[fluka-discuss]: Dose Scoring

From: Yuri Simeonov <yuri.simeonov_at_gmail.com>
Date: Tue, 20 Mar 2018 14:27:23 +0100

Dear Fluka experts,

We measured the 3D dose distribution from a scanned 5x5 cm2 field proton
beam using an in-house built binary "Range Shifter" and a 2D PTW dose
chamber array. The range shifter consists of many precisely cut PMMA
plates of different
thicknesses and was used as a water phantom substitute. These plates can be
moved quickly and independently in and out of the beam. By combining
different
plates, we can simulate different water equivalent depths. A scematic
figure of the RangeShifter is attached.
The dose was measured continuously by the 2D array (integration mode). In
order to reconstruct a 3D dose distribution from the single integrated dose
measurement, the time frame of the dose measurement was synchronised with
the time frame of the range shifter movements and the dose was "divided" in
many 2D slices, corresponding to the different water depths.
Due to a variaty of reasons, we would like to reproduce this measurement
setup in FLUKA, instead of simply simulating it in a water phantom. The
idea is to use the source.f routine (which we anyway use for raster
scanning) in combination with the *"SETBDY * " command. For example, we
want to simulate 10 depths (resp. 10 different range shifter
configurations) with 1000 primaries. After a stack of 100/200/300...
particles, the thickness and position of a single slab body will be changed
according to the original Range Shifter sequence.

The dose will be scored in e.g. 1mm water slice (one bin in beam
direction!), representing the real 2D Dose array. This way, at the end of
the simulation we will obtain dose distribution integrated over all depths.

Is there a way to reconstruct this integrated 2D dose to a 3D distribution,
i.e. to separate the contribution from each different Range Shifter depth?

Regards
Yuri



__________________________________________________________________________
You can manage unsubscription from this mailing list at https://www.fluka.org/fluka.php?id=acc_info

RangeShifterSetup.jpg
(image/jpeg attachment: RangeShifterSetup.jpg)

Received on Tue Mar 20 2018 - 15:57:57 CET

This archive was generated by hypermail 2.3.0 : Tue Mar 20 2018 - 16:27:28 CET