[One time]

In GB2 Egon mentions that the proton packs power source has a half life of around 5000 years.

Assuming he means the half life in terms of radioactive isotope decay that would mean the power source is Curium-246.

Curium sits right between holmium and carbon-14 in terms of half life, at 4730 years. There are no other isotopes around the 5000 year half life mark, apart from these three.

holmium-153--4570 years
curium-246----4730 years
carbon-14------5730 years

Interestingly, where holmium and carbon-14 isotope decay yields almost no energy, curium decay yields very high energies.

Infact curium is used as fuel in radioisotope thermoelectric generators on board spacecraft:

https://en.wikipedia.org/wiki/Radioisot ... _generator



Also curium decays with α-particle radiation which is a lot safer to humans than isotopes that decay using much more dangerous beta radiation (& gamma/X-rays). That is another reason why curium has practical application uses in spacecraft as opposed to isotopes of e.g. radium, or uranium.

It's crazy how specific Aykroyd's science is when you look for it.

PS: You'll note the pressure venting device in the illustration above.

[NotSabbat]

Neat!

[Fritz]

Also curium decays with α-particle radiation

And alpha particles are two neutrons and...tah-dah, two protons.

Good find.

[JWils23]

So awesome! I remember watching a documentary a few years ago where Aykroyd was talking about Ecto 1 and the other tools of the trade. There wasn’t one item that he didn’t know the purpose and backstory of. I looked up some of the things he said and the science was spot on, made me appreciate the movie even more.

[One time]

So awesome! I remember watching a documentary a few years ago where Aykroyd was talking about Ecto 1 and the other tools of the trade. There wasn’t one item that he didn’t know the purpose and backstory of. I looked up some of the things he said and the science was spot on, made me appreciate the movie even more.

I was pleasantly surprised when I heard that he told the guys at Terminal Reality what to call the different pack modes and also insisted on them calling the ghost trap a "muon" trap.

Muons are known to penetrate through everything (much more than X-rays) and they don't give off much radiation when they decelerate (hit something.) That makes it an ideal choice for a ghost trap entrapment cone that has to:

a.) work in all weather conditions, penetrate through anything in between it and the entity
b.) be "safe" to use in public

In fact muons have a practical application in muon tomography systems:

https://en.wikipedia.org/wiki/Muon_tomography

It's funny how Aykroyd explains part of the equipment on the roof of the Ecto-1 as "muon scrubbers".
at 11:15s into this video:

https://youtu.be/SjXvCHnHjVw?t=672

I guess to decontaminate the GB's and the environment from trace particles of muons after a bust?

PS: Muon decay produces electrons, which could explain the blue sparks coming out of the entrapment cone when the trap is open.

[One time]

I was bored this Sunday morning and decided to try to calculate the power output of a proton pack. Lets see if this exercise is going to work. If there are any engineers feel free to correct this most likely faulty calculation. I'm an architect, not an electrical engineer or a nuclear physicist.

The canon lists the electric output of Ghostbusting equipment as respectively 1 kV for the Trap (movies) and 3 kV for the Proton Pack (GBTVG). Let's look at the wattage and amps.

Curium apparently yields about 4 watt per gram when used as fuel by heat generated through decay in radioisotope thermoelectric generators. Basically it glows red hot because of radiation and constantly generates heat. If we assume the packs have about a 1kg sample, this means 4000 watts of constant power. So a 3 kV proton pack powered by a kilogram of Curium fuelled RTG, so consuming 4000 watts would mean it's only drawing about 1.33 amps.

3kV and 4000 watts is akin to a large electric generator. For example a fridge uses about 1500W, a jacuzzi about 2800W. This kind of power could power smaller cyclotrons such as those used in medical devices, X-Ray machines, radiotherapy machines, etc. But the power -output- of these are around 50-100 watts maximum, like a light bulb. Cyclotrons are very inefficient in converting the power they consume into the power they produce.

Obviously that is too little power for what we see the beams in Ghostbusters do.

Judging from the proton beam destruction of the bar in the Sedgewick Hotel scene I'd guess the power output is around 50 kW. Similar to the destruction a 300lbs man would cause if crashing into that bar running at about 22 mph. A strong firehose is about 30 kW so that sounds about right.

