Doppler-shift attenuation lifetime measurement of the 36 Ar2 1 + level

摘要: At TRIUMF, the TIGRESS Integrated Plunger device and its suite of ancillary detector systems have been implemented for charged-particle tagging light-ion identification in coincidence with $\ensuremath{\gamma}$-ray spectroscopy Doppler-shift lifetime studies low-energy Coulomb excitation measurements. As a test device, first ${2}^{+}$ excited state $^{36}\mathrm{Ar}$ was measured from line shape ${2}_{1}^{+}\ensuremath{\rightarrow}{0}_{\mathrm{g}.\mathrm{s}.}^{+}$ transition using attenuation technique following excitation. The line-shape signatures, vital precision measurements, were significantly improved by enhanced reaction-channel selectivity complementary approach kinematic gating digital rise-time discrimination recoiling charged particles silicon PIN diode array. determined comparisons between data simulated shapes generated our code as an input to Lindhard method, which then extended included class geant4. model-independent result $490\ifmmode\pm\else\textpm\fi{}50$ fs corresponds reduced quadrupole strength $B(E2;{2}_{1}^{+}\ensuremath{\rightarrow}{0}_{\mathrm{g}.\mathrm{s}.}^{+})=56\ifmmode\pm\else\textpm\fi{}6\phantom{\rule{0.28em}{0ex}}{\mathrm{e}}^{2}{\mathrm{fm}}^{4}$ agrees well previous intermediate energy thereby resolving reported discrepancies ${2}_{1}^{+}$ level this self-conjugate nucleus.