11 Nuclear Physics - Radioactivity 11.3 Alpha Particles - Energy - Rutherford Experiment
P2522215
Fine structure of the alpha spectrum of Am-241 with Multi Channel Analyser (MCA) / alpha spectroscopy
Measured Alpha-spectrum of Am-241.
Principle The alpha-spectrum of an open 241Am-emitter is measured with a semiconductor a-detector, maximum use being made in this case of the resolution capacity of the pulse height analyzer. Use is made for this purpose of the "Zoom" function, which is an additional amplification stage having in the effect that only that proportion of the pulses exceeding the threshold voltage of 5 V undergoes further processing. The pulse peaks above this threshold are amplified 5 times and restricted to a maximum of 10 V.
Pre-amplifier f.alpha detector Alpha and Photodetector measure Software multi channel analyser Screened cable, BNC, l 750 mm Vacuum tube, NBR, 6/15 mm, 1 m
09100-10 09099-00 14452-61 07542-11 39289-00
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Container for nuclear physical experiments
Tasks 1. The spectrum of an open 241Am-emitter is recorded with the xyt recorder at the maximum resolution capacity of the measurement layout, using automatic window movement. The energy of the two peaks preceding the principal peak is calculated. The principal peak, corresponding to a particle energy of 5.486 MeV, is used for calibration purposes. 2. The resolution capacity of the measurement layout is measured from the half-life width of the principal peak. Function and Applications
What you can learn about ▪ ▪ ▪ ▪ ▪
Energy level diagram (decay diagram) Transition probability Excited nuclear states γ-emission Connection between the fine structure of the α-spectrum and the accompanying γ-spectrum
Main articles Multi channel analyser Container f.nuclear phys.expts. Radioactive source Am-241, 3.7 kBq Diaphragm pump, two stage, 220V Vacuum gauge DVR 2, 1 ... 1000 hPa, 1 hPa resolution
13727-99 09103-00 09090-03 08163-93
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Container for nuclear physical experiments. Equipment and technical data ▪ Cylindrical glasstube, 75 mm diam., 400 mm long, with a printed on scale 0 to 28 cm and metal flanges at its end. ▪ Removable by knurled head screws. ▪ One flange with vacuum tight centrally fitted bearing for a.push-rod for radioactive source adaption. ▪ Second flange with adaptors for vacuum system and detector. 09103-00