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Sample records for bakelite

  1. Study of Performance of Bakelite Resistive Plate Chamber (RPC)

    CERN Document Server

    Ganai, R; Roy, A; Muduli, B; Chattopadhyay, S; Ahammed, Z; Das, G; Ramnarayan, S

    2016-01-01

    Resistive Plate Chamber (RPC) is a type of gaseous detector having excellent time and position resolutions. VECC is involved in the R\\&D of indigenously developed bakelite RPCs. The largest size of bakelite RPC developed in India is 100 cm $\\times$ 100 cm. We present here the test results of a bakelite sample along with the cosmic ray test results of a bakelite RPC (30 cm $\\times$ 30 cm $\\times$ 0.2cm) fabricated at VECC. The steps taken towards the development of a large size (240 cm $\\times$ 120 cm $\\times$ 0.2 cm) bakelite RPC have also been discussed.

  2. Study of Performance of Bakelite Resistive Plate Chamber (RPC)

    OpenAIRE

    Ganai, R.; Agarwal, K.; Roy, A; Muduli, B.; Chattopadhyay, S; Ahammed, Z.; G Das; Ramnarayan, S.

    2016-01-01

    Resistive Plate Chamber (RPC) is a type of gaseous detector having excellent time and position resolutions. VECC is involved in the R\\&D of indigenously developed bakelite RPCs. The largest size of bakelite RPC developed in India is 100 cm $\\times$ 100 cm. We present here the test results of a bakelite sample along with the cosmic ray test results of a bakelite RPC (30 cm $\\times$ 30 cm $\\times$ 0.2cm) fabricated at VECC. The steps taken towards the development of a large size (240 cm $\\times...

  3. Recycling Waste Bakelite As A Carbon Resource In Ironmaking

    Directory of Open Access Journals (Sweden)

    James Ransford Dankwah

    2015-02-01

    Full Text Available Abstract Bakelite is a 3-dimensional cross-linked network structured thermosetting polymer which is difficult to recycle after use. However it contains high levels of carbon and CaCO3 that can be recovered for use as reductant and fluxing agent in ironmaking. In this work we report the use of post-consumer bakelite as reductant for the production of metallic iron from iron oxide in a horizontal tube furnace through the composite pellet approach.Gas emission studies were conducted by pyrolysing raw bakelite at different temperatures within the temperature range 1200-1600 C in a horizontal tube furnace. Following thiscomposite pellets were then formed from mixtures of iron oxide and post-consumer bakelite.The iron oxide-bakelite composites were heated from room temperature to 1200 C and then between 1200-1600 C in a continuous stream of pure argon and the off gas was analysed continuously using an infrared IR gas analyser. Elemental analyses of samples of the reduced metal were performed chemically for its oxygen content using a LECO oxygennitrogen analyser. The extent of reduction after ten minutes was determined from the oxygen content. Gas emission studies revealed the emission of large volumes of the reductant gases CO and CH4along with CO2.It is further demonstrated that post-consumer bakelite is effective at reducing iron oxide to produce metallic iron.

  4. Study of Glass and Bakelite Properties as Electrodes in RPC

    CERN Document Server

    Manisha,; Shahi, J S

    2016-01-01

    India-based Neutrino Observatory (INO) collaboration is planning to build a magnetized Iron-CALorimeter detector (ICAL) for the study of atmospheric neutrinos. ICAL detector consists of 151 layers of magnetized iron plates interleaved with Resistive Plate Chambers (RPCs) as active detector elements with a total mass of 50 kton. Resistive Plate Chambers are gaseous detectors made up of two parallel electrodes of high bulk resistivity like float glass and bakelite. These detectors are extensively used in several high energy physics experiments since 1980s because of high count rate, excellent time as well as spatial resolutions, simple to fabricate and operate. Due to detector aging issue, it is necessary to characterize electrode material so as to select appropriate electrode material before fabricating the detector. In the present studies, we measured bulk resistivity and surface current of glass as well as bakelite. Bulk resistivity of bakelite is ~ 100 times less than that of glass and surface current of ba...

  5. Influence of Temperature and Humidity on Bakelite Resistivity

    CERN Document Server

    Arnaldi, R; Barret, V; Bastid, N; Blanchard, G; Chiavassa, E; Cortese, P; Crochet, Philippe; Dellacasa, G; De Marco, N; Dupieux, P; Espagnon, B; Fargeix, J; Ferretti, A; Gallio, M; Lamoine, L; Luquin, Lionel; Manso, F; Mereu, P; Métivier, V; Musso, A; Oppedisano, C; Piccotti, A; Rahmani, A; Royer, L; Roig, O; Scalas, E; Scomparin, E; Vercellin, Ermanno

    1999-01-01

    Presentation made at RPC99 and submitted to Elsevier PreprintThe use of phenolic or melaminic bakelite as RPC electrodes is widespread. The electrode resistivity is an important parameter for the RPC performance. As recent studies have pointed out, the bakelite resistivity changes with temperature and is influenced by humidity. In order to gain a quantitative understanding on the influence of temperature and humidity on RPC electrodes, we assembled an apparatus to measure resistivity in well-controlled conditions. A detailed description of the experimental set-up as well as the first resistivity measurements for various laminates in different environmental conditions are presented.

  6. The bakelite for the RPCs of the experiment CMS

    OpenAIRE

    Altieri, S.; Bruno, Giacomo Luca

    2000-01-01

    Results from aging tests on the bakelite used for the CMS RPCs are presented. Samples of melaminic bakelite were exposed to a heavy gamma and neutron radiation. Data on the bulk resistivity were collected while accumulating gamma and neutron doses and particles fluence up to values well beyond those expected in 10 years of RPCs operation in the barrel region of CMS. The test with gamma radiation was performed at the CERN Gamma Irradiation Facility (GIF) with a 20 Ci 137Cs source. A total abso...

  7. Recycling Waste Bakelite As A Carbon Resource In Ironmaking

    OpenAIRE

    James Ransford Dankwah; Emmanuel Baawuah

    2015-01-01

    Abstract Bakelite is a 3-dimensional cross-linked network structured thermosetting polymer which is difficult to recycle after use. However it contains high levels of carbon and CaCO3 that can be recovered for use as reductant and fluxing agent in ironmaking. In this work we report the use of post-consumer bakelite as reductant for the production of metallic iron from iron oxide in a horizontal tube furnace through the composite pellet approach.Gas emission studies were conducted by pyrolysin...

  8. Study of Glass and Bakelite properties as electrodes in RPCs

    OpenAIRE

    Manisha,; Bhatnagar, V.; Shahi, J. S.

    2016-01-01

    India-based Neutrino Observatory (INO) collaboration is planning to build a magnetized Iron-CALorimeter detector (ICAL) for the study of atmospheric neutrinos. ICAL detector will be a stack of 151 layers of magnetized iron plates interleaved with Resistive Plate Chambers (RPCs) as active detector elements with a total mass of 50 kton. Resistive Plate Chambers are gaseous detectors made up of two parallel electrodes of high bulk resistivity like float glass and bakelite. These detectors are ex...

  9. Development of linseed oil-free bakelite resistive plate chambers

    CERN Document Server

    Biswas, S; Bose, S; Chattopadhyay, S; Saha, S; Viyogi, Y P

    2009-01-01

    In this paper we would like to present a few characteristics of the Resistive Plate Chambers (RPC) made of a particular grade of bakelite paper laminates (P-120, NEMA LI-1989 Grade XXX), produced and commercially available in India. This particular grade is used for high voltage insulation in humid conditions. The chambers are tested with cosmic rays in the streamer mode using argon, tetrafluroethane and isobutane in 34:59:7 mixing ratio. In the first set of detectors made with such grade, a thin coating of silicone fluid on the inner surfaces of the bakelite was found to be necessary for operation of the detector. Those silicone coated RPCs were found to give satisfactory performance with stable efficiency of >90% continuously for a long period as reported earlier. Results of the crosstalk measurement of these silicone coated RPC will be presented in this paper. Very recently RPCs made with the same grade of bakelite but having better surface finish, are found to give equivalent performance even without any ...

  10. Bakelite chambers for time-of-flight measurements

    CERN Document Server

    Cwiok, M; Górski, M; Królikowski, J

    1999-01-01

    We report on the search of composite organic materials with the volume resistivity ranging from 10 sup 8 to 10 sup 1 sup 1 OMEGA cm. Materials having resistivity in this range may be used for electrodes of thin gap Parallel Plate Avalanche Chambers. Gas detectors of such structure and operated at increased gas pressure allow, potentially, a sub-nanosecond time resolution. Using bakelite-like material with electrical properties well tuned during manufacturing opens the possibility to overcome limitations related to the semi-conductive glass employed usually for ultrafast gas detectors of parallel plate structure for time-of-flight technique.

  11. The bakelite for the RPCs of the experiment CMS

    Science.gov (United States)

    Altieri, S.; Belli, G.; Bruno, G.; Guida, R.; Merlo, M.; Ratti, S. P.; Riccardi, C.; Torre, P.; Vitulo, P.; Mognaschi, E. R.; Abbrescia, M.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.

    2000-12-01

    Results from aging tests on the bakelite used for the CMS RPCs are presented. Samples of melaminic bakelite were exposed to a heavy gamma and neutron radiation. Data on the bulk resistivity were collected while accumulating gamma and neutron doses and particles fluence up to values well beyond those expected in 10 years of RPCs operation in the barrel region of CMS. The test with gamma radiation was performed at the CERN Gamma Irradiation Facility (GIF) with a 20 Ci 137Cs source. A total absorbed dose of 5 Gy was accumulated during an irradiation period of about one month. The test with both neutron and gamma radiation was held at the Triga Mark II 250 kW reactor located in Pavia. A total of 80 h of exposure were accumulated integrating a neutron and gamma dose of about 80 Gy and a fast neutron fluence of some 10 11 cm-2. Experimental data on dose rate in both the test facilities have been compared to simulation output and show a good agreement.

  12. The bakelite for the RPCs of the experiment CMS

    CERN Document Server

    Altieri, S; Bruno, G; Guida, R; Merlo, M; Ratti, S P; Riccardi, C; Torre, P; Vitulo, P; Mognaschi, E R; Abbrescia, M; Colaleo, A; Iaselli, Giuseppe; Loddo, F; Maggi, M; Marangelli, B; Natali, S; Nuzzo, S; Pugliese, G; Ranieri, A; Romano, F

    2000-01-01

    Results from aging tests on the bakelite used for the CMS RPCs are presented. Samples of melaminic bakelite were exposed to a heavy gamma and neutron radiation. Data on the bulk resistivity were collected while accumulating gamma and neutron doses and particles fluence up to values well beyond those expected in 10 years of RPCs operation in the barrel region of CMS. The test with gamma radiation was performed at the CERN Gamma Irradiation Facility (GIF) with a 20 Ci /sup 137/Cs source. A total absorbed dose of 5 Gy was accumulated during an irradiation period of about one month. The test with both neutron and gamma radiation was held at the Triga Mark II 250 kW reactor located in Pavia. A total of 80 h of exposure were accumulated integrating a neutron and gamma dose of about 80 Gy and a fast neutron fluence of some 10/sup 11/ cm/sup -2/. Experimental data on dose rate in both the test facilities have been compared to simulation output and show a good agreement. (4 refs).

