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Sample records for buc xa gamma

  1. Overview on the BUC activities at the IAEA

    International Nuclear Information System (INIS)

    Full text: Due to the worldwide interest and broad applicability of BUC for spent fuel management, the International Atomic Energy Agency (IAEA) has taken an active interest in the subject. The IAEA role has been one of an observer and disseminator of appropriate information. In 1997, the International Atomic Energy Agency (IAEA) started a task to monitor the implementation of BUC in spent fuel management systems, to provide a forum to exchange information, to discuss the matter and to gather and disseminate information on the status of national practices of BUC implementation in the Member States. The task addressed current and future aspects of BUC. In October 1997, the IAEA organized an advisory group meeting (AGM) to examine and report on the status of BUC for storage, transport, reprocessing, and disposal of PWR, BWR, WWER, RBMK and MOX spent fuel. Since the proceedings of the AGM were published in April 1998 (IAEA-TECDOC-1013), significant developments have served to advance the use of BUC throughout the world. Experts from countries with nuclear programmes that range from very small to very large have made important contributions. The use of BUC has progressed along the lines of greatest need. In the following years, several consultancies were held to monitor the progress in BUC implementation. (July and December 1998, July 1999 and July 2001). The results of these meetings were published in three Working Materials. A technical committee Meeting (TCM) on the Evaluation and Review of the Implementation of BUC in Spent Fuel Management Systems was held in July 2000 in Vienna with 35 experts from 17 countries and 2 international organizations. The purpose of this TCM was to survey the progress and status of international activities related to the use of BUC for spent fuel applications. The current BUC applications status and the BUC level implemented in each application were collected and published in Tables. Conclusions of the TCM. During the closing session of

  2. Clinical Scenarios for Discordant Anti-Xa

    OpenAIRE

    Jesus Vera-Aguilera; Hindi Yousef; Diego Beltran-Melgarejo; Teng Hugh Teng; Ramos Jan; Mary Mok; Carlos Vera-Aguilera; Eduardo Moreno-Aguilera

    2016-01-01

    Anti-Xa test measures the activity of heparin against the activity of activated coagulation factor X; significant variability of anti-Xa levels in common clinical scenarios has been observed. Objective. To review the most common clinical settings in which anti-Xa results can be bias. Evidence Review. Guidelines and current literature search: we used PubMed, Medline, Embase, and MEDION, from 2000 to October 2013. Results. Anti-Xa test is widely used; however the assay underestimates heparin co...

  3. BUC validation in the UK: Design of experiments and lessons learnt

    International Nuclear Information System (INIS)

    The history, design, implementation and analysis of experiments related to the validation of BUC in the UK are summarized and reviewed. The experiments include the CERES programme, which was carried out in the UK (at the DIMPLE facility, Winfrith) and in France (at the MINERVE reactor, Cadarache). Measurements of the reactivity of irradiated PWR, BWR and AGR fuel samples were made in a variety of neutron spectra, designed to simulate a range of spent fuel environments. PIE data for actinides and the major fission product absorbers were also obtained. Lessons learnt during the programme are presented. These include the main conclusions drawn from the code validation analyses and also identify some technical difficulties encountered during the implementation of the programme. Suggestions are made regarding how future programmes might strengthen the validation base. (author)

  4. Clinical Scenarios for Discordant Anti-Xa

    Directory of Open Access Journals (Sweden)

    Jesus Vera-Aguilera

    2016-01-01

    Full Text Available Anti-Xa test measures the activity of heparin against the activity of activated coagulation factor X; significant variability of anti-Xa levels in common clinical scenarios has been observed. Objective. To review the most common clinical settings in which anti-Xa results can be bias. Evidence Review. Guidelines and current literature search: we used PubMed, Medline, Embase, and MEDION, from 2000 to October 2013. Results. Anti-Xa test is widely used; however the assay underestimates heparin concentration in the presence of significant AT deficiency, pregnancy, end stage renal disease, and postthrombolysis and in patients with hyperbilirubinemia; limited published data evaluating the safety and effectiveness of anti-Xa assays for managing UH therapy is available. Conclusions and Relevance. To our knowledge this is the first paper that summarizes the most common causes in which this assay can be affected, several “day to day” clinical scenarios can modify the outcomes, and we concur that these rarely recognized scenarios can be affected by negative outcomes in the daily practice.

  5. Clinical Scenarios for Discordant Anti-Xa

    Science.gov (United States)

    Vera-Aguilera, Jesus; Yousef, Hindi; Beltran-Melgarejo, Diego; Teng, Teng Hugh; Jan, Ramos; Mok, Mary; Vera-Aguilera, Carlos; Moreno-Aguilera, Eduardo

    2016-01-01

    Anti-Xa test measures the activity of heparin against the activity of activated coagulation factor X; significant variability of anti-Xa levels in common clinical scenarios has been observed. Objective. To review the most common clinical settings in which anti-Xa results can be bias. Evidence Review. Guidelines and current literature search: we used PubMed, Medline, Embase, and MEDION, from 2000 to October 2013. Results. Anti-Xa test is widely used; however the assay underestimates heparin concentration in the presence of significant AT deficiency, pregnancy, end stage renal disease, and postthrombolysis and in patients with hyperbilirubinemia; limited published data evaluating the safety and effectiveness of anti-Xa assays for managing UH therapy is available. Conclusions and Relevance. To our knowledge this is the first paper that summarizes the most common causes in which this assay can be affected, several “day to day” clinical scenarios can modify the outcomes, and we concur that these rarely recognized scenarios can be affected by negative outcomes in the daily practice. PMID:27293440

  6. Phenyltriazolinones as potent factor Xa inhibitors.

    Science.gov (United States)

    Quan, Mimi L; Pinto, Donald J P; Rossi, Karen A; Sheriff, Steven; Alexander, Richard S; Amparo, Eugene; Kish, Kevin; Knabb, Robert M; Luettgen, Joseph M; Morin, Paul; Smallwood, Angela; Woerner, Francis J; Wexler, Ruth R

    2010-02-15

    We have discovered that phenyltriazolinone is a novel and potent P1 moiety for coagulation factor Xa. X-ray structures of the inhibitors with a phenyltriazolinone in the P1 position revealed that the side chain of Asp189 has reoriented resulting in a novel S1 binding pocket which is larger in size to accommodate the phenyltriazolinone P1 substrate. PMID:20100660

  7. La poesía bucólica en época de Nerón : lectura virgiliana, ideología senequiana y propaganda imperial

    OpenAIRE

    Ruiz Arzalluz, Iñigo

    1993-01-01

    [ES] Durante los pocos años del gobierno de Nerón la poesía bucólica latina experimenta un auge anormal y desarrolla una función propagandística particularmente clara. En este artículo se trata de reconstruir, a partir de textos que hasta ahora no se habían implicado debidamente en la cuestión (cuarta égloga de Virgilio, Apocolocyntosis de Séneca, etc.), las motivaciones inmediatas de este resurgir del género: la poesía bucólica de la época responde en parte a una invitación expresa que Sénec...

