The aim of the EndoTOFPET-US collaboration is the development of an endoscopic TOF-PET system with integrated ultrasound probe. This project became only recently possible due to the evolving miniaturisation of components. Usually, the detectors in positron emission tomography are placed on a ring surrounding the patient. Using SiPMs it is possible to integrate part of the system into a endoscopic probe. Due to the close proximity of this device to the tissue under investigation, it covers a large spatial angle despite its small size. At the same time, the endoscopic probe can be used for ultrasound measurements. Combining both imaging measurements leads to new diagnostic possibilities. A high photon detection efficiency and a efficient coincidence discrimination enforced by a precise time resolution leads to an improved sensitivity. This can be used to reduce the strain for the patient both by lowering the radioactive dose and the examination time. A potential application for this detector are diseases like prostatic or pancreatic cancer.
This novel approach is challenging in many fields. The detector R&D group at KIP is involved in to central fields, data aquisition and detector integration. For data aquisition, fast and reliable electronics is needed to steer and read out the sensors of the inner and outer detector part. The goal is achieve a time resolution of better than 200ps, raising the sensitivity by improving the coincidence discrimination. For this purpose an ASIC chip named STiC is developed which is able to handle 64 channels of the outer plate. At the same time, fast scintillating crystals are required for this purpose and are under investigation.
One major challenge for the detector integration is the development of a detector head comprising all the necessary components like crystals and photo detectors in a compact housing, which is compatible to commercially available endoscopic probes.
PicoSEC-MCNet (Pico-second Silicon photomultiplier-Electronics & Crystal research Marie-Curie-Network) is a Initial Training Network funded by the European Union. Aim of the project is R&D on ultrafast photo detection and its application in the fields of High Energy Physics and Medical Imaging.
A large number of detector techniques, developed for and used in particle physics experiments, has been transferred successfully to other fields like medicine, X-ray imaging, materilas research, astrophysics and others. Such spin-offs are the goal of this program.
The special properties of SiPMs are well suited for the application in high energy physics calorimetry. They are compact, insensitive against influences from external magnetic fields and provide a high gain. Together with the high timing resolution, this makes them also attractive for applications in medical imaging, like positron emission tomography. The TOF information help to increase the sensitivity by improving the coincidence discrimination, with direct consequences for patients and physicians.
For both applications many developments can be shared within the scope of this project. The detector R&D group at KIP partakes in the development of readout electronics and prototyping building both for calorimetry in future particle physics experiments and PET applications for medical imaging.
The Virtual SiPM Laboratory (VSL) is a shared research project from four German Institutes: DESY Hamburg, KIP Heidelberg, MPI Munich, RWTH Aachen and PI Wuppertal. It is funded by the Helmholtz Alliance 'Physics at the Terascale'. The goal is to share and use existing experience in detector development to explore applications of SiPMs in high energy physics projects. This novel technology is a modern alternative to the established photo tubes. In the VSL, an infrastructure is provided for a complete characterization of these devices. This will be done both for standalone SiPMs as well as in combination with detector materials like crystals, plastic szintillators and materials emitting Cherenkov light.
Additionally, a mobile setup is developed which can be used as training platform for students. This part of the project is designed as a lab exercise for bachelor and master students, but can also be used by PhD students, thus allowing a broad usage on different levels of knowledge and experience.
The detector R&D group at KIP is responsible for the development of a readout chip for signals from SiPMs. The requirements aim for applications in high energy physics, including low power consumption, low noise level, high SNR, a large dynamic range and a ultrafast timing resolution.
