Gamma Spectrometry Research Articles

The rapid synthesis of 1,10-phenanthroline-5,6-diimine (Phendiimine) and its fascinating photo-stimulated behavior

Here, for the first time, we report synthesis of 1,10-phenanthroline-5,6-diimine (Phendiimine) based on an acid catalysed SN2 reaction of 1,10-phenanthroline-5,6-dione and 2-picolylamine in EtOH as a solvent. The synthesized Phendiimine molecule showed excellent photo-sensitivity against visible light, together with photoluminescence in both water and ethanol and also, it showed electrochemical activity with Fe electrode in ethanol and H2SO4 solution. Tauc plot also showed Phendiimine is a direct band-gap semiconductor. The hot-point probe test also showed that it is a n-type semiconductor. The UV–vis. absorption maximum shift in two solvents (water and ethanol) demonstrates the solvatochromism behavior of the molecule. The practical significance of this work and its guiding implication for future related research can be outlined as follows. Based on the results obtained, it appears that the Phendiimine molecule could revolutionize the medical field, potentially in the design of artificial eyes, increasing the yield of photovoltaic cells through enhanced heat transfer, improving computers and industrial photo-cooling systems, serving as photo-controller in place of piezoelectric devices, functioning as electronic opt couplers, controlling remote lasers, changing convection in photothermal heaters, designing miniaturized real photo-stimulated motors, creating photo or thermal switches through spin crossover complexes, developing electronic light-dependent resistance (LDR) devices, constructing X-ray and gamma-ray detectors, designing intelligent clothing, creating photo dynamic tumour therapy (PDT) complexes, singlet fission materials in solar cells and more.

3x3 array module of 8×8×32 mm3 position-sensitive virtual frisch-grid CdZnTe detectors for imaging and spectroscopy of cosmic gamma-rays

We evaluated the performance of the 3 × 3 array of 32-mm long position-sensitive virtual Frisch-grid (VFG) CdZnTe (CZT) detectors read out by the IDEAS GDS-100 data acquisition system. The array is a mechanically solid module designed for integration into a large effective area gamma-ray telescope proposed for imaging and spectroscopy of cosmic gamma-rays. The array employs the bar-shaped 8 × 8 × 32 mm3 CZT crystals which recently became available from Redlen Technologies, Inc. and Kromek-eV Group PLC at affordable costs. The waveform sampling IDE3421 application-specific integrated circuit (ASIC), developed by the University of Michigan and IDEAS for CZT pixel detectors, was adapted to capture the signals from the array's VFG detectors. We showed good spectral performance of the Redlen detectors with an energy resolution of <1% FWHM at 662 keV and slightly poorer performance of the Kromek-eV detectors with a resolution of <2% measured at a reduced temperature of 13 °C. By testing the same detectors as single devices using hybrid charge-sensitive preamplifiers, we demonstrated improved energy resolutions at a normal temperature of ∼25 °C: <1% and 1.3–1.7%, respectively. However, the Kromek-eV detectors did not perform as well as the Redlen ones. We explained this by the space charge formation (polarization) decreasing the electric field and the electron drift times. The polarization was likely caused by the high injections of holes from the anode contacts. The absence of polarization in Redlen detectors suggested that the quality of the contacts might have played a role in this case.

A Monte Carlo simulation study for designing collimators for a CZT-based spent nuclear fuel characterization system

As an attempt to develop a spent nuclear fuel characterization system that can acquire both high-resolution gamma-ray energy spectrum and neutron flux simultaneously at multiple positions around the spent nuclear fuel assembly and provide more information compared to conventional equipment, simulation study was conducted to design a collimator around a gamma-ray detector to obtain high-resolution gamma-ray spectra in a high-flux gamma-ray environment. The ORIGEN depletion code was used to evaluate the source terms of spent nuclear fuel, and MCNP 6.2, the Monte Carlo simulation code, was used to simulate the detector response. Considering the realistic operating conditions of Korea's pressurized light water reactor, the source term for the ACE7 17×17 nuclear fuel assembly was derived under the conditions of initial enrichment ranging from 3 to 5%, burnup ranging from 30 to 60 GWd/MTU, and maximum cooling time of 30 years. MCNP 6.2, the Monte Carlo simulation code, was used to design a spent nuclear fuel characterization system using a CZT detector as a gamma-ray detector to obtain a high-resolution gamma-ray energy spectrum. In particular, the research focused on designing collimators to be used in high-flux radiation environments, such as spent nuclear fuel inspection, with CZT detectors. A simulation model of the CZT detector to be installed internally was made and the validity of the detector simulation model was confirmed by comparing simulation results with the measurement experiment results. Finally, the response of the CZT detector was calculated by changing various setting parameters of the collimator. By comparing the calculated detector response with the design standard count rate, the design of a collimator that can utilize the CZT detector in a spent nuclear fuel inspection environment was derived.

