In measuring X-ray magnetic circular dichroism spectra by the sample current mode

signal currents are strongly affected by external fields. Aiming at the design of rotatable electromagnet inside the vacuum chamber

we have designed and installed a piece of gold mesh attached to magnetic poles to increase the sample current signals

and found that sample currents increase rapidly and tend to saturation with increasing bias in different magnetic fields. The stronger the external field is applied

the higher bias voltage is required to reach signal saturation. Comparing absorption spectra of an oxidated aluminum foil with a CoFe film in parallel and antiparallel magnetization under the same magnetic field and bias

we have found that the systematic error caused by adding magnetic field and bias is 2.17% of MCD intensity for cobalt

which indicates that the developed technique has some advantages to measure XMCD spectra.