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

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

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

MCARLO tree Random Generation of l (hbar) from l 0 and l max where l max =l grazing : 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 V cb to E cm 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;

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

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 T QP =T QT

MCarlo: FR If l<l crit 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.

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

Geometry (largely inspired from M.Gautier geometry) trapezoidal detectors with active area r dθ=20mm and r sin θ med dφ = 20 mm 1 sphere portion at r=1200mm for θ= ; Δθ=1.1, active 0.96 (1286 detectors, 20 rings) 1 sphere portion at r=1000mm for θ= ; 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= detectors, 88 rings The active region covers Ω/4π=81%

Geometry θsinφ θcosφ θsinφ θcosφ

In the simulation.... θsinφ θcosφ

Efficiency target thickness μg/cm 2 0.1μm of Si of entrance dead layer first Si detector: 300 μm thick; second Si detector: 700 μm thick Tof resolution: σ detector =(-0.3*Epart+3.3)ns; σ beam = 800ps Energy straggling: σ Bohr =(0.1569*Z 2 *Z si *thick(μg/cm 2 )/A si MeV Energy resolution: σ electronic =0.2MeV; σ detector = *Elost MeV if a particle punches through the first Si, E=ΔE+Eres; the particle is identified in Z and A (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

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

A from E-tof (stopped particles)

Punching-through particles

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

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

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

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

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

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

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

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