Determination of length and position of an object which cannot be seen
PrincipleThis experiment provides training in determining the length and position of an object based on an X-ray image. A metal pin that is embedded in a wooden block is used as the model. This experiment is also an excellent preparatory exercise for demonstrating the principle of computed tomography. Benefits Simulation of a real-life situation in […]
Contrast medium experiment with a blood vessel model
PrincipleWhen a blood vessel model is irradiated with X-rays, the blood vessels themselves are not visible at first. It is only after the injection of a contrast medium that the blood vessels become visible. Tasks Inject a 50% potassium iodide solution into the blood vessel model. Observe the fluorescent screen of the X-ray basic unit […]
Radiographic examination of objects
Principle An X-ray tube produces X-rays that cause a fluorescent screen to emit light. Objects that are located between the X-ray source and the fluorescent screen will be irradiated so that their inner structure becomes visible. If one varies the anode current and voltage, the change in intensity can be observed in a qualitative manner […]
Characteristic X-ray lines of different anode materials / Moseley’s law
Principle Moseley’s law describes the relationship between the energy of the Ka lines of characteristic X-ray spectra and the atomic number. In this experiment, the characteristic X-ray lines of various different anode materials are determined in order to verify Moseley’s law. Tasks Record the X-ray spectra of the three X-ray tubes. Determine the wavelengths and […]
Duane-Hunt displacement law and Planck’s “quantum of action”
Principle X-ray spectra are recorded as a function of the anode voltage. The short wavelength limit of the bremsspectrum is used to determine the agreement with the Duane-Hunt displacement law, and to determine Planck’s “quantum of action”. Tasks Record the intensity of the X-rays emitted by the copper anode at various anode voltages as a […]
K alpha doublet splitting of iron X-rays / fine structure
PrincipleThe polychromatic iron X-ray spectrum is to analyzed by means of a monocrystal. The energy of the characteristic lines is to be determined from the positions of the glancing angles for various orders of diffraction. The separation of the Ka doublet in higher order diffraction is to be examined. Tasks Record the intensity of the […]
K alpha double splitting of molybdenum X-rays / fine structure
Principle The polychromatic molybdenum X-ray spectrum is analyzed by means of a monocrystal. The energy of the characteristic lines is determined from the positions of the glancing angles at various orders of diffraction. The separation of the K a doublet in higher order diffraction is examined. Tasks Record the intensity of the X-rays emitted by the molybdenum […]
Monochromatisation of copper X-rays
Principle The X-rays that are generated by an X-ray tube are polychromatic. Numerous experiments (e.g. Debye-Scherrer experiments concerning crystal structures), however, require monochromatic X-radiation, which can be generated by filtering the X-rays with monocrystals or with the aid of metal foils. Tasks Record the intensity of the X-rays emitted by the copper anode as a […]
Monochromatisation of molybdenum X-rays
Principle The X-rays that are generated by an X-ray tube are polychromatic. Numerous experiments (e.g. Debye-Scherrer experiments concerning crystal structures), however, require monochromatic X-radiation, which can be generated by filtering the X-rays with monocrystals or with the aid of metal foils. Tasks Record the intensity of the X-rays emitted by the molybdenum anode as a […]
Monochromatisation of molybdenum X-rays
Principle The X-rays that are generated by an X-ray tube are polychromatic. Numerous experiments (e.g. Debye-Scherrer experiments concerning crystal structures), however, require monochromatic X-radiation, which can be generated by filtering the X-rays with monocrystals or with the aid of metal foils. Tasks Record the intensity of the X-rays emitted by the molybdenum anode as a […]
The intensity of characteristic X-rays as a function of the anode current and anode voltage
Principle The polychromatic X-radiation from a copper anode is analyzed using a LiF monocrystal according to Bragg. Varying the anode current and anode voltage influences the intensity of the characteristic K a and K b radiation. Tasks Record the intensity spectrum of polychromatic radiation from a X-ray tube with the help of a LiF monocrystal. Determine the intensities of the characteristic K a and K b radiations […]
Characteristic X-rays of tungsten
Principle An X-ray tube with a tungsten anode generates X-radiation that is selected with the aid of a monocrystal as a function of the Bragg angle. A Geiger-Müller counter tube measures the intensity of the radiation. The glancing angles of the characteristic X-ray lines are then used to determine the energy. Tasks Record the intensity […]
Characteristic X-rays of iron
Principle Spectra of X-rays from an iron anode are to be analyzed by means of different monocrystals and the results plotted graphically. The energies of the characteristic lines are then to be determined from the positions of the glancing angles for the various orders of diffraction Tasks Record the intensity of the X-rays emitted by the […]
Characteristic X-rays of molybdenum
Principle Spectra of X-rays from a molybdenum anode are to be analyzed by means of different monocrystals and the results plotted graphically. The energies of the characteristic lines are then to be determined from the positions of the glancing angles for the various orders of diffraction. Tasks Record the intensity of the X-rays emitted by the […]
