BigRIPS separator and ZeroDegree spectrometer at RIKEN RI Beam Factory

Abstract

The BigRIPS in-flight separator, which became operational in March 2007 at the RI Beam Factory (RIBF) at RIKEN Nishina Center, has been used to produce a variety of rare-isotope (RI) beams by using in-flight fission as well as projectile fragmentation. Its major features are large ion-optical acceptances and two-stage structure. Excellent performance in particle identification is also an important feature. Efficient RI-beam production based on the in-flight scheme has been made possible by these features of the BigRIPS separator, allowing us to greatly expand the accessible region of exotic nuclei. An RI-beam delivery line following the BigRIPS separator is designed to work as a forward spectrometer, called ZeroDegree. As a major experimental device at RIBF, the ZeroDegree spectrometer has been used for a variety of reaction studies with RI beams. In this paper, we present an overview of the BigRIPS separator and the ZeroDegree spectrometer, emphasizing the capability and potential of the new-generation RI beam facility, RIBF.