In the present study, outdoor gamma dose rates have been measured by using a NaI(Tl) scintillation detector in 20 measurement points in the Tavsanly district center of Kutahya province in Turkiye. Annual effective dose equivalents and lifetime cancer risks have been calculated from the obtained results as (106.64 ?6.20) ?Sv and (3.73 ?0.2) ?10-4, respectively. The results have been compared with those of other studies for Turkiye and the world literature
A narrow near-threshold proton-emitting resonance (Ex = 11.4 MeV, J$^π$ = 1/2$^{+}$ and $Γ_{p}$ = 4.4 keV) was directly observed in $^{11}$B via proton resonance scattering. This resonance was previously inferred in the $β$-delayed proton emission of the neutron halo nucleus $^{11}$Be. The good agreement between both experimental results serves as a ground to confirm the existence of such exotic decay and the particular behavior of weakly bound nuclei coupled to the continuum. $R$-matrix analysis shows a sizable partial decay width for both, proton and $α$ emission channels.
The purpose of this research was to determine how dose area product, effective dose, absorbed doses to specific organs, and image quality changed according to different automatic exposure control positions in pelvis imaging. The research was carried out in two parts. The study was conducted on an anthropomorphic phantom and 200 patients referred to pelvic imaging. We measured the dose area product, field size, height, and mass. Then we calculated the effective dose and absorbed dose for individual organs accordingly. Lateral ionizing cells were first positioned in line with the iliac crests (head towards position) and subsequently, with the femoral neck (head away position). All the images were independently evaluated by three radiologists using ViewDEX and objective image analysis was performed measuring contrast-to-noise ratio and signal-to-noise ratio. We found no significant differences in the Siemens Luminos unit in any of the inspected parameters. However, there was a significant difference in dose area product (37.3 %), effective dose (35.7 %) and average absorbed dose to selected individual organs (36.7 %) when the head away position of the patient was used and the image quality increased. Based on these results, we can propose that the optimal position of the patient regarding the ionizing cells is the head away position.
Feliks Finkel, Igors Krainukovs, Vasily Litvinsky
et al.
The article presents the results of the development of the scintillation gamma spectrometers, based on NaI(Tl), LaBr3 or SrI2(Eu) scintillators, intended for aerosol monitoring over a wide temperature range. The stabilization of the characteristics is provided by applying various stabilization methods of the spectrometric chain. The estimation of the impact of those methods on the stability of the characteristics of the developed radiation spectrometer is provided.
This study presents the results of 226Ra content in 104 Bulgarian mineral waters as well as the investigated correlations between the physicochemical parameters, geological structure, and specific activity of 226Ra. The results show that the 226Ra activities range from <30 mBqL-1 to 4900 mBqL-1 with a mean value of 156 mBqL-1. The highest concentrations of 226Ra were measured in mineral waters originating from the carbonate strata, as the dominant geological structure. Thus it is well connected with the estimated moderate positive correlation between Ca2+, Mg2+, and Ra2+ cations in the water. The estimated annual dose shows large dispersion of values ranging from 6 ?Sv to 1000 ?Sv with a mean value of 32 ? 9 ?Sv. The results demonstrate the need for further investigation of every mineral water, but greater attention should be given to the mineral waters with low pH and high content of Ca2+ and Mg2+.
Proton inelastic scattering off a neutron halo nucleus, 11Li, has been studied in inverse kinematics at the IRIS facility at TRIUMF. The aim was to establish a soft dipole resonance and to obtain its dipole strength. Using a high quality 66 MeV 11Li beam, a strongly populated excited state in 11Li was observed at Ex=0.80 +/- 0.02 MeV with a width of 1.15 +/- 0.06 MeV. A DWBA (distorted-wave Born approximation) analysis of the measured differential cross section with isoscalar macroscopic form factors leads to conclude that this observed state is excited in an electric dipole (E1) transition. Under the assumption of isoscalar E1 transition, the strength is evaluated to be extremely large amounting to 600 to 2000 Weisskopf units, exhausting 4% to 14% of the isoscalar E1 energy-weighted sum rule (EWSR) value. The large observed strength originates from the halo and is consistent with the simple di-neutron model of 11Li halo.
Longevity of sensors and portable devices is severely limited by temperature, chemical instability, and electrolyte leakage issues associated with conventional electrochemical batteries. Betavoltaics, which operate similar to photo voltaics, can operate in a wide temperature range safely without permanent degradation. Though not a new concept, which began in the 1950's and peaked in the mid 1970's, research has been minimal and sporadic until recent advancements in ultra-low power electronics and materialization of low power applications. The technology is rapidly maturing, generating research, and development in increasing the beta emitting source and semiconductor efficiencies. This study presents an update on betavoltaic technology, results from temperature evaluation on commercially available General Licensed betavoltaic cells, development of a hybrid system for latent and burst power, modeling and simulation techniques and results, and current and proposed research and development. Betavoltaic performance was successfully demonstrated for a wide temperature range (-30?C to 70?C). Short circuit current and open circuit voltage were used to compare electrical performance. Results indicate that the open-circuit voltage and maximum power decreased as temperature increased due to increases in the semiconductor's intrinsic carrier concentration.