Characteristic X-rays of copper
Principle Spectra of X-rays from a copper anode are analyzed using different monocrystals and the results plotted graphically. The energies of the characteristic lines are then determined from the positions of the glancing angles for the various orders of diffraction. Tasks Record the intensity of the X-rays emitted by the copper anode as a function of the […]
Fourier optics – 2f arrangement
PrincipleThe electric field distribution of light in a specific plane (object plane) is Fourier transformed into the 2 f configuration. Tasks Investigation of the Fourier transform by a convex lens for different diffraction objects in a 2 f setup. What you can learn about Fourier transform Lenses Fraunhofer diffraction Index of refraction Huygens’ principle Scope […]
Magnetostriction with the Michelson interferometer
PrincipleWith the aid of two mirrors in a Michelson arrangement, light is brought to interference. Due to the magnetostrictive effect, one of the mirrors is shifted by variation in the magnetic field applied to a sample and the change in the interference pattern is observed. Benefits See that magnetic fields can change the geometry of […]
Michelson interferometer – High Resolution
Principle With the aid of two mirrors in a Michelson arrangement, light is brought to interference. While moving one of the mirrors, the alterationin the interference pattern is observed and the wave length of the laser light determined. Benefits Learn about the measurement principle with which gravitational waves can be observed Assemble your own interferometer using invidual optical components […]
Quantum eraser with the Mach-Zehnder interferometer
Principle A Mach-Zehnder-interferometer is illuminated with a laser beam. Circular interference fringes appear on the screens behind the interferometer. If polarisation filters with opposite polarisation planes are placed in the two interferometer paths the interference patterns disappear. Placing another polariser before one of the screens causes the pattern to reappear. Electromagnetic radiation can be described […]
Coherence and width of spectral lines with the Michelson interferometer
Principle The wavelengths and the corresponding lengths of coherence of the green spectral lines of an extreme high pressure Hg vapour lamp are determined by means of a Michelson interferometer. Different double slit combinations are illuminated to verify the coherence conditions of non punctual light sources. An illuminated auxiliary adjustable slit acts as a non […]
Fibre optics
Principle The beam of a laser diode is treated in a way that it can be coupled into a monomode fibre. The problems related to coupling the beam into the fibre are evaluated and verified. In consequence a low frequency signal is transmitted through the fibre. The numerical aperture of the fibre is recorded. The […]
Nd:YAG laser
Principle The rate equation model for an optically pumped four-level laser system is determined. As lasing medium, a Nd:YAG (Neodymium-Yttrium Aluminium Garnet) rod has been selected which is pumped by means of a semiconductor diode laser. The IR-power output of the Nd:YAG laser is measured as a function of the optical power input and the […]
Helium Neon laser, basic set
Principle The difference between spontaneous and stimulated emission of light is demonstrated. The beam propagation within the resonator cavity of a He-Ne laser and its divergence are determined, its stability criterion is checked and the relative output power of the laser is measured as a function of the tube’s position inside the resonator and of […]
Recording and reconstruction of holograms with the optical base plate
Principle In contrast to normal photography a hologram can store information about the three-dimensionality of an object. To capture the three-dimensionality of an object, the film stores not only the amplitude but also the phase of the light rays. To achieve this, a coherent light beam (laser light) is split into an object and a […]
Fabry-Perot interferometer – optical resonator modes
Principle Two mirrors are assembled to form a Fabry-Perot interferometer. Using them, the multibeam interference ofa laser’s light beam is investigated.On moving one of the mirrors, thechange in the intensity distributionof the interfeence pattern is studied. This is a qualitative experiment,to study the shape of different lasermodes and compare it with some photosgiven in this […]
Visualisation of radioactive particles/ diffusion cloud chamber
Principle Radioactivity is a subject in our society which has been playing an important role throughout politics, economy and media for many years now. The fact that this radiation cannot be seen or felt by the human being and that the effects of this radiation are still not fully explored yet, causes emotions like no […]
X-ray dosimetry
Principle Dosimetry, as a subspecialty of medical physics, deals with the determination and calculation of dose rates, which is also of great importance in view of the radiation protection directives. This experiment demonstrates the principle of measurement and it explains the various units of absorbed dose, equivalent dose, and absorbed dose rate. Inside a plate […]
Counter tube characteristics
Principle The counter tube uses the ionising effect of high-energy radiation in order to measure the intensity of the radiation. The counter tube characteristics describe its working range, i.e. the voltage range in which it reliably counts the incoming particles. Tasks Determine the counter tube characteristics of the type B counter tube that is used. […]
Photonuclear cross-section / Compton scattering cross-section