  8. The new factor Xa inhibitor: Apixaban

    Directory of Open Access Journals (Sweden)

    Sangeeta Bhanwra

    2014-01-01

    Full Text Available Cardiovascular diseases are still the most important cause of morbidity and mortality worldwide and anti-thrombotic treatment is widely used as a result. The currently used drugs include heparin and its derivatives, vitamin K antagonists, though efficacious, have their own set of limitations like unpredictable pharmacokinetic profile, parenteral route (with heparin and its derivatives only, narrow therapeutic window, and constant laboratory monitoring for their efficacy and safety. This lead to the development of novel factor Xa inhibitors which could be given orally, have predictable dose response relationship and are associated with lesser hemorrhagic complications. They include rivaroxaban, apixaban, and edoxaban among others. Apixaban has currently been approved for use in patients undergoing total knee or hip replacement surgery and to prevent stroke in patients with atrial fibrillation. Many trials are ongoing for apixaban to firmly establish its place in future, among the anti-thrombotic drugs.

  9. Pharmacodynamics and Pharmacokinetics of oral factor Xa inhibitors

    OpenAIRE

    Persson PB

    2015-01-01

    Pontus B Persson Institute of Vegetative Physiology, Berlin, GermanyApixaban and rivaroxaban are oral factor Xa inhibitors. In a recent issue of Clinical Pharmacology: Advances and Applications, Frost et al compare apixaban (2.5 mg, twice daily) to rivaroxaban (10 mg, once daily) with regard to their pharmacokinetics and pharmacodynamics.1 Both oral factor Xa inhibitors have similar half-lives. Moreover, as may seem intuitive, the twice daily regime of apixaban revealed a less pronounced peak...

  10. Transcriptional Characteristics of Xa21-mediated Defense Responses in Rice

    Institute of Scientific and Technical Information of China (English)

    Qiang Gan; Hui Bai; Xianfeng Zhao; Yong Tao; Haipan Zeng; Yuning Han; Wenyuan Song; Lihuang Zhu; Guozhen Liu

    2011-01-01

    Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is the most destructive bacterial disease of rice. The cloned rice gene Xa21 confers resistance to a broad spectrum of Xoo races. To identify genes involved in Xa21-mediated immunity, a whole-genome oligonucleotide microarray of rice was used to profile the expression of rice genes between incompatible interactions and mock treatments at 0, 4, 8, 24, 72 and 120 h post inoculation (hpi) or between incompatible and compatible interactions at 4 hpi, respectively. A total of 441 differentially expressed genes, designated as XDGs (Xa21 mediated differentially expressed genes), were identified. Based on their functional annotations, the XDGs were assigned to 14 categories, including defense-related, signaling, transcriptional regulators. Most of the defense-related genes belonged to the pathogenesis-related gene family, which was induced dramatically at 72 and 120 hpi. Interestingly, most signaling and transcriptional regulator genes were downregulated at 4 and 8 hpi, suggesting that negative regulation of cellular signaling may play a role in the Xa21-mediated defense response. Comparison of expression profiles between Xa21- and other R gene-mediated defense systems revealed interesting common responses. Representative XDGs with supporting evidences were also discussed.

  11. Marker-aided Incorporation of Xa38, a Novel Bacterial Blight Resistance Gene, in PB1121 and Comparison of its Resistance Spectrum with xa13 + Xa21.

    Science.gov (United States)

    Ellur, Ranjith K; Khanna, Apurva; S, Gopala Krishnan; Bhowmick, Prolay K; Vinod, K K; Nagarajan, M; Mondal, Kalyan K; Singh, Nagendra K; Singh, Kuldeep; Prabhu, Kumble Vinod; Singh, Ashok K

    2016-01-01

    Basmati rice is preferred internationally because of its appealing taste, mouth feel and aroma. Pusa Basmati 1121 (PB1121) is a widely grown variety known for its excellent grain and cooking quality in the international and domestic market. It contributes approximately USD 3 billion to India's forex earning annually by being the most traded variety. However, PB1121 is highly susceptible to bacterial blight (BB) disease. A novel BB resistance gene Xa38 was incorporated in PB1121 from donor parent PR114-Xa38 using a modified marker-assisted backcross breeding (MABB) scheme. Phenotypic selection prior to background selection was instrumental in identifying the novel recombinants with maximum recovery of recurrent parent phenome. The strategy was effective in delimiting the linkage drag to <0.5 mb upstream and <1.9 mb downstream of Xa38 with recurrent parent genome recovery upto 96.9% in the developed NILs. The NILs of PB1121 carrying Xa38 were compared with PB1121 NILs carrying xa13 + Xa21 (developed earlier in our lab) for their resistance to BB. Both NILs showed resistance against the Xoo races 1, 2, 3 and 6. Additionally, Xa38 also resisted Xoo race 5 to which xa13 + Xa21 was susceptible. The PB1121 NILs carrying Xa38 gene will provide effective control of BB in the Basmati growing region. PMID:27403778

  12. Evaluation of a Heparin-Calibrated Antifactor Xa Assay for Measuring the Anticoagulant Effect of Oral Direct Xa Inhibitors.

    Science.gov (United States)

    Beyer, Jacob; Trujillo, Toby; Fisher, Sheila; Ko, Ann; Lind, Stuart E; Kiser, Tyree H

    2016-07-01

    The introduction of oral direct anti-Xa anticoagulants apixaban and rivaroxaban has significantly impacted the treatment and prevention of thromboembolic disease. Clinical scenarios exist in which a quantitative assessment for degree of anticoagulation due to these agents would aid management. The purpose of this work was to evaluate the chromogenic antifactor Xa assay calibrated with heparin standards at our institution for assessment of intensity of anticoagulation with rivaroxaban or apixaban in addition to its current use for unfractionated heparin or low-molecular-weight heparin. We also aimed to propose expected steady state peak and trough antifactor Xa activities for these agents based upon dosing regimens approved for nonvalvular atrial fibrillation. Antifactor Xa activity correlated very strongly with apixaban and rivaroxaban concentration in both spiked samples and treated patient plasma samples (r (2) = .99, P < .001). This correlation was observed over a broad range (20-500 ng/mL) of drug concentrations, as sample dilution with pooled normal plasma significantly extended the range of quantitative assessment. Based on drug concentrations previously published in pharmacokinetic studies, the expected steady state peak and trough antifactor Xa activity ranges for apixaban are 1.80 to 2.20 IU/mL and 0.70 to 1.10 IU/mL, respectively. For rivaroxaban, these ranges are 3.80 to 6.20 IU/mL and 0.60 to 1.00 IU/mL, respectively. In conclusion, our findings demonstrate that heparin-calibrated antifactor Xa activity correlates strongly with apixaban and rivaroxaban concentration. The dilution of samples allowed for this correlation to be extended over the majority of on-therapy drug concentrations. PMID:26842561

  13. Lyso-Sulfatide Binds Factor Xa and Inhibits Thrombin Generation by the Prothrombinase Complex.

    Directory of Open Access Journals (Sweden)

