Investigating timing properties of modern digitizers utilizing interpolating CFD algorithms and the application to digital fast-timing lifetime measurement

The performance of two implementations of digital real-time interpolating constant fraction discriminator algorithms with respect to fast-timing lifetime measurements are investigated. The implementations integrated in two different digitizers were evaluated in terms of the effects of tuning parameters of the digital CFDs and the influence of different input amplitudes on the time resolution and time walk characteristics. Reference is made to the existing analog standard of fast-timing techniques. The study shows, that the timing performance of both modules is comparable to established fast-timing setups using analog constant fraction discriminators, but with the added benefit of digital processing. Both digitizer modules were found to be highly effective and user-friendly instruments for modern fast-timing requirements.Comment: 13 pages, 16 figure

Inhibition of 2,5-hexanedione formation following exposure to n-hexane or a commercial hexane mixture

Bibliography: p. 99-11

Lifetime measurements and shape coexistence in Sr-97

Delayed gamma rays from neutron-rich A = 97 fission fragments were measured using the Lohengrin spectrometer at the high-flux reactor of the Institut Laue-Langevin in Grenoble. Several lifetimes of excited states in Sr-97 were measured using the fast-timing technique. The nucleus Sr-97 exhibits shape coexistence and is located exactly at the border of the spherical (N = 60) ground-state deformation. It is of particular interest to study the shape-coexisting structures at the spherical-deformed border (N = 59). The determined lifetimes within this work are compared to an interacting boson-fermion model calculation that is based on the microscopic energy density functional to provide a better understanding of the spherical-deformed border in strontium isotopes

Lifetime measurements in <math><mmultiscripts><mi>Mo</mi><mprescripts/><none/><mn>92</mn></mmultiscripts></math>: Investigation of seniority conservation in the <math><mrow><mi>N</mi><mo>=</mo><mn>50</mn></mrow></math> isotones

International audienceExcited states in the yrast and negative parity bands in Mo92 were populated in two different experiments using the Zr90(α,2n)Mo92 and Nb93(p,2n)Mo92 fusion-evaporation reactions at the Cologne FN Tandem accelerator and measured using a hybrid setup of high purity germanium and lanthanum bromide detectors. Lifetimes of the excited 21+, 41+, 61+, 81+, 51−, 71−, and 91− states were measured using the γ-γ fast-timing technique. The newly measured lifetime of the 41+ state differs from the recently published value measured using the recoil distance Doppler shift method. Experimental B(E2) strengths of excited states in Mo92 are used to predict theoretical B(E2) values in the N=50 isotones from Tc93 up to Rh95 using semiempirical calculations in the single-j orbital 0g9/2 for the protons

Triaxiality in the mid-shell nucleus Pd-112

Lifetimes of low-spin excited states in Pd-112 were measured using the recoil-distance Doppler-shift technique. The nucleus of interest was populated in a (110)pd(O-18, O-16)Pd-112 reaction using the Cologne FN Tandem accelerator. Three lifetimes of ground-state band members and one lifetime of the y band were measured. From these lifetimes reduced transition probabilities were extracted and compared to interacting boson model, gamma-soft calculations, and Davydov calculations. The lifetime of the 2(gamma)(+) gives some insights on the nuclear shape and structure of the gamma band. The deduced transition rates show an indicator for a rigid triaxial nucleus as well as more indicators for a gamma-soft nucleus

Lifetime measurements in <math><mmultiscripts><mi>Mo</mi><mprescripts/><none/><mn>92</mn></mmultiscripts></math>: Investigation of seniority conservation in the <math><mrow><mi>N</mi><mo>=</mo><mn>50</mn></mrow></math> isotones

International audienceExcited states in the yrast and negative parity bands in Mo92 were populated in two different experiments using the Zr90(α,2n)Mo92 and Nb93(p,2n)Mo92 fusion-evaporation reactions at the Cologne FN Tandem accelerator and measured using a hybrid setup of high purity germanium and lanthanum bromide detectors. Lifetimes of the excited 21+, 41+, 61+, 81+, 51−, 71−, and 91− states were measured using the γ-γ fast-timing technique. The newly measured lifetime of the 41+ state differs from the recently published value measured using the recoil distance Doppler shift method. Experimental B(E2) strengths of excited states in Mo92 are used to predict theoretical B(E2) values in the N=50 isotones from Tc93 up to Rh95 using semiempirical calculations in the single-j orbital 0g9/2 for the protons