A Wireless Gamma-Ray Monitoring System for Cemented Radwaste Drums.

In the framework of the PREDIS EU project, a wireless battery-operated gamma-ray detection system was developed in order to provide a medium-to-long-term monitoring system for radioactive waste drums. It was initially proposed to monitor the gamma radioactivity outcoming from steel drums containing cemented radwaste, even though it could be usefully employed in a wider range of applications. Gamma rays are penetrating and convey information from the drum's internal structure, as the count rate measured on the surface depends on the thickness and density of the crossed materials. A number of sensors arranged around a drum, typically four units, provide indications of the emission anisotropy, and any sensitive change in the measured count rate would hint at some anomaly, thus triggering a suitable inspection by operators.

Activity concentration of NORM at reclaimed ex-coal mines in South Sumatra, Indonesia

Unbeknownst to us, natural radiation is in close proximity to human existence. Post-mining practices can generate naturally occurring radionuclides that have the potential to cause radiological effects on human health. This study utilized soil samples obtained from ex-mining reclamation land in Banko Barat, South Sumatra Province, to assess the concentration of natural radioactivity and the corresponding radiation dose. Eight composite soil samples were collected from reclaimed land. The samples underwent processing and analysis through gamma spectrometry in order to ascertain the activity concentration of the radionuclides 226Ra, 232Th, and 40K. The RESRAD-ONSITE 7.2 software utilizes the activity concentration of soil samples as an input parameter to accurately predict the dose rate for workers. The projected dose rate was determined by considering four routes of exposure: external gamma radiation, inhalation, radon, and ingestion of soil. The measured activity values of soil samples from reclamation land for 226Ra ranged from 25.6704 ± 0.5082 to 58.8555 ± 0.6917 Bq/kg. The activity values for 232Th ranged from 30.5546 ± 0.1757 to 42.53020.3004 Bq/kg. Lastly, the activity values for 40K ranged from 533.902 ± 6.4023 to 988.081 ± 9.6948 Bq/kg. The total effective dose rate measured in the reclaimed land falls between 0.08673 and 0.1469 millisieverts per year. The value does not surpass the maximum limit set by BAPETEN, which is one mSv/year. Therefore, no additional protective measures are required for workers.

Prototyping of a Machine Learning–Based Burnup Measurement Capability for Pebble Bed Reactor Fuel

The pebble bed reactor is a unique reactor design due to its capacity for continuous multipass circulation of the fuel elements, without causing interruption to reactor operation, with the assistance of the burnup measurement system. Such a system necessarily requires an accurate knowledge of the burnup of each fuel pebble upon ejection from the core so as to inform the reloading decision and to ensure that no pebble exceeds the regulated discharge burnup limit at any point following reinsertion into the reactor core. In this work, we conceptualize, develop, and demonstrate a machine learning–based fuel burnup prediction framework leveraging advanced modeling and simulation capabilities. At its core, machine learning regression models are learned from simulated data to establish the correlation among the irradiated fuel composition (hence burnup), the gamma leakage spectrum, and the gamma spectroscopy results. Sensitivity analysis is conducted to quantify the impact of unknown design parameters, such as fuel enrichment, and irradiation environment, including power density, temperature, and neighboring materials, on the prediction accuracy of various supervised regression algorithms. The effects of a short cooldown period on machine learning prediction accuracy are also investigated. A test data set is used to validate that the data generation methodology proposed in this work successfully results in a machine learning model capable of interpolating its prediction of burnup onto a much wider range of irradiation conditions than were explicitly represented in the training database. The inclusion of a cooldown period of just 2 h leads to a prediction root-mean-square error of <5 MWd/kgU when the fuel enrichment is known and <9 MWd/kgU otherwise.

