ANTECH portal monitors are available in two basic configurations, Gamma ray measur-

ing based on the use of sensitive plastic scintilator detectors and combined gamma ray

and neutron measuring, again using sensitive plastic scintilators but combined with high-

pressure He-3 detectors.  The portal monitors are designed to detect radioactive materi-

als and, with neutron detection capability, to detect the presence of plutonium by passive

neutron counting. The shielded and collimated plastic scintilator detectors use low noise

photo multiplier tubes, with state of the art digital detection electronics based on ORTEC

digiBASE.  In the case of combined technology portals, the polyethylene moderated

high-pressure He-3 detector tubes, providing enhanced neutron detection sensitivity, are

connected to high-speed charge collection electronics and operate in neutron totals count-

ing mode.

ANTECH portal monitoring technology is derived from work performed at the Los Ala-

mos National Laboratory (LANL) and implemented in the late 1980's by Jomar Systems.

Since the transfer of technology to ANTECH, extensive improvements have been added

and the ANTECH portal monitoring technology represents the current state of the art.

ANTECH continues to work with technology developers at Los Alamos who are engaged

in a process of continuing improvement with a view to optimising the performance for

Homeland Security and defence related applications.

The operation of ANTECH portal monitors is automated through the use of an onboard

microprocessor controller, which performs system diagnostic testing, input monitoring

and background discrimination. The controller employs algorithms based on the sequen-

tial probability ratio (SPR) test, developed originally by Fehlau and others at LANL.

The portal monitors contain all the necessary electronics, including controller, power

supplies, amplification, single channel analyser and high voltage bias supplies to consti-

tute stand alone instruments.

The Series 5103 gamma ray and the Series 5105 combined technology gamma ray and

neutron Pedestrian Portal Monitors are available in the standard configuration shown

with twin vertical pillars. It is also available without detectors in the bottom (floor) unit.

The ANTECH Pedestrian Portal Monitors are compliant with the requirements of ASTM

C1112-93 and the units follow the guidelines ASTM C1189-95 for calibration and

ASTM C993-92

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(L x W x H):

680mm x 140mm x 2200mm (each pillar)

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0.4 grams total Pu (military grade)

approximately 10 g highly enriched U