Description
Silicon Photomultipliers (SiPMs) are well known as excellent light detectors in the ultraviolet to visible energy range with sub-nanosecond time resolution. Due to their unique characteristics, these devices are increasingly used in high-energy physics, medical and commercial applications. Most SiPMs are implemented as large arrays of Single Photon Avalanche Diodes (SPAD) in a parallel circuit, serving as photon counters.
In recent years, SPADs have been integrated into standard high-volume CMOS processes. This not only allows the production of large volumes of SiPMs at a relatively low cost but also offers the possibility of combining the excellent light detection efficiency and time resolution of SPADs with the flexibility and possibilities offered by CMOS imaging technology. The implementation of CMOS circuitry, extends the properties of standard SiPMs with features such as detailed event hit map, masking of noisy SPADs and in-chip trigger logic and digitalisation. These devices are known as digital SiPMs.
A prototype of a digital SiPM with per-pixel CMOS circuitry was fully developed at DESY in a 150 nm CMOS technology offered by LFoundry. The chip consists of a 32 x 32 pixels main dSiPM, and additional test structures for specific characterisation.
Several studies are in progress on the prototypes and many laboratory measurements are planned. In particular, the sensor response will be studied as the number of active pixels in the digital SiPM array changes. This study will allow a detailed characterization of SPAD arrays not easily accessible using standard SiPMs.
The student will learn how to use the versatile Caribou DAQ system for data acquisition, and will be guided in the operation of the necessary setups for performing Detailed Current/Voltage (IV) and Dark Count Rate (DCR) studies in a temperature and humidity controlled environment. C++ and/or Python will be used for data analysis.
- Physics work: 60%
- Computing work: 40%
- Engineering work 0%
Special Qualifications:
Prior knowledge in Linux, shell, C++, Python and ROOT will be helpful but are not required.
| Field | B3: Development of experimental particle physics equipment (hardware-oriented) |
|---|---|
| DESY Place | Hamburg |
| DESY Division | FH |
| DESY Group | ATLAS |
