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Multiple Charged Ions Production From Xe + & Xe 2+ In Intense Laser Field. 1 Laser Background. 2 Apparatus Overview. 3 Ion Beam Properties. A Energy Spread B Spatial Spread. 4 Xe + & Xe 2+ In Laser. 5 Z-Scan of Laser Focus. BY M.SURESH. 6 Summary. Femtosecond Lasers.
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Multiple Charged Ions Production From Xe+ & Xe2+ In Intense Laser Field 1 Laser Background 2 Apparatus Overview 3 Ion Beam Properties A Energy Spread B Spatial Spread 4 Xe+ & Xe2+ In Laser 5 Z-Scan of Laser Focus BY M.SURESH 6 Summary
Femtosecond Lasers • Ti: Sapphire at 800 nm (1.6 eV) • Chirped Pulse Amplification • Terrawatt (1012 W) Lasers ASTRA ~10 mJ in ~10 fs • High field physics > 1016 Wcm-2 1 au = 3 x 1016 Wcm-2 • Repetition rate 10 Hz
Entrance Window Exit Window Shadow Laser Beam Two Wire Crosses Laser Alignment
Xe+ Xe2+ Voltage (V) Voltage (V) Analyzer Plate Scan for Multiply Charged Ions of and Time of Flight Time of Flight
ION BEAM CHARACTERIZATION Spatial SpreadMeasurement 1 mm Aperture 0.5 mm Aperture 0.13 mm Slit
Spatial Spread of He+ and Ar+ at Different Ion Beam Energies Spatial Spread Depends On Energy And Mass Of The Beam
Spatial Spread Scan of He+ Ion Beam Selected by 1mm & 2mm Apertures 2 mm Aperture Ion beam Current (nA) 1 mm Aperture Slit Position (mm) • Current Decreases From 300nA To 120nA
Spatial Spread of He+ and Ar+ (3keV) With 1mm & 2mm Apertures • Spatial Spread Depends on Aperture Size
Spatial Spread of He+ Ion Beam at Different Focusing Conditions
2KeV Energy Spread (eV) 1KeV Discharge Voltage (V) Energy Spread of 1keV and 2keV Ar+ - 2 mm Aperture Nergy Spread(eV)
1.1E-8 1.0E-8 9.0E-9 8.0E-9 7.0E-9 6.0E-9 6.0E-9 Signal 5.0E-9 5.0E-9 4.0E-9 4.0E-9 3.0E-9 3.0E-9 2.0E-9 2.0E-9 1.0E-9 1.0E-9 0.0E+0 0.0E+0 -1.0E-9 -1.0E-9 0.0000 5.0000 10.0000 15.0000 20.0000 0.0000 5.0000 10.0000 15.0000 20.0000 25.0000 Z-Position (mm) Z-scan of Xe3+ from Xe2+ Z -scan of Xe4+ from Xe2+
0.0E+0 2.5E-9 -2.0E-10 2.3E-9 2.0E-9 -4.0E-10 1.7E-9 1.5E-9 Signal -6.0E-10 1.3E-9 1.0E-9 -8.0E-10 7.5E-10 5.0E-10 -1.0E-9 2.5E-10 -1.2E-9 0.0E+0 -2.5E-10 -1.4E-9 -5.0E-10 0.0000 1.0000 2.0000 3.0000 4.0000 5.0000 6.0000 0.0000 5.0000 10.0000 15.0000 20.0000 25.0000 Z-Position (mm) Z-scan of Xe6+ from Xe2+ Z-scan of Xe7+ from Xe2+
Summary Less Than 2% Energy spread 0.34mm Spatial Spread First experimental results onXe2+ in intense laser field Up to Xe7+ from both Xe+ and Xe2+