Course on semiconductor radiation detectors

13 Jul 2026, 08:00 → 17 Jul 2026, 17:30 Europe/Madrid

Aula Magna Enric Casassas (Facultat de Física)

 

The Barcelona Techno Weeks are a series of events that focus on a specific technological topic of interest for both academia and industry. These events include keynote presentations by world experts, networking activities, and a comprehensive course on solid state radiation detection. CERN and ICCUB organized three editions of the Techno Week in the past, which focused on semiconductor radiation detectors in 2016, 2018, 2021 and 2023.

Course on semiconductor detectors

The core of the 8th Techno Week is a comprehensive in-person course on solid state radiation detection, which covers topics such as the physics of interaction of radiation with matter, signal formation in detectors, different solid state radiation and photon detection technologies, detector analog and digital pulse processing readout circuits, detector packaging and advanced interconnect technologies and the use of radiation and photon detectors in scientific and industrial applications. The event also includes a participant poster session, presentations from industry professionals and a series of laboratories and social events.

The next edition will take place from the 13th to the 17th July 2026 and it will be in-person. The course is divided into four sections: Sensors and Interconnects, Microelectronics, Detector Technologies, and Applications.

Objectives

1. Explain fundamentals of interaction of radiation with matter and signal formation.
2. Understand different solid state radiation and photon detection technologies (including monolithic sensors, CMOS imagers, SPAD sensors, etc).
3. Review detector analog and digital pulse processing readout circuits (with emphasis in microelectronics and ASIC design).
4. Provide an insight of packaging and advanced interconnect technologies (hybrid sensors, 3D integration, etc).
5. Survey the use of radiation and photon detectors in industrial applications.
6. Present new trends in radiation and photon detection.

In addition to the lectures from experts, the event includes a participant poster session and presentations from industry professionals combined with a series of laboratories and social events. 

 

Who it is aimed at

The event is aimed at researchers, postdocs, PhD students, and industry professionals working in fields such as particle detectors, astronomy, space, medical imaging, scientific instrumentation, material analysis, neutron imaging, process monitoring and control. It offers a good opportunity for young researchers to meet with senior experts from academia and industry.

Lecturers

• Gerard Ariño-Estrada (IFAE)
• Rafael Ballabriga (CERN)
• Marco Carminati (Politecnico di Milano)
• Edoardo Charbon (EPFL)
• Perceval Coudrain (CEA)
• David Gascón (ICCUB)
• Alberto Gola (FBK)
• Sergio Gómez (UPC)
• Carlos Granja (Advacam, VSB-TU Ostrava)
• Daniel Hynds (U. of Oxford)
• Boris Korzh (U. Geneva)
• Carla Marin (ICCUB)
• Andrei Nomerotski (CTU)
• Angelo Rivetti (TIFPA and INFN Torin)
• Dennis Schaart (TU Delft)
• Francesc Serra (CNM)
• Walter Snoeys (CERN)
• Renato Turchetta (IMASENIC) 

 

Organization Team 

Scientific Organizing Committee

• Rafael Ballabriga (CERN), Co-Chair
• David Gascón (ICCUB-IEEC), Chair
• Sergio Gomez (Serra Hunter- UPC)
• Daniel Guberman (ICCUB)
• Joan Mauricio (ICCUB)
• Eduardo Picatoste (ICCUB)
• Andreu Sanuy (ICCUB)

 

Local Organizing Committee

• Anna Argudo (ICCUB)
• Esther Pallarés (ICCUB)

 

          

 

ICCUB industrial collaborations in microelectronics and related technologies

There’s a strong industrial participation in the Barcelona Technoweek. Companies participate giving lectures and talks in industrial sessions, in the industrial exhibition and as sponsors. 

