Measurement of characteristic parameters and self-generated electric and magnetic fields (SGEMFs) of laser-induced aluminum plasma

Abstract

The characteristic parameters as well as self-generated electric and magnetic fields of Nd:YAG laser (532 nm, 10 ns) ablated Al plasma have been measured by employing Langmuir, electric and magnetic probes, respectively. Plasma parameters such as electron temperature ( $${T}_{e}$$ ) and electron number density ( $${n}_{e}$$ ) as well as SGEMFs of Al plasma are measured as a function of laser irradiance ranging from 5.2 to 9.4 GW/cm2 at fixed probes to target distance of 10 mm. Both $${T}_{e}$$ and $${n}_{e}$$ of Al plasma show an increasing trend with the increase of laser irradiance and vary from 8 to 11 eV and 3.9 × 1014 to 7.07 × 1014/cm3, respectively. The SGEMFs show an overall increasing trend with the increase of laser irradiance and a decreasing trend with increasing probe to plume distances. The evaluated values of SGEMFs vary from 50 to 380 V/m and 89 to 165 G. The growth of SGEMFs has been explained on the basis of quadrupole distribution of charges at leading and trailing fronts of expanding plasma. By controlling plasma parameters such as electron temperature and electron density, laser generated plasmas can be efficiently used as sources of pulsed electric and magnetic fields in wake field accelerators.