High-speed streak camera

Jones assumed. It has, in fact, been shown experimentally by Herzberg et al (Ref 2, p 119) that the detonation wave fronts are curved and that the curvature increases as the charge diameter is reduced. A simple method by which this,curvature can be illustrated is provided by the use of a high-speed Streak Camera (same as "Smear Camera" described in Vol 2 of Encycl, p C16-L). 

Detonation, Lateral Shock Pressure Measurements at an Explosive Column. A high speed streak camera technique used for these measurements is described by L.D. Sadwin ... 

Figures 7.12 and 7.13 show the experimental set-up for using a high-speed streak camera or a fast photodiode/osciiioscope for the determination of the detonation velocity.

The continuous viewing of the flame front that travels through the sample can be carried out by an optical technique using high-speed streak cameras. In order to apply such a method for the determination of the combustion chamber with a window made of optically transparent and mechanically resistant material. Through such materials, the combustion process may be recorded by a high-speed streak camera. 

The detonation wave s arrival at the optical fibre, i.e., the light signal accompanying the detonation process, can be either recorded by the optical technique using a high-speed streak camera, or it can be transformed into an electric signal that may be recorded by a fast-storage oscilloscope or a multichannel analyser. 

A high-speed streak camera is used for viewing the cylinder expansion. It records the position of points Q and P at times h and h. Their starting positions at the cylinder wall before the expansion are at the points Q and P. After ti and t2 periods, the detonation wave front occupies new positions Dti and Dt2. In fact, both points P and Q have already begun to expand before being recorded by the streak camera. Thus, the time of particle motion, assigned as r, is greater than the time t, which is measured by the camera r> f). 

Visualization of the process of deformation of porous material was effected by means of a pulsed light source (location 7), an IAB-451 shadow instrument, and a high-speed streak camera (HSSC) operating as a slit sweep. The pressure ratio of the incident shock wave in experiments varied between 1,4-4. 

In the optical method, a high-speed streak camera is used to follow the flame front at about 10 million frames/s, with exposures of as httle as 0.01 ps. 

Y. Tsuchiya, H. Suzuki, M. Koishi, K. Kinoshita, T. Nakamura, Infrared sensitive universal streak camera for use in 1.0 to 1.6 micron wavelength region, in High Speed Photography, Videography, and Photonics III, Proc. SPIE 569, 181-188 (1985). 

Booster was used to initiate the expl at one end. The radial motion of the cylinder wall was measured in a plane perpendicular to the cylinder axis 7 inches from the booster end, A streak camera recorded the motion, using conventional shadowgraph technique (See under CAMERAS, HIGH-SPEED PHOTOGRAPHIC in Vol 2 of Encycl, p CI3-L). In addn, the deton velocity of the expl was measured by placing pin switches 9-i° apart on the surface of the cylinder, as described, for example, by Cook (Ref 2, p 29). The streak camera record was read on a precision comparator which punched out the data directly on IBM cards. A computer code con-... 

The format or film size, shape and dimension, runs the full range of photographic recording. Early streak cameras consisted of a large strip of film wrapped around a drum electrically driven to rotate at a high speed. (See diagram taken from Ref 26)... 

A somewhat unusual approach is encountered when high-speed motion picture cameras of the Hycam type are used as a streak camera. This is accomplished by filming through the camera s viewfinder which bypasses the prism system that normally cuts up the scene into frames or pictures. After nearly one-fourth of the film has run through the camera the voltage-controlled rate of film travel is reasonably steady and can be used for velocity measurements. 

Prior to the advent of powerful lasers, high-speed flash techniques were employed as light sources in time-resolved studies. Research was focused mainly on luminescence studies, aimed at determining fluorescence and phosphorescence Hfetimes. In this connection, the development and successful apphcation of sophisticated methods such as the single-photon time-correlation method and high-speed photography methods (streak camera) are worthy of note. Detailed technical information on these topics is available in a book by Rabek [69]. 

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