The radiation hardness of silicon charged particle sensors is compared with single crystal and polycrystalline diamond sensors, both experimentally and theoretically. It is shown that for Si- and C-sensors, the NIEL hypothesis, which states that the signal loss is proportional to the Non-Ionizing Energy Loss, is a good approximation to the present data. At incident proton and neutron energies well above 0.1 GeV the radiation damage is dominated by the inelastic cross section, while at non-relativistic energies the elastic cross section prevails. The smaller inelastic nucleon-Carbon cross section and the light nuclear fragments imply that at high energies diamond is an order of magnitude more radiation hard than silicon, while at energies below 0.1 GeV the difference becomes significantly smaller.
Diamond is more and more used as detector material for particle detection. One argument for diamond is its higher radiation hardness compared to silicon. Since various particles have different potential for radiation damage at different energies a scaling rule is necessary for the prediction of radiation damage. For silicon detectors the non-ionising energy loss (NIEL) is used for scaling the effects of different particles. A different way of predicting the radiation damage is based on the Norget-Robinson-Torrens theorem to predict the number of displacements per atom (DPA). This provides a be…
The radiation hardness of the AToM chips of the BaBar Silicon Vertex Tracker has been investigated by means of irradiations with photons from a 60Co source and 0.9 GeV electrons. The increase in noise and the decrease in gain of the amplifier have been measured as a function of the applied capacitive load and the absorbed dose. Different beam intensities have been used to study the effect of different dose rates to the AToM radiation damage. The chip digital functionalities have been tested up to a dose of 5.5 Mrads for the 60Co photons and 9 Mrads for the 0.9 GeV electrons. In addition a pede…
Radiation hardness is an important requirement for solid state readout devices operating in high radiation environments common in particle physics experiments. The MEGII experiment, at PSI, Switzerland, investigates the forbidden decay $μ^+ \to \mathrm{e}^+ γ$. Exploiting the most intense muon beam of the world. A significant flux of non-thermal neutrons (kinetic energy $E_k\geq 0.5 ~MeV$) is present in the experimental hall produced along the beamline and in the hall itself. We present the effects of neutron fluxes comparable to the MEGII expected doses on several Silicon PhotoMulitpliers (Si…
We report radiation hardness tests performed at the Frascati Neutron Generator on silicon Photo-Multipliers, semiconductor photon detectors built from a square matrix of avalanche photo-diodes on a silicon substrate. Several samples from different manufacturers have been irradiated integrating up to 7x10^10 1-MeV-equivalent neutrons per cm^2. Detector performances have been recorded during the neutron irradiation and a gradual deterioration of their properties was found to happen already after an integrated fluence of the order of 10^8 1-MeV-equivalent neutrons per cm^2.
Recent progress in active-edge technology of silicon sensors enables the development of large-area tiled silicon pixel detectors with small dead space between modules by utilizing edgeless sensors. Such technology has been proven in successful productions of ATLAS and Medipix-based silicon pixel sensors by a few foundries. However, the drawbacks of edgeless sensors are poor radiation hardness for ionizing radiation and non-uniform charge collection by edge pixels. In this work, the radiation hardness of edgeless sensors with different polarities has been investigated using Synopsys TCAD with X…
To prevent excessive radiation damage to its Silicon Vertex Tracker, the BaBar experiment at SLAC uses a radiation monitoring and protection system that triggers a beam abort whenever radiation levels are anomalously high. The existing system, which employs large area Si PIN diodes as radiation sensors, has become increasingly difficult to operate due to radiation damage. We have studied CVD diamond sensors as a potential alternative for these silicon sensors. Two diamond sensors have been routinely used since their installation in the Vertex Tracker in August 2002. The experience with these s…
The resolution function of a spectrometer based on a strongly bent single crystal (bending radius of 10 cm or less) is evaluated. It is shown that the resolution is controlled by two parameters, (i) the ratio of the lattice spacing of the chosen reflection to the crystal thickness and (ii) a single parameter comprising crystal thickness, its bending radius, and anisotropic elastic constants of the chosen crystal. Diamond, due to its unique elastic properties, can provide notably higher resolution than silicon. The results allow to optimize the parameters of bent crystal spectrometers for the h…
In the future ATLAS Inner Tracker, each silicon strip module will be equipped with a switch able to separate the high voltage supply from the sensor in case the latter becomes faulty. The switch, placed in between the HV supply and the sensor, needs to sustain a high voltage in its OFF state, to offer a low resistance path for the sensor leakage current in the ON state, and be radiation hard up to 1.2e15 neq/cm2 along with other requirements. While GaN JFETs have been selected as suitable rad-hard switch, a silicon vertical HV-JFET was developed by Brookhaven National Laboratory as an alternat…
Influence of tip materials on the friction force microscopy of epitaxial graphene on SiC(0001): comparison of diamond and silicon tips in experiments and atomistic simulations
