ATLAS/CARIBU Status Guy Savard Scientific Director of ATLAS Argonne National Laboratory & University of Chicago Workshop on Future GRETINA Science Campaigns Argonne National Laboratory, March 1, 2013

2 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 Existing ATLAS facility  Stable beams at high intensity and energy up to MeV/u  Light in-flight radioactive beams –light beams, no chemical limitations, close to stability, acceptable beam properties  CARIBU beams –heavy n-rich from Cf fission, no chemical limitations, low intensity, ATLAS beam quality, energies up to 15 MeV/u  State-of-the-art instrumentation for Coulomb barrier and low-energy experiments  Operating over 5000 hrs/yr at about 95% efficiency –Users performing experiments at ATLAS: FY10: 390 FY11: 326 FY12: 394 –About 10 Ph.D. theses per year (16 in FY12) Suite of experimental equipment 3 injectors

3 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 Neutron-rich beam source for ATLAS: CARIBU “front end” layout Main components of CARIBU –PRODUCTION: “ion source” is 252 Cf source inside gas catcher Thermalizes fission fragments Extracts all species quickly Forms low emittance beam –SELECTION: Isobar separator Purifies beam –DELIVERY: beamlines and preparation Switchyard Low-energy buncher and beamlines Charge breeder to Increase charge state for post- acceleration Post-accelerator ATLAS and weak-beam diagnostics

4 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 CARIBU gas catcher: transforms fission recoils into a beam with good optical properties  Based on smaller devices developed at ANL –Radioactive recoils stop in sub-ppb level impurity Helium gas – Radioactive ion transport by RF field + DC field + gas flow –Stainless steel and ceramics construction (1.2 m length, 50 cm inner diameter) –Fast and essentially universally applicable –Extraction in 2 RFQ sections with μRFQs for differential pumping He gas DC gradient To acceleration and mass separator RF (cone) RF (body) 252 Cf

5 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 CARIBU building with first experiment (CPT mass spectrometer) April 2011

6 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013  1 Ci 252 Cf source  about 20% of total activity extracted as ions  works for all species  complementary to uranium fission Extracted isotope yield at low energy (50 keV) > than 500 neutron-rich species extracted at > 1/s > 150 whose masses have never been measured

7 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 CPT Measurement campaigns

8 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 Atomic Mass Evaluation comparison Trend: more neutron-rich nuclei are found to be less bound than expected away from stability In Sn Sb Te I Xe Cs Pr Nd Pm Sm Eu Gd Higher N

9 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 CPT Measurement campaigns

10 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 CPT Measurement campaigns Being completed from previous PAC measurements for r-process studies measurements for new isotope discovery Ongoing heavy-peak measurements

11 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 First Coulex with 141 Cs – two goals: 1. Demonstrate feasibility & study backgrounds from stable beam contamination and  decay with 850 MeV beam on Pb; i.e., “unsafe” Coulomb excitation; 4300 part/sec for 14.5 hours run. 2. Measure B(E2) of the 11/2 + state in 141 Cs, via “safe Coulex” at 601 MeV for ~62 hours with ~3360 part/sec. B(E2) = 20(5) W.u., smaller than the 2 + level in 142 Ba (32(1) W.u.), but similar to the value for the 2 + state in 140 Xe (25.6(8) W.u). Figure: Gamma-ray spectra from 601- & 850- MeV 141 Cs with the Coulomb excitation line at keV. S. Zhu et al., to be published First Coulomb excitation measurement with a CARIBU beam

12 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 ATLAS layout with ongoing and planned upgrades CARIBU New in-flight separator (AIRIS) EBIS MHB RFQ new cryomodule cryomodule and rebuncher rearranged High-Intensity ECR New low-energy experimental hall Improved instrumentation 12 Novel design from Accelerator R&D group World record performance

13 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 All PMP milestones have been met, beam tune developed, now operational. ParameterRequired ValueDemonstratedDesign Beam Output Energy~220 keV/u293 keV/u Transmission for any test ion beam with input normalized rms emittance 0.1  -mm-mrad  65% 83% Charge-to-mass ratio of a test ion beamQ/A < 1/51/5.71/7 Duty cycle100% ARRA funded upgrade: New RFQ accelerator section of PII linac

14 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 Installation of cryomodule components (liquid helium manifold, helium and nitrogen plumbing, slow tuners, RF coupler warm windows, temperature sensors,…) and alignment of evacuated cavity-solenoid string is in progress Cryomodule vacuum vessel is ready to receive cavity-solenoid string   Plans for FY2013 1)Complete off-line assembly and cold testing 2)Install into the beam line (Jun.-Sept. 2013) and commission with beam ARRA funded upgrade: Replacement of first booster cryostat module and liquid helium upgrade

