Abstract
The influence of spatial confinement on the laser induced plasma parameters of Bismuth (Bi) at different laser irradiances ranging from 2.9 GWcmâ2 to 6.2 GWcmâ2 has been investigated using Langmuir probe technique. The spatial confinement is introduced with the help of metallic blocker placing at different distances of 5 mm, 10 mm and 15 mm from the target. It is observed that electron temperature (Te), electron density (ne), and electron thermal velocity (vth,e) of Bi plasma are significantly influenced by laser irradiance, biasing voltage and blocker distances. In the absence of blocker, maximum values of Te, ne, and vth,e, are 13 eV, 1.6 Ă 1017 cmâ3 and 2.4 Ă 108 cmsâ1 respectively, whereas, in the presence of blocker these values are significantly enhanced to 31.6 eV, 2.9 Ă 1017 cmâ3 and 3.7 Ă 108 cmsâ1 respectively. This enhancement is attributed to increased collisional frequency of plasma species after compression due to reflection of shock waves from blocker. The analytical evaluated values of work done to compress plume vary from 0.7 mJ to 0.2 mJ, whereas, the variation in plasma pressures is from 0.35 MPa to 1.47 MPa and shock pressures variation comes out to be in the range from 0.32 GPa to 0.56 GPa.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have