Principle The radiation of 137Cs and 22Na is measured with a scintillation detector and the energy spectrum determined with a multi channel analyzer. The fractions of the spectra caused by Compton scattering and those caused by the photoelectric effect are determined on the basis of their areas. The results are used for determining the ratio of the effective cross-sections and examining […]
Internal conversion in 137m Ba with MCA
Principle The radiation emitted during the decay of the 137Cs isotope is measured with a scintillation detector and the energyspectrum determined with a pulse height analyzer. The spectrum contains fractions due to a gamma-transition and fractions originating from a characteristic X-ray radiation. The areas of the fractions in question are determined and the conversion factor obtained from […]
Energy dependence of the gamma absorption coefficient / Gamma spectroscopy
Principle The intensity of gamma-radiation decreases when it passes through solid matter. The attenuation can be the result of Compton scattering, the photo effect or the pair production. An absorption coefficient can be attributed to each of the three phenomena. These absorption coefficients, as well as the total absorption, are highly energy-dependent. The energy dependence […]
Inverse-square law and absorption of gamma or beta rays with the Geiger-Müller counter
Principle The inverse square law of distance is demonstrated with the gamma radiation from a 60-Co preparation, the half-value thickness and absorption coefficient of various materials determined with the narrow beam system and the corresponding mass attenuation coefficient calculated. Tasks To measure the impulse counting rate as a function of the distance between the source […]
Beta spectroscopy
Principle The radiation of β-unstable atomic nuclei is selected on the basis of its pulses in a magnetic transverse field, using a diaphragm system. The relationship between coil current and particle energy is determined for calibration of the spectrometer and the decay energy of the β-transition is obtained in each case from the β–-spectra. Tasks […]
Electron absorption
Principle The attenuation of an electron particle stream passing through a material layer depends both on the thickness of the layer and on the mass coverage, resp. the “mass per unit area”. It will be shown that the particle flux consisting of electrons of a particular energy distribution decreases with the “mass per unit area”. […]
Energy loss of alpha particles in gases with MCA
Principle A study is made of the connection between the energy E of alpha-particles and the path x travelled by them in air at standard pressure. The measurements recorded enable the differencial energy loss dE/dx to be calculated as a function of x. Tasks The spectrum of a covered 241Am source is measured at a fixed distance […]
Study of the alpha energies of Ra-226 with MCA
Principle An alpha-spectrometer, consisting of a silicon surface barrier layer detector, a preamplifier, a pulse height analyser and a recording device for registration of the spectra is calibrated by means of an open alpha-emitter of known alpha-energy (241Am). The energy spectrum of a radium source which is in equilibrium with its decay products, is recorded […]
Fine structure of the alpha spectrum of Am-241 with MCA/ alpha spectroscopy
Principle The alpha-spectrum of an open 241Am-emitter is measured with a semiconductor a-detector. In connection with a multi channel analyzer the main parts of the spectrum are investigated. Tasks The spectrum of an uncovered 241Am-emitter is recorded with the multi channel analyzer. The energies of the two peaks preceding the principal peak are calculated. The principal peak, corresponding […]
Rutherford experiment with MCA
Principle The relationship between the angle of scattering and the rate of scattering of alpha-particles by gold foil is examined with a semiconductor detector. This detector has a detection probability of 1 for alpha-particles and virtually no zero effect, so that the number of pulses agrees exactly with the number of alpha-particles striking the detector. […]
Alpha energies of different sources with MCA
Principle An alpha-spectrometer, consisting of a photodetector, a preamplifier, a pulse height analyser and a recording device for registration of the spectra is calibrated by means of an open alpha-emitter of known alpha energy (241Am). The energy spectrum of a radium source which is in equilibrium with its decay products, is recorded and evaluated. The […]
Visualisation of radioactive particles/ diffusion cloud chamber
Principle Radioactivity is a subject in our society which has been playing an important role throughout politics, economy and media for many years now. The fact that this radiation cannot be seen or felt by the human being and that the effects of this radiation are still not fully explored yet, causes emotions like no […]
Poisson’s and Gaussian distribution of radioactive decay with Cobra4 (Influence of the dead time of the counter tube
Principle 1) The aim of this experiment is to show that the number of pulses counted during identical time intervals by a counter tube which bears a fixed distance to along-lived radiation emitter correspond to a Poisson´s distribution. A special characteristic of the Poisson´s distribution can be observed in the case of a small number […]
Half-life and radioactive equilibrium
Principle The half-life of a Ba-137 m daughter substance eluted (washed) out of a Cs-137 isotope generator is measured directly and is also determined from the increase in activity after elution. Tasks To measure the activity of the isotope generator as a function of time immediately after elution. To measure the activity of a freshly […]