Acknowledgements

This event is part of the grant CEX2019-000918-M funded by MCIN/AEI/10.13039/501100011033  

 

 

 

 

Sponsors

 

 

This event is part of the grant ED2024-153684-T funded by MCIN/AEI/10.13039/501100011033

 

 

 

 

Formulari d'inscripció. Informació detallada_eng.docx

Poster Techno Week 2026.pdf

Monday 13 July

08:30 Registration

1 Introduction to interactions of radiation with matter

Speaker: Daniel Hynds

2 Classification of detectors

Speaker: Daniel Hynds

10:50 Coffee break

3 Signal conditioning, digitization and Time pick-off

Speaker: Angelo Rivetti (INFN)

4 Signal conditioning, digitization and Time pick-off

Speaker: Angelo Rivetti (INFN)

12:50 Lunch break

5 ADCs

Speaker: Francesc Serra-Graells (IMB-CNM (CSIC))

6 TDCs

Speaker: Sergio Gómez (UB)

7 Institutional welcome

Speaker: Domènec Espriu (ICCUB)

16:15 Coffee break

Poster session/industrial exhibition

8 Development of a portable 3D gamma coded-aperture spectro-imager

This work aims at developing a portable multimodal gamma imaging prototype for nuclear industry applications. In the research towards a 3D radiological mapping, the
imager combines coded-aperture gamma imaging, spectrometry and 3D localization to achieve 3D gamma imaging.

ID40-GiuliaROSSO-3D_gamma_imaging.pdf

9 Characterisation and expected performance of the LISA particle detector

Characterisation and expected performance of the LISA particle detector

MarinaOrta-LISA_RM-poster.pdf

10 Radiation hard beam monitors based on ultra-thin silicon carbide diodes

The advances in FLASH radiotherapy, which has typical dose rates over 40 Gy/s, demand the development of innovative instrumentation capable of operating under that extreme radiation conditions. Beam monitoring in such environments require detectors that can sustain high particle fluxes while maintaining stability and precision. Moreover, these detectors have to be ultra-thin in order to behave as transmissive radiation detectors. This feature is essential to minimize beam perturbation during irradiation, which will allow to monitor the beam in real time, reducing potential risks to patients in case of system malfunction, and thus improving safety.
In this context, silicon carbide (SiC) has emerged as a promising semiconductor due to its high radiation hardness, its wide band gap, and its thermal and optical stability. In this work, we present the development of the first ultra-thin SiC PIN diodes designed and manufactured at the IMB-CNM through optimized micromachining techniques on a 3µm epitaxial 4H-SIC layer grown over a 6-inch 4H-SIC wafer . These devices have shown to have better performance in demanding radiation conditions than the silicon ones in terms of radiation hardness and signal response [1]. The diodes have been thinned down to a total thickness of 60µm, representing a proof of concept of transmissive SiC diodes.
This work aims to report the first results of the SiC fabrication process for beam monitoring as well as the corresponding electrical characterization.
[1] Celeste Fleta et al 2024 Phys. Med. Biol. 69 095013

11 Gamma-Ray Charge-Sharing Correction in High-Resolution CdTe Detectors via Cluster Circularity Analysis

Fine-pitch semiconductor detectors, including CdTe and CZT arrays, are establishing themselves as the leading technology for high-resolution medical imaging. However, reducing pixel pitches below 200 µm worsens charge-sharing effects, where incoming photon energy distributes across multiple adjacent pixels. This spatial dispersion, more pronounced in sub-200um pixels and gamma-ray energy range, causes signals in many peripheral pixels to fall below the electronic detection threshold, inducing significant spectral degradation and systematic distortion.

To overcome this issue, this study introduces a correction methodology that evaluates the spatial symmetry of pixel patterns using a novel circularity metric. Tested using a 2-mm-thick CdTe crystal coupled to a Timepix3 readout chip, individual photon interactions from Am-241 and Co-57 radioisotopes were classified based on both cluster size (multiplicity) and shape symmetry/roundness (circularity). Morphological assessment revealed that spatial asymmetry directly reflects sub-threshold charge losses.

A two-stage correction algorithm was then implemented to restore spectral performance. First, we categorized the detected events by clustering them according to their multiplicity and circularity, to obtain distinct per-pixel energy spectra for each combination of these parameters. Next, in the intra-multiplicity step, we aligned the spectra with lower circularity values to the reference spectrum with perfect symmetry, for each multiplicity level. Finally, an inter-multiplicity step unifies the spectral response across different cluster sizes. As results, the average per-pixel FWHM improved from 16.70% to 10.05% at 59.5 keV (Am-241) and from 9.64% to 6.73% at 122 keV (Co-57). Given its closed-form geometric formulation, this method offers a practical path toward real-time event-by-event spectral correction.

