RADEAGLE Technical Manual PDF

Introduction Introduction 1.1 Symbols Throughout this technical manual, the following symbols are used to denote warnings and important information. Indicates a specific danger to yourself or the instrument. Please make sure you carefu...

Introduction Introduction 1.1 Symbols Throughout this technical manual, the following symbols are used to denote warnings and important information. Indicates a specific danger to yourself or the instrument. Please make sure you carefully read these passages. Important information for the instrument usage. 1.2 The RADEAGLE The RADEAGLE is a new generation radio-isotope identification device (RIID). It consists of the following components: Scintillation detector using a sodium iodide NaI(Tl), a lanthanum bromide LaBr3(Ce) or a cerium bromide CeBr3 crystal material Geiger-Mueller detector Optional neutron detector (He-3) Multi-channel analyzer (MCA) for spectral data readout of the scintillation detector Computational subsystem that includes TFT display, keyboard, colored LEDs, vibrator and speaker Battery pack Optional GPS Note: the detector sizes vary for the three crystal materials. The colored detector cap can therefore vary in size, depending on the crystal type. All photographs in this manual are based on the sodium iodide variant crystal. 1.2.1 Detectors Each component has a dedicated purpose. The scintillator is the primary detector of the instrument and would be used for multiple purposes including pulse height analysis and dose rates. 5 Introduction The scintillation detector The scintillation detector is used to collect the pulse height spectrum of the gamma photons that interact with the scintillation crystal. The different radioisotopes each have specific decay schemes and some emit gamma photons that can be analyzed and used to determine the radiation source. Scintillation detector Geiger-Mueller detector The dose rate is determined by either the scintillation detector or the internal Geiger-Mueller tube. When the dose rate at the scintillator surface exceeds 200µSv/h, the Geiger-Mueller tube will perform the dose rate measurement. This tube is suited for measuring dose rates up to 1SSv/h. Geiger-Mueller detector (GM) WARNING. If the Geiger-Mueller detector kicks in, you are already in an extremely dangerous level of radiation. You should increase distance and shielding between yourself and the source. Additionally, you should restrict the time you stay within this field to an absolute minimum. The neutron detector (optional) If your instrument has an optional He-3 neutron detector, this detector will continuously run and acquire the current neutron counts per second (cps). tassium. This material is called naturally occurring radioactive material or NORM). Naturally occurring material (NORM) Naturally occurring materials are potassium 40K, thorium 232Th and uranium ore, which by now has arrived in its radium ground state and consequently is reflected by a radium 226Ra spectrum. NORM constitutes the terrestrial background radiation. Neutron detector 1.2.2 Overview 6 Introduction Figure 1 shows a top view on the RADEAGLE instrument together with short explanations of the most important aspects of the assembly. The RADEAGLE fea presenting the various screens of the software. Three buttons allow you to navigate and handle the software: LEFT, CENTER and RIGHT. The CENTER button also acts as On/Off switch. Four colored light emitting diodes (LEDs) inform you about specific states distinguished by different colors: Gamma Alarm, Neutron Alarm (optional), Charging, Failure. Figure 1: Top view of RADEAGLE instrument. A vibration device is embedded in the handle to give tactile feedback during measurements. It is triggered by detection events in the DETECT MODE and vibrates during alarm states which are programmable by the user. Please refer to the SETTINGS section to learn how the vibrator can be switched on and off. The speaker is positioned directly under the keyboard area. When the system encounters an alarm condition, the speaker will emit acoustic signals indicative of the alarm condition. 7 Introduction 1.2.3 Hardware accessories The RADEAGLE is delivered with comprehensive accessories. The list of accessories may vary depending on what is ordered with the system. When you open the transportation case it should have the following components: RADEAGLE instrument 12V charger USB cable for connecting RADEAGLE to a PC Battery pack Ruggedized suitcase for heavy duty in-field operation 12V power adapter for cars International power adapter plug tip converter Data Transfer box (optional) Carry Strap (optional) Figure 2: The RADEAGLE, inside the transport case with the accessories necessary to operate the instrument. Please make sure the delivered parts are complete. 8 Introduction 1.2.4 Connectors The RADEAGLE has two connectors: 1. The USB connector allows data transfer to and from a computer. All common operating systems like Microsoft Windows, Mac OS X or Linux are supported by this communication port. 2. A power plug for the charger. Please align the red dot to the 12:00 position when inserting the LEMO connector plug. When operating under harsh conditions, keep the connectors clean and free of dust or sand. If you experience connection problems, clean the connector with a cleanser specialized for electronic components. 