Negative heat capacity in the critical region of nuclear fragmentation: an experimental evidence of the liquid-gas phase transition

M. D'Agostino; F. Gulminelli; Ph. Chomaz; M. Bruno; F. Cannata; R. Bougault; N. Colonna; F. Gramegna; I. Iori; N. Le Neindre; G. V. Margagliotti; P. F. Mastinu; P. M. Milazzo; A. Moroni; G. Vannini

doi:10.1016/s0370-2693(99)01486-0

arXiv · nucl-ex/9906004

Negative heat capacity in the critical region of nuclear fragmentation: an experimental evidence of the liquid-gas phase transition

M. D'Agostino·F. Gulminelli·Ph. Chomaz·M. Bruno·F. Cannata·R. Bougault·N. Colonna·F. Gramegna·I. Iori·N. Le Neindre·G. V. Margagliotti·P. F. Mastinu·P. M. Milazzo·A. Moroni·G. Vannini

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Abstract

An experimental indication of negative heat capacity in excited nuclear systems is inferred from the event by event study of energy fluctuations in $Au$ quasi-projectile sources formed in $Au+Au$ collisions at 35 A.MeV. The excited source configuration is reconstructed through a calorimetric analysis of its de-excitation products. Fragment partitions show signs of a critical behavior at about 5 A.MeV excitation energy. In the same energy range the heat capacity shows a negative branch providing a direct evidence of a first order liquid gas phase transition.

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M. D'Agostino, F. Gulminelli, Ph. Chomaz, M. Bruno, F. Cannata, R. Bougault, N. Colonna, F. Gramegna, I. Iori, N. Le Neindre, G. V. Margagliotti, P. F. Mastinu, P. M. Milazzo, A. Moroni, G. Vannini. 1999-06-07. Negative heat capacity in the critical region of nuclear fragmentation: an experimental evidence of the liquid-gas phase transition. https://doi.org/10.1016/s0370-2693(99)01486-0

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