WATER FRAGMENTATION BY BARE AND DRESSED LIGHT IONS WITH MEV ENERGIES

H. LUNA; F. TURCO; W. WOLFF; S. SUÁREZ; N. D. CARIATORE; H. LUNA; D. FREGENAL; F. TURCO; W. WOLFF; S. SUÁREZ; N. D. CARIATORE; D. FREGENAL; R. SCHUCH; S. OTRANTO; G. BERNARDI; R. SCHUCH; S. OTRANTO; G. BERNARDI

Kielce

Conferencia; 18th International Conference on Physics of Highly charged ions; 2016

The report presents data on the ionization and fragmentation of water induced by H+, Li0-3+,and C1,2+ impact in the intermediate energy range of 1.6 to 5.8 MeV, with focus on the energyand time-of-flight distributions of water ionic fragments. Two experimental approachesbased on an electrostatic spectrometer were applied to investigate the fragmentation channels,in one case fragment-ion energy distributions were recorded, while in the second setup, thePelletron accelerator was operated in pulse mode and the spectrometer acted as a time offlight spectrometer. The experimental findings were compared to a model based on Classicaltrajectory Monte carlo calculations which were married to a coulomb Explosion Model.The combined experimental and theoretical study reveals isotropic production of charged ionsand show, besides the most abundant H+ ions, highly-charged Oq+ fragments with charges upto 5+. From the ion energy distribution and time of flight spectra relative yields of thedissociation resulting from multiple-ionization were extracted as function of neutral to bareprojectiles, for several projectile energies, and fragment-ions energies, probing distinct scopesof the water fragmentation. the calculations indicate that close collisions between theprojectile and the target atoms lead to multiple ionization and can be related to the oq+population. although there are studies concerning the influence of the velocity and chargestate of the projectile on the dissociation of water, a detailed knowledge of features of thedissociation pattern leading to the formation of multiply charged ion-pairs in the intermediateenergy range remains scarce.