Romul Mircea Margineanu

Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering | IFIN HH · Life and Environmental Sciences

To estimate the radiation hazard due to the natural terrestrial radioactivity, 598 samples of soil covering the entire Romanian territory were collected and analyzed for the distribution of natural radionuclides ⁴⁰K, ²²⁸Ac, and ²²⁶Ra. The ultra-low background Slanic-Prahova underground laboratory was used to determine the gamma-ray-specific activit...

To estimate the contribution of Chernobyl ¹³⁷Cs contamination, in 1993 and especially 2016, its total inventory was determined by gamma-ray high-resolution spectroscopy in 62 and respectively 747 soil samples covering the entire Romanian territory. This permitted to estimate the ¹³⁷Cs inventory as varying between 0.4 and 187 as well as between 0.2...

To estimate the contribution of Chernobyl ¹³⁷ Cs contamination, in 1993 and especially 2016, its total inventory was determinate by gamma-ray high resolution spectroscopy in 62 and respectively 747 soil samples covering entire Romanian territory. This permitted to estimate the 1993 and 2016 total ¹³⁷ Cs inventory to 43 ± 2 TBq and respectively to 1...

To estimate the contribution of Chernobyl ¹³⁷ Cs contamination, in 1993 and especially 2016, its total inventory was determined by gamma-ray high-resolution spectroscopy in 62 and respectively 747 soil samples covering the entire Romanian territory. This permitted us to estimate the 1993 and 2016 total ¹³⁷ Cs inventory to 43 ± 2 TBq and respectivel...

Determination of tritium along Danube River Banks, in shallow waters, from Baziaş to Sulina, led to an average value of 29 TU and to a slight increasing tendency. Upstream/downstream “signatures” of Kozloduy NPP and Cernavoda NPP, and lower values on the left bank than on right bank in Romania, between Ostrov and Tulcea were highlighted. For Black...

We report the results of the analyses of the cosmic ray data collected with a 4 tonne (3×1×1 m ³ ) active mass (volume) Liquid Argon Time-Projection Chamber (TPC) operated in a dual-phase mode. We present a detailed study of the TPC's response, its main detector parameters and performance. The results are important for the understanding and further...

The 3×1×1 m3 demonstrator is a dual phase liquid argon time projection chamber that has recorded cosmic rays events in 2017 at CERN. The light signal in these detectors is crucial to provide precise timing capabilities. The performance of the photon detection system, composed of five PMTs, are discussed. The collected scintillation and electrolumin...

The $3 \times 1 \times 1$ m$^3$ demonstrator is a dual phase liquid argon time projection chamber that has recorded cosmic rays events in 2017 at CERN. The light signal in these detectors is crucial to provide precise timing capabilities. The performances of the photon detection system, composed of five PMTs, are discussed. The collected scintillat...

We use an underground counting lab with an extremely low background to perform an activity measurement for the C12+13C system with energies down to Ec.m.=2.323 MeV, at which the 12C(13C,p)24Na cross section is found to be 0.22(7) nb. The C12+13C fusion cross section is derived with a statistical model calibrated using experimental data. Our new res...

We present a facility for direct measurements at low and very low energies typical for nuclear astrophysics. The facility consists of a small and robust tandem accelerator where irradiations are made and an ultra-low background laboratory located in a salt mine where very low radio-activities can be measured. Both belong to “Horia Hulubei” National...

The probabilities of locating peaks with a high relative peak-area uncertainty were determined empirically with nine types of peak-location software used in laboratories engaged in gamma-ray spectrometry measurements. It was found that it is not possible to locate peaks with a probability of 0.95, when they have a relative peak-area uncertainty in...

We use an underground counting lab with an extremely low background to perform an activity measurement for the $^{12}$C+$^{13}$C system with energies down to $E\rm_{c.m.}$=2.323 MeV, at which the $^{12}$C($^{13}$C,$p$)$^{24}$Na cross section is found to be 0.22(7) nb. The $^{12}$C+$^{13}$C fusion cross section is derived with a statistical model ca...

We present a facility for direct measurements at low and very low energies typical for nuclear astrophysics (NA). The facility consists of a small and robust tandem accelerator where irradiations are made, and an ultra-low background laboratory located in a salt mine where very low radio-activities can be measured. Both belong to Horia Hulubei Nati...

Using our IFIN-HH facilities: the 3 MV TandetronTM accelerator and the ultra-low background laboratory we were able to study the ⁴He+⁶⁴Zn reaction at energies under Coulomb barrier. With these facilities, cross sections of the order of 30 nb were obtained. The thick target yields were determined through measurements of γ-ray yield followed by the d...

