- #1
Eminator
- 3
- 1
Hi there,
I have been in the field of Nuclear Fusion for a couple of years now and while there are some good scientists there is a significant amount of questionable research practices around and I would like to hear your opinion on this as I am increasingly frustrated.
I would like to illustrate this on the example of a particle balance called the coronal equilibrium. In Tokamaks, it would be necessary to use transport codes in order to infer the distribution of ionized states of an element. However, it is common practice to use a non-transport ionization balance of recombination and ionization called coronal equilibrium. See for example here for a reasonable critical paper that I still don't like.
Not only is a coronal euilibrium wrong because the recombination happens at or close to the target, but even the values can be orders of magnitude wrong. This is even stated in this older paper: the plasma is far out of coronal equilibrium at the edge.
There are some efforts to correct the coronal equilibrium for transport effects like in this or this paper, but these models are still too overly simplified. One paper that I really don't like is this one. All it says on the matter is "is calculated using a zero-transport ionisation balance.", no discussion what so ever if this is correct.
The only reason his values are kind of reasonable is because he measures the plasma to be 3.5 eV. Between 3.3 and 3.7 eV the coronal equilibrium delivers approximately 100% for the fraction of the regarded charge state and is therefore a reasonable value (correct would be like 10-60% though). Upon confrontation the author replies "Firstly, transport I concluded was not important specifically for this geometry and high power Hmode". Yeah, exactly, it works for your very one experiment, of course...
Also simulations show that transport is important, just the values of a coronal equilibrium gives an order of magnitude correct guess in the mentioned temperature range. When confronting other researchers they also don't like the paper particularly much. Others tell me being a Scientist is a hard job and being honest is even harder. Others say, make a better model and you will get the reward. What do you think about this?
I have been in the field of Nuclear Fusion for a couple of years now and while there are some good scientists there is a significant amount of questionable research practices around and I would like to hear your opinion on this as I am increasingly frustrated.
I would like to illustrate this on the example of a particle balance called the coronal equilibrium. In Tokamaks, it would be necessary to use transport codes in order to infer the distribution of ionized states of an element. However, it is common practice to use a non-transport ionization balance of recombination and ionization called coronal equilibrium. See for example here for a reasonable critical paper that I still don't like.
Not only is a coronal euilibrium wrong because the recombination happens at or close to the target, but even the values can be orders of magnitude wrong. This is even stated in this older paper: the plasma is far out of coronal equilibrium at the edge.
There are some efforts to correct the coronal equilibrium for transport effects like in this or this paper, but these models are still too overly simplified. One paper that I really don't like is this one. All it says on the matter is "is calculated using a zero-transport ionisation balance.", no discussion what so ever if this is correct.
The only reason his values are kind of reasonable is because he measures the plasma to be 3.5 eV. Between 3.3 and 3.7 eV the coronal equilibrium delivers approximately 100% for the fraction of the regarded charge state and is therefore a reasonable value (correct would be like 10-60% though). Upon confrontation the author replies "Firstly, transport I concluded was not important specifically for this geometry and high power Hmode". Yeah, exactly, it works for your very one experiment, of course...
Also simulations show that transport is important, just the values of a coronal equilibrium gives an order of magnitude correct guess in the mentioned temperature range. When confronting other researchers they also don't like the paper particularly much. Others tell me being a Scientist is a hard job and being honest is even harder. Others say, make a better model and you will get the reward. What do you think about this?