Radiation alpha particles

Human Cytogenetic Dosimetry A Dose-Response Relationship for Alpha Particle Radiation from Am-241, Health Physics 37 279-289 (1979). 

Beryllium is an excellent source of alpha particles, which are the nuclei of helium atoms. Alpha particles (radiation) are not very penetrating. These particles travel only a few inches in air and can be stopped by a sheet of cardboard. Alpha particles are produced in cyclotrons (atom smashers) and are used to bombard the nuclei of other elements to study their characteristics. 

Cancer. There has been interest in the potential carcinogenicity of uranium, which emits alpha-particle radiation, although natural, depleted, or enriched uranium or uranium compounds have not been evaluated in rodent cancer bioassays by any route by the NTP (BEIR 1980, 1988, 1990 Hahn 1989 Otake and Schull 1984 Sanders 1986 UNSCEAR 1982, 1986, 1988). However, there is no unequivocal evidence that inhalation, oral, or dermal exposure induces cancers in humans because it is difficult to isolate the... 

The purpose of encapsulation is to protect electronic IC devices and prolong their reliability. Moisture, mobile ions, (eg., sodium, potassium, chloride, fluorides), UV-VIS and alpha particle radiation, and hostile environmental conditions are some of the possible causes of degradation or interaction which could negatively affect device performance or lifetime. Silicon dioxide, silicon nitride and silicon-oxy-nitride, commonly used as passivation layers have excellent moisture and mobile ion barrier properties and are, therefore, excellent encapsulants for devices. As for the... 

Is the roentgen unit used in the measurement of alpha particle radiation Why or why not ... 

The piurpose of encapsulation is to protect the electronic IC devices from moisture, mobile ion contaminants, ultraviolet-visible and alpha particle radiation, and hostile environmental conditions. 

There is an increasing amount of li t sensitive opto-devioes that need UV-VIS protection. Alpha particle radiation is caused by a very low level of uranium and cosmic radiation present as background radiation in the device package and the atmosphere, respectively, and which could generate a temporary soft error in operating dynamic random access memory (DRAM), such as the 64 K, 256 K, 1 and 4 Megabits DRAM devices. This type of alpha particle radiation has become a major concern, especially in high density memory devices. 

The radon gas diffuses through a leather membrane into a cylindrical measurement chamber. In this measurement chamber the charged radon decay products are collected by an electrical field onto a semiconductor silicon-detector and the alpha (particle) radiation is measured spectrometrically. In addition, alpha decays of the radon gas are registered. The alpha decays... 

The same coating is also used to protect static RAM chips from alpha particle radiation, which can cause soft errors, and it reduces the probable failure rate by at least one order of magnitude. Calculations indicated that a 0-5 mm layer would stop 8 MeV alpha particles, and that the coating was fully compatible in all respects. The authors reported that the resultant soft error rate of 0-1% per 1000 h established in service was the lowest level of activity observed for any packaging material presently in use. 

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