JINR rapid communications

International Nuclear Information System (INIS)

1999-01-01

The present collection of rapid communications from JINR, Dubna, contains seven separate records on additional conditions on eigenvectors in solving inverse problem for two-dimensional Schroedinger equation, on an absolute calibration of deuteron beam polarization at LHE, determination of the vector component of the polarization of the JINR synchrophasotron deuteron beam, wavelet-analysis: criterion of reliable signal selection, on asymptotics in inclusive production of antinuclei and nuclear fragments, use of neutron activation analysis at the IBR-2 reactor for atmospheric monitoring and impulse method for temperature measurement of silicon detectors

Analyzing power of polarized protons interactions with carbon nuclei at 0.71-3.61 GeV

International Nuclear Information System (INIS)

Anoshina, E.V.; Bodyagin, V.A.; Vardanyan, I.N.; Gribushin, A.M.; Ershov, A.A.; Kruglov, N.A.; Sarycheva, L.I.

1997-01-01

For the first time at JINR synchrophasotron an experiment in the polarized proton beam was carried out. Beams of polarized protons with energy T p = 0.71-3.61 GeV, polarization P p ≅ 0.5 and intensity I p ≅ 10 6 particles/spell have been formed, their characteristics were investigated, and a possibility to use those beams as initial for physical and methodical investigations has been shown. The proton-carbon interaction analyzing power at the energies of 1.46 and 3.61 GeV has been measured for two values of the scattering angle. 22 refs., 3 figs

Determination of spatial and energy distributions of neutrons in experiments on transmutation of radioactive waste using relativistic protons

International Nuclear Information System (INIS)

Zhuk, I.V.; Lomonosova, E.M.; Boulyga, S.F.; Kievitskaia, A.I.; Rakhno, I.L.; Chigrinov, S.E.; Bradnova, V.; Krivopustov, M.I.; Kulakov, B.A.; Brandt, R.; Ochs, M.; Wan, J.-S.

1999-01-01

The experiments on transmutation of 129 I and 237 Np using uranium-lead targets surrounded by a paraffin moderator were performed at the Joint Institute for Nuclear Research (JINR, Russia). The targets were irradiated by 1.5 GeV and 7.4 GeV protons at the Synchrophasotron of JINR. In the frame of present work spatial and energy distributions of neutrons on the surface of the paraffin moderator were measured using SSNTD technique. It is shown that measured values of spectral indices do not depend on the energy of incident protons but depend on the target composition. The presence of the uranium insertion softens neutron spectra

Determination of spatial and energy distributions of neutrons in experiments on transmutation of radioactive waste using relativistic protons

Energy Technology Data Exchange (ETDEWEB)

Zhuk, I.V.; Lomonosova, E.M.; Boulyga, S.F.; Kievitskaia, A.I.; Rakhno, I.L.; Chigrinov, S.E.; Bradnova, V.; Krivopustov, M.I.; Kulakov, B.A.; Brandt, R.; Ochs, M.; Wan, J.-S

1999-06-01

The experiments on transmutation of {sup 129}I and {sup 237}Np using uranium-lead targets surrounded by a paraffin moderator were performed at the Joint Institute for Nuclear Research (JINR, Russia). The targets were irradiated by 1.5 GeV and 7.4 GeV protons at the Synchrophasotron of JINR. In the frame of present work spatial and energy distributions of neutrons on the surface of the paraffin moderator were measured using SSNTD technique. It is shown that measured values of spectral indices do not depend on the energy of incident protons but depend on the target composition. The presence of the uranium insertion softens neutron spectra.

Phenomenological pictures on the cumulative effect in nucleus-nucleus collisions at the incident kinetic energy of 3.65 A GeV

International Nuclear Information System (INIS)

Besliu, Calin; Jipa, Alexandru; Zaharia, Radu; Tugulea, Mircea; Iosif, Maria; Argintaru, Dan; Argintaru, Cristina

1996-01-01

In this work new experimental results on the cumulative production of the negative pions are reported. Eight central and peripheral (inelastic) collisions at 4.5 A GeV/c incident momentum are taken into account comparisons with experimental results on the cumulative effects obtained in n-p collisions at 4.53 GeV/c and O-Ne, O-Pb collisions at 4.5 A GeV/c are included in this work. A significant cumulative production of negative pions is observed. The non-equilibrium mechanisms can be considered for cumulative effect. The experiments have been performed at the Synchrophasotron from JINR Dubna in the frame of the SKM 200 Collaboration. (authors)

Measurements of the total cross-section difference ΔδL (np) at 1.39, 1.69, 1.89 and 1.99 GeV

International Nuclear Information System (INIS)

Sharov, V.I.; Anishchenko, N.G.; Antonenko, V.G.

2004-01-01

New accurate results of the neutron-proton spin-dependent total cross-section difference Δδ L (np) at the neutron beam kinetic energies of 1.39, 1.69, 1.89 and 1.99 GeV are presented. In general these data complete the measurements of energy dependence of Δδ L (np) over the Dubna Synchrophasotron energy region. The quasi-monochromatic neutron beam was produced by break-up of extracted polarized deuterons. The deuteron (and hence neutron) polarization direction was flipped every accelerator burst. The neutron vertical direction of polarization was rotated onto the neutron beam direction and longitudinally (L) polarized neutrons were transmitted through the large proton L-polarized target. The longitudinal target polarization direction was inverted after 1-2 days of measurements. Four different combinations of the beam and target parallel and antiparallel polarization directions, both oriented along the neutron beam momentum, were used at each energy. A fast decrease of - Δδ L (np) with increasing energy above 1.1 GeV and a structure in the energy dependence around 1.8 GeV, first observed from our previous data, seem to be well revealed. The new results are also compared with model predictions and with phase shift analysis fits. The Δδ L quantities for isosinglet state I = 0, deduced from the measured Δδ L (np) values and known Δδ L (pp) data, are also given. The results of the measurements of unpolarized total cross sections δ 0tot (np) at 1.3, 1.4 and 1.5 GeV and δ 0tot (nC) at 1.4 and 1.5 GeV are presented as well. These data were obtained using the same apparatus and high intensity unpolarized deuteron beams extracted either from the Synchrophasotron, or from the Nuclotron