    Subramanian Yegneswaran

    Full Text Available Blood coagulation reactions are strongly influenced by phospholipids, but little is known about the influence of sphingolipids on coagulation mechanisms. Lysosulfatide (lyso-SF (sulfogalactosyl sphingosine prolonged factor Xa (fXa 1-stage plasma clotting assays, showing it had robust anticoagulant activity. In studies using purified clotting factors, lyso-SF inhibited >90% of prothrombin (II activation for reaction mixtures containing fXa/factor Va (fVa/II, and also inhibited II activation generation by fXa/ phospholipids and by Gla-domainless-fXa/fVa/phospholipids. When lyso-SF analogs were tested, results showed that N-acetyl-sulfatide was not anticoagulant, implying that the free amine group was essential for the anticoagulant effects of lyso-SF. Lyso-SF did not inhibit fXa enzymatic hydrolysis of small peptide substrates, showing it did not directly inhibit the fXa activity. In surface plasmon resonance studies, lyso-SF bound to immobilized inactivated fXa as well as inactivated Gla-domainless-fXa. Confirming this lyso-SF:fXa interaction, fluorescence studies showed that fluorescently-labeled-fXa in solution bound to lyso-SF. Thus, lyso-SF is an anticoagulant lipid that inhibits fXa when this enzyme is bound to either phospholipids or to fVa. Mechanisms for inhibition of procoagulant activity are likely to involve lyso-SF binding to fXa domain(s that are distinct from the fXa Gla domain. This suggests that certain sphingolipids, including lyso-SF and some of its analogs, may down-regulate fXa activity without inhibiting the enzyme's active site or binding to the fXa Gla domain.

  14. Superfund Record of Decision (EPA Region 2): Kin-Buc Landfill, Edison Township, Middlesex County, NJ. (Second remedial action), September 1992. Final report

    International Nuclear Information System (INIS)

    The 200-acre Kin-Buc Landfill consists of several inactive disposal areas and is located in Edison Township, Middlesex County, New Jersey. Land use in the area is predominantly industrial and commercial, with some residences within 2 miles north of the site. No drinking water supply wells are located within a 2-mile radius of the site. As a result of an oil spill in 1976, EPA conducted an investigation of the property. In 1980, clean-up activities were initiated under the Clean Water Act and included removal, treatment, and disposal of leachate and drummed waste. The ROD addresses a final remedy for OU2 consisting of the sediment and groundwater in the Edmonds Creek wetlands area, Mill Brook/Martins Creek, Mound B, and the low-lying area. The primary contaminants of concern affecting the sediment and ground water are VOCs, including benzene and xylenes; other organics, including PAHs, PCBs, and pesticides; and metals, including arsenic and lead. The selected remedy for the site are included

  15. Kinetic characterization of factor Xa binding using a quenched fluorescent substrate based on the reactive site of factor Xa inhibitor from Bauhinia ungulata seeds.

    Science.gov (United States)

    Oliva, M L V; Andrade, S A; Juliano, M A; Sallai, R C; Torquato, R J; Sampaio, M U; Pott, V J; Sampaio, C A M

    2003-07-01

    The specific Kunitz Bauhinia ungulata factor Xa inhibitor (BuXI) and the Bauhinia variegata trypsin inhibitor (BvTI) blocked the activity of trypsin, chymotrypsin, plasmin, plasma kallikrein and factor XIIa, and factor Xa inhibition was achieved only by BuXI (K(i) 14 nM). BuXI and BvTI are highly homologous (70%). The major differences are the methionine residues at BuXI reactive site, which are involved in the inhibition, since the oxidized protein no longer inhibits factor Xa but maintains the trypsin inhibition. Quenched fluorescent substrates based on the reactive site sequence of the inhibitors were synthesized and the kinetic parameters of the hydrolysis were determined using factor Xa and trypsin. The catalytic efficiency k(cat)/K(m) 4.3 x 10(7) M(-1)sec(>-1) for Abz-VMIAALPRTMFIQ-EDDnp (lead peptide) hydrolysis by factor Xa was 10(4)-fold higher than that of Boc-Ile-Glu-Gly-Arg-AMC, widely used as factor Xa substrate. Lengthening of the substrate changed its susceptibility to factor Xa hydrolysis. Both methionine residues in the substrate influence the binding to factor Xa. Serine replacement of threonine (P(1)') decreases the catalytic efficiency by four orders of magnitude. Factor Xa did not hydrolyze the substrate containing the reactive site sequence of BvTI, that inhibits trypsin inhibitor but not factor Xa. Abz-VMIAALPRTMFIQ-EDDnp prolonged both the prothrombin time and the activated partial thromboplastin time, and the other modified substrates used in this experiment altered blood-clotting assays. PMID:12678803

  16. Effects of Water Soluble Phosphotidylserine on Bovine Factor Xa: Functional and Structural Changes Plus Dimerization

    OpenAIRE

    Majumder, Rinku; Wang, Jianfang; Lentz, Barry R.

    2003-01-01

    Previous work has shown that two molecules of a soluble form of phosphatidylserine, C6PS, bind to human and bovine factor Xa. Activity measurements along with the fluorescence of active-site-labeled human factor Xa showed that two linked sites specifically regulate the active site conformation and proteolytic activity of the human enzyme. These results imply, but cannot demonstrate, a C6PS-induced factor Xa conformational change. The purpose of this paper is to extend these observations to bo...

  17. Comparison of three different anti-Xa assays in major orthopedic surgery patients treated with fondaparinux.

    Science.gov (United States)

    Ikejiri, Makoto; Wada, Hideo; Yamaguchi, Toshio; Miyazaki, Shinichi; Hasegawa, Masahiro; Wakabayashi, Hiroki; Asanuma, Kunihiro; Sakaguchi, Akane; Matsumoto, Takeshi; Ohishi, Kohshi; Fujimoto, Naoki; Yamada, Norikazu; Ito, Masaaki; Katayama, Naoyuki; Sudo, Akihiro

    2016-05-01

    Anti-Xa assays are useful for monitoring the effects of selective anti-Xa drugs, such as fondaparinux, in the prophylaxis of deep vein thrombosis. In the present study, anti-Xa activity was measured using three different assays, Testzym(®) Heparin S, STA(®)-Liquid Anti-Xa and HemosIL(®) Liquid Heparin. Anti-Xa activity in each assay gradually increased from day one after administration to day eight, and still remained on day 15. Although there were significant differences in anti-Xa activity among the three assays, the activity showed significant correlation across assays. There were no significant differences in the anti-Xa activity between patients with and without DVT or between patients with and without massive bleeding on day one before and after administration, day four, day eight and day 15. Anti-Xa activity in each assay was weakly correlated with antithrombin (AT) activity. The AT activity in patients were significantly higher on days four, eight and 15 compared with day one before and after administration, suggesting that AT activity increases following the administration of fondaparinux. The three anti-Xa assay kits tested are useful for monitoring fondaparinux treatment in orthopedic surgery patients. PMID:26922193

  18. A comparative approach expands the protein-protein interaction node of the immune receptor XA21 in wheat and rice

    OpenAIRE

    Yang, Baoju; Ruan, Randy; Cantu, Dario; Wang, Xiaodong; Ji, Wanquan; Ronald, Pamela C; Dubcovsky, Jorge

    2013-01-01

    The rice (Oryza sativa) OsXA21 receptor kinase is a well-studied immune receptor that initiates a signal transduction pathway leading to resistance to Xanthomonas oryzae pv. oryzae. Two homologs of OsXA21 were identified in wheat (Triticum aestivum): TaXA21-like1 located in a syntenic region with OsXA21, and TaXA21-like2 located in a non-syntenic region. Proteins encoded by these two wheat genes interact with four wheat orthologs of known OsXA21 interactors. In this study, we screened a wheat...