Luca_Pezzotti_Charge_Sharing_Circularity (1).jpg

12 CROME : Cern Radiation Monitoring System

The CROME (CERN Radiation Monitoring Electronics) system is the new generation of radiation monitoring infrastructure developed by CERN for radiation protection applications. It provides continuous real-time monitoring of ambient dose equivalent rates over nine decades, advanced alarm and interlock functions with very high reliability, long-term data logging through SCADA integration, and embedded edge-computing capabilities for local processing and decision-making. CROME was designed to address the unique challenges of CERN's accelerator environment, where high-energy particle collisions generate complex mixed radiation fields composed of hadrons, neutrons, leptons, and photons across a wide energy range. In addition to monitoring radiation during accelerator operation, the system helps assess residual radioactivity caused by activation of accelerator components and surrounding materials, ensuring safe access for personnel after beam shutdowns. Developed since 2014, CROME aims to progressively replace CERN's legacy radiation monitoring systems and harmonize a network of approximately 800 measurement channels. The system combines fast response times, down to the millisecond, with accurate measurements extending from the nSv/h range over nine orders of magnitude. Through this modernization effort, CROME provides a scalable, reliable, and long-term solution for ionizing radiation monitoring across CERN facilities.

Tuesday 14 July

13 Neural networks for radiation detector processing

Speaker: Marco Carminati (DEIB, Politecnico di Milano/INFN)

14 Neural networks for radiation detector processing

Speaker: Marco Carminati (DEIB, Politecnico di Milano/INFN)

10:45 Coffee break

15 Sensor integration and packaging

Speaker: Perceval Coudrain (CEA/LETI)

16 Sensor integration and packaging

Speaker: Perceval Coudrain (CEA/LETI)

12:50 Lunch break

17 CMOS image sensors

Speaker: Renato Turchetta (imasenic)

18 Hybrid Pixels Detectors

Speaker: Rafael Ballabriga (CERN)

16:15 Coffee break

Poster session/industrial exhibition

19 A low-noise Transimpedance Amplifier for Balanced Homodyne Detection

This poster presents the design of a multi-band, low-noise transimpedance amplifier for balanced homodyne detection in optical squeezing experiments. To facilitate comprehensive real-time system diagnostics, the architecture provides simultaneous readout across four distinct spectral channels: a DC path for local oscillator power monitoring, a high-gain “audio-band” (100 Hz – 100 kHz) sum and difference output for technical noise and vibration analysis, and a radio-frequency difference output (5 MHz – 400 MHz) for quantum state measurement.

Speaker: Marco Toffano (INFN Padova)

20 Overcoming Limitations of Hybrid Pixel Detectors for Clinical X-Ray Imaging

Introduction
Hybrid-pixel detectors (HPDs) and in particular the subclass of photon-counting detectors (PCDs) have recently enabled substantial advances in clinical CT through improved dose efficiency, electronic noise suppression, and spectral imaging capabilities. However, these advantages have not yet translated to planar X-ray imaging, despite its seemingly simpler acquisition geometry.
CT benefits from substantial information redundancy as individual voxels source information across hundreds of detector pixels, making CT comparatively robust against detector imperfections such as dead regions, sensor inhomogeneities, ASIC border effects, calibration errors, and limited spatial sampling. In planar radiography, however, image quality depends directly on the local detector response, making these limitations substantially more critical. Consequently, many of the practical constraints of PCDs remain more pronounced in radiography than in CT, limiting their clinical exploitation.
Employing mechanically super-sampled radiographic acquisition with PCDs (PC-SSI) addresses these challenges by combining defect-aware detector motion and model-based image reconstruction to recover information lost through detector architecture limitations. Beyond mitigating detector defects and spatial sampling constraints, the approach partially decouples reconstructed image resolution from detector pixel pitch. This enables optimization of detector architectures for spectroscopic performance, count-rate capability, and per-pixel functionality without a proportional loss in image resolution.
Material & Methods
A custom-built µCT system equipped with a high-Z GaAs PCD (SANTIS HR 0804 prototype, DECTRIS AG; 500 µm sensor thickness; 75 µm pixel pitch), a micro-focus X-ray tube (MXR Microbox 100, Micro X-ray Inc.), and a beam-hardening calibration unit was used. Detector trajectories were designed to span multiple pixels while avoiding known detector defects and ASIC border regions, thereby averaging out local field non-uniformities within the sensor. The imaging pipeline combined signal-to-equivalent-thickness calibration (STC), enhanced correlation coefficient (ECC) registration for sub-pixel motion estimation, and iterative reconstruction using distance-driven regularized maximum likelihood expectation maximization (MLEM) with total variation regularization.
As a clinically relevant demonstration, the method was evaluated for mammographic imaging, where simultaneous demands on spatial resolution, spectral information, and radiation dose represent a particularly challenging application scenario.
Results
Phantom experiments demonstrated a more than three-fold improvement in effective spatial resolution compared with native detector imaging, resolving structures down to ~20 µm using a detector with a native pixel pitch of 75 µm. In a breast phantom (Mam AI-Sim, PhantomX GmbH), PC-SSI provided improved visualization of calcification-like structures compared with a clinical mammography system (MAMMOMAT B.brilliant, Siemens Healthineers) at equivalent dose and maintained superior visibility at half of the reference dose. Post-mortem mouse radiography demonstrated a substantial improvement in spatial resolution and overall image quality.
By combining information from multiple detector elements for each reconstructed image pixel, the method simultaneously reduced the impact of detector defects and local sensor non-uniformities while improving the robustness of spectral measurements.
Conclusion
PC-SSI addresses several practical limitations that currently restrict the broader adoption of PCDs in clinical radiography. Beyond improving spatial resolution and mitigating detector imperfections, the approach challenges the traditional trade-off between detector pixel pitch and image resolution. This may enable future PCD architectures optimized primarily for spectroscopic performance, count-rate capability, and advanced pixel functionality, opening new opportunities for super-resolved and spectrally enhanced clinical X-ray imaging.

