Principle

The alpha-spectrum of an open 241-Am-emitter is measured with a semiconductor a-detector. In connection with a multi channel analyzer the main parts of the spectrum are investigated.

Benefits

• Alpha spectroscopy of the fine structure of alpha emitting Americium to understand the technique within a practical course
• The combination of multichannel analyzer (MCA), preamplifier and alpha detector leads to precise results.
• Transparent glass container with perfect visibility of the whole setup and good vacuum conditions, used in several experiments

Tasks

1. The spectrum of an uncovered 241-Am-emitter is recorded with the multi channel analyzer. The energies of the two peaks preceding the principal peak are 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.

Learning objectives

• 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