The noble gas Radon is a chemical element that has no stable isotopes. Radon isotopes result from the disintegration of ²³⁸U, ²³⁵U and ²³²Th. The half-life of ²²²Rn is 3.8235 days, for ²²⁰Rn is 55.6 s and for ²¹⁹Rn is 3.96 s. Radon is the second cause of lung cancer for the population after smoking, [1, 2]. Medical studies have provided clear evide...

Cosmic-ray muons have been studied at IFIN-HH for more than 20 years. Starting as fundamental physics research, the muon flux measurements bring new directions of study regarding muography. Two new directions have been recently developed: underground muon scanning of old mining sites in order to detect the possible presence of unknown cavities and...

A 10 kilo-tonne dual-phase liquid argon TPC is one of the detector options considered for the Deep Underground Neutrino Experiment (DUNE). The detector technology relies on amplification of the ionisation charge in ultra-pure argon vapour and offers several advantages compared to the traditional single-phase liquid argon TPCs. A 4.2 tonne dual-phas...

Marine living resources are a recognized food basis. The exploitation of species with economic value has increased in intensity, along with the sharp global food demand. The Black Sea, as a semi-enclosed sea, has a limited potential in this respect. The stocks have decreased recently and, consequently, restricted limits of fishing are needed in all...

A 10 kilo-tonne dual-phase liquid argon TPC is one of the detector options considered for the Deep Underground Neutrino Experiment (DUNE). The detector technology relies on amplification of the ionisation charge in ultra-pure argon vapour and others several advantages compared to the traditional single-phase liquid argon TPCs. A 4.2 tonne dual-phas...

Tourist activities on the seaside, but not exclusively, are dependent of the quality of the environmental components from the coastal zone. The water and the substrate are some of the main components. Their importance is supported, on the other hand, by their background role in the marine ecosystem. The surveillance of the radioactive indicator for...

Heavy-ion fusion reactions between light nuclei such as carbon and oxygen isotopes have been studied because of their significance for a wide variety of stellar burning scenarios [1]. One important stellar reaction is ¹²C+¹²C, but it is difficult to measure in the Gamow window because of very low cross sections and several resonances occurring [2]....

A method is presented for calculating the expected number of counts in peaks that have a large relative peak-area uncertainty and appear in measured gamma-ray spectra. The method was applied to calculations of the correction factors for peaks occurring in the spectra of radon daughters. It was shown that the factors used for correcting the calculat...

Chituc is a sand bank which separates the waters of Lake Sinoe and the Black Sea. It was established as protected area of national interest [1]. Sand samples were taken on the surface of the sand bank in order to assess the radioactivity between Corbu village (south) and channel Periboina (north). Samples were measured by high-resolution gamma spec...

Heavy-ion fusion reactions between light nuclei such as carbon and oxygen isotopes have been studied because of their significance for a wide variety of stellar burning scenarios. One important stellar reaction is 12C+12C, but it is difficult to measure it in the Gamow window because of very low cross sections and several resonances occurring. Hint...

In the recent work at Notre Dame, correlations between three carbon isotope fusion systems have been studied and it is found that the fusion cross sections of 12C+13Cand 13C+13C provide an upper limit on the fusion cross section of the astrophysically important 12C+12C reaction.The aim of this work is to continue such research by measuring the fusi...

The present work is related to the efforts of knowledge of the distribution of the different radioactive isotopes in the environment and their possible influences of the flora and fauna in different regions, as well as on the quality of the different aliments. For this study the rivers that assure the water for artificial reservoir created in villa...

Two methods of monitoring soil redistribution along agroterraces were explored in Tarina basin of the Moldavian Plateau: The classical method of annual or periodic field measurements and the 137C technique. Results obtained by both methods indicate that the aggradation rate of the agroterrace edge averages 5.0-6.0 cm/yr, but the 137C technique is m...

The black sand of the Chituc marine sand bank, northern of the city of Navodari (Romania), presents anomalous high radioactivity. Field measurements recorded in some places dose rate up to 200 nSv/h, significantly overpassing the average value of 44 ± 20 nSv/h along the entire Southern sector of Romanian Black Sea shore. Gamma ray spectrometry per...

The proposed Long Baseline Neutrino Observatory (LBNO) initially consists of $\sim 20$ kton liquid double phase TPC complemented by a magnetised iron calorimeter, to be installed at the Pyh\"asalmi mine, at a distance of 2300 km from CERN. The conventional neutrino beam is produced by 400 GeV protons accelerated at the SPS accelerator delivering 70...

