The Mission
Primary screening casts a wide net. A radiation portal monitor at a border crossing, a pager on a patrol officer, or a backpack at a public event will alarm on anything above a threshold. That alarm is a question, not an answer. Secondary screening is where the question gets resolved: an operator with a handheld identifier steps in, takes a spectrum, and determines what set the alarm off and what to do about it.
Most of those alarms are benign. A patient who had a recent nuclear medicine procedure, a shipment of ceramic tile or fertilizer carrying naturally occurring material, a load of granite: all of these trip portals every day. The job of secondary screening is to clear them quickly and correctly, hold the rare genuine threat, and document the decision. When the call is hard, reachback connects the field operator to an expert who reviews the same spectrum remotely. Berkeley Nucleonics builds the instruments and the workflow for both steps.
The Challenge
The core difficulty in adjudication is separating three look-alikes: a real threat, naturally occurring radioactive material, and a medical isotope. A gross-count alarm cannot tell them apart. Only an energy spectrum and an isotope identification can, and the quality of that identification depends on the detector and the algorithm behind it. A weak source, a shielded source, or a mixed field all push an identifier toward an ambiguous result, which is exactly when a confidence-rated answer and a path to expert review matter most.
There is also a documentation and category problem. Identifiers sort results into categories such as special nuclear material, industrial, medical, and NORM, and they assign a confidence level. An operator has to read those categories correctly and know when the instrument's confidence is high enough to act on. When it is not, the workflow has to move the spectrum, the photos, and the location to a reachback analyst without friction. The line below covers the field call and the expert backstop.
Recommended Berkeley Nucleonics Solutions
Secondary screening pairs a fast, accurate handheld identifier in the field with definitive bench spectroscopy and a reachback link for the difficult calls.
Handheld identification and adjudication
The SAM 940+ is the re-engineered handheld RIID built for fast, accurate identification with reduced operator burden. It meets ANSI N42.34 Type C performance requirements, covers 20 keV to 10 MeV with NaI, CLYC, or CLLBC detectors, sorts results into SNM, IND, MED, and NORM categories, and offers one-click reachback over the ANSI N42.42 data protocol. Its solid-state neutron detector adds the channel that flags special nuclear material.
The SAM 945 brings a modern, smartphone-linked interface. Its PeakAbout app manages reporting from a library of 115 isotopes, expandable to 393, reports isotope, category, and confidence, and transmits data in ANSI N42.42 XML. A detachable interface lets an operator stand off from the source, and the unit is compatible with US DOE analysis packages (Cambio, Peak Easy, SAM-Viewer) for downstream review. The ruggedized SAM 950 meets ANSI N42.34, runs NaI, LaBr3, or CeBr3 detectors, and produces an isotope, category, and confidence report with one-click reachback to a RadResponder network, which makes it a strong choice where conditions are harsh.
Definitive spectroscopy
When a handheld result is ambiguous and the call has to be airtight, the Model 970 portable multichannel analyzer provides the deeper look. With up to 4096 channels, a 387-isotope editable library, peak search and identify, and a choice of high-resolution detectors (CeBr3 at about 4 percent FWHM at 662 keV, LaBr3 down to 2.2 percent), it resolves peaks a lower-resolution survey instrument blends together. SNAP-MCA software exports spectra to N42 files for archiving and for an analyst to review. For sample-based adjudication, the Model 971 field analysis kit adds a shielded, calibrated geometry and Food-SSAFE software built around the same Model 970 MCA.
Reachback workflow
Reachback is built into the SAM identifiers. One-click reach back transmits the spectrum, the category and confidence result, appended photos or video, and GPS location in ANSI N42.42 format, and the SAM 950 and SAMmobile platforms are RadResponder enabled for the FEMA network. That puts the field operator's exact spectrum in front of a remote expert, who can confirm or overturn the field call before anyone acts. Compatibility with Cambio, Peak Easy, and SAM-Viewer means the analyst works in standard DOE tools.
Why It Works
Adjudication is a chain of increasing certainty, and this set is built as that chain. The SAM 940+, SAM 945, and SAM 950 give a fast, category-and-confidence answer in the field, which clears the large majority of alarms on the spot. When the field answer is not enough, the Model 970 and Model 971 bring high-resolution spectroscopy and a calibrated geometry to settle the hard cases. And reachback ties the two together, so an expert sees the same spectrum the operator saw.
The shared ANSI N42.42 data format and the compatibility with standard DOE analysis tools are what make the workflow practical rather than theoretical. A spectrum captured on a SAM in the field opens cleanly on an analyst's screen, archives to N42, and feeds the documentation a defensible adjudication requires. Threat, NORM, or medical: the line separates them with identification, not guesswork, and gives a second set of expert eyes when the stakes call for it.
Getting Started
Berkeley Nucleonics can help you stand up a secondary screening and reachback capability, from SAM 940+, SAM 945, or SAM 950 handheld identifiers for field operators to a Model 970 or Model 971 spectroscopy bench for definitive analysis and a RadResponder-linked reachback path. Tell us your alarm volume, your operator skill mix, and your reachback partners, and we will match the configuration.
Call 800-234-7858 or email info@berkeleynucleonics.com. To compare identifiers and review the full set of datasheets and guides, visit the Isotope ID & Radiation Detection documentation library.