Modular Neutron Detector Array for Protein Crystallography Beam Lines

Neutron techniques play a critical role in developing fundamental understanding that drives the bioenergy research, biosystems engineering to develop microbes and plants, and environmental microbiome research. While the importance of neutron techniques in these research areas has been well established, challenges they present have not yet been resolved. A fundamental limitation in studying biological specimens is the small sample size which causes poor signal which when coupled with typical gamma background, results in a poor signal-to- noise ratio (SNR). Also, proteins are large and scatter weakly. Thus, weak signal and poor SNR makes it difficult to characterize crystals, requires excessive beamtime, and makes it impractical to study many critically important specimens. The problem will be addressed by developing a modular detector that effectively discriminates neutron signal from gamma background while providing very high spatial resolution and high detection efficiency. A detector assembled using multiple modules will provide continuous cylindrical or spherical active surface, large solid angle coverage of 2p or higher, and will be significantly more cost effective compared to detector systems employed in current instruments. The goal of the proposed Phase I is to demonstrate feasibility of our approach. We will focus on designing the neutron sensor through simulations and fabricate it using advanced materials synthesis methods. The key components of the detector will be fabricated, and a prototype detector will be assembled. The detector will be thoroughly evaluated and validation of its performance in biological space will be demonstrated. A high performance detector providing angular coverage of ~2p solid angle with high neutron-gamma discrimination and minimal or no dead area between active regions will find numerous uses at conventional beamlines, and even in laboratory setups that make use of portable neutron sources. Such an instrument will be well suited for determining atomic positions and displacement parameters of light elements (such as hydrogen) next to heavy metals in proteins, advanced materials, or new drugs, and will be an ideal solution for studying magnetic structures, phase transitions, disorder, and local structure phenomena. Research in each of these areas will directly benefit public as it will accelerate the development of new drugs, novel materials, and systems, all of which have a direct impact on health care, quality of life, addressing nationĺs future energy needs, and will permit widening of our technology base.