1. Laser Spectroscopy with the Leuven gas cell-based Laser Ion Source @ LISOL Workshop and Users meeting 2011 5-7 December 2011, CERN Rafael Ferrer OUTLINE Production of exotic beams with RILIS @ LISOL In-Gas Cell Laser Spectroscopy Progress toward a full implementation of In-Jet Laser Spectroscopy

2. SELECTIVE (element and isomer) & EFFICIENT PRODUCTION OF RARE ISOTOPE BEAMS  Hot Cavity - No refractory elements - T 1/2 element dependent - Sensitivity 1 ion/s ( 182 Pb) - Resol~ 4 GHz ( 59 Cu) (Doppler) - Produced Ion beams ~30 elements  Gas Cell - All elements available - T 1/2 cell evacuation time - Sensitivity < 1 ion/s ( 97 Ag) - Resol. ~ 3 GHz ( 59 Cu) (Pressure) - Produced Ion beams ~15 elements V.N. Fedoseev et al., NIM B266 (2008) 4378Yu. Kudryavtsev et al., NIM B267 (2009) 2908 IN-SOURCE ATOMIC SPECTROSCOPY Resonance Ionization Laser Ion Source: RILIS R. Ferrer - ISOLDE WORKSHOP ’11 - G. D. Alkhazov et al., NIM B69 (1992) 517 U. Koester et al., Nucl. Phys. A 701 (2002) 441c

3. R. Ferrer - ISOLDE WORKSHOP ’11 - PRL 81 (1998) 03100, PRC 64 (2001) 054308 PRC 74 (2006) 054309, PRC 78 (2008) 041307(R) PRC 79 (2009) 044309, PRC 79 (2009) 044325 Proton-induced fission of 238 U: Fe,Co,Ni,Cu Light Ion-induced fusion evaporation reactions: Co,Ni,Mn,Cr,V,Cu PRC 59 (1999) 2416 PRL 103 (2009) 102501 PRC 81 (2010) 014314 Stopping of 185 MeV stable Ni beam Characterization of gas cell NIM B 187 (2002) 535; NIM B 226 (2004) 401 Sp. fission of 252 Cf: Rh,Ru,Mo,Pd NIM B 266 (2008) 4368 Heavy Ion-induced fusion evaporation reactions: Rh,Ru,Ti,Sn,In,Ag,Ac EPJ A 21 (2004)243  In-source laser spectroscopy at LISOL Yu. Kudryavtev et al., NIM B 267 (2009) 2908 Implementation of ‘Dual Chamber’ gas cell improves ionization efficiency and selectivity LISOL Beams since 1994

4. Dual Chamber Gas Cell Separation of stopping and laser ionization volumes improves: Laser ionization efficiency for high cyclotron beam current Ion selectivity Laser Ionization chamber Laser beams Longitudinal Laser beams Transverse SPIG Ar/He from gas purifier Ion Collector Ionization chamber Stopping chamber Ø 4 cm Filament Beam from Cyclotron Ion collector 500 mbar Exit hole Ø 0.5 – 1 mm Ø 1 cm In-gas-cell spectroscopy of neutron deficient Cu isotopes T. E. Cocolios et al., PRL 103, 102501 (2009) T. E. Cocolios et al., PRC 81, 014314 (2010) Similar measurements near N=Z line around A=100 Selectivity: [Laser(on)/Laser(off)] Ion Collector OFF = 450 Ion Collector ON = 2200 Production of 94 Rh R. Ferrer - ISOLDE WORKSHOP ’11 -

5. 101 Ag 99 Ag 97 Ag R. Ferrer - ISOLDE WORKSHOP ’11 - In-Gas-Cell Laser Spectroscopy of Ag Iain Darby Phys. Lett. B (in preparation) N=50 U. Dinger et al., Nucl. Phys. A 503 (1989) 331 D. Vandeplassche et al., Hyperfine Interact. 22 (1985) 483 92 Mo( 14 N – 130 MeV,2pxn) 104−x Ag 64,nat Zn( 36 Ar – 125 MeV,pxn) 101−97 Ag Derived experimental proton g-factors Open circle calculated value assuming I=7/2+

6. R. Ferrer - ISOLDE WORKSHOP ’11 - Attempt at Laser Spectroscopy of Sn Shift = -150(10) MHz/mbar Broadening=210(25) MHz/mbar Shift = -4.0(0.3) MHz/mbar Broadening=32(4) MHz/mbar Strong -dependence of Sn on pressure No possibility for HFS measurements (FWHM~20GHz)   1P1 1P1 3P0 3P0 continuum λ 1 =254.7 nm λ 2 =454.9 nm IP 59232.69 cm -1 39257.1 cm -1 Aut. state 92 Mo( 16 O-100 MeV,2-3n) 105,106 Sn 120 Sn argon