1.3 User and instrument safety RADEAGLE´s main mechanism for measuring nuclear radiation is based on its scintillation detector. The light of the scintillator is amplified by a photo multiplier tube (PMT) which requires a high-voltage (HV) cascade. A Geiger-Mueller (GM) tube is a secondary detector of the RADEAGLE. This component requires HV. Also, the optional neutron detector (typically a He-3 probe) relies on HV. WARNING. Do not unscrew the housing of RADEAGLE. High-voltage of the interior electronic parts poses a severe health risk for you. It might also cause permanent damage to the instrument. RADEAGLE has only one screw that you are supposed to unfasten which is the security screw that locks the rear side battery hatch. This screw can be turned by hand. No additional tools are required. Precise radiation detection instruments heavily rely on the various detector subsystems. Although the subsystems are internally secured against vibrations or shocks, long-lasting performance of the instrument can be achieved by simply avoiding drops or other strong impacts. 9 Getting started: measuring with RADEAGLE Getting started: measuring with RADEAGLE 1.4 The RADEAGLE user interface layout Figure 3 shows the basic layout of all screens. The STATUS BAR at the top of each screen indicates the battery level, time and the current mode. The MENU BAR is on the bottom of each screen. The menu consists of three fields which correspond to the hardware keys shown in Fig. 4. In this particular screen, the LEFT key corresponds to NEXT, the CENTER key to DOSE and the RIGHT key to SELECT. Pressing the associated key will perform the corresponding action. Figure 3: Fictitious empty screen to explain the MENU BAR and the STATUS BAR. Figure 4: The keyboard, featuring four colored LEDs for visual information. Colors of the keyboard may differ between variants. The keyboard of RADEAGLE is equipped with four LEDs, distinguished by their colors: a blue LED (N) indicates neutron alarm (optional) a red LED (G) indicates gamma alarm a green LED (C) indicates battery charging state and an orange LED (F) indicates a failure (e.g. if the self-test was unsuccessful) 10 Getting started: measuring with RADEAGLE 1.5 Preparations for start-up 1.5.1 Before first start As depicted in the quick START section, before you start the RADEAGLE for the first time, ensure the battery is fully charged. To check this, plug in the provided charger and let it charge until the green LED (see Figure 9) goes off. 1.5.2 Starting the instrument Press and hold down the CENTER button (see Fig. 4) for a few seconds to START the instrument. It begins to boot up when the Neutron Alarm LED and the Gamma Alarm LED (see Figure 1) begin to flash simultaneously. Please note this may take several seconds. Then, after a few more seconds, a startup screen welcomes you, and the system automatically goes into the DOSE RATE MODE (see 2.1.2). The startup screen is shown in Fig. 5. Figure 5: The RADEAGLE booting and startup screen providing the software version and a progress bar. 1.5.3 Batteries The official ORTEC/innoRIID battery pack is a NiMH battery. This NiMH battery can be charged inside the device. As an alternative to this battery pack, a separate battery shell is provided which allows users to use standard AA type batteries. Due to the diversity of battery vendors, ORTEC/innoRIID does not support charging of any third-party batteries while inside the RADEAGLE. Nevertheless, standard AA type alkaline batteries can be used and discarded when drained. Additionally, rechargeable AA batteries can be used, but these batteries must be charged in their appropriate external charger and then reinserted into the battery shell provided. 11 Getting started: measuring with RADEAGLE 1.5.4 Initial Self-Stabilization The primary spectroscopic detector of RADEAGLE crystal produces light pulses whenever gamma photons interact with the crystal material. The light pulses are very weak so they must be amplified. Therefore, the NaI crystal requires a photo-multiplier tube (PMT) which is coupled to the crystal. This assembly allows the incident gamma photons to be digitized by the internal electronics and the pulses (which are proportionate to the energy of the incident gamma rays) form a histogram or gamma spectrum. This spectrum is stored in the embedded multi-channel analyzer. The response of both the NaI detector and the PMT may vary based on measurement conditions such as temperature or magnetic field. The peaks in the gamma radiation spectrum may shift due to these temperature variations. As temperature changes are encountered, modern scintillation based instruments must apply some means of stabilization. Shown below is the procedure the RADEAGLE uses to correct for peak shifts and to adjust the peaks in the spectrum to their scientifically correct positions. Stage 1. Initial stabilization Each time the system is turned on, during the start-up the RADEAGLE performs an initial stabilization. This process takes about 80 seconds. It runs temperature checks and searches for known peaks in the spectrum. It is strongly advised not to have check sources in the immediate area during this initial phase, because this can confuse the process. Stage 2a. Continuous temperature monitoring During the manufacturing process, each RADEAGLE is tested in a climate chamber to learn the individual temperature dependencies of crystal and PMT. Both the absolute value of the temperature as well as the temperature gradients are used in this process. In the field, the instrument continuously monitors and adjust the gain by measuring the temperature. It also distinguishes between slow temperature drifts and quick temperature shocks. Stage 2b. Continuous spectroscopic adjustments Although there is not always an actual source present, the natural background spectrum often contains valuable information. The RADEAGLE uses the natural background peaks for an advanced stage of self-stabilization. When turned on, the RADEAGLE is automatically taking background spectra and analyzing them. All this happens automatically in the instrument, and is completely transparent to the user. Once the RADEAGLE finds known radiation patterns and is sufficiently confident about the analysis result, it uses this information to make an automatic calibration adjustments. In many cases, the most prominent peak to do this is 1460 keV associated with natural potassium K-40. In addition to K-40, there are other peaks (natural and/or non-natural) used by this instrument to create a superior stabilization process. 