$IAEA_INDEX: 112 // IAEA website: www-nds.iaea.org/phsp/photon/ $TITLE: Siemens PRIMUS 6MV photon beam 20.0 x 20.0 cm2 field $FILE_TYPE: 0 $CHECKSUM: 915433546 $RECORD_CONTENTS: 1 // X is stored ? 1 // Y is stored ? 0 // Z is stored ? 1 // U is stored ? 1 // V is stored ? 1 // W is stored ? 1 // Weight is stored ? 0 // Extra floats stored ? 1 // Extra longs stored ? 2 // LATCH EGS variable stored in the extralong array [ 0] $RECORD_CONSTANT: 90.0000 // Constant Z $RECORD_LENGTH: 29 $BYTE_ORDER: 1234 $ORIG_HISTORIES: 2999999 $PARTICLES: 31566674 $PHOTONS: 31396182 $ELECTRONS: 166170 $POSITRONS: 4322 $TRANSPORT_PARAMETERS: Photon transport cutoff(MeV)->0.010 Pair angular sampling->KM Bound Compton scattering->ON Rayleigh scattering->OFF Atomic relaxations->OFF Photoelectron angular sampling->ON Electron transport cutoff(MeV)->0.001 Bremsstrahlung cross sections->NIST Bremsstrahlung angular sampling->KM Spin effects->On Electron Impact Ionization->Off Maxium electron step in cm (SMAX)->0.1000E+11 Maximum fractional energy loss/step (ESTEPE)->0.2500 Maximum 1st elastic moment/step (XIMAX)->0.5000 Boundary crossing algorithm->EXACT Skin-depth for boundary crossing (MFP)->3.000 Electron-step algorithm->PRESTA-II $MACHINE_TYPE: SIEMENS PRIMUS 6MV $MONTE_CARLO_CODE_VERSION: version V1 of BEAMnrc (Rev 1.78 last edited 2004-01-12 11:44:06-05) $GLOBAL_PHOTON_ENERGY_CUTOFF: 0.010 $GLOBAL_PARTICLE_ENERGY_CUTOFF: 0.001 $COORDINATE_SYSTEM_DESCRIPTION: Cartesian Right-Handed, origin: z=0->bottom of the target, x=y=0->central position of the target, z-axis parallel to beam direction, incresing towards the patient, x-axis parallel to MLC leaf movement // OPTIONAL INFORMATION $BEAM_NAME: 6MV photon beam $FIELD_SIZE: 20.0 cm x 20.0 cm $NOMINAL_SSD: 100 cm $MC_INPUT_FILENAME: $VARIANCE_REDUCTION_TECHNIQUES: Bremsstrahlung splitting->OFF Range rejection switch->ON (IREJCT_GLOBAL = 2 => ECUTRR = ECUT(region) , ESAVE = 2.0 MeV) $INITIAL_SOURCE_DESCRIPTION: FULL PHASE SPACE INPUT FOR EACH INCIDENT PARTICLE SOURCE INCIDENT ON FRONT FACE, Z->9.97 cm SOURCE INCIDENT ON MODULE ICM->1 Total # of particles in the file->47347902 # of photons in the file->47346956 Maximum energy of particles->7.077 MeV Minimum energy of electrons->0.189 MeV # of particles incident from original source->3000000.0 # of times each particle will be recycled->0 ORIGINAL SOURCE MEAN ENERGY->6.0 MeV ORIGINAL SOURCE SPATIAL FWHM->0.10 cm $PUBLISHED_REFERENCE: 1->Automatic determination of primary electron beam parameters in Monte Carlo simulation. 2007, Med. Phys. 34, 1076-1084 2->A new method for output factor determination in MLC shaped narrow beams. Physica Medica 23 (2007) 58-66 3->Monte Carlo correction factors in small field absolute dosimetry: a feasibility study (Unpublished, available from the phsp web site) $AUTHORS: J PENA, D M GONZALEZ-CASTANO, F SANCHEZ-DOBLADO, G HARTMANN $INSTITUTION: UNIVERSIDAD DE SANTIAGO DE COMPOSTELA (SPAIN) $LINK_VALIDATION: $ADDITIONAL_NOTES: This is IAEA header as defined in the technical report IAEA(NDS)-0484, Vienna, 2006 $STATISTICAL_INFORMATION_PARTICLES: // Weight Wmin Wmax Emin Emax Particle 24886.8 1.779E-34 0.9307 1.572 0.01003 7.077 PHOTONS 108.177 1.411E-23 0.9189 1.458 0.189 6.431 ELECTRONS 4.51389 3.029E-17 0.922 1.665 0.1894 5.078 POSITRONS $STATISTICAL_INFORMATION_GEOMETRY: -30 29.9996 -29.9997 29.9997