Semiempirical MonteCarlo for FAZIA

1. Semiempirical MonteCarlo for FAZIA Napoli, 3-5 October, 2007 Silvia Piantelli and Giovanni Casini Giovanni Casini INFN Florence

2. Some Reactions of FAZIA interest At Bologna (dec 2006) we decided to start with some systems to study physics and spurious effects • NiNi at 10 and 40 AMeV • SnSn at 40 AMeV • NiSn at 10 AMeV • Kr+Ca at 5AMeV

3. Deep inelastic and Fusion Reactions • We started with NiNi at 10AMeV • At the SPIRAL2 and SPES energies, dominant mechanisms are Deep inelastic collisions (DIC) and Fusion reactions (FR): we cannot disregard them! • For the moment the DIC are better developed and most 'results' concern these ones, till now • We also started some FR simulations • We think to also include some pre-equilibrium effect (i.e. emission before separation in PLF-TLF for DIC and emission before evaporation or fission for FR

4. MCARLO tree Random Generation of l (hbar) from l0 and lmax where lmax=lgrazing: triangular distribution • Decision if the event is a DIC or a Fusion FUS event (on the basis of l )‏ • If DIC: • Random extraction of TKE within the range Vcb to Ecm • Sorting of the mass A (and thus the charge Z) of the PLF and TLF (primary); • Sorting of the CM-angles of the PLF and TLF (primary); • A recipe for the Excitation energy sharing; • A recipe for the Angular momentum sharing;

5. MCarlo: DIC Wilczynski plot DIFFUSION PLOT These primary correlations can/must be tuned for the various reactions. The literature gives some parametrisations

6. MCarlo: DIC DIFFUSION PLOT The excitation energy can be shared, in a given event, following (old) experimental results. The general trend is: equal energy sharing for large b; tendency to equal temperature at small b. In this picture TQP=TQT

7. MCarlo: FR If l<lcrit we can produce (complete) fusion. We have to check the amount of DIC vs. FR basing on the literature. The Compound nucleus gets the whole excitation energy and travels at 0deg in the LAB with the CM energy. The CN can decay via evaporation or via fission (to be implemented)‏ The evap vs. fission rate will be regulated basing on the literature. The same for the mass asymmetry of Fission Fragments.

8. DECAY The PLF, TLF or the CN are excited. The decay occurs via light particle and IMF evaporation with a parametrisation based on GEMINI as a function of the excited nucleus parameter set (A,Z,E*,l) One can also select the fission channel; the parameters of this step (mass asymmetry, out-plane, in-plane) are suitably tuned The kinematic quantities are written for all charged particles

9. Geometry (largely inspired from M.Gautier geometry) • trapezoidal detectors with active area r dθ=20mm and r sin θmed dφ = 20 mm • 1 sphere portion at r=1200mm for θ=0.5-22.5; Δθ=1.1, active 0.96 (1286 detectors, 20 rings) • 1 sphere portion at r=1000mm for θ=22.5-43; Δθ=1.3, active 1.15 (2385 detectors, 16 rings) • 1 sphere portion at r=700mm for θ=43-90; Δθ=1.8, active 1.64 (4631 detectors, 26 rings) • 1 sphere portion at r=400mm for θ=90-170; Δθ=3.15, active 2.87 (1044 detectors, 26 rings) • TOTAL= 10346 detectors, 88 rings • The active region covers Ω/4π=81%

10. Geometry θcosφ θcosφ θsinφ θsinφ

11. In the simulation.... θcosφ θsinφ

12. Efficiency • target thickness 0.238 μg/cm2 • 0.1μm of Si of entrance dead layer • first Si detector: 300 μm thick; second Si detector: 700 μm thick • Tof resolution: σdetector=(-0.3*Epart+3.3)ns; σbeam = 800ps • Energy straggling: σBohr=(0.1569*Z2*Zsi*thick(μg/cm2)/AsiMeV • Energy resolution: σelectronic=0.2MeV; σdetector=1.15 10-3 *Elost MeV • if a particle punches through the first Si, E=ΔE+Eres; the particle is identified in Z and A (if Z<15) from ΔE-Eres; if Z>15, A is given from E and ToF • if a particle is stopped in the first Si, if it punches through the first 30 μm of Si, it is identified in Z (from the pulse shape technique), A is given from E-ToF; if it does not punches through the first 30 μm of Si, A is given from E-ToF and Z=A/2 • Hp: no PHD

13. true A=58 (58Ni+58Ni 10AMeV) TLF PLF Neither the PLF nor the TLF punch through the first Si: A is given from E-Tof

14. A from E-tof (stopped particles)

15. Punching-through particles

16. 58Ni+58Ni 10AMeV DIC FAZIA detected (exp-equivalent) primary 4π

17. 58Ni+58Ni 10AMeV DIC FAZIA detected (exp-equivalent) after evaporation 4π

18. 58Ni+58Ni 10AMeV DIC (other parametrization) primary 4π FAZIA detected (exp-equivalent)

19. 58Ni+58Ni 10AMeV DIC (other parametrization) FAZIA detected (exp-equivalent) after evaporation 4π

20. 58Ni+58Ni 10AMeV DIC: PLF evaporation warning 1: MC original source of particles (not reconstructed) warning 2: MC original charge for particles (not reconstructed)

21. 58Ni+58Ni 10AMeV DIC: TLF evaporation warning 1: MC original source of particles (not reconstructed) warning 2: MC original charge for particles (not reconstructed)

22. 58Ni+58Ni 10AMeV DIC particle multiplicities 4π 10 10 10 10 10 10 10 10 c z>6 c z>6 geometry + efficiency

23. 58Ni+58Ni 10AMeV Fusion (first attempt) θ lab A E lab primary after evap. + geometry + efficiency