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GEANT4-DNA New physics models …from cell to DNA Christophe Champion FKPPL Workshop Seoul March 8-10, 2011 From water to DNA: The classical Trajectory Monte Carlo - Classical Over Barrier model (CTMC-COB) ZP Y vP X RP b zP Z ZT re1 Input dynamical data : e1 Each simulation starts and stops at large internuclear distance (≈100 a.u.) the projectile velocity (VP) the impact parameter (b) the initial conditions for the target The classical Trajectory Monte Carlo - Classical Over Barrier model (CTMC-COB) The molecular binding energies The classical Trajectory Monte Carlo - Classical Over Barrier model (CTMC-COB) General features of the classical models Movements of the particles described by Newton laws Initial targets information = the knowledge of the binding energies Classical criteria for describing the ionizing processes Total cross sections: i 2 bmax P (b)bdb i 0 N i b Pi (b) N tot b The classical Trajectory Monte Carlo - Classical Over Barrier model (CTMC-COB) COB (Classical Over Barrier) criteria RR Target Projectile e5 Projectile Target Target e1 Potential over barrier Bound target electrons (c) (b) (a) Molecular electron Potentielover overbarrier barrier Potential e2 e4 Projectile R=R1 e11 ee2 2 eee333 Target electrons e4 ee45 e5 Captured electrons Target electrons The classical Trajectory Monte Carlo - Classical Over Barrier model (CTMC-COB) COB (Classical Over Barrier) criteria The Classical Trajectory Monte Carlo - Classical Over Barrier model (CTMC-COB) COB (Classical Over Barrier) criteria R Projectile Target Potential over barrier e1 e2 Target electrons Potential seen by the bound electron e1: e4 R=R1 Projectile Molecular electron Target e1 e2 Potential over barrier VP ZP and re1 RP Target electrons (b) R Target Potentiel over barrier e2 e4 Projectile (c) at the beginning of the simulation e1 e3 e5 Bound target electrons where e3 e4 e5 VT 1 re1 RT RT 0 e5 (a) Vtot (re1 ) VP (re1 RP ) VT (re1 RT ) where e3 Captured electrons The classical Trajectory Monte Carlo - Classical Over Barrier model (CTMC-COB) Propagation of the system At each step Δt (≈10-2 a.u.) COB and d conditions are tested: At each time T and/or e-) 1 for each involved particleZ Pi (i = ZP, 1 Z P step ZtT and T 2 V r1 , r2 V (r1 ) r a r12 a r R a r1 a 2 r1 R a 2 ˆ ˆ ˆ r x i y j z k For the nexti time i step :i t’ = t i + Δt ri vt.viv iˆ v ˆj v kˆ i xi yi zi ri ri ri vi F t.aim a iˆ a ˆj a kˆ vi vi vi i i x y z i i i The classical Trajectory Monte Carlo - Classical Over Barrier model (CTMC-COB) Conditions and criteria of the final state E i P (T ) 1 2 vi vP (T ) 2 Z P (T ) 1 2 j i ri r j ri RP (T ) kinetic energy of the electron relatively to the target or the projectile potential energy of the electron relatively to the target or the projectile if EPi 0 the electron i is captured if ETi 0 the electron i remains bound to the target if EPi 0 and ETi 0 the electron i is ejected The classical Trajectory Monte Carlo - Classical Over Barrier model (CTMC-COB) Total cross