ID57_FriederikeLang_PCDs_clinical_imaging.pdf

21 How to operate a compensated LGAD

We present a parametric analysis and TCAD simulations of the radiation tolerance of compensated LGADs.
In such designs, the gain layer is engineered through compensation of acceptor and donor dopants.
As radiation progressively deactivates these dopants, the objective is to maintain the charge multiplication mechanism beyond the radiation tolerance of conventional LGAD technology, currently limited to $2\times10^{15}$ neutrons for 50 µm-thick sensors.
The conditions under which compensated LGADs may achieve improved radiation hardness with respect to conventional LGAD technology are presented.
Preliminary observations indicate that the donor removal rate exceeds that of the acceptor; if confirmed, compensated LGADs would need to be designed to operate initially under a high external bias, close to the single-event burnout limit.

Speaker: Simone Galletto (Università di Torino)

Simone-Galletto-How-to-operate-a-compensated-LGAD.pdf

22 Real-time dosimetry in electron FLASH radiotherapy using diamond Schottky pixel detectors

POSTER: Real-time dosimetry in electron FLASH radiotherapy using diamond Schottky pixel detectors

ID41-ManonPhilit-Diamond_Pixel_Detector.pdf

23 Improving spatial resolution of rectangular charge-integrating iLGADs using the 𝜂-algorithm

Saverio Silletta∗, Michele Anastasi, Anna Bergamaschi, Martin Brückner, Maria Carulla, Roberto Dinapoli, Thattil Dhanya, Simon Ebner, Simone Emiliani, Khalil Ferjaoui, Erik Fröjdh, Viveka Gautam, Dominic Greiffenberg, Shqipe Hasanaj, Viktoria Hinger, Marius Hürst, Vadym Kedyc,Thomas King, Shuqi Li, Carlos Lopez-Cuenca, Leonid Lunin, Alice Mazzoleni, Davide Mezza,Konstantinos Moustakas, Aldo Mozzanica, Jonathan Mulvey, Martin Müller, Christian Ruder,Bernd Schmitt, Dhanya Thattil, Xiangyu Xie, Jiaguo Zhang

Paul Scherrer Institute, CPS, Villigen, Switzerland
* Corresponding author, saverio.silletta@psi.ch

Resonant inelastic X-ray scattering (RIXS) imaging directly combines spatial and spectral information by targeting specific atoms within complex structures while remaining sensitive to multiple excitations simultaneously. To effectively measure the scattering spectra of many interesting materials a high spatial resolution in one dimension in the soft X-ray regime (<3 keV) on the detector is needed. Sensitivity in this energy range proves challenging for standard silicon detectors [1].