LISA and LISA-like mission test-mass charging for gamma-ray burst detection

Cubic gold-platinum test-masses (TMs) play the role of free-falling geodesic reference and interferometer end mirrors of the future Laser Interferometer Space Antenna (LISA) observatory for low-frequency gravitational wave detection in space. A similar arrangement has been proposed for the Chinese missions Taiji and TianQin and for the LISA follow-on missions such as ALIA and BBO. The TMs are charged by high-energy particles and photons. The deposited charge couples with stray electric fields surrounding the TMs thus inducing spurious forces that limit the sensitivity of the mission mainly at low frequencies. The TM charging was measured in space in 2016-2017 with LISA Pathfinder (LPF), meant for the testing of the LISA instrumentation. Unfortunately, during the time LPF remained in orbit, no solar energetic particle events or major astrophysical phenomena were observed. We aim at estimating the LISA TM charging attributable to long, short gamma-ray bursts (GRBs) and magnetar flares in comparison to that of charged particles of galactic and solar origin. The contribution of these major astrophysical phenomena to the LISA TM charging is discussed here for the first time. The results found here can be extended to LISA-like missions. The response of the radiation monitors hosted on the three LISA S/C is also evaluated. We show that long, intense extragalactic GRBs and galactic magnetar flares at kpc distances can be detected and monitored through a sudden change from positive to negative charging of the TMs and an increase of the TM charging noise. This is a unique signature since both galactic and solar particles charge positively the LISA TMs. This peculiar behavior of the TM charging would allow monitoring the whole dynamics of GRBs. The suggestion reported in the literature, about the detection of long GRBs and gravitational waves from the same sources, in principle, may apply to LISA and other LISA-like missions since the increase of the TM charging noise during these extreme transient phenomena is estimated to remain below the mission sensitivity while particle detectors are expected to saturate.

Gamma-ray spectrometry, magnetic and gravity signatures of Archean nuclei of the Borborema Province, Northeastern Brazil

Gamma-ray spectrometry, magnetic and gravity signatures of Archean nuclei of the Borborema Province, Northeastern Brazil

Modeling gamma detectors in OpenMC: Validation of a newly implemented pulse-height tally

Gamma spectroscopy measurements can be simulated using a pulse-height tally functionality of Monte Carlo particle transport codes. Such a functionality must account for the complete simulation history of a particle’s energy deposited in a particular volume. OpenMC, an open-source application for neutron and photon particle transport which is widely used in the nuclear engineering community, previously lacked adequate simulation capabilities for gamma spectroscopy. In this paper, we outline the implementation of the photon pulse-height tally for OpenMC. Additionally, we validate the new function by comparing results to analytical calculations, other software, and experimental data.

Use of a drone-based gamma-ray spectrometry system to assess point or extended radioactive sources

In recent times, the utilization of unmanned aerial vehicles (UAVs) has emerged as a novel tool for a wide range of tasks associated with radiological protection in hazardous situations. This article presents the development of a rotary-wing drone-based system equipped with a LaBr3(Ce) detector, enabling highly accurate quantification of both point and extended radiation sources. The drone’s capability to precisely measure H*(10) and the activity levels of the involved radionuclides has been assessed through real-world testing in two scenarios. The results demonstrate uncertainties of less than 20%.

The use of in situ Gamma-Ray Spectrometry to Assess the Environmental Impacts of Intensive Agriculture in terms of Geochemical Mobility in soil and waters

The concentration and mobility of metals in the lithosphere and hydrosphere are led by many physical-chemical parameters and processes from natural and anthropogenic origins, the last one resulting in impacts over many ecosystems around the World, including wetlands. These transitional zones, often characterized by the presence of hydric soils, adapted vegetation, and seasonal or permanent presence of surface water, are commonly under human pressure in terms of land use conversion and contamination, notably in agricultural production areas, where excess of nutrients/organic matter, pesticides, salts, sediments, heavy metals and radionuclides (originated from inorganic fertilizers) can substantially alter the ecological balance of those ecosystems. Thus, this study aimed to evaluate the agricultural impact over a tropical geographically isolated wetland in the Brazilian Cerrado by the analysis of geochemical mobility and interaction between surface and groundwater through in situ gamma-ray spectrometry and hydraulic conductivity measurements. The results demonstrated that the margins of this diabase-derived soil wetland are one of the most important and critical compartments due to its capacity of metal immobilization and surface water infiltration, indicated especially by uranium concentrations. Thorium, in turn, was most related to colluvial transport from slopes to the center of wetland. It was also corroborated by low hydraulic conductivity zones as a result of soil compaction due to heavy agricultural machinery and increase in runoff fluxes. Thus, this methodology could be used as an initial fast screening method in wetlands under other climatic and geological/pedological contexts to evaluate the local hydrogeochemical dynamics and impacts of agricultura.

