Hand-held Detectors Research Articles

Tiered Leak Detection and Repair Programs at Simulated Oil and Gas Production Facilities: Increasing Emission Reduction by Targeting High-Emitting Sources.

Distributions of methane emission rates originating from oil and gas production facilities are highly skewed and span 6-8 orders of magnitude. Traditional leak detection and repair programs have relied on surveys with handheld detectors at intervals of 2 to 4 times a year to find and fix emissions; however, this approach may lead unintended emissions to be active for the same interval independently of their magnitude. In addition, manual surveys are labor intensive. Novel methane detection technologies offer opportunities to further reduce emissions by quickly detecting the high-emitters, which account for a disproportionate fraction of total emissions. In this work, combinations of methane detection technologies with a focus of targeting high-emitting sources were simulated in a tiered approach for facilities representative of the Permian Basin, a region with skewed emission rates where emissions above 100 kg/h account for 40-80% of production site-wide total emissions, which include sensors on satellites, aircraft, continuous monitors, and optical gas imaging (OGI) cameras, with variations on survey frequency, detection thresholds, and repair times. Results show that strategies that quickly detect and fix high-emitting sources while decreasing the frequency of OGI inspections, which find the smaller emissions, achieve higher reductions than quarterly OGI and, in some cases, reduce emissions further than monthly OGI.

Smartphone-Operated Wireless Chemical Sensors: A Review

Wireless chemical sensors have been developed as a result of advances in chemical sensing and wireless communication technology. Because of their mobility and widespread availability, smartphones have been extensively combined with sensors such as hand-held detectors, sensor chips, and test strips for biochemical detection. Smartphones are frequently used as controllers, analyzers, and displayers for quick, authentic, and point-of-care monitoring, which may considerably streamline the design and lower the cost of sensing systems. This study looks at the most recent wireless and smartphone-supported chemical sensors. The review is divided into four different topics that emphasize the basic types of wireless smartphone-operated chemical sensors. According to a study of 114 original research publications published during recent years, market opportunities for wireless and smartphone-supported chemical sensor systems include environmental monitoring, healthcare and medicine, food quality, sport, and fitness. The issues and illustrations for each of the primary chemical sensors relevant to many application areas are covered. In terms of performance, the advancement of technologies related to chemical sensors will result in smaller and more lightweight, cost-effective, versatile, and durable devices. Given the limitations, we suggest that wireless and smartphone-supported chemical sensor systems play a significant role in the sensor Internet of Things.

In memoriam: John R. Mallard (1927-2021).

In memoriam: John R. Mallard (1927-2021).

Dual-modality imaging with a ultrasound-gamma device for oncology

Recently, dual-modality systems have been developed, aimed to correlate anatomical and functional information, improving disease localization and helping oncological or surgical treatments.Moreover, due to the growing interest in handheld detectors for preclinical trials or small animal imaging, in this work a new dual modality integrated device, based on a Ultrasounds probe and a small Field of View Single Photon Emission gamma camera, is proposed.

All Hazards Receipt Facility (AHRF) Testing Algorithm Modifications for Enhanced Screening and Safety

After the terrorist events of 2001, it became rapidly apparent that a comprehensive laboratory detection and response capacity was urgently needed. In the past decade significant work has been done at the local, state and federal level to increase our nation’s emergency response framework. An integral part of this system was the development and construction of the All Hazards Receipt Facility by the Department of Homeland Security. The AHRF is a mobile, selfcontained laboratory designed to screen uncharacterized suspicious substances for chemical, radiological, nuclear, and explosive threats prior to acceptance at a Laboratory Response Network facility, or other testing laboratory. The Wadsworth Centre, New York State Department of Health was one of two sites selected to evaluate the prototype AHRF unit and exercise the testing algorithms for rule out of acute hazards. The original testing algorithm, developed by the Department of Homeland Security and Environmental Protection Agency, has been revised and updated by the Wadsworth Centre’s Biodefense Laboratory. The improved screening protocol enhances the safety of laboratory staff, mitigates hazards that could cause serious damage to the facility and increases public safety. In addition, the modified testing algorithm was developed to streamline sample testing. The changes have significantly decreased result turnaround- times, allow for increased sample throughput thus enhancing workflow. The All Hazards approach to sample analysis requires comprehensive testing of multiple threats with minimal sample destruction to ensure sufficient sample remains for both evidentiary and confirmatory testing. Our screening protocol combines non-destructive handheld detectors and limited sample volume colorimetric test kits to achieve this goal.