12 Getting started: measuring with RADEAGLE 1.6 DOSE RATE MODE 1.6.1 Measuring the ambient H*(10) dose rate Once started, the instrument starts up in the DOSE RATE MODE. It shows the ambient H*(10) dose rate in units of µSv/h (this can be switched to mR/h). Consult the chapter SETTINGS for more information. The dose rate is a primary physical quantity measured by the device and indicates the strength of the current radiation field. The count rate is displayed in counts-per- second (cps). Figure 6 shows the DOSE RATE MODE. 1.6.2 Visual guides and alarm annunciation in DOSE RATE MODE A colored bar gives a visual interpretation of the dose rate. It also helps you to qualitatively deduce whether the radiation is strong or not, based on the definitions in the DOSE RATE SETTINGS menu. The green area represents minor radiation strength well below the warning threshold defined in the DOSE RATE SETTINGS. If the dose rate increases, the yellow area would be lit indicating a moderate radiation field. The yellow region corresponds to when the radiation field is stronger than the predefined warning threshold. This will vary based on the level set by the user in the DOSE RATE SETTINGS screen (see Figure 27). Lastly, the red area denotes system is in a dose rate field that exceeds the user defined alarm threshold. Figure 6: The DOSE RATE MODE. Ambient H*(10) dose rate is displayed in units µSv/h or mR/h. Once the dose rate exceeds the warning and alarm thresholds, different visual, tactile, and acoustic alarms will be triggered (assuming the vibrator and sound are enabled in the SYSTEM SETTINGS menu). 13 Getting started: measuring with RADEAGLE 1.6.3 Neutron display in DOSE RATE MODE If the optional neutron detector is installed, the neutron cps will be displayed and a second color bar in blue visually displays the neutron cps. WARNING. Neutron sources are dangerous and neutron sources are always considered as threat! If the instrument indicates the presence of neutron radiation, increase distance to the source immediately. 1.7 Finding radioactive sources with DETECT MODE 1.7.1 Background Finding radioactive sources requires a solid differentiation between the ambient Background dose rate (or count rate) and the dose rate of a potential source. For this purpose, RADEAGLE measures the background as shown in Fig. 7. You can manually trigger the re-acquisition of a new background level with the right button labelled NEW BG. This might become necessary if you changed your measurement location or the background is suspected to have changed for any reason. It is preferable to take the background in a low radiation environment. If you are in a facility with a high natural background or with multiple radiation sources present, the detection capability adapts to this situation. Figure 7. Taking background. 14 Getting started: measuring with RADEAGLE 1.7.2 Finding gamma sources RADEAGLE detects gamma sources by evaluating the incoming radiation strength in terms of count rate. When entering the DETECT MODE, the instrument will automatically perform a background acquisition as described in 2.4.1. It is best to do this in an area representative of the natural background and to make sure no known Rad sources are located nearby. Having established the background, a colored bar graph appears as presented in Fig.8. The bars move from the RIGHT side to the LEFT side of the screen. On the RIGHT side, the most recent bar appears. The height of each bar is proportional to the cps. A color coded scheme aids you to find sources: green bars denote radiation levels close to the background where no additional yellow bars indicate a slight increase in radiation (an additional source might be present) red bars represent increased radiation potentially caused by a source Figure 8: DETECT MODE detecting a source Figure 8 shows the DETECT MODE in a typical situation where the radiation strip chart is close to the background and the background is not varying. The bars are green and may fluctuate slightly which is normal as the radiation is neither constant in space nor in time. The motion of the bars helps you find the location of the source. As the instrument is moved toward a rad source or pointed toward a source, the intensity of the strip chart will increase resulting in peak appearing in the bar graph as the RADEAGLE passes by a rad source. This will be demonstrated in the RADEAGLE training. 15 Getting started: measuring with RADEAGLE 1.7.3 Neutron source detection (optional) RADEAGLE has an (optional) neutron detector installed. If you are close to a neutron source, there are several visual indications that warn or alarm you about it: The blue LED located on the RADEAGLE keyboard will flash when neutrons are detected In the DOSE RATE MODE, the neutron cps will be displayed together with a blue horizontal bar proportional to the number of incoming neutrons In the DETECT MODE, neutron events are marked as blue bars. For tests involving an un-moderated neutron source, an appropriate PMMA phantom or equivalent must be placed between the neutron source and the instrument to accurately simulate the moderation effects of field mission environments (which always provide moderation through surrounding material). 1.8 EASY-ID mode for rapid nuclide identification A primary objective of RADEAGLE is to identify the source of radiation. For performing a quick identification, RADEAGLE features the so-called EASY-ID MODE. In this mode, a time preset (as defined in the SETTINGS menu) is used to acquire a spectrum of the source. 