SECAR



Overview

The Separator for Capture Reactions (SECAR) will be a recoil separator at FRIB that is optimized for measurements of low-energy capture reactions of importance for nuclear astrophysics. It will be installed in the ReA3 (low-energy reaccelerated beams) Hall at the Facility for Rare Isotope Beams (FRIB) at Michigan State University. Measurements with SECAR will focus on capture reactions needed to improve our understanding of novae, X-ray bursts, supernovae, and other astrophysical enbironments. SECAR is designed to have a performance that significantly exceeds that of all previous recoils separators used for astrophysics measurements. It is the flag ship experiment for the FRIB nuclear astrophysics community, and has been repeatedly reaffirmed as this community's highest priority on numerous occasions.

Approach

Reaccelerated proton-rich unstable beams will bombard an H or He gas target. The overwhelming majority of the beam particles will pass through the target with no interaction and will enter the SECAR separator system which is aligned along the beam axis. Approximately one projectile out of 1011 to 1017 will undergo a capture reaction with a beam particle and form a capture-reaction recoil which enters the separator along with the intense background of unreacted projectiles. SECAR employs two velocity filters (crossed electric and magnetic field devices) to transport the recoils to a focal plane for detection while steering away the unreacted projectiles. A proof-of-principle study at Caltech in 1991 showed the viability of this approach with a stable beam. Subsequent measurements with other devices the DRAGON separator at TRIUMF ISAC and the Daresbury Recoil Separator (DRS) at ORNL HRIBF showed the capability to measure capture reaction recoils using radioactive beams. The rejection of the SECAR separator with its focal plane detector is projected to be as high as 1017.

Status

After successful reviews in Summer 2014 (external experts), October 2014 (DOE-SC/NSF), and January 2015 (DOE-SC/NSF), the SECAR project officially began on March 1, 2015 via funding through the Office of Nuclear Physics from the DOE Office of Science. The project is currenty on budget and on schedule to deliver SECAR by 2022, and we are managing the project to early completion in 2020.

Current activity

Specifications for the magnet system (magnets, velocity filters, and associated power supplies) have been written and put out for bid, and a number of bids received from vendors. We are currently (August 2015) evaluating the bids in preparation to select the vendor(s) for these major procurements in September 2015.

Funding

Phase 1 of the project has been funded at $9.3M by Office of Nuclear Physics from the DOE Office of Science. We will seek funding for SECAR Phase 2 for $2.4M via a proposal to NSF Nuclear Physics. The goal is to execute both phases concurrently to reduce cost and risk.

Collaboration Council

We have established a Collaboration Council to represent the broader SECAR collaboration in the project.
The Council will
  - communicate needs of the collaboration to the project
  - communicate project information to collaboration
  - foster growth of the collaboration
  - work to ensure SECAR addresses needs of the collaboration

Current Collaboration Council Members are: Michael Smith - ORNL (Chair); Dan Bardayan - Notre Dame; Alan Chen - McMaster Univ.; Catherine Deibel - LSU; Uwe Greife - Colorado School of Mines; Ernst Rehm - ANL; Frank Strieder - South Dakota School of Mines; and Chris Wrede - MSU.

Collaboration

The SECAR collaboration currently includes nuclear astrophysics groups from Argonne National Lab, Central Michigan University, Colorado School of Mines, Louisiana State University, McMaster University, Michigan State University, University of Notre Dame, Oak Ridge National Lab, and South Dakota School of Mines. If you are interested in joining the SECAR collaboration, please contact Hendrik Schatz, schatz at nscl.msu.edu.

Presentations

"Design of a New Recoil Separator for Measurements of Radiative Capture Reactions in Astrophysics", SECAR poster abstract, OMEG10 Symposium, March 2010

"SECAR", Manoel Couder, May 2009 FRIB workshop

"Recoil Separators for Capture Reaction Measurements", Michael Smith, May 2009 FRIB workshop

"Recoil Separator", Manoel Couder, August 2008 MSU workshop

"Recoil Separators & Approaches for Low Energy Nuclear Astrophysics Measurements", Michael Smith, August 2008 MSU workshop

Poster on SECAR, May 2009 RNB8 Symposium

"Gas Target Systems", Uwe Greife, May 2009 FRIB workshop

"ANASEN", Jeff Blackmon, May 2009 FRIB workshop

Collaborators' Pages

Please click here to access the password-protected pages for the SECAR collaborators.

If you are interested in working in the SECAR collaboration, please contact Hendrik Schatz, schatz at nscl.msu.edu.