Biosensors and bioelectronics on smartphone for portable biochemical detection.

Smartphone has been widely integrated with sensors, such as test strips, sensor chips, and hand-held detectors, for biochemical detections due to its portability and ubiquitous availability. Utilizing built-in function modules, smartphone is often employed as controller, analyzer, and displayer for rapid, real-time, and point-of-care monitoring, which can significantly simplify design and reduce cost of the detecting systems. This paper presents a review of biosensors and bioelectronics on smartphone for portable biochemical detections. The biosensors and bioelectronics based on smartphone can mainly be classified into biosensors using optics, surface plasmon resonance, electrochemistry, and near-field communication. The developments of these biosensors and bioelectronics on smartphone are reviewed along with typical biochemical detecting cases. Sensor strategies, detector attachments, and coupling methods are highlighted to show designs of the compact, lightweight, and low-cost sensor systems. The performances and advantages of these designs are introduced with their applications in healthcare diagnosis, environment monitoring, and food evaluation. With advances in micro-manufacture, sensor technology, and miniaturized electronics, biosensor and bioelectronic devices on smartphone can be used to perform biochemical detections as common and convenient as electronic tag readout in foreseeable future.

Remediating radium contaminated legacy sites: Advances made through machine learning in routine monitoring of “hot” particles

The extensive use of radium during the 20th century for industrial, military and pharmaceutical purposes has led to a large number of contaminated legacy sites across Europe and North America. Sites that pose a high risk to the general public can present expensive and long-term remediation projects. Often the most pragmatic remediation approach is through routine monitoring operating gamma-ray detectors to identify, in real-time, the signal from the most hazardous heterogeneous contamination (hot particles); thus facilitating their removal and safe disposal. However, current detection systems do not fully utilise all spectral information resulting in low detection rates and ultimately an increased risk to the human health. The aim of this study was to establish an optimised detector-algorithm combination. To achieve this, field data was collected using two handheld detectors (sodium iodide and lanthanum bromide) and a number of Monte Carlo simulated hot particles were randomly injected into the field data. This allowed for the detection rate of conventional deterministic (gross counts) and machine learning (neural networks and support vector machines) algorithms to be assessed. The results demonstrated that a Neural Network operated on a sodium iodide detector provided the best detection capability. Compared to deterministic approaches, this optimised detection system could detect a hot particle on average 10cm deeper into the soil column or with half of the activity at the same depth. It was also found that noise presented by internal contamination restricted lanthanum bromide for this application.

금속/비금속 복합센서기반 위험물 탐지기술 개발

Conventional handheld metal detectors use a single induction coil to detect the metallic parts of explosive objects, and the detector generates an acoustic signal from its magnetic response to a metallic object so that an operator can confirm the existence of mines. Though metal detectors have very useful detection mechanisms to find mines, it is easy to cause a high false alarm ratio due to the detection of non-explosive metallic items such as cans, nails and other pieces of metal, etc. Also, because of the physical characteristic of a metal detector it is hard to detect non-metallic objects such as mines made of wood or plastic. Furthermore, the operator must move it to the left and right slowly and repeatedly to attain enough sensor signals to confirm the existence of mines using only a monotonous acoustic signal. To resolve the disadvantages of handheld detectors, many new approaches have been attempted, such as an arrayed detector and a visualization algorithm based on metal/non-metal sensor. In this paper, we introduce a visualization algorithm with a metal/non-metal complex sensor, an arrayed metal/non-metal sensor and the their testing and evaluation.

