Supplemental Material: Study of radiation protection for the BELLA A-Cave

General description

Compressed archive containing the macro files and the scripts to run and analyze the results of the simulations of dose deposition in the BELLA A-Cave.

The Geant4 scripts contain the parameters of the initial beam and of the computational mesh where the dose equivalent is deposited, the python scripts extract the data from the resulting OpenPMD files.

The scripts include two possible configurations of shielding (Configuration 1 and Configuration 2) and the two initial beams investigated: a "realistic" distribution and an idealized 8 MeV monochromatic beam that represent the maximum point operationally achievable.

Configurations

Configuration 1:

It includes the following permanent shielding

Wall: the Cave A concrete walls, along with wall penetrations towards Cave B. All walls of Cave A are made of 36” thick concrete, except for the roof, the east wall and the entrance compartment walls which have a thickness of 24”. The penetrations for the beamline (from 1 to 3) and penetrations for the services (service penetrations in north, south, and east walls) are included in the simulations.

Pb1 and Pb2: 8” thick Pb shielding filling the two wall penetrations towards Cave B which are closest to the Cave A interaction chamber.

Pb3: A Pb plate (10” width, 10” height, 1” thickness) positioned at the exit of the interaction chamber, perpendicular to the beam axis. The plate has a square hole (4 cm side) centered at the position of the electron beam axis. 

Pb4: A Pb plate (20” width, 20” height, 1” thickness) placed at the west wall of Cave A, centered at the position of the electron beam axis.

SS1 and SS2:  stainless steel plates (2” thickness, 6” width, 2’ height) placed on both sides of the east wall, near the edges of penetration 3. The plates cover 3” of the window and 3” of the wall on both sides. The height of the plates is equal to the height of the opening.

Configuration 2:

In addition to the permanent shielding from Configuration 1, a tungsten (W) X-ray converter (0.5” width, 0.5” height, 2 mm thickness) is placed 3 cm downstream from the electron beam source. A 1”-wide and 4 cm long Pb shielding around the converter is considered.

Description of the archive

The archive is structure as follows

inputs_and_macros
├── Configuration_1__8MeV
│ ├── input.mac
│ ├── plot_dose_1_100_mrem_per_hour.py
│ └── print_dose_values.py
├── Configuration_1__exp_distribution
│ ├── input.mac
│ ├── khz_energy.dat
│ ├── plot_dose_1_100_mrem_per_hour.py
│ └── print_dose_values.py
├── Configuration_2__8MeV
│ ├── input.mac
│ ├── plot_dose_1_100_mrem_per_hour.py
│ └── print_dose_values.py
└── Configuration_2__exp_distribution
├── input.mac
├── khz_energy.dat
├── plot_dose_1_100_mrem_per_hour.py
└── print_dose_values.py