High Rate Large Area Enriched Boron Neutron Detector for SNS

With the recent announcement of plans to ramp up the operation of the Spallation Neutron Source (SNS) facility to 1 megawatt, the available thermal neutron flux will be pushed at least an order of magnitude above that achievable at any other neutron science facility. This markedly increased flux imposes extreme requirements on imaging detectors at many of the target stations, which cannot be met without fundamental detector improvements. This project will develop a detector technology based on the detection of reaction products in the gas of a thin straw detector. By using a dense-packed array of such straws, which can be more than 1 meter in length, efficient high resolution imaging can be achieved with a quantum leap in integral and differential counting rate. In previous work, a complete 1 m2 neutron straw imaging system, utilizing natural boron-carbide straw coating, was developed. In Phase I, this development was extended by investing in expensive 10B4C sputtering targets and constructing a 1 meter detector module that demonstrated a five-fold increase in stopping power. In Phase II, a 22 module 1 m2 single layer detector will be fabricated. Because the outsourced sputtering targets represent more than 80% of the total cost, an in-house reel-to-reel coating system for production of large quantities of the requisite coated foil also will be developed. Commercial Applications and other Benefits as described by the awardee: The economical reel-to-reel production technique should enable the production of m2 imaging detectors at a very small fraction of the cost of currently envisaged detectors based on 3He. Because the availability of 3He on earth is extremely limited, its utilization in the thousands of detectors currently contemplated is very unrealistic. In contrast, the 10B isotope is extremely plentiful and cheap, and therefore the innovative manufacturing capability should meet a very significant need in neutron detection