NSCL and Physics and Astronomy Department, Michigan State University Joint Institute for Nuclear Astrophysics

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1 National Superconducting Cyclotron Laboratory An overview Ana D. Becerril NSCL and Physics and Astronomy Department, Michigan State University Joint Institute for Nuclear Astrophysics University of North Carolina September, 2009

2 Science at NSCL Exploring the nuclear landscape Nuclear Theory JINA Nuclear Astrophysics Accreting Neutron Stars Equation of State of Dense Matter r-process rp-processprocess Supernovae Accelerator Physics

3 The experimental area 300 feet beam switchyard S800 spectrograph K500 cyclotron A1900 fragment separator K1200 cyclotron Adapted from Z. Constan, NSCL

4 Coupled Cyclotron Facility

5 Ion Sources magnet NSCL uses Electron Cyclotron Resonance (ECR) sources, which trap stable atoms and ionize them through h collisions i with electrons, which are kept in motion by microwaves. We have 3 ECR sources: SC-ECR ARTEMIS SuSI Adapted from Z. Constan, NSCL

6 The K500 Cyclotron Year completed: 1982 (the world s first superconducting cyclotron) Diameter: 10 ft Weight: 100 tons Magnetic field: 3-5 Tesla Superconducting wire coil: 20 miles long, carrying 800 amps Maximum energy it can impart to a proton: 500 MeV Adapted from Z. Constan, NSCL

7 The K1200 Cyclotron Completed 1988: the world s second-highestenergy cyclotron Pre-accelerated ions from K500 pass through a stripper foil in the K1200, increasing ionization and improving accelerating efficiency. Nuclei lileaving the K1200 can reach 0.5 c (typically 150 MeV/nucleon). Dees charged to 140 kv, alternated at 23 MHz. Adapted from Z. Constan, NSCL

8 Fragment production and separation 86 Kr Adapted from A. Stolz, NSCL

9 Fragment production and separation Adapted from A. Stolz, NSCL

10 Fragment production and separation A1900 Fragment Separator Separation method based on magnetic-rigidity analysis and energy-loss in degrader materials. 4 dipoles (for bending, spreading) 8 quadrupole triplets (for focusing) Adapted from A. Stolz, NSCL

11 Fragment production and separation Adapted from A. Stolz, NSCL

12 Fragment production and separation Adapted from A. Stolz, NSCL

13 Fragment production and separation

14 The A1900 fragment separator

15 Fragment production and separation

16 Beams of proton rich nuclei Huge contamination from low momentum tails of more abundant higher h rigidity idit fragments. Need additional purification of secondary beam!

RF-kicker The RFFS provides purification of

selection ~ 16 m RF kicker Quadrupoles π cell

of PAC, Albuquerque, NM, to be published

17 RF-kicker The RFFS provides purification of neutron deficient beams by time-of-flight selection ~ 16 m RF kicker Quadrupoles π cell Quadrupoles Matching Cell π/2 cell π cel Quadrupoles Selection slits Collimation Experiment M. Doleans et al., Status Report on the NSCL RF Fragment Separator Proc. of PAC, Albuquerque, NM, to be published (2007) 1.5m long RF cavity, Vmax=100kV Beam Rejection factor of > 200 for 100 Sn First experimental campaign in Fall 2008

18 RF-kicker RF Fragment Separator NSCL Beta Counting Station (Mantica et al.) With SeGA -detectors - + The RFFS applies a uniform RF electric field at the cyclotron frequency transverse to the direction of the beam. The various species in the beam cocktail arrive with different RF phases and experience different transverse deflections. This effectively results in a velocity-dependent selection of fragments. Contaminants are eliminated by a set of vertical slits

19 RF-kicker RF Fragment Separator NSCL Beta Counting Station (Mantica et al.) With SeGA -detectors

20 RF-kicker RF Fragment Separator NSCL Beta Counting Station (Mantica et al.) With SeGA -detectors - +

21 RF-kicker RF Fragment Separator NSCL Beta Counting Station (Mantica et al.) With SeGA -detectors

22 RF-kicker RF Fragment Separator NSCL Beta Counting Station (Mantica et al.) With SeGA -detectors - +

23 RF-kicker RF Fragment Separator NSCL Beta Counting Station (Mantica et al.) With SeGA -detectors

24 RF-kicker RF Fragment Separator NSCL Beta Counting Station (Mantica et al.) With SeGA -detectors - + Purification factor = 200

Velocity dependent selection of fragments Energy loss (a a.u.) Energy loss (a a.u.) Time of flight (a.u.) Time of flight (a.u.) Vertica al position (mm) Vertica al position (mm) Time of flight (a.u.) The phase of the RFFS is adjusted to eliminate the most intense contaminants.

25 Velocity dependent selection of fragments Energy loss (a a.u.) Energy loss (a a.u.) Time of flight (a.u.) Time of flight (a.u.) Vertica al position (mm) Vertica al position (mm) Time of flight (a.u.) The phase of the RFFS is adjusted to eliminate the most intense contaminants. Time of flight (a.u.) Weaker contaminants with a 2π phase difference with respect to the fragments of interest will not be removed.

26 Pre-FRIB equipment Adapted from C.K. lbke, NSCL Users meeting 2009

27 FRIB: Facility for Rare Isotope Beams Fragmentation of fast heavy-ion beams combined with gas stopping and reacceleration 200 MeV/u, 400 kw superconducting heavy-ion linac A potential layout for FRIB utilizing i current NSCL facilities MSU and NSCL were chosen as the site for FRIB on 12/11/08.

28 NSCL website: p// / Nuclear Astro group at NSCL:

THE DESIGN AND COMMISSIONING OF THE ACCELERATOR SYSTEM OF THE RARE ISOTOPE REACCELERATOR ReA3 AT MICHIGAN STATE UNIVERSITY*

THE DESIGN AND COMMISSIONING OF THE ACCELERATOR SYSTEM OF THE RARE ISOTOPE REACCELERATOR ReA3 AT MICHIGAN STATE UNIVERSITY* X. Wu#, B. Arend, C. Compton, A. Facco, M. Johnson, D. Lawton, D. Leitner, F.