Atomic Resolution of the graphite surface by STM (Scanning Tunneling Microscope)
Principle Approaching a very sharp metal tip to an electrically conductive sample by applying a electrical field leads to a current between tip and sample without any mechanical contact. This so-called tunneling current is used to investigate the electronic topography on the sub nanometer scale of a fresh prepared graphite (HOPG) surface. By scanning the […]
Basic methods in imaging of micro and nanostructures with AFM (Atomic Force Microscopy)
Principle Approaching a sharp silicon tip mounted on a cantilever to a sample surface leads to an atomic scale interaction. The result is a bend of the cantilever which is detected by a laser. In static mode the resulting deflection is used to investigate the topography of the sample surface line by line using a […]
Band gap of germanium
Prinzip Die Leitfähigkeit einer undotierten Germanium-Probe wird in Abhängigkeit von der Temperatur gemessen. Die Energielücke wird aus den gemessenen Werten bestimmt. Vorteile Die PHYWE Hall Effekt Unit kann auch für Messungen mit n- und p- dotiertem Germanium verwendet werden Einfacher Versuchsaufbau Auch für SEK II geeignet Aufgaben Der Strom und die Spannung werden in einer […]
Hall effect in n- and p-germanium (Teslameter)
Principle The resistivity and Hall voltage of 2 rectangular germanium samples ( n- and p-) are measured as a function of temperature and magnetic field. The band spacing, the specific conductivity, the type of charge carrier and the mobility of the charge carriers are determined from the measurements. Tasks The Hall voltage is measured at room temperature […]
Atomic Resolution of the graphite surface by STM (Scanning Tunneling Microscope)
Principle Approaching a very sharp metal tip to an electrically conductive sample by applying a electrical field leads to a current between tip and sample without any mechanical contact. This so-called tunneling current is used to investigate the electronic topography on the sub nanometer scale of a fresh prepared graphite (HOPG) surface. By scanning the […]
Magnetostriction with the Michelson interferometer
PrincipleWith the aid of two mirrors in a Michelson arrangement, light is brought to interference. Due to the magnetostrictive effect, one of the mirrors is shifted by variation in the magnetic field applied to a sample and the change in the interference pattern is observed. Benefits See that magnetic fields can change the geometry of […]
Ferromagnetic hysteresis with Cobra4
Principle A magnetic field is generated in a ring-shaped iron core by a continuous adjustable direct current applied to two coils. The field strength Η and the flux density B are measured and the hysteresis recorded. The remanence and the coercive field strength of two different iron cores can be compared. Benefits Simple experimental setup and intuitive handling of […]
Dielectric constant of different materials
PrincipleThe electric constant is determined by measuring the charge of a plate capacitor to which a voltage is applied. The dielectric constant is determined in the same way, with plastic or glass filling the space between the plates. Benefits Supplies non-hazardous high voltage Easy experimental set-up due to clear and compact design Clever investment: The […]
Characteristic curves of semiconductors with Cobra4 Xpert-Link
Principle Determine the current strength flowing through a semi-conducting diode. Determine the collector current with the collector voltage for various values of the base current intensity. Benefits Fast and easy experimenting Get to know the behaviour of several types of semiconductors Detailed experiment guide with extensive explanations and step-by-step instructions Measure voltage and current simultaneously […]
Characteristic curves of semiconductors with Cobra4
PrincipleThe current-voltage characteristic of a semiconducting diode is measured. The collector current in dependency on the emitter-collector voltage is measured for different values of base current strength through a NPN transistor. Benefits Fast and easy experimenting Get to know the behaviour of several types of semiconductors Simplified implementation: all pre-settings already prepared Data logging reveals instantaneous […]
Characteristic curves of a solar cell
Principle The current-voltage characteristics of a solar cell are measured at different light intensities, the distance between the light source and the solar cell being varied. The dependence of no-load voltage and short-circuit current on temperature is determined. Benefits Set-up allows quantitative measurement which also takes light intensity into account Set-up allows to avoid but […]
Peltier heat pump
Principle The (cooling capacity) heating capacity and efficiency rating of a Peltier heat pump are determined under different operating conditions. Benefits Open design allows to fully understand function and applications Individual instruments for distinct functions (no “black box”) Key products of the experiment setup can also be used for investigating the Seebeck effect Tasks To determine the […]
Nd:YAG laser
Principle The rate equation model for an optically pumped four-level laser system is determined. As lasing medium, a Nd:YAG (Neodymium-Yttrium Aluminium Garnet) rod has been selected which is pumped by means of a semiconductor diode laser. The IR-power output of the Nd:YAG laser is measured as a function of the optical power input and the […]
Mechanical hysteresis
Principle The relationship between torque and angle of rotation is determined when metal bars are twisted. The hysteresis curve is recorded. Benefits Beyond Hooke’s law Hysteresis – mostly known from the field of magnetism – can be experienced in mechanics Learn the meaning of the words stress, relaxation and equilibrium in a physics context Various […]