7. R. Ferrer - ISOLDE WORKSHOP ’11 - Broadband Spectroscopy on Ac 197 Au( 20 Ne-145 MeV,4-5n) 212,213 Ac Cross section 2.3 mb for 212,213 Ac I.P. 43398 cm -1 2 D 3/2 4 P 5/2 418.312 nm 439.21 nm Ac g.s. continuum 23898.86 cm -1 46660.6 cm -1 FWHM= 24 GHz Counts on SEM (arb. u.) FWHM= 81 GHz 1 ST Step2 nd Step Ref. Cell @LARISSA 227 Ac 212 Ac http://www.gsi.de/forschung/ap/projects/laser/survey.html Wavenumbers - 23898.93 (cm -1 ) Alpha counts in 300 s FULL POWER FWHM= 86 GHz POWER ATTEN. FWHM= 32 GHz Wavenumbers – 46660.65 (cm -1 ) FULL POWER FWHM= 170 GHz Gas Cell @LISOL 212 Ac

8. R. Ferrer - ISOLDE WORKSHOP ’11 - In-Jet Laser Spectroscopy Increase Resolution and Sensitivity - Ionization in cold jet expanding out of the gas cell T. Sonoda et al. NIM B267 (2009) 2918 nat Ni FWHM= ~ 2 GHz SPIG 58 Ni Ar 500 mbar Gas cell 58 Ni FWHM=6.5 GHz Ref. Cell 43089.2 43089.6 43090.0 Wavenumber [cm -1 ] Requirements to obtain full benefits : K. Blaum et al., NIM B204 (2003) 331 Ionization in LIST mode - Low density and low temperature in jet reduce significantly Doppler and pressure broadening - Improve time and spatial overlap of laser beams with atoms Demonstrated proof of principle @ LISOL

9. Improving Time Overlap R. Ferrer - ISOLDE WORKSHOP ’11 - - Performance comparison between high repetition Ti:sa lasers and LISOL dye lasers - Comparable results for in-gas-cell ionization - A factor of 60 reduction between in-gas- cell and in-jet ionization for Ti:sa lasers (700 reduction for dye lasers) - HFS of stable 63 Cu in the SPIG limited by laser bandwidth R. F., V. Sonnenschein et al, NIM B in preparation Test of a high pulse repetition rate laser system (Uni-Mainz & GANIL)

10. Improving Spatial Overlap R. Ferrer - ISOLDE WORKSHOP ’11 - 90 o -bent RFQ pumping barrier Extraction RFQ Acceleration region Gas Cell Implementation of de Laval nozzle and bent RFQ - SIMION simulations of new segmented RFQ ion guide : Transmission vs. p, RF amp, DC gradient M. Reponen et al., NIM A 635 (2011) 24 - Test de Laval nozzle and new RFQ @LISOL RFQ Prototype Final measurements @ S 3 (SPIRAL2): Leuven gas cell will couple fragment separator with HRS Awarded ERC Advanced Grant: new lab in K.U. Leuven for Heavy Element Laser Ionization Spectroscopy (HELIOS)

11. R. Ferrer - ISOLDE WORKSHOP ’11 - Single Mode Selection in Dye Laser by a Thick Etalon Study of typical LISOL narrow-band pulse using FP interferometer - Radial profile of interference ring shows four oscillation modes - Separation between modes is 400 MHz  mode FWHM= 150MHz Laser bandwidth ~1.4 GHz (SHG) Implementation of a thicker etalon (14 mm air spaced) allows selection of a single mode  Elimination of mode competition

12. R. Ferrer - ISOLDE WORKSHOP ’11 - 450 MHz 65 Cu 63 Cu A B Ref. Cell Spectrum of the low energy HFS components of the 244 nm line in 63,65 Cu Bandwidth of 450 MHz without minimizing power nor Doppler broadening

13. R. Ferrer - ISOLDE WORKSHOP ’11 - Amplification of CW Single Mode Diode Laser in Pulsed Dye Amplifier Excimer XeCl Laser Dye Amplifier Tunable cw Diode Laser (Toptica) SHG KDP Amp. I Amp. II Towards Ref. Cell 327.49 nm 654.98 nm

14. R. Ferrer - ISOLDE WORKSHOP ’11 - Spectrum of the high energy HFS components of the 327 nm line in 63,65 Cu New ionization scheme required to meet tuneability of diode laser 65 Cu 63 Cu 63,65 Cu C D D+C 150 MHz Estimated 90 MHz Fourier-limited (5ns) laser bandwidth is affected by residual Doppler broadening resulting in a signal linewidth of 150 MHz Ref. Cell

15. Acknowledgments LISOL team: R.F, L. Ghys, M. Huyse, Yu. Kudryavtsev, D. Pauwels, D. Radulov, L. Rens, P. Van den Bergh, C. Van Beveren, and P. Van Duppen LISOL Alumni: T. Cocolios, I.G. Darby, T. Sonoda Collaborators: University of Mainz A. Hakimi, T. Kron, S. Raeder, S. Richter, J. Rossnagel, K. Wendt JYFL University of Jyväskylä I. Moore, M. Reponen, V. Sonnenschein GANIL-SPIRAL2 B. Bastin, S. Franchoo, N. Lecesne, B. Osmond, H. Savajols, J. C. Thomas JINR-Dubna S. Zemlyanoy R. Ferrer - ISOLDE WORKSHOP ’11 -