Reporting from NIC 2012:
Over the last 60 years nuclear physicists have been measuring nuclear reaction cross sections for many nuclides. With time accelerators became bigger and bigger going from MeV to GeV to TeV in energies and they are now in the energy range to recreate the temperature and densities of just after the Big Bang.
This trend was actually counter-productive for the astrophysicists who model the nucleosynthesis in stars. Stellar fusion temperatures are in the range of millions to billions degrees but the corresponding energies are only in the KeV range This is well below the energy ranges which have been analyzed to date, which leaves a lot of gaps and uncertainties in the data.
A new trend is to explore these low energy ranges which has it’s own difficulties. Accelerators are easy to build but the reaction rates are very low and there might only be a handful of counts during a day or week. This means that background counts have to be suppressed as good as possible. The main source for background interference are cosmic rays so the only way around this is going underground like the laboratories in the Gran Sasso massif.