Measurement of the np total cross section difference Δ σ L(np) at 1.39, 1.69, 1.89 and 1.99 GeV

Science.gov (United States)

Sharov, V. I.; Anischenko, N. G.; Antonenko, V. G.; Averichev, S. A.; Azhgirey, L. S.; Bartenev, V. D.; Bazhanov, N. A.; Belyaev, A. A.; Blinov, N. A.; Borisov, N. S.; Borzakov, S. B.; Borzunov, Yu T.; Bushuev, Yu P.; Chernenko, L. P.; Chernykh, E. V.; Chumakov, V. F.; Dolgii, S. A.; Fedorov, A. N.; Fimushkin, V. V.; Finger, M.; Finger, M.; Golovanov, L. B.; Gurevich, G. M.; Janata, A.; Kirillov, A. D.; Kolomiets, V. G.; Komogorov, E. V.; Kovalenko, A. D.; Kovalev, A. I.; Krasnov, V. A.; Krstonoshich, P.; Kuzmin, E. S.; Ladygin, V. P.; Lazarev, A. B.; Lehar, F.; de Lesquen, A.; Liburg, M. Yu; Livanov, A. N.; Lukhanin, A. A.; Maniakov, P. K.; Matafonov, V. N.; Matyushevsky, E. A.; Moroz, V. D.; Morozov, A. A.; Neganov, A. B.; Nikolaevsky, G. P.; Nomofilov, A. A.; Panteleev, Tz; Pilipenko, Yu K.; Pisarev, I. L.; Plis, Yu A.; Polunin, Yu P.; Prokofiev, A. N.; Prytkov, V. Yu; Rukoyatkin, P. A.; Schedrov, V. A.; Schevelev, O. N.; Shilov, S. N.; Shindin, R. A.; Slunečka, M.; Slunečková, V.; Starikov, A. Yu; Stoletov, G. D.; Strunov, L. N.; Svetov, A. L.; Usov, Yu A.; Vasiliev, T.; Volkov, V. I.; Vorobiev, E. I.; Yudin, I. P.; Zaitsev, I. V.; Zhdanov, A. A.; Zhmyrov, V. N.

2004-09-01

New accurate results of the neutron-proton spin-dependent total cross section difference Δσ_L(np) at the neutron beam kinetic energies 1.39, 1.69, 1.89 and 1.99 GeV are presented. Measurements were carried out in 2001 at the Synchrophasotron of the Veksler and Baldin Laboratory of High Energies of the Joint Institute for Nuclear Research. A quasi-monochromatic neutron beam was produced by break-up of extracted polarized deuterons. The deuteron (and hence neutron) polarization direction was flipped every accelerator burst. The vertical neutron polarization direction was rotated onto the neutron beam direction and longitudinally (L) polarized neutrons were transmitted through a large proton L-polarized target. The target polarization vector was inverted after 1-2 days of measurements. The data were recorded for four different combinations of the beam and target parallel and antiparallel polarization directions at each energy. A fast decrease of Δσ_L(np) with increasing energy above 1.1 GeV was confirmed. The structure in the Δσ_L(np) energy dependence around 1.8 GeV, first observed from our previous data, seems to be well pronounced. The new results are also compared with model predictions and with phase shift analysis fits. The Δσ_L quantities for isosinglet state I = 0, deduced from the measured Δσ_L(np) values and the known Δσ_L(pp) data, are also given. The results were completed by the measurements of unpolarized total cross sections σ_{0tot}(np) at 1.3, 1.4 and 1.5 GeV and σ_{0tot}(nC) at 1.4 and 1.5 GeV. These data were obtained using the same apparatus and high intensity unpolarized deuteron beams were extracted either from the Synchrophasotron, or from the Nuclotron.

Reduced widths of alpha -decay of near-magic even-even nuclei

CERN Document Server

Kar Yan, N

1972-01-01

Precision on-line investigations on the linear heavy-ion Berkeley accelerator, and on the CERN synchrophasotron were carried out recently on new alpha -emitters. The results obtained are analysed with a view to finding the degree of correspondence, or disagreement, with the authors' own ideas about alpha -decay processes. The discussion is confined to examining even isotopes of polonium, radon, radium and thorium Several theoretical and experimental plots are given of reduced widths of alpha -disintegration for different regions of shell filling and a comparison is made between barrier penetration coefficients, obtained by rigorous methods and with the aid of WKB- approximation, for /sup 212/Po, /sup 208/Po and /sup 212/Po isotopes. (24 refs).

Determination of spatial and energy distributions of neutrons in experiments on transmutation of radioactive waste using relativistic protons

CERN Document Server

Zhuk, I V; Boulyga, S F; Kievitskaia, A I; Rakhno, I L; Chigrinov, S E; Bradnova, V; Krivopustov, M I; Kulakov, B A; Brandt, R; Ochs, M; Wan, J S

1999-01-01

The experiments on transmutation of sup 1 sup 2 sup 9 I and sup 2 sup 3 sup 7 Np using uranium-lead targets surrounded by a paraffin moderator were performed at the Joint Institute for Nuclear Research (JINR, Russia). The targets were irradiated by 1.5 GeV and 7.4 GeV protons at the Synchrophasotron of JINR. In the frame of present work spatial and energy distributions of neutrons on the surface of the paraffin moderator were measured using SSNTD technique. It is shown that measured values of spectral indices do not depend on the energy of incident protons but depend on the target composition. The presence of the uranium insertion softens neutron spectra.

