The goals of nuclear astrophysics are understanding the energy generation in stars in all stages of stellar evolution and explaining the abundances of the elements and their isotopes as we observe them in nature. These aims are closely related since nuclear processes have been identified as the enormous energy source which stabilizes the stars and governs their evolution by transmuting nuclear species into other nuclear species thus simultaneously creating new elements.

Performing accurate measurements of nuclear reaction rates of proton and alpha burning processes is essential for the correct understanding of many astrophysical processes, such as stellar evolutions, supernova explosions and Big Bang nucleosynthesis, etc.

Direct and indirect measurements of the relevant cross sections have been performed over the years. Direct measurements using accelerated beams show that, at very low energies, the electrons in the target’s atoms partially screen the Coulomb barrier between the projectile and the target [SAL54], resulting in an enhancement of the measured cross section compared with the bare nucleus cross section [NACRE]. The electron screening effect is significantly affected by the target conditions and composition [LIP10], it is of particular importance the measurement of cross-sections at extremely low energetic domains including plasmas effect, i.e. in an environment that under some circumstances and assumptions can be considered as “stellar-like” (for example, for the study of the role played by free/bounded electrons on the coulombian screening can be done in dense and warm plasmas).

Electron screening prevents a direct measurement of the bare nucleus cross section at the energies of astrophysical interest. In the last decade, the bare cross section has been successfully measured in certain cases by using several indirect methods [SPI11].

Usually, astrophysical relevant reactions are performed in the laboratories with both target and projectile in their ground state. However, at temperatures higher than about 108K, an important role can be also played by the excited states, as already deeply discussed in the pioneering theoretical work of Bahcall and Fowler [BAH69]. In that case, the authors studied the influence of low lying excited 19F states on the final 19F(p,alpha) reaction, predicting an increase of a factor of about 3 in reaction rate at temperatures of about 1-5 GK.

Thus determining the appropriate experimental conditions that allow to evaluate the role of the excited states in the stellar environment could strongly contribute to the development of nuclear astrophysics. The study of direct measurements of reaction rates in plasma offers this chance. In addition others new topics can be conveniently explored such as three body fusion reactions as those predicted by Hoyle [HOY46], lifetime changes of unstable elements [LIM06] or nuclear and atomic levels [HAN07] in different plasma environments; other fundamental physics aspects like non-extensive statistical thermodynamics [TSA99] can be investigated in order to validate/confute the general assumption of local thermal equilibrium that is traditionally done for plasmas.

The future availability of high-intensity laser facilities capable of delivering tens of peta-watts of power (e.g. ELI-NP) into small volumes of matter at high repetition rates will give the unique opportunity to investigate nuclear reactions and fundamental interactions under the extreme conditions of density and temperature that can be reached in laser generated plasmas [MAS10], including the influence of huge magnetic and electric field, shock waves, intense fluxes of X and g-ray originated during plasma formation and expansion stages.

We propose to study nuclear reactions at low energies inside dense and energetic plasmas generated in the laboratory at unprecedented conditions thanks to the unique characteristics foreseen at the future high power laser facility. The proposed approach offers also the possibility to investigate other new topics, e.g. three body fusion reactions, variations of unstable elements nuclear and atomic levels lifetime, etc. To perform these studies we plan to set-up an experimental configuration based on two laser beams generating two colliding plasmas. Our purpose is to detect the neutrons produced by nuclear reactions inside the resulting plasma by a custom designed new and very performingdetection system.

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