  19. Evaluation of Factor Xa-Specific Chromogenic Substrate Assays and the Determination of Pharmacokinetics of Fondaparinux.

    Science.gov (United States)

    Yuri, Maiko; Tabe, Yoko; Tsuchiya, Koji; Sadatsuki, Ryo; Aoki, Jun; Horii, Takashi; Iba, Toshiaki; Ohsaka, Akimichi

    2016-07-01

    Fondaparinux (FPX), a synthesized factor Xa inhibitor, is one of the most popular anticoagulants for the prevention of postoperative venous thromboembolism (VTE). Although routine monitoring is not required, the bleeding adverse events cannot be neglected, and the measurement of anti-Xa activity is expected to be monitored. The primary purpose of this study is to evaluate the performances of 2 chromogenic assays for the detection of anti-Xa activity. Furthermore, the pharmacokinetics of FPX was examined using chromogenic assays. Anti-Xa activity was measured using 2 FPX-based chromogenic substrates (S2222 and STA-Liquid Anti-Xa). The reproducibility, detection limits, linearity, and correlations between the substrates were examined using normal plasma doped with low and high concentrations of FPX formulation. In addition, anti-Xa activity in 235 clinical samples from 164 cases treated was measured, and the pharmacokinetics of FPX was evaluated. Both of the tested substrates were capable of accurately measuring the anti-Xa activity of FPX, with a lower limit of 0.05 μg/mL and a coefficient of variation of less than 10%. The repeated administration of FPX induced a gradual but significant increase in the anti-Xa activity, which was negatively correlated with body weight and estimated glomerular filtration rate. No significant correlation between the anti-Xa activity and the occurrence of postoperative VTE or bleeding event was observed. Anti-Xa activity can be successfully determined using 2 chromogenic assays and automated biochemical analyzers. The clinical significance of anti-Xa activity monitoring should be examined in the future study. PMID:26177660

  20. Purification of a Ni sup 2+ -binding protein, pNiXa, from Xenopus ovary

    Energy Technology Data Exchange (ETDEWEB)

    Beck, B.L.; Makowski, G.S.; Nomoto, S.; Sunderman, F.W. (Univ. of Connecticut, Farmington (United States))

    1991-03-11

    Previous research on nickel-induced teratogenesis in Xenopus laevis identified several Ni{sup 2+}-binding proteins, including pNiXa in Xenopus ovaries, unfertilized eggs, and embryos. A major goal of this research project is elucidating the role of pNiXa in the uptake, embryotoxicity, and teratogenicity of Ni{sup 2+} in Xenopus. To purify and identify pNiXa, ovarian tissue from mature Xenopus females was homogenized in 3 vol of Tris buffer and centrifuged. The supernatant was centrifuged; the ultracentrifugal supernatant was batch-adsorbed onto DEAE-cellulose. The pNiSa remained unbound and was subsequently adsorbed on phosphocellulose and eluted by a step-wise NaCl gradient. The pNiXa was eluted in 0.25 M NaCl; this fraction was concentrated, and further purified by reverse phase chromatography on a 5 {mu}m C-8 column, with a linear trifluoroacetic acid/acetonitrile gradient. The pNiXa was eluted at {approximately}56% acetonitrile, yielding a single protein band with mol wt {approximately}47 kD,based on SDS-PAGE analysis. Comparison of the amino acid composition of pNiXa versus the results obtained by automated Edman degradation indicated that the N-terminus of pNiXa was blocked. Sequencing of peptide fragments of pNiXa is underway.

  1. RIVAROXABAN: AN ORAL DIRECT INHIBITOR OF FACTOR X-A

    Directory of Open Access Journals (Sweden)

    Mehta Hiren R

    2011-08-01

    Full Text Available Venous thrombo embolism (VTE, which includes deep vein thrombosis and pulmonary embolism, is a major cause of morbidity and mortality in patients undergoing major orthopaedic surgery, and routine thrombo prophylaxis has been the standard of care over the last 20 years. Currently available options for the prevention of venous thrombo embolism in major orthopedic surgery include low-molecular-weight heparins, vitamin K antagonists and, more recently, the synthetic pentasaccharide fondaparinux. Although effective, these drugs have several limitations, and new oral antithrombotics offering predictable, effective and safe anticoagulation are strongly needed. This overview focuses on the most advanced oral direct inhibitors of factor Xa, rivaroxaban.Rivaroxaban, an oral oxazolidinone-based anticoagulant, is a potent, selective direct inhibitor of factor Xa that is used in the prevention of venous thrombo embolism in adult patients after total hip replacement (THR or total knee replacement (TKR surgery. In four large, clinical trials, oral rivaroxaban was more effective than subcutaneous enoxaparin in preventing postoperative VTE in patients undergoing total hip replacement or total knee replacement surgery. Notably, the superior efficacy of rivaroxaban was achieved with a low but not significant increase in the incidence of major bleeding episodes. In addition, preliminary pharma co-economic analyses in several countries indicate that rivaroxaban is a cost-effective treatment strategy versus enoxaparin. Although the position of rivaroxaban relative to other therapies remains to be fully determined, it is an effective emerging option for the prevention of venous thrombo embolism following total hip replacement and total knee replacement.

  2. Fast rotation of a subkilometer-sized near-Earth object 2011 XA{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Urakawa, Seitaro [Bisei Spaceguard Center, Japan Spaceguard Association, 1716-3 Okura, Bisei, Ibara, Okayama 714-1411 (Japan); Ohtsuka, Katsuhito [Tokyo Meteor Network, 1-27-5 Daisawa, Setagaya-ku, Tokyo 155-0032 (Japan); Abe, Shinsuke [Department of Aerospace Engineering, College of Science and Technology, Nihon University, 7-24-1 Narashinodai, Funabashi, Chiba 274-8501 (Japan); Ito, Takashi [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Nakamura, Tomoki, E-mail: urakawa@spaceguard.or.jp [Department of Earth and Planetary Material Sciences, Graduate School of Science, Tohoku University, Aoba, Sendai, Miyagi 980-8578 (Japan)

    2014-05-01

    We present light curve observations and their multiband photometry for near-Earth object (NEO) 2011 XA{sub 3}. The light curve has shown a periodicity of 0.0304 ± 0.0003 days (= 43.8 ± 0.4 minutes). The fast rotation shows that 2011 XA{sub 3} is in a state of tension (i.e., a monolithic asteroid) and cannot be held together by self-gravitation. Moreover, the multiband photometric analysis indicates that the taxonomic class of 2011 XA{sub 3} is S-complex, or V-type. Its estimated effective diameter is 225 ± 97 m (S-complex) and 166 ± 63 m (V-type), respectively. Therefore, 2011 XA{sub 3} is a candidate for the second-largest, fast-rotating, monolithic asteroid. Moreover, the orbital parameters of 2011 XA{sub 3} are apparently similar to those of NEO (3200) Phaethon, but F/B-type. We computed the orbital evolutions of 2011 XA{sub 3} and Phaethon. However, the results of the computation and distinct taxonomy indicate that neither of the asteroids is of common origin.

