Radiation damage of SiPMs Garutti, E.; Musienko, Yu
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2019, Letnik:
926
Journal Article
Recenzirano
Odprti dostop
The current understanding of radiation tolerance of Silicon Photomultipliers (SiPMs) is reviewed. Radiation damage in silicon sensors is briefly introduced, surface and bulk effects are separately ...addressed. Results on the operation of irradiated SiPMs with X-ray, gamma, electron, proton and neutron sources are presented. The most critical effect of radiation on SiPMs is the increase of dark count rate, which makes it impossible to resolve signals generated by a single photon from the noise. Methods to characterize irradiated SiPMs after their single photo-electron resolution is lost are discussed. Due to the important similarity in the operation below the breakdown voltage, studies on radiation damage of avalanche photo-diodes (APD) are also reviewed. Finally, ideas are presented on how to approach the development of radiation hard SiPMs in the future.
In this work, the effects of 60Co γ-ray irradiation on high resistivity p-type diodes have been investigated. The diodes were exposed to dose values of 0.1, 0.2, 1, and 2MGy. Both macroscopic (I–V, ...C–V) and microscopic investigations, by means of Thermally Stimulated Current (TSC) and Deep Level Transient Spectroscopy (DLTS) techniques, were conducted to characterize the radiation-induced changes. The investigated diodes were manufactured on high resistivity p-type Float Zone (FZ) silicon and were further classified into two types based on the isolation technique between the pad and guard ring: p-stop and p-spray. After irradiation, the macroscopic results of current–voltage and capacitance–voltage measurements were obtained and compared with existing literature data. Additionally, the microscopic measurements focused on the development of the concentration of different radiation-induced defects, including the Boron interstitial-Oxygen interstitial (BiOi) complex, the Carbon interstitial-Oxygen interstitial (CiOi) defect, the H40K, and the so-called IP∗.
To investigate the thermal stability of induced defects in the bulk, isochronal annealing studies were performed in the temperature range of 100°C to 300°C. These annealing processes were carried out on diodes irradiated with doses of 1 and 2MGy. Furthermore, in order to investigate the unexpected results observed in the C–V measurements after irradiation with high dose values, the surface conductance between the pad and guard ring was measured as a function of both dose and annealing temperature.
There is a tradeoff between spatial resolution and count sensitivity in SPECT with conventional collimators. Multi-pinhole (MPH) collimator technology has potential for concurrent improvement of ...resolution and sensitivity in clinical SPECT of 'small' organs. This study evaluated a novel MPH collimator specifically designed for dopamine transporter (DAT) SPECT with a triple-head SPECT camera. Count sensitivity was measured with a 99mTc point source placed on the lattice points of a 1 cm grid covering the whole field-of-view (FOV). Spatial resolution was assessed with a Derenzo type hot rod phantom. An anthropomorphic striatum phantom was scanned with total activity representative of a typical patient scan and different striatum-to-background activity concentration ratios. Recovery of striatum-to-background contrast was assessed by the contrast-recovery-coefficient. Measurements were repeated with double-head SPECT with fan-beam or low-energy-high-resolution-high-sensitivity (LEHRHS) collimators. A patient referred to DAT SPECT because of suspicion of Parkinson's disease was scanned with both LEHRHS and MPH collimators after a single tracer injection. The axial MPH sensitivity profile was approximately symmetrical around its peak, although it was shifted 7 cm towards the patient to simplify positioning. Peak sensitivity of the triple-head MPH system in the center of the FOV was 620 cps MBq−1 compared to 225 cps MBq−1 for the double-head fan-beam system. Sensitivity of the MPH system decreased towards the edges of the FOV. The full width of the sensitivity profile at 200 cps MBq−1 was 21 cm transaxially and 11 cm axially. In MPH SPECT of the Derenzo phantom all rods with ≥ 5 mm diameter were clearly visible. MPH SPECT improved striatal contrast recovery by ≥ 20% compared to fan-beam SPECT. The patient scan demonstrated good image quality of MPH SPECT with almost PET-like delineation of putamen and caudate nucleus. SPECT with dedicated MPH collimators provides considerable improvement of the resolution-sensitivity tradeoff in DAT SPECT compared to SPECT with fan-beam or LEHRHS collimators.