Neutron Production in Spallation Reactions of 0.9 and 1.5 GeV Protons on a Thick Lead Target. Comparison between Experimental Data and Monte-Carlo Simulations

CERN Document Server

Krasa, A; Bradnova, V; Caloun, P; Chultem, D; Henzl, V; Henzlová, D; Kalinnikov, V G; Krivopustov, M I; Krízek, F; Kugler, A; Majerle, M; Solnyshkin, A A; Stegailov, V I; Tsoupko-Sitnikov, V M; Tumendelger, T; Vasilev, S I; Wagner, V; Nuclear Physics Institute of Academy of Sciences of Czech Republic, Rez, Czech Republic

2005-01-01

This paper reports on two experiments performed at the Synchrophasotron/Nuclotron accelerator complex at JINR. Relativistic protons with energies 885 MeV and 1.5 GeV hit a massive cylindrical lead target. The spatial and energetic distributions of the neutron field produced by the spallation reactions were measured by the activation of Al, Au, Bi, Co, and Cu foils placed on the surface of the target and close to it. The yields of the radioactive nuclei produced by threshold reactions in these foils were determined by the analyses of their $\\gamma$ spectra. The comparison with Monte-Carlo based simulations was performed both with the LAHET+MCNP code and the MCNPX code.

Neutron production in spallation reactions of 0.9 and 1.5 GeV protons on a thick lead target. Comparison between experimental data and Monte-Carlo simulations

International Nuclear Information System (INIS)

Krasa, A.; Krizek, F.; Wagner, V.; Kugler, A.; Henzl, V.; Henzlova, D.; Majerle, M.; Adam, J.; Caloun, P.; Bradnova, V.; Chultem, D.; Kalinnikov, V.G.; Krivopustov, M.I.; Solnyshkin, A.A.; Stegajlov, V.I.; Tsupko-Sitnikov, V.M.; Tumehndehlgehr, Ts.; Vasil'ev, S.I.

2005-01-01

This paper reports on two experiments performed at the Synchrophasotron/Nuclotron accelerator complex at JINR. Relativistic protons with energies 885 MeV and 1.5 GeV hit a massive cylindrical lead target. The spatial and energetic distributions of the neutron field produced by the spallation reactions were measured by the activation of Al, Au, Bi, Co, and Cu foils placed on the surface of the target and close to it. The yields of the radioactive nuclei produced by threshold reactions in these foils were determined by the analyses of their γ spectra. The comparison with Monte-Carlo based simulations was performed both with the LAHET+MCNP code and the MCNPX code

Particles and nuclei, letters, in Russian, pt.4

CERN Document Server

2002-01-01

The present collection of letters from JINR, Dubna, contains nine separate records on thermal multifragmentation, nuclear fog and critical temperature for the liquid-gas phase transition, topological and nontopological solutions for the chiral bag model with constituent quarks, comparison of ATLAS tilecal module No. 8 high-precision metrology measurement results obtained by laser (JINR) and photogrammetric (CERN) methods, calibration of the beam polarimeter at the JINR synchrophasotron, anomalous A-, t-dependence and the phase behaviour of partial wave of coherent production of radial state pi (1300), about some inverse problems of nuclear physics, the nuclear matter modification at intermediate energies, experimental research of the NN scattering with polarized particles at the VdG accelerator of Charles university. Project 'NN interactions' and the forward detector of the ANKE spectrometer. Scintillation and Cherenkov hodoscopes

High magnetic field uniformity superconducting magnet for a movable polarized target

International Nuclear Information System (INIS)

Anishchenko, N.G.; Bartenev, V.D.; Blinov, N.A.

1998-01-01

The superconducting polarizing magnet was constructed for movable polarized target (MPT) with working volume 200 mm long and 30 mm in diameter. The magnet provides a polarizing magnetic field up to 6 T with the uniformity of 4.5 x 10 -4 in the working volume of the target. The magnet windings are made of a NbTi wire, impregnated with the epoxy resin and placed in the horizontal cryostat with 'warm' aperture diameter of 96 mm. The design and technology of the magnet winding are described. Results of the magnetic field map measurements using a NMR-magnetometer are given. The MPT set-up is installed in the beam line of polarized neutrons produced by break-up of polarized deuterons extracted from the Synchrophasotron of the Laboratory of High Energies (LHE), JINR, Dubna

Transmutation studies using SSNTD and radiochemistry and the associated production of secondary neutrons

CERN Document Server

Brandt, R; Wan, J S; Schmidt, T; Langrock, E J; Vater, P; Adam, J; Bamblevski, V P; Bradnova, V; Gelovani, L K; Kalinnikov, V K; Krivopustov, M I; Kulakov, B A; Sosnin, A N; Perelygin, V P; Pronskikh, V S; Stegailov, V I; Tsoupko-Sitnikov, V M; Modolo, G; Odoj, R; Philippen, P W; Adloff, J C; Pape, F; Debeauvais, M; Zamani-Valassiadou, M; Hashemi-Nezhad, S R; Dwivedi, K K; Guo Shi Lun; Li, L; Wang, Y L; Wilson, B

1999-01-01

Experiments using 1.5 GeV, 3.7 GeV and 7.4 GeV protons from the Synchrophasotron, LHE, JINR, Dubna, Russia, on extended Pb- and U- targets were carried out using SSNTD and radiochemical sensors for the study of secondary neutron $9 fluences. We also carried out first transmutation studies on the long-lived radwaste nuclei /sup 129/I and /sup 237/Np. In addition, we carried out computer code simulation studies on these systems using LAHET and DCM/CEM codes. We $9 have difficulties to understand rather large transmutation rates observed experimentally when they are compared with computer simulations. There seems to be a rather fundamental problem understanding the large transmutation rates as $9 observed experimentally in Dubna and CERN, as compared to those theoretical computer simulations mentioned above. (10 refs).

First experiments on transmutation studies of iodine-129 and neptunium-237 using relativistic protons of 3.7 GeV

International Nuclear Information System (INIS)

Krivopustov, M.I.; Adam, J.; Bradnova, V.

