ترغب بنشر مسار تعليمي؟ اضغط هنا

Development and characterization of detectors for large area application in neutron scattering and small area application in neutron reflectometry

105   0   0.0 ( 0 )
 نشر من قبل Giacomo Mauri
 تاريخ النشر 2019
  مجال البحث فيزياء
والبحث باللغة English
 تأليف Giacomo Mauri




اسأل ChatGPT حول البحث

Neutron scattering techniques offer a unique combination of structural and the dynamic information of atomic and molecular systems over a wide range of distances and times. The increasing complexity in science investigations driven by technological advances is reflected in the studies of neutron scattering science, which enforces a diversification and an improvement of experimental tools, from the instrument design to the detector performance. It calls as well for more advanced data analysis and modelling. The improvements in resolution, count rate and signal-to-background ratio, achievable with the new instrumentations, also drive the research of alternative technologies to replace the 3He-based detector technology unable to fulfil the requirement of increasing performance. Two solution have been studied: a boron-10-based gaseous detector, the Multi-Blade and a solid-state Si-Gd detector. Both solution are suitable alternatives for neutron detection, able to meet the demands of high performance. It has been shown not only the technical characteristic of the devices, but how the science can profit from the better performance of these new detector technologies in real experimental condition.

قيم البحث

اقرأ أيضاً

MAGIX is a planned experiment that will be implemented at the upcoming accelerator MESA in Mainz. Due to its location in the energy-recovering lane of the accelerator beam-currents up to 1mA with a maximum energy of 105 MeV will be available for prec ision experiments. MAGIX itself consists of a jet-target and two magnetic spectrometers. Inside the spectrometers GEM-based detectors will be used in the focal plane for track reconstruction. The design goals for the detector modules are a spatial resolution of 50 um, a size of 1.20 m x 0.3 m and a minimal material budget. To accomplish these goals we started developing several GEM-prototypes to study different behaviors and techniques to optimize the final detector design. The GEM foils used are provided by CERN and are trained, stretched and framed in our laboratory. The readout is done with an SRS based system. In this contribution the requirements, achievements and the ongoing developments are presented.
The control systems of all neutron scattering instruments implemented by the Julich Centre for Neutron Science (JCNS) are based on Siemens PLC technology. Historically PROFIBUS has been used for the communication of PLCs with supervisory computers, d ecentral periphery systems and other PLCs. Today, PROFINET IO is the most commonly used industrial real time Ethernet system and naturally supported by Siemens PLC systems. As a consequence, all new neutron instruments of JCNS are based on PROFINET IO. For the interfacing to supervisory computers based on CompactPCI, a CompactPCI carrier board for PC/104-Plus mezzanines has been developed, allowing the transparent use of the Siemens PC/104-Plus PROFINET IO controller CP1604 in CompactPCI systems. Linux is used as the operating system for supervisory computers and the software development employs the PROFINET IO-Base-API, commonly supported by Siemens PROFINET IO controllers. On top of this API, an application protocol for the communication with PLC-based motion systems has been implemented.
Neutron reflectometry is a powerful tool used for studies of surfaces and interfaces. In general the absorption in the typical studied materials can be neglected and this technique is limited to the measurement of the reflectivity only. In the case o f strongly absorbing nuclei the number of neutrons is not conserved and the absorption can be directly measured by using the neutron-induced fluorescence technique which exploits the prompt particle emission of absorbing isotopes. This technique is emerging from soft matter and biology where highly absorbing nuclei, generally in very small quantities, are used as a label for buried layers. Nowadays the importance of highly absorbing layers is rapidly increasing, partially because of their application in neutron detection; a field that has become more and more active also due to the 3He-shortage. In this manuscript we extend the neutron-induced fluorescence technique to the study of thick layers of highly absorbing materials; in particular 10B4C. The theory of neutron reflectometry is a commonly studied topic, however the subtle relationship between the reflection and the absorption of neutrons is not widely known, in particular when a strong absorption is present. The theory for a general stack of absorbing layers has been developed and compared to measurements. This new technique has potential as a tool for characterization of highly absorbing layers. We also report on the requirements that a 10B4C layer must fulfill in order to be employed as a converter in neutron detection.
A novel approach is presented to unfold particle hit positions in tracking detectors with multiplexed readout representing an underdetermined system of linear equations. The method does not use any prior information about the hit positions, the only assumption in the procedure is that isolated hit signals generated on consecutive detector strips follow a smooth distribution. Ambiguities introduced by charge sharing from multiplexing are reduced by using a regularization technique. We have tested this method on a multiplexed 50x50 cm$^{2}$ Micromegas detector with 1037 strips and only 61 readout channels, using cosmic rays, and we have found that single and multiple clusters of hits can be reconstructed with high efficiency.
In this paper, the detection efficiency of a large area neutron sensitive microchannel plate detector has been evaluated. A 6LiF/ZnS detector was employed as the benchmark detector, the TOF spectra of these two detectors were simultaneously measured and the energy spectra were then deduced to calculate the detection efficiency curve of the nMCP detector. Tests show the detection [email protected] meV thermal neutron is 34% for this nMCP detector.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا