GAMMA-PARTICLE ARRAY FOR DIRECT REACTION STUDIES SIMULATIONS

Detection challenges for (d,p) reactions 78 Ni(d,p) MeV/u A Challenges: Kinematics compression ->Ep good resolution States separated by 1 MeV ->~200 keV in Ep Covers large range in θ _lab(deg) ->4pi ang cover Deposit of low Energy->Threshold problems Doppler Broadening Measurements->Observables Ep and/or E  ->Ex θ p -> d σ/d  -> (l, SF) θ _lab(deg) Energy (MeV)

PHYSICS CASE : DIRECT REACTION STUDIES Key experiments: Mapping of single-particle energies using transfer reactions 78 Ni(d,p) MeV/u 132 Sn(d,p) MeV/u Reactions : Elastic and inelastic scattering Transfer reactions A SUB-TASK: SINGLE-PARTICLES and COLLECTIVE PROPERTIES Integrated particle and gamma detection system : Direct reactions studies

132 Sn(d,p) AMeV Particle array (Simulations)

PARTICLE ARRAY: Simple Geometry Distance to (0,0,0) = 5 cm Box of 4 Silicon detectors : Area =10*10 cm2 Detector Thickness =300um Source of protons with kinematics from reaction placed at (0,0,0) No target X Z Y INPUT: Energy Resolution Strip pitch size Thickness detector (punch through) Target thickness effect STUDY of the  θ and  Ex

PARTICLE ARRAY: Angular Resolution If Strip pitch ~ 1mm ->number of channels for 10 cm detector 100*100= detectors =6x10000 channels (pad-type detector) 6 detectors =6x( ) channels (strip-type)

PARTICLE ARRAY: Target Effect Effect of the angular and energy loss straggling on the  θ,  Ex X Y Z Target thickness 0.5 mg/cm2 1 mg/cm2 2 mg/cm2 Source of (0,0,0) Strip pitch and thickness fixed = 1mm, 300μm

PARTICLE ARRAY: Angular Resolution (target in)

PARTICLE ARRAY: Ex Resolution (target in)  Ex ~ 140 keV (0.5mg/cm2)  Ex ~ 170 keV (1mg/cm2)  Ex ~ 225 keV At high energies, emission angles close to 90 degrees, protons see more material

PARTICLE ARRAY: Excited States (no target) 133 Sn keV keV keV keV 3700 keV E (keV)FWHM gs174 keV keV keV keV keV 132 Sn(d,p) 133 Sn* Excitation energy resolution reconstructed from the proton energy

PARTICLE ARRAY: Excited States (target in) 132 Sn(d,p) 133 Sn* 0.5 mg/cm21 mg/cm22 mg/cm2 Effect of the target thickness in the Energy- Angle distributions: Punch-through at lower Ep Low the Ep due to the energy loss ->threshold Increases the  Ep -> difficult to separate states 133 Sn keV keV keV keV 3700 keV 1 mg/cm20.5 mg/cm2

PARTICLE ARRAY: Excited States (target in) Target thickness worsens the resolution in Ex

PARTICLE ARRAY: INTERACTION POINT Assuming reaction can take place at any Z < Target Thickness X and Y are defined by the beam spot size 1 mg/cm21 mg/cm2 +inter point

PARTICLE ARRAY: RANDOM INTERACTION POINT The main source comes from the uncertainty on the z-coordinate Beam spot size negligeable FWHM 203 keV 221 keV 280 keV 315 keV 418 keV E (keV)FWHM gs174 keV keV keV keV keV 133 Sn keV keV keV keV 3700 keV FWHM 362 keV keV 778 keV keV

EXPERIMENTAL DATA: 132 Sn(d,p) 133 Sn at Oak Ridge Courtesy K. JONES preliminary Data will be an input for the event-generator ->Realistic implementation of the cross sections 160 um/cm2 target of CD2 at 4.7 MeV/u

132 Sn(d,p) 133 Sn at 10 AMeV Gamma array (simulations)

GAMMA ARRAY: VALUES OF GAMMA RAYS IN THE LAB : DOPPLER SHIFT Θ lab(degrees)  ~ 0.2 -> 10 AMeV E  =4 MeV -> [3.4,4.8] MeV  ~ 0.3 -> 35 AMeV E  =4 MeV -> [2.9,5.4] MeV  E  /E  tot ~  E  /E  int +  E  /E  dop

GAMMA ARRAY: RESOLUTION: DOPPLER BROADENING Θ lab(degrees)  E  /E  (%) E  lab = f( θ,  ) ->  E  /E  dop ~ f( θ )  E  /E  ~ 0.5 % E=1MeV -> 5 keV  θ ~ 2 o D=8 cm Crystal Size  θ 2.8 mm 2 o 3mm for a detector size of 12cm ->40x40 =1600 ch detector 6 detectors ->6x 1600=9600 channels

GAMMA ARRAY: RESOLUTION: INTRINSIC  E  /E  int ~ F. Notaristefani NIM A480 (2002) Other materials: LaBr3(Ce),LaCl2 To be studied  E  /E  int ~ 13.4 % at 662 keV ~ 90keV

Z X Y GAMMA ARRAY: SIMPLE GEOMETRY INPUT: Distance to (0,0,0) = 5 cm Area =10*10 cm2 Detector Thickness =3 cm Source of gamma rays placed at (0,0,0)

GAMMA ARRAY: Gamma resolution Meausrement of gamma rays in coincidence with particle is mandatory when dealing with thick targets.

GEOMETRY : Preliminary M. Labiche

FURTHER WORK  Study of different materials for the Calorimeter  Implement realistic cross sections in the event-generator  In-beam test with the TIARA+MUST2+EXOGAM+VAMOS array  Implement realistic geometry to determine efficiencies

200 μm thick 400 μm thick μm thick ~ 40 times thicker t The tickness determines the upper limit in Total energy and angle before the particles punch-through. The energy rises steadily and therefore not much gain in angular distributions PARTICLE ARRAY: Thickness detector

PARTICLE ARRAY: Ex Resolution Ex=f(Ep, θ )