1997-01-01

First experiments on the transmutation of long-lived 129 I and 237 Np using relativistic protons of 3.7 GeV are described. Relativistic protons generate in extended Pb-targets substantial neutron fluences. These neutrons get moderated in paraffin and are used for transmutation as follows: 129 (n, γ) 130 I(β - ) → 130 Xe(stable) and 237 Np(n, γ) 238 Np(β - ) →. The isotopes 130 I (T 1/2 =12.36 h) and 238 Np (T 1/2 =2.117 days) were identified radiochemically. One can estimate the transmutation cross section (n, γ) in the given neutron field as σ( 129 I(n, γ))=(10±2)b and σ( 237 Np(n, γ))=(140±30)b. The experiments were carried out in November 1996 at the Synchrophasotron, Laboratory of High Energies (LHE), Dubna, Russia

The United Nuclear Research Institute

International Nuclear Information System (INIS)

Kiss, D.

1978-01-01

The UNRI, the only common institute of the socialist countries was founded in 1956 in Dubna. The scientists of small countries have the opportunity to take part in fundamental research with very expensive devices which are usually not available for them. There are six research laboratories and one department in the UNRI namely: the theoretical physical laboratory; the laboratory of high energies - there is a synchrophasotron of 1a GeV there; the laboratory of nuclear problems - there is a synchrocyclotron of 680 MeV there; the laboratory of nuclear reactions with the cyclotron U-300 which can accelerate heavy ions; the neutronphysical laboratory with the impulse reactor IBM-30; the laboratory of computation and automatization with two big computers; the department of new acceleration methods. The main results obtained by Hungarian scientist in Dubna are described. (V.N.)

Experience gained during 10 years transmutation experiments in Dubna

Science.gov (United States)

Zamani, M.; Fragopoulou, M.; Manolopoulou, M.; Stoulos, S.; Brandt, R.; Westmeier, W.; Krivopustov, M.; Sosnin, A.; Golovatyuk, S.

2006-05-01

Transmutation, the procedure of transforming long-lived radioactive isotopes into stable or short-lived, was proposed for reducing the amount of radioactive waste resulting from technological applications of nuclear fission. The Accelerator Driven Systems (ADS) provide the possibility to generate intense neutron spectrum yielding in an effective transmutation of unwanted isotopes. Such experiments are being carried out for the last 10 years in Synchrophasotron / Nuclotron accelerators at the Veksler-Baldin Laboratory of High Energies of the Joint Institute for Nuclear Research in Dubna, Russia. Thick Pb and Pb-U targets, surrounded by moderators, have been irradiated by protons in the energy range of 0.5-7.4 GeV. Neutron fluence measurements have been performed by different techniques of passive detectors (neutron activation detectors, solid state nuclear track detectors). Transmutation of 129I, 237Np, 239Pu was studied. The results of these experiments are presented and discussed.

Joint annual report 1984

International Nuclear Information System (INIS)

Hennig, K.

1985-06-01

An account is given on the activities in nuclear and solid state physcis. In the field of relativistic nuclear physcis first measurements at the Synchrophasotron of the JINR Dubna are presented. Nuclear reactions with heavy ions have been investigated at the cyclotron U-300 of the JINR. Studies of few-nucleon problems and measurements of fission cross sections at the tandem accelerator at Rossendorf have been continued. High spin states in transition nuclei (A approximately 80) and semimagic nuclei have been studied. Works in nuclear theory comprise heavy ion physics, plasma transitions in hot nuclear matter, antikaon production, hypernuclei and deformed nuclei, the time-dependent Hartree-Fock method, meson exchange, and new aspects of shell models. Various studies in solid state physics are presented, including the following: high-dose implantation in metals and semiconductors, tempering in semiconductor materials, light pulse annealing in Si, neutron diffraction in texture analysis, application of Si in the field of sensor technology

Investigation of Neutron Spectra and Transmutation of ^{129}I, ^{237}Np and Other Nuclides with 1.5 GeV Protons from the Dubna Nuclotron Using the Electronuclear Setup "Energy plus Transmutation"

CERN Document Server

Krivopustov, M I; Balabekyan, A R; Batusov, Yu A; Bielewicz, M; Brandt, R; Chaloun, P; Chultem, D; Dwivedi, K K; Elishev, A F; Fragopoulou, M; Henzl, V; Henzlová, D; Kalinnikov, V G; Kievets, M K; Krása, A; Krizek, F; Kugler, A; Manolopoulou, Metaxia; Mariin, I I; Nourreddine, A; Odoj, R; Pavliouk, A V; Pronskikh, V S; Robotham, H; Siemon, K; Szuta, M; Stegailov, V I; Solnyshkin, A A; Sosnin, A N; Stoulos, S; Tsoupko-Sitnikov, V M; Tumendelger, T; Wojecehowski, A; Wagner, V; Wan, J S; Westmeier, W; Zamani-Valasiadou, M; Kumawat, H; Kumar, V; Zaverioukha, O S; Zhuk, I V

2004-01-01

Experiments which are part of the scientific program "Investigations of physical aspects of electronuclear method of energy production and transmutation for radioactive waste of atomic energetics using relativistic beams from the JINR Synchrophasotron/Nuclotron" (project "Energy plus Transmutation") are described. A large lead target surrounded by a four-section uranium blanket with total weight of 206.4 kg natural uranium was irradiated with 1.5 GeV protons from the new cryogenic accelerator Nuclotron. Radiochemical sensors were exposed to the secondary particle fluences inside and on top of the target assembly. Two long-lived radioactive waste of atomic energetics sensors ^{129}I and ^{237}Np (approximately 1 g weight each) and stable nuclides ^{27}Al, ^{59}Co, ^{127}I, ^{139}La, ^{197}Au and ^{209}Bi as well as natural and enriched uranium were used. In addition, various solid state nuclear track detectors and nuclear emulsions were exposed simultaneously. The experimental results confirm the theoretical e...

