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Cosmic Rays on the Dolomites

The link between cosmic rays and mountains has always been tight. Since the beginning of the research it was clear that cosmic rays, coming from deep space, are absorbed by gases in the atmosphere and that they reach the ground modified and weakened. The primary cosmic rays, mainly composed by …

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Antimatter

Antimatter can be bought “online”, perhaps even directly on ebay! But do not expect to receive an antimatter can as the one depicted in the photo above. What you get instead is a capsule containing an infinitesimal quantity of the isotope Sodium 22. This radioactive isotope decays by emitting a …

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Rutherford Scattering

Rutherford scattering is the elastic scattering of charged particles by the Coulomb interaction. It is a physical phenomenon explained by Ernest Rutherford in 1911 that led to the development of the planetary Rutherford model of the atom and eventually the Bohr model. It is now exploited by the materials analytical technique …

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Gold Leaf Thickness with Alpha Spectrometry

With the knowledge of the theory of the interaction of alpha particles with matter it is possible to measure with precision the thickness of a very thin gold foil. In this experiment the principal concern will be the specific ionization and rate of energy loss, dE/dx, of an alpha particle …

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Some Alpha and Beta Spectra

With the help of the spectrometer for alpha particles, described in the post DIY Alpha Spectrometer, we looked at some isotopes and radioactive substances. The main difficulty of the alpha spectroscopy is the preparation of the source: to obtain net lines and good resolutions it is necessary that the active …

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DIY Alpha Spectrometer

Alpha Spectrometry is a fascinating technique because it allows you to have accurate information about the radioactive decay of heavy nuclei and about the physics of the interaction of charged particles with matter. But this is a rather difficult technique, even more difficult than gamma spectrometry. The difficulties of this technique lie …

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Speed of Electromagnetic Signal

The speed of light in vacuum, commonly denoted by c, is independent of the relative speed of the observer and the source of the radiation and therefore assumes the role of universal constant of physics, such as the gravitational constant G, the electron charge, its mass etc. According to current …

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Shot Noise and Electron Charge

The shot noise or granular noise is the electronic noise due to the “corpuscular” nature of the charge. The first study on the shot noise was done by W. Schottky in 1918 examining the elementary fluctuations of the current in vacuum tubes (diodes, triode, etc.). This type of noise is …

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Johnson Noise, Boltzmann Constant and Brownian Motion

When designing and building an electronic apparatus, especially when it is necessary to acquire and process weak signals, generally one follows all precautions in order to eliminate or at least reduce the electronic noise as much as possible in order to maximize the signal – noise ratio (S / N). …

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Broadband Amplifier for PMT and SiPM

We describe, in this post, the use of a MMIC device (Monolithic Microwave Integrated Circuit) as the front-end electronics for the amplification of the signals generated by a photomultiplier. This type of device has the advantage of offering a very wide bandwidth (up to 2 GHz in our case), low …

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