The Evolution of Neutron Straw Detector Applications in Homeland Security

The dwindling supply of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> He has necessitated the adoption of new technologies for detection of neutrons especially in Homeland Security (HS), where detectors require large volumes of the precious gas. The boron-coated straw (BCS) technology consists of very thin-walled metal tubes equipped with a highly robust coating of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> C on the inner wall. The coating, applied with Physical Vapor Deposition (PVD), is atomically bound to the metal substrate, and it is able to resist delamination over a temperature range from -200 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C to 1000 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C. Accelerated lifetime testing of sealed straw detectors over extreme temperature ranges (-70 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C to +125 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C) have recently demonstrated a 99% expected lifetime of 30 years. At the same time, the coating purity is high, with a <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> B content approaching 77%. Straws stacked 5 deep in a dense array have demonstrated an efficiency of > 70% when evaluated in a cold neutron beam. A number of field worthy HS detectors have been developed over the past 2 years based on the BCS. Examples are presented, including neutron modules for Radiation Portal Monitors (RPM), a vehicle mounted modular detector with an intrinsic efficiency of 30% for unmoderated <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">252</sup> Cf neutrons, and handheld detectors. All of these systems have been government tested. The <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> C coated straw offers a highly versatile, robust and low cost technology meeting multiple needs in homeland and international security.

Detection unit optimization of a neutron searching detector using Monte Carlo Simulations

Abstract The NSD is a portable Neutron Searching Detector developed at Rotem Industries Ltd. with a high efficiency for counting fast and thermal neutrons employing improved gamma rejection. The NSD detection-unit consists of two 3He detectors installed within a polypropylene moderator. The latest international standards for detection of illicit trafficking of radioactive materials require high sensitivity, relatively small dimensions, and light mass. In order for it to meet these standards, the NSD detection-unit was optimized using Monte Carlo N-Particle transport code (MCNP). The moderator mass and dimensions were reduced without deterioration, even improving the instrument's sensitivity. The purposed moderator improvements covered in this paper work well for traditional hand-held neutron search detectors based on 3He tubes as well as for new neutron detection technologies due to the severe worldwide shortage of 3He. Three geometrical moderator configurations were examined using the MCNP code—a rectangular box, a circular cylinder, and an elliptical base cylinder. The optimization results showed that both the rectangular box moderator and the elliptical base cylinder moderators achieve the appropriate sensitivity required by the standards with about 30% reduced mass. A prototype was fabricated with the rectangular box moderator configuration, and its response was successfully validated by comparing empirical measurements against the results of the MCNP code. Performance examination of the optimal detection unit prototype was made regarding the latest international standards. The results showed a 17% improvement in detection limit for radioactive materials along with a 14% to 17% increased neutron detection response, while keeping the false alarm rate below the required threshold, and maintaining a 26% mass reduction.

Measurement evaluations of static and low frequency magnetic fields in the near field region

Manmade electromagnetic (EM) field in the low frequency range of the spectrum, from static to 200 kHz has caused interference with electronic equipment and poses a possible public health risk. Typical sources of these EM emissions include television sets, video display terminals (VDT), electric appliances, fluorescent lights, certain medical devices, walk-through and hand-held detectors, radio stations, induction heating, wireless electricity delivered over distance, hybrid cars and transmission lines. Our main goals for writing this paper are, first, to describe taking measurements of the frequencies and magnetic field levels in residential and occupational environments, particularly around cathode ray tube displays, induction heating units, and hybrid cars; and, second, to compare the measurements to the established or recommended limits according to national standards so that engineers and scientists can understand these nontrivial electrical measurements. The field measurements were carried out using different kinds of devices where a brief description of the instruments used is also provided.

Do Bats Forage Over Cattle Dung or Over Cattle?

