Another Gamma Spectroscopy Innovation from ORTEC

Transcription

1 ORTEC trans-spec Another Gamma Spectroscopy Innovation from ORTEC High Performance Portable HPGe Gamma Spectrometer REQUIRES NO LIQUID NITROGEN! Rugged, Battery Powered, High-Resolution HPGe Gamma Spectrometer with 16k resolution digital electronics in a single package! 50 mm diameter x 30 mm HPGe detector cooled by miniature, high-reliability mechanical cooler that runs from battery, line power or from an automobile. System performance by patent-pending digital noise filter, which eliminates microphonic noise. Detector element encapsulated in high reliability, low loss, all-metal sealed cryostat. Designed for continuous availability and operation DIGITALLY Stable: consistent answers for long counts, changing count-rates and temperatures Operates With or WITHOUT an attached PC Built-in backlit LCD display and control keypad Live display of acquiring data Energy calibration using keypad Nuclide ID and activity calculation for nine Regions of Interest (ROI) High Throughput over 100,000 processed pulses per second Holds >90 4k spectra in internal memory Fast USB communications. Trans-SPEC is an industry first. For the first time, an HPGe gamma-ray spectrometer with everything you need in a single easy-to-handle package. No need for liquid nitrogen. No long cables... one package, ready to go. The trans-spec concept was born as the ORTEC Detective Portable Nuclide Identifier, * a sister product developed to meet the specific needs of homeland security. Trans-SPEC brings those exciting developments in technology to a more general range of portable gamma-ray applications, including: Nuclear Materials Hold-Up Nuclear Safeguards Inspection In-situ waste assay measurements Emergency response Reactor Maintenance, e.g., corrosion product monitoring Medical Physics... And a host of other applications previously impossible with LN 2 cooled HPGe detectors! * Separate brochure on request.

2 Trans-SPEC HPGe Detector The trans-spec HPGe detector is a P-type ("ORTEC GEM") crystal of dimensions 50 mm x 30 mm of approximately 15% relative efficiency. 1 (This is the only crystal size currently available with the trans-spec). It is cooled by a small high reliability Stirling cooler. The cooler is capable of approximately 1 W of heat lift at 100 K, and draws less than 25 W when operating. A potential problem of mechanical coolers is vibration, which causes microphonic noise on the detector output signal, and degrades the peak resolution. However, by careful mechanical design, and an active digital noise reduction filter (LFR) 2 implemented in the digital spectrometer section of the trans-spec, excellent performance is achieved. Figures 1 and 2 illustrate typical absolute efficiency and resolution for different trans-spec filter settings respectively. Figure 1. Typical Absolute Efficiency for a Point Source at 25 cm. Figure 2. Typical Resolution Upper Curve LFR Off, Lower Curve LFR On. Trans-Spec Display and Keypad Trans-SPEC is entirely computer controllable with the built-in display and numeric keypad for autonomous operation. This high-quality display and easy to use keypad allow the trans-spec to perform a variety of tasks without an attached PC. The trans-spec s built-in, backlit LCD display panel and keypad provide the confidence you need that your data is good. A clear spectral display is provided and start/stop control is accomplished simply by a single keypad entry. The spectral display of the trans-spec is patterned after ORTEC's very successful MAESTRO-32 MCA Emulator, in use on thousands of systems worldwide. A 240 x 160 pixel LCD display allows the user to monitor acquisitions and instrument settings status, with no attached PC. It features a live spectral display with region of interest, peak information and on line activity calculations. ROI's are shown as a bar below the spectrum. 1 ANSI/IEEE Std Performance of Light-Weight, Battery-Operated, High Purity Germanium Detectors for Field Use, R.M. Keyser, T.R. Twomey, D.L. Upp, INMM 44th Annual Meeting, Phoenix, AZ, July 13 17,

3 trans-spec 1 - View Status 2 - Enter ID 3 - Peak Info 4 - MCA Settings 5 - General Settings 6 - Spectrum Memory 7 - Nuclide Report 8 - Cooler Settings Live Time (sec) 10 Real Time (sec) 11 % Dead Time 10 Battery Time Remains 1hr Bias Voltage (Volts) +2000V Fine Gain 0.75 Coarse Gain 5 Rise Time 12.0 Flat Top 0.8 Nuclide kev µci ±% 241Am Cd Co Co Cs Co Co K Tl

