Evaluation of the irising effect of a slow-gating ICCD on laser-induced incandescence measurements of soot.

Journal Article · Wed Oct 01 04:00:00 EDT 2008 · Proposed for publication in Review of Scientific Instruments.

OSTI ID:951527

Williams, Timothy C; Shaddix, Christopher R

Intensified charge-coupled devices (ICCDs) are used extensively in many scientific and engineering environments to image weak or temporally short optical events. To optimize the quantum efficiency of light collection, many of these devices are chosen to have characteristic intensifier gate times that are relatively slow, on the order of tens of nanoseconds. For many measurements associated with nanosecond laser sources, such as scattering-based diagnostics and most laser-induced fluorescence applications, the signals rise and decay sufficiently fast during and after the laser pulse that the intensifier gate may be set to close after the cessation of the signal and still effectively reject interferences associated with longer time scales. However, the relatively long time scale and complex temporal response of laser-induced incandescence (LII) of nanometer-sized particles (such as soot) offer a difficult challenge to the use of slow-gating ICCDs for quantitative measurements. In this paper, ultraviolet Rayleigh scattering imaging is used to quantify the irising effect of a slow-gating scientific ICCD camera, and an analysis is conducted of LII image data collected with this camera as a function of intensifier gate width. The results demonstrate that relatively prompt LII detection, generally desirable to minimize the influences of particle size and local gas pressure and temperature on measurements of the soot volume fraction, is strongly influenced by the irising effect of slow-gating ICCDs.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 951527
• Report Number(s): SAND2008-7137J
• Journal Information: Proposed for publication in Review of Scientific Instruments., Journal Name: Proposed for publication in Review of Scientific Instruments.
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CHARGE-COUPLED DEVICES
EVALUATION
FLUORESCENCE
LASERS
PARTICLE SIZE
RAYLEIGH SCATTERING
SOOT
TIME DELAY