Description
Model 5125
The ANTECH vehicle portal monitor Model 5125 makes gamma ray measurements
based on the use of sensitive plastic scintilator detectors and neutron measurements
based on the use of high-pressure He-3 detectors. Portal monitors are designed to detect
radioactive materials and, with neutron detection capability, to detect the presence of plu-
tonium by passive neutron counting. The shielded and collimated plastic scintilator de-
tectors use low noise photo multiplier tubes. In the case of combined technology portals,
the polyethylene moderated high-pressure He-3 detector tubes, providing enhanced neu-
tron detection sensitivity, are connected to high-speed charge collection electronics and
operate in neutron totals counting 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.
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.
Occupancy and speed detection circuits are included in the standard unit. Each control
cabinet contain a battery and charger suitable for a minimum of 12 hours off-line work-
ing. Controllers and warning alarm are active during this period.
The Model 5125 combined technology gamma ray and neutron Vehicle Portal Monitor is
available in the standard configuration or can be re-configured for special applications. A
typical installation consists of two of the assemblies shown on either side of the vehicle
carriageway. ANTECH Portal Monitors are compliant with the requirements of ASTM
C1112-93
Extended versions are available incorporating an extra neutron and gamma detection sys-
tem for very high applications.
Specification
Typical dimensions of twin assembly configuration
·
(L x W x H):
2.5m x 0.5m x 3m (Typically 4.5M separation)
Gamma detectors -- 6 scintillation panels per complete System
·
Neutron Detectors -- 6 neutron horizontal panels each containing 2 He-3 tubes
·
Detection levels (Series 5125):
·
8-10 grams total Pu (military grade)
approximately 1kg highly enriched U
Vehicle transit measurement 0-30km/hr accuracy within 10%
·
Battery back-up
12 hours minimum fully functional including alarms
·
Alarms :
preset values for neutron and gamma counts
·