Although the importance of cattle grazed pasture to foraging bats has already been well documented, the relative importance of cattle dung compared with the cattle themselves is largely unknown. This was investigated by comparing two adjacent fields: a current and a recent area of organic cattle-grazed pasture in England. The cattle were exchanged between fields during each of two separate observation periods in June and July 2005, one of eight evenings and the other of ten. Hand-held detectors were used to record time-expanded bat passes simultaneously from comparable positions within each field for 150 minutes after sunset. In addition, two separate observation periods (one of three evenings and the other of four) was used to investigate bat activity over and away from cattle within the same field. In general, bat activity was statistically greater within the field containing cattle than in the field without cattle (paired t-test, t21 = 3.97, P < 0.001). Within the field containing cattle, bat activity ...

Measurement of the Activity Per Unit Mass with Hand-Held Alpha and Beta Detectors

This paper describes how to use hand-held alpha and beta detectors to measure volume or mass contamination (Bq g-1) instead of the usual surface activity (Bq cm-2). As a proof of principle, measurements with a hand-held detector of the specific activity of K in potassium chloride yielded the expected result. Field measurements agree well with the results from analytical laboratories.

Test of Radiation Detectors used in Homeland Security Applications

This work was performed as part of the National Institute of Standards and Technology (NIST) program to support the development of the new American National Standards Institute (ANSI) standards N42.32-2003 and N42.33-2003 for hand-held detectors, and personal electronic dosimeters, as well as to support the Office of Law Enforcement Standards (OLES) and the Department of Homeland Security (DHS) in testing these types of detectors for their use by first responders. These instruments are required to operate over a photon energy range of 60 keV to 1.33 MeV and over a wide range of air-kerma rates. The performance and response of various radiation detectors, purchased by the NIST, was recorded when placed in 60Co, 137Cs, and x-ray beams at different air-kerma rates. The measurements described in this report were performed at the NIST x-ray and gamma-ray radiation calibration facilities. The instruments' response (exposure or dose rate readings) shows strong energy dependence but almost no dependence to different air-kerma rates. The data here reported provide a benchmark in support of current protocols that are being developed for radiation detection instrumentation used in homeland security applications. A future plan is to test these devices, plus other commercially available detectors, against ANSI standards N42.32-2003 and N42.33-2003.

Is it safe to work with iodine-131 if you are pregnant? A risk assessment for nuclear medicine staff involved with cleaning and decontamination.

In the UK, Regulation 8(5) of the Ionising Radiation Regulations 1999 (In: Work with ionising radiation. London: HSE Books, 2000) requires employers to ensure that the dose to the foetus of a pregnant worker is unlikely to exceed 1 mSv. Risk assessments are required which are capable of predicting the total foetal dose. Work involving 131I is a particular problem. Foetal dose coefficients from the maternal intake of 131I for all stages of pregnancy have been published (Phipps AW, Smith TJ, Fell TP, Harrison JD. Doses to the embryo/fetus and neonate from intake of radionuclides by the mother. NRPB contract research report 397/2001. Didcot, Oxon.: National Radiological Protection Board (NRPB), 2001. Available on website www.hse.gov.uk/research/crr_pdf/2001/crr01397.pdf), and range from 0.08 microSv x kBq(-1) at conception to 55 microSv x kBq(-1) at week 35. This paper examines one aspect of work in a nuclear medicine department in which the source of 131I is uncontrolled to determine whether the risk assessment indicates that restrictions should apply to a pregnant member of staff. Following in-patient treatment with 131I, rooms are checked and decontaminated before being decontrolled. Cleaning staff were monitored immediately after the cleaning process with hand-held detectors and by whole-body monitoring. Total body contamination ranged up to 3.2 kBq; after a change of clothing, the maximum remaining activity was 0.68 kBq. Acquired contamination correlated with the total activity administered to the patient. Hand-held monitoring rarely detected contamination. Whole-body monitoring indicated that the levels of contamination encountered could lead to a dose limit for the foetus being exceeded. These levels are very difficult to detect with hand-held monitoring. The conclusion to be drawn is that pregnant staff should be excluded from situations in which accidents could arise, or where the source of 131I is uncontrolled or unpredictable.