Transmutation of $^{239}$Pu and Other Nuclides Using Spallation Neutrons Produced by Relativistic Protons Reacting with Massive U- and Pb-Targets

CERN Document Server

Adam, J; Bamblevski, V P; Barabanov, M Yu; Bradnova, V; Chaloun, P; Hella, K M; Kalinnikov, V G; Krivopustov, M I; Kulakov, B A; Perelygin, V P; Pronskikh, V S; Pavliouk, A V; Solnyshkin, A A; Sosnin, A N; Stegailov, V I; Tsoupko-Sitnikov, V M; Zaverioukha, O S; Adloff, J C; Debeauvais, M; Brandt, R; Langrock, E J; Vater, P; Van, J S; Westmeier, W; Dwivedi, K K; Guo Shi Lun; Li Li Qiang; Hashemi-Nezhad, S R; Kievets, M K; Lomonosova, E M; Zhuk, I V; Modolo, G; Odoj, R; Zamani-Valassiadou, M

2001-01-01

Experimental studies on the transmutation of some long-lived radioactive waste nuclei, such as ^{129}I, ^{237}Np, and ^{239}Pu, as well as on natural uranium and lanthanum (all of them used as sensors) were carried out at the Synchrophasotron of the Laboratory for High Energies (JINR, Dubna). Spallation neutrons were produced by relativistic protons with energies in the range of 0.5 GeV\\le E(p)\\le 1.5 GeV interacting with 20 cm long uranium or lead target stacks. The targets were surrounded by 6 cm paraffin moderators. The radioactive sensors mentioned above were positioned on the outside surface of the moderator and contained typically approximately 0.5 up to 1 gram of long-lived isotopes. The highly radioactive targets were produced perfectly well-sealed in aluminum containers by the Institute of Physics and Power Engineering, Obninsk, Russia. From the experimentally observed transmutation rates one can easily extrapolate, that in a subcritical nuclear power assembly (or "energy amplifier") using a 10 mA pr...

Transmutation of radioactive waste with the help of relativistic heavy ions

International Nuclear Information System (INIS)

Brandt, R.; Wan, J.S.; Ochs, M.

1997-01-01

A series of experiments was carried out at the Synchrophasotron, LHE, JINR, Dubna, using 3.67 GeV protons and 18 GeV 12 C ion beams. Two massive lead and uranium targets surrounded by paraffin moderator were irradiated. The outer surface of the moderator was some small U- and La-sensors, to be studied by radiochemistry activation techniques, and also by solid-state nuclear track detectors. Both experimental techniques independently give approximately 28 low energy neutrons on the outer surface of the moderator per 3.67 GeV proton hitting the Pb-target. Theoretical estimations based on LAHET and DCM/CEM computer codes give considerably smaller fluences: approximately 7-9 low energy neutrons ( 129 I(T 1/2 =2.4 days), could be identified radiochemically as well as other spallation products. The transmutation rates are substantial: a 10 mA accelerator of 3.67 GeV protons could transmute at least 30% of 237 Np and 1% of 129 I per month under the given geometrical conditions

Anomalons, recent copper-target experiments and the first law of thermodynamics

International Nuclear Information System (INIS)

Brandt, R.; Khan, H.A.; Krivopustov, M.I.

1991-01-01

A reanalysis of the old Alexander experiment, reporting on the anomalous behavior of pie in K-decays indicates that this anomalous behavior may be connected to a state of lower entropy or in other words to 'anomalous information', considering the well-known relation: negative entropy information. Now, recent copper-target experiments from the Synchrophasotron entail, that the wide-angle emission of hadrons in the reaction (44 GeV/sup 12/c + Cu) cannot be understood with concepts of physics, as known to the authors. However, this could be understood with 'anomalous information'. Further effects of this 'anomalous information' may be obtained in future studies with very massive heavy element targets irradiated with relativistic ions. The total production of neutrons in such a system could both be measured experimentally and calculated theoretically. As the calculations are based on the 1st Law of Thermodynamic, a significant excess of neutron fluxes beyond calculations may indicate the effete of anomalous information, even on the expense of the 1st law of Thermodynamics. (Orig./A.B.)

Superconducting polarizing magnet for a movable polarized target

International Nuclear Information System (INIS)

Anishchenko, N.G.; Bartenev, V.D.; Blinov, N.A.

1998-01-01

The superconducting polarizing magnet was constructed for the JINR (Dubna) movable polarized target (MPT) with working volume 200 mm long and 30 mm in diameter. The magnet provides a polarizing magnetic field up to 6 T in the centre with the uniformity of 4.5 x 10 -4 in the working volume of the target. The magnet contains a main solenoidal winding 558 mm long and 206/144 mm in diameters, and compensating and correcting winding placed at its ends. The windings are made of a NbTi wire, impregnated with the epoxy resin and placed in the horizontal cryostat. The diameter of the 'warm' aperture of the magnet cryostat is 96 mm. The design and technology of the magnet winding are described. Results of the magnetic field map measurements, using a NMR-magnetometer are given. A similar magnet constructed at DAPNIA, CEA/Saclay (France), represented a model for the present development. The MPT array is installed in the beam line of polarized neutrons produced by break-up of polarized deuterons extracted from the synchrophasotron of the Laboratory of High Energies (LHE), JINR (Dubna)

Polarization experiments with hadronic and electromagnetic probes

International Nuclear Information System (INIS)

Punjabi, V.