  3. Fast rotation of a subkilometer-sized near-Earth object 2011 XA3

    International Nuclear Information System (INIS)

    We present light curve observations and their multiband photometry for near-Earth object (NEO) 2011 XA3. The light curve has shown a periodicity of 0.0304 ± 0.0003 days (= 43.8 ± 0.4 minutes). The fast rotation shows that 2011 XA3 is in a state of tension (i.e., a monolithic asteroid) and cannot be held together by self-gravitation. Moreover, the multiband photometric analysis indicates that the taxonomic class of 2011 XA3 is S-complex, or V-type. Its estimated effective diameter is 225 ± 97 m (S-complex) and 166 ± 63 m (V-type), respectively. Therefore, 2011 XA3 is a candidate for the second-largest, fast-rotating, monolithic asteroid. Moreover, the orbital parameters of 2011 XA3 are apparently similar to those of NEO (3200) Phaethon, but F/B-type. We computed the orbital evolutions of 2011 XA3 and Phaethon. However, the results of the computation and distinct taxonomy indicate that neither of the asteroids is of common origin.

  4. 3D/3D registration of coronary CTA and biplane XA reconstructions for improved image guidance

    Energy Technology Data Exchange (ETDEWEB)

    Dibildox, Gerardo, E-mail: g.dibildox@erasmusmc.nl; Baka, Nora; Walsum, Theo van [Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus Medical Center, 3015 GE Rotterdam (Netherlands); Punt, Mark; Aben, Jean-Paul [Pie Medical Imaging, 6227 AJ Maastricht (Netherlands); Schultz, Carl [Department of Cardiology, Erasmus Medical Center, 3015 GE Rotterdam (Netherlands); Niessen, Wiro [Quantitative Imaging Group, Faculty of Applied Sciences, Delft University of Technology, 2628 CJ Delft, The Netherlands and Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus Medical Center, 3015 GE Rotterdam (Netherlands)

    2014-09-15

    Purpose: The authors aim to improve image guidance during percutaneous coronary interventions of chronic total occlusions (CTO) by providing information obtained from computed tomography angiography (CTA) to the cardiac interventionist. To this end, the authors investigate a method to register a 3D CTA model to biplane reconstructions. Methods: The authors developed a method for registering preoperative coronary CTA with intraoperative biplane x-ray angiography (XA) images via 3D models of the coronary arteries. The models are extracted from the CTA and biplane XA images, and are temporally aligned based on CTA reconstruction phase and XA ECG signals. Rigid spatial alignment is achieved with a robust probabilistic point set registration approach using Gaussian mixture models (GMMs). This approach is extended by including orientation in the Gaussian mixtures and by weighting bifurcation points. The method is evaluated on retrospectively acquired coronary CTA datasets of 23 CTO patients for which biplane XA images are available. Results: The Gaussian mixture model approach achieved a median registration accuracy of 1.7 mm. The extended GMM approach including orientation was not significantly different (P > 0.1) but did improve robustness with regards to the initialization of the 3D models. Conclusions: The authors demonstrated that the GMM approach can effectively be applied to register CTA to biplane XA images for the purpose of improving image guidance in percutaneous coronary interventions.

  5. The Matrix Equation XA- AX=Xαg(X over Fields or Rings

    Directory of Open Access Journals (Sweden)

    Gerald Bourgeois

    2014-01-01

    Full Text Available Let n,α∈N≥2 and let K be an algebraically closed field with characteristic 0 or greater than n. We show that if f∈K[X] and A,B∈Mn(K satisfy [A,B]=f(A, then A,B are simultaneously triangularizable. Let R be a reduced ring such that n! is not a zero divisor and let A be a generic matrix over R; we show that X=0 is the sole solution of AX-XA=Xα. Let R be a commutative ring with unity; let A be similar to diag(λ1In1,…,λrInr such that, for every i≠j,λi-λj is not a zero divisor. If X is a nilpotent solution of XA-AX=Xαg(X where g∈R[X], then AX=XA.

  6. On Diophantine Equations of the Form $(x-a_1)(x-a_2)\\ldots(x-a_k)+r=y^n$

    Indian Academy of Sciences (India)

    Manisha Kulkarni; B Sury

    2011-08-01

    Erdős and Selfridge [3] proved that a product of consecutive integers can never be a perfect power. That is, the equation $x(x+1)(x+2)\\ldots(x+(m-1))=y^n$ has no solutions in positive integers $x,m,n$ where $m,n>1$ and $y\\in Q$. We consider the equation $$(x-a_1)(x-a_2)\\ldots(x-a_k)+r=y^n$$ where $0≤ a_1 < a_2 <\\cdots < a_k$ are integers and, with $r\\in Q,n≥ 3$ and we prove a finiteness theorem for the number of solutions in $Z,y$ in . Following that, we show that, more interestingly, for every nonzero integer >2 and for any nonzero integer which is not a perfect -th power for which the equation admits solutions, is bounded by an effective bound.

  7. "XA6" octahedra influencing the arrangement of anionic groups and optical properties in inverse-perovskite [B6O10]XA3 (X = Cl, Br; A = alkali metal).

    Science.gov (United States)

    Yang, Zhihua; Lei, Bing-Hua; Yang, Bin; Pan, Shilie

    2016-06-01

    Exploring the effect of microscopic units, which set up the perovsikte framework, is of importance for material design. In this study, a series of borate halides with inverse-perovskite structures [B6O10]XA3 (X = Cl, Br; A = alkali metal) have been studied. It was revealed that the distortion and volume of XA6 octahedra influence the arrangement of anionic groups, which leads to the flexibility of the perovskite-related framework and differences in optical properties. Under the structural control scheme, the structure of Rb3B6O10Cl was predicted. The stability of the predicted structure was confirmed by an ab initio density functional theory-based method. The calculation shows Rb3B6O10Cl has a short UV cutoff edge of less than 200 nm, a moderate birefringence and a large second harmonic generation response. PMID:27211304

  8. Introduction of a rice blight resistance gene, Xa21, into five Chinese rice varieties through an Agrobacterium-mediated system

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A cloned gene, Xa21 was transferred into five widely-used Chinese rice varieties through an Agrobacterium-mediated system, and over 110 independent transgenic lines were obtained. PCR and Southern analysis of transgenic plants revealed the integration of the whole Xa21 gene into the host genomes. The integrated Xa21 gene was stably inherited, and segregated in a 3∶1 ratio in the selfed T1 generation when one copy of the gene was integrated in the transformants. Inoculation tests displayed that transgenic T0 plants and Xa21 PCR-positive T1 plants were highly resistant to bacterial blight disease. The selected Xa21 homozygous resistant transgenic lines with desirable qualities may be propagated as new varieties or utilized in hybrid rice breeding.

