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HiCATT

Intensified Imaging for Combustion Research

Researchers around the world are using the HiCATT in their combustion studies. The light intensity of flames is not very high, and very short exposure times are needed to see any details. The images below show three recordings of a blue gas flame: image A is a regular recording of a blue gas flame. It shows the general shape of the flame, but the details are lost due to the long exposure time.

Image B was recorded with a high-speed camera at 1000 fps with 1 millisecond exposure time. This image shows some of the fine details of the flame shape, but it is a little dim and blurry. The high-speed camera does a decent job at preventing motion blur by having a short exposure time. But because of this short exposure time, the camera can't collect enough light to capture a detailed image.

Image C shows what a flame looks like when using a 15 microsecond exposure time. To achieve such a short exposure time but retain image detail, we used the fast electro-optical shutter function of the image intensifier. This technique is called gating, and it allows for ultra-short exposure times. During this short exposure time, the image intensifier boosts the intensity of the incoming light to retain image detail.

This unique imaging technology enables experimental investigation of combustion and flame structure. For more information about applications of image intensifier gating for combustion research please have a look at these HiCATT user publications:

 

Baptiste Déjean, Pierre Berthoumieu and Pierre Gajan, Experimental study on the influence of liquid and air boundary conditions on a planar air-blasted liquid sheet, Part II: prefilming zone length in the International Journal of Multiphase Flow

 

Shigeru Tachibana, Kinya Saito, Takeshi Yamamoto, Mitsumasa Makida, Tomoaki Kitano and Ryoichi Kurose, Experimental and numerical investigation of thermo-acoustic instability in a liquid-fuel aero-engine combustor at elevated pressure: Validity of large-eddy simulation of spray combustion in Combustion and Flame

 

Min Jung Lee, Moon Soo Cho and Nam Il Kim, Characteristics of opposed flow partially premixed flames in mesoscale channels at low strain rates in Proceedings of the Combustion Institute

 

For a full overview of HiCATT user publications, please visit our HiCATT User Publications page.

No More Motion Blur

High-speed cameras are great for recording highly dynamic events. Experts in ballistics research, combustion analysis and in-vivo imaging require fast cameras for their work. The high frame rates give them unprecedented insight into what happens in the blink of an eye.

But even the best high-speed cameras have their limits. In some situations even the fastest cameras are not fast enough. Objects move too fast or emit too little light to produce a crisp image. The result is a dim or blurry picture that hardly contains any useful information.

These situations call for a high-tech solution that offers extremely short exposure times or extreme light sensitivity. With an image intensifier you can use its gating feature to achieve exposure times down to 3 ns, completely eliminating motion blur. With such a short exposure time, even very fast objects can be imaged clearly. And because the image intensifier amplifies the recorded light, you don't have to worry about underexposure.

The Lambert Instruments HiCATT upgrades your high-speed camera to the next level of performance. It is compatible with any high-speed camera and all popular lens mounts. Its image intensifier component is carefully selected to match your desired frame rate and light sensitivity. Our custom software lets you control the exposure time and the gain of the HiCATT to find the right settings for your application.

Engineers and researchers around the world use the HiCATT to study bullet trajectories, combustion processes in fuel injection engines, and voltage sensitive dyes in living tissue. Find out more about HiCATT applications and technical information.

How To Freeze A Flame: Watching Combustion in Super-Slow Motion

Some things happen too fast for the human eye to see. The blades of a spinning fan, for example, look like a blur to us. They move too quickly for our eyes to see them the way we do when the fan is off.

The same thing happens when we look at a flame. It may look like a slowly waving sheet of warm light to the human eye, but in reality it is a swirling chemical process that changes faster than we can see. Even digital cameras have a hard time recording combustion processes.

The dynamic nature of the flames requires a high-speed camera that can record thousands of images per second with each one of those images recorded in a fraction of a second. But while images can be captured during those brief periods, a regular high-speed camera can’t capture enough light to produce a clear image. It’s a challenge that combustion researchers have struggled with for a long time.

Combustion cycle of a fuel injection engine.

Combustion cycle of a fuel injection engine.

The solution is a camera that is both fast and extremely sensitive to light. We combined these advanced features into one system with the HiCAM, a high-speed camera with an unparalleled light sensitivity. It records clear images in an instant and produces super-slow motion videos that accurately show the behavior of a flame. With the HiCAM, researchers are now able to quantitatively study combustion processes in combustion burners and in fuel injection engines.

Gain Control for Automation Systems

Introducing a new control unit for intensifier attachments: The gain control unit for automated systems enables full control over the gain and anode current limit of the image intensifier. Communication over TTL and analog signals provides precise timing and ensures straightforward integration of an intensifier into your imaging system. And with its built-in protection features, the control unit helps to protect the image intensifier from overexposure.

The gain control unit for automation systems is now available with our HiCATT and TRiCATT intensified camera attachments.

Mechanical shutter for HiCAM and HiCATT

Being very sensitive tools for ultra high speed imaging the HiCATT and HiCAM are often exposed to high energy radiation. Applications like combustion experiments or UV-spectroscopy in a synchrotron beamline are good examples for situations where the photocathode can be prone to harmful scattered or direct incident light. Although this is fine during the actual measurements, extended exposure to stray light or laser bundles during alignment and other activities may damage the photocathode.

To avoid fiddling with lenscaps between measurements we have added a mechanical shutter to our intensified high speed product line. The shutter is encased in a aluminum housing with a standard F-mount input that replaces the original F-mount adapter of the HiCATT or HiCAM. The back focal distance of the F-mount input is unchanged so any F-mount objective can be used. The shutter comes with a power supply and a remote shutter controller with a timer. The timer can be used to automatically close shutter after a predetermined time. The remote has a stylish and ergonomic design and a large LCD screen. The shutter can also be controlled by a external TTL signal. When purchased together with one of our digital interfaces (s, d or p option) the shutter is controlled by the software of the digital interface.