Functional prototypes and software
LabView code for automatic control of the four-axis manipulator designed for structural studies using nuclear analytical methods
Authors:
Ing. Jiří Novotný, A. Macková, P. Malinský
Annotation:
In the frame of instrumentation development for nuclear analytical methods was installed the sophisticated four-axis goniometer for sample manipulation. Structural studies using nuclear analytical methods need software which enables the automatized procedures of the movements for the finding of the main crystallographic orientations. The goniometer offers the lateral movements in two axes, measuring of the larger set of samples and the rotation around the horizontal and vertical axis. The movements of all four stepper motors can be used in both relative and absolute mode. To determine the absolute position of all axes are used in rotation position sensors and X and Y are used terminal micro switch. Position of all axes is graphically and numerically watched on a computer monitor. Motor movements can be carried out continuously or the movements are realized precisely to the given value with the precision 0.01°. The predefined geometrical arrangements can be used Zero-pos, TOF, ERDA, LOAD-LOCK, and RBS10 Thru and allow approaching the specific measurement position. In the frame of this code is it possible to use the automatized procedures of the crystalline material scanning with simultaneous measurement of the back-scattered ions (RBS) or X-rays (PIXE). Based on this scanning procedure we can find interactively the main crystallographic axis of the investigated crystalline sample and used it for the further structural study. Simultaneously, these positions are monitored virtual LEDs. The program is unique because the manipulator is designed especially for this purpose.
LabView program for surface resistivity measurements of samples
Authors:
Ing. Jiří Novotný, Ing. Pavel Horák, Václav Kučírek
Annotation:
The program is designed for the measurement of the sample sheet resistivity using the van der Pauw method, i.e. the 4-point resistivity measurement. The arrangement is designed for square samples with dimensions 15x15 and 12x12 mm. The program communicates with the switch, power source and voltmeter Keithley and calculates the surface resistance of the samples (see Appendix). The electric current set in the program is driven to 2 adjacent electrodes and voltage is measured on remaining 2 electrodes. The measurement is repeated with reversed polarity. Subsequently, the switch disconnects current setup and connects new set of contacts. The electrical current is driven in the same way and the voltage is measured. All 4 sides of the sample are being measured this way and 8 values of the resistance are obtained. From these values a value of sheet resistivity is calculated.
Automatic measuring system for simultaneous analysis PIXE, RBS, PIGE and PESA on LabWiew base for XIA digital modules Pixie4 and XMAP
Authors:
Ing. Jiří Novotný, RNDr. Havránek Vladimír CSc.
Annotation:
This Lab Wiew computer code enables both fully manual and automatic control over the IBA (Ion Beam Analysis) measurement (mainly individual or simultaneous measurements by PIXE, RBS, PIGE and PESA methods ) in multipurpose target chamber placed on the Tandetron 4130MC ion beam line +30o at INP ASCR. The cod controls adjustments of the samples into the measuring position by means of 4-axis manipulator. It communicates with XIA (Pixie4 and XMAP) digital modules and controls acquisition and visualization of spectra from up to 8 spectroscopic lines . The cod registers ion beam intensity and ion fluences during and after the measurement by means of inner and external beam monitor and check the sample position and condition after the measurement using digital camera. Finally, it controls the archiving of measured spectra and measurement condition in format suitable for subsequent analysis. This measuring system considerably improves and speed up the analysis , storage and arranging of measured data, and simplifies further spectral data evaluation. The cod is suitable, both for the individual sample measurement or for the measurement of large series of samples.
The system of corrective magnets
Authors:
V. Kučírek, J. Novotný, V. Semián
Annotation:
It is a system of corrective magnets with appropriate power source for correcting of the ion beam axis to achieve the optimal beam trajectory for passing through the collimator which axis does not correspond exactly with the geometry of the beam line. By this way it may be optimalized the beam direction into 4 different ion beam lines. Central control is possible from the PC via RS232 serial port.
LabView program for implantation to 12 samples and to center the beam during implantation
Authors:
Ing. Jiří Novotný, RNDr. Vladimír Havránek, CSc.
