Young Researchers Session in IFIN-HH 2016 Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH Complete angular distribution measurements for the study of 156Gd nucleus Alina-Nicoleta IONESCU Young Researchers Session in IFIN-HH 2016

Outline 1. The motivation of the 156Gd nucleus study 2. The experimental device - Q3D magnetic spectrometer - Focal plane detector 3. Experimental conditions and results 4. Conclusions

1. The motivation of the 156Gd nucleus study -represents an ideal part for the study of collective motion - the purpose- to study the 0+ excited states which are poorly understood - the motivation – the transfer strength to excited 0+ states in even-even Gd nuclei should increase linearly with the boson number -we used the (p,t) transfer reaction – it helps us to observe the 0+ excited states

2. The experimental device Q3D magnetic spectrometer - installed in the Maier-Leibnitz-Laboratory for Nuclear and Particle Physics of LMU Munich and TU Munich consists of a quadrupole magnet (Q) and three dipole magnets (3D) - allows the separation of the reaction products - has an energy resolution of dE/E=2x 10-4 can be rotate to measure angular distributions

2. The experimental device Focal plane detector consists of a chamber filled with 500 mbar isobutane, two proportional detectors and a scintillator - provides information about the position of the particles - the scintillator is used to measure the residual energy of the particles

3. Experimental conditions and results E=23 MeV The beam current intensity was about 2 mA The thickness of the target= 50 mg/cm2 - deposited on a carbon foil with a thickness of 4.1 mg/cm2 We performed measurements at three magnetic settings at 8 angles: 5o, 10o, 14o, 17o, 23o, 30o, 35o, 40o Tritons spectra for the second magnetic settings

3. Experimental conditions and results The calibration reaction used Qvalue=-5815.451 keV Qvalue=-6659.881 keV Qvalue=-6152.281 keV Qvaluedifference=336.837 keV Qvaluedifference=844.430 keV

3. Experimental conditions and results The calibration reaction used Etrit=f1(Channel) Fascicul de protoni Tritoni 156Gd 158Gd

3. Experimental conditions and results The calibration reaction used Etrit=f1(Channel) Eexcit=f2(Etrit)

DWBA calculations - Distorted Wave Born Approximation is the most useful one in direct nuclear reaction theory - Is used to extract the value of transferred angular momentum - DWBA calculations were performed using CHUCK3 code - CHUCK3 is a code which uses optical model parameters

3.Experimental conditions and results Angular distributions- old data q (deg.) ds/dW (mb/sr) 0+ states

3.Experimental conditions and results Angular distributions- new data

3. Experimental conditions and results 0+ states

4. Conclusions 1. We studied the 156Gd nucleus at an incident energy of 23 MeV 2. The resulted tritons were recorded using a high-resolution detector and Q3D magnetic spectrometer 3. Calibration reaction 154Gd(p,t)152Gd in order to calculate the excitation energies for our reaction 4. States with transferred angular momentum with values between 0 and 4 5. We confirmed the prediction of the model

Thank you for your attention!