  13. Study of the molecular structure and dynamics of bakelite with neutron cross section measurements

    International Nuclear Information System (INIS)

    The molecular structure and dynamics of calcined bakelite were studied with neutron transmission and scattering cross section measurements. The total cross sections determined were correlated with data obtained with infra-red spectroscopy, elemental analysis and other techniques to get the probable molecular formulae of bakelite. The total cross section determined showed a deviation smaller than 5% from the literature values. The frequency distribution as well as overall experimental results allowed to suggest a structural model like polycyclic hydrocarbons for bakelite calcined at 8000 C. (F.E.). 65 refs, 31 figs, 5 tabs

  14. Molecular dynamical and structural studies for the bakelite by neutron cross section measurements

    International Nuclear Information System (INIS)

    Neutron reaction cross sections were determined by transmission and scattering measurements, to study the dynamics and molecular structure of calcined bakelites. Total cross sections were determined, with a deviation smaller than 5%, from the literature values, by neutron transmission method and a specially devised approximation. These cross sections were then correlated with data obtained with infra-red spectroscopy, elemental analysis and other techniques to get the probable molecular formulae of bakelite. Double differential scattering cross sections, scattering law values and frequency distributions were determined with 15% error using the neutron inelastic scattering method. The frequency distributions as well as the overall results from all experimental techniques used in this work allowed to suggest a structural model like polycyclic hydrocarbons, for calcined bakelite at 8000 C. (author)

  15. EFFECT OF BAKELITE INTERLAYER POWDER ON FRICTION STIR SPOT WELDING OF THERMOPLASTIC POLYMERS

    OpenAIRE

    Bekir ÇEVİK

    2014-01-01

    In this study, effect of bakelite interlayer powder on friction stir spot welding of polyethylene materials were investigated. 3 mm thick polyethylene materials were used in the experiments. 900 rpm rotational speed, 70, 100 and 130 seconds stirring time and 60 second waiting time were selected for the welding processes. Tensile-shear tests were applied on welded specimens and mechanical performances were determined

  16. Fabrication and Characterisation of Oil-Free Large Bakelite Resistive Plate Chamber

    CERN Document Server

    Ganai, Rajesh; Agarwal, Kshitij; Ahammed, Zubayer; Choudhury, Subikash; Chattopadhyay, Subhasis

    2015-01-01

    A large (240 cm $\\times$ 120 cm $\\times$ 0.2 cm) oil-free bakelite Resistive Plate Chamber (RPC) has been developed at VECC-Kolkata using locally available P-301 OLTC grade bakelite paper laminates. The chamber has been operated in streamer mode using Argon, Freon(R134a) and Iso-butane in a ratio of 34:57:9 by volume. The electrodes and glue samples were characterised by measuring their electrical parameters like bulk resistivity and surface resistivity. The performance of the chamber was studied by measuring the efficiency, time resolution and uniformity in detection of cosmic muons. The chamber showed an efficiency $>$95$\\%$ and time resolution ($\\sigma$) of $\\sim$0.83 ns. Details of the material characterisation, fabrication procedure and performance studies have been discussed.

  17. Temperature and humidity dependence of bulk resistivity of bakelite for resistive plate chambers in CMS

    International Nuclear Information System (INIS)

    This paper presents data obtained in a systematic study on the bulk resistivity of Korean bakelite as a function of temperature in the range 20-30 deg. C and relative humidity in the range 35-65%. Strong dependence of resistivity on both temperature and humidity was observed. Measurements were carried out in the framework of R and D work on Resistive Plate Chambers (RPCs) which will be used in the CMS detector

  18. Oxygen ion implantation induced microstructural changes and electrical conductivity in Bakelite RPC detector material

    Science.gov (United States)

    Kumar, K. V. Aneesh; Ranganathaiah, C.; Kumarswamy, G. N.; Ravikumar, H. B.

    2016-05-01

    In order to explore the structural modification induced electrical conductivity, samples of Bakelite Resistive Plate Chamber (RPC) detector materials were exposed to 100 keV Oxygen ion in the fluences of 1012, 1013, 1014 and 1015 ions/cm2. Ion implantation induced microstructural changes have been studied using Positron Annihilation Lifetime Spectroscopy (PALS) and X-Ray Diffraction (XRD) techniques. Positron lifetime parameters viz., o-Ps lifetime and its intensity shows the deposition of high energy interior track and chain scission leads to the formation of radicals, secondary ions and electrons at lower ion implantation fluences (1012 to1014 ions/cm2) followed by cross-linking at 1015 ions/cm2 fluence due to the radical reactions. The reduction in electrical conductivity of Bakelite detector material is correlated to the conducting pathways and cross-links in the polymer matrix. The appropriate implantation energy and fluence of Oxygen ion on polymer based Bakelite RPC detector material may reduce the leakage current, improves the efficiency, time resolution and thereby rectify the aging crisis of the RPC detectors.

  19. Study of RPC bakelite electrodes and detector performance for INO-ICAL

    CERN Document Server

    Kumar, Ashok; Hasbuddin, Md; Kumar, Praveen; Kumar, Purnendu; Kaur, Daljeet; Mishra, Swati; Naimuddin, Md

    2014-01-01

    The Resistive Plate Chambers (RPCs) are going to be used as the active detectors in the India-based Neutrino Observatory (INO)-Iron Calorimeter (ICAL) experiment for the detection and study of atmospheric neutrinos. In this paper, an extensive study of structural and electrical properties for different kind of bakelite RPC electrodes is presented. RPCs fabricated from these electrodes are tested for their detector efficiency and noise rate. The study concludes with the variation of efficiency, leakage current and counting rate over the period of operation with different gas compositions and operational conditions like temperature and relative humidity.

  20. Long Term Performance Studies of Large Oil-Free Bakelite Resistive Plate Chamber

    CERN Document Server

    Ganai, Rajesh; Shiroya, Mehul Kumar; Agarwal, Kshitij; Ahammed, Zubayer; Choudhury, Subikash; Chattopadhyay, Subhasis

    2016-01-01

    Several high energy physics and neutrino physics experiments worldwide require large-size RPCs to cover wide acceptances. The muon tracking systems in the Iron calorimeter (ICAL) in the INO experiment, India and the near detector in DUNE at Fermilab are two such examples. A (240 cm $\\times$ 120 cm $\\times$ 0.2 cm) bakelite RPC has been built and tested at Variable Energy Cyclotron Centre, Kolkata, using indigenous materials procured from the local market. No additional lubricant, like oil has been used on the electrode surfaces for smoothening. The chamber is in operation for $>$ 365 days. We have tested the chamber for its long term operation. The leakage current, bulk resistivity, efficiency, noise rate and time resolution of the chamber have been found to be quite stable during the testing peroid. It showed an efficiency $>$ 95$\\%$ with an average time resolution of $\\sim$0.83 ns at the point of measurement at 9000 V throughout the testing period. Details of the long term performance of the chamber have be...

  1. Investigation of mass attenuation coefficients of water, concrete and bakelite at different energies using the FLUKA Monte Carlo code

    International Nuclear Information System (INIS)

    The mass attenuation coefficients of water, bakelite and concrete sample defined in the simulation package were obtained using the FLUKA Monte Carlo code at 59.5, 80.9, 140.5, 356.5, 661.6, 1173.2 and 1332.5 keV photon energies. The results for the mass attenuation coefficients obtained by simulation have been compared with experimental and the theoretical ones and good agreement has been observed. The results indicate that this process can be followed to determine the data on the attenuation of gamma-rays with the several energies in other materials. Also, the deposited energy by 661.6 keV photons at several thicknesses of each media was determined as being an important data for radiation shielding studies. (author)

  2. Temperature and humidity dependence of bulk resistivity of bakelite for resistive plate chambers in CMS

    CERN Document Server

    Ahn, S H; Bahk, S Y; Gapienko, V A; Hong, B; Hong, S J; Jung, S Y; Kim, J Y; Kim, Y J; Kim, Y U; Koo, D G; Lee, K S; Lee, S J; Lee, Y L; Lim, I T; Nam, S K; Pac, M Y; Park, S K; Ra, Y S; Rhee, J T; Seo, S W; Sim, K S

    2000-01-01

    This paper presents data obtained in a systematic study on the bulk resistivity of Korean bakelike as a function of temperature in the range 20-30 degrees C and relative humidity in the range 35-65%. Strong dependence of resistivity on both temperature and humidity was observed. Measurements were carried out in the framework of R&D work on resistive plate chambers which will be used in the CMS detector. (4 refs).

  3. TERMOPLASTİK POLİMERLERİN SÜRTÜNME KARIŞTIRMA NOKTA KAYNAĞINA BAKALİT ARA TABAKA TOZUNUN ETKİSİ

    OpenAIRE

    Bekir ÇEVİK

    2014-01-01

    In this study, effect of bakelite interlayer powder on friction stir spot welding of polyethylene materials were investigated. 3 mm thick polyethylene materials were used in the experiments. 900 rpm rotational speed, 70, 100 and 130 seconds stirring time and 60 second waiting time were selected for the welding processes. Tensile-shear tests were applied on welded specimens and mechanical performances were determined.

  4. A modified method for the synthesis of polycondensate phenolic resin with iminodiacetic caid (IDA) functional group for treatment of alkaline waste from reprocessing plants (Preprint no. SST-10)

    International Nuclear Information System (INIS)

    Synthesis of bakelite type resin with iminodiacetic acid(IDA) group was carried out. The product formed by following the procedure published in literature was found to be unstable in alkaline solution and the reaction rate was considerably slow. A modified method for preparing the resin with improved stability is discussed in this paper. (author). 2 refs., 2 tab

  5. Effect of neutron irradiation on vitreous carbon

    International Nuclear Information System (INIS)

    The change in mass (m), volume (V), specific electric resistance (ρ), coefficient of linear thermal expansion (α), dynamic elasticity modulus (E), and limit of bending strength (σ) of vitreous carbon are studied upon neutron irradiation. Samples for study were two forms of vitreous carbon obtained by hardening thermally reactive polymers at 900-1,000 degree K. Phenol-formaldehyde (bakelite lacquer A, Bakelite A) and furfural-phenol-formaldehyde (FM-2) resin were used. They were irradiated in the experimental water - water VVR-M reactor between 360-1,030 degree K. The maximal neutron flux was 1.65·1021 neut/cm2. Neutron irradiation of vitreous carbon led to its shrinkage and accompanied weakening. Shrinkage and weakening of vitreous carbon was decreased with an increase of treatment and irradiation temperatures

  6. TERMOPLASTİK POLİMERLERİN SÜRTÜNME KARIŞTIRMA NOKTA KAYNAĞINA BAKALİT ARA TABAKA TOZUNUN ETKİSİ

    Directory of Open Access Journals (Sweden)

    Bekir ÇEVİK

    2014-05-01

    Full Text Available In this study, effect of bakelite interlayer powder on friction stir spot welding of polyethylene materials were investigated. 3 mm thick polyethylene materials were used in the experiments. 900 rpm rotational speed, 70, 100 and 130 seconds stirring time and 60 second waiting time were selected for the welding processes. Tensile-shear tests were applied on welded specimens and mechanical performances were determined.

  7. Characterization of opaques off Konkan Coast Maharashtra, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gujar, A.R.; Angusamy, N.; Rajamanickam, G. V.

    pigments. TiO2 pigment is mainly used in the Paints & Coatings (59 %), Plastics (20 %) and Paper (13 %) industries [2]. Trends such as use of bright glossy finishes in paints, higher demand for light paper, increased paper recycling, and substitution... Philips PWG. 1840 Powder diffractometer. Representative detrital ilmenites (8 Nos) and magnetites ( 8 Nos), covering the bays, were mounted on a bakelite medium and after polishing, under reflected light, examined for their nature of intergrowths...