1993-01-01

The following research activities were carried out during the past year Calibration of focal plane polarimeter POMME up to 2.4 GeV at Saturne National Laboratory (LNS) in Saclay. Measurement of tensor analyzing power T 20 and polarization transfer κ 0 at Saturne up to 2.1 GeV in elastic backward dp scattering rvec dp → rvec pd. Measurement of tensor analyzing power T 20 at synchrophasotron in Dubha up to 4.4 Gev in elastic backward dp scattering rvec dp → pd. Resubmission of conditionally Approved G EP proposal 89-14 at CEBAF. Start construction of focal plane polarimeter (FPP) for CEBAF hall A hadron spectrometer. The planned work for the next year includes: Construction of FPP for CEBAF hall A hadron spectrometer; measurement of polarization transfer κ 0 and tensor analyzing power T 20 in elastic backward dp scattering at Saturne; measurements of tensor analyzing power in 1 H( 6 Li,d)X, 1 H( 6 Li,α)X, 1 H( 6 Li,t)X and 1 H( 6 Li, 3 He)X reactions at Saturne; and study of polarization transfer in 2 H(rvec e,e'rvec p)n reaction at Bates

Measurements of the np total cross section difference ΔσL at 1.59,1.79 and 2.20 GeV

International Nuclear Information System (INIS)

Sharov, V.I.; Zaporozhets, S.A.

2000-01-01

New results of the neutron-proton spin-dependent total cross section difference Δσ L (np) at the neutron beam kinetic energies 1.59,1.79 and 2.20 GeV are presented. Measurements were performed at the Synchrophasotron of the Laboratory of High Energies of the Joint Institute for Nuclear Research in Dubna. A quasi-monochromatic neutron beam was produced by break-up of extracted polarized deuterons. Neutrons were transmitted through a large polarized proton target. Measurements were performed either with a parallel or an antiparallel beam and target polarizations, both oriented along the beam momentum. The results at the two higher energies were measured with two opposite beam and target polarization directions. Only one target polarization direction was available at 1.59 GeV. The present measurements agree well with existing data. A fast decrease of the -Δσ L (np) values with increasing energy above 1.1 GeV was confirmed. The new results are also compared with model predictions and with phase shift analysis fits. The Δσ L quantities for the isosinglet state I=0, deduced from the measured Δσ L (np) values and known Δσ L (pp) data, are given. (orig.)

Experimental problems of search for quark-gluon plasma in nucleus-nucleus interactions

International Nuclear Information System (INIS)

Okonov, Eh.O.

1987-01-01

Experimental problems for searching for quark-gluon (quagma) plasma in nucleus-nucleus interactions (NbNb,CaCa, ArPb, CnE, ONe) in the energy range E=0.4-1 GeV/A and 3.67 GeV/A and 200 GeV/A energies are discussed. Peculiarities of performing experiments on Dubna synchrophasotron and SPS Bevalac are discussed. The first results prove hadron matter thermalization sufficient for quagma manifestation. It is found that such characteristics of studied interactions as relative λ-hyperon yield, spectral (temperature) characteristics of λ k -hyperons (with higher values of transferred transverse momenta) and associatively produced peons are of greatest interest. The necessity of precise establishment of λ-hyperon group as excessive and differing in its origin from the other particles of the hadron phase is noted. It is shown that experimental approach used in Dubna research proved efficient and requires further development. It includes : selection of rare events (fluctuations) in central interactions of nuclei with high local excitation; search and research of peculiarities in the production of strange particles and in associative pion production; use of streamer spectrometer with a trigger system of rigid selection of central interactions

Proton spectra from 6.3 GeV/c deuteron break-up on H, D, C, Al and Bi nuclei

International Nuclear Information System (INIS)

Azhgirey, L.S.; Ignatenko, M.A.; Ivanov, V.V.; Kuznetsov, A.S.; Mescheryakov, M.G.; Razin, S.V.; Stoletov, G.D.; Vzorov, I.K.; Zhmyrov, V.N.

1977-01-01

The proton spectra from deuteron break-up on H, D, 12 C, 27 Al and 209 Bi nuclei were measured at an angle of 103 mrad (lab. system) in the momentum interval from 2.6 to 3.6 GeV/c. The measurements were made at the JINR synchrophasotron by one-arm magnetic spectrometer on-line with a computer. The extracted 6.3 GeV/c deuteron beam was incident on targets of CH 2 , CD 2 , C, Al and Bi at the thickness from 0.8 to 2 g/cm 2 . The flux of deuteron beam was equal to 5x10 8 -5x10 9 particles/pulse with a typical pulse length of 300 ms. The repetition rate was one pulse every 10 s. Proton peaks with the maximum at about 3.1 GeV/c and 280-300 MeV/c FWHM dominate in all the measured spectra. Experimental proton spectra are compared with calculations with the Reid, the Moravcsik Gartenhaus, the Hulten and the Gauss wave functions. The results, on the whole, are reasonably reproduced in the framework of the Glauber multiple scattering model taking into account the relativistic deformation of the deuteron wave function

The identification method of the nuclear fragments in emulsions

International Nuclear Information System (INIS)

Jipa, Alexandru; Ocheseanu, Silvia; Caramarcu, Costin; Calin, Marius; Constantin, Florin; Stan, Emil

2003-01-01

The visualization detectors have been successfully used from the beginning of the study of the relativistic nuclear collisions. One of these detectors used in such experiments is the nuclear emulsion. To increase the speed of the passage from pictures to experimental data different methods and tools have been proposed during the time. For identifying the nuclear fragments obtained in the relativistic radioactive beams multiple layers of nuclear emulsions have been exposed in experiments performed at the Synchrophasotron from the JINR Dubna (BECQUEREL Collaboration). The nuclear fragments have been identified using PAVICOM scanning and measuring system. In the present work an identification method based on a real time image processing machine and a reconstruction algorithm based on special conformal transforms is proposed. The results obtained by this method are compared with those obtained using PAVICOM device. Because in this study only pictures have been used, not initial nuclear emulsions, some difficulties in the identification of the nuclear fragments with higher polar angles can appear. Generally, comparable results have been obtained. The authors thank Dr. Pavel Zarubin from JINR Dubna, Laboratory of High Energy Physics, and Dr. Maria Haiduc, Institute of Space Sciences Bucharest-Magurele, for the pictures of the nuclear emulsions exposed in these experiments. (authors)

Further evidences for enhanced nuclear cross-sections observed in 44 GeV carbon ion interactions with copper

International Nuclear Information System (INIS)

Brandt, R.; Abdullaev, I.G.; Adloff, J.C.