1.8.1 Operation of the EASY-ID MODE The EASY-ID MODE has a visual guidance that helps the user to establish a distance that is favorable for an ID. Figure 9 shows the corresponding graphical user interface on RADEAGLE. There is a prominent graphic in the middle of the screen. The small blue bar indicates whether your position to the source is optimal or not: if you are too close to the source, the bar approaches the upper triangle flanked by the word BACK. You should go BACK to improve the acquisition quality. Similarly, if you are too far away from the source, the bar is near the bottom triangle marked with the word FORWARD. In this case, you should move closer to the source for increasing the quality of the acquisition. If the blue bar is in the middle of the triangles for FORWARD and BACK, the measurement position is optimized, which is denoted by the green line. The EASY ID MODE graphic is surrounded by other measurement information including: a countdown timer is located in the upper LEFT of the screen a display of the dose rate a display of the current count rate 16 Getting started: measuring with RADEAGLE The automatic acquisition will stop, after the timer in the upper LEFT of the screen has counted down to 0. The analysis results will then be displayed. The user can manually trigger an immediate analysis by pushing the ANALYZE button located in the center. Pressing the DOSE button will lead you back to the DOSE RATE MODE. Figure 9: EASY-ID MODE 1.8.2 Nuclide identification result in EASY MODE Once the countdown timer reaches 0, or after the user has pressed ANALYZE, the instrument will display the ID results in a dedicated nuclide ID screen (please refer to Fig. 10). Figure 10: EASY-ID MODE result with Cs137 The result of the identification is composed of following information: Nuclide name in short form, such as Cs137 (please refer to Sec. 4 Nuclide Library for further details) Category: Naturally occurring radiation (NORM), industrial emitter (IND), medical source (MED) or special nuclear material (SNM) Severity: Threat, Suspicious or Innocent which is also indicated via font colors. 17 Getting started: measuring with RADEAGLE Confidence: a number between 1 and 10 that indicates how confident the nuclide identification engine is with its result. By pressing DR-MODE you go back to DOSE RATE MODE. To extend the measurement press CONTINUE. Sometimes, the original measurement time was simply too short or the source is very weak, so extending the measurement time gives additional trust in the result. The EASY-ID MODE features an automatic saving of the spectra and their result. Each spectrum is labelled by a unique date-time identification and an index number. The filename will be indicated in the upper line of the screen. An example is shown in Fig. 10. The filename is printed in blue 2016-01-14T13_16_15_15, which corresponds to a spectrum taken at the 14 th of January, 13 hours, 16 minutes, 15 seconds. The spectrum additionally has the index number 15. You can easily recover your spectra by using the index number. This number makes the spectrum unique and cannot be changed by the user. RADEAGLE always stores two data files in two different formats. For details please refer to page 24 for more about loading and saving of spectra. For the EASY-ID example in Fig. 10, you will find two separate files 2016-01-14T13_16_15_15.spe and 2016-01-14T13_16_15_15.n42 if you download the data onto your computer. 18 ADVANCED MODE ADVANCED MODE 1.9 Entering the ADVANCED MODE This section will show how to personalize the measurement experience with RADEAGLE. To change the SETTINGS of the device, enter the ADVANCED MODE by going through the different modes. Press the CENTER button to leave the DOSE RATE MODE and enter the DETECT MODE. Press the CENTER button again to enter the SPECTRUM MODE and then press the CENTER button which says ADVANCED and the password screen appears (it will not show if a password has not been set up). Figure 11 (Password Screen) To enter the advanced operations mode, type in the default password which is L C R L C. Change your password after the instrument is delivered to prevent unauthorized persons from manipulating the settings. 1.10 The MENU SCREEN of ADVANCED MODE In the ADVANCED MODE the parameters of the instrument can be changed. After entering ADVANCED MODE, a group of buttons allow the user to access the SETTINGS MENUS for specific purposes: changing the SYSTEM SETTINGS, changing the DOSE RATE SETTINGS, changing the DETECT/ID SETTINGS and changing the NUCLIDES SETTINGS. This will be explained in more detail in the upcoming sections. In the SETTINGS section of the ADVANCED MODE, you can also reset the instrument to factory settings by pressing RESET. 19 ADVANCED MODE Pressing ABOUT brings you to an information screen that contains the version numbers. Figure 12: In ADVANCED MODE, buttons lead to specialized settings screens to setup the measurement characteristics, define alarm thresholds and modify the nuclide library. In addition, the ADVANCED MODE provides access to the SPECTRUM MODE and SETTINGS MODE (where key settings may be changed). These modes are typically used by expert users, so they are only accessible under ADVANCED MODE operations (which requires the password). In software version 1.9.5 (or later), the calibration mode has been moved under the SETTINGS MODE. All buttons of the ADVANCED MODE selection menu are shown in Fig. 12. The screen contains a set of small icons that represent the different setting submenus. You can navigate through the icons by pressing the NEXT button. Each time you press NEXT, the icon chosen will have a highlighted background. In Figure 12 above, SYSTEM icon is highlighted in blue. The NEXT button will move the highlight to the SETTINGS icon. By pressing DR-MODE, you can leave the SETTINGS SCREEN and go back to the DOSE RATE MODE. 1.11 SPECTRUM MODE for spectroscopic analysis In the SPECTRUM MODE, you can review and analyze the radiation field spectrum. The instrument can be used as a small portable gamma spectroscopy field laboratory. Use the button NEXT to toggle through the different elements of the bottom menu. Via the button ADV MODE you can go back to the ADVANCED MODE main screen. 