Modulus of elasticity / Youngs Modulus
Principle A flat bar is supported at two points. It is bent by the action of a force acting at its centre. The modulus of elasticity is determined from the bending and the geometric data of the bar. Benefits Find out the parameters that give a bar stability Measure the difference of elasticity in various […]
Velocity of ultrasound in solid state material
Principle The velocity of sound in acrylics shall be determined by time of flight reflection technique with an ultrasonic echoscope. The measurements are done by reflection method, on three cylinders of different length. Two measurement series are carried out with ultrasonic probes of different frequencies. Benefits Introductory experiment for echoscopy applications Experiment can be easily […]
Duane-Hunt displacement law
Principle X-ray spectra of an X-ray tube are measured in an energy dispersive manner with a semiconductor detector and with various anode voltages. Duane and Hunt’s law of displacement is verified with the aid of the maximum energy of the bremsspectrum. Tasks Recording of the X-ray spectrum that is emitted by the copper anode for […]
Determination of the lattice constants of a monocrystal
Principle Polychromatic X-rays impinge on a monocrystal under various glancing angles. The rays are reflected by the lattice planes of the monocrystal. An energy detector is only used to measure those radiation parts that interfere constructively. The lattice constant of the crystal is determined with the aid of the various orders of diffraction and the […]
Energy-dispersive measurements of K- and L-absorption edges
Principle Thin powder samples are subjected to polychromatic X-rays. The energy of the radiation that passes through the samples is analysed with the aid of a semiconductor detector and a multi-channel analyser. The energy of the corresponding absorption edges is determined and the resulting Moseley diagrams are used to determine the Rydberg frequency, the screening […]
Debye-Scherrer diffraction patterns with a cubic powder sample
PrincipleA cubic crystalline powder sample is irradiated with the radiation from a X-ray tube with a copper anode. A Geiger-Mueller counter tube is automatically swivelled to detect the radiation that is constructively reflected from the various lattice planes of the crystallites. The Bragg diagram is automatically recorded. A graphical evaluation procedure is used to assign […]
Debye-Scherrer diffraction patterns of powder samples with a tetragonal lattice structure
PrincipleA polycrystalline powder sample of lead dioxide is irradiated with the radiation from a X-ray tube with a copper anode. A Geiger-Mueller counter tube is automatically swivelled to detect the radiation that is constructively reflected from the various lattice planes of the crystallites. The Debye-Scherrer pattern is automatically recorded. The evaluation of the pattern not […]
Debye-Scherrer diffraction patterns of powder samples with a hexagonal lattice structure
Principle A polycrystalline powder sample of zinc is irradiated with the radiation from a X-ray tube with a copper anode. A Geiger-Mueller counter tube is automatically swivelled to detect the radiation that is constructively reflected from the various lattice planes of the crystallites. The Debye-Scherrer pattern is automatically recorded. The evaluation of the pattern not […]
Debye-Scherrer diffractions pattern of powder samples with a diamond structure (according to Bragg-Brentano)
PrinciplePolycrystalline powder samples, which crystallize in the three cubic Bravais types, simple, face-centered and body-centered, are irradiated with the radiation from a Roentgen tube with a copper anode. A swivelling Geiger-Mueller counter tube detects the radiation that is constructively reflected from the various lattice planes of the crystallites. The Bragg diagrams are automatically recorded. Their […]
Debye-Scherrer diffraction patterns of powder samples with three cubic Bravais lattices
Principle Polycrystalline powder samples, which crystallize in the three cubic Bravais types, simple, face-centered and body-centered, are irradiated with the radiation from a Roentgen tube with a copper anode. A swivelling Geiger-Mueller counter tube detects the radiation that is constructively reflected from the various lattice planes of the crystallites. The Bragg diagrams are automatically recorded. […]
X-ray investigation of crystal structures / Laue method with digital X-ray image sensor(XRIS)
Principle Laue diagrams are produced when monocrystals are irradiated with polychromatic X-rays. This method is primarily used for the determination of crystal symmetries and the orientation of crystals. When a LiF monocrystal is irradiated with polychromatic X-rays, a characteristic diffraction pattern results. This pattern is photographed with the digital X-ray sensor XRIS. Tasks The Laue […]
X-ray investigation of hexagonal crystal structures / Debye-Scherrer powder method
Principle A polycrystalline zirconium foil is irradiated with X-rays. The resulting Debye-Scherrer reflections are photographed and then evaluated. Tasks Take Debye-Scherrer photographs of the zirconium sample. Evaluate the Debye-Scherrer rings and assign them to the corresponding lattice planes. Determine the lattice constants of the sample material. Determine the number of atoms in a unit cell […]
X-ray investigation of crystal structures / Laue method
Principle Laue diagrams are produced when monocrystals are irradiated with polychromatic X-rays. This method is primarily used for the determination of crystal symmetries and the orientation of crystals. When a LiF monocrystal is irradiated with polychromatic X-rays, a characteristic diffraction pattern results. This pattern is photographed and then evaluated. Tasks The Laue diffraction of an […]