  8. Large drift tube arrays with external delay line readout

    International Nuclear Information System (INIS)

    The construction and performance of 2 meter long, 5 cm diameter, circular drift tubes made of 1 mm thick bakelite paper coated inside with conductive paint. The longitudinal coordinate is read-out with an external delay line system. The measured spatial resolution obtained from the drift time is close to 180 μm (one standard deviation). A system of 1100 tubes has been built for a muon experiment

  9. Microhardness and relaxation properties of carbon glass

    International Nuclear Information System (INIS)

    Changes of microhardness of carbon glass (CG) made from cast (FM-2) and granulated (Bakelit A) thermosetting resins treated at 1100-3100 K are studied after thermal treatment and neutron irradiation. It is shown that CG microhardness change kinetics during ageing after certain treatment is caused by stress changes in nearsurface layers of samples and is dependent on peculiarities of supermolecular structural organization of CG

  10. Optimisation and Characterisation of Glass RPC for India-based Neutrino Observatory Detectors

    OpenAIRE

    Kanishka, R.; Bhatnagar, Vipin; Indumathi, D.

    2016-01-01

    The proposed magnetised Iron CALorimeter detector (ICAL) to be built in the India-based Neutrino Observatory (INO) laboratory aims to detect atmospheric muon neutrinos. In order to achieve improved physics results, the constituent components of the detector must be fully understood by proper characterisation and optimisation of various parameters. Resistive Plate Chambers (RPCs) are the active detector elements in the ICAL detector and can be made of glass or bakelite. The number of RPCs requ...

  11. A theoretical way to determine gamma-ray mass attenuation coefficients of materials

    OpenAIRE

    ERMİŞ, ELİF EBRU; PİLİÇER, Ercan; ÇELİKTAŞ, CÜNEYT

    2015-01-01

    The gamma-ray mass attenuation coefficients of various absorber materials such as Ag, Al, Au, Bakelite, Cu, Fe, Pb, Plexiglas, Si, Sn, water, and Zn were determined theoretically at different gamma-ray energies and different absorber thicknesses in order to investigate how the number of gamma photons and their energies affect the calculation of mass attenuation coefficients of the absorbers since no study such a comprehensive work here was encountered. For this purpose, the FLUKA ...

  12. Performances of RPC detectors with tracking and timing electronics

    International Nuclear Information System (INIS)

    The bakelite Resistive Plate Counters (RPC) for the COVER-PLASTEX experiment have been tested with special tracking and timing electronics developed by the T and T collaboration for use as a front-end electronics able to give position and arrival time for each particle in the EAS front crossing the detector. Results on single counting rate, efficiency, time resolution, signal shape and after pulse presence are given as a function of the high voltage and input signal threshold. (orig.)

  13. A low-resistivity RPC for the ALICE dimuon arm

    International Nuclear Information System (INIS)

    In view of ALICE, the dedicated Heavy-Ion Experiment at LHC, a Resistive Plate Chamber (RPC) with electrodes made of low-resistivity bakelite (ρ≅3.5x109 Ω cm) has been tested at the CERN SPS both in streamer and in avalanche mode. The chamber has shown a stable behaviour and excellent rate capability: its efficiency is better than 95% for local particle fluxes of about 1 and 10 kHz/cm2 for operation in streamer and in avalanche mode, respectively. The cluster size and the time resolution have also been measured for both modes of operation

  14. Tests on OPERA RPCs

    International Nuclear Information System (INIS)

    OPERA is an experiment for the observation of νμ into ντ oscillations through τ appearance using a 730 km baseline νμ beam from CERN to Gran Sasso underground laboratory. The magnet yokes of the two muon spectrometers are instrumented with high resistivity bakelite RPCs operated in streamer mode. The RPC installation ended in March 2005. As the detectors will be inaccessible during the operation, we performed long term operation as well as quality control tests. The results of the long term and of the Quality Control tests are presented

  15. Tests on OPERA RPCs

    Energy Technology Data Exchange (ETDEWEB)

    Bergnoli, A.; Borsato, E.; Brugnera, R. [Padova University and INFN, Padova (Italy); Buccheri, E. [Universita ' La Sapienza' and INFN, Rome (Italy); Candela, A. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Carrara, E.; Ciesielski, R. [Padova University and INFN, Padova (Italy); Corradi, G. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); D' Incecco, M. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Dal Corso, F. [Padova University and INFN, Padova (Italy); Degli Esposti, L. [Bologna University and INFN, Bologna (Italy); Di Giovanni, A.; Di Marco, N. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Di Troia, C. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Dusini, S.; Fanin, C. [Padova University and INFN, Padova (Italy); Felici, G.; Gambarara, A. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Garfagnini, A. [Padova University and INFN, Padova (Italy); Grianti, F. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Gustavino, C.; Lindozzi, M. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Longhin, A. [Padova University and INFN, Padova (Italy); Mastropietro, F.; Mengucci, A. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Monacelli, P. [L' Aquila University and INFN, l' Aquila (Italy); Paoloni, A. [INFN Laboratori Nazionali di Frascati, Frascati (Italy)]. E-mail: alessandro.paoloni@lnf.infn.it; Stanco, L. [Padova University and INFN, Padova (Italy); Tatananni, E. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Terranova, F.; Spinetti, M. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Stipcevic, M. [Rudjer Boskovic Institute (IRB), Zagreb (Croatia); Terminiello, L.; Ventura, M.; Votano, L. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Zauner, B

    2006-08-15

    OPERA is an experiment for the observation of {nu}{sub {mu}} into {nu}{sub {tau}} oscillations through {tau} appearance using a 730 km baseline {nu}{sub {mu}} beam from CERN to Gran Sasso underground laboratory. The magnet yokes of the two muon spectrometers are instrumented with high resistivity bakelite RPCs operated in streamer mode. The RPC installation ended in March 2005. As the detectors will be inaccessible during the operation, we performed long term operation as well as quality control tests. The results of the long term and of the Quality Control tests are presented.

  16. Determination of scatter fractions of some materials by experimental studies and Monte Carlo calculations

    CERN Document Server

    Meric, N; Bor, D

    1999-01-01

    Scatter fractions have been determined experimentally for lucite, polyethylene, polypropylene, aluminium and copper of varying thicknesses using a polyenergetic broad X-ray beam of 67 kVp. Simulation of the experiment has been carried out by the Monte Carlo technique under the same input conditions. Comparison of the measured and predicted data with each other and with the previously reported values has been given. The Monte Carlo calculations have also been carried out for water, bakelite and bone to examine the dependence of scatter fraction on the density of the scatterer.

  17. The trigger of the ALICE dimuon arm architecture and detectors

    CERN Document Server

    Arnaldi, R; Barret, V; Bastid, N; Blanchard, G; Chiavassa, E; Cortese, P; Crochet, Philippe; Dellacasa, G; De Marco, N; Dupieux, P; Espagnon, B; Fargeix, J; Gallio, M; Lamoine, L; Luquin, Lionel; Manso, F; Métivier, V; Musso, A; Piccotti, A; Rahmani, A; Ramillien, V; Royer, L; Roig, O; Scalas, E; Scomparin, E; Vercellin, Ermanno

    1999-01-01

    The trigger system of the ALICE dimuon arm is based on resistive plate chambers (RPC). Besides a short description of the trigger system, the test results of a RPC prototype with electrodes made of low resistivity bakelite ( equivalent to 3.10/sup 9/ Omega .cm) are presented. Rate capability, time resolution and cluster size have been measured for the RPC operated both in streamer and in avalanche mode. Although the rate capability is obviously higher in avalanche mode (few kHz/cm/sup 2/), remarkable results have been achieved even in streamer mode (several hundreds of Hz/cm/sup 2/). (6 refs).

  18. Organic Fingerprint Powders Based on Fluorescent Phloxine B Dye.

    Directory of Open Access Journals (Sweden)

    G. S. Sodhi

    2000-04-01

    Full Text Available Novel fingerpript powders based on organic dye (phJoxine B have been prepared using insoluble salts as adhesive matrials in place of costly resinous polymers (which most conventional powders incorporate. Sharp and clear prints have been developed on a wide range of surfaces, such as paper, I plastic, glass, bakelite, enamelled metal and polished wood. The fluorescent nature of phloxine B assists in developing weak prints und.er ultraviolet light which can assist a forensic scientist for lifting  fingerprints frqm the scene of crime and also a defence scientist for establishing the identity of deceased native soldiers as well as of prisoners of war.

  19. Development of Multi-gap Resistive Plate Chamber (MRPC) for medical imaging

    CERN Document Server

    Banerjee, A; Biswas, S; Chattopadhyay, S; Das, G; Pal, S

    2014-01-01

    The low cost and high resolution Multi-gap Resistive Plate Chamber (MRPC) opens up a new possibility to find an efficient alternative detector for the Time of Flight (TOF) based Positron Emission Tomography, where the sensitivity of the system depends largely on the time resolution of the detector. In a layered structure, suitable converters can be used to increase the photon detection efficiency. In this paper results of the cosmic ray test of a four-gap bakelite-based prototype MRPC operated in streamer mode and six-gap glass-based MRPC operated in avalanche mode are discussed.

  20. Neutron cross section measurements for graphites and polymers

    International Nuclear Information System (INIS)

    Total neutron cross sections at 0,05 eV were determined for national, american, japanese and french graphites with the neutron crystal spectrometer installed at the Argonaut reactor of the IEN-CNEN-RJ. It is defined a boron equivalent for each graphite sample. In order that the dynamics and structural properties of calcined Bakelites could be determined, neutron frequency spectra and scattering laws were measured with the neutron time-of-flight and beryllium arrangement at IEA-R1 reactor of the IPEN-CNEN-SP. (author)

  1. 1. Airborne 2. Hangár

    OpenAIRE

    Johnson, Christy

    2008-01-01

    Hangár, Bakelit Multi Art Center 7th L1 Dance Festival, Budapest, Hungary Installation, 2008 AIRBORNE (projection-sound-monitor installation) was sited in the Hangár, B.A.C. as part of the 7th L1 Dance Festival in Budapest, Hungary (March 2008). This work continues Johnson's interest in and use of 'found' material (16mm wind tunnel footage), and performative methods (sound recording of Channel 9 on United Airlines). This immersive work explores the turbulence of suspension and sets ...

  2. Highly efficient resistive plate chambers for high rate environment

    International Nuclear Information System (INIS)

    The full scale prototype of an Inverted Double Gap RPC module for ME-1/1 station of the CMS detector was tested in the Gamma Irradiation Facility at the CERN SPS muon beam. The chamber made of medium resistivity bakelite and filled with 'green gas' mixture of C2H2F4/iso-butane/SF6 has wide efficiency plateau and good timing properties when operated in avalanche mode under continuous irradiation with strong 137Cs source for rates up to about 5 kHz/cm2/gap

  3. Development and characterization of single gap glass RPC

    CERN Document Server

    Manisha,; Shahi, J S; Singh, J B

    2016-01-01

    The India-based Neutrino Observatory (INO) collaboration is going to build a 50 kton magnetized Iron CALorimeter (ICAL) detector for the precise measurement of neutrino oscillations using atmospheric neutrinos. The proposed ICAL detector will be a stack of magnetized iron plates (acting as target material) interleaved with the glass Resistive Plate Chambers (RPCs)as active elements. RPC is a gaseous detector made up of two parallel electrodes having high bulk resistivity like that of the float glass and bakelite. For ICAL detector, glass is preferred over bakelite as it does not need any kind of surface treatment to achieve better surface uniformity and also the cost of detector is reduced. Under detector R&D efforts for the proposed detector, we have fabricated the glass RPCs of 1m X 1m in size procuring glass of ~ 2 mm thickness from one of the Indian glass manufacturers (Asahi). In the present characterization studies, we report on the leakage current, pulse width optimization for the measurements of e...