20 ADVANCED MODE 1.11.1 Screen layout of the SPECTRUM MODE Figure 13 shows the screen layout of the SPECTRUM MODE. This is basically split into three main areas of information: Green box: A 2D plot of counts (y-axis) versus channels (x-axis) or energy (x-axis). You can toggle between channels and energy, using the button ENERGY or CHANNELS. The plot represents the spectrum of the radiation. Blue box: Data representation (LIN, LOG or SQRT) Length of the spectrum (2048). Redbox: Dose rate (DR) in rem or µSv/h Real/live time (RT and LT) Gamma counts (GAMMA) in cps Gross-counts (GrossC) Dead time (DT) Figure 13: SPECTRUM MODE 1.11.2 Perform a manual acquisition In SPECTRUM MODE the user can perform a spectrum acquisition. The menu bar at the bottom of the screen changes whenever you press NEXT. Navigate through the whole menu to get familiar with the menu structure by repeatedly pushing NEXT. Press START to begin the acquisition and STOP to halt it again. Use the CLEAR button to delete the current spectrum. 21 ADVANCED MODE 1.11.3 Trigger a nuclide identification in SPECTRUM MODE Before, during, and after acquisition, the user can press ANALYZE to perform a nuclide identification on the current spectrum. The nuclide analysis result in shown is the upper right corner of the spectrum screen. Figure 14: SPECTRUM MODE Cs137 was identified The result will stay there until ANALYZE is pressed again. The leading peaks of the identified nuclides are also marked by a flag. WARNING. Radiation sources are dangerous to you! When dealing with nuclear material, you are strongly advised to: 1. Maximize your distance to the radiation source. 2. Minimize the time you are exposed to the radiation. 3. Seek as much shielding between the source and you as any possible. WARNING. In addition to radiation doses from gammas and/or neutrons, certain sources can pose a life-threatening risk to you due to their chemical or biological properties. Plutonium is highly toxic, especially if ingested or inhaled. If RADEAGLE identifies a source as plutonium (as WGPu or RGPu), you should under no circumstances touch the source! 1.11.4 Using the CURSOR The spectrum can be manually evaluated by moving the CURSOR to the peaks. Figure 14 shows the CURSOR on top of an example peak. When using the CURSOR a red text line appears to tell you details about the CURSOR position. In the figure, the x-axis represents the energy. Consequently, the CURSOR position reveals the number of counts located at the specific energy: in the example, in figure 15, 15 counts at an energy of 296 keV is displayed in the middle upper section of the screen. As the cursor is moved, the counts in that channel and energy will change. 22 ADVANCED MODE The position of the cursor line can be switched between energy units or channels by navigating to the corresponding button and pressing CHANNELS or ENERGY. The CURSOR has an automatic acceleration. This allows you to move quickly to high energies and back. When moving the CURSOR to the left side, crossing the zero position, it will wrap around and will place the CURSOR at the high end of the spectrum. Therefore, you can continuously move through the spectrum and the cursor will wrap around when it reaches an end. The CURSOR also sets the initial point for any ZOOM. Figure 15: SPECTRUM MODE using the CURSOR First, use the NEXT button to switch through the button menu until you see the buttons < and >. Here, < is located at the LEFT button and > at the RIGHT button. These two buttons navigate the CURSOR along the x-axis. On the top of the screen you are always informed about the current counts at your chosen channel/energy. Press NEXT to go to the next menu level. 1.11.5 Using ZOOM After a CURSOR is placed on a specific energy, you can ZOOM in on this area. To do this, navigate through the button menu by pushing NEXT until you see a + on the RIGHT button. Press ZOOM IN once to magnify the spectrum at the location of the cursor. If you are in a ZOOM view, you can press ZOOM OUT to leave the zoomed view. 23 ADVANCED MODE Figure 16: SPECTRUM MODE ZOOM at the CURSOR position During ZOOM view, you can still move the CURSOR. Now, the movement of the CURSOR is much finer than in the standard view. The CURSOR acceleration will help you to move quickly to a specific energy/channel. 1.11.6 Loading / Saving spectra RADEAGLE always stores the spectrum in two formats: the IAEA spectrum format SPE and the ANSI N42.42 standardized N42 format. Both formats have advantages. SPE features a simple interface for exchanging spectra and is highly compatible with many international software products. N42 has become the world-wide standard for spectrum files and the list of supporting programs is growing steadily. To store a spectrum press SAVE. To load a spectrum back into SPECTRUM MODE, press LOAD. RADEAGLE can store up to 1 million spectra. Each spectrum contains the associated nuclide identification result. The filename is a unique specifier of the spectrum and is composed of the following date-time configuration: YYYY-MM-DDThh_mm_ss_INDEX. The first part is an ISO compatible date time string. The last number is a unique index that allows quick finding of specific spectra. Each index number is only used once. The spectrum with the number 16, as shown in Fig. 17, can always be recovered by searching for this end number in the filename. 