1995-01-01

The work of enhanced nuclear cross-sections of secondary fragments produced in the interaction of 44 GeV 12 C with copper has been deepened and extended. The earlier experiment on the emission of secondary fragments into large angles producing enhanced amounts of 24 Na in copper (Phys. Rev. C, 45, 1194(1992)) was confirmed and refined both experimentally and theoretically. In this context, one looked for another signature of such enhanced production, namely for enhanced neutron production. In order to search for this, a 20 cm thick massive copper target was irradiated with 18 and 44 GeV 12 C-ions. Secondary fragments already described could interact again with copper. Outside the metallic target, secondary neutrons got moderated and low energy nuclear reactions were studied in La and U radiochemically via (n,γ)-reactions and also with various solid state nuclear track detectors. One observed an indication, however not yet significant, of enhanced production rates for low energy nuclear reactions only with 44 GeV 12 C, when compared to 18 GeV 12 C-ions. Besides some proton irradiations at SATURNE, Saclay (France) at 2.6 GeV and at PSI, Villigen (Switzerland) at 0.6 GeV all other irradiations were carried out at the Synchrophasotron, LHE, JINR, Dubna (Russia). 46 refs., 14 figs., 8 tabs

Transmutation of 239Pu and other nuclides using spallation neutrons produced by relativistic protons reacting with massive U- and Pb- targets

International Nuclear Information System (INIS)

Adam, J.; Balabekyan, A.; Bamblevskij, V.P.

2001-01-01

Experimental studies on the transmutation of some long-lived radioactive waste nuclei, such as 129 I, 237 Np, and 239 Pu, as well as on natural uranium and lanthanum (all of them used as sensors) were carried out at the Synchrophasotron of the Laboratory of High Energies (JINR, Dubna). Spallation neutrons were produced by relativistic protons with energies in the range of 0.5 GeV ≤ E(p) ≤ 1.5 GeV interacting with 20 cm long uranium or lead target stacks. The targets were surrounded by 6 cm paraffin moderators. The radioactive sensors mentioned above were positioned on the outside surface of the moderator and contained typically approximately 0.5 up to 1 gram of long-lived isotopes. The highly radioactive targets were produced perfectly well-sealed in aluminium containers by the Institute of Physics and Power Engineering, Obninsk, Russia. From the experimentally observed transmutation rates one can easily extrapolate, that in a subcritical nuclear power assembly (or 'energy amplifier') using a 10 mA proton beam of 1 GeV onto a Pb-target as used here, one can transmute in one gram samples of the isotope within one month about 3 mg 129 I, 21 mg 237 Np, 3.3 mg 238 U, and 200 mg 239 Pu under the same geometrical conditions. Our observations show, that the transmutation ability of our system increases linearly with the proton energy within the energy interval studied

First radiochemical studies on the transmutation of 239Pu with spallation neutrons

International Nuclear Information System (INIS)

Wan, J.-S.; Langrock, E.-J.; Westmeier, W.

2000-01-01

Incineration studies of plutonium were carried out at the synchrophasotron of the Joint Institute for Nuclear Research (Dubna) using proton beams with energies of 0.53 GeV and 1.0 GeV. Solid lead target (8 cm in diameter and 20 cm long) was surrounded with 6 cm thick paraffin as neutron moderator and then irradiated. The transmutation of 239 Pu and the associated production of fission products 91 Sr, 92 Sr, 97 Zr, 99 Mo, 103 Ru, 105 Ru, 129 Sb, 132 Te, 133 I, 135 I and 143 Ce were studied. The plutonium samples (each 449 mg) were placed on the outer surface of moderator. For 1.0 GeV proton beam, the fission rate of 239 Pu is 0.0032 fissions per proton in one gram plutonium samples, for 0.53 GeV proton this value is 0.0022. The experimental uncertainty is about 15%. The experiments are compared to two theoretical model calculations with moderate success, using the Dubna Cascade Model (CEM) and the LAHET code. The practical incineration rate of 239 Pu is very high. For example: if one uses 10mA, 1 GeV proton beams under the same (fictive) experimental conditions, the incineration rate of 239 Pu via fission is 3 mg out of the 449 mg sample per day. For 0.53 GeV protons the corresponding rate is 2 mg per day

Coherent fragmentation of 12C nuclei of momentum 4.5 GeV/ c per nucleon through the 8Beg.s.+4He channel in a nuclear photoemulsion containing lead nuclei

Science.gov (United States)

Belaga, V. V.; Gerasimov, S. G.; Dronov, V. A.; Peresadko, N. G.; Pisetskaya, A. V.; Rusakova, V. V.; Fetisov, V. N.; Kharlamov, S. P.; Shesterkina, L. N.

2017-07-01

A two-particle channel in which an unbound nucleus of 8Be in the ground state (8Beg.s.) was one of the fragments was selected among events where 12C nuclei of momentum 4.5 GeV/c per nucleon undergo coherent dissociation into three alpha particles. The events in question were detected in a track nuclear photoemulsion containing lead nuclei, which was irradiated at the synchrophasotron of the Laboratory of High Energies at the Joint Institute for Nuclear Research (JINR, Dubna). The average transverse momentum of alpha particles produced upon the decay of 8Beg.s. nuclei was 87±6 MeV/ c, while that for "single" alpha (αs) particles was 123±15 MeV/ c. The average value of the transverse-momentum transfer in the reaction being considered, Pt(12C), was 223 ± 20 MeV/ c. The average value of the cross section for this channel involving Ag and Br target nuclei was 13 ± 4 mb, while the cross section for the reaction on the Pb nucleus was 40 ± 15 mb. The Coulomb dissociation contribution evaluated on the basis of the number of events where the momentum P t(12C) did not exceed 0.1 GeV/c saturated about 20%. In nine events, the measured total transverse energy of the fragments in the reference frame comoving with the decaying carbon nucleus did not exceed 0.45 MeV, which did not contradict the excitation of the participant 12C nucleus to the level at 7.65 MeV. The average value of the transverse momentum in those events was 234 ± 25 MeV/ c.

