Exactly one week a go, Bonphysics B.V. visited the Embassy of the Republic of Kazakhstan, The Hague. Victor was invited to give a presentation about his field of activity and his thoughts about what steps are now needed in this field.
Precies één week geleden bracht BonPhysics B.V. een bezoek aan de Ambassade van Kazachstan, te Den Haag. Victor was uitgenodigd om een presentatie te geven over het werkveld van BonPhysics B.V. en zijn toekomstgerichte ideeën.
Our journey in Norway is continuing as we are asked to build a ‘Van Well Chopper’. Since the 1st of August, 2017, we have been supporting the renewal of the instrument suite of the research reactor JEEP-II at the Institute for Energy Technology in Kjeller. Among other things we provided support during the development of a new reflectometer: FREYJA.
For this occasion we will work together with Reactor Institute Delft to build a neutron chopper. A chopper is needed, to use the TOF (Time Of Flight) method in the FREYA reflectometer to detect the wavelength of neutrons.
The working mechanism of this device is based on cutting a neutron beam into pieces. Hereby small groups of neutrons are created sequentially. Because the distance that is travelled by these groups is known and the time of arrival at the detector of each individual neutron can be measured, the neutrons velocity can be determined, which is inversely proportional to their wavelength. In the picture below, a preliminary sketch of the ‘Van Well Chopper’ can be seen and here an animation of the working mechanism can be found.
Recently, in the 4th edition of a magazine called ‘Innovation media’, about agri innovation and sustainability, an article written by BonPhysics B.V. has been published. This magazine serves as an international agricultural media portal and can be found here. On page 18 you can read our article. It is about the Research & Development cycle and about neglected Science cycles regarding ideas and theories that are not supported (financially) in the Netherlands.
GOOSE, a guard of the cold neutron source, uses the Larmor precision (read more) to check the performance of the cold neutron source. The (cold) neutron source produces slowly moving neutrons that enter the GOOSE apparatus in which the wavelength spectrum is measured. The ratio of the spectrum intensity after and before the installation represents the gain factor, hence the name of the instrument: ‘Gain Of Oyster Spectrometer Equipment’
The Larmor precession, named after Joseph Larmor, is a precession of a magnetic moment of an object in an external magnetic field. An example of such an object is a neutron, a particle that is comparable to a spinning top (read: ‘A new project’) that turns its magnetic moment around a magnetic field. GOOSE actually is built from several components. The neutron beam is defined by two diaphragms (D1 and D2 in the figure). This beam first passes the monitor (M in the figure). In the monitor, the initial intensity of the neutron beam is determined.
Then, it passes the polariser (P) where the neutrons magnetic moment is selected. After the polariser all neutrons that enter the magnetic field (B) have their magnetic moments into the same direction. Since not all neutrons are moving equally fast, the time spent in the magnetic field differs per neutron. After the magnetic field region the neutrons pass the analyser, where they are transmitted or absorbed depending on their magnetic moment. Finally the neutrons that were transmitted are detected (D in the figure). The count rate depends on the direction of their magnetic moment before entering the analyser. All neutrons that are deviating from the ‘set’ direction, will be removed from the beam. The number of turns the neutrons magnetic moment make depend on the magnitude of the magnetic field and the velocity of the neutron, hence by scanning the magnetic field a spectrum of the Larmor frequencies available in the beam will be made.
GOOSE, a guard of the cold neutron source, uses the Larmor precision (read more) to check the performance of the cold neutron source. The (cold) neutron source produces slowly moving neutrons that enter the GOOSE apparatus in which the wavelength spectrum is measured. The ratio of the spectrum intensity after and before the installation represents the gain factor, hence the name of the instrument: ‘Gain Of Oyster Spectrometer Equipment’.
The Larmor precession, named after Joseph Larmor, is a precession of a magnetic moment of an object in an external magnetic field. An example of such an object is a neutron, a particle that is comparable to a spinning top (read: ‘A new project’) that turns its magnetic moment around a magnetic field. GOOSE actually is built from several components. The neutron beam is defined by two diaphragms (D1 and D2 in the figure). This beam first passes the monitor (M in the figure). In the monitor, the initial intensity of the neutron beam is determined.
Then, it passes the polariser (P) where the neutrons magnetic moment is selected. After the polariser all neutrons that enter the magnetic field (B) have their magnetic moments into the same direction. Since not all neutrons are moving equally fast, the time spent in the magnetic field differs per neutron. After the magnetic field region the neutrons pass the analyser, where they are transmitted or absorbed depending on their magnetic moment. Finally the neutrons that were transmitted are detected (D in the figure). The count rate depends on the direction of their magnetic moment before entering the analyser. All neutrons that are deviating from the ‘set’ direction, will be removed from the beam. The number of turns the neutrons magnetic moment make depend on the magnitude of the magnetic field and the velocity of the neutron, hence by scanning the magnetic field a spectrum of the Larmor frequencies available in the beam will be made.
Together
with researchers from the USA and UK, Victor de Haan has submitted a research
proposal regarding gravitation. Gravitation is a force, everyone on the earth
has to deal with. Highly relevant information, such as: the actual source of
origin of gravitation, is still missing. Although several theories about the
origin exist, each one consists of diverse properties.
To discover more about this subject, one has to look at the effects of gravity
on a quantum system. This is what Victor and his colleagues are going to do. An
example of a quantum system is a neutron. A neutron is a very small package and
can be described in different ways: as a particle with mass or as a wave. To be
able to explain what exactly Victor and his colleagues are going to
investigate, a neutron will be compared to a spinning top:
Already conducted experiments on this subject, however not entirely accurate, seem to show that neutrons with a certain spin undergo a less fast acceleration, caused by gravity, than neutrons with an opposite spin. A spinning top can rotate in two directions: left and right (spin) and the gravitation also effects it. Imagine yourself throwing a spinning top in the air while it rotates left and another spinning top, with the exact same properties, while it rotates right. You might observe that the spinning top with the spin to the left, falls back slower to the ground than the one with the spin to the right. If the proposed measurements indeed show that this is the case (with neutrons), some of the existing theories about the origin of gravity become less plausible than others. This will eventually lead to a better understanding of the origin of gravity.