  9. Pleiotropic effects of factor Xa and thrombin : what to expect from novel anticoagulants

    NARCIS (Netherlands)

    Spronk, Henri M. H.; de Jong, Anne Margreet; Crijns, Harry J.; Schotten, Ulrich; Van Gelder, Isabelle C.; ten Cate, Hugo

    2014-01-01

    Factor Xa and thrombin are well-known components of the coagulation cascade and have been proven to be viable targets for effective anticoagulation treatment. However, accumulating evidence suggests that these serine proteases are also crucial modulators of other cellular mechanisms through the acti

  10. The role of structural information in the discovery of direct thrombin and factor Xa inhibitors.

    Science.gov (United States)

    Nar, Herbert

    2012-05-01

    The quest for novel medications to treat thromboembolic disorders such as venous thrombosis, pulmonary embolism and stroke received a boost when the 3D structures of two major players in the blood coagulation cascade were determined in 1989 and 1993. Structure-guided design of inhibitors of thrombin (factor IIa, fIIa) and factor Xa (fXa) eventually led to the discovery of potent, selective, efficacious, orally active and safe compounds that proved successful in clinical studies. In 2008, the direct thrombin inhibitor dabigatran etexilate developed by Boehringer Ingelheim became the first novel antithrombotic molecular entity to enter the market in 50 years. Additional compounds targeting factor Xa were subsequently granted marketing authorization or are in late-stage clinical studies. In this review, I use selected case studies to describe the discovery of novel fIIa and fXa inhibitors, with a particular emphasis on the pre-eminent role that structural information played in this process. PMID:22503439

  11. Factor Xa generation by computational modeling: an additional discriminator to thrombin generation evaluation.

    Directory of Open Access Journals (Sweden)

    Kathleen E Brummel-Ziedins

    Full Text Available Factor (fXa is a critical enzyme in blood coagulation that is responsible for the initiation and propagation of thrombin generation. Previously we have shown that analysis of computationally generated thrombin profiles is a tool to investigate hemostasis in various populations. In this study, we evaluate the potential of computationally derived time courses of fXa generation as another approach for investigating thrombotic risk. Utilizing the case (n = 473 and control (n = 426 population from the Leiden Thrombophilia Study and each individual's plasma protein factor composition for fII, fV, fVII, fVIII, fIX, fX, antithrombin and tissue factor pathway inhibitor, tissue factor-initiated total active fXa generation was assessed using a mathematical model. FXa generation was evaluated by the area under the curve (AUC, the maximum rate (MaxR and level (MaxL and the time to reach these, TMaxR and TMaxL, respectively. FXa generation was analyzed in the entire populations and in defined subgroups (by sex, age, body mass index, oral contraceptive use. The maximum rates and levels of fXa generation occur over a 10- to 12- fold range in both cases and controls. This variation is larger than that observed with thrombin (3-6 fold in the same population. The greatest risk association was obtained using either MaxR or MaxL of fXa generation; with an ∼2.2 fold increased risk for individuals exceeding the 90(th percentile. This risk was similar to that of thrombin generation(MaxR OR 2.6. Grouping defined by oral contraceptive (OC use in the control population showed the biggest differences in fXa generation; a >60% increase in the MaxR upon OC use. FXa generation can distinguish between a subset of individuals characterized by overlapping thrombin generation profiles. Analysis of fXa generation is a phenotypic characteristic which may prove to be a more sensitive discriminator than thrombin generation among all individuals.

  12. Binding of human factors X and Xa to HepG2 and J82 human tumor cell lines. Evidence that factor Xa binds to tumor cells independent of factor Va

    International Nuclear Information System (INIS)

    Previous studies demonstrated that several cultured human tumor cell lines potentiate the conversion of prothrombin to thrombin by factor Xa and calcium in the absence of exogenous factor Va. In the present study, the specific binding of radioiodinated preparations of human factor X and factor Xa to a human hepatocellular carcinoma cell line (HepG2) that constitutively synthesizes a factor V/Va molecule, and a human bladder carcinoma cell line (J82) that does not synthesize factor V/Va, was examined. Radioiodinated factor Xa bound specifically to J82 and HepG2 cells, whereas no significant specific binding of 125I-factor X to either cell was observed. The binding isotherm of 125I-factor Xa to each tumor cell line exhibited a hyperbolic profile, and Scatchard analysis demonstrated a single class of binding site for factor Xa on each cell surface with Kd values of 1.66 +/- 0.39 and 1.64 +/- 0.52 nM and 566,000 +/- 71,000 and 28,000 +/- 6,000 binding sites/cell for HepG2 and J82 cells, respectively. Thrombin formation by cell-bound factor Xa was hyperbolic and saturable at 5 nM factor Xa on each cell line. Hanes-Woolf plots of the prothrombin activation data indicated that half-maximal rates of thrombin formation occurred at factor Xa concentrations of 1.50 +/- 0.43 nM and 1.42 +/- 0.48 nM on HepG2 and J82 cells, respectively. Pretreatment of J82 cells with polyclonal anti-human factor V IgG had no measurable effect on either the binding of 125I-factor Xa or prothrombin activation. However, pretreatment of HepG2 cells with anti-human factor V IgG inhibited prothrombin activation in a dose-dependent manner, but did not inhibit the binding of factor Xa to this cell. When both cell lines were preincubated with exogenous human factor Va, the binding of factor Xa to either HepG2 or J82 cells was marginally affected

  13. Inhibition of thrombin and factor Xa by Fucus evanescens fucoidan and its modified analogs.

    Science.gov (United States)

    Lapikova, E S; Drozd, N N; Tolstenkov, A S; Makarov, V A; Zvyagintseva, T N; Shevchenko, N M; Bakunina, I U; Besednova, N N; Kuznetsova, T A

    2008-09-01

    Specimens of fucoidan extracted from Fucus evanescens were purified from protein and polyphenols, deacetylated and depolymerized by fucoidanase for evaluation of their biological activity. Deacetylation did not modify the capacity of fucoidan to inhibit thrombin and factor Xa, while purification from protein and polyphenols reduced this capacity. Depolymerization of fucoidan increased its capacity to inhibit thrombin mainly through heparin cofactor II. All the studied specimens formed complexes with protamine sulfate. PMID:19240852

  14. Role of Factor Xa Inhibitors in Cancer-Associated Thrombosis: Any New Data?

    OpenAIRE

    Carmen Escalante; Syed Wamique Yusuf; Vahid Afshar-Kharghan; Ali Zalpour; Kroll, Michael H.

