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KVI - Center for Advanced Radiation TechnologyOnderzoek en onderwijsNuclear and Hadron Physics


Projects for Students

A study of three-nucleon forces with BINA

BINA, which is an acronym for Big-Instrument for Nuclear polarization Analysis, is a large-scale detector used in the research of nuclear forces. This device is perfectly suited to study "three-nucleon forces". A famous example of a three-body force can be found in the earth-moon-satellite system. The position of the satellite can be calculated from the sum of the potentials between the individual objects. However, the result of this calculation does not agree with the observed position of the satellite. This is due to the presence of a "three-body force": the gravitational force between the moon and the earth changes the shape of the earth (tides), which, consequently, alters the force between the earth and the satellite. A similar effect has also been observed in nuclear physics, which is known as the "three-nucleon force". The detector BINA has been employed to study this force. Elastic and in-elastic scattering processes of protons with deuterons are studied employing polarized protons or deuterons and the super-conducting particle-accelerator AGOR. The detector consists of a liquid-hydrogen/deuterium target, a multi-wire proportional chamber, and about 200 plastic scintillators. With all these components, the position and energy of scattered protons, deuterons, and neutrons can be determined. At present, the BINA KVI-team consists of two senior researchers, a visitor from Poland, three PhD students, and a master student. Furthermore, work is done in close collaboration with other research groups at KVI and also with international groups from the USA, Japan, and Poland.

Projects with BINA

1) Calibration of the scintillation detectors


The first experiment with BINA took place in November 2005. The acquired data are used to obtain angular distributions and various polarization observables in proton-deuteron scattering. For this, a precise calibration of the scintillators is mandatory. Such a calibration can be done exploiting the experimental data itself. The student will be asked to develop analysis techniques to calibrate the detectors and to apply it to the present data. This work is perfectly suited as a master thesis.


2) Simulations for BINA


Measuring three-body forces with BINA requires a precise knowledge of the detector system itself. This can be obtained by analyzing carefully the experimental data. Furthermore, the results will be compared to a simulation of the reaction channel using a computer model of BINA. Such a model can also be used to study the feasibility of other planned research activities with BINA, for example deuteron-deuteron scattering. The first computer model was made using a Fortran-based simulation package, GEANT3. The student will be asked to implement BINA in a modern, object-oriented, framework, known as GEANT4. Furthermore, he or she will study the feasibility to measure deuteron-deuteron scattering processes by employing the computer model of BINA. This work is perfectly suited as a master thesis.


3) A determination of the wire-chamber efficiency


To obtain angular distributions and polarization observables in the scattering processes studied with BINA, it is mandatory to measure precisely the efficiency of the multi-wire proportional chamber. Data obtained in November 2005 can be used for this purpose. Such a task is suited as short-term project ("korte stage").


4) A new design for the liquid hydrogen/deuterium target


The experiments with BINA are conducted using a liquid-hydrogen or deuterium target. The advantage of such a target is the purity (hardly no background), combined with a high density. However, a disadvantage is the complexity in handling such a target: one has to work with a complex cryogenic system in vacuum. For the planned experiment in 2006, the target cell of BINA will be adapted. The new cell has to be studied systematically in preparation for these experiments. This work is suited as short-term project ("korte stage").

Laatst gewijzigd:28 januari 2014 12:04