Samen met onderzoekers uit de Verenigde Staten van Amerika en Engeland heeft Victor de Haan een onderzoeksvoorstel gedaan met betrekking tot gravitatie. Gravitatie, beter bekend als zwaartekracht, is iets waar iedereen in het dagelijks leven mee te maken heeft. Zeer relevante informatie over de zwaartekracht, zoals waar deze eigenlijk vandaan komt, ontbreekt nog. Er zijn verschillende theorieën over de oorsprong, en elke theorie heeft weer andere eigenschappen. Om hier meer over te ontdekken, moeten we kijken naar de effecten van de zwaartekracht op een kwantum systeem. En dat is nu precies wat Victor en zijn collega’s gaan doen. Een voorbeeld van een kwantum systeem is een neutron. Een neutron is een mini pakketje en wordt op verschillende manieren beschreven: een deeltje met een massa of een golf. Om verder uit te leggen wat Victor en zijn collega’s met dit mini deeltje willen onderzoeken, vergelijk ik het even met een tol.
Eerder uitgevoerde experimenten, die nog niet heel nauwkeurig waren, zouden laten zien dat neutronen met een bepaalde spin (draaiing) een minder grote versnelling ondergaan door de zwaartekracht dan neutronen met een tegengestelde spin. Als we nu kijken naar een tol, dan kan deze zowel linksom als rechtsom draaien, daarnaast heeft de zwaartekracht ook effect op een tol. Stel dat je die tol in de lucht gooit, met een draaiing naar links, dan lijkt het zo te zijn dat de tol langzamer terug naar de aarde valt, dan eenzelfde tol met een draaiing naar rechts. Indien uit de voorgestelde metingen zou blijken dat dit daadwerkelijk zo is, in het geval van neutronen, dan maakt dat sommige theorieën minder aannemelijk dan andere en wordt meer bekend over de oorsprong van de zwaartekracht.
Recently, BonPhysics has published, in cooperation with IFE (Institute for Energy technology) Norway, an article about thermosiphons. A thermosiphon is a loop in which a medium can flow due to differences in density, differences in height and gravity.
Since 2015, simulations of two-phase hydrogen thermosiphon loops have been developed by BonPhysics for the OYSTER project from the RID (Reactor Institute Delft). Those simulations are applied on the Cold Neutron Source from the IFE in Kjeller, Norway. The obtained results are presented in the article.
However, is this method also usable in other situations? And what about its overall usefulness?
The program is expandable with other materials, temperatures and flowrates, and is useable in a lot of different situations. It is not just applicable to a two-phase loop in a Cold Neutron Source with hydrogen, but for example also to a two-phase loop with boiling water or to a one-phase loop with molten salt. The principle of the calculations remains the same: energy and medium (gas or liquid) transported based on gravity.
The article shows that the simulation of thermosiphons is accurately performed by this program. Hence, the behaviour of the simulated thermosiphons can now be predicted. Firstly, one analyses the behaviour in a known situation by measuring the pressure as function of time. It then becomes clear how the system works and predictions of behaviour in new situations can be made. Or as stated in the article: ‘The modelling and results presented here may be useful for the planning and/ or optimizing of other (CNS) facilities where accurate flow and pressure control, as well as knowledge of void fraction, are important for the correct operation of the facility.’
More information and the accuracy of this new method can be found in the article.
Zeer recent heeft BonPhysics samen met IFE (Insitute for Energy technology) te Kjeller een artikel met betrekking tot thermosifons gepubliceerd. Een thermosifon is een leidingloep waarin een medium kan stromen door dichtheidsverschillen, hoogte verschillen en zwaartekracht.
Sinds 2015 ontwikkelt BonPhysics simulaties van een twee-fase waterstof thermosifon voor het OYSTER project van het RID (Reactor Instituut Delft). In het artikel wordt deze simulatie methode toegepast op een koude neutronen bron van het IFE te Kjeller, Noorwegen.
Maar is de methode ook bruikbaar in andere situaties? En wat is precies het nut van zo’n programma?
Omdat het programma uit te breiden is met nieuwe materialen, andere temperaturen en stroomsnelheden, kunnen vele andere situaties nagebootst worden. Niet alleen een 2 fasen stroming met waterstof in een koude bron kan worden gesimuleerd, maar bijvoorbeeld ook met kokend water of een 1 fase stroming met gesmolten zout. Het principe achter de berekeningen blijft namelijk hetzelfde: transport van warmte en stoffen in gas en/of vloeistof fase gebaseerd op zwaartekracht.
Nu blijkt dat de simulatie nauwkeurig kan plaatsvinden met behulp van dit programma, kan het gedrag van de gesimuleerde thermosifon worden voorspeld. Men kijkt eerst naar het gedrag in een bekende situatie en meet dan bijvoorbeeld de druk als functie van de tijd, dan wordt duidelijk hoe dit systeem werkt en kunnen er voorspellingen worden gedaan over het gedrag in nieuwe situaties. Of zoals het artikel zelf concludeert: het modeleren kan bruikbaar zijn voor het plannen en optimaliseren van andere (koude bron) faciliteiten waarbij accurate stroom en druk regeling en kennis van ‘void fraction’, belangrijk zijn bij het goed functioneren van de faciliteit.
Voor meer informatie en de nauwkeurigheid van deze nieuwe methode, zie het artikel.