  4. An Improved Technique for the Preparation of Mounted or Unmounted Carbon/Epoxy Specimens

    Science.gov (United States)

    Edahl, Robert A., Jr.

    2007-01-01

    As carbon/epoxy materials became more prevalent in the aerospace industry, microstructural analysis demanded specimen preparation techniques that led to better polished surfaces, achievable in a shorter time, and using fewer steps. The desire to use image analysis for material characterization also helped drive the goal for defect free surfaces. At NASA-Langley (LaRC), carbon/epoxy specimens had been historically prepared in 1 inch diameter Bakelite mounts. Carbon/epoxy specimens that were 1/8 to 1/4 inch thick were not affected by the heat and pressure required for mounting in Bakelite, however thinner specimens were crushed during mounting. A two-part room temperature curing epoxy was chosen as an alternative but sometimes voids developed between the specimen and the mounting material. This was prevented by either heating the epoxy to 140 degrees F to lower the viscosity of the epoxy or by using a vacuum impregnation apparatus. Both techniques helped facilitate flow and allowed the epoxy to penetrate crevices.

  5. A new type of RPC for the VETO of JUNO

    Science.gov (United States)

    Xie, B.; Wang, Y.; Guo, B.; Zhu, W.; Li, Y.; Cheng, J.

    2014-10-01

    The capability of covering very large areas at low cost, besides showing excellent performance in many aspects, motivated the application of RPCs to Neutrino physics research in experiments such as Daya Bay neutrino experiment. However, some of the traditional bakelite RPCs cannot work well in these hash underground environments. This paper mainly describes a new type of RPC for the VETO detector of JUNO. It is developed with thin float glass, and a special necklace spacer is designed to keep the gap uniformity. The RPC is sealed in a gas tight box, so it will not be affected directly by ambient environment and it can work well in humid condition underground. A one-dimensional and a two-dimensional readout RPC prototypes have been developed and tested in our lab. The results show that the detection efficiency can reach as high as 98% and the noise rate is less than 1 Hz/cm2 both in the avalanche mode and streamer mode. The dark current is much lower than the traditional Bakelite RPC. Some details of the structure and performance of the new type of RPC are all described in this paper.

  6. Beam test results of CMS RPCs at high eta region under high-radiation environment

    CERN Document Server

    Park, S; Bahk, S Y; Hong, B; Hong, S J; Kang, D H; Kang, T I; Kim, T J; Kim, Y J; Kim, Y U; Koo, D G; Lee, H W; Lee, K S; Lee, S J; Lim, J K; Moon, D H; Nam, S K; Oh, J K; Park, W J; Rhee, J T; Ryu, M S; Shim, H H; Sim, K S

    2004-01-01

    The Compact Muon Solenoid (CMS) forward resistivity plate chambers (RPCs) at the high eta region must be operated in presence of a radiation-induced rate as high as 1 kHz/cm**2. It is still unknown if the RPCs coated with linseed oil can be operated under such a high- radiation environment over the lifetime of CMS. Non-oiled RPCs may be one of the options since phenolic or melamine-coated bakelite is chemically stabler than linseed oil. We have constructed oiled and non-oiled RPCs at the high eta region of CMS using phenolic bakelite and tested them in the Gamma Irradiation Facility at CERN. While both RPCs show the same characteristics in the efficiency and the strip multiplicity, the non-oiled RPC generates an intrinsic noise rate of 50 Hz/cm**2, compared to only 5 Hz/cm**2 for the oiled RPC, both at 10.0kV which is about 100 V above the 95% knee of the efficiency curve.

  7. A new type of RPC for the VETO of JUNO

    International Nuclear Information System (INIS)

    The capability of covering very large areas at low cost, besides showing excellent performance in many aspects, motivated the application of RPCs to Neutrino physics research in experiments such as Daya Bay neutrino experiment. However, some of the traditional bakelite RPCs cannot work well in these hash underground environments. This paper mainly describes a new type of RPC for the VETO detector of JUNO. It is developed with thin float glass, and a special necklace spacer is designed to keep the gap uniformity. The RPC is sealed in a gas tight box, so it will not be affected directly by ambient environment and it can work well in humid condition underground. A one-dimensional and a two-dimensional readout RPC prototypes have been developed and tested in our lab. The results show that the detection efficiency can reach as high as 98% and the noise rate is less than 1 Hz/cm2 both in the avalanche mode and streamer mode. The dark current is much lower than the traditional Bakelite RPC. Some details of the structure and performance of the new type of RPC are all described in this paper

  8. Radiation doses from dental radiography at private practioneers

    International Nuclear Information System (INIS)

    This investigation was made in January 1975 together with a seminar group from the faculty of odontology in Stockholm. Every four private practising dentists in Stockholm and its environs were selected by haphazard to get an enquiry equipment etc. Every forty private practising dentists were then selected by haphazard to get a visit. 32 x-ray plants were investigated. The radiation doses showed a great spreading. The mean value of the radiation doses to the irradiated organs had been reduced about 5 times compared to a similar investigation, which was made in 1960. The use of long metal tubes and high-speed film gave the lowest dose values, while a short cone of bakelite and a low-speed film gave the highest dose values. Fluctuations in the dose values seemed also to depend on the technique. The reasons for this may be variations in the settings of the instruments and in the dark room technique. (M.S.)

  9. Optimisation and Characterisation of Glass RPC for India-based Neutrino Observatory Detectors

    CERN Document Server

    Kanishka, R; Indumathi, D

    2016-01-01

    The proposed magnetised Iron CALorimeter detector (ICAL) to be built in the India-based Neutrino Observatory (INO) laboratory aims to detect atmospheric muon neutrinos. In order to achieve improved physics results, the constituent components of the detector must be fully understood by proper characterisation and optimisation of various parameters. Resistive Plate Chambers (RPCs) are the active detector elements in the ICAL detector and can be made of glass or bakelite. The number of RPCs required for this detector is very large number so a detailed R & D is necessary to establish the characterisation and optimisation of these RPCs. These detectors once installed will be taking data for 15-20 years. In this paper, we report the selection criteria of glass used of various Indian manufacturers such as Asahi, Saint Gobain and Modi. Based on the factors like aging that deteriorate the quality of glass the choice is made. The glass characterisation studies include UV-VIS transmission for optical properties, SEM...

  10. Laser beam characterization of the ATLAS RPC gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Chiodini, G. [INFN Lecce, via per Arnesano, 73100 Lecce (Italy); Coluccia, M.R.; Gorini, E. [INFN Lecce, via per Arnesano, 73100 Lecce (Italy); Dipartimento di Fisica, Universita degli Studi di Lecce, via per Arnesano, 73100 Lecce (Italy); Grancagnolo, F.; Primavera, M. [INFN Lecce, via per Arnesano, 73100 Lecce (Italy)

    2007-10-15

    A measurement of the electrons drift velocity in C{sub 2}H{sub 2}F{sub 4}-based gas mixture has been performed and results have been compared with calculations. Primary ionization is induced in the gas via double photon ionization process by mean of a pulsed Nitrogen laser. The results of the drift velocity, obtained at room temperature and normal pressure, are presented as a function of the electric field strength. To perform the measurements we used a small sized RPC prototype with a 2 mm gas gap delimited by 2mm-thick linseed-oil-treated bakelite plates with resistivity of about 1.71x10{sup 10}{omega} cm at 20{sup o}C.

  11. Laser beam characterization of the ATLAS RPC gas mixture

    International Nuclear Information System (INIS)

    A measurement of the electrons drift velocity in C2H2F4-based gas mixture has been performed and results have been compared with calculations. Primary ionization is induced in the gas via double photon ionization process by mean of a pulsed Nitrogen laser. The results of the drift velocity, obtained at room temperature and normal pressure, are presented as a function of the electric field strength. To perform the measurements we used a small sized RPC prototype with a 2 mm gas gap delimited by 2mm-thick linseed-oil-treated bakelite plates with resistivity of about 1.71x1010Ω cm at 20oC

  12. Upgrade to the front-end electronics of the BESIII muon identification system

    International Nuclear Information System (INIS)

    Resistive Plate Chambers (RPCs) built from a new type of Bakelite developed at Institute of High Energy Physics (IHEP), Chinese Academy of Sciences have been used in the BESIII Muon identification system for several years without linseed oil coating, but characteristic aging performances were observed. To adapt to the RPCs in the aging state, the front-end electronics have been upgraded by enhancing the front-end protection, improving the threshold setting circuit, and separating power supplies of the comparator and the field programmable gate array (FPGA). Improvements in system stability, front-end protection and threshold consistency have been achieved. In this paper, the system upgrade and the test results are described in detail. (authors)

  13. Effect of sample thickness on the measured mass attenuation coefficients of some compounds and elements for 59.54, 661.6 and 1332.5 keV gamma-rays

    CERN Document Server

    El-Rahman, M A; Abdel-Hady, Y L; Kamel, N

    2000-01-01

    Measurements have been made to determine gamma-rays attenuation coefficients very accurately by using an extremely narrow-collimated-beam transmission method. The effect of the sample thickness on the measured values of the mass attenuation coefficients (mu/rho) cm sup 2 /g of perspex, bakelite, paraffin, Al, Cu, Pb and Hg have been investigated at three different gamma-ray energies (59.54, 661.6 and 1332.5 keV). It is seen that for these chosen materials (mu/rho) remains constant in good agreement with the theoretical values up to 3 mean free paths and after that (mu/rho) values for Cu, Pb and Hg decrease with further increase in the absorber thickness. This result may be attributed to the increase in the number of coherent small-angle scattering photons which reach the detector.

  14. Study of the impact of environmental parameters on the operation of CMS RPCs

    CERN Document Server

    Assran, Yasser

    2011-01-01

    CMS (Compact Muon Solenoid) is a general purpose detector designed to run at the highest luminosity at Large Hadron Collider (LHC), CERN, Geneva, Switzerland. The muon system of the CMS experiment relies on Drift Tubes (DT), Cathode Strip Chambers (CSC) and Resistive Plate Chambers (RPC). RPCs are dedicated for the first level muon trigger and they are characterized by bakelite electrodes delimited in a specialized gas volume filled with operational gas mixture. This analysis has been done for the RPC chambers installed in CMS experiment at CERN. The Currents of CMS RPCs chambers are analyzed as a function of environmental parameters such as Temperature, Humidity and pressure, which are important for the operation of the muon detector system. A novel Neural Network approach has been used to analyze the data and to build a model using experimental measurements and combining the results of the simulations. Data from RPC Chambers in CMS experiment are taken and compared to the results from neural Network.

  15. Beam test results of the first full-scale prototype of CMS RE 1/2 Resistive Plate Chamber

    CERN Document Server

    Ying, Jun; Cai Jian Xin; Liu Hong Tao; Qian Si Jin; Wang Quan Jin; Ye Yan Lin

    2005-01-01

    We reported the muon beam test results of the first full-scale prototype of CMS RE 1/2 Resistive Plate Chamber (RPC). The bakelite surface is treated using a special technology without oil to make it smooth enough. The full scale RE 1/2 RPC with honeycomb supporting frame is strong and thin enough to be fitted to the limited space of CMS design for the inner Forward RPC. The muon beam test was performed at CERN Gamma Irradiation Facility (GIF). The detection efficiency of this full scale RPC prototype is >95% even at very high irradiation background. The time resolution (less than 1.2 ns) and spatial resolution are satisfactory for the muon trigger device in future CMS experiments. The noise rate is also calculated and discussed.

