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SiPM - Avalanche Micro-Pixel Photo Diodes for Frontier Detector Systems
Hadron Physics 2 - WP 28
Start date: 01/01/2009
Activity Type: RTD
Work package acronym: SiPM
Work package title: Avalanche Micro-Pixel Photo-Diodes for Frontier Detector Systems
| Organization legal name | Short name | Activity leaders |
| Gesellschaft für Schwerionenforschung mbH | GSI | H.Orth |
| Istituto Nazionale di Fisica Nucleare | INFN | |
| INFN Laboratori Nazionali di Frascati | INFN-LNF | C.Curceanu |
| INFN Sezione di Pisa | INFN-PI | A. Del Guerra |
| Österreichische Akademie der Wissenschaften | OeAW | J. Marton |
| Univerzita Karlova v Praze | CUNI | R. Leitner |
| Rheinische Friedrich-Wilhelms-Universität Bonn | UBO | U. Thoma |
| Friedrich-Alexander-Universität Erlangen-Nürnberg | FAU | A. Lehmann |
| Justus Liebig Universität Giessen | JLU | R. Novotny |
| Foundation Bruno Kessler | FBK-irst | C. Piemonte |
| Jagiellonian University | UJ | J. Smyrski |
| Institutul Fizica si Inginerie Nucleara - Horia Hulubei | IFIN-HH | M. Bragadireanu |
| Paul Scherrer Institut, Villigen | D. Renker | |
| Zecotek Photonics, Zürich | Z. Sadygov | |
| Joint Institute for Nuclear Research, Dubna | A. Olchevski | |
| Petersburg Nuclear Physics Institute, Gatchina | S. Belostotski | |
| Institute for Scintillation Materials, Kharkov | B.Gryniov | |
| Institute of Nuclear Physics, Moscow | F. Guber | |
| Institute of High Energy Physics, Protvino | V. Ammosov |
1. Objectives
New photon detectors – Geiger mode operated avalanche micro-pixel photo sensor matrices (AMPD), also called silicon photo multipliers (SiPM)* – are ideally suited for future photonics systems in a broad field of basic science in physics, especially in hadron physics. They also have the potential for novel and advanced applications in many other fields. These devices combine performances of traditional phototubes like high quantum efficiency and signal amplification with extremely important features like low-cost voltage supply and electronics. Contrary to photomultipliers the device is insensitive to magnetic fields and mechanically robust thus suitable for harsh environments. Therefore, the possible applications of these devices cover space research, biology, medical diagnostics and eventually environmental technology.
The combination of the expertise of 12 European institutions and 5 from Russia will ensure a powerful collaboration to develop new matrix Geiger-mode APDs with unprecedented performance. The idea is to perform such R&D on prototypes of advanced particles detectors for hadron physics exploiting the strengths of the new photon sensor and pushing against the present deficiencies. We have chosen tree different tasks to pursue:
- T1 Low-level light detection and single photon readout
- T2 SiPM-coupled advanced fiber detectors
- T3 Ultra-fast timing with plastic scintillators for TOF-applications.
The important tasks of investigation with the SiPM sensor are the following:
- Development and test of new SiPMs, integrated in arrays that are compatible with the demands of position sensitive detectors (e.g. single-photon detectors, scintillating fiber detectors, gamma-ray detectors using state-of-the-art crystals like LSO)
- Optimization of the timing performance with resolution below 100 ps
- Development and test of the performance as single photon counters
- Studies of damage effects due to ionizing radiation and device lifetime
- Investigation and characterization of the intrinsic and induced noise behavior
- Development of associated electronics for the supply/readout as well as data acquisition
- Assembly and installation in detector systems working in magnetic fields: characterization of the overall performances and check of the short and long time stabilities on various test beams.
* The sensor has many names in literature. In this project we term it Silicon Multiplier without allusion to any label of a producer.
2. Description of Work and Role of Participants
T1. Low level light detection and single photon readout with SiPM
Detection of Cherenkov radiation requires efficient photon sensors with fast detector response from the visible into the ultraviolet wavelength spectrum combined with single-photon sensitivity. The implementation of Particle Identification (PID in the PANDA experiment is based on the DIRC principle, where the internally reflected light is monitored at the end of the radiators) requires light sensors located in strong magnetic field with limited spatial extensions when using focusing techniques.
