Correlation functions of light charged particles from projectile-like fragment source in and 77 MeV 40Ar + 27Al collisions

Ghetti, R.; Helgesson, J.; Lanzanó, G.; Filippo, E. De; Geraci, M.; Aiello, S.; Cavallaro, S.; Pagano, A.; Politi, G.; Charvet, J. L.; Dayras, R.; Pollacco, E. C.; Volant, C.; Beck, Christian; Mahboub, D.; Nouicer, R.

doi:10.1016/j.nuclphysa.2005.11.019

Cited by 9 publications

(4 citation statements)

References 38 publications

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“…Particle-particle correlations [23][24][25], velocity correlations [26][27][28][29], fission fragment angular distributions [30], and Coulomb proximity affects [21,22,[31][32][33] have been used in attempts to extract information on the emission time of fragments. The proximity of the PLF and TLF to the midrapidity LCPs can be exploited to provide information on their emission time since particles emitted at early stages in the reaction will feel an increased Coulomb potential due to the increased proximity.…”

Section: Introductionmentioning

confidence: 99%

Correlations with projectile-like fragments and emission order of light charged particles

et al. 2012

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Correlations of midrapidity light charged particles (LCPs) and intermediate mass fragments (IMFs) with projectile-like fragments (PLFs) have been examined from the 35 MeV/u 70 Zn + 70 Zn, 64 Zn + 64 Zn, and 64 Ni + 64 Ni reaction systems. A new method was developed to examine the flow of the particles with respect to the PLF. The invariant PLF-scaled flow allowed for the dynamics of the midrapidity Z = 1-4 particles to be studied. Strong differences in the PLF-scaled flow were observed between the different isotopes. In particular, the most n-rich LCPs exhibited a negative PLF-scaled flow in comparison to the other LCPs. A classical molecular dynamics model and a three-body Coulomb trajectory simulation were both used to show that the PLF-scaled flow observable could be connected to the average order of emission of the LCPs. The experimental results suggest that the midrapidity region is preferentially populated with neutron-rich LCPs and Z = 3-4 IMFs at a relatively early stage in the collision. The deuteron and 3 He particles are emitted later followed, lastly, by protons and alphas. The average order of emission of the midrapidity LCPs was extracted from the constrained molecular dynamics simulations and showed good agreement with the emission order suggested by the experimental PLF-scaled flow results.

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Section: Introductionmentioning

confidence: 99%

Correlations with projectile-like fragments and emission order of light charged particles

et al. 2012

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“…The choice of a lighter system for investigation has the advantage of reducing the Coulomb contributions. Earlier investigations in this mass region have provided valuable insights into the binary reaction mechanism [33][34][35][36][37][38], multifragment emission as a function of excitation energy [39][40][41][42][43][44][45], the emission time scale and emission sequence of light particles [46][47][48] and collective flow behavior [49], and so on.…”

Section: Introductionmentioning

confidence: 99%

Critical behavior in light nuclear systems: Experimental aspects

G.¹,

Natowitz²,

Wada³

et al. 2005

Phys. Rev. C

102

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An extensive experimental survey of the features of the disassembly of a small quasiprojectile system with A ∼ 36, produced in the reactions of 47 MeV/nucleon 40 Ar + 27 Al, 48 Ti, and 58 Ni, has been carried out. Nuclei in the excitation energy range of 1-9 MeV/nucleon have been investigated employing a new method to reconstruct the quasiprojectile source. At an excitation energy ∼5.6 MeV/nucleon many observables indicate the presence of maximal fluctuations in the deexcitation processes. These include the normalized second moments of the Campi plot and normalized variances of the distributions of order parameters such as the atomic number of the heaviest fragment Z max and the total kinetic energy. The evolution of the correlation of the atomic number of the heaviest fragment with that of the second heaviest fragment and a bimodality test are also consistent with a transition in the same excitation energy region. The related phase separation parameter, S p , shows a significant change of slope at the same excitation energy. In the same region a -scaling analysis for of the heaviest fragments exhibits a transition to = 1 scaling, which is predicted to characterize a disordered phase. The fragment topological structure shows that the rank-sorted fragments obey Zipf's law at the point of largest fluctuations, providing another indication of a liquid gas phase transition. The Fisher droplet model critical exponent τ ∼ 2.3 obtained from the charge distribution at the same excitation energy is close to the critical exponent of the liquid gas phase transition universality class. The caloric curve for this system shows a monotonic increase of temperature with excitation energy and no apparent plateau. The temperature at the point of maximal fluctuations is 8.3 ± 0.5 MeV. Taking this temperature as the critical temperature and employing the caloric curve information we have extracted the critical exponents β, γ , and σ from the data. Their values are also consistent with the values of the universality class of the liquid gas phase transition. Taken together, this body of evidence strongly suggests a phase change in an equilibrated mesoscopic system at, or extremely close to, the critical point.

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“…The ordering observed in Fig. 1 may be due to different average emission times for the different particles [36][37][38][39]. The tritons and helions are "expensive" particles, as the energy cost (Q-value) for their emission from an excited source (Q ≈ 20 MeV) is high relative to protons and α particles (Q ≈ 10 MeV).…”

Section: Resultsmentioning

confidence: 99%

Using light charged particles to probe the asymmetry dependence of the nuclear caloric curve

et al. 2013

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Recently, we observed a clear dependence of the nuclear caloric curve on neutron-proton asymmetry N−Z A through examination of fully reconstructed equilibrated quasi-projectile sources produced in heavy ion collisions at E/A = 35 MeV. In the present work, we extend our analysis using multiple light charged particle probes of the temperature. Temperatures are extracted with five distinct probes using a kinetic thermometer approach. Additionally, temperatures are extracted using two probes within a chemical thermometer approach (Albergo method). All seven measurements show a significant linear dependence of the source temperature on the source asymmetry. For the kinetic thermometer, the strength of the asymmetry dependence varies with the probe particle species in a way which is consistent with an average emission-time ordering.

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Correlation functions of light charged particles from projectile-like fragment source in and 77 MeV 40Ar + 27Al collisions

Cited by 9 publications

References 38 publications

Correlations with projectile-like fragments and emission order of light charged particles

Correlations with projectile-like fragments and emission order of light charged particles

Critical behavior in light nuclear systems: Experimental aspects

Using light charged particles to probe the asymmetry dependence of the nuclear caloric curve

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