Radiation Hardness of Commercially Available NUV-MT Silicon Photomultipliers
University of Hamburg（汉堡大学）；NCSR “Demokritos（德谟克利特国家研究中心）；Institute of Nuclear and Particle Physics（核与粒子物理研究所）；School of Physics and Astronomy, University of Birmingham（伯明翰大学物理与天文学学院）
CVD diamond is an attractive material option for LHC vertex detectors because of its strong radiation-hardness causal to its large band gap and strong lattice. In particular, pixel detectors operating close to the interaction point profit from tiny leakage currents and small pixel capacitances of diamond resulting in low noise figures when compared to silicon. On the other hand, the charge signal from traversing high energy particles is smaller in diamond than in silicon by a factor of about 2.2. Therefore, a quantitative determination of the signal-to-noise ratio (S/N) of diamond in compariso…
The development of IBIC microscopy at the 100 kV ion implanter of the University of Torino (LIUTo) and the application for the assessment of the radiation hardness of a silicon photodiode
Influence of the prolonged irradiation by fission products of 252Cf radionuclide on the operational parameters of silicon-lithium Si(Li) p-i-n detectors, Si surface barrier detectors and Si planar p+n detector was investigated. The obtained results revealed a linear shift of the fission fragment peaks positions towards the lower energies with increase of the irradiation dose for all investigated detectors. The rate of the peaks shift was found to depend strongly on the detector type and the strength of the electric field in the detectors active region, but not on the temperature of irradiation…
In this work we study the performance of silicon photomultiplier (SiPM) light sensors after exposure to the JULIC cyclotron proton beam, of energy $\sim$ 39 MeV, relative to their performance before exposure. The SiPM devices used in this study show a significant change in their behavior and downward shift of their breakdown voltage by as much as $\sim$ 0.4$\pm$0.1 V. Single photon measurements appear to be no longer possible for the SiPMs under study after exposure to a dose of $\sim$ 0.2 Gy (corresponding to an integrated proton flux of $\sim$$ϕ_{p}$=1.06x10$^{8}$ p/cm$^{2}$). No visible dam…
The European X-ray Free Electron Laser (XFEL) will deliver 27000 fully coherent, high brilliance X-ray pulses per second each with a duration below 100 fs. This will allow the recording of diffraction patterns of single molecules and the study of ultra-fast processes. One of the detector systems under development for the XFEL is the Adaptive Gain Integrating Pixel Detector (AGIPD), which consists of a pixel array with readout ASICs bump-bonded to a silicon sensor with pixels of 200 μm \times 200 μm. The particular requirements for the detector are a high dynamic range (0, 1 up to 10E5 12 keV p…
The utilisation of crystalline semiconductor materials as detectors and devices operating in high radiation environments, at the future particle colliders, in space applications, in medicine and industry, makes necessary to obtain radiation harder materials. Diamond, SiC and different AIIIBV compounds (GaAs, GaP, InP, InAs, InSb) are possible competitors for silicon to different electronic devices for the up-mentioned applications. The main goal of this paper is to give theoretical predictions about the behaviour of these semiconductors in hadron fields (pions, protons). The effects of the int…
High radiation hardness, chemical resistance, high temperature operation capabilities stimulate a growing interest to use diamond materials as detectors of ionizing radiation. Samples of CVD-diamond materials in sizes 12 square mm and 4 square mm with thickness from 50 microns up to 500 microns have been grown in INR RAS using a DC glow discharge in a mixture of gases CH4/H2 on molybdenum substrates.
Diamonds are very promising candidates for the neutron diagnostics in harsh environments such as fusion reactor. In the first place this is because of their radiation hardness, exceeding that of Silicon by an order of magnitude. Also, in comparison to the standard on-line neutron diagnostics (fission chambers, silicon based detectors, scintillators), diamonds are less sensitive to $γ$ rays, which represent a huge background in fusion devices. Finally, their low leakage current at high temperature suppresses the detector intrinsic noise. In this talk a CVD diamond based detector has been propos…
The silicon trackers of the ATLAS experiment at LHC (CERN) use optical links for data transmission. VCSEL arrays operating at 850 nm are used to transmit optical signals while PIN arrays are used to convert the optical signals into electrical signals. We investigate the feasibility of using the devices at the Super LHC (SLHC). We irradiated VCSEL and GaAs PIN arrays from three vendors and silicon PIN arrays from one vendor. All arrays can be operated up to the SLHC dosage except the GaAs PIN arrays which have very low responsivities after irradiation and hence are probably not suitable for the…
The Mu2e calorimeter is composed by 1400 un-doped CsI crystals coupled to large area UV extended Silicon Photomultipliers arranged in two annular disks. This calorimeter has to provide precise information on energy, timing and position. It should also be fast enough to handle the high rate background and it must operate and survive in a high radiation environment. Simulation studies estimated that, in the hottest regions, each crystal will absorb a dose of 300 Gy and will be exposed to a neutron fluency of 6 x 10^{11} n/cm^2 in 3 years of running. Test of un-doped CsI crystals irradiated up to…
