[Fast-Neutrons] Fuji no longer., GE it is... Re: Congrats! Re: First fast neutron images at Phoenix

[Burkhard Schillinger]

Fuji does not make them any longer, General Electrics has bought them.
We got a few from GE several years back - No time to dig up the  
information now, I'm travelling.

Best  regards

Burkhard




Zitat von Lehmann Eberhard (PSI) <eberhard.lehmann at psi.ch>:

> I disagree with Alan about the n-sensitive imaging plates: they are
> made by Fuji on a commercial base adding Gd to the X-ray sensitive
> material. Therefore the efficiency is not bad and much better than
> film methods …
>
> Regards
>
> Eberhard
>
> __________________________________________
> Paul Scherrer Institut
> Dr. Eberhard H. Lehmann
> WBBA/122
> Forschungsstrasse 111
> 5232 Villigen PSI
> Schweiz
>
> Telefon: +41 56 310 29 63
> E-Mail: eberhard.lehmann at psi.ch
>
> Von: fast-neutrons-bounces at neutronsources.org  
> <fast-neutrons-bounces at neutronsources.org> Im Auftrag von Alan
> Gesendet: Montag, 18. November 2019 10:43
> An: fast-neutrons at neutronsources.org
> Betreff: Re: [Fast-Neutrons] Congrats! Re: First fast neutron images  
> at Phoenix
>
> Hello Michael, Burkhard and Eberhard.
>
> Thank you Michael for these nice images. I too am impressed by the  
> resolution of your thermal images with an L/D of only 35, and agree  
> that it would be good to take thermal images with a camera rather  
> than a neutron image plate. The ordinary Fuji n-plates are just  
> x-ray plates with extra 6LiF and I think only ~10% efficient. ~20  
> years ago Fuji made special n-plates for ILL that were ~25%  
> efficient but they are no longer available (?). You should be able  
> to reduce the exposure well below 20 minutes with a camera and a  
> good 6LiF/ZnS thermal neutron scintillator even with only 10**4  
> n.cm-2.s-1. See the images Robert Zboray showed in Sydney from a  
> very low flux Triga reactor, one of which I reproduced in my Munich  
> talk.
>
> It would also be good to compare your fast neutron image with a  
> thermal neutron image using the same detector and L/D (with  
> different scintillators). With such small objects, that can be put  
> close to the scintillator, it would be interesting to see if fast  
> neutrons still have some advantage for imaging such defects.
>
> I also found Burkard's and Eberhard's comments about the best  
> material and thickness for a fast neutron Siemens star interesting.  
> It would be good to see images with these different resolution  
> objects. I also printed a plastic Siemens star, but 40 mm thick,  
> which I have not yet been able to test. A final trivial point;  
> please don't use exponent e4 instead of 10**4 for flux; e has a  
> different meaning for mathematicians.
>
> Thanks again for sharing. Alan
> ______________________________________________________
>    Dr Alan Hewat, NeutronOptics, Grenoble, FRANCE
>                                from my telephone
> <Alan.Hewat at NeutronOptics.com<mailto:Alan.Hewat at NeutronOptics.com>>  
> +33.476.98.41.68
>         http://www.NeutronOptics.com/hewat
> ______________________________________________________
>
> On Mon, 18 Nov 2019, 08:42 Burkhard Schillinger,  
> <Burkhard.Schillinger at frm2.tum.de<mailto:Burkhard.Schillinger at frm2.tum.de>>  
> wrote:
> Hello Michael,
>
> congratulations for these nice images!
> For a fast neutron image, that resolution is pretty good. Probably
> better than ours - which shows that a high collimation is also
> important for fast neutrons if you have large samples.
>
> I am also surprised again by your thermal image at L/D of only 35 -
> but that's what you get when you can put the samples up close to the
> detector.
>
>
> For an edge - about everything scatters fast neutrons, but I have
> tried with a 10 mm thick polyethylen pattern (Siemens Star) that was
> 3D printed at our lab. When putting it directly on the detector, it
> was a good measure to test the screen. The 1.5 mm thickness screen was
> much better than the 2.4 mm.
> Not sure what really happens if you take it further away - I assume
> that 10 mm thickness is a good compromise between attenuation and
> scattering blur. You might try 10 mm steel as well, but iron is also a
> diffuse scatterer.
> A perfect edge does not exist.
>
> Good luck with your new 'toys', and Happy Holidays!
>
> Burkhard
>
>
>
>
>> Good day to all,
>>
>> I am happy to announce that we've taken our first fast neutron
>> images at the Phoenix facility in Wisconsin, USA!  Our source is
>> operational now with a source strength of approximately 1.5e12 n/s
>> and an L/D of 450 to achieve a flux at the image plane of
>> approximately 5e5 n/cm^2-s.  Over the next few weeks, we will be
>> increasing our beam current and changing our target to a different
>> material.  We expect to get to full power and have a source strength
>> of 3e13 n/s and a flux at the image plane of approximately 1e7
>> n/cm^2-s.
>>
>> The image attached was taken using a Varex XRD 1621 digital detector
>> array and a PP:ZnS(Cu) screen provided by RCTritec.  The
>> scintillator field of view is 310mm x 310mm, but we plan to use the
>> full field of view of the detector eventually, which is 430mm x
>> 430mm.  The image was taken last night and acquired with 15 frames
>> at 20 seconds each.  The frames were then added and the offsets were
>> applied for background corrections.  The sample is a simulated M982
>> military round.  It is 155mm in diameter.  The outside casing is
>> 1/8" steel and the inside simulant is an HMX equivalent, 6% 6656
>> binder (simulated with 204 epoxy). Chemically it is similar to HMX
>> and RDX but with much less nitrogen.  I have outlined some of the
>> defects of interest that we want to see.
>>
>> We would like to measure the resolution of the system next so I
>> would like to ask if anyone has advice on what material to use as an
>> edge and how thick it should be?  We do not yet have any kind of
>> standard measurement technique for this that I'm aware of, so I
>> would like to know what others are doing.
>>
>> I've also attached a new image we acquired using thermal neutrons of
>> several different military grade .50 caliber ammunition.  We took an
>> X-ray image for comparison and that is shown as well.  The X-ray was
>> done at 350kV but I don't recall the current.  The neutron image was
>> acquired using our thermal neutron generator with heavy water
>> moderator, the L/D was 35 and the flux was approximately 1e4
>> n/cm^2-s.  The exposure time on a neutron sensitive image plate was
>> 20 minutes.
>>
>> I hope everyone is well, it was great to meet so many of you in
>> Garching last month and I wish you all happy holidays as they
>> approach us soon.
>>
>> Best regards,
>> Michael
>>
>> Michael Taylor Ph.D.
>> Neutron Radiography Product Manager
>> Phoenix LLC
>> 2555 Industrial Drive
>> Madison, WI 53717
>> 608-515-3214
>
>

-- 
Dr. Burkhard Schillinger
Technische Universität München - FRM II
Heinz Maier-Leibnitz Zentrum
Lichtenbergstr.1
D-85748 Garching
Germany
Tel. +49 89 289-12185