    2011-01-01

    The association between cancer and venous thromboembolism (VTE) has been well documented in the literature. Prevention and treatment of VTE in cancer patients is imperative. Typically, the mainstay regimen for VTE prevention and treatment has been anticoagulation therapy, unless contraindicated. This therapy consists of unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), factor Xa inhibitor, or vitamin K antagonist (VKA). Current guidelines recommend LMWH over VKA for the treat...

  15. Comparative nutritional compositions and proteomics analysis of transgenic Xa21 rice seeds compared to conventional rice.

    Science.gov (United States)

    Gayen, Dipak; Paul, Soumitra; Sarkar, Sailendra Nath; Datta, Swapan K; Datta, Karabi

    2016-07-15

    Transgenic rice expressing the Xa21 gene have enhanced resistant to most devastating bacterial blight diseases caused by Xanthomonas oryzae pv. oryzae (Xoo). However, identification of unintended modifications, owing to the genetic modification, is an important aspect of transgenic crop safety assessment. In this study, the nutritional compositions of seeds from transgenic rice plants expressing the Xa21 gene were compared against non-transgenic rice seeds. In addition, to detect any changes in protein translation levels as a result of Xa21 gene expression, rice seed proteome analyses were also performed by two-dimensional gel electrophoresis. No significant differences were found in the nutritional compositions (proximate components, amino acids, minerals, vitamins and anti-nutrients) of the transgenic and non-transgenic rice seeds. Although gel electrophoresis identified 11 proteins that were differentially expressed between the transgenic and non-transgenic seed, only one of these (with a 20-fold up-regulation in the transgenic seed) shows nutrient reservoir activity. No new toxins or allergens were detected in the transgenic seeds. PMID:26948618

  16. The phylogenetically-related pattern recognition receptors EFR and XA21 recruit similar immune signaling components in monocots and dicots.

    Directory of Open Access Journals (Sweden)

    Nicholas Holton

    2015-01-01

    Full Text Available During plant immunity, surface-localized pattern recognition receptors (PRRs recognize pathogen-associated molecular patterns (PAMPs. The transfer of PRRs between plant species is a promising strategy for engineering broad-spectrum disease resistance. Thus, there is a great interest in understanding the mechanisms of PRR-mediated resistance across different plant species. Two well-characterized plant PRRs are the leucine-rich repeat receptor kinases (LRR-RKs EFR and XA21 from Arabidopsis thaliana (Arabidopsis and rice, respectively. Interestingly, despite being evolutionary distant, EFR and XA21 are phylogenetically closely related and are both members of the sub-family XII of LRR-RKs that contains numerous potential PRRs. Here, we compared the ability of these related PRRs to engage immune signaling across the monocots-dicots taxonomic divide. Using chimera between Arabidopsis EFR and rice XA21, we show that the kinase domain of the rice XA21 is functional in triggering elf18-induced signaling and quantitative immunity to the bacteria Pseudomonas syringae pv. tomato (Pto DC3000 and Agrobacterium tumefaciens in Arabidopsis. Furthermore, the EFR:XA21 chimera associates dynamically in a ligand-dependent manner with known components of the EFR complex. Conversely, EFR associates with Arabidopsis orthologues of rice XA21-interacting proteins, which appear to be involved in EFR-mediated signaling and immunity in Arabidopsis. Our work indicates the overall functional conservation of immune components acting downstream of distinct LRR-RK-type PRRs between monocots and dicots.

  17. Fine mapping of the rice bacterial blight resistance gene Xa-4 and its co-segregation marker

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An F2 population developed from the Xa-4 near isogenic lines,IR24 and IRBB4,was used for fine mapping of the rice bacterial blight resistance gene,Xa-4.Some restriction fragment length polymorphism (RFLP) markers on the high-density map constructed by Harushima et al.and the amplified DNA fragments homologous to the conserved domains of plant disease resistance (R) genes were used to construct the genetic linkage map around the gene Xa-4 by scoring susceptible individuals in the population.Xa-4 was mapped between the RFLP marker G181 and the polymerase chain reaction (PCR) marker M55.The R gene homologous fragment marker RS13 was found co-segregating with Xa-4 by analyzing all the plants in the population.This result opened an approach to map-based cloning of this gene,and marker RS13 can be applied to molecular marker-assisted selection of Xa-4 in rice breeding programs.

  18. Structure-based drug design of pyrrolidine-1, 2-dicarboxamides as a novel series of orally bioavailable factor Xa inhibitors.

    Science.gov (United States)

    Van Huis, Chad A; Bigge, Christopher F; Casimiro-Garcia, Agustin; Cody, Wayne L; Dudley, Danette A; Filipski, Kevin J; Heemstra, Ronald J; Kohrt, Jeffrey T; Narasimhan, Lakshmi S; Schaum, Robert P; Zhang, Erli; Bryant, John W; Haarer, Staci; Janiczek, Nancy; Leadley, Robert J; McClanahan, Thomas; Thomas Peterson, J; Welch, Kathleen M; Edmunds, Jeremy J

    2007-06-01

    A novel series of pyrrolidine-1,2-dicarboxamides was discovered as factor Xa inhibitors using structure-based drug design. This series consisted of a neutral 4-chlorophenylurea P1, a biphenylsulfonamide P4 and a D-proline scaffold (1, IC(50) = 18 nM). Optimization of the initial hit resulted in an orally bioavailable, subnanomolar inhibitor of factor Xa (13, IC(50) = 0.38 nM), which was shown to be efficacious in a canine electrolytic model of thrombosis with minimal bleeding. PMID:17581239

  19. Identification and gene prediction of a 24 kb region containing xa5, a recessive bacterial blight resistance gene in rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    ZHONG Yiming; JIANG Guanghuai; CHEN Xuewei; XIA Zhihui; LI Xiaobing; ZHU Lihuang; ZHAI Wenxue

    2003-01-01

    Rice xa5 gene provides recessive, race-specific resistance to bacterial blight disease caused by the pathogen Xanthomonas oryzae pv. oryzae and has great value for research and breeding. In an effort to clone xa5, an F2 population of 4892 individuals was developed from the xa5 near isogenic lines, IR24 and IRBB5. A fine mapping procedure was conducted and tightly linked RFLP markers were used to screen a BAC library of IRBB56, a resistant rice line containing the xa5 gene. A 213 kb contig covering the xa5 locus was constructed. According to the sequences from the International Rice Genome Sequening Project (IRGSP), the Chinese Superhybrid Rice Genome Project (SRGP) and some sub-clones of the contig, twelve SSLP and CAPS markers were developed for fine mapping. The xa5 gene was mapped to a 0.3 cM interval between markers K5 and T4, which spanned an interval of approximately 24 kb, co-segregating with marker T2. Sequence analysis of the 24 kb region revealed that an ABC transporter and a basal transcription factor (TFIIa) were potential candidates for the xa5 resistance gene product. The molecular mechanism by which the xa5 gene provides recessive, race-specific resistance to bacterial blight will be elucidated by the functional tests of the 24 kb DNA and the candidate genes.

