Abstract
The upgrade of the cold neutron triple axis spectrometer FLEXX, a work-horse instrument for inelastic neutron scattering matching the sample environment capabilities at Helmholtz-Zentrum Berlin, has been successfully accomplished. Experiments confirmed an order of magnitude gain in flux now allowing for intensity demanding options to be fully exploited at FLEXX. In this article, we describe the layout and design of two newly available FLEXX instrument options in detail. The new Heusler analyzer gives an increase of the detected polarized neutron flux due to its superior focusing properties, significantly improving the feasibility of future polarized and neutron resonance spin echo experiments. The MultiFLEXX option provides simultaneous access to large regions in wavevector and energy space for inelastic excitations thus adding mapping capabilities to the spectrometer.
Highlights
The BER II neutron source and its instruments have recently undergone major developments
Experiments performed during the commissioning phase confirmed an order of magnitude gain in intensity as a result of the upgrade [4]
In this article we describe the basic design features of MultiFLEXX, a new optionally available secondary spectrometer
Summary
The BER II neutron source and its instruments have recently undergone major developments. An extensive upgrade program was conducted which included the exchange of the cold source moderator cell while the complete guide system in the Neutron Guide Hall I was rebuilt with state-of-the-art supermirror guides [1]. The cold neutron triple axis spectrometer FLEX [2], a work-horse instrument for inelastic neutron scattering matching the low temperatures and high magnetic fields sample environment capabilities at HZB, was upgraded and relocated to a guide end position [3]. This article is organized as follows: We first summarize the main new features of the upgraded FLEXX spectrometer and the comparison of its performance before and after the upgrade. The design principles of the MultiFLEXX option are described in Sect.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call