Item no.: P2522215 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
Item no.: P2538000 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
Item no.: P2530111 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
Item no.: P2540101 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
Item no.: P2510700 Principle The spectral lines of hydrogen and mercury are examined by means of a diffraction grating. The known spectral lines of Hg are used to determine the grating constant. The wave lengths of the visible lines of the Balmer series of H are measured. Tasks Determination of the diffraction grating constant by
Item no.: P2511200 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
Item no.: P2510311 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. Tasks To record the countercurrent strength Ι in a Franck-Hertz tube as a function of the anode voltage U. To
Item no.: P2510200 Principle Electrons 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
Item no.: P2250105 Principle Monochromatic light impinges on amica plate, perpenicularly to its optical axis. If the thickness of the plate is adequate (lambda/4 plate), a phase shift of 90° occurs between the ordinary and the extraordinary beam when the latter leaves the crystal. The polarisation of exiting light is examined for different angles between
Item no.: P2220705 Principle Light is caused to interfere by means of a beam splitter and two mirrors according to Michelson’s set up. Substituting the air in a measurement cuvette located in one of the interferometer arms by CO2 gas allows to determine the index of refraction of CO2. Tasks A Michelson Interferometer is set up