Requirements for Combustion Kinetics Studies at JLab

Craig A. Taatjes, David L. Osborn, Leonid Sheps

Photon Beam Requirements

• Tunability– Require photon energies from ~ 6 eV to ~16 eV, depending on

the specific target – Continuous tunability is important for species quantification– Piecewise-continuous or partial coverage is less desirable

• Energy bandwidth – Energy bandwidth of 25 meV is sufficient – Probably need to separate fundamental, higher harmonics out

• High average power, low peak intensity– Keep peak intensity less than ~ 500 kW / cm2 – Collimated beam, diameter <~ 2 mm if possible

Requirements for Experimental Hall

• Footprint of reaction chamber– Also need cart with excimer laser– Pumps with exhaust: scroll pumps backing turbos, roots blower

for reactor– Associated computer equipment

• Chemical handling – toxic gases – excimer gases, Cl2, NO2

– toxic liquids delivered from bubblers– flammable gases

• No extraordinary power and water requirements– Water cooling for turbos and excimer– 208 3-phase for excimer ?

Connection to Beamline

Laser cart is 34.5 x 49 inches, 100 inches high

Orthogonal Extraction Time-of-Flight

Coles and Guilhaus, Trends in Analytical Chemistry, 12, 203 (1993).

Sandia OA-TOF

continuous ion optics

differential-pumping wall

orthogonalextractor

Photon and Ion Beam Paths

0.25 inch between repeller and extractor

2 mm apertures in repeller and extractor

~2 mm is maximum useful photon beam diameter (smaller is better for mass resolution)