Objective
The overall objective is to achieve improvements in the performance of photomultiplier photocathodes by introducing surface structure into the cathode design. The basis of the innovation is an optical light trap of cones or ridges on the scale of the wavelengths detected. This first phase is intended to model the concept, and experimentally assess the risk factor for successful development. The second phase will optimise the process. There have been major improvements in cathode materials and minor changes from geometrical structures, but no method has offered total absorption throughout the spectral range.
All photocathodes produced so far involve a compromise between total optical absorption of the incoming light and electron extraction from the photocathode. Only for very high optical absorption coefficients, coupled with high photon energies, as found in the vacuum ultra-violet, can one fabricate a photocathode, which is both absorbing and sufficiently thin to allow electron extraction. However, for standard PM tubes the overriding requirement is to use thin films from which electrons can be extracted. The consequence is a cathode layer which is too thin to give total absorption of the light for long wavelengths, as is visibly apparent since the photocathodes are semi-transparent and only slightly coloured. A solution to the problem would imply higher performance PM tubes over a wide spectral range, so the benefits of PM speed of response and very high gain could be exploited.
However, the present proposal offers an innovative and simple solution, which, if it can be implemented, should achieve three aims.
Firstly, the quantum efficiency of conventional tubes would be enhanced from a present maximum of 25 to 30%, to near 50%. Secondly, the major fall in performance at the longer wavelengths (e.g. by say 800nm) which is primarily the result of non-absorption of the light, would be overcome, and high photocathode efficiencies might be maintained out to these longer wavelengths. Thirdly, the long wavelength limits of the current photoemissive materials are unexploitable, even though some sensitivity exists out to wavelengths as long as 1.6 microns. Enhancement of the optical absorption would improve this performance for the existing long wavelength tubes, and potentially extend the range of all the current red/near-IR response tubes. The proposed idea is simple, but technologically could not have been implemented until very recently, as for example it is planned to use a combination of pulsed laser ablation via phase masks, followed by ion beam machining, for which suitable laser and beam systems did not exist until now.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
- natural sciences mathematics pure mathematics topology
- engineering and technology mechanical engineering manufacturing engineering subtractive manufacturing
- engineering and technology materials engineering coating and films
- natural sciences physical sciences optics laser physics pulsed lasers
- natural sciences physical sciences theoretical physics particle physics photons
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Programme(s)
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Topic(s)
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Call for proposal
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
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Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Funding Scheme
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Coordinator
BN1 9QG Brighton
United Kingdom
The total costs incurred by this organisation to participate in the project, including direct and indirect costs. This amount is a subset of the overall project budget.