Bladewerx SabreASC™

Alpha Radiation Sample Counter

Features

• Uses an alpha peak-shape fitting algorithm that is more accurate than regions-of-interest or tail-fitting methods of radon background subtraction

• Activity determinations for up to two different radioactive isotopes along with full spectrum logging

• Automatic min-count time determination

• Live “strip chart” display of activity, detection limit, action level, and elapsed time

• User configured display with independently sized windows for activity/status indication, strip chart, and spectral display

• American or SI units

Introduction

The Bladewerx SabreASC™ is a field-deployable alpha radiation sample counter that provides high-sensitivity alpha activity determinations on filters or swipes with real time compensation for radon decay products. Samples no longer need to be stored for several days for radon progeny to decay before being able to assess longer-lived activity. Up to two radioactive isotopes-of-interest can be specified for activity measurement during a count. The SabreASC is easily configured to make activity determinations on most alpha radiation emitting Special Nuclear Materials, and other naturally-occurring radionuclides, and has the unique ability to match an unknown peak to any radionuclide in the user-editable isotope table.

Ruggedized Construction
SabreASC is constructed with a solid metal base plate with interchangeable two-sided sample holders that provide for repeatable sample geometry for 2-inch diameter filters and swipes, or filter cards. The movable upper electronics assembly houses the solid-state ion-implanted radiation detector, detector power supply, amplifier, and multi-channel analyzer. A rugged parallelogram hinge moves the detector in and out of position over the sample and protects the detector face, keeping it parallel to lower plate. On the 2-inch detector model, the detector face is protected by a highly open stainless steel mesh.

SabreASC Assistant Software
The SabreASC Assistant analysis and control software is a Microsoft Windows-based application that provides complete instrument control, calibration, data analysis, and data logging capabilities via the supplied SabreASC cable. The spectrum analysis and separation of radon decay products is possible through the use of Bladewerx’ acclaimed alpha peak-shape fitting algorithm. For simplified energy calibration, the user interface employs simple point and drag operations to position peak locators on the spectral display. Another time-saving feature is the automatic count time determination mode where, based on user-defined action level and confidence bounds, the instrument sample count is terminated as soon as the user-defined constraints are met. The SabreASC Assistant software is included with each SabreASC and can be installed on any Microsoft Windows-based desktop workstation or laptop computer.

Alpha Peak-Shape-Fitting
State-of-the-art alpha peak shape fitting is used to separate the spectrum into the contributions from its constituent nuclides and quantify the spectrum counts from radon decay products and the one or two user-defined isotopes-of-interest. Alpha peak shape fitting is a technique that uses the profiles of multiple alpha radiation isotope peaks to create a composite curve which best fits the actual spectrum counts. Because the individual nuclide peaks are independently determined, the separation of nuclides is impervious to the radon equilibrium state or peak ratio changes during the decay process. Precise fitting of the ²¹⁸Po tail results in excellent resolution of alpha radiation emitters below 5.5 MeV, in many cases allowing the software to resolve ²³⁹Pu from ²⁴¹Am. To learn more about Bladewerx' Alpha Peak Shape Fitting - click here.

The SabrePSC Assistant also includes a “match” mode where each radionuclide in the user editable Isotope List is tested against the spectrum and the isotope with the “best fit” is determined and reported. This feature allows the customer to set the primary isotope-of-interest for the radionuclide of highest likelihood, and let the software test for any other possible activity sources.

Sample Logging and Reporting
The SabreASC Assistant software creates a database of the results of each user initiated count—whether the count completed normally, was cancelled, or finished with an activity above the action level. The database uses the comma-separated-variable (*.csv) format, recognized by most spreadsheet and database software. In addition to the database, at the termination of a count, a hard-copy sample analysis report can be printed.

Specifications

Models

• SabreASC with 1” detector: BIN-SABR-ASC-1

• SabreASC with 2” detector: BIN-SABR-ASC-2

Detector and Sample Holder

• Radiation Detector: Solid-state ion-implanted silicon
     1-inch detector: 450 mm² active area
     2-inch detector: 2000 mm² active area

• Sample Holder: interchangeable holders accept most filters, swipes, smears and planchets to 2” diameter

• Standard 2-inch Sample Holder for filters, swipes, smears and planchets supplied

• Efficiency:
     1-in. detector: 25% (typical)
     2-in. detector with protective mesh: 18%

Data Analysis

• MCA: 1024-channel ADC binned to 256 channel spectrum

• Peak-fitting algorithm for ²¹²Po, ²¹⁴Po, ²¹⁸Po and two additional radionuclides (e.g. ²³⁹Pu and ²⁴¹Am)

• Both fixed, and automatic count time modes

• Automatic Count Time Mode terminates count after activity and detection limit are both below the action level, or if activity is above the action level and reading is within a user-defined confidence level

• Max Count Rate: 600,000 cpm

• Source Response Check diagnostic

• Calibration: Electro-plated stainless steel radioactive source required for efficiency calibration. ²⁴¹Am or ²³⁹Pu recommended.

• Energy Range: 1.0 - 10.0 MeV

Physical

• Weight: 8.8 lbs (4.0 kg)

• Dimensions:
     Closed: 7.3”w x 2.7”h x 14.5”d (19 x 7 x 37cm)
     Open: 7.3”w x 5.4”h x 14.5”d (19 x 14 x 37cm)

•  Temperature: 0 to 122 °F (-20 to 50°C)

• Humidity: 5 to 100% (non-condensing)

• Serial RS-232 Cable supplied

• Power: 12-15 vdc @ 200 mA (AC Adapter supplied, but can be powered by 12 vdc vehicle accessory power)

Options

• SI Units (Bq and Bq/m³): BIN-ASC-OPT2

• Sample Holder for Whatman and NFS/RPS Cards: BIN-ASC-HOLD3

Consumables

• Speclon filters

Spare Parts

• ASCMCA board: BSP-SASC-A1

• RS-232 Null-Modem cable: BSP-CABL-1306

• Detector cable: BSP-CABL-1307

• Detector, 450 mm²: BPT-DETC-SD450

• Detector, 2000 mm²: BPT-DETC-SD2000

• AC adapter/charger (U.S.): BPT-ACADP-1222
   

Technical Information

• SabreASC Data Sheet

• SabreASC Manual

• Bladewerx Alpha Peak Shape Fitting

Other Bladewerx Products

• SabreAlert2 Alpha Radiation Air Monitor

• SabreBZM Alpha Radiation Breathing Zone Monitor

• SabrePSC Portable Alpha Radiation Sample Counter

• SabreBPM Beta Radiation Particulate Air Monitor

• Speclon Filters