Photek Limited is a specialist manufacturer and global supplier of vacuum based tubes and camera systems for photon detection. Photek manufacture, solar-blind detectors, photomultipliers, streak tubes and a range of associated electronics and camera systems. The company was founded in 1991 by Jon Howorth, Ralph Powell, Martin Ingle, Geoff Holt and Mehmet Madakbas. Photek's manufacturing specialty is fast time-resolution devices using micro-channel plates. Fusion plasma diagnostics collaborations with AWE have improved time resolution to less than 100ps for devices with micro-channel plate amplification. Detectors without an MCP, such as vacuum photo-diodes, can go as low as 55ps time resolution. Specialist devices, such as streak tubes, achieve an even better resolution of 1 picosecond or less but must sacrifice one spatial dimension for timing information.
Notable Projects
Space Missions
Photek detectors have been used in several space missions through collaborations with academic institutions such as the University of Leicester:
Scanning Image Spectrograph, part of the Special Sensor Ultraviolet Spectrographic Imager on DMSP satellites since 2003. NASA - Launched October 18, 2003; November 04, 2006; October 18, 2009; April 14, 2014.
UV Spectrograph, part of the Miniature Integrated Camera And Spectrometer on Deep Space 1. NASA - Launched October 24, 1998.
Photek are partners in the TORCH project at CERN to produce a new detector for the LHCb upgrade. A concurrent collaboration with Arradiance, USA to develop protective vacuum coatings for electron multipliers has shown ALD-coated photomultipliers can cope with the much higher flux required in particle detector applications.
Photek were the first to commercialise Velocity Map Imaging technology, offering VMI ion optics and related instrumentation for physical chemistry and laser physics research applications. VMI is a variation of charged-particle imaging that offers high velocity resolution, unlocking information on fundamental chemical structure or the characteristics of the intense, ultra-short laser-particle interaction. VMI was used as a ‘quantum microscope’ to take the first ever ‘photograph’ inside a hydrogen atom in 2013.
Unusual Applications
Fluorescence imaging of Michaelangelo's David, proves a non-destructive method for chemical testing of artwork surfaces. Using an image intensifier with 5ns time windows after a 1ns 337 nm laser exposure the fluorescence decay was measured over 100ns to obtain a map of the different surface chemicals to reveal ancient repairs and preservation methods.
Bio-photon emission can provide information about chemical processes in living organisms. The low intensity emissions can even be detected after attenuation through other tissue when using an image intensifier with sufficient gain. An image intensifier with 200 um spatial resolution and 10us time resolution was used to analyse the effects of hyperoxia by the bio-photon emission from oxidation reactions. This damage is of particular concern in the brain as it consumes 20% of the oxygen in the body and is composed largely of fatty tissues that are susceptible to this oxidative stress.