X-ray investigation of cubic crystal structures / Debye-Scherrer powder method
Principle When polycrystalline samples are irradiated with X-rays a characteristic diffraction pattern results. These Debye-Scherrer reflections are photographed and then evaluated. Tasks Debye-Scherrer photographs are to be taken of powdered samples of sodium chloride and caesium chloride. The Debye-Scherrer rings are to be evaluated and assigned to the corresponding lattice planes. The lattice constants of […]
Examination of the structure of NaCl monocrystals with different orientations
Principle The spectra of the X-rays that are reflected with various different orientations by NaCl monocrystals are analysed. The associated interplanar spacings are determined based on the Bragg angles of the characteristic lines. Tasks Determine the intensity of the X-rays that are reflected by the NaCl monocrystals with the orientations [100], [110] and [111] as […]
Hall effect in n- and p-germanium (PC)
Principle The resistivity and Hall voltage of a rectangular germanium sample are measured as a function of temperature and magnetic field. The band spacing, the specific conductivity, the type of charge carrier and the mobility of the charge carriers are determined from the measurements. Tasks The Hall voltage is measured at room temperature and constant […]
Hall effect in metals
Principle The Hall effect in thin zinc and copper foils is studied and the Hall coefficient determined. The effect of temperature on the Hall voltage is investigated. Tasks The Hall voltage is measured in thin copper and zinc foils. The Hall coefficient is determined from measurements of the current and the magnetic induction. The temperature […]
Beta spectroscopy
Principle The radiation of β-unstable atomic nuclei is selected on the basis of its pulses in a magnetic transverse field, using a diaphragm system. The relationship between coil current and particle energy is determined for calibration of the spectrometer and the decay energy of the β-transition is obtained in each case from the β–-spectra. Tasks […]
Semiconductor thermogenerator – Seebeck effect
Principle In a semi-conductor thermogenerator, the no-load voltage and the short-circuit current are measured as a function of the temperature difference. The internal resistance, the Seebeck coefficient and the efficiency are determined. Benefits Open design allows to fully understand function and applications Individual instruments for distinct functions (no “black box”) Key products of the experiment […]
Absorption spectra
PrincipleElectron shells of metal atoms in the gas phase can be elevated to an excited state by light. If light is passed through the metal vapour, various lines will be absent from its spectrum afterwards. These lines correspond to the energy levels of those electrons in the metal vapour which have been excited by the […]
Rutherford experiment with MCA
Principle The relationship between the angle of scattering and the rate of scattering of alpha-particles by gold foil is examined with a semiconductor detector. This detector has a detection probability of 1 for alpha-particles and virtually no zero effect, so that the number of pulses agrees exactly with the number of alpha-particles striking the detector. […]
Electron spin resonance
Principle With electron spin resonance (ESR) spectroscopy compounds having unpaired electrons can be studied. The physical background of ESR is similar to that of nuclear magnetic resonance (NMR), but with this technique electron spins are excited instead of spins of atomic nuclei. The g-factor of a DPPH (Diphenylpikrylhydrazyl) specimen and the halfwidth of the absorption line […]
Stern-Gerlach experiment
Principle A beam of potassium atoms generated in a hot furnace travels along a specific path in a magnetic two-wire field. Because of the magnetic moment of the potassium atoms, the non-homogeneity of the field applies a force at right angles to the direction of their motion. The potassium atoms are thereby deflected from their […]
Helium Neon laser, basic set
Principle The difference between spontaneous and stimulated emission of light is demonstrated. The beam propagation within the resonator cavity of a He-Ne laser and its divergence are determined, its stability criterion is checked and the relative output power of the laser is measured as a function of the tube’s position inside the resonator and of […]
K alpha doublet splitting of iron X-rays / fine structure
PrincipleThe polychromatic iron X-ray spectrum is to analyzed by means of a monocrystal. The energy of the characteristic lines is to be determined from the positions of the glancing angles for various orders of diffraction. The separation of the Ka doublet in higher order diffraction is to be examined. Tasks Record the intensity of the […]
K alpha double splitting of molybdenum X-rays / fine structure
Principle The polychromatic molybdenum X-ray spectrum is analyzed by means of a monocrystal. The energy of the characteristic lines is determined from the positions of the glancing angles at various orders of diffraction. The separation of the K a doublet in higher order diffraction is examined. Tasks Record the intensity of the X-rays emitted by the molybdenum […]
Characteristic X-rays of tungsten
Principle An X-ray tube with a tungsten anode generates X-radiation that is selected with the aid of a monocrystal as a function of the Bragg angle. A Geiger-Müller counter tube measures the intensity of the radiation. The glancing angles of the characteristic X-ray lines are then used to determine the energy. Tasks Record the intensity […]
