E!11309 A disruptive new EDXRF detector system

By the end of 2018 this project is on track with plan. The biggest and most demanding activity has been to design the core element of the project, the integrated circuit (ASIC) that will preprocess the signals from the x-ray sensor. This development is now back on track despite a lot of extra effort due to the fact that we have had to change the process for ASIC production. We have also established the basic architecture for digitization and data reading, and the EU partner in this project has now finished the conceptual design of the hermetic cooling system and simulations of this. At the end of 2019, this project is on track with regard to electronics and mechanics to be developed. The most comprehensive electronics development, the ASIC, has been manufactured and testing has begun, but we have encountered problems in this testing. The chip works mostly correctly and it has also shown good and correct analog response in single pixels, but we have a problem with this response when all 1400 pixels are operating together. We have not yet identified the cause of this, which can often be complicated in such very large and complicated analog circuits. The testing is ongoing and we have made two special moves so far; 1) We have brought in a new wafer from the factory where a special top layer we applied for flip-chip (bump-bonding) mounting is removed in the hope that this could be the cause (which it was not), and 2) we currently flip-chip mount sensors on some ASICs (at Hamamatsu, Japan) so we can test these with real x-ray signals, in the hope that we will at least get closer to the cause of this. Testing by means of the latter has not yet started as we are currently waiting for these sensor-ASIC modules to arrive in December. The rest of the mechanics and electronics development continues in parallel and is otherwise on rails. At the end of March 2020 this project officially ended. The project set out to develop a new detector system for (energy dispersive) X-Ray Fluorescence (EDXRF) analysis with better sensitivity and order of magnitudes faster than today's state-of-the-art technology. Project partner BSI have successfully carried through their development according to the plan and the objectives. Enxense?s developments have also been carried out according to the objectives, but there have been major challenges with the performance of the all important ASIC. This forced a change in the development priorities last year - towards much more efforts than planned in trying to make this ASIC fully working. We made much progress with this but did not obtain full succeed before this Eurostars project ended. We therefore thus far also haven?t reached the final overall technical result objectives. After much efforts, the ASIC was made to function reasonably - but yet with instabilities and imperfections. With an extension of the project a functioning EDXRF instrument could be made based on it, as a prototype that might have delivered reasonable results. But it seems not realistic that this ASIC could be used in a selling product. After months of testing efforts we have not been able to determine the root cause for the ASIC problem. This is a major setback for possible continuation, because until knowing what to improve, it cannot be fixed. This is a classic problem in advanced large-chip ASIC design. In our ASIC, significant testing mechanisms was embedded into the design. But the origin of problem is even deeper inside of the pixel than we are able to probe with these means. We observe oscillations but we cannot study them directly and simulations does not reveal the problems. A comprehensive technical report have been made that provides a full overview of the project's achievements and challenges. The current financing of this project ends with the ending of the Eurostars project. It is in the moment unclear if further funding can be found for a continuation.

The project has resulted in increased technical know-how (in particular of a new CMOS process and low noise signal processing). It also has resulted in increased experience with international R&D cooperation. Quite late in the project however we hit a technological roadblock with the all important central ASIC - which we could not fully solve before the project ended, and so the overall goal of developing a fully working complete EDXRF analyzer was not reached. Since we was not able to identify the rood cause of this roadblock, finding more funding to continue this project is uncertain.

This project is about performing the research and development required to realize the primary and secondary objectives described in the previous section. It involves a thorough understanding of the detection technologies used in X-ray fluorescence (XRF) material analysis and how our new technology ideas can improve this and thereby create a market for a new product. The project involves the developments of i) a novel kind of a hybrid pixel detector consisting of a 2D matrix pixel-ASIC in a bump-bonded sandwich with a matched pixel Silicon-sensor which will be developed in this project. It also involves ii) a highly integrated controller and high-speed data-acquisition system to control and read out the X-ray data from the detector, iii) a customized cooled hermetic chamber to cool and enclose the detector, iv) a customized mechanical enclosure of the system, v) customized software and firmware to operate the system and to present the data, that also will be developed in this project. Thorough testing of the system at ultra-high X-ray florescence rates to demonstrate the results is also an integral part of this project.