We would like to demonstrate the feasibility of modern SiPM arrays for such detector systems. The principal difficulty of SiPM for this application is the single-photon equivalent noise that amounts to 100 kHz up to a few MHz depending on the detector type and on the operating conditions. However this noise can be overcome for the Cherenkov event, which consists of 100 to 200 coincident single- photon hits by implementing a proper majority filter.
We plan to first study the majority filter technique by using a 32-sensor readout with available electronics. Then a matrix of 8 x 8 SiPM sensors (arranged in a 50 x 50 mm2 matrix similar to a multi-pixel photomultiplier) will be constructed. Such a module will be used to study the trigger scenario for coincident fewphoton events.
The leading institutions in this sub-project are GSI and OeAW. IFIN-HH will play an important role solving electronics problems, the other institutions will help in setting up the beam tests and in the analysis of the results.
This task is performed in close collaboration with WP20 (DIRCs).
T2. SiPM-coupled advanced fiber detectors
SiPM are ideally suited for the light readout of fiber detectors in medium- and high-energy physics.The different fiber techniques – inorganic crystalline fiber, organic scintillating fiber or wavelength shifting fiber require different parameters for the photo sensor: size, granularity, spectral sensitivity etc.
a) Inorganic crystalline fibers: The application of inorganic fibers for light transport is presently restricted to organic materials. However, energy- and in particular time-resolution of a single fiber are limited by the low yield of totally reflected luminescence. Inorganic scintillators provide higher light yield and a significantly larger interaction with electromagnetic probes due to the content of high-Z elements. Different and complementary techniques have been developed at CNRS/LPCML and the Institute for Solid-State Physics, Chernogolovka, Russia, which allow for the first time the production of inorganic fibers similar in diameter to the plastic ones. Fibers starting at 2 mm diameter and down to 50µm have been obtained up to 1-2 m length made of several crystals such as LSO, GSO, etc. The very high light output and the consequently excellent timing properties due to the fast decay time and high signal to noise ratio allow applications in hadronic and high energy physics.
Compact trigger, multiplicity or timing detectors can be designed by directly coupling SiPM sensors to the ends of crystalline fibers. This would provide a high photon detection efficiency, excellent timing performance and insensitivity to the magnetic environment. A feasibility study for this readout concept will be performed. An extremely interesting project well suited to develop this technique is a timing detector near the target of the Crystal Barrel spectrometer at ELSA. The leading institutions are UBonn and JLU. There will be a close cooperation with WP27 (SciFi).
b) Organic scintillating fibers: Scintillating fiber detector systems, when placed inside magnetic fields, which is a common situation in hadron physics experiments, need field insensitive photon sensors. The newly developed silicon photomultipliers (SiPMs) are considered to become a standard for this application. However, this technique has first to be developed. It requires: a) Accurate tests of various scintillating fibers to be read out by different SiPM sensors. b) New designs and optimization of readout electronics with DAQ. c) Special attention to precision mechanical design including alignment and optical coupling. As a first step to demonstrate the superiority of SiPMs compared to traditional solutions, a small prototype scintillating fiber detector will be designed, constructed and tested at Frascati or Bonn beams. The performance of this system will be measured using available SiPMs and different types of fibers. At all these development phases, close contact with producing firms of scintillating fibers and SiPMs will be maintained. In such a way the basic expertise for development of new types of SiPM especially designed for hadronic physics will be acquired. As a result of this study, a small prototype of the SiPM-coupled scintillating fiber detector will be delivered. The use of such detectors will be of utmost importance in the AMADEUS experiment at the DAFNE collider. The leading institutions are OeAW, INFNLNF and IFIN-HH. The others will be involved in material research and performing the test measurements.
c) Wave-length shifting fibers: One of the most attractive possible applications of the new photo detectors is the electromagnetic and hadron calorimetry. The expected relatively low cost of SiPMs allows large granularity, excellent space resolution and particle separation. The large gain of an SiPM and the ability to operate in magnetic fields provide the possibility to use these devices in places where the alternative solutions often do not exist. The research in the framework of this project will concentrate on the optimization of SiPM parameters for calorimetric application. Moreover, the presently used scintillating materials do not quite fit to the spectral characteristics of SiPMs. Therefore, the participating team from the Institute of Scintillating Materials at Kharkov will contribute by searching new materials with spectral functions better suited for SiPM. The work on the project will comprise the measurement of SiPM parameters in connection with different scintillating materials (plastic and crystal). It will be used to assist WP29 (HardEx) in the construction of a prototype for the electromagnetic calorimeter of COMPASS at CERN. The leading institutions will be GSI, JINR, CUNI and INFN-PI. The others will contribute to the design and set-up of the electronics and the performance of the test program.