24 ADVANCED MODE Figure 17. Confirmation, that the spectrum was saved. Once you press LOAD, you can restore the spectrum from the internal memory. Press NEXT to navigate through the list of saved spectra. Press SELECT to load the blue marked spectrum file. Via SPEC, you can return to the spectrum at any time. Figure 18 is an example of the selection screen and its buttons. Figure 18: LOAD SPECTRUM 1.11.7 Changing the x-axis: toggling between energy or channel display The spectrum can be displayed using two different x-axis units: a) based on the MCA channels [ch] and b) based on the energy [keV]. The energy-channel ratio of the RADEAGLE scales the energy E=3072 keV to channel 2048 (2k). Internally, the RADEAGLE uses 4096 channels for the spectrum processing. Changing the x-axis scaling also affects the cursor. The instrument will show the cursor position either in channel numbers or energy units (whatever is selected). 25 ADVANCED MODE 1.11.8 Changing the y-axis scaling: linear, logarithmic and square root data representations Scintillation detectors have a certain energy dependent sensitivity. Peaks at low energies (e.g. 59 keV of 241Am) have a higher sensitivity than peaks at the higher end of the spectrum (e.g. 1332 keV of 60Co). When observing this type of spectra and the y-axis has a linear scale, some peaks at higher energies might not be visible. To see a better display of the higher energy peaks, the user may want to look at the spectrum either using a logarithmic scale or a square root scale for the y-axis. These different scales allow the user to visually equalize the peak heights so that a wide range of the spectra can be viewed without zooming. Figure 19: SPECTRUM MODE in SQRT data representation You can choose between three different data representation modes by toggling between LIN/LOG/SQRT. LIN is the normal linear mode of displaying the spectrum. LOG represents the logarithmic view. SQRT is the square root scale for the spectrum. Figure 19 shows a spectrum plotted in square-root scale for the y-axis. The right bar shows an indication SQRT to remind you which vertical scale is currently used. In logarithmic view, the channels with zero counts are mapped to zero. 1.11.9 Toggling between real-time and live-time The MCA component of RADEAGLE is an advanced electronics component that deploys advanced signal processing algorithms for signal interpretation. The MCA and electronics have a short dead- time after each pulse where no signal will be seen. This is because the electronics cannot accept a new pulse to be processed while it is already processing a pulse. The higher the incident count rate, the higher the dead time. The dead-time accumulates with the measurement time and is dependent on the detector load in terms of counts per second (cps). Consequently, two acquisition times may be displayed: the real-time, which is the true time duration of the acquisition and the live-time, which is the acquisition time corrected by the above defined dead- time. The live time will always be shorter than the real time. 26 ADVANCED MODE RADEAGLE allows you to review the real-time and live-time by toggling between them. This can be done by pressing the LIVE button or the REAL button. The dead-time is the time difference between real-time and live-time. 1.12 The CALIBRATION MODE 1.12.1 Source selection Figure 20: Source selection Before entering the CALIBRATION MODE, a calibration source should be selected. By pressing NEXT, you can toggle between the different sources (K- 40, Cs- 137 and Co- 60). To cancel the calibration, just press SETTINGS. 1.12.2 Checking the calibration Figure 21: Calibration check screen for K-40 The calibration has a tremendous impact on the measurement quality of the instrument. It determines the precision of the current calibration by locating the peak at the correct position. RADEAGLE has a dedicated screen to visually inspect the calibration quality when performing a 27 ADVANCED MODE calibration in the CALIBRATION MODE. The CALIBRATION MODE is accessible (the CALIB icon) in the ADVANCED MODE selection menu. On the right side of the display, the following quantities are shown in the CALIBRATION CHECK screen: Nuclide shows the calibration nuclide used for the check Centroid the energy of the photo peak (from standard literature) Measured centroid the centroid of the measured peak (in keV) Measured resolution the resolution given in percentage Measured FWHM the full-width-at-half-maximum (FWHM) The value for the resolution is generated by dividing the FWHM by the measured centroid energy. You can leave the CALIBRATION MODE at any time by pressing the SETTINGS button. This brings you back to the ADVANCED MODE. The procedure for a visual inspection of the calibration when using a 137Cs calibration source: 1. Place a cesium 137Cs1 in front of the detector. 2. Wait until a reliable fit of the peak is established. This can take several seconds. You can identify a good fit when the calculated values show up. 3. The difference between the target value E=661.6 keV of 137Cs and the calculated centroid is the calibration error. The RADEAGLE is a stabilized instrument and it is not expected that the peak positions will drift much. Sometimes a recalibration is still needed because environmental circumstances might be unfavorable for the background stabilization. If you experience unusually high values in the resolution and/or a double peak phenomenon from a single peak source, this could indicate a small crack inside the NaI detector. Please contact the service department. 1.12.3 Re-calibrating using the CALIBRATION MODE The CALIBRATION MODE allows you to recalibrate the instrument. First, perform the visual inspection of the calibration state as explained in the previous section. If you experience a deviation between the target peak position and the actual position, you can perform a manual recalibration. B operative ( Figure 21: Calibration check screen) a 1 137 Cs has a photo peak at the energy E=661.6 keV. It is a popular radioisotope used for calibration purposes. It is available as a sealed button source (check source) from radioisotope suppliers. 