Controlled generation of short-wavelength periodic megagauss magnetic fields in plasmas

We examine the possibility of producing short-wavelength MG magnetic fields by exciting a magnetic mode from the collision of electromagnetic light pulses with relativistic ionization fronts. PIC simulation results demonstrate the validity of the scheme to generate compact coherent long lived magnetic structures that can be used to produce ultrashort-wavelength radiation with existing state-of-the-art laser systems. In particular, we analyze the possibility of making a compact Gamma-ray synchrotron source based on this magnetic mode.