Radiation hardness

An important problem of the large-scale application of liquid-filled ionization chambers is the radiation hardness of the liquids. On one hand, once the chambers are sealed they are expected to function for several years without deterioration of performance on the other hand, in the environment of high energy physics accelerators. 

In liquefied rare gases, the scintillation light represents a powerful source of energetic photons which are capable of initiating photochemical reactions with dissolved impurities or at the insulators or the walls of the chamber. 

Albrow, M. G., Apsimon, R., Aubert, B., Bacci, C., Bezaguet, A., Bonino, R., Cennini, R, and Centro, S., et. al.. Performance of a uranium/tetramethylpentane electromagnetic calorimeter, Nucl Instrum. Methods, A265, 303,1988. 

Anderson, D. F., Extraction of electrons from a liquid photocathode into a low-pressure wire chamber, Phys. Lett., 118B, 230,1982. 

Anderson, D. F. and Holroyd, R. A., High rate operation of warm-liquid ionization chambers, Nucl Instrum. Methods, A260, 343,1987. 

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Copper Indium Diselenide. CuInSe2 (CIS) has proven to be one of the most promising thin-film photovoltaic materials. CIS ahoy materials have yielded smah-area (ca 1 cm ) laboratory devices with efficiencies in excess of 17% and large-area (ca 0.5 m ) monolithic integrated modules with efficiencies in excess of 11%, and have shown excehent radiation hardness. 

Numerous uses for PZT/PLZT thin films are under investigation. The device that, as of this writing, is closest to commercialization is a nonvolatile memory. This device, which utilizes a ferroelectric thin-film capacitor integrated onto siUcon circuitry, provides memory retention when the power is off because of the polarization retention of the ferroelectric capacitor. One and zero memory states arise from the two polarization states, — and +F, of the ferroelectric. Because PZT is radiation-hard, the devices are also of interest for military and space appHcations. 

Susceptibility to radiation damage must be considered seriously if reference samples are to be calibrated for use in place of absolute systems. For the measurement of absolute C He, H) cross sections, films of polystyrene (CH) (which is relatively radiation hard) have been used successfiiUy, the RBS determination of carbon providing implied quantitation for the hydrogen present in the film. For a durable laboratory reference sample, however, there is much to recommend a known ion-implanted dose of H deep within Si or SiC, where the loss of hydrogen under room temperature irradiation will be neghgible. 

The irradiation-induced absorption coefficient // may be a better way of evaluating the radiation hardness and it is expressed as ... 

ASTM E668 Standard Practice for Application of Thermoluminiscence-Dosimetry (TLD) Systems for Determining Absorbed Dose in Radiation-Hardness Testing of Electronic Devices... 

Cloetens, P., Barrett, R., Bamchel, J., Guigay, J.P., and Schlenker, M. 1996. Phase objects in synchrotron radiation hard X-ray imaging. J. Phys. D Appl. Phys. 29, 133-146. 

For non-volatile random access memories (NV-RAMs in which the stored information is retained even if power to the chip is interrupted), ferroelectrics serve not just as capacitors (as in the case of the DRAM, described below), but as the memory element itself. Their principal advantages in this application are low-voltage (1.0 V) operation, small size (about 20% of a conventional EEPROM cell - and cost is proportional to size once high-yield production is achieved), radiation hardness (not just for military applications but also for satellite communications systems) and very high speed (60 ns access time in commercial devices, sub-nanosecond in laboratory tests on single cells). 

The wide band gap semiconductor ZnO has attracted much attention in recent years. This is stimulated by the development of transparent electronics, the growing need of emitters and detectors working in the ultraviolet range of the electromagnetic spectrum, and the progress in the realization of ferromagnetic semiconductors with Curie temperatures close to or above room temperature. ZnO is nowadays applied as transparent front contacts of solar cells competing with the commonly used material indium tin oxide (ITO). The low cost of ZnO as well as the radiation hardness make... 

Due to its transparency to a wide range of wavelengths from the infrared to the ultraviolet region, as well as to x-rays, combined with its radiation hardness and mechanical sturdiness, diamond is an ideal choice as a window material for lasers, x-ray sources, etc. A systematic evaluation of properties such as IR absorption, elastic properties, mechanical strength and thermal properties has been carried out to reveal that CVD diamond has significant... 

Radiation hardness Detectors for neutrons and a particles. X-ray lithography masks... 

InP Can be alloyed with GaAs (In ,Gai cAsyPi 3 ) to emit light with wavelength that depends upon stoichiometry Widespread use in light sources for fiber-optic communications at 1.3 pm Some microwave devices, radiation-hard solar cells... 

Low Cost and High Reliability - All components of the spectrometer are fabricated using standard low-cost, thin film, all Nb fabrication process. The final product is packaged in an ultra-reliable cryocooler with a Mean-Time-Between-Failures (MTBF) exceeding 99 years. Superconductor circuits are extremely radiation-hard, which make them attractive for space applications. 

Further, compound semiconductors are enabling new markets such as fiber optic laser communications, cellular phones, cellular faxes, cellular 2-way video, engine (high temperature) mounted devices, radiation hard devices, medical, and full color displays. We can expect compound semiconductors to contribute greatly to the quality of life over the next several decades. 

New SiC FET structures should be developed to take full advantage of the unique properties of SiC. SiC FETs are expected to exhibit radiation hardness superior to Si and GaAs devices [26]. Recent reports of enhancement mode JFETs [19,20] open up the possibility of SiC FET integrated circuits. 

The study of the influence of defects on optical properties of Ge/Si quantum dots (QD) is of great importance for the future use of QD based devices. Recently, an enhanced hardness of the In(Ga)As/GaAs QD structures against particle irradiation as compared to bulk and 2D counterparts has been found [1-3]. No information exists so far on the radiation hardness of the Ge/Si QDs. In this paper we present the influence of the proton irradiation and hydrogen passivation on the photoluminescence (PL) of MBE grown Ge/Si QDs. An enhanced radiation resistance of the QDs as compared to the 2D wetting layer and bulk Si is shown. 

Nanoscale memory elements created for radiation hard, non-volatile memory (using gigantic magnetoresistance technology) have displayed sensitivity to the... 

Cankocak, K. Bakirci, N.M. Cerci, S. Gnhnez, E. Merlo, J.P. Onel, Y. Ozok, F. Schmidt, L Sonmez, N. 2007. Radiation-hardness measnrements of high OH-content quartz fibres irradiated with 24 GeV protons up to 1.25 Grad. CERN Document Server Preprints, 1-10 CMS NOTE 2007/003. 

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