NeuLAND - FAIR

1. Introduction and Overview
1.1. NeuLAND – A Key Instrument of R 3 B for
High-Resolution Multi-Neutron Detection
The acronym R 3 B stands for Reactions with Relativistic Radioactive Beams. The
R 3 B experiment will be installed at the high-energy branch focal-plane of the Super-
FRagment-Separator Super-FRS at the FAIR Facility for Antiproton and Ion Research.
The R 3 B activity is embedded into the NUSTAR (NUclear STructure, Astrophysics and
Reactions) pillar of the FAIR experimental program. The design and construction of the
R 3 B facility is being pursued within a large international collaboration, the R 3 B collaboration,
which is a consortium of more than 200 scientists from more than 20 countries.
The physics cases and the conceptual layout of the experiment including its instrumental
parts have been laid out in the Conceptual Design Report for FAIR [CDR-01] in 2001
and in more technical detail in the R 3 B Technical Proposal [R3B-05] in 2005. Since
then, an extensive R&D program has been pursued which led to the final design of the
different detection components. In this report, we describe in detail the technical design
of the neutron detector NeuLAND (New Large Area Neutron Detector). This detector
serves as a high-resolution time-of-flight spectrometer for neutrons in the energy range
from 100 to 1000 MeV. The superior time and position resolution of this detector in
conjunction with an excellent resolving power for multi-neutron events is the key for the
realization of the ambitious physics program of R 3 B and will enable the investigation of
nuclear reactions with unprecedented precision.
The R 3 B experiment will enable kinematically complete measurements of reactions with
relativistic beams up to energies of approximately 1 AGeV. (The upper limit in energy is
defined by the maximum magnetic rigidity of 20 Tm of the Super-FRS). The flexibility of
the setup with its detection systems allows us to accommodate experiments investigating
different types of reactions and physics cases. An overview on the physics subjects to
be investigated has been given in the Conceptual Design Report [CDR-01]. In the
next chapter we discuss a selection of physics cases for which the neutron detector
NeuLAND and its performance play an important role, which could be summarized in
the question: How do nuclear properties evolve as a function of isospin? This includes
nuclear-structure properties of short-lived nuclei with extreme neutron-to-proton ratios
as well as properties of asymmetric nuclear matter. Both, the experimental answers
to this question as well as a fundamental understanding from a theoretical point of
view, form the basis to the understanding and description of astrophysical objects and
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