[Fast-Neutrons] Congrats! Re: First fast neutron images at Phoenix

Michael Taylor Michael.Taylor at phoenixwi.com
Mon Nov 18 18:32:39 CET 2019


I got a quote from Fuji just a couple months ago for image plates, no GE involved. GE health sciences used to sell the 8”x10” ones made by Fuji as of a few years ago but I haven’t looked into them recently. We do buy directly from Fuji.

Yes, you’re right that we need 20 to do a swap out and turnaround.

Resolution wise, we need about 100um. Per the upcoming new astm standards for digital imaging, we are getting about 50um on CR, which some customers have already seen and are quite pleased with. If a detector can’t do at least 100um resolution for a 14”x17” field of view in less than 30 minutes, it’s a non-starter for us.

I’m surprised about the field of view you mention. Are there aberrations or distortions at that focal length and distance from the mirror?


On Nov 18, 2019, at 11:15, Alan Hewat <alan.hewat at neutronoptics.com> wrote:

Perhaps Fuji does still make neutron image plates (NIPs), but Burkhard is right that GE at least markets them according to this document<https://linkprotect.cudasvc.com/url?a=https%3a%2f%2fcdn.gelifesciences.com%2fdmm3bwsv3%2fAssetStream.aspx%3fmediaformatid%3d10061%26destinationid%3d10016%26assetid%3d16330&c=E,1,PAZEeH57Ah7hDWqcZzenErg1tGP6QJpZu_Yp_jst5NKWLLozwCzBNpgmHQANGKU9tqoPbgRVcG9x5CbirIq8Kov6KDz7E7tfu1yKvqSVPm8a-w_bYoawN9BC&typo=1>.

I'm not saying that NIPs are not a good solution if you need 10 different imaging stations around your source, and I am impressed by your thermal neutron images, even if they did take 20 minutes at 10**4 n.cm-2.s-1. But you still need an image plate reader (~$50K) and you have to count the time needed to dismount the plate, read it and erase it. I guess you change them all at the same time, since you need to stop the beam to do it, and you probably want a second set of 10 plates to swap in.

BTW, we have made CCD cameras that size for ~€15K each, not €70K, though ten would still be expensive :-) The specs would be:

  *   "Kodak" full frame (36x24mm)  KAI11002<https://linkprotect.cudasvc.com/url?a=http%3a%2f%2fwww.onsemi.com%2fpub%2fCollateral%2fKAI-11002-D.PDF&c=E,1,Gd54-iZ3587YJpUSbCxIY_SJZxez8l_CvMVSySoCcau9WYaN8Az9q8rHRZii-GPqX4JEGAehGDFrCHOLcZXEWpMTmFuN5HrkIPXfWwRhNGgCRQ,,&typo=1>  CCD
  *   Nikon Nikkor 50mm f/1.2 lens (a great lens for $600).
  *   Distance scintillator-CCD 750mm (not huge) for a FOV of 500x336mm  (20"x13")
  *   Optical resolution 125 microns
  *   Real resolution ~200 microns depending on L/D, and sample-scintillator distance.

If you have even more money, you could buy a system like CYCLOPS<https://linkprotect.cudasvc.com/url?a=http%3a%2f%2fneutronoptics.com%2fcameras.html%23cyclops&c=E,1,dRTJhEBFJRBxfLyVaRGaR0TPeJXYHrWlFKeGn8avpo7b_4bUefKKXRdfzw3oQR0P1L8jkvighciVpKCUIfBqDp-OHklgIciPQWNFhZ_zhkoDpuw9YHY,&typo=1> :-)

Regards, Alan.

On Mon, 18 Nov 2019 at 17:19, Michael Taylor <Michael.Taylor at phoenixwi.com<mailto:Michael.Taylor at phoenixwi.com>> wrote:
Fuji does indeed make the image plates, I know our vendor quite well and talked with him just Friday about making more; they have about 100 in stock.

I completely agree that a CCD system would be better for efficiency but there is an inherent problem for our application. Our customers need high throughout and their traditional setup is using a 14” x 17” field of view. When you make a screen that large, you have to move your camera much farther away to see the full FOV and then you drop the efficiency.

The other factor is the cost. These image plates are $3500 each, and we need 10 for the full system, so $35,000. That’s half the price of a single good camera.

I’ve got a lot of emails from folks this morning so thank you all for your feedback!


On Nov 18, 2019, at 05:25, Alan <alan.hewat at gmail.com<mailto:alan.hewat at gmail.com>> wrote:

OK, perhaps Fuji now produce more efficient neutron imaging plates. I only know that we have used Fuji plates at ILL for 25+ years for Laue diffraction and had great difficulty persuading Fuji, with the help of a famous Japanese scientist, to make special high efficiency plates for us. The market is very small, so Fuji just converted ordinary x-ray plates to their commercial neutron product. Those commercial plates were less efficient and also had magnetic backing to stick to a support, not ideal for neutrons.

I would be interested in a comparison of images with an image plate, a photographic film in contact with a scintillator, a CCD camera, and a flat solid state detector. The latter is also developed for x-rays, contains materials that are activated by neutrons, and as Eberhard says, may be damaged by the beam.

   Dr Alan Hewat, NeutronOptics, Grenoble, FRANCE
                               from my telephone
<Alan.Hewat at NeutronOptics.com> +33.476.98.41.68

On Mon, 18 Nov 2019, 11:52 Lehmann Eberhard (PSI), <eberhard.lehmann at psi.ch<mailto:eberhard.lehmann at psi.ch>> wrote:
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 …



Paul Scherrer Institut
Dr. Eberhard H. Lehmann
Forschungsstrasse 111
5232 Villigen PSI

Telefon: +41 56 310 29 63
E-Mail: eberhard.lehmann at psi.ch<mailto:eberhard.lehmann at psi.ch>

Von: fast-neutrons-bounces at neutronsources.org<mailto:fast-neutrons-bounces at neutronsources.org> <fast-neutrons-bounces at neutronsources.org<mailto:fast-neutrons-bounces at neutronsources.org>> Im Auftrag von Alan
Gesendet: Montag, 18. November 2019 10:43
An: fast-neutrons at neutronsources.org<mailto: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

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

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!


> 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
D-85748 Garching
Tel. +49 89 289-12185

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Dr Alan Hewat, NeutronOptics, Grenoble, FRANCE
<Alan.Hewat at NeutronOptics.com> +33.476.98.41.68
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