The black sand of the Chituc marine sandbank, northern of the city of Navodari (Romania), presents anomalous high radioactivity. Field measurements recorded in some places dose rate up to 200 nSv/h, significantly overpassing the average value of 44 ± 20 nSv/h along the entire Southern sector of Romanian Black Sea shore. Gamma ray spectrometry perf...

One of the main goals of the Long Baseline Neutrino Observatory (LBNO) is to study the $L/E$ behaviour (spectral information) of the electron neutrino and antineutrino appearance probabilities, in order to determine the unknown CP-violation phase $\delta_{CP}$ and discover CP-violation in the leptonic sector. The result is based on the measurement...

In June 2012, an Expression of Interest for a long-baseline experiment (LBNO) has been submitted to the CERN SPSC. LBNO considers three types of neutrino detector technologies: a double-phase liquid argon (LAr) TPC and a magnetised iron detector as far detectors. For the near detector, a high-pressure gas TPC embedded in a calorimeter and a magnet...

Since 2006 a modern laboratory has been developed by IFIN-HH in the underground of Slanic Prahova salt ore. This work presents a short review of previous scientific activities performed in the underground laboratory, in parallel with some plans for the future. A mobile detector for cosmic muon flux measurements has been set up at IFIN-HH, Romania....

The black sand of the Chituc marine sandbank situated northern of the city of Navodari (Romania), displayed anomalous high ambient dose rates. Field measurements performed during 2013 Summer campaign recorded in some places dose rate up to 200 nSv/h, significantly overpassing the average value of 44 ± 20 nSv/h recorded along the entire Southern sec...

We have performed experiments to check the limits of sensitivity of the activation method using the new 3 MV Tandetron accelerator and the low and ultra-low background laboratories of the “Horia Hulubei” National Institute of Physics and Nuclear Engineering (IFIN-HH). We have used the 12C+13C reaction at beam energies Elab= 6, 7 and 8 MeV. The know...

TL measurements, independently performed on 114 rock salt samples collected at a depth of between 130 and 210 m from the Cantacuzino mine located in the Slanic-Prahova halite deposits and on Fimel TM GR200A TL dosimeters, showed a monotonous decrease of the dose rate with depth in good correlation with the muon flux. The latter was calculated on th...

The next generation neutrino observatory proposed by the LBNO collaboration will address fundamental questions in particle and astroparticle physics. The experiment consists of a far detector, in its first stage a 20 kt LAr double phase TPC and a magnetised iron calorimeter, situated at 2300 km from CERN and a near detector based on a highpressure...

The Black Sea tritium level was investigated in 33 places southward the Danube Delta covering about 360 km of the Black Sea Western Shore. Both surface (10 cm depth) and bottom (up to 20 m depth) water samples were collected. In the close vicinity of Danube Delta, the tritium activity concentration in the surface water was around 28 TU, which is al...

We describe the measurement of the activity concentration of natural radionuclides in a slag material intended to be spiked with a standard solution of 226Ra. The final aim was to produce standard sources within a EURAMET-European Metrology Research Program research project (MetroMetal). High resolution gamma-ray spectrometry was performed in five...

The ambient dose rate distribution, measured along the Southern sector of Romanian Black Sea shore, between Vama Veche in South and Chituc sandbank in North gave, with some notable exception, values between 34 and 54 nSv/h, lower than the 90 nSv/h, the average value for Romania. The experimental dose rates increase northward, reaching a maximum in...

A detailed analysis is presented of background radiation spectra for a high-resolution gamma-ray spectrometer used to measure environmental radioactivity, for various shielding configurations. The main goal is to improve the detection limits of low-level activity measurements by reducing the background as much as possible. Passive shielding configu...

Precise measurements of the muon flux are important for different practical applications, both in environmental studies and for the estimation of the water equivalent depths of underground sites. A mobile detector for cosmic muon flux measurements has been set up at IFIN-HH, Romania. The device is used to measure the muon flux on different location...

A typical example of gamma spectrometry application using 137Cs technique is related to the assessment of sedimentation rates in both the river floodplains and the reservoirs. The presence of 137Cs in soil and sediments is mainly associated to the Chernobyl accident. This paper deals with the four sites within the Moldavian Plateau, namely: three r...