15 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013  1 st stage of ARRA funded upgrade –Front end reconfiguration (RFQ, PII cavities rearrangement, electrostatic optics) completed –Commissioning completed Total transmission of 80% demonstrated –New tunes have been developed, ready for operation …. actually running today!!!  2 nd stage of ARRA funded upgrade –Construction of cryostat and cavities completed –Mock up assembly completed, final assembly on-going –Preparation for new cryostat installation and booster rearrangement ongoing –Expecting to shut down ATLAS for installation at the end of May for ~ 4 months –Restart in October, facility operational when GRETINA is ready for operation at ATLAS 15 Summary of ongoing intensity and efficiency upgrade

16 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013  Community plan for GRETINA in coming years: –Complete MSU campaign by July ; –Move to ATLAS and installation; –ATLAS/CARIBU campaign from October 2013 to December –Return to MSU  Preparation for campaign: –Site preparation ongoing for stand-alone operation and operation in front of the FMA; –GRETINA WORKSHOP (March 1-2 at Argonne); Day 1: discuss and exchange information with GRETINA users on the detailed science opportunities at ATLAS. Provide guidance for the coming call for proposals, Day 2: discuss science opportunities and future siting of GRETINA beyond the ATLAS campaign. –Call for proposals including ATLAS/CARIBU beams to GRETINA (early March 2013) –ATLAS/GRETINA PAC (May 2013) –GRETINA installation at ATLAS (July-October 2013) –Completion of ATLAS ARRA funded upgrade and installation of new source at CARIBU (September-October 2013) –Start of GRETINA campaign at ATLAS (October 2013) Preparation for GRETINA campaign at ATLAS

17 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 ATLAS next few years running plan  FY2012 ( hrs): –CARIBU started (1542 hrs)  move to stronger Cf source –ATLAS running (6140 hrs) + modifications to prepare RFQ installation  FY2013 ( hrs): –Fall PAC: accepted experiments for ATLAS and low-energy and reaccelerated CARIBU beams –Fall  RFQ installation  ATLAS running tandem beams, CARIBU running low-energy with “1Ci source” –Winter/Spring: ATLAS + low-energy and reaccelerated CARIBU beams available –Spring PAC: accepting GRETINA experiments + all other ATLAS/CARIBU experiments –Summer  booster reconfiguration  low-energy CARIBU beams, no ATLAS beams, GRETINA arrives  FY2014 ( hrs): –GRETINA + CARIBU/ATLAS beams, low-energy CARIBU beams –Deep-inelastic production along N=126 for CPT/X-array, move tandem out, new CARIBU source  FY2015 ( hrs): –Fall  EBIS installation  Low-energy CARIBU beams, ATLAS beams, GRETINA leaves –Winter/Spring/Summer  AGFA installation, large CARIBU experimental area available, all beams available ( hrs)

18 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 Status  ATLAS is preparing for the GRETINA campaign –ARRA funded upgrade being completed by Oct 2013 –Ongoing preparation for GRETINA In “stand alone” mode on APEX beamline In front of FMA –New stronger 252 Cf source requested for the fall –Running a number of CARIBU reaccelerated beam experiments this spring  Need input from the community –What experiments do you want to be able to do with GRETINA at ATLAS? Are the two locations the right ones? Are they enough? Are they both needed? What auxiliary detectors need to be accommodated? –Should we setup campaigns? –What information do we need to provide to users? –What experiments are best done with GRETINA, what experiments are best done with Digital Gammasphere? –How do we handle the data?

19 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013

20 ATLAS\CARIBU Status Guy Savard, Argonne National Laboratory February 15, 2013 Gammasphere  Digital Gammasphere Gammasphere  World-leading  -spectrometer  100 HPGe Compton suppressed  In front of FMA or in stand-alone mode  Ancillary detectors –CHICO: Coulomb Excitation –HERCULES: Evaporation residues –MicroBall: charged particles –Neutron wall –Rotating target wheel: High intensity –Plungers: Lifetime studies –X-ray counters  ~ 40% of beamtime at ATLAS Digital upgrade  Goal: Increase rates x 4-12  Digitize energy signals  Done … no loss in resolution, X4 gain in countrate capability  Use Gretina digitizers  Digitize BGO shields  Status: Ongoing  Completion: 2013 Digital 40K/s and 1  s shaping is as good as “Old” and 10  s shaping