Vanadium-based neutron-beam monitor
(2019) FYSM60 20191Nuclear physics
Department of Physics
- Abstract
- A prototype invasive (quasi-parasitic) thermal-neutron beam monitor based on isotropic neutron scattering from a thin natural Vanadium foil and standard $^3$He proportional counters has been conceptualized, designed, simulated, calibrated, and commissioned. As the beam monitor is invasive, very low neutron-beam attenuation is a necessary characteristic. Further, response linearity over as wide a range of rates as possible is highly desirable. The prototype was first calibrated using radioactive neutron sources at the Source-Testing Facility at the Division of Nuclear Physics in Lund, Sweden. Subsequently, the prototype was commissioned with beams of neutrons at the V17 and V20 beamlines of the Helmholtz Zentrum in Berlin, Germany. Both low... (More)
- A prototype invasive (quasi-parasitic) thermal-neutron beam monitor based on isotropic neutron scattering from a thin natural Vanadium foil and standard $^3$He proportional counters has been conceptualized, designed, simulated, calibrated, and commissioned. As the beam monitor is invasive, very low neutron-beam attenuation is a necessary characteristic. Further, response linearity over as wide a range of rates as possible is highly desirable. The prototype was first calibrated using radioactive neutron sources at the Source-Testing Facility at the Division of Nuclear Physics in Lund, Sweden. Subsequently, the prototype was commissioned with beams of neutrons at the V17 and V20 beamlines of the Helmholtz Zentrum in Berlin, Germany. Both low attenuation and response linearity have been successfully demonstrated, indicating the concept is viable and worth continued development efforts. In this thesis, a monographic overview of the development of the prototype is presented. (Less)
- Popular Abstract
- I am sure you all got to use microscope at some point in your life. And you were able to see the things that would not be possible to see otherwise, didn’t you?
Well scientists need microscope all the time. Genetics need to see a structure of the genom and DNA, archeologists need to know what material they dug in the ground and in medicine the doctors will be interested what kind of tumor is in patients body. All of these require a very special microscope: a microscope that needs to be able to identify the placing of Hydrogen atoms. Such microscope can be build using neutrons. And ideally there has to be certain amount of these neutrons and they need to have certain speed at which they are flying.
The European Spallation Source (ESS) is... (More) - I am sure you all got to use microscope at some point in your life. And you were able to see the things that would not be possible to see otherwise, didn’t you?
Well scientists need microscope all the time. Genetics need to see a structure of the genom and DNA, archeologists need to know what material they dug in the ground and in medicine the doctors will be interested what kind of tumor is in patients body. All of these require a very special microscope: a microscope that needs to be able to identify the placing of Hydrogen atoms. Such microscope can be build using neutrons. And ideally there has to be certain amount of these neutrons and they need to have certain speed at which they are flying.
The European Spallation Source (ESS) is going to create such neutrons: it will be the biggest microscope for hydrogen-rich material in the world!
We can imagine the ESS target (a place when the neutrons are created) as a geyser. Instead of water the geyser is producing sweets (neutrons) and these sweets are flying in all directions. And over 20 children (20 different scientific stations) are standing around the geyser, wanting to consume the sweets at different rates (some of them need 2 chocolate bars per hour, some of them 10 dried bananas per hour just as our biologist and archeologist each want a different number of neutrons with different properties). In order to ensure that every child has a correct number of sweets, the entire geyser is enclosed in a bunker, leaving tunnels to each child. Along the tunnels, a policemen (choppers) are standing, not allowing bananas to the chocolate-lovers and regulating the rate. And finally, next to the policements, there are student workers (beam monitors) who sit with their notebooks and write down the number of bananas and chocolates flying around, checking that the policemen do their jobs.
This thesis is introducing a very devoted student worker (beam monitor), that does not give up even if the the number of sweets is insane and he works all the time, never has a break.
In real life, of course the beam monitor is not a student, but rather a piece of equipment placed in order to verify, that the choppers allow for the correct energies and rates of neutrons.
Also, for little particles the monitor (student) cannot just observe the neutrons, it has to interact with them (absorb them=eat them or scattered them= hit them with the baseball bat).
This beam monitor for this thesis consists of a thin Vanadium foil from which only tiny part of the neutrons (sweets) are scattered (hitted with the baseball bat), and these are then stored in the detectors (boxes) placed around this foil. This scattered part is so tiny, that the kids standing around the bunker will not even notice, the change in rate of sweets. What is stored in the detectors around the foil is then analyzed and therefore the correct functionality of choppers can be verified.
Thanks to the policemen choppers and the working-hard students that control the work of the policemen, the neutrons are delivered correctly to the biologist and archeologist and now they can fully use them as a best microscope in the world. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8988026
- author
- Maulerova, Vendula LU
- supervisor
- organization
- course
- FYSM60 20191
- year
- 2019
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- thermal neutrons Helmholtz-Zentrum Berlin Neutron-beam monitor Vanadium
- language
- English
- id
- 8988026
- date added to LUP
- 2019-06-26 09:32:18
- date last changed
- 2019-06-26 09:32:18
@misc{8988026,
abstract = {{A prototype invasive (quasi-parasitic) thermal-neutron beam monitor based on isotropic neutron scattering from a thin natural Vanadium foil and standard $^3$He proportional counters has been conceptualized, designed, simulated, calibrated, and commissioned. As the beam monitor is invasive, very low neutron-beam attenuation is a necessary characteristic. Further, response linearity over as wide a range of rates as possible is highly desirable. The prototype was first calibrated using radioactive neutron sources at the Source-Testing Facility at the Division of Nuclear Physics in Lund, Sweden. Subsequently, the prototype was commissioned with beams of neutrons at the V17 and V20 beamlines of the Helmholtz Zentrum in Berlin, Germany. Both low attenuation and response linearity have been successfully demonstrated, indicating the concept is viable and worth continued development efforts. In this thesis, a monographic overview of the development of the prototype is presented.}},
author = {{Maulerova, Vendula}},
language = {{eng}},
note = {{Student Paper}},
title = {{Vanadium-based neutron-beam monitor}},
year = {{2019}},
}