Update: CERN have released a summary on Building and characterising the IDS Neutron Detector prototype bars which can be read below.
 

 
Following on from last weeks update on the tests being carried our by CERN with lightite® sheeting, we can now bring you some of the results which show why Lightite® sheeting is the only solution for building their incredibly sensitive neutron radiation detectors.

We spoke with Miguel and he talked us through the tests they carried out with our sheeting, along side some other materials. The results were indistinguishable and showed Lightites reflectance and light containment properties were unparalleled.

Here’s Miguel on what they were testing for and the results they received:

Regarding the tests we performed, we use three validation measurements for each detector we build.

CERN detector wrapped in lightiteThe first one is that we can observe a signal when using a radiation source with the detector. If the wrapping is too thin or compromised it will let the rooms light though to the detector. In that case the light amplification devices we use, photo multiplier tubes will stop working, as they cannot cope with intense sources of light. The Lightite® sheeting has no problem fully blocking external light with a single layer.

The second test is to evaluate the reflective properties of the detector combined with the wrapping. What we are interested is that the wrapping reflects as much light as possible and as fast as possible. I’ll get to each point individually.

The amount of light we estimate by using a reference radiation source located. By increasing the amplification voltage and measuring the total current in our amplification tubes (gain) we get a picture of the light output profile. We measure this profile for both regular double wrapping and single easy grow wrapping and found no difference.

The second aspect, timing properties, refer to the effective index of refraction light “sees” when traveling in our detector. A small index of refraction is advantageous to improve the resolution, the time difference, in our detector, as it is the value we use to calculate the neutron speed. In this case we measure the reference radiation source at 10 cm intervals in the detector and track the time it takes to arrive to each photo amplifier. Of course, the speed of light will be the slope, distance/time. In the double wrapped bars we observed 16(1)cm/ns, in single layer we observe 16.5(1) cm/ns, essentially the same result, as they are within the 1 ns error of the measurement.

A presentation with the data discussed can be seen below. We will update you on any further results we get from this exciting project.