| |
| |
| |
| |
| |
|
The neutron flux characterization on the microtron MT25
Chvátil, David ; Králik, M. ; Granja, C. ; Krist, Pavel
Microtron is a small cyclic electron accelerator. When it is used as a source of neutrons, electrons must be converted to neutrons by means of nuclear reactions. Spectra of neutrons produced by high energy X-ray photons in lead and uranium targets installed on the microtron MT25 were measured by the Bonner sphere spectrometer with passive detectors of thermal neutrons. Neutron yield from uranium target was nearly two times higher than from the lead one.
|
| |
|
Computing of MT 25 Microtron Dynamic Behavior and Fast Simulation
Krist, Pavel ; Bíla, J. ; Chvátil, David
This paper presents the design of a mathematical model and its fast simulation developed for the setup of the control system of the MT 25 microtron, which is a cyclic electron accelerator. This type of accelerator has been controlled manually until now. The mathematical model is based on calculations of the electron motion in the accelerating cavity and vacuum chamber. The simulation diagram was created in Matlab – Simulink.
|
|
Microstructure Characterization and Faigue Behavior of Beta Phase Containing Gama-TiAl Alloy
Petrenec, Martin ; Beran, Přemysl ; Šmíd, Miroslav ; Chlupová, Alice ; Kuběnová, Monika
The microstructure and fatigue properties of Ti–44Al–7.8Nb – 0.2Ni (at.%) alloy after graded cooling heat treatment were investigated. Different techniques as SEM, TEM and FIB were used for characterization of microstructure. Quantification of phase volume fraction was measured by neutron diffraction method. After graded cooling heat treatment the structure consists of fully lamellar uniform grains which contain lamellar phases /2 and cubic phases (ordered B2 and disordered phases) at grain boundary and interlamellar spaces. The foils for TEM were prepared using FIB technique and observed in TEM in order to identify B2 phase by selected electron diffraction. Low cycle fatigue behaviour at 750 °C shows stable fatigue crack propagation due the presence of plastic beta and B2 phases.
|
|
Quality assurance program for activities according § 59 par. 1
Kubančák, Ján ; Malušek, Alexandr
Work poses document which is necessary a) to obtain the permission from the State Office for the Nuclear Safety of the Czech Republic to provide personal aircrew dosimetry service and b) to realize the service itself for aircrew of the companies registered in the Czech Republic. It is written as a quality assurance program which is based on methodology developed in the NPI for this purpose.
|