science-softCon uv/vis+ photochemistry database;	www.photochemistry; (C) science-softCon 2019

Substance: methyl radical				Other Names: 

Formula: CH3						CAS-No.: 2229-07-4

Study: photoionization cross sections

                
Authors: C.A. Taatjes, D.L. Osborn, T.M. Selby, G. Meloni, H. Fan, S.T. Pratt

Title: Absolute photoionization cross-section of the methyl radical

Journal/Source: J. Phys. Chem. A, 112 (39), 9336-9343, (2009); DOI: 10.1021/jp8022937


Data: 

Energy/Wavelength range: 10.2 eV; 11.0 eV (~ 121.5 nm; 112.7 nm)

Resolution: 

Temperature: 

Temperature dependence: 

Pressure/Concentration: 

Phase:

pH:


Comments: The CH3 photoionization cross-section was determined relative to that of acetone and methyl vinyl ketone at photon 
energies of 10.2 and 11.0 eV. The absolute photoionization cross-section of the methyl radical are: sigma CH3(10.2 eV) = (5.7 ± 0.9) × 10-18 cm2 
and sigma CH3(11.0 eV) = (6.0 ± 2.0) × 10-18 cm2.
The methyl radical photoionization cross-section was also independently measured relative to that of the iodine atom by comparison 
of ionization signals from CH3 and I fragments following 266 nm photolysis of methyl iodide in a molecular-beam ion-imaging apparatus. 
These measurements gave a cross-section of (5.4 ± 2.0) × 10-18 cm2 at 10.460 eV, (5.5 ± 2.0) × 10-18 cm2 at 10.466 eV, and 
(4.9 ± 2.0) × 10-18 cm2 at 10.471 eV. 

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