Fusor Forums

I would like to compare existing fusion technologies and attempts based on their Q factor.

I searched the web but I didn't find too many numbers.

The only number is know the record 1.25 which is reached by the JT-60 tokamak using D-T fusion. They didn't...

What was the best Q number reached by IEC?

It would be nice if we can build a reference of Q numbers.

Calmarius wrote:The only number is know the record 1.25 which is reached by the JT-60 tokamak using D-T fusion.

You have an impressive record searching skill, seeing as JT-60 does not have tritium handling capability. Maybe you can find the Q of ITER on record?

OK, just misread the sources...

"As of 1998, a higher Q of 1.25 is claimed for the JT-60 tokamak; however, this was not achieved under real D-T conditions but extrapolated from experiments performed with a pure deuterium (D-D) plasma." pfff... No breakeven then.

Nope. And if you add in the energy required to set the magnetic fields in these reactors going, the Q begins to look very poor indeed. They don't bother to count that energy consumption, though. I wonder why not?

Break even will easily be reached and surpassed. It really means little. 10X breakeven would mean little as a 50 megawatt coal fired plant would have to be built next to a far larger plant to power a 500megawatt fusion reactor.

What is key to any fusion process is can a breakeven fusion system run days, weeks, months, years without interruption. Most don't realize this can't be done and hasn't been done yet even with a system producing 100% of the input energy as output. (breakeven, 1X, zero excess energy and zero losses)

Richard Hull

What is key to any fusion process is can a breakeven fusion system run days, weeks, months, years without interruption. Most don't realize this can't be done

Can you tell me which law of physics prohibits the sustained running of a fusion powered reactor? I just want to learn.

Short answer, none, but at current understand and skill of fabrication, I would take a guest and say chance of collision, I suppose if you lined up all the D and fired one bullet it might work.

Haven't slept in 24hours so might not make sense.

The simple answer is that we can't contain and compress fusion fuel while getting it hot enough to fuse without heroic efforts. When we can, it comes at the cost of the amount of time we can hold it there (NIF). There's something called the triple product (as related to the Lawson criteria) you should look into. Tokamaks so far have come closest to satisfying those criteria, though with relatively low density plasma at extreme temperatures. While no breakeven has yet been demonstrated, that's not really the holy grail as others have pointed out. Really, what we're looking for is ignition- the point when the energy liberated by fusion is sufficient to keep the plasma lit without a large external energy input.

....and for andy:
https://www.youtube.com/watch?v=5hfYJsQAhl0

I can't edit my post, but would like to clear somethings up.
Q)How can you have 50/50% if you would like a max off 66%
One of the ions in the random group, might be going in the same direction as the order

Say you have two groups each with 3 ions, one group is type of fixed in a box, when a ion hits the wall it appears in another part of the box wall and travels randomly at some random speed.
You then have the second group with three ions in a row that are traveling at the same speed towards this box, if the entropy is 50/50 in the box, you have a max probability that 66% that there will be one collision, but it doesn't mean fuse.

Also the three ions doesn't mean that all three have to hit at the same time, two can or none
i1+i2
i2+i3
i1+i3
i1+i2+i3
!=i1+i2+i3

My post is meant to be a overview, as most fusion research is aimed at making order, static e-m fields removing instability etc, if you take the max values, 33%*0.1-1%entropy(same for a little bit of randomness) is about 0.6-6.6% chance of collision, at it will get worst by the looks of it.

Andy,

We have tried to give you some latitude in your posts but it is clear that you are filling the forum with word salads that have little or no scientific basis. Maybe you think it is showing knowledge but intact shows just the opposite. Consider this your only friendly warning to post concise relevant information or risk having your posting privileges revoked.

Thank you.

Frank Sanns
Forum Administrator

Above post is a word salad to be erased.......real soon now.

New rule 100% of all of Andy's future posts will be erased at first sight by me if they are word salads with gibberish thrown in for good measure.

Richard Hull