1. CHICO-II; a 4π heavy-ion detector LLNL-Rochester CHICO2 collaboration LLNL:C-Y. Wu U. Rochester:A.B. Hayes, D. Cline, R. Flight, A. Melchionna, C. Zhou Engineering:D. Swan (Cathodes, GHz amplifiers, transmission lines), R. Fox ( DAQ software) Funding:DOE and NSF GRETINA Meeting, ANL, 1-2 March 2013

2. CHICO-II purpose CHICO-II, is designed to exploit GRETINA and Gammasphere for study of quasi-binary reactions using stable or exotic beams: Coulomb excitation Single and multi-nucleon transfer reactions Deep inelastic reactions Fission CHICO2 is an upgrade of the CHICO detector that has been used with Gammasphere since 1996.

3. Ge detector CHICO Scattering angle: 12   85  (Front Part) 95   168  (Back Part) Azimuthal angle total: 280  of 360  Position resolution:  1  in  and 9.3  in  Solid angle: 69% of 4π Time resolution:  500 ps Mass resolution Δm/m = 5% Q-value resolution: ≤ 20 MeV CHICO * M.W.Simon, D. Cline, C.Y. Wu R.W. Gray, R. Teng. C. Long Nucl. Inst. Meth. A452 (2000) 205 * Work supported by the NSF

6. Doppler-corrected γ-ray spectra 1358 MeV 238 U on 170 Er Raw data Correction for U-like recoils Correction for Er-like recoils C.Y. Wu, D. Cline, et al, Phys. Rev. C61 (2000) 21305(R) CHICO/Gammasphere

7. CHICO2 upgrade Design and fabricate cathodes with high segmentation for both θ and ϕ Fast amplifiers with improved signal to noise and anode energy-loss output signal Replace 17 year-old FERA electronics with modern electronics to facilitate merging with the GRETINA and Gammasphere data acquisition systems. Remove clamp lugs to allow use of CHICO2 with GRETINA. Developed a new clamping method. Major renovation of most of the CHICO detector and ancillary equipment.

8. CHICO2 cathode board

9. Mounting an anode frame in CHICO2

11. CHICO-II specifications Angular coverage: 12 o ≤ θ ≤ 85 o, 95 o ≤ θ ≤ 168 o ; 280 o in φ Angular resolution:Δθ = 1 o, Δφ = 1.4 o Solid angle:69% of 4π Energy-loss output: Improved time, mass and Z resolution Time resolution:Δt ≤ 500ps Mass resolution for kinematic coincidence:Δm/m ≤ 5% Q-value resolution:≤ 20 MeV Gammasphere γ-ray Doppler broadening: 0.8% * GRETINA γ-ray Doppler broadening: 0.2% * * Ignores contribution due to intrinsic resolution etc.

12. SCHEDULE Completed:Implement upgrade of CHICO and test using 252 Cf fission source 9 -10 March: Move CHICO2 equipment (3100lbs) from Rochester to ANL 11 – 17 March: Mechanical installation and vacuum test. 18 – 25 March:Merge the CHICO2 and Gammasphere DAQ systems 2 – 3 April:Stable beam test run 10 – 21 April:Commence CHICO2/Gammasphere research program. Coulex of a 144 Ba beam from CARIBU

13. CHICO2 plus GRETINA operation CHICO2 operation should be fully proven and robust when GRETINA is available. Prior experience using CHICO2 with Digital Gammasphere should facilitate merging the GRETINA and CHICO2 data acquisition systems. GRETINA modules can be used at angles 12 0  θ  168 0 and all ϕ angles except where blocked by the target ladder at (θ, ϕ ) = (90 0,90 0 ) or the alignment lugs at (θ, ϕ ) = (90 0, 0 0 ) and (θ, ϕ ) = (90 0,180 0 ) The GRETINA Ge crystal have an inner radius of 185mm while the cryostat is 178mm which is the radius of CHICO2. Thus it will be desirable to off-set GRETINA relative to CHICO2 by 2mm for clearance. CHICO2 is robust and insensitive to high count rates and high radiation levels.