Cairn Xenon arc lamps and power supplies
These fabulous products all offer the following features:
- Balanced proprietary low-impedance igniter circuit incorporated inside the lamphouse for low interference emissions at switch on - our light sources will NOT damage your other equipment!
- Suitable for continuous or flash lamps, and can be interconverted by changing lamp mounts.
- Choice of two lamphouses, one optimised for highest light collection, and the other optimised for highest point intensity at focus.
- Both designs use ellipsoidal reflectors for high light-gathering ability without spherical or chromatic aberration.
- Focussed outputs allow simplified optical pathways in most applications, especially those involving monochromators or light guides.
- Precise and easily-adjustable focussing mechanisms.
- Compact 75W or 150W power supplies with universal input voltage range.
- Power supplies incorporate electronic hours counters to monitor lamp usage.
Further Information :
We can now offer two arc lamphouse designs, each of which is suitable either for continuous lamps or for flashlamps. Our flash photolysis systems are described in more detail elsewhere, but the optical efficiency considerations described here are relevant to both applications. The only other point we need to mention here is that the three types of lamp that we currently support (75W xenon or mercury/xenon continuous, 150W xenon continuous, and xenon flash), require different mountings. However, it is quite easy to change the mountings if required.
We originally offered just a 75W lamphouse and power supply, which we designed because our customers were fed up with having their measurement equipment fried by other manufacturers' light sources (more about this below). This is a thoroughly tried and tested design which has been on sale for the best part of a decade now, and it's been very successful. Since it remains suitable for many applications, we shall be continuing its production indefinitely, and even though it's not an overpriced fizzy drink (although it may well also destroy your teeth if ingested in large quantities), we now call it the Cairn Classic light source.
Following the introduction of our Optoscan monochromator, we began selling more systems to customers with interests in high-speed imaging, where the highest possible light intensities are required. As described in our monochromator technical section, the wavelength-selection process requires the input light beam to be focussed to pass through a relatively narrow input slit. Any light which doesn't make it through the input slit is just wasted, so a bright small focussed spot will be more effective than a more diffuse larger one, even though the total light output may well be less. The Classic source actually works pretty well with the Optoscan, but our new Optosource, which has been custom-designed for this application, gives typically 2-3 times more light (the exact improvement depends on the input slit width, which is variable in our design). For other applications, including flash photolysis, the Optosource allows more efficient coupling of the light output into a smaller diameter light guide, which is likely to be translated into a higher light intensity at the experimental sample. From theoretical considerations we expect an approximately two-fold improvement - please watch this page for updates on how this translates into practice.
Both versions use our well-established 75W power supply with constant-power regulation for stable output and long lamp life. The greater heat dissipation capability of the Optosource allows it to be used with 150W lamps as well, for which we have developed a 150W version of the power supply, with otherwise similar characteristics. While the greater optical output of the 150W version may well be useful in some applications, the characteristics of 150W compared with 75W lamps are such that the focussed spot is bigger rather than brighter, and our initial comparisons have shown that the 75W version is actually the better choice for the Optoscan. Both power supplies use switch mode technology for compact size, minimum heat generation and universal power input requirements (90-250V, 50-60Hz).
But for many users the most important feature of our light sources is that they can be used safely in close proximity to any of your other equipment! Although xenon lamps typically run at only about 10-20V, they require a high-voltage trigger pulse of around 30KV to initiate the arc. Some other manufacturers seem to ensure that this trigger voltage reaches the lamp by spraying it around everywhere else as well, which makes short work of any semiconductors in the vicinity, such as those in your computer or your patch clamp, for example. Our approach is to generate the high voltage pulse INSIDE the lamphouse, which is electrically screened, and to do so in a way that is balanced with respect to ground. This is another tried-and-tested feature that has been transferred to the Optosource, so even though this is a new product, we can confidently say that it will NOT damage your other equipment (well, not unless you drop the Optosource on it, as it's a reassuringly substantial beast).
