HPLUM 17 December 2003 Prof Ian Williams Dr B. Srigengan Mr M. Suresh Mr Jarlath McKenna Prof Roy Newell Dr Will Bryan Mrs Sarah Watson Miss Elizabeth English Dr John Collier Dr Andrew Langley Dr Edwin Divall Dr Chris Hooker
Ti: Sapphire at 790 nm (1.6 eV) Chirped Pulse Amplification Terawatt (10 12 W) Lasers ASTRA ~20 mJ in ~50 fs in TA1 High field physics ~ Wcm -2 1 au = 3 x Wcm -2 Repetition rate 10 Hz
Top plate Drift tube Detector housing Bottom plate Gas-line TOFMS ION BEAM
Potential range ( x ) x0x0 Atomic Potential well V 0 ( x ) Potential well Electric field e-e- e-e- Keldysh Parameter, Ponderomotive Potential, U P I in Wcm -2 & in m
CORE Xe + Linearly Polarized Field 2
Circularly Polarized Field Xe + CORE
Xe 4+ Xe 3+ Xe 2+ ZZ Volume Effects & ISZ-Scanning
Z-scan results from Xe neutral target Time of Flight (sec) Z Position (arb.) Signal (arb.) Typical time-of-flight spectra (z=0mm) Xe 8+ Xe + Xe 2+ Xe 6+ Xe 7+ Xe 5+ Xe 3+ Xe 4+ Xe + Xe 2+ Xe 3+ Xe 4+ Xe 5+ Xe 6+ Xe 7+ Xe Xe Xe Xe 2 +
Xe + Xe 2+ Xe 3+ Xe 4+ Xe 5+ Xe 6+ Xe 7+ Xe 8+ Total Green-Linear-1.3I o Blue- Circular- I O
= 0.5 where n* - effective principal quantum no. Z – charge state of residue ion – E-field
Black - Linear-1.3I o Blue- Circular I o Z-Scan Result of Ne 2+ from Ne
Comparison…. ratioratio ratioratio Ion YieldIon Yield Ion YieldIon Yield Ne Xe Ne Ratio between double and single ionization of Ne and Xe Becker and Faisal J Phys B 32 (1999) L335 t Single and double ionization of Ne and Xe
Metastable population Xe+ 1.2%
Electronic states of Xe + 5s 2 5p eV 2 P 0 3/2, 1/2 4 D 7/2 3 G 0 4, 5 5D045D04 3F043F04 4 F 9/2, 7/2 2 F 7/2 1G041G04 4 S 0 3/2 3 P 2, 1, eV 14.26eV 0.00eV 16.43eV 21.22eV 0.00eV 13.83eV 15.51eV 16.40eV 32.14eV 5s 2 5p 4 5s 2 5p 3 Xe + Xe 2+ Xe 3+
Metastable population Xe %
Xe + Xe 2+ Xe 3+ Xe 4+ Xe 5+ Xe 6+ Xe 7+ Xe 8+ Total Green-Linear-1.3I o Blue- Circular- I O
Metastable population Xe %
Metastable population Xe+ 1.2%
No Significant NS Ionization in Ne 2+