[Halld-tagger] [EXTERNAL] Re: good WSF candidate

[Richard T. Jones]

Hello all,

Here is a paper from LHCb with a passing comment at radiation damage
sensitivity in BCF-20 that seems highly relevant to what we are seeing in
the TAGM. Check out the following comment [p. 12], made in passing, about
BCF-20 being ruled out due to radiation damage sensitivity.

A significant problem with the 3HF fibre is the long decay time constant of
> 7 ns. For the proposed SciFi tracker upgrade, this is a substantial
> disadvantage. Including the 15 ns propagation time of the signal from the
> furthest positions, it significantly complicates the task of collecting the
> signal within a single bunch crossing interval. *Addition of a mirror to
> the fibre end further complicates the timing of the signal. Saint-Gobain
> has a fast, green (492 nm) scintillating fibre, the BCF-20, but the fluors
> were found to be damaged quite easily under irradiation and cannot be
> considered*


It would be interesting to know more about this. The full paper is attached.
-Richard

On Thu, Oct 23, 2025 at 12:10 PM zihlmann <zihlmann at jlab.org> wrote:

> Hi Richard,
>
> a good WSF candidate is BCF-92XL (seems to be very similar to what is used
> in PS)
> https://urldefense.proofpoint.com/v2/url?u=https-3A__luxiumsolutions.com_radiation-2Ddetection-2Dscintillators_fibers&d=DwIFaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=-MwMW0sKroUIjy-Lh9rb3KzmWIgdcbbr9_jez8RLmto&m=SmsWm3rOWbDNIfT4O6z0gKZvePuu2wHj_cxxOGNA2vQpZb64JmJKpyzI_7Desv5m&s=_j6qXYSa1bld8Fy72yvfZb-PWvWwApH4d5CL26DS9DY&e= 
>
> [image: WSF parameters]
>
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