Spatial measurements of the emission spectra of a laser-generated plasma were obtained for copper and lead targets. Results showed that the two metals gave quite different sizes of plasma, the plasma formed with copper extending 2 mm, and that with lead extending 5 mm, above the metal surface. Excitation temperatures of the plasma ranged from 13,200 to 17,200 K for copper and 11,700 to 15,300 K for lead.
Yong-Ill Lee, Samuel P. Sawan, Terry L. Thiem, Ye-Yung Teng, and Joseph Sneddon, "Interaction of a Laser Beam with Metals. Part II: Space-Resolved Studies of Laser-Ablated Plasma Emission," Appl. Spectrosc. 46, 436-441 (1992)