Annotation:
This is software dedicated for an automatic ion implantation of set of samples as an extension for an implantation chamber commercially manufactured by High Voltage Ltd. In the chamber, there is a manually rotated carousel for 12 samples and four Faraday cups are used for ion current measurements. Automatic sample implantation is realized using a stepping motor connected to the chamber; to indicate the sample in the implant position micro switches are used. The programme (written in LabView, Austin, USA) needs input data: the terminal voltage of the accelerator, ion charge and the required fluence ions/cm2, which is entered into a table for each sample. The programme calculates the implantation parameters for set input data and evaluates its viability as a electrostatic steering of ion beam in X and Y, the number of pulses of the integrator. Further, the program operates the Faraday Cup located in the beamline for the beginning and the end of the implantation. During implantation, the following values are displayed: ion energy, the estimated time of implantation, current (nA/cm2), real counts, implanted fluence (ions/cm2), the time until the end of implantation, the current position of the carousel and the LED display of the sample position. For the event of a shutdown status of the implantation is every minute written into a file. At the end of the implantation is the implantation protocol written into the same file.
For the positioning of the beam over the sample, the programme graphically shows the calculated location of four Faraday cups and determines the geometric centre, to which the sample for the implantation is placed.
This software improves significantly the implantation procedure; saving the processing time of the accelerator during the implantation. It does not require the presence of the operator, thus lowering the costs of the sample implantation.
LabView program for Profile Beam Monitor
Authors:
Ing. Jiří Novotný, RNDr. Vladimír Havránek, CSc.
Annotation:
The functional sample program is expanding the commercial Beam Profile Monitor from NEC Ltd. Originally, the monitor had to be connected to an oscilloscope and it was quite complicated to measure the ion beam profile. The program (written in Labview, Austin, USA) replaced the oscilloscope and the measurement became simpler and clearer. The programme displays peaks in planes X and Y, color-coded quantity of cutting axes X and Y, and the integral spectrum in X and Y.
Since it is not necessary to connect to the oscilloscope, the information about the shape and location of the ion beam is quickly graphically indicated, saving the operator time and the machine time of the accelerators.
Software for the positioning during the irradiation on the external beam
Authors:
Ing. Jan Vitner, M. Davidkova
SW is used for precise positioning of samples exposed to the ion beam radiation in the ambient atmpsphere. There is a positioning device driven by two electromotors, which are controlled by the developed SW. SW allows us to control the positioning device in precision about 0,001 mm in two axis, thus the areal scanning is available. Thus we are able to irradiate the samples, which can not be placed in vacuum conditions (e.g. living cells), with the defined mathematical procedure to cover the requested irradiation area homogeneously by ion beam with maximum beam spot 1 mm2 . We can choose the size of the area exposed to the radiation, to choose the quantity of the radiation (ion fluence) and to achieve uniform radiation of the sample with very low fluencies 104 iontů/cm-2.
The gate of the ion beam
Authors:
Václav Kučírek, Vladimír Havránek RNDr., CSc., Vladimír Semián, Pavel Plocek
Annotation:
It is a source of pulses plus and minus one hundred volts with a very short rising and falling edge (less than 0.2 microseconds). Normally, the output is exactly at zero. Pulses can be of any length. The pulses are fed to the deflection plates. During the deflection the beam does not pass through the ion line but ends on the screens. Actuating: TTL signal.
Indicator of neutron flux
Authors:
Václav Kučírek, Jiří Vacík Ing., CSc.
Annotation:
It is uni-module unit NIM comprising eight highly stable sources of spectrometric pulses with independently adjustable polarity and independently adjustable amplitude from zero to five volts. The device further includes a spectrometric amplifier and the related upper discriminator. From the output of the discriminator the output pulses are synchronized. To synchronize the output pulses is also possible to use external pulses or internal generator.
Internal television system
Authors:
J. Kučírek, J. Novotný, V. Semián
Annotation:
It is a closed television system for distributing signals from many cameras to two output channels, and also on several monitors. The system can be independently controlled from multiple locations including several lines RS232.
Beam Current Measuring System of the Shadowing Shields
Authors:
Ing. Jan Vitner, Václav Kučírek, Ing. Martin Švider, Pavel Plocek, Vladimír Semián
Annotation:
The system is used for the measuring of an accelerator beam of particles. There are four movable shields placed across the beam line in two rectangle axes in all directions. The beam can be falling to each of them by its small part. Each shield can evoke a current flowing between the shield and the developed measuring device. The device is able to measure the current flowing from each of those shields and the device is able to screen measured data by itself or the data could be send to an computer to be screened by a special program, which is an component of the whole developed system. Thanks to this system, we are able to center the beam. The output information is the value of the current flowing from each shield, which represents the value of the charge fallen to the current shield.
