Can you find the names of the letters of the Greek alphabet in the array of letters below?

The names appear forward, backward, up, down, and diagonally.



Here is a list of the Greek letters:
    Alpha     Iota     Rho
    Beta     Kappa     Sigma
    Gamma     Lambda     Tau
    Delta     Mu     Upsilon
    Epsilon     Nu     Phi
    Zeta     Xi     Chi
    Eta     Omicron     Psi
    Theta     Pi     Omega