4 Real Time Activity Calculations... NO PC Required! Trans-SPEC can also perform nuclide activity calculations using internally stored calibration information, at the touch of a button, and all without the use of an attached PC. Everything is user controlled: the library for analysis, displayed peak labels, unit labels and calibration parameters. They are all easily downloaded by MAESTRO-32 to the trans-spec, and they can be changed in-field to adapt to changing needs. Activity is calculated for the list of up to 9 nuclides. The spectral data can be saved and later re-analyzed in more detail using a more sophisticated PC-based analysis package such as GammaVison-32. Operator Menus All of the trans-spec screens and operations are set using the keypad and the display. The operation is simple select what you want from the displayed list by number and the Enter key. The main groups are: View Status, Enter ID, Nuclide ROI contents, Peak Info, Select ROIs, Select Status contents, Adjust Controls, general settings and View memory contents. The complete list of all functions is given in the specification section. Using the keypad and the display, the MCA settings can be verified or changed in the field without a host computer. The trans-spec is fully integrated with ORTEC software applications such as MAESTRO-32, which can easily download setup parameters. Protection Protection of the data is important, so the MENUS have password protection. The operations are separated into two groups: USER and ADMINISTRATOR. The USER password protects the instrument from unauthorized use. That is, you can protect your data stored in the internal memory. The ADMIN or Setup functions are protected by a different administrator password. The ADMIN functions can only be changed by the Administrator ensuring that your results are based on the correct parameters. SMART-1 HPGe Detector Technology Inside The trans-spec HPGe detector incorporates "SMART-1 " diagnostics. The "state of health" (SOH) function verifies that the detector was operating properly for the entire data collection time. When the acquisition is started, the trans-spec clears the SOH register. During data acquisition, the trans-spec monitors all "vital functions." Should any of the monitored functions fall outside a specified range of values (even if they subsequently return to normal), the condition is registered and at the end of the acquisition the trans-spec reads the SOH and displays a warning message if a problem was detected. No Message no problem. Any CONNECTIONS-32 program, even user-developed packages, may read the SOH register through the trans- SPEC for maintaining the spectrum QA. (Ask for the ORTEC CONNECTIONS-32 brochure.) 4

5 trans-spec Trans-SPEC Power Sources Trans-SPEC can draw power from a variety of sources. The trans- SPEC is designed for "continuous" operation. The miniature stirling cooler has a very long operational life measured in years. For initial cool-down from ambient temperature, the trans-spec is placed on the supplied docking station. It takes approximately 12 hours to cool to operating temperature, once cold, the trans-spec requires only a few tens of watts to sustain it. The internal batteries will give an operation life of >3 hours before additional power support is needed. The optional battery belt can be used to extend the operational period essentially without limit by substitution. An automobile adaptor is supplied to provide charging through the docking station and support while in transit. For mains support and charging, the docking station is supplied with a mains operated DC supply. Trans-SPEC Specifications Internal HPGe Detector Dimensions: 50 mm diameter x 30 mm deep nominal. Coaxial construction. P-type high-purity germanium. Cooler: Hymatic SAX high reliability, low power Stirling Cooler. >50,000 hours lifetime. Dual piston, 1 W nominal lift at 100 Kelvin. Digital Noise Suppression: "LFR Filter." 3 MCA Specifications Display: 240 x 160 pixel backlit LCD provides LIVE spectral display, status information and analysis results. Full Display and Zoom Modes: Display of multiple ROIs. Status Line: User-configurable parameter display. Choice of two from: cursor energy, location, live time, live time remaining, real time remaining, battery life remaining, count rate, count rate in ROI, and counts. The spectral display may be disabled from an attached computer using an administrator function. Energy Calibration: Two point energy calibration of channel and FWHM. On Line Activity Calculation: Activity and uncertainty are calculated and reported on-screen, on-line for up to 9 user-defined regions. Activity is calculated as net count-rate divided by user supplied efficiency factor. Presets: Live time, real time, integral peak count, peak count, uncertainty and Multi-Nuclide MDA. Up to 20 nuclide ROI's may be specified. Acquisition halts when all MDA requirements have been satisfied. Real/Live Time in multiples of 1 sec. Keypad: 20 numeric and function keys. Many of the trans-spec function keys are multi-function. The precise function depends on the context at the time the key is pushed. When the unit is connected to a computer via the USB, the keypad is locked out. Menu Functions Pressing the Menu button while a spectrum is displayed brings up the Main Menu. 3 Patent Pending 5