  16. Test of large area glass RPCs at the DAΦNE Test Beam Facility (BTF)

    International Nuclear Information System (INIS)

    The CaPiRe program has been started to develop a new detector design, in order to produce large areas of glass Resistive Plate Chambers (RPC) detectors, overcoming the previous limitations. As a first step we produced our glass RPC detectors (1m2) at General Tecnica exploiting their standard procedures, materials and production techniques simply using 2 mm glass electrodes instead of the bakelite ones. A set of RPC was produced by using pre-coated (silk screen printed) electrodes, while others were produced with the standard graphite coating. All the detectors, together with four old Glass RPC acting as reference, were tested at the DAΦNE Test Beam Facility with 500MeV electrons in order to study the efficiency in different positions inside the detectors (i.e. near spacers and edges) and to study the detector behavior as a function of the local particle rate

  17. The BaBar instrumented flux return performance: lessons learned

    CERN Document Server

    Anulli, F; Baldini, R; Band, H R; Bionta, R; Brau, J E; Brigljevic, V; Buzzo, A; Calcaterra, A; Carpinelli, M; Cartaro, C; Cavallo, N; Crosetti, G; De Nardo, Gallieno; De Sangro, R; Eichenbaum, A; Fabozzi, F; Falciai, D; Ferrarotto, F; Ferroni, F; Finocchiaro, G; Forti, F; Frey, R; Gatto, C; Graug; Iakovlev, N I; Iwasaki, M; Johnson, J R; Lange, D J; Lista, L; Lo Vetere, M; Lü, C; Macri, M; Messner, R; Moore, T B; Morganti, S; Neal, H; Neri, N; Palano, A; Paoloni, E; Paolucci, P; Passaggio, S; Pastore, F C; Patteri, P; Peruzzi, I; Piccolo, D; Piccolo, M; Piredda, G; Robutti, E; Roodman, A; Santroni, A; Sciacca, C; Sinev, N B; Soha, A; Strom, D; Tosi, S; Vavra, J; Wisniewski, W J; Wright, D M; Xie, Y; Zallo, A

    2002-01-01

    The BaBar Collaboration has operated an instrumented flux return (IFR) system covering over 2000 m sup 2 with resistive plate chambers (RPCs) for nearly 3 years. The chambers are constructed of bakelite sheets separated by 2 mm. The inner surfaces are coated with linseed oil. This system provides muon and neutral hadron detection for BaBar. Installation and commissioning were completed in 1998, and operation began mid-year 1999. While initial performance of the system reached design, over time, a significant fraction of the RPCs demonstrated significant degradation, marked by increased currents and reduced efficiency. A coordinated effort of investigations have identified many of the elements responsible for the degradation. This article presents our current understanding of the aging process of the BaBar RPCs along with the action plan to combat performance degradation of the IFR system.

  18. The Monitor online system of the OPERA muon magnetic spectrometer

    CERN Document Server

    Ugolino, U.; Acquafredda, R.; Masone, v.

    2008-01-01

    The OPERA muon magnetic spectrometer has been designed for muon detection, tracking and timing. The 44 bakelite Resistive Chambers (RPC) planes, imbibed inside the magnet iron slabs, must provide the tracking of the muon curved in the magnetic field to ease the momentum and charge measurement provided by the HPT. Furthermore, it provides the momentum for muons stopping in the iron. RPC signals will be also used as start of drift tube acquisition thanks to the very good time resolution of RPC detectors. Due to the required performances the tracking detector must be fully efficient and stable. In this conditions an online monitor is mandatory to continuously control stability of run conditions. We report the main characteristics and performances of the monitor system for the OPERA spectrometer and capabilities of the software developed for settings and data acquisition.

  19. Long-term operation test of RPCs for the OPERA experiment

    International Nuclear Information System (INIS)

    OPERA is one of the two detectors foreseen in the CERN Neutrino to Gran Sasso project, devoted to the detection of νμ into ντ oscillations in the parameter region suggested by SuperKamiokande data on atmospheric neutrinos. Bakelite RPCs will be used to instrument the iron yoke of the muon spectrometers. We present the results of long-term (greater than 6 months) streamer operations of real size OPERA RPCs at cosmic rays fluxes. Given the very low rate observed in the underground Gran Sasso Laboratories, under 3km w.e., even this short time period is equivalent to more than 10 OPERA years. Results of tests with different gas mixtures are reported, in view of decreasing the streamer charge of operation for the RPCs employed in the experiment

  20. Method of measuring dielectric constant using an oscilloscope

    Science.gov (United States)

    Nogi, Yasuyuki; Watanabe, Masayuki; Suzuki, Kiyomitsu; Ohkuma, Yasunori

    2015-09-01

    A simple relationship determining the dielectric constant of a material inserted in a parallel-plate capacitor is formulated from Gauss's law for a uniform electric field and the continuity condition of electric flux at the boundary of the material. The relationship suggests that the dielectric constant can be determined from the dependence of the charge stored on the capacitor on the thicknesses of the material and the air layer between the plates. A uniform field is created by applying an ac voltage to the plates, which includes a guard ring. The stored charge is estimated by using an oscilloscope to measure the voltage across a resistor inserted between the power supply and the capacitor. The results of the measurement are given for planar materials such as soda-lime glass, Bakelite, acrylic glass, and Teflon with a thickness of 0.5-1 cm.

  1. Study of cosmic ray muons tracks recorded by prototype ICAL (Kolkata): Zenith angle distribution

    International Nuclear Information System (INIS)

    The India-based Neutrino Observatory (INO) collaboration is moving fast towards setting up a magnetized Iron CALorimeter (ICAL) to study atmospheric neutrinos and to determine the neutrino oscillation parameters with high precision. In final phase ICAL uses 50 kton Iron as target mass and ∼ 30000 glass Resistive Plate Chambers (RPC) having dimension 2m x 2m x 0.002m and 4m x 2m x 0.002m as active detector elements. A prototype RPC detector stack comprising 12 layers of RPCs of glass and bakelite having area 1m x 1m is in continuous operation with and without magnetic field having strength 1.5 Tesla for the last two years. We present here the recent results of the studies performed with this experimental set up

  2. Use of RPC in EAS physics with the COVER-PLASTEX experiment

    International Nuclear Information System (INIS)

    Bakelite resistive plate counters (RPCs) have been used for the first time in extensive air shower (EAS) physics with the COVER-PLASTEX experiment in Haverah Park, near Leeds, UK for a detailed investigation of the space-time structure of the shower front. For this purpose new front-end electronics have been developed, and an accurate investigation on the RPC performances and pick-up characteristics has been performed. Measurements of the noise, cross talk, after-pulses and detector saturation have permitted to understand the behaviour of this detector in operational conditions. A direct comparison with scintillators of the GREX array demonstrates the capability of the RPC to measure the lateral distribution of shower particles and emphasizes the advantage of this detector for a detailed analysis of EAS front characteristics. (orig.)

  3. Performance and simulation of a double-gap resistive plate chamber in the avalanche mode

    CERN Document Server

    Ahn Sung Hwan; Hong Byung Sik; Hong Seong Jong; Ito, M; Kang, T I; Kim, B I; Kim, J H; Kim, Y J; Kim, Y U; Koo, D G; Lee Hyup Woo; Lee, K B; Lee Kyong Sei; Lee Seok Jae; Lim, J K; Moon, D H; Nam, S K; Park, S; Park, W J; Rhee June Tak; Ryu, M S; Sim Kwang Souk

    2004-01-01

    We present a detailed analysis of the time and the charge signals of a prototype double-gap resistive plate chamber for the endcap region of the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC). The chamber was built with relatively low-resistivity bakelite. The time and the charge results demonstrate that the high- voltage plateau, which satisfies various CMS requirements for the efficiency, the noise cluster rate, the fraction of the large signal, and the streamer probability, can be extended at least up to 400 V with the present design. In addition, a simple avalanche multiplication model is studied in detail. The model can reproduce the experimental charge spectra reasonably well. The charge information enables us to estimate the effective Townsend coefficient in avalanche-mode operation.

  4. Synthetic multi-element standards (SMELS) used for the validation of K0-NAA

    International Nuclear Information System (INIS)

    As more and more labs dealing with nuclear analytical techniques are working under a quality assurance system, the need for demonstrating the analytical quality of the method becomes increasingly important. For non-standard methods, such as k0-standardisation Neutron Activation Analysis (k0-NAA), this means a full validation report demonstrating amongst others the bias and the reproducibility of the method and a continuous quality control using appropriate control material. In environmental laboratories using chemical techniques for example several multi-element liquid solutions are available for this purpose. For k0-NAA a set of synthetic multi-element standards (SMELS) was made in cooperation with INW, Gent (B) and IRMM, Geel (B). The SMELS material is based on a phenol formaldehyde resin (Bakelite) that was spiked with 33 different elements. Three types of materials were produced: (1) type I: Au, Cl, Cs, Cu, I, La, Mn and V; forming short-lived radionuclides after irradiation; (2) type II : As, Au, Br, Ce, Mo, Pr, Sb, Th, Yb and Zn; forming medium-lived radionuclides ; (3) type III : Au, Co, Cr, Cs, Fe, In, Sb, Sc, Se, Sr, Th, Tm, Yb, Zn and Zr; forming long-lived radionuclides. These elements have cross-sections and resonance energies with Q0-values ranging from very low to very high and thus serve as quality control of the irradiation facility and the calibration of detectors. The homogeneity of the material was demonstrated by IRMM for a minimum sample intake of 50 mg. In the reactor of Rez near Prague it was proven that the Bakelite matrix has an excellent radiation stability and this up to high fluence density of both thermal and fast neutrons (up to 1.1014 n.cm-2.s-1 and 3.1013 n.cm-2s-1 respectively)

  5. Ageing tests on the low-resistivity RPC for the ALICE dimuon arm

    International Nuclear Information System (INIS)

    The trigger for the Dimuon Forward Spectrometer of the forthcoming ALICE experiment at CERN LHC will be provided by low-resistivity, single gap Resistive Plate Chambers working in streamer mode. Different ageing test were performed to measure and improve the life-time of the detector. Dummy chambers have been built to understand the effects of continuous gas flow upon the Bakelite resistivity: the results concerning our standard gas mixture (49% Ar, 40% forane, 7% isobutane and 4% SF6) are reported, and compared with the same mixture in which ∼1% of water vapor is added. Moreover, two ageing test of 1 month each have been carried out at the Gamma Irradiation Facility at CERN during 2001. The efficiency for cosmic rays under γ irradiation of RPCs coated with different thicknesses of linseed oil was measured. After protracted operation, the detectors have shown an increase of the current and of the background rate. The increase is slower in the chamber with a thicker oil coating

  6. The Muon Spectrometer Barrel Level-1 Trigger of the ATLAS Experiment at LHC

    CERN Document Server

    Aloisio, A; Conventi, F; De Asmundis, R; Izzo, V; Migliaccio, A; Ciapetti, G; Di Mattia, A; Luci, C; Luminari, L; Nisati, A; Pastore, F; Petrolo, E; Vari, R; Veneziano, Stefano; Salamon, A

    2006-01-01

    The proton-proton beam crossing at the LHC accelerator at CERN will have a rate of 40 MHz at the project luminosity. The ATLAS Trigger System has been designed in three levels in order to select only interesting physics events reducing from that rate of 40 MHz to the foreseen storage rate of about 200 Hz. The First Level reduces the output rate to about 100 kHz. The ATLAS Muon Spectrometer has been designed to perform stand-alone triggering and measurement of muon transverse momentum up to 1 TeV/c with good resolution (from 3% at 10 GeV/c up to 10% at 1 TeV/c). In the Barrel region of the Muon Spectrometer the Level-1 trigger is given by means of three layers of Resistive Plate Chamber detectors (RPC): a gaseous detector working in avalanche mode composed by two plates of high-resistivity bakelite and two orthogonal planes of read-out strips. The logic of the Level-1 barrel muon trigger is based on the search of patterns of RPC hits in the three layers consistent with a high transverse momentum muon track ori...