In collaboration with Fondazione Bruno Kessler (FBK) the Paul Scherrer Institute (PSI) has developed inverse low-gain avalanche diode (iLGAD) sensors optimized for soft X-rays. For RIXS applications, iLGAD sensors with a rectangular pixel geometry were developed. The sensor is bonded to a JUNGFRAU ASIC [2] with a 75 μm square pixel pitch, taking advantage of its lownoise readout. The rectangular sensor pixels are mapped onto this square grid resulting in pixels that are elongated in one direction and compressed in the other, giving an effective pixel pitch of 15–25 μm along one dimension. This gives a charge-integrating hybrid pixel detector laid out to detect small features in one dimension at low energies.

Charge-integrating detectors enable improved position reconstruction through interpolation techniques that exploit charge sharing between neighbouring pixels. Using an 𝜂-algorithm a sub-pixel resolution of around 3 μm have been demonstrated with standard silicon sensors [3]. Here, we
apply the same approach within the AARE framework [4] to rectangular iLGAD pixel detectors in the soft X-ray range. We performed a focused beam scan at the PolLux beam line at the Swiss Light Source (SLS) at different pixel pitches and energies. We will present the results, demonstrating a spatial resolution down to 1.8 μm and discuss the effect of pixel geometry and photon energy.

Another approach being studied is the use of machine learning algorithms to determine the photon absorption position. We are planning to use data of the focused beam scan to conduct supervised learning, studying the charge patterns generated by different impact positions. The aim is to improve the spatial resolution compared to the 𝜂-algorithm. Preliminary investigations along these lines are ongoing, and the results, if available, will be presented.

This research was funded in whole or in part by the Swiss National Science Foundation (SNSF) [PZ00P2 223377]. For the purpose of open access, a CC BY public copyright licence is applied to any author accepted manuscript (AAM) version arising from this submission.

Abstract.pdf

Wednesday 15 July

24 Detectors in High Energy Physics

Speaker: Carla Marin (ICCUB)

25 Monolithic Active Pixel Sensors

Speaker: Walter Snoeys (CERN)

10:45 Coffee break

26 Monolithic Active Pixel Sensors

Speaker: Walter Snoeys (CERN)

27 Hybrid pixels Detectors, Photon counting CT readout electronics

Speaker: Rafael Ballabriga (CERN)

12:50 Lunch break

28 Applications in Quantum Science

Speaker: Andrei Nomerotski (Czech Technical University)

29 Applications in Quantum Science

Speaker: Andrei Nomerotski (Czech Technical University)

16:05 Coffee break

30 Industrial talks

18:00 Social event: Barcelona walking tour

20:00 Social dinner

Thursday 16 July

31 Single Photon Avalanche Diodes

Speaker: Edoardo Charbon (EPFL)

32 Cryogenic CMOS Electronics

Speaker: Edoardo Charbon (EPFL)

10:45 Coffee break

33 Silicon Photomultipliers (SiPMs)

Speakers: Alberto Gola (Fondazione Bruno Kessler), Carina Trippl (EPFL)

34 Silicon Photomultipliers (SiPMs)

Speakers: Alberto Gola (Fondazione Bruno Kessler), Carina Trippl (EPFL)

12:50 Lunch break

35 Superconducting Nanowires Single Photon Detectors (SNSPD)

Speaker: Boris Korzh (University of Geneva)

36 Superconducting Nanowires Single Photon Detectors (SNSPD)

Speaker: Boris Korzh (University of Geneva)

16:15 Coffee break

Poster session/industrial exhibition: E-poster session

37 Radiation Environment Characterization with Semiconductors at Inertial Confinement Fusion Facilities

Inertial Confinement Fusion (ICF) generates an intense yield on the order of 10E13 neutrons.
The OMEGA facility at the University of Rochester leverages ICF to investigate stellar matter
phases, fundamental material properties, and radiation-induced damage in semiconductors.
The Neutron Effects Diagnostic (NED), developed at Sandia National Laboratories, enables
testing of novel neutron effects by positioning devices under test at various distances from the
deuterium-tritium fusion target. This exposes a given experiment to the 14-MeV fusion neutron
environment.
This poster presents an overview of OMEGA and the application of semiconductor
detectors—including TimePix and MSND Tiles—to measure dose rates and characterize the
radiation environment inside and outside the NED.
Sandia National Laboratories is a multimission laboratory managed and operated by
National Technology and Engineering Solutions of Sandia, LLC, a wholly owned
subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National
Nuclear Security Administration under contract DE-NA0003525.

