In the vast panorama of scientific and technological research, one crucial area is that of detectors for ionising radiation. These devices are crucial for a diverse range of applications, from nuclear medicine to particle physics, from radiological safety to materials science. Recently, there have been developments in the evolution of these instruments, with the introduction of a type of semiconductor detector, characterised by micrometric surface apertures: 'Detector with micrometric optical windows', patented by INFN - Istituto Nazionale di Fisica Nucleare (National Institute of Nuclear Physics).

This advanced detector represents a significant breakthrough in the field, as it solves one of the most difficult challenges: to allow the passage of the laser radiation necessary for the characterisation of the instrument, without compromising the transmission of internal electrical signals. In other words, its design allows instruments to be calibrated even in the absence of radiation.

In the following article, we will explore this technology in more depth, analysing its operating principles, its potential applications and the impact it could have in the field of scientific research and ionising radiation technology. We will do this together with Nicolò Cartiglia, Researcher of Physics at the INFN.

"Detector with micrometric optical windows" is one the most viewed projects in February, found in the "Patents" section on the KS 2.0 platform.

Tell us about yourself, your background and role/interests in the world of research?

I am a researcher at INFN, an institute that promotes research in particle physics and fundamental interactions, in Italy. The term 'nuclear' makes one think of reactors but in reality, the institute does not deal with that. We do fundamental physics and Italy is renowned for its national laboratories and for its collaborations in international ones, with the world reference laboratory being CERN in Geneva. So, all our experiments, technological developments and all the studies we do are often aimed at building detectors that are then contextualised at CERN.

'Detectors with micrometric optical windows', for example, are part of the detectors that will be carried out in Geneva around 2035. This is what INFN is all about: fundamental research.

Can you briefly introduce us to what the technology consists of. How it works and how it improves the 'status quo' of technologies currently used in the field of ionising radiation detectors.

What happens in our experiments is that we create a lot of particles and then have to measure them. Think, for example, of those images, usually from CERN, where the collisions of particles from which as many are created are depicted. All those trajectories that are shown are measured because there are detector planes monitoring the passage.

These are normally silicon detectors, to which this very patent applies. Silicon detectors are such that when a particle passes, the signal created by it in the detector is measured. In fact, the detectors are divided up like so many chessboards and according to which square of the chessboard lights up, we know where the particle has passed. Each square on each chessboard is about 100 microns in size.

For reasons of electrical operation, the surface of these detectors is covered with metal to even out the electric fields. The problem is that when you have one of these detectors in the lab and want to try and see if it works, you do not have the particles. From the sky there are cosmic rays but they do not allow efficient control. To measure their operation, you can inject a small amount of light so that you can see the signal.

The problem is that since these detectors are covered with metal, there is no way for the light to be injected because it is shielded by the metal. So, in order to be able to test in the lab whether these detectors work or not, we proposed a metal cover with openings through which the light can pass.

The idea is to redesign the metal layer on the surface in such a way as to have micro-windows to inject a pulse of laser light and see the signal directly in the lab. It is a method to be enable the operation of the detector without the particles.

At the status quo level, this patent improves so many aspects. We design many different types of detectors to see which one works and we need to be able to test them. It is true that it is possible to test detectors in Geneva or Hamburg using test beams, but it is costly and involve huge amounts of organisation. Testing in the lab what is the best prototype is certainly easier, and helps structure the research and development process.

Thus, this patent improves the status quo because it allows the user to be able to test locally without necessarily having to move to another location.

This technology therefore allows a reduction in time and costs. For this reason, all the detectors we make within our studies are equipped with these optical windows. We have a laser whose light beam emulates the passage of a particle. And it is very functional because it is a small instrument with very low power. So, you can keep it on your work table and use it when needed. In fact, when our detectors arrive, we place them under the laser and immediately see the response.

This patent speeds up the transition from prototype to final design. It helps reduce development time.

The detector project with micrometric optical windows: from idea to market potential.

All the sensors and prototypes that are made by our teams are equipped with these optical windows. The problem is that these are all research productions, so the patent issue does not apply. The question is different, for example, if and when 100 square metres of detectors are built and orders of tens of millions of euros are placed. In this case, it will have to be seen whether the companies that win the tenders will agree to put in these optical windows or not.

At research level, on the other hand, everyone uses them.

Sometimes, as we said at the beginning of our interview, patents are written in somewhat complex language compared to how the technology actually works. Knowledge Share tries to make the patent forms easier to interpret, but your technology, for the uninitiated, might be a bit complex to fully understand.

So, I played a game and asked Copilot to explain to me in a simplified way what ionising radiation detectors were. Among the fields of application, it gave me as results:

• Medicine: For diagnostics (such as X-rays) and therapy (such as radiotherapy).
• Industry: For quality control, environmental radiation measurement and safety.
• Scientific research: To study the properties of subatomic particles and cosmic radiation.

Compared to what I see listed on your patent card - testing of charged particle detectors - how do the above points compare, if true?

Let's say, Copilot did a good job because detectors are used to detect particles and they have so many uses. Take position sensors, for example. We find particle sensors everywhere. But it is difficult to know whether the big industries that make sensors will use our detectors or not.

If you need to detect particles, it is certain that you have to use these optical windows, otherwise you cannot prove what you actually did. You risk mounting something on your detector that does not work. So, when you have to detect particles, it is crucial.

Many of the detectors that are used at CNAO (Centro Nazionale di Adroterapia Oncologica), for example, for Hadrontherapy, come from our studies. For X-rays it is different because they react differently.

Project progress: current state of the art and plans for the future. What are you looking for?

We are always very present in research calls. We do a lot of applications in Europe, such as the Horizon and ERC programmes. Then in Italy we participate in many PRIN[G.2] s (Progetti di Rilevante Interesse Nazionale) and all the basic research funded by INFN.

I deal with research so I have not sought industrialisation contacts. Then there are those, for example, who do medical physics, including here at the Institute in Turin, who have been much more active in seeking industrial contacts. Let's say I don't have direct contacts with industry but there are other groups that do.

Spinoff or no-spinoff? If no, why? If yes with whom? (investors/industrial partners?) How much would it need in economic terms?

This in my opinion is not a spinoff project. This is a technology that companies ask for if they are interested in offering their customers one more chance to test. But there is nothing to develop. We have demonstrated the technology with which to do this and it is there. At this point it is the detector vendors who propose, or the customers who ask, that make the difference.

Let's say that I can set up Spin-Off with this patent but I cannot compete with a Japanese company that makes sales of hundreds of millions of euros a year in detectors. I think it is more of a product that goes directly to the customer if they are interested in using it.

PNRR and electronics: investments in Italy. Your thoughts.

The PNRR has some research lines on which the INFN is active but not in particle detectors. INFN is, however, active in other contexts such as computing, democratisation of the internet and others. But we do not participate actively in this field.

As I was saying a moment ago, we participate in various calls for proposals and when we are 'saturated' with resources we stop because we have to and we actually want to spend the resources efficiently, we have to understand how to use them in the best possible way.

Have you received contacts through the KS platform?

I don't know if they would contact me. Probably the Knowledge Share platform is more in direct contact with people working in the Technology Transfer Office. Certainly, it is a tool for mediation and contact between offices with different competences and in the same institution: like researchers and TTOs. It would be interesting to parallel the engagement between the different offices, but it is also synergistic to see how a flow of information and involvement is established between them. Perhaps thanks to the platform.

Discover more about 'Detectors with micrometric optical windows' - INFN: https://www.knowledge-share.eu/en/patents/detector-with-micrometric-optical-window