This paper presents one part of the activities deployed by the Laboratory for Environment and Personnel Dosimetry (LDPM) of IFIN-HH, namely the radiological monitoring of the environment within the Institute's area and its surrounding influence zone, according to the program approved by the National Regulatory Body for Nuclear Activities, CNCAN. Th...

There are fundamental questions in particle and astroparticle physics that are still open. New experimental facilities as sources of particles and detection systems are needed to solve them. An incompletely understood sector of particle physics is the low energy neutrino interactions. The scope of this contribution is to investigate the possibility...

There are fundamental questions in particle and astroparticle physics that are still open. New experimental facilities as sources of particles and detection systems are needed to solve them. An incompletely understood sector of particle physics is the low energy neutrino interactions. The scope of this contribution is to investigate the possibility...

The main objective of the project is to establish the level of radiation background and its sources in the Black Sea coastal environment. Marine samples will be collected in the Black Sea Coast area. The content of different radionuclides will be analyzed and the results will be used in a GIS application. The gamma emitting radionuclides will be me...

With the advent of intense accelerator-based sources of neutrinos and the demand of neutrino oscillation experiments to more precisely determine signal and background rates in their detectors has precipitated a resurged interest for neutrino interactions in the few-GeV energy range. Such measurements have not been updated for decades, having first...

Measurements of 131I (T1/2 = 8.04 days) activities have been performed in the IFIN HH (Horia Hulubei National Institute of Physics and Nuclear Engineering) underground laboratory situated in Unirea salt mine, Slanic-Prahova, Romania. The rainwater samples were collected starting on 27 March from Brasov and Slanic-Prahova. Also sheep and goat milk s...

Measurements of the underground atmospheric muon flux are important in order to determine accurately the overburden in mwe (meter water equivalent) of an un-derground laboratory for appreciating which kind of exper-iments are feasible for that location. Slanic-Prohava is one of the 7 possible locations for the European large un-derground experiment...

Muons comprise an important contribution of the natural radiation dose in air (approx. 30 nSv/h of a total dose rate of 65-130 nSv/h), as well as in underground sites even when the flux and relative contribution are significantly reduced. The flux of the muons observed in underground can be used as an estimator for the depth in mwe (meter water equ...

Measurements of I-131 (T1/2 = 8.04 days) have been performed in IFIN-HH's underground laboratory situated in Unirea salt mine from Slanic-Prahova, Romania. The rain water samples were collected in March 27th in Brasov and in March 27th, 29th and April 2nd in Slanic. Also sheep milk was collected in Slanic area and subsequently measured. The samples...

This paper presents the first deep profile of the integrated dose of the salt mine "Unirea" from Slanic-Romania, obtained with commercially TL detectors. The TL characteristics of natural salt rock of this mine are also put in evidence. These results contain useful physical information for a characterization of the radioactivity of the mine galleri...

A new mobile detector was developed in IFIN‐HH, Romania, for measuring muon flux at surface and in underground. The measurements have been performed in the salt mines of Slanic Prahova, Romania. The muon flux was determined for 2 different galleries of the Slanic mine at different depths. In order to test the stability of the method, also measureme...

The design of a large detection infrastructure for measurements of very rare events like proton decay, or neutrino astrophysics, is in preparation and has a strong support from EU by the FP7 project LAGUNA (Design of a pan-European Infrastructure for Large Apparatus studying Grand Unification and Neutrino Astrophysics). The project has the main goal...

The feasibility of a next generation neutrino observatory in Europe is being considered within the LAGUNA design study. To accommodate giant neu- trino detectors and shield them from cosmic rays, a new very large under- ground infrastructure is required. Seven potential candidate sites in differ- ent parts of Europe and at several distances from CE...

The muons represent the EAS penetrating component and carry information about the mass and the energy of the primary cosmic particle, under the influence of the Earth magnetic field. The study of the high energy muon flux brings new informations regarding the muon multiplicities and the hadronic interaction models. The high energy muons represent,...

The feasibility of a next generation neutrino observatory in Europe is being considered within the LAGUNA design study. To accommodate giant neutrino detectors and shield them from cosmic rays, a new very large underground infrastructure is required. Seven potential candidate sites in different parts of Europe and at several distances from CERN are...

Aerosol samples collected on filter media were analyzed using HPGe detectors employing varying background-reduction techniques in order to experimentally evaluate the opportunity to apply ultra-low background measurement methods to samples collected, for instance, by the Comprehensive Test Ban Treaty International Monitoring System (IMS). In this w...

A next generation European deep underground neutrino observatory is considered within the LAGUNA design study. Three detector options are presently considered: GLACIER liquid argon Time Projection Chamber; LENA liquid scintillator and MEMPHYS water Cherenkov. It will provide both: the high statistics measurement of neutrinos from variety of sources...