We report the first direct measurement of the $^{14}\text{O}$ superallowed Fermi $β$-decay $Q_{EC}$-value, the last of the so-called "traditional nine" superallowed Fermi $β$-decays to be measured with Penning trap mass spectrometry. $^{14}$O, along with the other low-$Z$ superallowed $β$-emitter, $^{10}$C, is crucial for setting limits on the existence of possible scalar currents. The new ground state $Q_{EC}$ value, 5144.364(25) keV, when combined with the energy of the $0^+$ daughter state, $E_x(0^+)=2312.798(11)$~keV [Nucl. Phys. A {\bf{523}}, 1 (1991)], provides a new determination of the superallowed $β$-decay $Q_{EC}$ value, $Q_{EC}(\text{sa}) = 2831.566(28)$ keV, with an order of magnitude improvement in precision, and a similar improvement to the calculated statistical rate function $f$. This is used to calculate an improved $\mathcal{F}t$-value of 3073.8(2.8) s.
Investigating partonic interactions is one of the primary goals of the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). RHIC is specially tailored for studying intrinsic partonic spin-momentum correlations due to its unique ability to collide polarized proton beams. Transverse single-spin asymmetries of order 10% have been measured in PHENIX at center of mass energies from 62.4 GeV to 200 GeV, similar to previous measurements. These results indicate that there exist partonic transverse momentum effects within the proton and/or within the process of hadronization. The MPC-EX, a new silicon-tungsten preshower detector at PHENIX, has taken data for the first time this year with the intent of shedding further light on the origins of these asymmetries. A review of the status of the detector and of future planned measurements will be presented. An overview of ongoing work by PHENIX aimed at measuring intrinsic partonic transverse momentum will be discussed.
Experimental form factors of the hydrogen and helium isotopes, extracted from an up-to-date global analysis of cross sections and polarization observables measured in elastic electron scattering from these systems, are compared to predictions obtained in three different theoretical approaches: the first is based on realistic interactions and currents, including relativistic corrections (labeled as the conventional approach); the second relies on a chiral effective field theory description of the strong and electromagnetic interactions in nuclei (labeled $χ$EFT); the third utilizes a fully relativistic treatment of nuclear dynamics as implemented in the covariant spectator theory (labeled CST). For momentum transfers below $Q \lesssim 5$ fm$^{-1}$ there is satisfactory agreement between experimental data and theoretical results in all three approaches. However, at $Q \gtrsim 5$ fm$^{-1}$, particularly in the case of the deuteron, a relativistic treatment of the dynamics, as is done in the CST, is necessary. The experimental data on the deuteron $A$ structure function extend to $Q \simeq 12$ fm$^{-1}$, and the close agreement between these data and the CST results suggests that, even in this extreme kinematical regime, there is no evidence for new effects coming from quark and gluon degrees of freedom at short distances.
Zdravko Vejnovic, Milos Pavlovic, Marina Kutin
et al.
A new method for fitting glow curves, described in a mixed order kinetics model, with Gauss-Lorentz function is shown. Theoretical expressions of the mixed order kinetics model are shown in a new way, so that the values of kinetic parameters can be obtained through the geometric parameters. When the model is described in this way it is possible to calculate precisely the kinetic parameters such as activation energy, pre-exponential factor and the factor a= n0/(h + n0). At the same time, obtained values of geometric parameters of the experimental curve, which is described with the Gauss-Lorentz function, can be used to estimate the kinetic model, in which thermoluminescence relaxation occurs. This gives a possibility of a new application of Gauss-Lorentz function to be used as a criterion for assessing model of relaxation, when it is not known in advance. The accuracy of fitting is studied, for the specific cases of computer simulated thermoluminescent curves with one peak.
Yu. E. Titarenko, K. V. Pavlov, V. I. Rogov
et al.
178m2-Hf is an extremely interesting isomeric state due to its potential energy capacity level. One possible way to obtain it is by irradiation of a nat-Ta sample with a high-current proton accelerator. Up to now, there was no information in the international experimental nuclear data base (EXFOR) for this reaction. Irradiations of nat-Ta samples performed for other purposes provide an opportunity to address this question. This paper presents the 172m2-Hf independent production cross-sections determined by gamma-ray spectrometry. The nat-Ta(p,x)172m2-Hf excitation function is studied in the 20-3500 MeV energy range. Comparisons with results by several nuclear models (ISABEL, Bertini, INCL4.5+ABLA07, PHITS, CASCADE07, and CEM03.02) used as event-generators in modern transport codes are also reported. However, since such models are generally not able to separately predict ground and isomeric states of reaction products, only 178-Hf independent and cumulative cross-section data are compared.
