard working, knowledgeable people who take their jobs seriously and are good at it.

As a university student studying NE, what kind of work did you do immediately out of college and how does it compare to the work you studied?

The first thing I did after my bachelor's was an internship related to oilfield explosives. It was very fun but not something that attracted me long-term, the business was about making money and essentially nothing else. Many nuclear engineers are drawn to their work because they believe in the technology and that it can be a positive thing for the world, in terms of reducing greenhouse gas emissions. After that internship I went in the direction of Gen-4 reactors for a bit for that kind of reason, it seemed like an exciting new technology that the world could benefit from. Although that's kind of true I think, that work was a bit disheartening because it seemed very loosely connected with application, i.e. the research trickles extremely slowly towards implementation, perhaps on the scale of decades for Gen-4 reactors. I eventually was drawn to smaller-scale projects, like radiation detectors, because I could hold them in my hand, the innovation was more dynamic, and it was (for me personally) generally more fun.

Why aren't nuclear reactors built deep underground in case of a meltdown?

Far, far, far too expensive.