In this work, the thermally stimulated current (TSC) technique has been used to investigate the properties of the radiation-induced interstitial boron and interstitial oxygen defect complex by 23-GeV ...(<inline-formula> <tex-math notation="LaTeX">E_{\text {kin}} </tex-math></inline-formula>) protons, including activation energy, defect concentration, as well as the annealing behavior. At first isothermal annealing (at 80 °C for 0-180 min) followed by isochronal annealing (for 15 min between 100 °C and 190 °C in steps of 10 °C), studies had been performed in order to get information about the thermal stability of the interstitial boron and interstitial oxygen defect in 50-<inline-formula> <tex-math notation="LaTeX">\Omega </tex-math></inline-formula>cm material after irradiation with 23-GeV protons to a fluence of <inline-formula> <tex-math notation="LaTeX">6.91\times 10^{13}\,\,{\text {p/cm}^{2}} </tex-math></inline-formula>. The results are presented and discussed. Furthermore, the extracted data from TSC measurements are compared with the macroscopic properties derived from current-voltage and capacitance-voltage characteristics. In addition, the introduction rate of interstitial boron and interstitial oxygen defect as a function of the initial doping concentration was determined by exposing diodes with different resistivities (10, 50, 250, and 2 <inline-formula> <tex-math notation="LaTeX">\text{k}\Omega </tex-math></inline-formula>cm) to 23-GeV protons. These results are compared with data from TSC and deep-level transient spectroscopy measurements achieved by the team of the CERN-RD50 "Acceptor removal project."
Abstract The reciprocity approach is a powerful method to determine the expected signal power of axion haloscopes in a model-independent way. Especially for open and broadband setups like the MADMAX ...dielectric haloscope the sensitivity to the axion field is difficult to calibrate since they do not allow discrete eigenmode analysis and are optically too large to fully simulate. The central idea of the reciprocity approach is to measure a reflection-induced test field in the setup instead of trying to simulate the axion-induced field. In this article, the reciprocity approach is used to determine the expected signal power of a dish antenna and a minimal dielectric haloscope directly from measurements. The results match expectations from simulation but also include important systematic effects that are too difficult to simulate. In particular, the effect of antenna standing waves and higher order mode perturbations can be quantified for the first time in a dielectric haloscope.
Time of flight (TOF) measurements in positron emission tomography (PET) are very challenging in terms of timing performance, and should ideally achieve less than 100 ps FWHM precision. We present a ...time-based differential technique to read out silicon photomultipliers (SiPMs) which has less than 20 ps FWHM electronic jitter. The novel readout is a fast front end circuit (NINO) based on a first stage differential current mode amplifier with 20 Ω input resistance. Therefore the amplifier inputs are connected differentially to the SiPM's anode and cathode ports. The leading edge of the output signal provides the time information, while the trailing edge provides the energy information. Based on a Monte Carlo photon-generation model, HSPICE simulations were run with a 3 × 3 mm 2 SiPM-model, read out with a differential current amplifier. The results of these simulations are presented here and compared with experimental data obtained with a 3 × 3 × 15 mm 3 LSO crystal coupled to a SiPM. The measured time coincidence precision and the limitations in the overall timing accuracy are interpreted using Monte Carlo/SPICE simulation, Poisson statistics, and geometric effects of the crystal.
Abstract
We report on the qualification of a piezo-based linear stage
for the manipulation of positions of dielectric discs in the booster
of the MADMAX axion dark matter search experiment. A first
...demonstrator of the piezo drives, specifically developed for MADMAX,
was tested at room temperature as well as at cryogenic temperatures
down to 4.5 K and inside strong magnetic fields up to 5.3 T. These
qualification measurements prove that the piezo-based linear stage
is suited for MADMAX and fulfills the requirements.
Status report on silicon photomultiplier development and its applications Dolgoshein, B.; Balagura, V.; Buzhan, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2006, Letnik:
563, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The state of art of the Silicon Photomultipliers (SiPM's)—their features, possibilities and applications—is given. The significant progress of this novel technique of photo detection is described and ...discussed.
We present 3D calculations for dielectric haloscopes such as the currently envisioned MADMAX experiment. For ideal systems with perfectly flat, parallel and isotropic dielectric disks of finite ...diameter, we find that a geometrical form factor reduces the emitted power by up to 30 % compared to earlier 1D calculations. We derive the emitted beam shape, which is important for antenna design. We show that realistic dark matter axion velocities of 10-3 c and inhomogeneities of the external magnetic field at the scale of 10 % have negligible impact on the sensitivity of MADMAX. We investigate design requirements for which the emitted power changes by less than 20 % for a benchmark boost factor with a bandwidth of 50 MHz at 22 GHz, corresponding to an axion mass of 90 μ eV. We find that the maximum allowed disk tilt is 100 μ m divided by the disk diameter, the required disk planarity is 20 μ m (min-to-max) or better, and the maximum allowed surface roughness is 100 μ m (min-to-max). We show how using tiled dielectric disks glued together from multiple smaller patches can affect the beam shape and antenna coupling.
PDF
