English Posts

Sodium chloride, also known as salt or halite, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35.45 g/mol respectively, 100 g of NaCl contain 39.34 g Na and 60.66 g Cl. The salient features of its structure are: Chloride ions are ccp type of arrangement, i.e., it contains chloride …

One of the first x-rays properties inspected was the ability of x-rays to penetrate solid matter. It has been found that materials such as gases, wood and rubber absorb relatively few x-rays. Conversely, even very thin sheets of heavy metals such as lead or platinum absorb nearly all x-rays incident …

Laue diffraction pattern, in X rays, a regular array of spots on a photographic emulsion resulting from X rays scattered by certain groups of parallel atomic planes within a crystal. When a thin, pencil-like beam of X rays is allowed to impinge on a crystal, those of certain wavelengths will be …

Bragg diffraction (also referred to as the Bragg formulation of X-ray diffraction) was first proposed by William Lawrence Bragg and his father William Henry Bragg in 1913 in response to their discovery that crystalline solids produced surprising patterns of reflected X-rays (in contrast to that of, say, a liquid). They found that these crystals, at certain specific wavelengths and incident …

Recently we acquired a “vintage” equipment, rather old but in full working order : it is the Tel-X-Ometer x-ray diffractometer. A Tel-X-Ometer is an X-ray diffraction system device which is used to detect the absorption and reflection of X-rays i.e. a spectrometer. The device employs an X-ray tube with copper …

With the X-ray tube we have recently acquired we want to try to make a diffractometer ! Introduction X-ray diffraction is one of the most important techniques for the study of crystalline solids. The X-ray diffraction technique is based on coherent elastic scattering : the macroscopic phenomenon of diffraction arises …

The front-end electronics for the acquisition of the signals produced by SiPM (post Front-end Electronics for SiPM) can be conveniently interfaced with a PSoC microcontroller that performs the following functions: Analog signal reading from potentiometer for SiPM bias voltage configuration; Analog reference signal generation for the generation of SiPM bias voltage; …

We have already described in some previous posts examples of projects with SiPM (SiPM Preamplifier, SiPM Gamma Detector , Broadband Amplifier for PMT and SiPM). In this post we want to describe an example of front-end electronics based on a voltage amplifier and a peak & hold circuit designed to read …

Basic SiPM Structure and Operation As we know a SiPM consists of a matrix of small-sized sensitive elements called micro-cells (or pixels) all connected in parallel. Each micro-cell is a Geiger-Mode avalanche photo-diode (GM-APD) working beyond the breakdown voltage (Vbd) and it integrates a resistor for passive quenching. The equivalent …

The purpose of this project is to build a small portable radiation detector with the possibility of being connected to an android smartphone. There are many “apps” available on the google play store that are thought to transform the smartphone into an advanced radiation detector, but to accomplish all this you …

An X-ray tube is a vacuum tube that converts electrical input power into X-rays. X-ray tubes evolved from experimental Crookes tubes with which X-rays were first discovered on November 8, 1895, by the German physicist Wilhelm Conrad Röntgen. The availability of this controllable source of X-rays created the field of radiography, the imaging of partly opaque objects with penetrating radiation. In …

Two “general purpose” photodiodes, two LEDs, some front-end electronics for photodiode reading, and a Theremino master are the tools to create a pair of photogates that can be used for many educational demonstrations in the field of the kinematics. There are so many solutions available on the market (hardware + …

Theory We propose an experiment presented in the CAEN educational catalog. The purpose of the experiment is the determination of the ratio of the effective cross-sections due to Compton and Photoelectric effects as a function of photons energy. In the energy range up to 2 MeV, gamma rays interact with …

From EPIC Crystal Co. we received two scintillator crystals BGO (Bismuth Germanate – Bi4Ge3O12) with cylindrical shape with 6 mm diameter and length 10 mm. With these crystals we would like to try to build a SiPM based radiation detector for beta and  gamma radiation. The BGO scintillato has been described in …

From Wikipedia : In electronics, a transimpedance amplifier (TIA) is a current-to-voltage converter, most often implemented using an operational amplifier. The TIA can be used to amplify the current output of Geiger–Müller tubes, photomultiplier tubes, photo detectors and other types of sensors to a usable voltage. Current-to-voltage converters are used with sensors that have a current response that is more …