6 Main Menu Options View Status: Displays all of the major MCA settings,including: Live time, Real time, Dead time, Battery voltage, Bias voltage, Fine gain, Coarse gain, Rise time, Flat top, and Baseline restore [BLR] setting. Enter ID: Entry dialog for a numerical ID included with the spectrum. Peak Info: Reports centroid, FWHM, and net and gross counts for the region identified by the marker position. MCA Settings: Allows adjustment of MCA Controls. 1 - HV Settings 2 - Amplifier Settings 3 - Presets Settings 4 - ADC Settings 5 - Stabilizer Settings 6 - Nuclide ROI Settings 7 - Audio Settings 8 - State of Health Status (read-only) General Settings: Control of instrument access, calibration, and the LCD display. 1 - Change User Password 2 - Change Admin Password 3 - Enter Password 4 - Lock Spectral Display 5 - Auto-Contrast 6 - Calibrate 7 - Display 8 - Status Line 9 - Enable RS-232 Status Line: Sets up the Status Line at the top of the spectrum display to show any two of the following parameters: Cursor location (energy), Cursor location (channel), Live time, Real time, Live time remaining, Real time remaining, Battery time remaining, Count rate, Count rate in ROI, Counts in marker channel.) Spectrum Memory: View and monitor the contents of the trans-spec stored spectrum memory. 1 - Retrieve Stored Spectrum 2 - Erase All Stored Spectra 3 - Spectrum Directory Nuclide Report: Displays a list of predefined nuclides and reports the activity for each. Cooler Settings: Allows user to turn cooler on or off and reports any fault condition. MCA Specifications Maximum System Throughput: >100,000 cps. System Gain Settings Coarse Gain: 1, 2, 4, 8, 16, or 32 Fine Gain: 0.45 to 1 With the available range of gain settings, the following FULL SCALE energy range is achievable 187 kev to ~7 MeV Conversion Gain: The trans-spec conversion gain is software controlled from 512 to 16k channels. Digital Filter Shaping-Time Constants Rise times: 0.8 µs to 20 µs in steps of 0.2 µs. Flat tops: 0.5 µs to 2.0 µs in steps of 0.1 µs with automatic optimization 4 Dead-Time Correction: Extended live-time correction according to Gedcke-Hale method. Accuracy: Area of reference peak changes ±3% from 0 to 50,000 counts per second. Linearity Integral Nonlinearity: <±0.025% over top 99.5% of spectrum, measured with a mixed source. Differential Nonlinearity: <±1%. Digital Spectrum Stabilizer: Controlled via computer, stabilizes gain and zero errors. Temperature Coefficient Gain: <35 ppm/ C. [Typically 30 ppm/ C.] Offset: <3 ppm/ C, with Rise and Fall times of 12 µs, and Flat Top of 1 µs. (Similar to analog 6 µs shaping.) 4 U.S. Patent No. 5,821,533 6

7 trans-spec Overload Recovery: At maximum gain, recovers to within 2% of rated output from X1000 overload in 2.5 non-overloaded pulse widths. (Measured using the InSight Oscilloscope.) Pulse Pile-Up Rejector: Automatically set threshold. Pulse-pair resolution typically 500 ns. Automatic Digital Pole-Zero Adjustment 5 : Computer controlled. Can be set automatically or manually. Remote Diagnostics via Insight Oscilloscope mode. Digital Gated Baseline Restorer 6 : Computer controlled adjustment of the restorer rate (High, Low and Auto). LLD: Digital lower level discriminator set in channels. Hard cutoff of data in channels below the LLD setting. ULD: Digital upper level discriminator set in channels. Hard cutoff of data in channels above the ULD setting. Ratemeter: Count-rate display on MCA and/or PC screen. Trans-SPEC Physical Specifications Maximum Overall Dimensions (including handle, Ge detector endcap and shock absorbers) : 37 cm L x 32 cm H x 16 cm W Weight: 21 lb (9.5 kg) Internal Battery Life: >3 hours at 25 C with a cold detector on fully charged internal battery; battery lifetime may be extended indefinitely by the use of external battery packs which are available in "battery belt" formats. The unit is expected to be kept running once cold. Input Power: V dc 30 Watt or via autosensing Mains powered Battery Charger. Temperature Operation Range/Humidity: 15 C to +50 C, Relative Humidity <90% at 35 C, non-condensing. Communications Ports USB 1.1 connection provided at the rear panel, protected by dust cover. External Power and DC in. Cool Down Time The high reliability cooler is designed for continuous operation. Initial cool down and holding ready for use is normally achived by attachment to the supplied docking station, which may be powered from DC or Mains, and both holds and charges the internal battery. The cooler life is expected to exceed 50,000 hours continuous operation. Initial cool down time depends on ambient temperature, but is typically 12 hours. 5 U.S. Patent No. 5,872,363 6 U.S. Patent No. 5,912,825 7

8 Ordering Information Model trans-spec trans-spec-opt1 trans-spec Description trans-spec integrated HPGe spectrometer system, complete with docking station, universal mains supply and charger, USB cable, automobile cable, USB cable for laptop connection, and MAESTRO-32 Software. Battery Belt to extend operation life. Specifications subject to change ORTEC Fax (865) South Illinois Ave., Oak Ridge, TN U.S.A. (865) For International Office Locations, Visit Our Website ADVANCED MEASUREMENT TECHNOLOGY