DUBNA: Spin effects

International Nuclear Information System (INIS)

Anon.

1995-01-01

Full text: Earlier this year, a collaboration of Russian, Ukrainian and French laboratories measured the difference between the polarized neutron and proton total reaction rate (total cross section difference) at slightly higher energies than previous experiments, providing an interesting hint of an effect predicted by theory. This was measured using a beam of longitudinally polarized neutrons and a longitudinally polarized proton target with parallel and antiparallel polarization directions. The polarized neutron beam, from the break-up of polarized deuterons, was accelerated by the Synchrophasotron at the Joint Institute for Nuclear Research (JINR) Laboratory of High Energies, Dubna (Russian Federation). The polarized target, 20 cm long and 3 cm in diameter, provided by DAPNIA (Saclay, France) and Argonne (USA), had also been used in 1989-1990 at Fermilab for the E704 experiment. Equipment from Saclay and Argonne was shipped to Dubna and work started in June 1994. The International Association for the Promotion of Cooperation with Scientists from the Independent States of the Former Soviet Union (INTAS) supported the construction and improvement of the target in a suitable transportable form. The target was mounted in the JINR Laboratory of Nuclear Problems (LNP) by experts from DAPNIA (Saclay), JINR Dubna (LNP, LHE and Laboratory of Particle Physics - LPP), Gatchina (Russia), RASMoscow and the Kharkov (Ukraine) laboratories. The Saturne National Laboratory (Saclay), helped with computer programmes for the NMR target polarization measurements. Apparatus was tested in early February. The beam of 2 x 109 polarized deuterons produced 106 polarized neutrons at 3.6 GeV. The neutron beam polarization was about 52%. The new superconducting Nuclotron accelerator should allow the beam intensity to be increased and beam quality improved after an upgrade of the injection system. Preliminary results for the polarized neutron-proton cross section difference at neutron kinetic

Accelerator-Based Studies of Heavy Ion Interactions Relevant to Space Biomedicine

Science.gov (United States)

Miller, J.; Heilbronn, L.; Zeitlin, C.

1999-01-01

Evaluation of the effects of space radiation on the crews of long duration space missions must take into account the interactions of high energy atomic nuclei in spacecraft and planetary habitat shielding and in the bodies of the astronauts. These heavy ions (i.e. heavier than hydrogen), while relatively small in number compared to the total galactic cosmic ray (GCR) charged particle flux, can produce disproportionately large effects by virtue of their high local energy deposition: a single traversal by a heavy charged particle can kill or, what may be worse, severely damage a cell. Research into the pertinent physics and biology of heavy ion interactions has consequently been assigned a high priority in a recent report by a task group of the National Research Council. Fragmentation of the incident heavy ions in shielding or in the human body will modify an initially well known radiation field and thereby complicate both spacecraft shielding design and the evaluation of potential radiation hazards. Since it is impractical to empirically test the radiation transport properties of each possible shielding material and configuration, a great deal of effort is going into the development of models of charged particle fragmentation and transport. Accurate nuclear fragmentation cross sections (probabilities), either in the form of measurements with thin targets or theoretical calculations, are needed for input to the transport models, and fluence measurements (numbers of fragments produced by interactions in thick targets) are needed both to validate the models and to test specific shielding materials and designs. Fluence data are also needed to characterize the incident radiation field in accelerator radiobiology experiments. For a number of years, nuclear fragmentation measurements at GCR-like energies have been carried out at heavy ion accelerators including the LBL Bevalac, Saturne (France), the Synchrophasotron and Nuklotron (Dubna, Russia), SIS-18 (GSI, Germany), the

On the possibility of the geometrical reconstruction of the charged particle trajectories in the streamer chamber

International Nuclear Information System (INIS)

Constantin, F.; Jipa, A.; Ilie, Gh.

1998-01-01

An interesting problem in the experiments using visualisation detectors is that of the geometrical reconstruction of the trajectories. In this work a new method for the geometrical reconstruction of trajectories of the charged particles produced in nucleus-nucleus collisions at 4.5 A GeV/c is proposed. The experiments have been performed at the JINR Synchrophasotron, in the frame of the SKM 200 Collaboration. The geometrical reconstruction method is based on the facilities offered by the Sun3VME-MaxVideo20 work-station, a real time image processing machine produced by DataCube Corporation. An algorithm is constructed taking into account some relevant characteristics of the pictures. For a typical picture, the centre, a very noisy region, is the starting point for all main tracks (the vertex); the poor contrast makes tracks identification difficult. Surrounding this first region there is an almost circular belt with a better contrast and without overlapping tracks. Finally, the third region, the outer one, is the origin of the secondary tracks, which is also noisy. The secondary tracks identify particles created in the chamber far from the vertex; secondary particle creation induces a large noise into the image and the sharpness reduces. The areas of these three regions vary from one picture to other, their fractions amounting around 20%, 50%, and 30%, respectively. The algorithm treats the primary tracks only. It takes great advantage for the well-defined geometrical vertex position. The primary tracks represent curved trajectories of charged particles moving in a magnetic field. As curved tracks are harder to identify relative to straight lines, we propose a conformal transformation from the surface z = x + iy to the surface w = u + iv related by the relation z a 2 /w. It transforms circles passing through origin in z plane into straight lines in w plane. The a 2 factor is a constant which must be determined. Practically, we transform a discrete image by