But cyclotrons are very inefficient.

http://accelconf.web.cern.ch/AccelConf/ ... 1_talk.pdf

Depending on the size the efficiency varies from (small cyclotron) less than 1% to (large cyclotron) around 14%. Lets take 3%.

That means we would need to consume 30x the power needed to be able to output 50kW. So we would need 1.5 megawatts of power. 1500000 watts at 3000 volts which would draw 500 amps.

1.5 MW of power can power around 200 homes simultaneously. As a comparison, the worlds largest particle accelerator, the Cern large hadron collider uses about 120 MW of power. That is a serious electricity bill.

Anyhow so we could say the proton pack consumes about 1.5 million watts. That means the 4000 watts generated by using the 1kg of Curium as fuel in a radioisotope thermoelectric generator would be nowhere near enough. That leads me to think that the Curium maybe isn't used as a simple heatsource through decay, but is used as actual nuclear reactor fuel through fission. The fission of 1 g of nuclear fuel (like Curium) per 24h liberates about 1 MW of power. That would mean there is a miniature nuclear reactor in the proton pack.

Edit: lol, this is what Wikipedia says

"All isotopes between 242Cm and 248Cm, as well as 250Cm, undergo a self-sustaining nuclear chain reaction and thus in principle can act as a nuclear fuel in a reactor.

245Cm and 247Cm have a very small critical mass and therefore could be used in portable nuclear weapons, but none have been reported thus far."

Then again parts of the proton pack could be nuclear powered and parts could be RTG powered. Here's a list I found of parts.

Ok my mind is fried, I should never have done this on a Sunday morning.

[One time]

This is a response to:

https://www.gbfans.com/forum/viewtopic. ... 3#p4986203



GbTVG showed a "venting" system as seen in RTG's but I don't believe the packs use a radioisotope thermoelectric generator at all. In any case, not only an RTG.

RTG's are used in reality for space sattelites/probes, etc. because they deliver a constant very low power for decades.

Looking at isotope half life and picking one closest to 5000 years for Ghostbusters won't work (I think).

If we assume Ray's: "16 ounces of fuel isotope (450 grams)" line in Afterlife, is the fuel required per proton pack, then:

Carbon-14 (through decay) yields only 0.0002 watts per gram (15 joules per day), so 450 gr would yield 0.09 watts. Although this is less than a single AA battery it will yield this power for ~5700 years. But it's very low power. This isotope is used in things like betavoltaic batteries in pacemakers.

In real spacecraft, isotopes like Plutonium-238 are more common as these generate 0.5 watts per gram, for ~87 years. So for 450gr we get 225 watts. Still lowish power, about enough to run a single desktop PC (for 87 years, until it halves). The main point of a radioisotope thermoelectric generator is that it delivers low power for a LONG time.

IMO proton packs would instead use the isotope as nuclear fuel in a nuclear fission reactor as opposed to an RTG.

In this case Curium is interesting because not only does it have a 5000 year half life but according to wikipedia: "Curium is not currently used as nuclear fuel due to its low availability and high price.[44] 245Cm and 247Cm have very small critical mass and so could be used in tactical nuclear weapons, but none are known to have been made."

That 5000 year half life line may have been very specific by Aykroyd.

Then again, I have never seen any reference to proton packs having an inbuilt nuclear fission reactor. (very different than a particle accelerator/cyclotron).

But interestingly nuclear fission reactors feature venting systems to prevent the coolant overheating.

I'm pretty sure that to make a proton pack work in universe you'd need a small nuclear fission reactor built into them. Where else are you going to get the power from? Batteries? What battery gives the required (megawatt) power output for 5000 years straight? Definitely not an RTG.

I'm almost 100% sure they have a nuclear reactor inside. The reactor is probably somewhere above the cyclotron disk. Maybe it's the PPD? The PPD stands for Primary Power Distributor afterall. Maybe I'm not the first to think of this? Maybe the Booster is the "cooling tower" of this reactor? It looks like one.

Thinking about it, the silvery cylinder with the "DANGER" sticker next to the PPD looks to be a metal object about 450gr (16 ounces). Perhaps the (radioactive) fuel isotope is in that, and that's why it has a danger sticker? In the central dimensions of the overall pack it also lies the furthest from the body of the wearer. Who knows?



PS: you may also find this interesting:

https://www.gbfans.com/forum/viewtopic.php?t=44617