The distribution of the external dose rate within the former Unirea salt mine, host of the Low-Level Background Laboratory was determined and compared with calculated values based on the experimentally determined content of natural radioactive elements in the mine walls. The average external dose rate was found to be 1.3+/-0.3 nSv h(-1), close to c...

Phosphogypsum is a by-product of the phosphoric acid based fertilizer industry; it can be used in agriculture and to make building materials. Phosphogypsum is radioactive due to the presence of technically enhanced naturally occurring radionuclides (TENORM) and its environmental impact is a major concern of the public authorities. The Radionuclide...

Three highly sensitive analytical methods: epithermal neutron activation analysis (ENAA), radiometric assay and UV/Vis spectroscopy were used to investigate the elemental composition of both halite and mineral fractions (sediments) of salt collected from the Slanic-Prahova salt mine, near the location of Low Background Radiation Laboratory. For hal...

A low-background radiation laboratory was constructed and fully commissioned in 2006 in the former Unirea (Slanic-Prahova) salt mine at 208 m below surface (estimated to 560 m water equivalent). Preliminary measurements showed a global reduction of the absorbed dose due to natural factors of about 39 times compared to level on the surface, reaching...

Nowadays, nuclear astrophysics has to give high precision values for nuclear values which are part of stellar evolution models. The stable beam accelerators play an important role in the process of measuring the very low energy nuclear cross sections. The very low event reaction rate may be separated from the background only if it exceeds the detec...

Keywords:salt mine;ultralow radiation background;radon daughters;potassium 40

The acceleration of erosion processes, associated with land degradation represents, for a long term, a major problem for the sustainable agriculture. Beyond the protection, the reservoirs have also other functions like: drinking water sources for neighbouring towns and villages; irrigation water Sources for agricultural land; fishing; recreational...

The molecular symmetry of Dibenzo-12(to 24)-crown-4(to 8) ethers was analyzed using HyperChem 5.02. Computational Chemistry Model Building Program. The results are in agreement with those obtained with earlier experimental data and molecular models built with Fisher-Hirsch-Welder-Taylor atomic models in the crown ethers series, and will be a helpfu...

Radioactive concentrations of several artificial and natural radionuclides were determined in water and sediment samples collected from various locations in the NW Black Sea in December 1999. For water samples, 90Sr and 137Cs activity concentrations were of approximately 11 mBq/l and 26.3-41.2 mBq/l, respectively. The concentration of tritium range...

Two methods of monitoring soil redistribution along agroterraces were explored in Tarina basin of the Moldavian Plateau: the classical method of annual or periodic field measurements and the 137C technique. Results obtained by both methods indicate that the aggradation rate of the agroterrace edge averages 5.0-6.0 cm/yr, but the 137C technique is m...

Reservoir sedimentation has been recognized as an important environmental threat in the Moldavian Plateau of Eastern Romania. Measurements of the 137Cs content of reservoir and, sometimes, floodplain sediments have been used to estimate the rate of sedimentation over the past 13-36 years . The estimated mean sediment accumulation rates in the reser...

In Romaia, CANDU Nuclear Power Plant with five reactors of 600 MWe is under construction at Cernavoda town and in 1996 the first reactor was put in operation. The background level of tritium concentration was determined in preoperational stage. The mean values determined are: (7.4±5.5) Bq/l in air humidity, 3.1±1.0) Bq/l in water, (3.5±0.7) Bq/l in...

The dynamics of137Cs soil-to-plant transfer has been studied for 21 vegetal species in an agricultural area not far from Bucharest, during a two year experiment started one year after the Chemobyl nuclear accident. The results, generally fitting in the value ranges found in literature, are discussed in the strict sense of the definition for soil-to...

This paper presents the results of radioactivity studies of environmental factors such as surface water, sediment, aquatic vegetation and soil. The concentrations of137Cs,90Sr,3H, U, Ca, and Mg in water samples were determined by radiochemical and chemical methods. Gamma-spectrometric analyses were performed for all the samples. The analysis showed...

This work shows the variation of90Sr and137Cs in atmospheric fallout in the Bucharest-Mgurele area during 1986–1987. The amount of90Sr in the fallout was estimated to be about 900 Bq.m–2 in 1986 and about 9.2 Bq.m–2 in 1987. The amount of137Cs was estimated to be 13300 and 615 Bq.m–2 in 1986 and 1987, respectively.