Field detection and monitoring of explosives

Detection of explosives in situ is of major importance in several applications: finding hidden explosives in airport luggage and in mail; screening of personnel for concealed explosives; environmental monitoring of explosives-contaminated sites; and, detection of buried landmines. Mobile and hand-held detectors have been developed for the various applications. They can be sub-divided into three classes: vapor and particle detectors; radiation detectors; and, biochemical detectors. An overview of the various explosives detectors and their principles of operation is presented.

Metallic orthopaedic implants and airport metal detectors

Airport security can detect in vivo metallic implants. We hypothesized that a soft tissue shield and fast transit through archway detectors would decrease implant detectability, whereas greater implant mass would increase detectability. Twelve patients with 8 orthopaedic implants in vivo and 60 trauma and arthroplasty implants in vitro were subjected to standard airport security measures at Stanstead Airport (British Airports Authority), including arch and standard and nonstandard hand-held detectors. Archway detectors failed to detect some implants; hand-held detectors detected almost all implants except an ankle arthroplasty. Positive archway detection was related to implant transit speed through the detection field. The implant mass consistently affected detection in stainless steel and titanium implants, and a 1-inch wax shield had no effect. Patients with metallic implants should prepare routinely with documentation of their implant before traveling through security ports.

Development of high efficiency, multi-element CdZnTe detectors for portable measurement applications

We describe the development of detector arrays and electronics for large-volume, hand-held CdZnTe detectors with the same counting efficiency as portable NaI(Tl) detectors presently used for nuclear material measurement applications. The pulse-height resolution of the multi-element detectors is at least three times better than NaI(Tl) over a wide energy range (from 100 keV to several MeV), enabling more accurate measurements of gamma-rays emitted by special nuclear material. Arrays of up to eight coplanar grid detectors can be combined to make detectors ranging in size from 4 to 14 cm3. Because the number of spectroscopy channels is small, low-power, hand-held detectors can be manufactured with conventional printed circuit board technology, thus keeping the cost of multi-element detectors to a minimum. The design and performance of an 8-element detector is presented.

Law enforcement tools available at the Savannah River Site

A number of nuclear technologies developed and applied at the Savannah River Site in support of nuclear weapons material production and environmental remediation can be applied to problems in law enforcement. Techniques and equipment for high-sensitivity analyses of samples are available to identify and quantify trace elements and establish origins and histories of forensic evidence removed from crime scenes. While some of these capabilities are available at local crime laboratories, state-of-the-art equipment and breakthroughs in analytical techniques are continually being developed at DOE laboratories. Extensive experience with the handling of radioactive samples at the DOE labs minimizes the chances of cross-contamination of evidence received from law enforcement. In addition to high-sensitivity analyses, many of the field techniques developed for use in a nuclear facility can assist law enforcement personnel in detecting illicit materials and operations, in retrieving of pertinent evidence and in surveying crime scenes. Some of these tools include chemical sniffers, hand-held detectors, thermal imaging, etc. In addition, mobile laboratories can be deployed to a crime scene to provide field screening of potential evidence. A variety of portable sensors can be deployed on vehicle, aerial, surface or submersible platforms to assist in the location of pertinent evidence or illicit operations. Several specific nuclear technologies available to law enforcement and their potential uses are discussed.

Airport metal detectors and orthopedic implants. The responses of arch and hand-held devices.

8 subjects with a variety of orthopedic implants were examined by the security staff at an international airport using arch and hand-held metal detectors. None of the subjects caused activation of the alarm on the arch, although the presence of metal was registered in 2 at a level below the alarm threshold. The hand-held detectors alarmed over the larger superficial implants. A substantial tissue screening effect was noted.