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Download DPASS version 21.06 from 17 February 2020

bpeak is a list of heights and positions of the Bragg peak for 92x92 extracted from PASS output by Andreas Schinner and Peter Sigmund.

Download bpeak

Applications of the PASS Stopping Code (pdf)

PASS bibliography (pdf)


Save the files DPASS.exe and DPASS_DB.dat in a directory of your choice.

The code delivers stopping cross sections in charge equilibrium for projectile ions and target atoms from Hydrogen to Uranium over a chosen energy range within lower and upper limits 0.001 and 1000 MeV/u, respectively, in units of 10-15eVcm2 or MeVcm2/mg or eV/nm.

Running in direct mode

After opening the program, specify the atomic numbers of the projectile ion and the target, the desired energy range and number of points and the desired output units.

The option "raw data" delivers a logarithmic mesh of 100 data points over the interval from 0.001 to 1000 MeV/u. The option "spline data" allows you to apply your own choice of grid.

Running in batch mode

For running DPASS in batch mode, use the file DPASS.job. Find explanations in the file DPASS.pdf.

For the PASS code and the underlying theory we refer primarily to:

  • P. Sigmund & A. Schinner, Binary stopping theory for swift heavy ions, Eur. Phys. J. D 12, 425 (2000)
  • P. Sigmund & A. Schinner, Binary theory of electronic stopping, Nucl. Instrum. Methods B 195, 64 (2000)
  • Stopping of ions heavier than Helium, ICRU Report 73, Oxford University Press (2005)
  • Expanded  PASS stopping code, Nucl. Instrum. Methods B 460, 19 (2019)

Output from DPASS differs in several respects from the tables in ICRU Report 73:

  1. Data are offered for 92 elements.
  2. The allowed energy range has been expanded down to 0.001 MeV/u.
  3. Data for compounds are not yet incorporated but are reserved for a future update.
  4. Version 21.06 differs from the previous version in the following features:
    a) The valence shell has been treated as a free electron gas, as was done previously in ICRU Report 73. As in ICRU 73 this has been assumed to be a classical electron gas with the exception of proton data, where the Lindhard (1954) formula has been applied.
    b) PASS has two options for the electron configuration in a partially ionized projectile ion, bottom-up or `distributed'. In the latter version, projectile electrons are distributed over all states that are occuupied in the neutral atom.
    The `distributed' option was employed in ICRU73, whereas DPASS 2.05 was based on the bottom-up version. DPASS 21.06 is now based on the 'distributed' option. This proves to better describe the energy range around the Bragg peak.
  5. Unlike in ICRU73, data on compount targets have not bee incorporated in DPASS.

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Last Updated 10.08.2023