Inertial confinement fusion hotspots and cluster Coulomb explosion plasmas may develop a positive net electric charge. The Coulomb barrier penetrability and the rate of nuclear fusion reactions at ultra-low energies ( 10 keV) are altered by such an environment. These effects are here studied via the screening potential approach. Approximate analytical results are developed by evaluating the average screening potential for some scenarios of interest. It is found that fusion is hindered for reactions between thermal fuel nuclei, while an enhancement is expected for secondary and "beam-target" reactions. Depending on the plasma conditions, the variations can be relevant even for relatively small net charges (several % difference or more in the fusion rate for an average net charge per nucleus of 10 −5 proton charges).

Abstract. Proper selection of the quasi-free (QF) break-up channel in a three-body reaction is a key aspect for the applicability of the Trojan Horse Method (THM). The TreimanYang (TY) Criterion is a model-independent experimental test for the dominance of the QF mechanism, and hence constitutes one of the strongest validity tests of the THM. An experiment was performed at LNS to apply the test to the d( B 10 , Be 7 α) n reaction. Here, the criterion is described and some preliminary data from the experiment are shown.