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Laser & Diffraction Grating

With the new Laser He-Ne (described in the Laser He-Ne post), you can easily test the physical properties of the diffraction grating. We propose, in particular, to measure the pitch of the grating through the measurement of the diffraction produced on the He-Ne laser beam. The Diffraction Grating When a …

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“Soft” and “Hard” Components of Cosmic Rays

Cosmic rays are energetic particles coming from outer space. The Earth and any other spatial body, as well as satellites and astronauts in orbit, are exposed to cosmic rays. The cosmic rays nature is very diverse (the kinetic energy of the particles of cosmic rays is distributed over fourteen orders of magnitude), as …

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Cosmic Rays & Statistics

The arrival and detection of cosmic rays in a detector is a random process and as such follows a distribution law characteristic of random events. Particularly when the expected number of events in a given time interval is small, then this number should follow Poisson’s statistical distribution. Poisson Distribution Poisson …

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Laser He-Ne

Finally at PhysicsOpenLab the Helium–Neon Laser has arrived ! A helium–neon laser or HeNe laser, is a type of gas laser whose gain medium consists of a mixture of 85% helium and 15% neon inside of a small bore capillary tube, usually excited by a DC electrical discharge. The best-known and most widely used HeNe laser operates at …

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Scintillation Crystals

At PhysicsOpenLab we use many scintillation crystals, mainly coupled with PMTs or SiPMS, to detect particles or radiation. In this post we want to describe the scintillation crystals we normally use in our detectors. A scintillator is a material that exhibits scintillation (the property of luminescence), when excited by ionizing radiation. Luminescent materials, when struck by …

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Bremsstrahlung Radiation

Introduction Bremsstrahlung (from bremsen “to brake” and Strahlung “radiation”; i.e., “braking radiation” or “deceleration radiation”) is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charged particle, typically an electron by an atomic nucleus (as depicted in the image above). The moving particle loses kinetic energy, which is converted into a photon, thus satisfying the law of conservation of energy. …

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X Ray Proportional Counter

The proportional counter is a type of gaseous ionization detector device used to measure particles of ionizing radiation. The key feature is its ability to measure the energy of incident radiation, by producing a detector output that is proportional to the radiation energy; hence the detector’s name. It is widely used where energy levels of incident radiation must be known, such …

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Analysis of a Fukushima Soil Sample

Fukushima Daiichi nuclear disaster The Fukushima Daiichi nuclear disaster  was an energy accident at the Fukushima Daiichi Nuclear Power Plant in Fukushima, initiated primarily by the tsunami following the Tōhoku earthquake on 11 March 2011. Immediately after the earthquake, the active reactors automatically shut down their sustained fission reactions. However, the tsunami disabled the emergency generators that would have provided power to control and operate …

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Gamma Activity Measures

The image above, taken from the Amptek site, shows some gamma spectra: uranium, thorium, background, …. Gamma spectrometry is a powerful technique for the analysis and identification of isotopes. With some caution you can also do quantitative analysis and measurements of activity. Even in this blog we have already tried …

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Measurement of Potassium Isotope K40 Activity

Isotope Potassium 40K As we know, bananas are rich in potassium! What maybe not everyone knows is that potassium in nature is present with three isotopes: 39K (93,3%), 40K (0,0117%) and 41K (6,7%), 40K potassium is unstable and decades in beta mode. This means that potassium present in nature, even that contained in bananas …

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Alpha Activity Measures

Equipment The apparatus has been already described in the post DIY Alpha Spectrometer. The picture below shows the measuring chamber with the alpha detector and the connection to the vacuum pump. There is also an electronic part (not shown in the picture) for the amplification and processing of the signal …

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Cesium 137 Activity in Contaminated Soil

A bit of History … On 26 April 1986, in Chernobyl, Ukraine, the most serious accident ever occurred in a nuclear power plant. For a series of events, partly caused by human errors, partly due to design shortcomings, the fusion of the reactor core occurred, followed by a very strong …

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X Ray Spectroscopy with PIN Photodiode

A PIN diode (p-type, intrinsic, n-type diode) is a diode with a wide region of intrinsic semiconductor material (undoped) contained between a p-type semiconductor and an n-type semiconductor. The advantage of a PIN diode is that the depletion region exists almost completely within the intrinsic region, which has a constant …

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Tunnel Effect

From Wikipedia : Quantum tunneling or tunneling refers to the quantum mechanical phenomenon where a particle tunnels through a barrier that it classically could not surmount. This plays an essential role in several physical phenomena, such as the alpha decay and the nuclear fusion that occurs in main sequence stars like the …

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