Characteristic X-rays of iron
Principle Spectra of X-rays from an iron anode are to be analyzed by means of different monocrystals and the results plotted graphically. The energies of the characteristic lines are then to be determined from the positions of the glancing angles for the various orders of diffraction Tasks Record the intensity of the X-rays emitted by the […]
Characteristic X-rays of molybdenum
Principle Spectra of X-rays from a molybdenum anode are to be analyzed by means of different monocrystals and the results plotted graphically. The energies of the characteristic lines are then to be determined from the positions of the glancing angles for the various orders of diffraction. Tasks Record the intensity of the X-rays emitted by the […]
Characteristic X-rays of copper
Principle Spectra of X-rays from a copper anode are analyzed using different monocrystals and the results plotted graphically. The energies of the characteristic lines are then determined from the positions of the glancing angles for the various orders of diffraction. Tasks Record the intensity of the X-rays emitted by the copper anode as a function of the […]
K and L absorption edges of X-rays / Moseley’s law and the Rydberg constant
Principle Samples of various elements of different atomic numbers are irradiated with X-rays of a known spectral distribution. The energy of the transmitted intensities is analyzed using a monocrystal analyzer. Subsequently, the Rydberg constant and the screening constants are calculated from the energy of the absorption edges. Tasks Record the intensity of the X-rays emitted […]
Characteristic X-ray lines of different anode materials / Moseley’s law
Principle Moseley’s law describes the relationship between the energy of the Ka lines of characteristic X-ray spectra and the atomic number. In this experiment, the characteristic X-ray lines of various different anode materials are determined in order to verify Moseley’s law. Tasks Record the X-ray spectra of the three X-ray tubes. Determine the wavelengths and […]
X-ray fluorescence and Moseley’s law
Principle The irradiation of iodine, barium (sulfat), silver and tin with soft gamma-radiations gives rise to Ka radiations characteristics of these elements. The X-ray spectra are recorded with a gamma spectrometer consisting of a scintillation counter, a pulse height analyser and a recorder. After calibration of the spectrometer, the Rydberg constant is determined from the energies […]
Atomic spectra of two-electron system: He, Hg
Principle The spectral lines of He and Hg are examined by means of a diffraction grating. The wavelengths of the lines are determined from the geometrical arrangement and the diffraction grating constants. Tasks Determination of the wavelengths of the most intense spectral lines of He. Determination of the wavelengths of the most intense spectral lines […]
Fundamental principles of Nuclear Magnetic Resonance (NMR)
Principle The fundamental principles concerning the phenomenon of nuclear magnetic resonance (NMR) are demonstrated. Experiments are executed with a MRT training device giving the opportunity to investigate some small probes in the sample chamber. Investigations comprise the tuning of the system frequency to the Larmor frequency, the determination of the flip angle of the magnetisation vector, the […]
https://www.phywe.com/en/zeeman-effect-with-a-variable-magnetic-system.html
Principle The “Zeeman effect” is the splitting up of the spectral lines of atoms within a magnetic field. The simplest is the splitting up of one spectral line into three components called the “normal Zeeman effect”. In this experiment the normal Zeeman effect as well as the anomalous Zeeman effect are studied using a cadmium […]
Zeeman effect with electromagnet
Principle The “Zeeman effect” is the splitting up of the spectral lines of atoms within a magnetic field. The simplest is the splitting up of one spectral line into three components called the “normal Zeeman effect”. In this experiment the normal Zeeman effect as well as the anomalous Zeeman effect are studied using a cadmium […]
Planck’s “quantum of action” and photoelectric effect(line separation by interference filters)
PrincipleA photocell is illuminated with monochromatic light of different wavelengths from a filament lamp with interference filters. The maximum energy of the ejected electrons in the photo-cell depends only on the frequency of the incident light, and is independent of its intensity. The stopping voltage Uo at different light frequencies is determined by the U/I caracteristics of the […]
Diffraction at a slit and Heisenberg’s uncertainty principle
Principle The distribution of intensity in the Fraunhofer diffraction pattern of a slit is measured. The results are evaluated both from the wave pattern view point, by comparison with Kirchhoff’s diffraction formula, and from the quantum mechanics standpoint to confirm Heisenberg’s uncertainty principle. Benefits quantum mechanical versus wave theory viewpoints are discussed observing light transversing […]
Duane-Hunt displacement law and Planck’s “quantum of action”
Principle X-ray spectra are recorded as a function of the anode voltage. The short wavelength limit of the bremsspectrum is used to determine the agreement with the Duane-Hunt displacement law, and to determine Planck’s “quantum of action”. Tasks Record the intensity of the X-rays emitted by the copper anode at various anode voltages as a […]
Compton scattering of X-rays
PrincipleCompton scattering is to be achieved by directing an X-ray beam against a piece of plastic. The portions of the scattered X-rays at various angles is to be measured with a counter tube. Measurements are to be made with an absorber positioned in front of and behind the scatterer, so that the Compton wave length […]