  7. Ageing tests on the low-resistivity RPC for the ALICE dimuon arm

    CERN Document Server

    Arnaldi, R; Barret, V; Bastid, N; Blanchard, G; Chiavassa, E; Cortese, P; Crochet, Philippe; De Marco, N; Dellacasa, G; Drancourt, C; Dupieux, P; Espagnon, B; Ferretti, A; Forestier, B

    2003-01-01

    The trigger for the Dimuon Forward Spectrometer of the forthcoming ALICE experiment at CERN LHC will be provided by low-resistivity, single gap Resistive Plate Chambers working in streamer mode. Different ageing test were performed to measure and improve the life- time of the detector. Dummy chambers have been built to understand the effects of continuous gas flow upon the Bakelite resistivity: the results concerning our standard gas mixture (49% Ar, 40% forane, 7% isobutane and 4% SF//6) are reported, and compared with the same mixture in which similar to 1% of water vapor is added. Moreover, two ageing test of 1 month each have been carried out at the Gamma Irradiation Facility at CERN during 2001. The efficiency for cosmic rays under gamma irradiation of RPCs coated with different thicknesses of linseed oil was measured. After protracted operation, the detectors have shown an increase of the current and of the background rate. The increase is slower in the chamber with a thicker oil coating.

  8. The OPERA muon spectrometers

    International Nuclear Information System (INIS)

    The OPERA experiment will study νμ to ντ oscillations through τ appearance on the 732km long CERN to Gran Sasso baseline. The magnet yokes of the two muon spectrometers are instrumented with 48 planes of high resistivity bakelite Resistive Plate Chambers (RPC) operated in streamer mode. Each plane covers about 70m2. A general introduction to the system installation and commissioning will be given. Four RPC planes were instrumented and the first tests were performed confirming a good behavior of the installed RPCs in terms of intrinsic noise and operating currents. The measured noise maps agree with those obtained in the extensive quality test performed at surface. Counting rates are below 20Hz/m2. Single and multiple cosmic muon tracks were also reconstructed. The estimated efficiency is close to the geometrical limit and the very first measurements of the absolute and differential muon flux are in agreement with the expectations. Finally, a description of the readout electronics and of the slow control system is given

  9. OPERA Resistive Plate Chambers underground test results

    Energy Technology Data Exchange (ETDEWEB)

    Bergnoli, A. [Padova University and INFN, Padova (Italy); Brugnera, R. [Padova University and INFN, Padova (Italy); Candela, A. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Carrara, E. [Padova University and INFN, Padova (Italy); Ciesielski, R. [Padova University and INFN, Padova (Italy); Dal Corso, F. [Padova University and INFN, Padova (Italy); Degli Esposti, L. [Bologna University and INFN, Bologna (Italy); Di Giovanni, A. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); D' Incecco, M. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Di Troia, C. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Dusini, S. [Padova University and INFN, Padova (Italy); Fanin, C. [Padova University and INFN, Padova (Italy); Felici, G. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Gambarara, A. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Garfagnini, A. [Padova University and INFN, Padova (Italy); Gatta, M.; Grianti, F. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Gustavino, C.; Lindozzi, M. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Longhin, A. [Padova University and INFN, Padova (Italy)]. E-mail: longhin@pd.infn.it; Mengucci, A. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Monacelli, P. [L' Aquila University and INFN, l' Aquila (Italy)]|[INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Paoloni, A. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Stanco, L. [Padova University and INFN, Padova (Italy); Tatananni, E. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Terranova, F.; Spinetti, M. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Stipcevic, M.; Sugonyaev, V. [Rudjer Boskovic Institute (IRB), Zagreb (Croatia); Terminiello, L.; Ventura, M.; Votano, L. [INFN Laboratori Nazionali di Frascati, Frascati (Italy)

    2006-08-15

    The OPERA experiment [M. Guler et al., CERN/SPSC 2000-028, SPSC/P318, LNGS P25/2000, July 10, 2000; M. Guler et al., CERN/SPSC 2001-025, SPSC/M668, LNGS-EXP 30/2001 Add. 1/01, August 21, 2001] will study {nu}{sub {mu}}->{nu}{sub {tau}} oscillations through {tau} appearance on the 732 Km long CERN to Gran Sasso baseline. The magnet yokes of the two muon spectrometers are instrumented with 44 layers of high resistivity bakelite Resistive Plate Chambers (RPCs) operated in streamer mode. Each layer covers about 70 m{sup 2}. Four RPC planes were instrumented and the first tests were performed confirming a good behaviour of the installed RPCs in terms of intrinsic noise and operating currents. The measured noise maps agree with those obtained in the extensive quality tests performed at surface. Counting rates are below 20 Hz/m{sup 2}. Single an multiple cosmic muon tracks were also reconstructed. The estimated efficiency is close to the geometrical limit and the very first measurements of the absolute and differential muon flux are in agreement with expectations.

  10. OPERA Resistive Plate Chambers underground test results

    International Nuclear Information System (INIS)

    The OPERA experiment [M. Guler et al., CERN/SPSC 2000-028, SPSC/P318, LNGS P25/2000, July 10, 2000; M. Guler et al., CERN/SPSC 2001-025, SPSC/M668, LNGS-EXP 30/2001 Add. 1/01, August 21, 2001] will study νμ->ντ oscillations through τ appearance on the 732 Km long CERN to Gran Sasso baseline. The magnet yokes of the two muon spectrometers are instrumented with 44 layers of high resistivity bakelite Resistive Plate Chambers (RPCs) operated in streamer mode. Each layer covers about 70 m2. Four RPC planes were instrumented and the first tests were performed confirming a good behaviour of the installed RPCs in terms of intrinsic noise and operating currents. The measured noise maps agree with those obtained in the extensive quality tests performed at surface. Counting rates are below 20 Hz/m2. Single an multiple cosmic muon tracks were also reconstructed. The estimated efficiency is close to the geometrical limit and the very first measurements of the absolute and differential muon flux are in agreement with expectations

  11. The OPERA muon spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Garfagnini, A. [Padova University and INFN, Padova (Italy)]. E-mail: alberto.garfagnini@pd.infn.it; Bergnoli, A. [Padova University and INFN, Padova (Italy); Brugnera, R. [Padova University and INFN, Padova (Italy); Carrara, E. [Padova University and INFN, Padova (Italy); Ciesielski, R. [Padova University and INFN, Padova (Italy); Dal Corso, F. [Padova University and INFN, Padova (Italy); Dusini, S. [Padova University and INFN, Padova (Italy); Fanin, C. [Padova University and INFN, Padova (Italy); Longhin, A. [Padova University and INFN, Padova (Italy); Stanco, L. [Padova University and INFN, Padova (Italy); Cazes, A. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Cecchetti, A. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Di Troia, C. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Dulach, B. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Felici, G. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Mengucci, A. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Orecchini, D. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Paoloni, A. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Spinetti, M. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Terranova, F. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Ventura, M. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Votano, L. [INFN Laboratori Nazionali di Frascati, Frascati (Italy); Candela, A. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); D' Incecco, M. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Gustavino, C. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Lindozzi, M. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy)

    2007-03-01

    The OPERA experiment will study {nu}{sub {mu}} to {nu}{sub {tau}} oscillations through {tau} appearance on the 732km long CERN to Gran Sasso baseline. The magnet yokes of the two muon spectrometers are instrumented with 48 planes of high resistivity bakelite Resistive Plate Chambers (RPC) operated in streamer mode. Each plane covers about 70m{sup 2}. A general introduction to the system installation and commissioning will be given. Four RPC planes were instrumented and the first tests were performed confirming a good behavior of the installed RPCs in terms of intrinsic noise and operating currents. The measured noise maps agree with those obtained in the extensive quality test performed at surface. Counting rates are below 20Hz/m{sup 2}. Single and multiple cosmic muon tracks were also reconstructed. The estimated efficiency is close to the geometrical limit and the very first measurements of the absolute and differential muon flux are in agreement with the expectations. Finally, a description of the readout electronics and of the slow control system is given.

  12. Operation of low-noise single-gap RPC modules exposed to ionisation rates up to 1 kHz/cm$^{2}$

    CERN Document Server

    Cwioka, M; Górski, M; Królikowski, J; 10.1016/j.nima.2004.06.123

    2004-01-01

    Two single gap medium-size RPC modules, made of bakelite plates of very good mechanical quality of the surface and having initial volume resistivity of 1 * 10/sup 10/ Omega cm, were tested in the Gamma Irradiation Facility at CERN at ionisation rates up to 1 kHz/cm/sup 2 /. The internal surfaces facing the gas volume of one RPC module were cladded with a thin layer of linseed oil varnish for comparison of oiled and non-oiled RPC operation. The results refer to the gas mixture of C/sub 2/H/sub 2/F/sub 4//isobutane (97:3) with SF/sub 6/ addition below 1%. The single gap modules exhibited full detection efficiency plateau for the high voltage range of about 1 kV at full intensity of gamma rays. Good timing characteristics allowed to reach 95% efficiency at fully opened irradiation source with time window of 20 ns. The intrinsic noise rate for a non-oiled and an oiled RPC gap was, respectively, below 5 and 1 Hz/cm/sup 2/ at full efficiency over 1 kV voltage range.

  13. Operation of low-noise single-gap RPC modules exposed to ionisation rates up to 1 kHz/cm$^2$

    CERN Document Server

    Cwiok, M; Górski, M; Królikowski, J

    2004-01-01

    Two single gap medium-size RPC modules, made of bakelite plates of very good mechanical quality of the surface and having initial volume resistivity of 1 multiplied by 10**1**0 omegacm, were tested in the Gamma Irradiation Facility at CERN at ionisation rates up to 1 kHz/cm **3. The internal surfaces facing the gas volume of one RPC module were cladded with a thin layer of linseed oil varnish for comparison of oiled and non-oiled RPC operation. The results refer to the gas mixture of C//2H//2F //4/isobutane (97:3) with SF//6 addition below 1%. The single gap modules exhibited full detection efficiency plateau for the high voltage range of about 1 kV at full intensity of gamma rays. Good timing characteristics allowed to reach 95% efficiency at fully opened irradiation source with time window of 20 ns. The intrinsic noise rate for a non-oiled and an oiled RPC gap was, respectively, below 5 and 1 Hz/cm**2 at full efficiency over 1 k V voltage range.