Inference of minerals at Redondão kimberlite crater, Parnaíba Basin, Brazil, based on interpretation of airborne gamma-ray spectrometry and ASTER data

Inference of minerals at Redondão kimberlite crater, Parnaíba Basin, Brazil, based on interpretation of airborne gamma-ray spectrometry and ASTER data

Design of low-cost digital pulse processing unit for gamma spectrometry

Gamma spectrometers are used to quantify and identify radioisotopes in the sample under test. There is a recent interest around the world in implementing low-cost gamma spectrometers. One of the main parts of the modern gamma spectrometer is the digital pulse processing unit (DPP). The implementation of this unit using advanced microcontroller chips has appeared in recent years as an attractive approach. This is due to its advanced performance and low cost. In this paper, we present a design flow to implement a DPP unit using an ARM Cortex-M3-based microcontroller chip. The sodium iodide detector is the targeted detector for this design. Our prototype is approved experimentally to construct spectrums comparable to commercial devices. And it can cope with input count rates up to 45 kC/s.

Gamma-ray detection of newly discovered Ancora supernova remnant: G288.8–6.3

Context. The supernova remnant (SNR) G288.8–6.3 was recently discovered as a faint radio shell at high Galactic latitude using observations with the Australian Square Kilometre Array Pathfinder (ASKAP) in the Evolutionary Map of the Universe (EMU) survey. Aims. We performed the first detailed investigation of the γ-ray emission from the G288.8–6.3 region, aiming to characterise the high-energy emission in the GeV regime from the newly discovered SNR, dubbed Ancora. Methods. Fifteen years of Fermi-Large Area Telescope (LAT) data were analysed at energies between 400 MeV and 1 TeV, and the excess seen in the region was modelled using different spatial and spectral models. Results. We detect spatially extended γ-ray emission coinciding with the radio SNR, with detection significance up to 8.8 σ. A radial disk spatial model in combination with a power-law spectral model with an energy flux of (4.80 ± 0.91) × 10−6 MeV cm−2 s−1, with the spectrum extending up to around 5 GeV was found to be the preferred model. Morphologically, hotspots seen above 1 GeV are well correlated with the bright western part of the radio shell. The emission is more likely to be of leptonic origin, given the estimated gas density in the region and the estimated distance and age of the SNR, but a hadronic scenario cannot be ruled out. Conclusions. Ancora is the seventh confirmed SNR detected at high Galactic latitude with Fermi-LAT. The study of this new population of remnants can provide insights into the evolutionary aspects of SNRs and their properties, and further advance efforts of constraining the physics of particle diffusion and escape from SNRs into the Galaxy.

Evaluation of Radon Concentration in Soil Sample from Boreholes in Kaltungo Local Government Area of Gombe State, Nigeria

The evaluation of radon concentration in soil sample from boreholes in Kaltungo local Government area of Gombe state, Nigeria have been carried out. A total of fifteen (15) soil samples were collected from different boreholes sites in five (5) different locations and were analyzed using Gamma spectrometry (Sodium Iodide with thallium NaI (TL) detector. The mean result of Radon activity concentration obtained varies from 0.86± 0.05 to 1.71± 0.03 Bqm-3 and the annual effective dose rate ranged from 0.0039 to 0.0077WLm/y respectively. The result shows variations in the radon concentration with various depths which indicates a relative dependence of radon concentration with depths. Comparing the results with the WHO recommended value of 100 Bqm-3 indicate that the mean values for all the boreholes soil samples were below the world recommended value. Also the mean values for all the boreholes soil samples were below the world average radon concentration of 40Bqm-3 (UNSCEAR). The values of AEDE obtained in various borehole soil samples were less than the ICRP world average. Therefore, the soil samples in each of the borehole may not pose any health threat to the residents.

