In Radlab, basic Radiation Detection Laboratory simulation has been implemented to provide a virtual environment for designing and simulating Radiation Detection and Measurement experiments.
Radiation detection and measurement education is necessary for a wide variety of people working with radiation in two ways. First, they need to know basic concepts of radiation effects to handle radioactive materials safely and secondly to make research in any field related with radiation.
The equipments and laboratory setup needed for delivering this education are expensive and difficult to assemble due to the large variety of the type of experiments that are desirable to cover.
First of all, in a basic laboratory, one needs to have gamma, beta, alpha and neutron sources, at least one detector to detect each type of radiation and other supplemental instrumentation to perform experiments.
Furthermore shielding and a private secured place are needed due to protect people from the effect of these radioactive sources. Nearly two hundred thousand dollars is needed to construct such a basic laboratory described as above.
Radlab, which is a GPL licensed, open source, free software, is a good, inexpensive and easy to use solution for Radiation Detection and Measurement education.
One needs to consider all equipment required for the laboratory before starting modeling part. After that, suitable methods should be selected for detectors, sources and instruments. Monte Carlo simulation method is suitable to model detectors and radioactive sources. There are two main reasons to select Monte Carlo method.
Foremost, it is easy to model heterogeneous geometries. Furthermore, stochastic processes such as radioactive decay and interaction of radiation with matter are easily modeled via Monte Carlo method.
Common detectors used in a basic laboratory can be spitted into types. Gamma detectors in the software are CdZnTe, NaI(Tl)3x3, NaI(Tl)5x5, NaI(Tl)7x7, NaI(Tl)2x2, NaI(Tl)2x2 Well Type, BGO, HPGe, Geiger Muller.
Neutron detectors are BF3 1x7, BF3 3x7. Beta-Pips and Alpha-Pips detectors are modeled as beta and alpha detectors respectively.
So the cross-section data from XCOM [2] is used for gamma interacting materials, and data from ENDF [3] is used for neutron interacting materials. Beta and alpha interaction is basically implemented using stopping power data from SRIM software [4] and NIST database [5].
The environment, in which the experiments are carried on, can be air, water or vacuum. For the environments the cross-section data from the same databases is used. Moreover one needs some shielding material to measure its properties via spectroscopy. An Aluminum shield is also modeled for this purpose.
A collimator is useful which is modeled as pure lead collimator. After the preparation of the cross-section data and modeling via Monte Carlo required for these elements, the basic spectroscopy instruments are modeled.
These are High Voltage Supply for the detectors, Preamplifier and Amplifier for signal handling, Multi Channel Analyzer (MCA) and Oscilloscope to visualize the signals. Additionally, instruments such as Coincidence Unit, Delay Amplifier, Single Channel Analyzer (SCA), Random Pulse Generator and Counter are also modeled.
Radioactive sources are needed for the experiments. Some of the most popular radioactive sources are modeled using decay data from Lund/LBNL database [6].All of the sources are assumed to be isotropic point sources.
The gamma sources Ba-133, Co-60, Cs-137, Na-22 and a mixed source are available. Two neutron sources are Am-Be and Cf-252. Alpha sources are Am-241, Th-230 and Gd-148. Beta sources are Cs-137 and Tl-204.
Working Principle:
The program gives the flexibility to create experiments by choosing from the sources, detectors and instruments, using a simple wizard. Once the user constructs the experiment, the environment in which the experiment would be performed can be selected.
After that the user starts the experiment. For every ten milliseconds the sources in the environment decays via forced decay. The radioactive particles generated from the sources initially penetrate to the corresponding environment isotropically.
While the particles travelling and interacting with the environment, the program checks whether they interact with a detector, material, shield or collimator. When a particle interacts with a detector and deposits some amount of energy, the detector generates a signal on its output.
Then this signal is transferred to the instrument connected to the detector. When an instrument receives a signal it processes the signal and transmits to its output.
The working principles of the instruments are modeled so that they behave like the instruments which can be found in a basic radiation detection and measurement laboratory. When the final instrument is a MCA or Oscilloscope, user sees the output.
Furthermore the program can draw the particle paths while the program is running to give more visual inside of particle interactions. Four type of experiment can be simulated using Radlab. These are gamma experiments. Neutron experiments, alpha and beta experiments.
Conclusions:
To conclude, an inexpensive and easy to use simulation environment for Radiation Detection and Measurement education is implemented. Most commonly used detectors, sources and additional instrumentation are modeled in an extensible way.
Also the computer resource requirements are kept so low that with a modern personal home computer, one can use this software efficiently. So the general cost of the necessary education is lowered to a computer price, which is easily affordable in the current century.
Additionally, in RADLAB one can setup experiments which may be impossible to construct in real life. For example in RADLAB one can make a gamma experiment easily in water, which will be very hard to construct in real life.
Furthermore, RADLAB creates a safe environment for the student, since there is no real radiation risk and also no possible damage risk to the expensive instruments, while learning radiation detection and measurement.
Requirements:
· Java 1.6 or later
