From 16555851b6514a736c5c9d8e73de7da7fc9b6288 Mon Sep 17 00:00:00 2001 From: Prefetch Date: Thu, 20 Oct 2022 18:25:31 +0200 Subject: Migrate from 'jekyll-katex' to 'kramdown-math-sskatex' --- source/know/concept/lawson-criterion/index.md | 40 +++++++++++++-------------- 1 file changed, 20 insertions(+), 20 deletions(-) (limited to 'source/know/concept/lawson-criterion') diff --git a/source/know/concept/lawson-criterion/index.md b/source/know/concept/lawson-criterion/index.md index ff9594b..f2f2fe0 100644 --- a/source/know/concept/lawson-criterion/index.md +++ b/source/know/concept/lawson-criterion/index.md @@ -13,9 +13,9 @@ the **Lawson criterion** must be met, from which some required properties of the plasma and the reactor chamber can be deduced. -Suppose that a reactor generates a given power $P_\mathrm{fus}$ by nuclear fusion, -but that it leaks energy at a rate $P_\mathrm{loss}$ in an unusable way. -If an auxiliary input power $P_\mathrm{aux}$ sustains the fusion reaction, +Suppose that a reactor generates a given power $$P_\mathrm{fus}$$ by nuclear fusion, +but that it leaks energy at a rate $$P_\mathrm{loss}$$ in an unusable way. +If an auxiliary input power $$P_\mathrm{aux}$$ sustains the fusion reaction, then the following inequality must be satisfied in order to have harvestable energy: @@ -24,8 +24,8 @@ $$\begin{aligned} \le P_\mathrm{fus} + P_\mathrm{aux} \end{aligned}$$ -We can rewrite $P_\mathrm{aux}$ using the definition -of the **energy gain factor** $Q$, +We can rewrite $$P_\mathrm{aux}$$ using the definition +of the **energy gain factor** $$Q$$, which is the ratio of the output and input powers of the fusion reaction: $$\begin{aligned} @@ -45,12 +45,12 @@ $$\begin{aligned} = P_\mathrm{fus} \Big( \frac{Q + 1}{Q} \Big) \end{aligned}$$ -We assume that the plasma has equal species densities $n_i = n_e$, -so its total density $n = 2 n_i$. -Then $P_\mathrm{fus}$ is as follows, -where $f_{ii}$ is the frequency +We assume that the plasma has equal species densities $$n_i = n_e$$, +so its total density $$n = 2 n_i$$. +Then $$P_\mathrm{fus}$$ is as follows, +where $$f_{ii}$$ is the frequency with which a given ion collides with other ions, -and $E_\mathrm{fus}$ is the energy released by a single fusion reaction: +and $$E_\mathrm{fus}$$ is the energy released by a single fusion reaction: $$\begin{aligned} P_\mathrm{fus} @@ -59,11 +59,11 @@ $$\begin{aligned} = \frac{n^2}{4} \Expval{\sigma v} E_\mathrm{fus} \end{aligned}$$ -Where $\Expval{\sigma v}$ is the mean product -of the velocity $v$ and the collision cross-section $\sigma$. +Where $$\Expval{\sigma v}$$ is the mean product +of the velocity $$v$$ and the collision cross-section $$\sigma$$. -Furthermore, assuming that both species have the same temperature $T_i = T_e = T$, -the total energy density $W$ of the plasma is given by: +Furthermore, assuming that both species have the same temperature $$T_i = T_e = T$$, +the total energy density $$W$$ of the plasma is given by: $$\begin{aligned} W @@ -71,8 +71,8 @@ $$\begin{aligned} = 3 k_B T n \end{aligned}$$ -Where $k_B$ is Boltzmann's constant. -From this, we can define the **confinement time** $\tau_E$ +Where $$k_B$$ is Boltzmann's constant. +From this, we can define the **confinement time** $$\tau_E$$ as the characteristic lifetime of energy in the reactor, before leakage. Therefore: @@ -84,7 +84,7 @@ $$\begin{aligned} = \frac{3 n k_B T}{\tau_E} \end{aligned}$$ -Inserting these new expressions for $P_\mathrm{fus}$ and $P_\mathrm{loss}$ +Inserting these new expressions for $$P_\mathrm{fus}$$ and $$P_\mathrm{loss}$$ into the inequality, we arrive at: $$\begin{aligned} @@ -101,8 +101,8 @@ $$\begin{aligned} \end{aligned}$$ However, it turns out that the highest fusion power density -is reached when $T$ is at the minimum of $T^2 / \Expval{\sigma v}$. -Therefore, we multiply by $T$ to get the Lawson triple product: +is reached when $$T$$ is at the minimum of $$T^2 / \Expval{\sigma v}$$. +Therefore, we multiply by $$T$$ to get the Lawson triple product: $$\begin{aligned} \boxed{ @@ -112,7 +112,7 @@ $$\begin{aligned} \end{aligned}$$ For some reason, -it is often assumed that the fusion is infinitely profitable $Q \to \infty$, +it is often assumed that the fusion is infinitely profitable $$Q \to \infty$$, in which case the criterion reduces to: $$\begin{aligned} -- cgit v1.2.3