Suppose $R=k[[x_1,...,x_n]]$ is a formal power series ring over the field $k$, what can we say about the structure of $R/p$ if $p$ is a prime ideal of $R$ such that dim$(R/p)=1$. In particular, are these subrings of power series rings in one variable?
Motivation: Given a subring of a power series ring in one variable which can be written as, $k[[x^{a_1},...,x^{a_n}]]$ where $a_1,...,a_n$ are distinct positive integers, we have a homomorphism $k[[x_1,...,x_n]]\to k[[x^{a_1},...,x^{a_n}]]$ which sends $x_i\to x^{a_i}$. The kernel of this homomorphism must be a prime ideal since $k[[x^{a_1},...,x^{a_n}]]$ is a domain. Moreover, the quotient modulo the kernel must be one dimensional since the image ring is one dimensional. I was wondering if we have a (partial) converse to this result. (I do realize the second paragraph would analogously work with polynomial rings, but it seems power series rings and much nicer (they are regular and local), so I was hoping for a nicer description of the quotient in the power series case).