Compton effect – energy-dispersive direct measurement
Principle Photons of the molybdenum Kα X-ray line are scattered at the quasi-free electrons of an acrylic glass cuboid. The energy of the scattered photons is determined in an angle-dependent manner with the aid of a swivelling semiconductor detector and a multi-channel analyser. Tasks Energy calibration of the multi-channel analyser with the aid of the two […]
Compton effect
PrincipleWhen photons are scattered on electrons, their momentum and energy gets changed. The energy of scattered gamma-radiation is measured as a function of the angle of scatter. The Compton wavelength is determined from the measured values. Tasks Calibrate the measuring set-up with the aid of a Cs-137 calibrating source (37 kBq) and a Na-22 source […]
Electron diffraction
Principle Fast electrons are diffracted from a polycrystalline layer of graphite: interference rings appear on a fluorescent screen. The interplanar spacing in graphite is determined from the diameter of the rings and the accelerating voltage. Tasks To measure the diameter of the two smallest diffraction rings at different anode voltages. To calculate the wavelength of […]
Electron spin resonance
Principle With electron spin resonance (ESR) spectroscopy compounds having unpaired electrons can be studied. The physical background of ESR is similar to that of nuclear magnetic resonance (NMR), but with this technique electron spins are excited instead of spins of atomic nuclei. The g-factor of a DPPH (Diphenylpikrylhydrazyl) specimen and the halfwidth of the absorption line […]
Magnetic Resonance Imaging (MRI) II
Principle The aim of these experiments is to show how the spin echo technique can be used to generate 2D MR images of a slice of a well-defined thickness, orientation, and size (Localized Spin Echo 2D). These parameters determine the so-called “field of view” (FOV) of the MR image. We will introduce a method that […]
Magnetic Resonance Imaging (MRI) I
Principle The basic principles of 2D MR imaging are demonstrated with two methods relying on two different gradient techniques. Experiments are executed with a MRT training device giving the opportunity to investigate some small probes in the sample chamber. Device control is done with the provided software. Investigations comprise the generation of a two-dimensional cross-section […]
Spatial encoding in Nuclear Magnetic Resonance
Principle It should be demonstrated how spatial encoding does work in the MR technology. Experiments are executed with a MRT training device giving the opportunity ton investigate some small probes in the sample chamber. Device control is done with the provided software. Investigations comprise the generation of a 1D spatial encoding procedure via an additional […]
Relaxation times in Nuclear Magnetic Resonance
PrincipleThe principles of relaxation processes using the MR technology are demonstrated. Experiments are executed with the MRT training device giving the opportunity to investigate some small probes in the sample chamber. Device control is done with the provided software. Investigations comprise the estimation of the relaxation time T1 which is a measure of time for reestablishing […]
Stern-Gerlach experiment
Principle A beam of potassium atoms generated in a hot furnace travels along a specific path in a magnetic two-wire field. Because of the magnetic moment of the potassium atoms, the non-homogeneity of the field applies a force at right angles to the direction of their motion. The potassium atoms are thereby deflected from their […]
Franck-Hertz experiment with a Ne-tube
Principle Electrons are accelerated in a tube filled with neon vapour. The excitation energy of neon is determined from the distance between the equidistant minima of the electron current in a variable opposing electric field. Tasks To record the counter current strength I in a Franck-Hertz tube as a function of the anode voltage U. To determine the […]
Franck-Hertz experiment with a Hg-tube
Principle Electrons are accelerated in a tube filled with mercury vapour. The excitation energy of mercury is determined from the distance between the equidistant minima of the electron current in a variable opposing electric field. Benefits Experience the essence of the Nobel Price: Franck, Hertz (1925) Classical Version with Mercury (Hg) One operating unit for […]
Specific charge of the electron – e/m
PrincipleElectrons are accelerated in an electric field and enter a magnetic field at right angles to the direction of motion. The specific charge of the electron is determined from the accelerating voltage, the magnetic field strength and the radius of the electron orbit. Tasks Determination of the specific charge of the electron (e/m0) from the […]
Elementary charge and Millikan experiment
Principle Charged oil droplets subjected to an electric field and to gravity between the plates of a capacitor are accelerated by application of a voltage. The elementary charge is determined from the velocities in the direction of gravity and in the opposite direction. Tasks Measurement of the rise and fall times of oil droplets with […]
Quantum eraser with the Mach-Zehnder interferometer
Principle A Mach-Zehnder-interferometer is illuminated with a laser beam. Circular interference fringes appear on the screens behind the interferometer. If polarisation filters with opposite polarisation planes are placed in the two interferometer paths the interference patterns disappear. Placing another polariser before one of the screens causes the pattern to reappear. Electromagnetic radiation can be described […]