  14. A low resistivity RPC for the trigger of the ALICE di-muon arm

    CERN Document Server

    Ferretti, A; Baldit, A; Barret, V; Bastid, N; Blanchard, G; Chiavassa, E; Cortese, P; Crochet, Philippe; Dellacasa, G; De Marco, N; Drancourt, C; Dupieux, P; Espagnon, B; Forestier, B; Gallio, M; Genoux-Lubain, A; Insa, C; Jouve, F; Lamoine, L; Lefèvre, F; Manso, F; Mereu, P; Musso, A; Oppedisano, C; Piccotti, A; Rosnet, P; Royer, L; Saturnini, P; Scalas, E; Scomparin, E; Sigaudo, F; Vercellin, Ermanno

    2001-01-01

    Resistive Plate Chambers (RPC) operated in streamer mode are expected to provide the trigger of the ALICE dimuon forward spectrometer. To match the requirements concerning the rate capability (about 100 Hz/cm2, including a large safety factor), several prototypes have been realized with low-resistivity Bakelite electrodes and a strongly quenching gas mixture. Duringb eam and irradiation tests the detector has shown a stable behaviour and excellent rate capability (up to 1 kHz/cm 2 in eam tests) with a cluster size close to one. In addition to that,a new discrimination technique with a dual threshold has been devised: with this method, a time resolution comparable with the one typical of the avalanche mode can be obtained as soon as the applied voltage is sufficient for the RPC to reach full efficiency. In the presentation the performances of the detector will be reported, together with the results of ageing tests performed at the Gamma Irradiation Facility at CERN.

  15. Ultra fast timing MMRPC: a versatile detector for basic and applied science

    International Nuclear Information System (INIS)

    Three decades ago the Resistive Plate Chamber (RPC) was invented to overcome several problems of parallel plate chambers. Unlike parallel plate chambers, electrodes of RPCs are made of resistive material like Bakelite or float glass. This has the effect that only a limited part of the electrode is discharged during the passage of an ionizing particle with subsequent avalanches or streamers, while the rest of the electrode remains unchanged. Wide and/or single gap RPC detectors are used in many large scale experiments to explore various directions of science. This includes fundamental research in particle physics, in astrophysics, in cosmology etc,. In India, RPC detectors array (INO) will play a vital role in the measurement of mass hierarchy of three flavors of neutrino mass. To improve timing resolution, Multigap Resistive Plate Chamber (MRPC) is an intelligent modification of an RPC by increasing the electric field across the gap and creating thinner layers of gas gap by inserting (electrostatically) floating glasses between anode and cathode. It can be shown that a resolution in the range of 50-100 ps is achievable with gaps of 200-300 mm. Moreover, RPCs are insensitive to the magnetic field. Finally timing RPCs have already proved in the last years to be a reliable and stable detector with sensitive larger and regularly used in a large number of experiments

  16. Biomorphous SiC ceramics prepared from cork oak as precursor

    Science.gov (United States)

    Yukhymchuk, V. O.; Kiselov, V. S.; Valakh, M. Ya.; Tryus, M. P.; Skoryk, M. A.; Rozhin, A. G.; Kulinich, S. A.; Belyaev, A. E.

    2016-04-01

    Porous ceramic materials of SiC were synthesized from carbon matrices obtained via pyrolysis of natural cork as precursor. We propose a method for the fabrication of complex-shaped porous ceramic hardware consisting of separate parts prepared from natural cork. It is demonstrated that the thickness of the carbon-matrix walls can be increased through their impregnation with Bakelite phenolic glue solution followed by pyrolysis. This decreases the material's porosity and can be used as a way to modify its mechanical and thermal characteristics. Both the carbon matrices (resulted from the pyrolysis step) and the resultant SiC ceramics are shown to be pseudomorphous to the structure of initial cork. Depending on the synthesis temperature, 3C-SiC, 6H-SiC, or a mixture of these polytypes, could be obtained. By varying the mass ratio of initial carbon and silicon components, stoichiometric SiC or SiC:С:Si, SiC:С, and SiC:Si ceramics could be produced. The structure, as well as chemical and phase composition of the prepared materials were studied by means of Raman spectroscopy and scanning electron microscopy.

  17. Doppler Broadening Calculations of Compton Scattering for Molecules, Plastics, Tissues, and Few Biological Materials in the X-Ray Region: An Analysis in Terms of Compton Broadening and Geometrical Energy Broadening

    Science.gov (United States)

    Rao, D. V.; Cesareo, R.; Brunetti, A.; Gigante, G. E.; Akatsuka, T.; Takeda, T.; Itai, Y.

    2004-09-01

    Relativistic and nonrelativistic Compton profile cross sections for H, C, N, O, P, and Ca and for a few important biological materials such as water, polyethylene, lucite, polystyrene, nylon, polycarbonate, bakelite, fat, bone and calcium hydroxyapatite are estimated for a number of Kα x-ray energies and for 59.54 keV (Am-241) γ photons. Energy broadening and geometrical broadening (ΔG) is estimated by assuming θmin and θmax are symmetrically situated around θ=90°. FWHM of J(PZ) and FWHM of Compton energy broadening are evaluated at various incident photon energies. These values are estimated around the centroid of the Compton profile with an energy interval of 0.1 and 1.0 keV for 59.54 keV photons. Total Compton, individual shell, and Compton energy-absorption scattering cross sections are evaluated in the energy region from 0.005 to 0.5 MeV. It is an attempt to know the effect of Doppler broadening for single atoms, many of which constitute the biological materials.

  18. Effective atomic numbers of some H-, C-, N- and O-based composite materials derived from differential incoherent scattering cross-sections

    Indian Academy of Sciences (India)

    S Prasanna Kumar; V Manjunathaguru; T K Umesh

    2010-04-01

    In this work, we have made an effort to determine whether the effective atomic numbers of H-, C-, N- and O-based composite materials would indeed remain a constant over the energy grid of 280–1200 keV wherein incoherent scattering dominates their interaction with photons. For this purpose, the differential incoherent scattering cross-sections of Be, C, Mg, Al, Ca and Ti were measured for three scattering angles 60°, 80° and 100° at 279.1, 661.6 and 1115.5 keV using which an expression for the effective atomic number was derived. The differential incoherent scattering cross-sections of the composite materials of interest measured at these three angles in the same set-up and substituted in this expression would yield their effective atomic number at the three energies. Results obtained in this manner for bakelite, nylon, epoxy, teflon, perspex and some sugars, fatty acids as well as amino acids agreed to within 2% of some of the other available values. It was also observed that for each of these samples, eff was almost a constant at the three energies which unambiguously justified the conclusions drawn by other authors earlier [Manjunathaguru and Umesh, J. Phys. B: At. Mol. Opt. Phys. 39, 3969 (2006); Manohara et al, Nucl. Instrum. Methods B266, 3906 (2008); Manohara et al Phys. Med. Biol. 53, M377 (2008)] based on total interaction cross-sections in the energy grid of interest.

  19. Doppler broadening calculations of Compton scattering for molecules, plastics, tissues, and few biological materials in the X-ray region: An analysis in terms of Compton broadening and geometrical energy broadening

    International Nuclear Information System (INIS)

    Relativistic and nonrelativistic Compton profile cross sections for H, C, N, O, P, and Ca and for a few important biological materials such as water, polyethylene, lucite, polystyrene, nylon, polycarbonate, bakelite, fat, bone and calcium hydroxyapatite are estimated for a number of Kα x-ray energies and for 59.54 keV (Am-241) γ photons. Energy broadening and geometrical broadening (ΔG) is estimated by assuming θmin and θmax are symmetrically situated around θ=90 deg. FWHM of J(PZ) and FWHM of Compton energy broadening are evaluated at various incident photon energies. These values are estimated around the centroid of the Compton profile with an energy interval of 0.1 and 1.0 keV for 59.54 keV photons. Total Compton, individual shell, and Compton energy-absorption scattering cross sections are evaluated in the energy region from 0.005 to 0.5 MeV. It is an attempt to know the effect of Doppler broadening for single atoms, many of which constitute the biological materials

  20. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2013-01-01

    During LS1, the Resistive Plate Chamber (RPC) collaboration is focusing its efforts on installation and commissioning of the fourth endcap station (RE4) and on the reparation and maintenance of the present system (1100 detectors). The 600 bakelite gaps, needed to build 200 double-gap RE4 chambers are being produced in Korea. Chamber construction and testing sites are located at CERN, in Ghent University, and at BARC (India). At present, 42 chambers have been assembled, 32 chambers have been successfully tested with cosmic rays runs and 7 Super Modules, made by two chambers, have been built at CERN by a Bulgarian/Georgian/Italian team and are now ready to be installed in the positive endcap. The 36 Super Modules needed to complete the positive endcap will be ready in September and installation is scheduled for October 2013. The Link-Board system for RE4 is under construction in Naples. Half of the system has been delivered at CERN in June. Six crates (Link-Board Boxes) and 75 boards, needed to instrument t...

  1. Komposit Laminate Rami Epoksi Sebagai Bahan Alternatif Socket Prosthesis

    Directory of Open Access Journals (Sweden)

    Agustinus P. Irawan

    2009-01-01

    Full Text Available pure plant oil, biofuel, coconut oil, palm oil, jatropha oilSocket is the most important component in a prosthesis making. Performance criteria for prosthetic socket material include strength, durability, minimal weight, comfort, and minimal fabrication cost. This research attempts to analyze the strength of ramie fiber reinforced epoxy laminate composite as an alternative of socket prosthesis. The research based on ASTM D 3039/D 3039M for tensile strength and ASTM D 695 for compressive strength. The ramie fiber used was a continuous fiber 100 % Ne14'S, with Epoxy Resin Bakelite EPR 174 and Epoxy Hardener V-140. The sample test was created using a hand lay-up method. The result of this research is presented in a correlation of finsile strength (st, compression strength (sc, elasticity modulus (E versus fraction volume of fiber (Vf. The result is then being compared with some of the prosthesis material’s strength produced by Otto Bock. The analysis was completed with the mode of the failure observation by using Scanning Electron Microscope (SEM. The result concludes that the ramie fiber reinforced epoxy laminate composite is potentially developed further as a socket prosthesis material on Vf 40 – 50 %. Tensile strength and specific strength that has been generated was higher than that of several materias for socket prosthesis, including fiberglass. The mode of the failure found were a brittle failure on Vf: 10-30%, debonding and delamination on Vf: 40-50%. Abstract in Bahasa Indonesia: Socket merupakan bagian terpenting dalam pembuatan prosthesis. Kriteria bahan socket prosthesis antara lain kekuatan, ketahanan, ringan, kenyamanan dan biaya produksi yang rendah. Penelitian ini bertujuan menganalisis kekuatan komposit laminate berpenguat serat rami epoksi sebagai bahan alternatif socket prosthesis. Pengujian kekuatan mengacu standar ASTM D 3039/D 3039M uji tarik dan ASTM D 695 uji tekan. Serat rami yang digunakan berupa serat kontinyu jenis

  2. 分子蒸馏双酚A环氧树脂的性能研究%Research on the performance of molecular distillation bisphenol- A epoxy resin

    Institute of Scientific and Technical Information of China (English)

