From imaging algorithms to quantum methods Seminar

Monday 2 Mar 2026, 10:00 → 11:30 Europe/Warsaw

https://cern.zoom.us/j/66151941204?pwd=n7upvvZYibexBhbtyn5kvTpy36L0Wo.1 (Zoom)

Konrad Klimaszewski (NCBJ), Wojciech Krzemien (NCBJ)

Zoom link: https://cern.zoom.us/j/66151941204?pwd=n7upvvZYibexBhbtyn5kvTpy36L0Wo.1

**Title:** Neutron Activation Techniques in Detecting Hazardous Materials and Cancer Treatment
**Presenter:** Michał Silarski
**Date:** 02.03.2026

### Participants
Michał Silarski (MS)
Aurelien Coussat (AC)
Wojciech Krzemień (WK)
Konrad Klimaszewski (KK)
Michał Morozowsi (MM)
Kamil Dulski (KD)
Michał Obara (MO)
Roman Shopa (RS)
Lech Raczyński (LR)
Mateusz Bała (MB)
Aleksander Ogonowski (AO)

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### Discussions

**WK:** How important is the energy resolution in the context of realistically distinguishing hazardous materials?
**MS:** Maybe this resolution is enough for this purpose.

**WK:** Guides → what about the geometric acceptance for gammas?
**MS:** We can only increase the elastic scattering fraction. For a 10-second scan, the distance should be about 10 cm to be efficient.

**WK:** How do you transport the source close enough to the target?
**MS:** It is the size of a laptop, so it can be placed in something like a submarine.

**WK:** When you analyse those energy spectra, are there any more sophisticated methods to analyse them, e.g., some deconvolution with predefined shapes, etc.? What neural network has been tried?
**MS:** It was an FF network, but the results are too optimistic 😉.

**WK:** Can you measure the background shapes independently?
**MS:** Yes, it is mostly exponential. It was done by KD.

**LR:** What are the real input data for the reconstructions?
**MS:** We work with histograms. We could have access to the full signals, but that would require too much storage space.

**AC:** What does it mean that you can take tomographic pictures with Sabat?
**MS:** The idea is that you could measure the signal from different positions and angles. You can take many projections, so in principle you could obtain a 3-D image of the object. In the lab, this can be done by rotating the source.

**AC:** I was wondering if there are some objects that you should not or cannot scan.
**MS:** Most of the chemicals of interest are fine with this technique. Fluorine could be a problem, and nitrogen is also a challenge due to small cross sections.

**KK:** Do you think that just looking at those ratios without nitrogen is enough to distinguish between explosive and non-explosive materials?
**MS:** There are other lines you can focus on to distinguish them.

**KK:** What is the real range at which you can detect materials outside of the guides?
**MS:** Any water layer badly affects the elemental ratios, so that is problematic. The realistic distance is about 15 cm.

**KK:** Do you have any idea what materials should be used inside the guides?
**MS:** If we were rich, we could use helium. Probably we should use decarbonized steel of a few millimeters.

**KK:** How is the DOI measured in your detector for boron?
**MS:** Based on simulations, it might be possible using the difference in the flight time distribution, but this needs to be checked under realistic conditions.