ATHENA: An active target detector for the measurement of total cross sections

Experimentally determined cross sections are a critical input for accurately modeling the nuclear processes that take place in a variety of astrophysical environments. A new detector has been designed and constructed to measure the total cross section of nuclear reactions relevant for astrophysics. The Active Target High Efficiency detector for Nuclear Astrophysics (ATHENA) has been constructed and commissioned by a measurement of the 12C +12C fusion reaction. As an active target detector with a segmented anode, efficient measurements of total cross sections over a wide energy range are possible.