# Homework Help: Length of time to burn fuel in a fusion reactor

1. Jun 3, 2013

### clarinethero

If I have a fusion reactor running at some designated power output (let's say, for instance, 5x10^8 Watts), how can I find how long it takes to burn a fuel source provided I know the composition of the fuel. For this example, let me just say I have half deuterium and half tritium?

I'm not really sure how to approach this. Any assistance would be appreciated.

Last edited: Jun 3, 2013
2. Jun 3, 2013

### Staff: Mentor

You can check the fusion yield per fusion process (via the particle masses, or just look it up), and you can check the mass of the fusing particles.

Is this homework? Then it should go to the homework section, and written according to the homework template.

3. Jun 3, 2013

### clarinethero

I understand I can find the energy output from the fusion of deuterium and tritium by finding the mass deficit. This got me 2.818x10^-12 J for the reaction, but the numerical details are not important. I was going to do what you mentioned, so I'm good to go I think.

My only remaining question is: The amount of time it would take is dependent on how much fuel I have, correct? Worded differently, my answer is going to be a function of mass of fuel? I'd imagine that the more fuel I have the longer it would take to burn to completion given a constant power output.

I wasn't sure where to post this, but it's not homework. It's the summer and school's out for me (I'm also not a physics major, hence me asking this), but I'm trying to learn more about more about fusion and plasma. So, to do so I found a question that, in it, had my original question and was unsure how to approach it. Maybe it would have been better to post in the homework help section anyway. I also made up the numbers.

Last edited: Jun 3, 2013
4. Jun 4, 2013

### Staff: Mentor

It definitely qualifies as a homework like question.

5. Jun 4, 2013

Noted