28 Operating conditions, technical limits, and tests Operating conditions, technical limits, and tests 1.17 Effective range of measurement Detection and identification depend on the dose rate on the detector surface. This value can be defined by either varying the distance of the source and detector or by simply using stronger or weaker sources. The RADEAGLE measures spectra from 15keV up to 3MeV. 1.18 Determination of the full-width-at-half-maximum RADEAGLE detectors have a specified FWHM, sometimes also denoted as resolution given in percentages relative to their peak position. Our usual reference is the 137Cs peak at 661.6 keV. It is the common peak to specify a resolution. The procedure used to determine this value is given as follows: a) Acquire a background spectrum. b) Acquire a 137Cs spectrum with at least 1µSv/h at the detector surface. c) Use a qualified background subtraction method to subtract the background from the cesium spectrum. d) Perform a Gaussian fit on the peak data (using e.g. Matlab). e) Locate both positions where the Gaussian curve reaches the half of its maximum. f) Calculate the difference in terms of energy. The latter is the FWHM. For sodium iodide based instruments, ORTEC/innoRIID specifies a resolution better than 7.2% at 661.65keV which corresponds to a FWHM of 47.6 keV. 1.19 Determination of full-energy-peak-efficiency 1.20 Explosive atmospheres The internal mounted He3 detector is pressurized with 10 atm. If travelling with the instrument by plane, please respect the IATA regulations. 1.21 Over-range characteristics for the scintillator and the nuclide identification Nuclide identification results depend on the quality of the spectrum. For extremely high count rates, the scintillation spectrum degrades and for dose rates greater than 200µSv/h at the detector surface, RADEAGLE switches off the scintillation subsystem and uses the fall-back GM tube (included in all RADEAGLE variants) for dose rate measurements. 42 Operating conditions, technical limits, and tests A nuclide identification is possible in radiation fields up to 200µSv/h. Though, a valid and precise ID is only given if the limits of the EASY-MODE ID are adhered to. Here, the instrument will clearly indicate, whether an over-range situation exists or not. 1.22 Moisture and dust RADEAGLE fulfills the standard IP65 rating for Ingress Protection of dust and water. 43 Checklist and troubleshooting help Checklist and troubleshooting help 1.23 Checking the proper function of the system To ensure your RADEAGLE is working properly, we will supply a short checklist for successful operation. 1. Check the status of the fault LED a. After some time, the booting screen of the RADEAGLE should appear. If the screen does not appear, check if the display has backlight. If not, there might be a problem with the battery. Power the instrument with the charger or check whether the problem persists. If the instrument boots with power cable connected, check the status of the on/off switch in the rear battery chamber of the unit. b. Is the orange fault LED on? If yes, there might be charging problem or some other problem with the batteries. If it is running, turn the instrument off and try charging the batteries. 2. System boot-up and welcome screen a. Self-checking routines run in the background of the boot process. If a self-check fails, a corresponding error message will appear on the device and give you further advice. b. Once started, the system should welcome you in dose rate mode. If no source is around, the ambient dose rate is expected to be between 0.01µSv/h and 0.08µSv/h. c. The count rate in cps should be greater than 0. There are always natural radiation counts. d. If you have a neutron detector, the neutron cps should be close to 0.00cps. Sometimes values of about 0.05 might occur. If you observe a neutron count rate of 0.5cps or greater, it is likely that a neutron source is nearby. e. If the system was charged, the battery status bar should indicate fully charged status f. If the bar shows a low battery, this might point towards a problem with the batteries. Try charging the battery again. If the problem occurs again, exchange the battery. 3. Specific checks in spectrum mode a. Enter spectrum mode. Without a source, start a spectrum acquisition and observe the area around 1460 keV. After a few minutes, the natural potassium peak should appear at 1460 keV. You can use this peak to verify the correct positioning of the instrument even if no cesium calibration source is available. After fresh startup, the instrument should have at least a precision of around ±0.5% of the line energy or a maximum deviation of ±7 keV around the 1460 keV line. 44 Checklist and troubleshooting help b. After calibration, the instrument should have the potassium 1460 keV line well within ±0.25 (between 1457 keV and 1463 keV). c. Using an external cesium calibration source: Place the source in front of the detector at a minimum distance of 10 cm. Enter calibration check and wait for the threshold sum of the peak counts to be collected. The system will then show you the report of the peak properties. The resolution should not be greater than 7.3%. The peak position deviation should not be greater than 0.5% after startup, corresponding to a shift of ±3.3keV around the target value of 661.6 keV. d. If the peak position deviates, press CAL to calibrate the instrument. Repeat the acquisition of the cesium reference in calibration mode and wait until new values for the peak assessment appear. The peak should be positioned well within 0.2%, ±1.7keV of the target peak position of 661.6 keV. 1.24 Troubleshooting The RADEAGLE was developed using state-of-the-art quality standards for the system architecture and the stability of all components. Nevertheless, it may not be free of mistakes and there might exist situations that were not covered by our quality testing. In the rare event of a crash or a malfunctioning, we compiled a list of possible troubleshooting solutions. 