München 2019 – wissenschaftliches Programm
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HK: Fachverband Physik der Hadronen und Kerne
HK 21: Structure and Dynamics of Nuclei III
HK 21.2: Vortrag
Dienstag, 19. März 2019, 14:30–14:45, HS 14
A new approach to determine nuclear-level lifetimes using the Doppler-shift attenuation method — •A. Bohn1, V. Everwyn1, M. Färber1, F. Kluwig1, M. Müscher1, S. G. Pickstone1, S. Prill1, P. Scholz1, M. Spieker2, M. Weinert1, J. Wilhelmy1, and A. Zilges1 — 1University ofCologne, Institute for Nuclear Physics — 2NSCL, Michigan State University, MI 48824, USA
The combination of the γ-ray detector array HORUS, consisting of 14 HPGe detectors, and the target chamber SONIC, housing 12 silicon detectors, enables the determination of nuclear-level lifetimes in the range of sub-picoseconds via the Doppler-shift attenuation method (DSAM) [1,2,3].
The measurement of p-γ-coincidences allows to determine the complete reaction kinematics. Hence, centroid-energy shifts can be extracted in proton-gated γ-ray spectra, depending on the γ-emission angle θ.
In the standard analysis, the attenuation factor F(τ) is determined by using its correlation with the slope of Eγ(cos(θ)). Alternatively, the spectra measured at different angles can be corrected for their expected Doppler shifts assuming different F(τ) values. Then, a FWHM minimization for the transition of interest can be performed to obtain the final value of F(τ). This procedure might be more efficient to determine lifetimes of weakly excited states.
First results from DSAM experiments on 130Te will be presented. Supported by DFG (ZI 510/9-1). A.B. is supported by the BCGS.
[1] A. Hennig et al., NIM A 794 (2015) 171.
[2] M. Spieker et al., Phys. Rev. C 97 (2018) 054319.
[3] S. G. Pickstone et al., NIM A 875 (2017) 104.