title: High-resolution measurements of the spatial and temporal evolution of megagauss magnetic fields created in intense short-pulse laser-plasma interactions.
abstract: A pump-probe polarimetric technique is demonstrated, which provides a complete, temporally and spatially resolved mapping of the megagauss magnetic fields generated in intense short-pulse laser-plasma interactions. A normally incident time-delayed probe pulse reflected from its critical surface undergoes a change in its ellipticity according to the magneto-optic Cotton-Mouton effect due to the azimuthal nature of the ambient self-generated megagauss magnetic fields. The temporal resolution of the magnetic field mapping is typically of the order of the pulsewidth, limited by the laser intensity contrast, whereas a spatial resolution of a few μm is achieved by this optical technique. High-harmonics of the probe can be employed to penetrate deeper into the plasma to even near-solid densities. The spatial and temporal evolution of the megagauss magnetic fields at the target front as well as at the target rear are presented. The μm-scale resolution of the magnetic field mapping provides valuable information on the filamentary instabilities at the target front, whereas probing the target rear mirrors the highly complex fast electron transport in intense laser-plasma interactions.
authors: Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005, India.
authors: Gourab
authors: G
authors: Chatterjee
authors: Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005, India.
authors: Prashant Kumar
authors: PK
authors: Singh
authors: Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005, India.
authors: Amitava
authors: A
authors: Adak
authors: Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005, India.
authors: Amit D
authors: AD
authors: Lad
authors: Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005, India.
authors: G Ravindra
authors: GR
authors: Kumar