  In a superhigh magnetic field, direct Urca reactions can proceed for an
arbitrary proton concentration. Since only the electrons with high energy $E$
($E > Q$, $Q$ is the threshold energy of inverse $\beta-$decay) at large Landau
levels can be captured, we introduce the Landau level effect coefficient $q$
and the effective electron capture rate $\Gamma_{\rm eff}$. By using
$\Gamma_{\rm eff}$, the values of $L_{\rm X}$ and $L_{\rm \nu}$ are calculated,
where and $L_{\rm \nu}$, $L_{\rm X}$ are the average neutrino luminosity of
Anomalous X-ray Pulsars (AXPs) and the average X-ray luminosity of AXPs,
respectively. The complete process of electron capture inside a magnetar is
simulated numerically.