Assessment of Extent of Radiological Exposures in Subsurface Dumpsite Sediments around the Residential Area of Oru-Ijebu South-West Nigeria

Assessment of naturally occurring radionuclides was carried out from 20 sampling points in a dumpsite systematically collected from varying subsurface depth intervals of 0-0.2m, 0.2-0.4m, 0.4-0.6m, 0.6-0.8m and 0.8m-1.0m, while the control samples were taken from two sampling points located 200m away from the dumpsite. The samples were consequently analyzed in the laboratory for natural radioactive emission where each activity concentration measurements of the radionuclides were determined; the natural radionuclides identified were 226Ra, 238U, 232Th, 40K utilizing gamma ray spectrometry with NaI (IT) detector. The mean activity concentrations recorded in Bqkg-1 for 226Ra, 238U, 232Th and 40K in the subsurface soil samples were respectively 2.53±0.60, 31.50±2.01, 27.20±1.63 and 340.39±19.48 in depth 0m−0.2m; 1.96±0.37, 28.2455±2.50, 23.84±3.07 and 320.59±24.07 respectively in depth 0.2m-0.4m; 1.24±0.41, 24.197±3.66, 19.86±2.46 and 290.71±28.99 respectively in depth 0.4m−0.6m; 0.80±0.34 Bqkg-1, 20.10±4.133, 16.10±1.54, and 259.04±34.22 in depth 0.6m−0.8m and 0.68±0.25, 18.509±2.08, 14.50±0.91 and 247±30.13 for 0.8-1.0m. The levels of radioactivity were then used to assess public dose rates and radioactive contamination thereby predicting changes in environmental radioactivity caused by poor waste management, industrial activities, and other human activities. In all the investigated sampling point 40K exhibited the highest activity concentration in 0-0.2m depth with the value of 383.45±19.4883 while Pr exhibited the lowest activity concentration with the value of 0.08±0.4252 in depth 0.8-1.0m. The mean activity concentration of 238U, 232Th and 40K, in the soil samples at the dumpsite were 20.80, 20.3 and 291.54 Bqkg-1respectively for 0-0.2m depth. These results were lower than the world permissible standard stated by UNSCEAR. It was generally observed that the activity concentrations reduced with 0-0.2m having the highest concentration values for both the dumpsite and the control sites, while the mean activity concentrations of 238U, 232Th and40K for the control sites were found to be 31.5045±2.0123, 13.145±1.4637 and 183.415±21.4465 respectively for 0-0.2m depth.

Assessment of Radiation Dose Associated with Background Radionuclides in Quarry Soil at Dawakin-Kudu LGA Kano, Nigeria

Naturally occurring radioactive materials (NORMs) are present in different concentrations in the environment as well as quarry depending on the geological formation of the soil. The assessment of any release of radioactivity into the environment is crucial for safeguarding public health, particularly when this radioactivity has the potential to enter the food chain. The quarry located in Dawakin-Kudu Kano has the potential to exhibit elevated levels of natural radioactivity due to intense mining operations. This study presents the assessment of activity concentration in quarry soil at Dawakin-Kudu with a focus on the transfer mechanism from soil to plant. Soil samples were gathered from a quarry site and farmlands situated around the quarry at Dawakin-kudu, plant samples were also collected from the same farmlands and were all analyzed for natural radioactivity, specifically for 226Ra,232Th, and 40K. The gamma-ray spectrometry method, coupled with the Sodium thallium Iodide NaI (Tl) detector was used to measure the activity concentrations of 226Ra,232Th, and 40K. Activity concentrations of natural radioactivity in soil were generally higher than those recorded in plants. The mean activity concentration of the radionuclides in soil ranges from Highest-to-Lowest values as follows 226Ra: 65.24±1.92 Bqkg-1 – 42.41±1.73 Bqkg-1, 232Th: 182.71±1.44 Bqkg-1 – 114.61±1.25 Bqkg-1, 40K: 597.51±3.81 Bqkg-1 – 321.93±3.55 Bqkg-1. The radiological hazard indices were all determined to assess the radiation hazard of the quarry soil. The radionuclides transfer factor showed a higher value for 40K in the order 40K&gt;232Th &gt;226Ra, this implies high bioconcentration of 40K in plants. The findings suggest that consuming plants grown around the quarry location over an extended period could pose substantial health threats to the public. Consequently, the study area may not be safe for residents in the long run, emphasizing the necessity for continuous monitoring of radioactivity concentrations to mitigate the environmental health implications of accumulated...

