Laser activities at University of Pavia in support to SPES project Daniele Scarpa

The target ion source complex Target complex Ion Source complex

Surface Ion source 12 HHe LiBeBCNOFNe NaMgAlSiPSClAr KCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKr RbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXe CsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRn FrRaAcRfDbSgBhHsMt 8 Elements with bad volatility (NOT EXTRACTED) Surface Ionization Method Laser beam Laser with SIS Photo Ionization Method Ionization Method Plasma Ionization Method IONIZATION methods for SPES n-rich RIB’s (3 methods, 2 Ion sources) Main fission (p-> 238 U) fragments Plasma Ion source

The target ion source complex Target complex Ion Source complex

Laser activities at University of Pavia in support to SPES project Outline: Pavia activities LNL activities Conclusion Remarks

Laser activities at University of Pavia in support to SPES project Pavia Lab Activities Change Laser System Setup Laser alignment and characterization (Hollow Cathode Lamp (HCL)) Time of Flight (TOF)

Pavia Lab setup ND:Yag Pump Laser 10 Hz rep rate Dye Laser 3λ ionization scheme: test on HCL find & test best ionization path with OGE signal test on ionization chamber measure ionization efficiency with TOF Dye Laser or TOFTOF Laser activities at University of Pavia in support to SPES project

Work on Nd:YAG and dye laser Beam Quality Optimization Moreover: - Power characterization - Align system in order to pump Dye Laser -Changing dye optics -Dye laser optimization -Laser Dye tests with Etalon and SHG crystal

Testing Laser Ionization: Hollow Cathode Lamp Optogalvanic effects are changes in the conductance of a gas discharge caused by absorption of light via a bound-ionization states transition in an atom or molecule in the discharge. Good & Simple Atoms Reservoir Very Suitable for Spectroscopic Investigations Laser activities at University of Pavia in support to SPES project

Slow optogalvanic signal System goes to the new electronic states equilibrium after some microsec sharing the energy delivered by laser resonant photons E1E1 E0E0 E2E2 Φ Laser activities at University of Pavia in support to SPES project

System releases electrons immediately due to the direct photoionization E1E1 E0E0 E2E2 Φ Fast optogalvanic signal Laser activities at University of Pavia in support to SPES project

Neodymium selective laser ionization Three steps, two colors ionization path Laser activities at University of Pavia in support to SPES project 5900 A 5970 A 5888 A Second step scanning Typical second transition linewidth Signal vs Laser power

Laser activities at University of Pavia in support to SPES project Laser ionization (Bandwidth) 0 eV ≈6 eV Typical absorption linewidth: 0,01Å Laser linewidth : Selectivity Power “exploitment” Φ

Aluminum selective laser ionization Two step, one color ionization path: Al [ ; e−] Al+ λ λ First step: Resonant λ =308,216 nm Second step: Non – resonant towards continuum same wavelength λ =308,216 nm Laser activities at University of Pavia in support to SPES project Typical transition linewidth

TOF preliminary tests Laser activities at University of Pavia in support to SPES project Gate pulse 112 Cd 118 Sn 207 Pb

Laser activities at University of Pavia in support to SPES project LNL Laser Lab Activities Collateral activities.. Laser Ionization of Aluminum in SPES hot cavity

Front End Alignment [1] Barbui et all. Nuclear Instruments and Methods in Physics Research B 266 (2008) 4289 – 4293 Laser line as reference for all the system Laser activities at University of Pavia in support to SPES project

Temperature characterization with fiber optic instrument Laser activities at University of Pavia in support to SPES project Possible future online temperature control with fiber optic pirometer outside hard radiation area

Laser activities at University of Pavia in support to SPES project International collaboration

Why Aluminum [1] Barbui et all. Nuclear Instruments and Methods in Physics Research B 266 (2008) 4289 – 4293 SPES has developed a SiC target tested at HRIBF in Oak Ridge Aluminum comes from (Si,p) nuclear interaction Laser activities at University of Pavia in support to SPES project

Laser beam delivery Laser activities at University of Pavia in support to SPES project Laser beam shape study in order to focalize into hot cavity 3 mm diameter 6 m far away Laser safety study with Jesus Vasquez

Ionization first results (Faraday Cup Current) Laser off Laser On Laser activities at University of Pavia in support to SPES project

Ionization results Faraday Cup several pulse energy and frequency 20 Hz ; 12 mJ per pulse 20 Hz ; 20 mJ per pulse Laser activities at University of Pavia in support to SPES project 50 Hz 25 Hz 12 Hz off

Conclusions: Laser activities at University of Pavia in support to SPES project Pavia: New laboratory setup to use Nd:YAG + 3 dye laser Nd:YAG characterization and optimization Dye laser change optics for Nd:YAG Dye laser characterization and optimization Spectroscopic analysis of Nd, Al and other elements TOF functional tests Other TOF test scheduled Selective Laser ionization + TOF LNL: Front end alignment & laser safety First measurements with laser on Aluminum Fiber optic temperature reading Integral current measurements & data analysis Measure with Wien filter

Remarks: Laser activities at University of Pavia in support to SPES project Complex laser system => more study, people and training Rapid laser technologic evolution: => Keeping update and informed => Buy -1,5 ÷ 2 Y not before Some parameter has to be well defined: => choosing system properties and cost