1.24.1 System switches back to Android OS main screen The software was developed for Android OS and if the software crashes, the Android main screen will appear. Solution: Unplug all cables from RADEAGLE will turn black. Wait at least 10 seconds. Put the switch back to the reappears, please contact the ORTEC/innoRIID customer support. 1.24.2 System keeps running although the internal on/off switch is set to off The internal on/off switch activates or deactivates the current flow between battery and main board. If the main board is connected to USB, it will be powered via USB. The system may keep on running for a short time after the battery was removed. Solution: Unplug the USB cable. This will shutdown the power to the mainboard. 45 Technical specification Technical specification Physical properties Weight 2500g, aluminum housing, powder painted Dimensions 248mm x 115mm x 152mm Display 640x480 resolution T rechargeable NiMH batteries, can be charged inside the instrument or with Batteries external charger Operation >8h under standard conditions, backlight off, with GM and He3 time Waterproof 15m (Underwater variant only) Radiological characteristics Spectroscopi c detector FWHM 7.2% or better for 661.6 keV 137Cs at ambient room temperature (for Resolution NaI:Tl) MCA / 2048 channels, 15keV - 3MeV Energy range Sensitivity > 2500 keV 137Cs Calibration Natural background, no internal source required! source Software does allow calibration with Co-60, Cs-137 or K-40 Dose rate 0.01 - 200 µSv/h (Scintillator) up to 1Sv/h (GM tube) range Libraries Default, Medical, Industrial, Special Nuclear Material and On-Site Inspection 46 Technical specification Nuclide library (all) High dose rate Geiger-Mueller-tube detector Neutron He-3 tube detector (optional) detector Computational subsystem Memory > 16 GB = 1,000,000 spectra capacity CPU Speed 1GHz Supported file SPE (IAEA), N42.42 formats Connectivity USB, GPS (optional) PC Software Operating Microsoft Windows (XP, Vista, 7, 8, 10), Mac OS X Yosemite, Linux (tested systems for Ubuntu) 47 Certificate Certificate DECLARATION OF CONFORMITY Radio Isotope Identifying Device (RIID) Type: RADEAGLE Model: All Serial Number: 15001 and up Year of Manufacture: 2015 - Herewith we declare, that the above stated instrument complies with the following EC-Directories: EMC Directive 2014/30/EU Furthermore, the European Standard IEC 61000-4 and the US Standard ANSI N42.34-2006 Complete Listing is included in the technical manual. The above-stated device is defined for the analyzing of gamma radiation. Grevenbroich, 2015-08-27 Peter Henke General Manager 48 Warranty Warranty ORTEC/innoRIID warrants that the items will be delivered free from defects in material or workmanship. ORTEC/innoRIID makes no other warranties, express or implied, and specifically NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. ORTEC/innoRIID found by innoRIID to be defective in workmanship or materials within one year from the date of delivery. ORTEC/innoRIID damages arising out of, connected with, or from the performance or breach thereof, or from the manufacture, sale, delivery, resale, repair, or use of any item or services covered by this agreement or purchase order, shall in no case exceed the price allocable to the item or service furnished or any part thereof that gives rise to the claim. In the event ORTEC/innoRIID fails to manufacture or deliver items called for in this agreement or purchase order, ORTEC/innoRIID to pay the purchase price. In no event shall ORTEC/innoRIID be liable for special or consequential damages. 1.25 Quality control Before being approved for shipment, each ORTEC/innoRIID instrument must pass a stringent set of quality control tests designed to expose any flaws in materials or workmanship. Permanent records of these tests are maintained for use in warranty repair and as a source of statistical information for design improvements. 1.26 Repair service If it becomes necessary to return this instrument for repair, it is essential that Customer Services be contacted in advance of its return so that a Return Authorization Number can be assigned to the unit. Also, ORTEC/innoRIID must be informed, either in writing or by telephone, of the nature of the fault of the instrument being returned and of the model, serial, and revision numbers. Failure to do so may cause unnecessary delays in getting the unit repaired. The ORTEC/innoRIID standard procedure requires that instruments returned for repair pass the same quality control tests that are used for new-production instruments. Instruments that are returned should be packed so that they will withstand normal transit handling and must be shipped via UPS to the designated ORTEC/innoRIID Repair Center. The address label and the package should include the Return Authorization Number assigned. Instruments being returned that are damaged in transit responsibility to make claim with the shipper. Instruments not in warranty should follow the same procedure and ORTEC/innoRIID will provide a quotation for the repair costs. 49 Bibliography 1.27 Damage in transit Shipments should be examined immediately upon receipt for evidence of external or concealed damage. The carrier making delivery should be notified immediately of any such damage since the carrier is normally liable for damage in shipment. Packing materials, bills of materials, waybills, and other such documentation should be preserved in order to establish claims. After such notification to the carrier, please notify ORTEC/innoRIID of the circumstances so that assistance can be provided in making damage claims and in providing replacement equipment, if necessary. Bibliography Sons, 4th Edition Contact ORTEC 801 South Illinois Avenue Oak Ridge, TN 37830 +1 865.482.4411 [email protected] http://www.ortec-online.com/contactus/technicalsupport 50 !' 1 0 1 *+-! %)"* (!-!& *( *.-$ ''%)*%, /! & % #! *+ )-!+) -%*) ' ""% ! * -%*), %,%-.+ ! ,%-!