| Popis: |
Since recently researchers at UFOLAB Group, Bilkent University discovered a new regime of ultrafast laser material processing which they named ablation-cooled material removal that utilizes very high repetition rate pulses [1], ultrashort pulses at GHz repetition rates have been attracting a lot of attention with respect to industrial material processing. Ablation cooling here refers to the method which has been used for the atmospheric reentry of rockets since 1950’s where a sacrificial layer is used to protect the rockets from burning and as a term it was first used in a 1934 novel “Triplanetary,” by E.E. ‘Doc’ Smith. In this regime, cooling of the material takes place simultaneously with ablation under the bombardment of pulses repeated with a period short enough so that relatively limited heat diffusion can take place from the targeted area to the surroundings. The targeted material heats with each successive pulse up to the critical temperature required for the evaporative removal, and the ablation takes place removing a major portion of the thermal energy localized at the targeted spot. |
