T. A. Bredeweg

Background identification and suppression for the measurement of (n,γ) reactions with the DANCE array at LANSCE

Abstract In the commissioning phase of the DANCE project (Detector for Advanced Neutron Capture Experiments) measurements have been performed with special emphasis on the identification and suppression of possible backgrounds for the planned (n,γ) experiments. This report describes several background sources, observed in the experiment or anticipated from simulations, which will need to be suppressed in this and in similar detectors that are planned at other facilities. First successes are documented in the suppression of background from scattered neutrons captured in the detector as well as from the internal radiation. Experimental results and simulations using the GEANT code are compared.

Acquisition-analysis system for the DANCE (detector for advanced neutron capture experiments) BaF/sub 2/ gamma-ray calorimeter

The DANCE detector is a segmented 4/spl pi/ gamma-ray calorimeter for measuring (n, /spl gamma/) and (n,fission) cross-sections of stable and long-lived radioactive isotopes. DANCE uses waveform digitization to acquire the basic gamma-ray data, which maximizes the information available for event reconstruction, but has necessitated the development of several techniques for handling the resulting high data rates. This paper describes the basic experimental requirements for acquisition and analysis and how we have satisfied these requirements primarily by extending existing acquisition and analysis frameworks.

Spin measurements for

We have determined the spins

^{147}

J

Sm

of resonances in the

+n

^{147}\mathrm{Sm}

resonances: Further evidence for non-statistical effects

(

Measurement of the {sup 157}Gd(n,{gamma}) reaction with the DANCE {gamma} calorimeter array

n,\ensuremath{\gamma}

Ni63(n,γ) cross sections measured with DANCE

) reaction by measuring multiplicities of

Two detector arrays for fast neutrons at LANSCE

\ensuremath{\gamma}