sections for the main ionizing processes induced by charged particles Abbas et al., Phys. Med. Biol. 53, N1-N11 (2008) Lekadir et al., NIM B 267, 1011-1014 (2009) Lekadir et al., Phys. Rev. A 79, 062710 (2009) From water to DNA: Quantum mechanical approaches: Coulomb Born approximation (CB1) Continuum Distorted Wave – Eikonal Initial State (CDW-EIS) Champion et al., Phys. Med. Biol. 55, 6053-6067 (2010) Target description LCAO: Linear Combination of Atomic Orbitals Bernahrdt and Paretzke (Int. J. Mass Spectrom. 599 (2003)) 3 3 N N d d j ( 3 ) ( , , E ) ( , , E ) s e e j s e e d d dE d d dE j 1 j 1 s e e s e e 3 ( 3 ) ( , , E ) g . . ( , , E ) i i at , i s e e ( 3 ) j se e i at(3,)i ( s , e , Ee ) Ta ,b i 2 Z Z P P T ( R ) . ( r ) ( R ) . ( r ) a , b i , b i , b i , a i , a i R R r Quantum mechanical /classical approaches: CB1, CDW-EIS / CTMC-COB Ionization of DNA bases impacted by light ions Abbas et al., Phys. Med. Biol. 53, N1-N11 (2008) Lekadir et al., NIM B 267, 1011-1014 (2009) Lekadir et al., Phys. Rev. A 79, 062710 (2009) Protons 2+ H + Cytosine 2 10 2 CDW-EIS CBA CTMC-COB exp -1 + + H + Guanine H + Thymine 10 10 2 1 1 CBA CDW-EIS CTMC-COB 10 10 0 2+ 2+ He + Thymine 10 10 10 He + Guanine 2 10 10 1 10 2 10 3 10 4 10 15 10 2 10 3 10 Incident proton energy (keV/amu) 4 10 5 2 10 1 CBA CDW-EIS CTMC-COB 10 0 6+ 6+ C + Guanine C + Thymine 10 3 10 2 10 1 10 0 1 0 -1 10 -16 10 -16 Total cross sections (10 10 0 3 2 cm ) 2 -16 Total Cross Sections (10 10 10 C + Cytosine 2 1 cm ) 10 6+ C + Adenine He + Cytosine Total cross sections (10 cm ) 10 6+ 2+ He + Adenine + + H + Adenine Carbon ions C6+ a-particles 0 10 1 10 2 10 3 10 1 10 2 10 3 Incident ion energy (keV/amu) 10 4 10 1 10 2 10 3 10 4 10 15 10 2 10 3 Incident ion energy (keV/amu) 10 4 10 5 Quantum mechanical approaches: Continuum Distorted Wave – Eikonal Initial State (CDW-EIS) Capture on DNA bases impacted by light ions Protons 10 -13 10 -14 10 -15 10 -16 10 -17 10 -18 10 -19 H + Adenine H + Cytosine 10 -20 10 -21 10 -22 10 -23 10 -13 10 -14 10 -15 10 -16 10 -17 10 -18 10 -19 10 -20 10 -21 10 -22 10 -23 10 -12 10 -13 10 -14 10 -15 10 -16 10 -17 10 -18 10 -19 10 -20 10 -21 10 -22 10 -23 10 -24 10 -25 -11 10 -12 10 -13 10 -14 10 -15 10 -16 10 -17 10 -18 10 -19 10 -20 10 -21 10 -22 10 -23 10 -24 10 -25 2 Total cross sections (cm ) 2 10 CTMC-COB CDW2 (CNDObis) (n=1 + n=2) CDW2 (CNDObis) (n=1) CDW2 (CNDObis) (n=2) + 2 -11 10 + H + Guanine 1 10 2 10 3 Incident energy (keV/amu) 6+ C 6+ + Adenine C + Cytosine + experimental Total cross sections (cm ) 10 -12 + Total cross sections (cm ) Carbon ions C6+ H + Thymine 10 1 2 10 10 3 Incident energy (keV/amu) 4 10 CTMC-COB CDW CDW CDW CDW CDW (n=1+n=2+n=3+n=4) (n=1) (n=2) (n=3) (n=4) 6+ C 1 10 2 10 + Guanine 3 10 C 10 1 6+ + Thymine 2 10 Incident ion energy (keV/amu) 3 10 4 10 DNA versus liquid water: GEANT4 simulations Results DNA 10 bp target Nucleosome target An increase of the mean energy value of energy deposits of the order of 25% for the 10 base pairs target and 25% for the nucleosome target