T3. Ultra-fast timing with plastic scintillators for TOF-applications using new SiPMs
In the future FAIR experiments PANDA and CBM, the identification of forwardly emitted particles will be performed with the time-of-flight (TOF) technique. Institutions participating in these two experiments are developing advanced TOF techniques using SiPMs. In PANDA, a TOF-wall is integrated into the Forward Spectrometer in form of large scintillator stripes 7 m downstream of the target. In this project it is proposed to replace the standard vacuum photomultipliers by the new SiPMs and to build a full-size prototype. In such an application, sufficient light is available to exploit the very fast photon response of the individual sensor pixel (< 300 ps), so that a total time resolution of better than 50 ps can be expected. We consider that the use of SiPMs will lead to an advanced and robust TOF system superior to most existing standard implementations.
The optimization of the time resolution and photon efficiency includes a full-scale Monte Carlo simulation which will be validated by experiment. Different light-guide geometries, different sizes and the spectral response of SiPMs will be tested. The design of dedicated read-out electronics is one important task of the project. Ultra-fast preamplifiers, summing amplifiers and constant fraction discriminators will be necessary.
The leading institutions will be UJ, the Petersburg Nuclear Physics Institute, Gatchina (PNPI), the Joint Institute for Nuclear Research, Dubna(JINR), and the Institute of High Energy Physics, Protvino (IHEP). The electronics and the radiation hardness test will be mainly done at PNPI. The other institutions will contribute to the construction of the prototype, to the test measurements and their evaluation.
3. Deliverables
The final deliverables will be well-characterized new photon sensors and sensor arrays for future detector systems in the field of hadronic physics. They are listed below:
| Task | Deliverable | Delivery month |
| Single-photon readout with SiPMs | Design and construction of 64-pixel prototype matrix including readout electronics and tests. | 30 |
| SiPM-coupled advanced fiber detectors | Feasibility studies for new detectors with SiPM readout using: a) crystalline fibers, b) scintillating fibers c) Wave-length shifting fibers. | 30 |
| Ultra-fast timing for TOF- applications | Prototype. Radiation hardness and tests in beam. | 30 |
4. Expected Impact
From the outcome of the Silicon-Photo-Multiplier research, several fields relevant for hadronic physics will profit: readout of Cerenkov and scintillating fiber detectors for tracking devices, readout of calorimeters and of TOF-counters for particle identification.
The regime of very low light with single-photon resolution is typical for Cherenkov radiation detectors. This may be the most challenging application for the SiPM. In task T1, we propose the construction of a prototype Cherenkov photo-sensor. Important requirements are low noise, and high photon detection efficiency. A small number of pixels in the sensor matrix is sufficient since the dynamic range is not critical.
The coupling of SiPMs to fibers is addressed in task T2: The detection of low light levels exist in tracking devices, e.g. scintillating fiber detectors. The requirements to the sensor are similar to those in T1, yet not so stringent; however very good timing is of importance.
Detection of high light levels is encountered in calorimetery with efficient scintillator material adapted to the spectral response of the SiPM. Examples are inorganic and plastic scintillators, tile readout, Shashlik detectors and, very interestingly, the readout of inorganic crystalline fibers. The requirements to the sensor are the high dynamic range that translates into a large number of pixels. The dark count rate is not a crucial issue.
The very fast timing properties of the SiPMs, similar to the best vacuum phototubes, can be exploited in TOF application and will be unique in situations where the ambient magnetic fields are high, as i.e. in PANDA. Task T3 is meant to study a prototype of an advanced TOF wall module using SiPM readout.
The success of the project will have an essential impact on the design and construction of future detectors. It is thus of high importance for researchers working at the Infrastructure Institutions. The development of these techniques will also have an essential impact on medical tomographic techniques, where high segmentation and granularity are important issues, as well as on space
research and on biology.
