2009 Nobel Prize Winning Physicists From L to R: Willard S. Boyle, Charles K. Kao, and George E. Smith.
A CCD sensor can be found in scanners, digital cameras, video cameras, and mobile phones. The CCD sensor consists of a matrix of light sensitive photo diodes converting the light into electric charge. The little photo diodes are coupled electrically together (charged coupled device = CCD) and this enables that the charge can be transported from one pixel to the next. This is done column-wise. A good picture describing this process is transporting water via a chain of buckets; the water is always put from one bucket to the next. Outside of the sensor the information is put back into a picture like a mosaic. The invention of this device was 1969, but it took 12 years until the first device was on the market, with 0.3 Megapixels. But they became only a real success in the last 10 years when the world wide digital data transfer picked up speed.
And did this have an impact on particle physics? Yes, definitely! I think the development of the pixel sensors for particle physics definitely profited from the advancements in this field. Semiconductor processes in general had a great impact on the detectors for high energy physics. Only because the market was always asking for even faster chips, with more functionality integrated, the structures within the chips were decreased in the size. And this small size structures give the possibility to design radiation tolerant electronics with a lot of functionality integrated. And with these new technologies we can get the best out of our detectors.
A good example for this development is shown in the picture below. The device is a front end card from the ZEUS calorimeter, developed at the end of the 80s, at a time when not every body had a computer on the desk and long before we thought of mobile phones.
This front-end board digested the signals from 12 channels. Nowadays the functionality of this board could be integrated in a chip of the size of the nail of my small finger, and probably not only for 12 channels, but for 100 channels. One very nice development in the field of pixel detectors was described by Frank just yesterday.
I was really happy to see that the Nobel committee selected this topic and awarded the fathers of the CCD sensors and optical data transmission.
A front-end card from the ZEUS calorimeter for the readout of 12 channels. Development of the end of the 80s.
