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Cameras for Electron Microscopy
Princeton Instruments, the leading manufacturer of cooled CCD cameras for scientific applications worldwide, offers a complete line of cameras for electron microscopy. We provide a wide range of CCDs, state of the art scintillators, and high performance camera electronics, as well as computer interfaces and software to match diverse requirements.
Princeton Instruments, Inc., in collaboration with Ernest F. Fullam, Inc., has developed a cooled CCD camera system for digital imaging on transmission electron microscopes (TEM). This high resolution, high contrast, and highly sensitive cooled CCD camera system can increase the productivity of a TEM laboratory and dramatically reduce its darkroom costs. The system mounts on the 35 mm port located just above the viewing chamber on most TEMs and does not require any modification to the TEM. It consists of a scintillator assembly, a CCD camera, a controller, and imaging software. The scintillator assembly is mounted on a retractable holder attached to one side of the 35 mm port. It may be retracted away from the electron beam path at any time, without breaking vacuum. This allows you to switch to the image on the viewing screen at any time. The image for the CCD camera is created by a scintillator, either a single YAG crystal or a fine grain phosphor screen. The image is then transmitted through the scintillator onto a CCD camera and then displayed on a computer monitor. The CCD camera is rotatable about the optical axis so the image can be oriented the way you like it, for your presentation.

Princeton Instrument's cooled CCD camera with a TEM adapter manufactured by Ernest F. Fullam, Inc. Since the mounting used by the two scintillators is identical they are easy to interchange, so you can select the best scintillator for your sample. The CCD camera is easily removeable, allowing you to use it for any other digital imaging application in your laboratory.

Special Applications

Optimized Resolution
For both applications, the resolution of the scintillator is optimally matched to the resolution of the CCD. We accomplish this by selecting optimum lens demagnification ratios. We offer CCDs with pixels as small as 6.8 µm x 6.8 µm and CCD arrays with very high spatial resolution, up to 4,000 в 4,000 pixels.

Cameras for Biological and Medical Applications
In biological and medical applications the magnification is typically somewhat lower, flux is higher, and microscope stability is less of an issue. Low contrast in the subject being imaged is a major detection limitation and mostly depends on sample preparation. For these applications, we offer front illuminated CCD cameras with small pixel sizes. Software contrast enhancement can reveal tremendous datail in hardto-image low absorption samples.

Highest Performance Scintillators
For any camera system, Princeton Instruments, Inc. offers two different types of scintillators. Powdered phosphors can be used for maximum light output at low fluxes. Single crystal YAG:Ce scintillators provide higher resolution, uniformity and durability. The flexible mechanical design allows you to change scintillators with ease, so your system can move ahead to the latest in scintillator technology as it is developed.

Cameras for Materials Science Applications
In materials science applications magnifications are typically high, flux is low and exposure times can be limited by the movement of the microscope. For this application we offer front and back illuminated cameras. These camera provide higher sensitivity and a dynamic range of at least four orders of magnitude. Princeton Instruments

Alignment, Focusing, and Precision Image Collection
Early attempts to adapt cooled CCD technology to electron microscopes were limited by slow single speed electronics. This led to the use of a video camera in parallel with a cooled camera, to support alternate sample alignment and precision data colTel: 609-587-9797

An image of a rat hepatoma cell, courtesy of Ms. Neelima Shah, Univ. of Penn. 90


lection. Because both cameras had to reside in a vacuum and be moved in and out of the focal plane for operation, these systems inevitably became mechanically complex and expensive. Princeton Instruments has overcome this problem with superior electronic circuitry and software that supports both fast and slow readouts of a single cooled CCD camera. This more elegant design eliminates the need for complex mechanisms and ensures that the field of view obtained in alignment mode is exactly the field of view seen at higher resolution.

enough signal. Too little gain and you will begin to miss electrons. We offer a variety of CCD arrays and scintillators to provide exactly the gain you need. Princeton Instruments also offers digital image accumulation electronics that can sum up successive frames in real time. This, combined with our high readout speeds, allows signal to be accumulated up to levels far beyond the capacity of any CCD array in a single readout. With this digital image accumulation system, low contrast targets are easily discerned. Targets which vary widely in thickness and thus have very high dynamic range can also be imaged easily. Individual readouts can achieve 16 bits dynamic range. Real time hardware accumulation of digital frames can extend this to 32 bits per pixel. See the description of the Model ST-138 Camera Controller for more detail about this accumulator option.

tal interfaces to all major computer models, including IBM AT compatible PCs, Apple Macintosh and Power Macs, and numerous workstations. We offer both integrated software packages (combining both image acquisition and image processing) and software tools to do your own development. See the description of WinView, IPLab, and other software packages supported by Princeton Instruments for more detail.

Wide Selection of CCD Arrays
As a major manufacturer of cooled CCD cameras, we have optimized designs for over 15 different CCD arrays. This means that we can offer a CCD that most closely fits your technical requirements and budget. We offer high resolution CCD arrays up to 4,000 в 4,000 pixels. For high dynamic range electron diffraction work, we offer antiblooming CCD arrays with up to 1000в protection. For low contrast biological and medical images, we offer CCD arrays with an electron well capacity of up to 500,000 electrons. For very fragile samples, which may get damaged with high flux, we offer back illuminated CCD arrays. Finally, for long exposure times, we offer CCD arrays with the best MPP dark current reduction available. We offer CCD arrays from EEV, Kodak, and SITe. We often test new CCD designs before they are released to the general market, and we have even designed custom CCD arrays for special applications. We can always provide the latest in CCD technology for your demanding application.

Low Noise Electronics
Our CCD electronics offer extremely low noise readout. As a testament to this, our cameras are used by several CCD manufacturers (Kodak, SITe, and EEV) for advanced array testing. For your system, this low noise means more sensitivity and higher dynamic range.

Very Low Contrast Imaging
Many samples imaged in TEM systems have extraordinarily low contrast. Achieving sufficient statistics to image this low contrast requires detection of the largest number of electrons possible. To do this, a camera must have the largest possible well capacity and just the right signal gain. Too much gain and you will saturate the CCD before accumulating

Very Sensitive Samples
For demanding situations where more flux may damage the sample, we provide back illuminated CCD camera systems. These systems have up to three times the QE of front illuminated CCD cameras.

Special Applications

Computer Interface and Software
As a leader in high performance digital imaging, Princeton Instruments offers digi-

Superior Systems at a Lower Cost
Princeton Instruments is the world's largest manufacturer of cooled CCD cameras. Because we sell to a large number of applications, we have the volume to achieve low cost manufacturing. This allows us to offer higher resolution CCD arrays for a given budget. To see which CCD is best for you, call your Princeton Instruments representative today.

Safety
All Princeton Instruments cameras are available with lead shielding for 120 keV operation. Additional shielding for operation at up to 400 keV can be provided for an additional charge. 91

MicroMAX system mounted on a Philips TEM in Princeton Instrument's TEM Lab Fax: 609-587-1970 Princeton Instruments