Laboratories

The Laboratory for Experimental Nuclear Astrophysics (LENA)

We are utilizing local and external facilities for measurements of astrophysically important reactions. Experiments at local facilities mainly utilize the Laboratory for Experimental Nuclear Astrophysics (LENA) or the Enge magnetic spectrometer in the tandem laboratory. Other accelerators available at TUNL (such as a modified 4 MV KN accelerator and a 200 kV minitandem accelerator) are also being used by our group for certain projects. Our external efforts focus on measurements of astrophysically interesting reactions using radioactive ion beams. One of our postdocs is permanently stationed at the Holifield facility at Oak Ridge National Laboratory.

Take a Tour of the Lab by Clicking on Sections of the Pictures Below!



		The Laboratory for Experimental Nuclear Astrophysics (LENA) We are utilizing local and external facilities for measurements of astrophysically important reactions. Experiments at local facilities mainly utilize the Laboratory for Experimental Nuclear Astrophysics (LENA) or the Enge magnetic spectrometer in the tandem laboratory. Other accelerators available at TUNL (such as a modified 4 MV KN accelerator and a 200 kV minitandem accelerator) are also being used by our group for certain projects. Our external efforts focus on measurements of astrophysically interesting reactions using radioactive ion beams. One of our postdocs is permanently stationed at the Holifield facility at Oak Ridge National Laboratory. Take a Tour of the Lab by Clicking on Sections of the Pictures Below!

















		The LENA facility is used for directly measuring astrophysically important cross sections and resonance strengths at low bombarding energies. LENA consists of two major components, a 1 MV JN accelerator and a 200 kV accelerator. Both accelerators deliver protons or alpha-particles into the same beamline. The smaller machine provides currents of up to 1 mA on target (this is a crucial requirement for measuring very weak cross sections at low bombarding energies), while the larger accelerator is used for periodically checking the target stability (for example, by measuring well-known resonances located at higher energies).

		The Enge Magnetic Spectrometer In certain situations, it it not possible to measure an astrophysically important reaction directly (for instance, if the target nucleus is short-lived, or if the the bombarding energy is too low). In these cases we study the level structure of the corresponding compound nuclei at higher energies by using stripping [3He,d),(d,p), etc.] or charge-exchange reactions [(3He,t)]. From the measured nuclear structure properties we then deduce the thermonuclear reaction rates of interest. The Enge spectrograph is an important tool for these spectroscopy studies. It is designed to focus outgoing particles from nuclear reactions onto the focal plane, while changing the spread in energy into a spread in position. The energy resolution measured in typical (p,p), (3He,d) or (d,p) reactions amount to a few keV only (an important requirement for measuring precise excitation energies of nuclear levels). Furthermore, the solid angle of our spectrograph is rather large (about 10 msr), making it useful for particle-particle and particle-gamma coincidence studies. View the Spectrometer by Clicking on Sections of the Picture Below



		The LENA Espresso Machine



		Bob Runkle Serving Espresso to his Esteemed Colleagues