4.2: Counting rate capability

This deliverable, “Counting rate capability”, is part of the task 4.2 “The Intensity Frontier”. It aims to report the rate capability of the technology used for the Multi-Blade detector.

The Multi-Blade is a 10B-based detector conceived to face the challenge of the counting rate capability arising from the neutron reflectometry at the European Spallation Source (ESS). The current detector technology, based on 3He-based detector, is reaching fundamental limits in counting rate capability and position resolution. [Cam+11] The problem with count rates is a general one, and the ESS solution could potentially be applied to existing instruments at other neutron sources. [PHW14]

The work on the Multi-Blade began in 2011 at the Institut Laue-Langevin (ILL) where two technology prototypes were built and tested showing promising results. [Pis14] The European Union is now sponsoring the Multi-Blade detector through the BrightnESS project [ESS] that aims to realise detectors optimised for these high rates.

The Multi-Blade design has been improved since the beginning of BrightnESS as part of task 4.2. A new demonstrator has been built and tested within the collaboration of ESS, Lund University (LU) and the Wigner Research Centre for Physics, Hungary. It has been shown that aside from the improvement in counting rate capability, the Multi-Blade design also decreases the spatial resolution by about a factor three over state-of-the-art 3He-based reflectometer detectors. These and other results including the path ahead for this project will be presented. The Multi-Blade design is the one favoured as a development path to be pursued for reflectometry at ESS.

At present, a data rate of 40 kHz/mm2 is achieved. This result is already very close to the desiderata target of 100 kHz/mm2 and it is a factor 100 above the state of art of the available technology (300Hz/mm2). Calculations indicates that this design is capable of reaching the given goal.

DOI: https://doi.org/10.17199/BRIGHTNESS.D4.2