Ionising Particles Quickly: What's the Best Way?

[God Plays Dice]

I need to ionise lots of particles quickly. Upwards of 1kg /sec. What's the best way of doing this? I'd consider pre ionised solutions boiling etc.

Thanks

 

[mfb]

That needs megawatts of power...
Where do you want that ionization rate, for how long, and why?

 

[jambaugh]

What is the material you wish to ionize? (is it a metal? a gas? light element? heavy?) Do you care about temperature? Do you need to ionize and accelerate the ions or just generate a plasma? Or do you rather want to ionize it at room temp?

In short what is your application?

Doing the math you're talking 10 to 100 thousand amps of current to ionize 1kg/sec. You are also talking about ionization energy per sec of 100s of kilowatts to 1.3 megawatts depending on the element and assuming 100% efficiency. Multiply by at least 10 for even the most optimistic achievable efficiency levels.

 

[God Plays Dice]

Thanks. I want a beefed up ion thruster. I don't understand why they're so low powered. Can't you just increase the mass flow rate and design it a bit more like a particle accelerator to increase the momentum generated?

 

[God Plays Dice]

So basically I want 1 kg per sec coming through any way possible for a long period of time to launch vehicles into space

 

[jambaugh]

...Can't you just increase the mass flow rate and ...

The devil is in the word "just"... it is a major bit of engineering. Again you must appreciate the currents you must produce... and at the ionization voltage of the material this will be a lot of watts.

Look at the current ion rocket designs in NASA's portfolio or just google the topic to see what's out there. If I could do better I'd be selling it to NASA now. If you want to scale it up, put two, four, 10, 1000, ... such engines on your vehicle and figure how to power them.

 

[mfb]

Ion thrusters are limited by power. It is not that hard to design an ion thruster that uses 1 MW - but where do you get 1 MW of power from?
Using 1kg/s of propellant with typical ion thruster I_sp of 4000 s would need a power of 800 MW (at 100% efficiency). That is a full-scale nuclear reactor block on Earth. And it does not scale well: that ion thruster can only lift 4 tons to space, negligible compared to the weight of such a massive reactor.

 

[God Plays Dice]

Ok. What about pre ionised fuel? Like a compressed gas of h+ ions etc. Can you make and store a few tons of the stuff in your rocket?

 

[Vanadium 50]

Tons? Tons?

I think this thread needs to become a B. One ton of ionized hydrogen has a charge of 50 billion coulombs. Putting this much charge in such a small space would take - and immediately release - the energy of a trillion nuclear bombs. This is pure fantasy.

 

[mfb]

In addition, ionization doesn't solve the energy problem. Accelerating the stuff is the main point, and needs more energy than any non-nuclear fuel can store. Chemical rockets are quite efficient in converting chemical energy to thrust. To get higher exhaust velocities, you need a different power source - solar or nuclear power. And a lot of time, because both don't deliver the power densities a classical chemical rocket can give.

 

[ZapperZ]

In addition, ionization doesn't solve the energy problem. Accelerating the stuff is the main point, and needs more energy than any non-nuclear fuel can store. Chemical rockets are quite efficient in converting chemical energy to thrust. To get higher exhaust velocities, you need a different power source - solar or nuclear power. And a lot of time, because both don't deliver the power densities a classical chemical rocket can give.

I think when people come up with these schemes, they often forget to evaluate this factor, i.e. the efficiency of the scheme. Accelerating particles using a conventional accelerator is not the most efficient thing in the world. Couple this with the inefficient ionization process, then one is burning up more fuel to do this than the tried and true propulsion that we have already.

People forget that just because it is possible, it doesn't mean mean that it is the BEST thing to do. The economics and other factors are also involved.

Zz.

 

[God Plays Dice]

I got ideas about accelerating the stuff ;)
My only issue is getting the rate of ionisation up to 1kg/sec

 

[ZapperZ]

I got ideas about accelerating the stuff ;)
My only issue is getting the rate of ionisation up to 1kg/sec

It appears as if all the stuff that was brought up about the efficiency (or lack of it) of the scheme just fell on deaf ears!

Zz.

 

[God Plays Dice]

Can anyone suggest, if you were to do it, what would be the best method for that many particles?

 

[Vanadium 50]

Magic.

 

[Dale]

The method is no mystery. Simply get a large anode, a large cathode, a very high voltage, and a lot of ionizable gas. The method is not mysterious, it just requires a lot of power as has been mentioned above.

 

[God Plays Dice]

Ok cheers.

 

[God Plays Dice]

I really had no idea about this, whether you should heat it or shoot it with electrons or photons so thanks

 

[God Plays Dice]

What stops the ions reacting with the cathode?

 

[God Plays Dice]

Can you coat it?

 

[mfb]

Please stop making multiple posts, you can edit the previous ones.
You clearly don't have the required knowledge to design any useful ionization device. You can look up how existing ones work to answer questions like that, but as I said: ionization is not the main issue. You claim to have ideas about acceleration, but you cannot violate energy conservation: those ideas won't work.

 

[Vanadium 50]

God Plays Dice, you are talking to yourself. Apart from posting four messages in a row, you're not listening to what other people are telling you. There simply isn't enough energy available on the planet to do what you want.