BTW_ACastro.pdf

38 Thermally Induced Surface Void Formation at the Germanium/ITO Interface

Thermal processing of germanium-based architectures is essential for optoelectronic devices, yet surface and interfacial instabilities remain poorly understood [1-2]. A major drawback of these thermal processes is the formation of microscopic surface defects, specifically crystallographic pits or voids on Ge (100) surfaces. These irregularities, which vary based on annealing duration and preparation protocols, can compromise the structural integrity and uniformity of the thin films being deposited [4,5].
This work reports morphological and electrical studies of three Ge-based materials' stacks (Ge, Ge/ITO, and Ge/SiO2 /ITO) following thermal treatments at varying temperatures and under different atmospheric conditions.
For the study, n- and p-type Ge <100> wafers of 1-10 ohm*cm are used as reference, followed by the ITO and the SiO2/ITO deposition via RF Magnetron Sputtering. Annealing was performed at temperatures ranging from 200°C to 650°C, comparing a low vacuum environment (0.1 Pa Ar atmosphere) against a 1E5 Pa N2 atmosphere.
Morphological analysis via SEM and TEM revealed spontaneous pit formation in the Ge and Ge/ITO samples annealed in the Ar environment, even at relatively low temperatures. In the Ge reference, pit exhibit a pyramidal shape exposing <111> facets, consistent with surface free energy minimisation. Pit density increases with the temperature, while the average size does not change significantly. The void formation is tentatively attributed to the desorption of volatile GeO, possibly generated by interfacial reaction between Ge substrate and native oxide (GeO2) [3]. Conversely, Ge/ITO samples show pit formation localized at the ITO grain boundaries, with size scaling with the temperature. A different result is obtained for the Ge/SiO2/ITO stack, which remains completely defect-free under the same conditions. Furthermore, comparative tests show that annealing in a 1E5 Pa N2 atmosphere suppresses the pit formation across all the three systems.
Finally, electrical characterization indicates that this defect nucleation directly correlates with changes in electrical properties, specifically altering the sheet resistance.
Understanding these thermally driven morphological changes provides a critical framework for optimizing stable, defect-free germanium interfaces required for next-generation optoelectronic applications.

[1] C. Claeys, E. Simoen, Germanium-Based Technologies: From Materials to Devices, Elsevier, Amsterdam, 2007.
[2] L. Liyu, and X. Wang. "Germanium/Silicon Single Photon Avalanche Diodes for SWIR Applications: A Review." in IEEE Sensors Journal 25-13, (2025); pp. 23499 - 23513.
[3] Wang, S.-K. (2022). Kinetic Studies in GeO2/Ge System: A Retrospective from 2021 (1st ed.).
[4] L. Persichetti et al. "Formation of extended thermal etch pits on annealed Ge wafers", in Applied Surface Science, 462 (2018); pp. 86-94.
[5] P. Paphawee, and S. Kanjanachuchai. "Morphologies of Ge (100) surface annealed in nitrogen, forming gas, and vacuum", in Surfaces and Interfaces, 66 (2025); 106523.

Speakers: Dr Salvatore Antonino Lombardo (CNR-IMM), Dr Stefania Maria Serena Privitera (CNR-IMM)

Ge.jpg

ITO.png

Final e-poster AnnaLoZito_Thermal_Induced_Void_Formation_Ge.png

39 Timepix4 measurements in scattered beams from electron FLASH radiotherapy

This work presents the first tests performed with the Timepix4 detector in scattered electron beams used for FLASH radiotherapy. Unlike conventional radiotherapy, FLASH delivers radiation at ultra-high dose rates, where the temporal structure of the beam plays a key role in the radiobiological response. Since standard dosimetry devices face important limitations under these conditions, Timepix4 was investigated as a potential tool for beam monitoring and characterization. Measurements carried out at the Mobetron accelerator at CHUV demonstrated that the detector can resolve individual pulses and provide detailed timing information, including pulse frequency, pulse width, and intensity. The results showed good agreement with the nominal machine parameters and revealed pulse-to-pulse variations in high dose rate operation that could be relevant for ensuring beam reproducibility.