    夏宇; 陶纯初; 汝国兴; 张犇

    2012-01-01

    The bisphenol A epoxy resin with trademark JF -9955A was obtained by the molecular distillation of common commercial 128 epoxy resin removed the ligtht distillate and polymer heavy distillate. The JF -9955A was compared with Dow DER 332 and Bakelite EPR 162 high purity bisphenol A epoxy resins by the analysis of FT - IR and liquid chromatography, testings of basic properties and Na + content detection. The product properties of the three epoxy resins cured with anhydride were also tested. The results showed that JF - 9955A had low viscosity, high purity, low contents of hydrolyzable chlorine and other ions. The performance indicators of JF -9955A reached the level of similar foreign products.%采用普通市售128环氧树脂经过分子蒸馏,去除轻馏分和多聚体重组分后,得到双酚A分子环氧树脂,牌号为JF-9955A。通过红外光谱和液相色谱分析,基础性能和Na+含量检测以及对其酸酐固化物性能的测试将JF-9955A与国外陶氏化学的DER 332、BakeliteEPR 162高纯度双酚A环氧树脂进行了对比。结果表明,JF-9955A具有粘度低,纯度高,可水解氯及其他离子杂质含量低等特点,各项性能指标达到国外同类产品水平。

  3. Effective atomic numbers for photon energy absorption of some low-Z substances of dosimetric interest

    International Nuclear Information System (INIS)

    Effective atomic numbers for photon energy absorption (ZPEAeff) and effective atomic numbers for photon interaction (ZPIeff) of some low-Z substances of dosimetric interest such as A-150 tissue-equivalent plastic (A150TEP), alanine, bakelite, Gafchromic sensor (GS), plastic scintillator (PS), polyethylene, mylar, polystyrene, perspex, radiochromic dye film nylon base (RDF : NB), tissue-equivalent gas-methane based (TEG : MB) and tissue-equivalent gas-propane based (TEG : PB) have been calculated by a direct method in the energy region of 1 keV-20 MeV. Experimental mass attenuation coefficients and ZPIeff of some of these substances at selected photon energies of 26.34, 33.2, and 59.54 keV have been obtained and compared with theoretical values. The ZPEAeff and ZPIeff values steadily increases up to 6-15 keV, and then they steadily decrease up to 600-1500 keV for all the substances studied. From 1.5 MeV, the values increases with increase in energy up to 20 MeV. Significant differences up to 33.68% exist between ZPIeff and the ZPEAeff in the energy region of 10-150 keV. The single effective atomic numbers obtained using the program XMuDat (ZXMUDATeff ) are found to be significantly higher compared to those of ZPEAeff and ZPIeff values in the entire energy of interest for all the substances studied. The directly calculated ZPEAeff and ZPIeff values vary with energy compared to the energy-independent effective atomic numbers predicted by various theoretical expressions. The effects of absorption edges on effective atomic numbers and their variation with photon energy and the possibility of defining two set values of effective atomic numbers below the absorption edges of elements present in the composite substances are discussed

  4. Mechanisms affecting performance of the BaBar resistive plate chambers and searches for remediation

    International Nuclear Information System (INIS)

    The BaBar experiment at PEPII relies on the instrumentation of the flux return (IFR) for both muon identification and KL detection. The active detector is composed of resistive plate chambers (RPCs) operated in streamer mode. Since the start of operation the RPCs have suffered persistent efficiency deterioration and dark current increase problems. The 'autopsy' of bad BaBar RPCs revealed that in many cases uncured linseed oil droplets had formed on the inner surface of the Bakelite plates, leading to current paths from oil 'stalagmites' bridging the 2 mm gap. In this paper, a possible model of this 'stalagmite' formation and its effect on the dark current and efficiency of RPC chambers is presented. Laboratory test results strongly support this model. Based upon this model we are searching for solutions to eliminate the unfavorable effect of the oil stalagmites. The lab tests show that the stalagmite resistivity increases dramatically if exposed to the air, an observation that points to a possible way to remedy the damage and increase the efficiency. We have seen that flowing an oxygen gas mixture into the chamber helps to polymerize the uncured linseed oil. Consequently, the resistivity of the bridged oil stalagmites increases, as does that of the oil coating on the frame edges and spacers, significantly reducing the RPC dark currents and low-efficiency regions. We have tested this idea on two chambers removed from BaBar because of their low efficiency and high dark current. These test results are reported in the paper, and two other remediation methods also mentioned. We continue to study this problem, and try to find new treatments with permanent improvement

  5. Zircon products for stopperless casting of steel

    International Nuclear Information System (INIS)

    A description is given of the technology for making experimental series of zirconium parts for gate valves used in steel pouring ladles which have been tested at the Dneprovsk steel foundry. A diagram is presented for the production of parts used for continuous teeming of steel. The furnace charge for making the parts consists of 50% of ground briquette, fractions 2.8-0.5 mm, and 50% of a finely ground mixture of briquette and clay. Iron impurities introduced to the charge during grinding are removed by magnetic separation. The parts are made with the aid of a friction press (250 t/cm2). They are kept at ambient temperatures for 24 hours followed by drying at 85-110 deg C. Calcination has been carried out according to Dinas conditions: maximum temperature 1405-1415 deg C, calcination period 74-94 hours, including a delay of 38-52 hours during the heating and cooling period. The calcined parts are soaked with bakelite lacquer in a special setup and then subjected to thermal treatment in a tunnel dryer at 120-140 deg C for 11-12 hours. The contact surfaces are polished on surface-grinding machine 2B722 by using a diamond disk. The finished zirconium parts have the following characteristics: limiting strength on compression 800-980 kg/cm2, open porosity-10-10.3%, concentration of ZrO2-56.81% by wt., concentration of Al2O3-4.35% by wt. Testing of these parts in 100-t ladles for pouring semikilled and rimmed steel have given satisfactory results

  6. Performance evaluation of a dedicated computed tomography scanner used for virtual simulation using in-house fabricated CT phantoms

    International Nuclear Information System (INIS)

    Comprehensive tests on single slice CT scanner was carried out using in-house fabricated phantoms/test tools following AAPM recommended methods to independently validate the auto-performance test (APT) results. Test results of all the electromechanical parameters were found within the specified limits. Radiation and sensitivity profile widths were within ± 0.05 cm of the set slice thickness. Effective energy corresponding to nominal kVp of 80, 110 and 130 were 49.99, 55.08 and 59.48 keV, respectively. Percentage noise obtained by APT was 1.32% while the independently measured value was 0.38%. Observed contrast resolutions by independent method at 0.78% and 12% contrast difference were 4 mm and 1.25 mm ( = 4 Ip/cm) respectively. However, high contrast resolution (limiting spatial resolution) by APT at 50, 10 and 2% MTF levels were 9, 12.5 and 14.1 Ip/cm respectively. Difference in calculated and measured CT numbers of water, air, teflon, acrylic, polystyrene and polypropylene were in the range of 0 to 24 HU, while this difference was 46 and 94 HU in case of nylon and bakelite respectively. The contrast scale determined using CT linearity phantom was 1.998 x 10-4 cm-1/CT number. CT dose index (CTDI) and weighted CTDI (CTDlw) measured at different kVp for standard head and body phantoms were smaller than manufacturer-specified and system-calculated values and were found within the manufacturer-specified limit of ± 20%. Measured CTDIs on surface (head: 3.6 cGy and body: 2.6 cGy) and at the center (3.3 cGy, head; and 1.2 cGy, body) were comparable to reported values of other similar CT scanners and were also within the industry-quoted CTDI range. Comprehensive QA and independent validation of APT results are necessary to obtain baseline data for CT virtual simulation. (author)

  7. A facile method to synthesize carbon coated Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} with improved performance

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yunjian, E-mail: lyjian122331@yahoo.com.cn [School of Material Science and Technology Jiangsu University, Zhenjiang (China); Automobile Engineering Research Institute Jiangsu University, Zhenjiang (China); Gao, Yanyong; Lv, Jun [School of Material Science and Technology Jiangsu University, Zhenjiang (China); Chen, Long [Automobile Engineering Research Institute Jiangsu University, Zhenjiang (China)

    2013-11-15

    Graphical abstract: Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} powders are synthesized and then coated by decomposed carbon. The discharge capacity of carbon-coated cathode at 0.1 and 5 C are 246 and 125 mAhg{sup −1}, while those of ball-milled cathode are 222 and 49 mAhg{sup −1}. - Highlights: • A simple method was applied to synthesize carbon-coated Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2}. • The discharge capacities of carbon-coated sample at 0.1 and 5.0 C rates are 246 and 125 mAh/g. • Capacity retention of carbon-coated electrode after 50 cycles is 97.5%. - Abstract: Carbon-coated Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} powders have been synthesized with Bakelite and heat process in air. The effect of carbon coating on the physical and electrochemical properties have been discussed through the characterizations of X-ray diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), discharge and rate tests. The carbon-coated cathode exhibits much improved first discharge capacity and rate capability than the pristine sample. The discharge capacity at 0.1 and 5.0 C rates are 246 and 125 mAhg{sup −1}, while that of pristine are only about 222 and 49 mAhg{sup −1}, respectively. The capacity retention of Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} electrode after 50 cycles is improved from 89.8 to 97.5% after carbon coating. EIS results indicate that R{sub ct} of Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} electrode is decreased from 62 to 37 Ω after carbon coating.

  8. ZZ SIGMNA-A, Photon Interaction and Absorption Cross-Section Library

    International Nuclear Information System (INIS)

    1 - Description of program or function: - Format: special format; - Number of groups: Photon interaction and absorption coefficients covering the energy range 1 KeV to 100 MeV. - Nuclides: Materials: A150TE PLAST (H, C, N, O, F, Ca); Ac; Air (N, O, Ar); Sb; Ar; As; At; Bakelite (C, H, O); Ba; BARSO4; Be; Bk; Bi; Bone (H, C, N, O, Mg, P, S, Ca); B; Br; C552SHONKA P (H, C, O, F, Si); Cd; Ca; Cf; CAPINTEC (H, C, O, F, Si); C; Ce; Cs; Cl; Cr; Co; Concrete (H, O, Na, Mg, Al, Si, S, K, Ca, Fe); Cu; Cm; Delrin (C, H, O); Dy; Er; Eu; Fat (H, C, N, O, S); F; Fr; FRICK8 (H, O, Na, S, Cl, Fe); Gd; Ga; Ge; Au; Hf; He; Ho; H; ICRP Cortical bone (H, C, N, O, Mg, P, S, Ca, Zn); ICRP Tissue (H, C, N, O, S, Mg, P, S, Cl, K, Ca, Fe, Zn); ICRU Tissue (H, C, N, O); In; I; Ir; Fe; Kr; Pb; LIFTLD (Li, F); Li; Lucite (C, H, O); Lu; Mg; Mn; Hg; Mo; Muscle (H, C, N, O, S, Mg, P, S, K, Ca); Nd; Ne; Np; Ni; Nb; N; Nylon (H, C, N, O); O; Pd; P; Pt; Pu; Po; Polyethylene (C, H); Polystyrene (C, H); K; Pr; Pm; Pa; Ra; Re; Rh; Rb; Ru; Sm; Sc; Se; Si; Ag; Sodium-iodide; Na; SOLWA1; SOLWA2; Sr; S; Ta; Te; Tb; Tl; Th; Tm; Sn; Ti; W; U; V; Water (H, O); Xe; Yb; Y; Zn; Zr. - Origin: Howerton, JRC. An extensive library of photon interaction coefficients has been developed by the Ontario Cancer Institute, Toronto, Ontario, Canada, based on the compilation of Plechaty, Cullen, and Howerton. In addition to partial cross section data, the following are given: mass attenuation coefficients, mass energy transfer coefficients, mass energy absorption coefficients, average energy transferred to electrons, average energy absorbed per interaction, and average stopping power of electrons. Partial interaction coefficients and absorption coefficients are useful in any radiation transport or other radiation analysis application. The data from the Ontario Cancer Institute are given for 94 elements and 25 composite materials covering the energy range 1 KeV to 100 MeV. The reactions considered are coherent and