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Stopping power measurements of heavy ions over a wide range of energy

EMSL Project ID


The passage of charged particles through matter continues to be a subject of great interest
and importance to atomic and nuclear physics. Also, ion interaction in matter is crucial for
development of new radiation detector materials with high resolution. Moreover, many
applications, like ion beam analysis, relies on energy loss of ions where stopping power
determines absolute depth scales. In fundamental nuclear physics research, stopping power
of Au or Pb (generally used as backing) plays an important role for measuring picosecond
nuclear lifetimes with the Doppler Shift Attenuation Method (DSAM) for measuring pico
second nuclear lifetimes [1]. In all of cases, precision of the results are limited by accuracy
of stopping power used in the analysis.
From the theoretical viewpoint, stopping of swift hydrogen and helium ions in matter is
well described by the Bethe theory [2]. But the situation is completely dierent for heavy
ions slowing down at intermediate and low velocities, where both theoretical and semi-
empirical predictions can have large uncertainties. At those energies many processes like
electronic excitation and ionization of the atoms of matter contributes for stopping. A task
of arriving at a reliable scheme for predicting stopping powers is by no means straightforward
and future improvements in theories demand accurate experimental data.

Project Details

Project type
Exploratory Research
Start Date
End Date


Principal Investigator

Roberto Linares
Universidade de Sao Paulo

Team Members

Yanwen Zhang
Oak Ridge National Laboratory