In addition, Timepix4 was used to study the characteristics of the scattered radiation field and to compare conventional and high dose rate modalities. Particle cluster analysis showed no statistically significant differences between the two modes, supporting the use of measurements from either modality for future ambient dose assessments. Measurements outside the treatment room also demonstrated the capability of the detector to detect radiation levels below the sensitivity of conventional monitoring systems and to resolve individual beam pulses. Although saturation effects and readout limitations were observed at high particle rates, correction methods partially restored linearity. Ongoing work focuses on understanding the detector rate capability and optimizing measurements for accurate characterization of the scattered field and future in-beam applications.

40 4DPHOTON, a hybrid MCP-PMT with embedded Timepix4 ASIC as pixelated anode

The 4DPHOTON project is a project funded by the European Research Council (ERC) and coordinated by INFN in collaboration with the University of Ferrara and CERN. The project aims to develop a novel large-area photodetector sensitive to single photons with unprecedented spatial and temporal resolution. The detector is designed to handle photon rates approaching 1 billion of hits over its area of few square centimeters while measuring position and time of arrival of each photon with a spatial resolution better than 10 μm and a sub-hundred ps time resolution.
The 4DPHOTON detector is based on a hybrid architecture combining a high-quantum-efficiency photocathode, a microchannel plate (MCP) amplification stage, and a pixelated CMOS digital readout anode embedding the Timepix4 ASIC. The Timepix4 chip, fabricated in 65 nm CMOS technology, is an array of 512x448 pixels distributed on a 55 μm square pitch over a sensitive area of $\sim$7 cm$^2$. Each pixel integrates analog and digital-front-end electronics, enabling continuous data-driven acquisitions supporting data transmission rates up to 160Gb/s. Detector readout and configuration are both managed by an external FPGA-based data acquisition board.
The capability of the 4DPHOTON detector to provide simultaneous information on the three spatial coordinates and time represents a breakthrough for light imaging applications constrained by the lack of precise 4-dimensional information. In particular the compactness, rate capability, time resolution and high granularity of the detector can pave the way for a new generation of RICH (Ring Imaging Cherenkov) detectors in high-energy physics, allowing a high efficiency particle identification performance in high photon flux environments. Additionally, the detector also has the potential of opening new research paths in life sciences, quantum optics, fluorescence lifetime imaging, and other emerging fields requiring precise single-photon measurements.

41 Development of in-house Ni/Au bumping and innovative flip chip hybridisation technologies for pixel detectors

Within the CERN EP R&D programme and the DRD3 collaboration, new hybridisation approaches are being developed for pixel detectors, aiming at rapid prototyping while ensuring interconnection reliability and scalability. To adapt the pad topography of the chips, an in-house Electroless Nickel–Gold (ENIG) bumping process has been developed at the single-die level, providing the flexibility to accommodate the diversity of chip designs and integration constraints. Different hybridisation approaches are currently under investigation to address the diversity of chip designs and integration constraints. One such approach is anisotropic conductive adhesive (ACA) bonding, in which conductive microparticles dispersed in an adhesive film (ACF) or paste (ACP) provide both electrical and mechanical connections between the sensor and the ASIC through thermocompression using a flip-chip bonder. Another technique under study involves the use of gold stud bumps deposited on the chip pads for electrical interconnection, combined with an epoxy adhesive to ensure mechanical bonding. This work presents recent developments in the ENIG bumping process and flip-chip bonding techniques. Results obtained from daisy-chain test structures, as well as from assemblies based on functional ASICs and sensors, demonstrate promising performance. The reliability of the interconnections has been evaluated through environmental testing in a climate chamber.

Neil-Wood-Ni_Bumps_hybridizations.JPG

Friday 17 July

42 Introduction to fast timing applications in medical physics (basic principles)

Speaker: Dennis Schaart (Delft Uiversity of Technology)

43 Electronics for Fast Detectors

Speaker: Dr David Gascon Fora (ICCUB. Universitat de Barcelona)

10:45 Coffee break

44 Photon counting CT with scintillators

Speaker: Dennis Schaart (Delft Uiversity of Technology)

45 State of the art in PET, trends

Speaker: Gerard Ariño-Estrada (U. of California Davis, IFAE)

13:00 Lunch break

46 Applications in space of radiation detectors

Speaker: Carlos Granja (ADVACAM)

47 Neutron Detection

Speaker: Carlos Granja (ADVACAM)

48 Closing talk

Speakers: David Gascon Fora (ICCUB. Universitat de Barcelona), Rafael Ballabriga (CERN)