DUSEL Nuclear Astrophysics Working Group

Collaboration Documents (password required)

Underground Accelerator Laboratory

Extracted from the Introduction of the Underground Accelerator White Paper

“We are all made of star stuff”, Carl Sagan

Each single atom in our body was processed through - on average - between fifty to hundred star generations before it condensed in our solar system - on earth - to form us. This means each atom experienced many times a supernova explosion and/or was dredged up from the interior of a deep convective low mass star to be blown into outer space, and/or was ejected in a thermonuclear explosion in a binary or massive star system before it got to us. The understanding of these nucleosynthesis processes which are driven by a large number of nuclear reaction and fusion processes is an important part for our quest about the origin of life in our universe.

One of the great successes of nuclear astrophysics is the development of a detailed model to describe stellar evolution and energy generation. However, despite 50 years of experimental efforts, only a few of the associated nuclear reactions have yet been measured close to the relevant energies. A more complete quantitative understanding of the critical reactions defining the nuclear networks would improve understanding of the generation of the elements (including those necessary for life) comprising the solar system and galaxy, supernova nucleosynthesis, and the lifetime and ultimate fate of particular classes of stars. While there are a large number of reactions governing stellar burning, a number of high priority reactions to be investigated have been identified by theoretical modeling studies of stellar burning conditions.  

High precision measurements of nuclear reaction cross-sections at low energies (at or near the Gamow window) are daunting, because at stellar energies reaction rates are extremely low.  Precise yield measurements are contaminated by background counts from beam, target, or detector impurities, from cosmic ray produced backgrounds, and from ambient laboratory material backgrounds. By moving the experiments deep underground, the cosmic ray background can be greatly reduced as demonstrated by the astrophysics accelerator laboratory LUNA in Gran Sasso.

For the purpose of establishing a state of the art underground accelerator laboratory at the Homestake mine, the DUSEL Nuclear Astrophysics Collaboration DIANA has been formed.  

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