A non-invasive ultrasonographic assessment of systolic ejection peak in the middle cerebral artery is very efficient in detection of anomalies in alloimmunized pregnancies and is a diagnostic method of choice prior to cordocentesis. This is applied in combination with detection of titre of Rh(D) antibodies. In our study, two groups of patients were tested and results were compared. The first sample included 52 newborns in the period 1998-2007 (initial period of intrauteral intravascular transfusion, while the second one included 16 newborns from the period 1998-2008 (second period, when better prenatal control was achieved). Levels of titter of antibodies in salty environment, in both the control and the analyzed group, indicated moderate sensitization in a small group of patients. However, in albumin and in particular Coombs environment, the level of sensitization was significant in all patients (p>0.05; DF = 67). Our investigation suggests that with ultrasound as a method of choice and with prenatal screening it is possible to achieve better diagnosis and prognosis in the case of Rh(D) conditions of alloimmunized pregnancies.
We review the role of two-photon exchange (TPE) in electron-hadron scattering, focusing in particular on hadronic frameworks suitable for describing the low and moderate Q^2 region relevant to most experimental studies. We discuss the effects of TPE on the extraction of nucleon form factors and their role in the resolution of the proton electric to magnetic form factor ratio puzzle. The implications of TPE on various other observables, including neutron form factors, electroproduction of resonances and pions, and nuclear form factors, are summarized. Measurements seeking to directly identify TPE effects, such as through the angular dependence of polarization measurements, nonlinear epsilon contributions to the cross sections, and via e+ p to e- p cross section ratios, are also outlined. In the weak sector, we describe the role of TPE and gamma-Z interference in parity-violating electron scattering, and assess their impact on the extraction of the strange form factors of the nucleon and the weak charge of the proton.
Milos Vujisic, Koviljka Stankovic, Aleksandra Vasic
This paper compares the reliability of standard commercial Erasable Programmable Read Only Memory (EPROM) and Electrically Erasable Programmable Read Only Memory (E2PROM) components exposed to gamma rays. The results obtained for CMOS-based EPROM (NM27C010) and E2PROM (NM93CS46) components provide the evidence that EPROMs have greater radiation hardness than E2PROMs. Moreover, the changes in EPROMs are reversible, and after erasure and reprogramming all EPROM components restore their functionality. On the other hand, changes in E2PROMs are irreversible. The obtained results are analyzed and interpreted on the basis of gamma ray interaction with the CMOS structure.
Within a covariant parton cascade, we discuss the impact of both finite shear viscosity $η$ and freeze-out dynamics on the elliptic flow generated at RHIC. We find that the enhancement of $η/s$ in the cross-over region of the QGP phase transition cannot be neglected in order to extract the information from the QGP phase. We also point out that the elliptic flow $v_2(p_T)$ for a fluid at $η/s \sim 0.1-0.2$ is consistent with the one needed by quark number scaling drawing a nice consistency between the nearly perfect fluid property of QGP and the coalescence process.
alpha-d coincidence data were studied for the 6Li + 59Co reaction at E(lab) = 29.6 MeV. By using a kinematic analysis, it was possible to identify which process, leading to the same final state, has the major contribution for each of the selected angular regions. Contributions of the 6Li sequential and direct breakup to the incomplete fusion/transfer process were discussed by considering the lifetimes obtained by using a semiclassical approach, for both breakup components.
The safety assessment of research and power reactors is a continuous process covering their lifespan and requiring verified and validated codes. Power reactor codes all over the world are well established and qualified against real measuring data and qualified experimental facilities. These codes are usually sophisticated, require special skills and consume a lot of running time. On the other hand, most research reactor codes still require much more data for validation and qualification. It is, therefore, of benefit to any regulatory body to develop its own codes for the review and assessment of research reactors. The present paper introduces a simple, one-dimensional Fortran program called THDSN for steady-state thermal-hydraulic calculations of plate-type fuel research reactors. Besides calculating the fuel and coolant temperature distributions and pressure gradients in an average and hot channel, the program calculates the safety limits and margins against the critical phenomena encountered in research reactors, such as the onset of nucleate boiling, critical heat flux and flow instability. Well known thermal-hydraulic correlations for calculating the safety parameters and several formulas for the heat transfer coefficient have been used. The THDSN program was verified by comparing its results for 2 and 10 MW benchmark reactors with those published in IAEA publications and a good agreement was found. Also, the results of the program are compared with those published for other programs, such as the PARET and TERMIC.
Multiple collision theory of light ion ranges in an infinite medium has been used to calculate reflection coefficient from penetration profile in the energy region where the electronic stopping is dominating and proportional to the ion velocity. Ion-target atom collisions are determined by the inverse square scattering potential. The Gaussian approximation of a penetration profile as well as reflection coefficient are found in the form of analytic formulas. Corrections for multiple crossings of the surface have been applied. The results are compared with those from our previous calculations on the basis of DP0 solution of the transport equation and with the computer simulation data.
Here, we present a three-dimensional model of track growth in nuclear track detectors. The equation for the track wall in three dimensions and the equation of the contour line of the track opening have been derived for all types of tracks (i. e., tracks with sharp tips and tracks with rounded tips). The expression for the surface area of the track opening has also been found. The equations become the well-known expressions for minor and major axes for the special case of constant track etch rates. Computations of track parameters based on our model have been compared with the track growth models given by Somogyi and Szalay and the one given by Fews and Henshaw. Good agreements have been found among these three independent models.