Field Testing of Gamma-Spectroscopy Method for Soil Water Content Estimation in an Agricultural Field.

Gamma-ray spectroscopy (GRS) enables continuous estimation of soil water content (SWC) at the subfield scale with a noninvasive sensor. Hydrological applications, including hyper-resolution land surface models and precision agricultural decision making, could benefit greatly from such SWC information, but a gap exists between established theory and accurate estimation of SWC from GRS in the field. In response, we conducted a robust three-year field validation study at a well-instrumented agricultural site in Nebraska, United States. The study involved 27 gravimetric water content sampling campaigns in maize and soybean and 40K specific activity (Bq kg-1) measurements from a stationary GRS sensor. Our analysis showed that the current method for biomass water content correction is appropriate for our maize and soybean field but that the ratio of soil mass attenuation to water mass attenuation used in the theoretical equation must be adjusted to satisfactorily describe the field data. We propose a calibration equation with two free parameters: the theoretical 40K intensity in dry soil and a, which creates an "effective" mass attenuation ratio. Based on statistical analyses of our data set, we recommend calibrating the GRS sensor for SWC estimation using 10 profiles within the footprint and 5 calibration sampling campaigns to achieve a cross-validation root mean square error below 0.035 g g-1.

STUDIES TO ESTABLISH THE SCALING FACTOR METHODOLOGY FOR LIQUID RADIOACTIVE WASTE GENERATED BY TRIGA REACTOR

During TRIGA reactor operation significant amounts of liquid radioactive waste are generated requiring appropriate management to ensure their safe disposal. Radiological characterization is an important activity needed to accomplish the waste acceptance criteria for different management steps including disposal. The purpose of this paper is to assess the activity concentrations of the (_1^3)H , (_38^90)Sr, (_28^63)Ni (difficult-to-measure), and gamma emitters (easy-to-measure) radionuclides in liquid radioactive waste generated by the TRIGA reactor operation and to establish a correlation among them to determine the scaling factors for this waste category. The radiological protocols applied for (_28^63)Ni and (_38^90)Sr, separation and purification involve extraction chromatography using selective resins, while for (_1^3)H separation the distillation technique was applied. The assessment of gamma emitters was carried out using gamma-ray spectrometry and the detection of (_1^3)H , (_38^90)Sr, and (_28^63)Ni was performed by liquid scintillation counting. The chemical yield of each experiment was determined by measuring the carrier added in each test by inductively coupled plasma optical emission spectrometry. The activity concentrations of (_38^90)Sr, and (_28^63)Ni obtained were correlated with the activity concentration of (_27^60)Co for establishing the scaling factor for the liquid radioactive waste stream. There were obtained good correlations but more experimental data are needed to determine the relevant scaling factors for these difficult-to-measure radionuclides. The scaling factors, once established, will improve and optimize the radiological characterization methodology applied for liquid radioactive waste as an easy and rapid method for assessment of concentration activities of difficult-to-measure radionuclides. Until now, no scaling factors data were reported for this liquid radioactive waste generated by TRIGA reactor operated by Institute for Nuclear Research Pitesti. The results obtained in this work represent preliminary data for establishing correlations between difficult-to-measure and easy-to-measure radionuclides and will be used for developing a scaling factor methodology. This will further be used to determine the inventory of difficult-to-measure radionuclides in different waste streams generated by TRIGA operation and decommissioning (foreseen after 2035).

Evaluation of the Central Copper Contact Pin Effect in High-Energy Region in Gamma-ray Spectrometry

The detector must be modeled in the most accurate way when Monte Carlo simulation method is used for efficiency calculation in gamma-ray spectrometric studies. This study aims to investigate the effect of the copper contact pin inside the detector on the efficiency of the HPGe detector for high gamma-ray energies. Simulated efficiencies were determined for 6 different energies in the energy range of 1460.8 keV up to 2614.5 keV in point and cylindrical source geometry. According to the modeling using PHITS Monte Carlo simulation code, the presence of copper contact pin at high gamma-ray energies caused a decrease of up to 6% in detector efficiency. It was emphasized that this ignored parameter should be included in the modeling like all other geometric parameters used in detector modeling, by showing the effect on the efficiency.