  20. Basis for the Specificity and Activation of the Serpin Protein Z-dependent Proteinase Inhibitor (ZPI) as an Inhibitor of Membrane-associated Factor Xa

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xin; Dementiev, Alexey; Olson, Steven T.; Gettins, Peter G.W. (UIC)

    2012-12-13

    The serpin ZPI is a protein Z (PZ)-dependent specific inhibitor of membrane-associated factor Xa (fXa) despite having an unfavorable P1 Tyr. PZ accelerates the inhibition reaction {approx}2000-fold in the presence of phospholipid and Ca{sup 2+}. To elucidate the role of PZ, we determined the x-ray structure of Gla-domainless PZ (PZ{sub {Delta}GD}) complexed with protein Z-dependent proteinase inhibitor (ZPI). The PZ pseudocatalytic domain bound ZPI at a novel site through ionic and polar interactions. Mutation of four ZPI contact residues eliminated PZ binding and membrane-dependent PZ acceleration of fXa inhibition. Modeling of the ternary Michaelis complex implicated ZPI residues Glu-313 and Glu-383 in fXa binding. Mutagenesis established that only Glu-313 is important, contributing {approx}5-10-fold to rate acceleration of fXa and fXIa inhibition. Limited conformational change in ZPI resulted from PZ binding, which contributed only {approx}2-fold to rate enhancement. Instead, template bridging from membrane association, together with previously demonstrated interaction of the fXa and ZPI Gla domains, resulted in an additional {approx}1000-fold rate enhancement. To understand why ZPI has P1 tyrosine, we examined a P1 Arg variant. This reacted at a diffusion-limited rate with fXa, even without PZ, and predominantly as substrate, reflecting both rapid acylation and deacylation. P1 tyrosine thus ensures that reaction with fXa or most other arginine-specific proteinases is insignificant unless PZ binds and localizes ZPI and fXa on the membrane, where the combined effects of Gla-Gla interaction, template bridging, and interaction of fXa with Glu-313 overcome the unfavorability of P1 Tyr and ensure a high rate of reaction as an inhibitor.

  1. Effect of famotidine on the pharmacokinetics of apixaban, an oral direct factor Xa inhibitor

    Directory of Open Access Journals (Sweden)

    Upreti VV

    2013-04-01

    Full Text Available Vijay V Upreti,1 Yan Song,1 Jessie Wang,2 Wonkyung Byon,3 Rebecca A Boyd,3 Janice M Pursley,4 Frank LaCreta,1 Charles E Frost1 1Clinical Pharmacology and Pharmacometrics, Discovery Medicine and Clinical Pharmacology, 2Exploratory Development Global Biometric Sciences, Bristol-Myers Squibb, Princeton, NJ, 3Primary Care Clinical Pharmacology, Pfizer, Groton, CT, 4Analytical and Bioanalytical Department, Bristol-Myers Squibb, Princeton, NJ, USA Background: Apixaban is an oral, selective, direct factor Xa inhibitor approved for thromboprophylaxis after orthopedic surgery and stroke prevention in patients with atrial fibrillation, and under development for treatment of venous thromboembolism. This study investigated the effect of a gastric acid suppressant, famotidine (a histamine H2-receptor antagonist, on the pharmacokinetics of apixaban in healthy subjects. Methods: This two-period, two-treatment crossover study randomized 18 healthy subjects to receive a single oral dose of apixaban 10 mg with and without a single oral dose of famotidine 40 mg administered 3 hours before dosing with apixaban. Plasma apixaban concentrations were measured up to 60 hours post-dose and pharmacokinetic parameters were calculated. Results: Famotidine did not affect maximum apixaban plasma concentration (Cmax or area under the plasma concentration-time curve from zero to infinite time (AUC∞. Point estimates for ratios of geometric means with and without famotidine were close to unity for Cmax (0.978 and AUC∞ (1.007, and 90% confidence intervals were entirely contained within the 80%–125% no-effect interval. Administration of apixaban alone and with famotidine was well tolerated. Conclusion: Famotidine does not affect the pharmacokinetics of apixaban, consistent with the physicochemical properties of apixaban (lack of an ionizable group and pH-independent solubility. Apixaban pharmacokinetics would not be affected by an increase in gastrointestinal pH due to

  2. 争奇斗艳——丰田改装车Scion xA speedster

    Institute of Scientific and Technical Information of China (English)

    志华

    2006-01-01

    世界上的车展纷繁众多,有个叫SEMA的车展每年固定在赌城拉斯维加斯举行,车展的主题就是一个字:“怪”!丰田的这款Scion xA speedster就是其中之一小怪车。

  3. Spitzer IRS Observations of the XA Region in the Cygnus Loop Supernova Remnant

    CERN Document Server

    Sankrit, R; Bautista, M; Gaetz, T J; Williams, B J; Blair, W P; Borkowski, K J; Long, K S

    2014-01-01

    We report on spectra of two positions in the XA region of the Cygnus Loop supernova remnant obtained with the InfraRed Spectrograph on the Spitzer Space Telescope. The spectra span the 10-35 micron wavelength range, which contains a number of collisionally excited forbidden lines. These data are supplemented by optical spectra obtained at the Whipple Observatory and an archival UV spectrum from the International Ultraviolet Explorer. Coverage from the UV through the IR provides tests of shock wave models and tight constraints on model parameters. Only lines from high ionization species are detected in the spectrum of a filament on the edge of the remnant. The filament traces a 180 km/s shock that has just begun to cool, and the oxygen to neon abundance ratio lies in the normal range found for Galactic H II regions. Lines from both high and low ionization species are detected in the spectrum of the cusp of a shock-cloud interaction, which lies within the remnant boundary. The spectrum of the cusp region is mat...

  4. Contemporary developments in the discovery of selective factor Xa inhibitors: A review.

    Science.gov (United States)

    Patel, Nirav R; Patel, Dushyant V; Murumkar, Prashant R; Yadav, Mange Ram

    2016-10-01

    Thrombosis is a leading cause of death in cardiovascular diseases such as myocardial infarction (MI), unstable angina and acute coronary syndrome (ACS) in the industrialized world. Venous thromboembolism is observed in about 1 million people every year in United States causing significant morbidity and mortality. Conventional antithrombotic therapy has been reported to have several disadvantages and limitations like inconvenience in oral administration, bleeding risks (heparin analogs), narrow therapeutic window and undesirable interactions with food and drugs (vitamin K antagonist-warfarin). The unmet medical demand for orally active safe anticoagulants has generated widespread interest among the medicinal chemists engaged in this field. To modulate blood coagulation, various enzymes involved in the coagulation process have received great attention as potential targets by various research groups for the development of oral anticoagulants. Among these enzymes, factor Xa (FXa) has remained the centre of attention in the last decade. Intensive research efforts have been made by various research groups for the development of small, safe and orally bioavailable FXa inhibitors. This review is an attempt to compile the research work of various researchers in the direction of development of FXa inhibitors reported since 2010 onward. PMID:27322757

  5. Engineering Factor Xa Inhibitor with Multiple Platelet-Binding Sites Facilitates its Platelet Targeting

    Science.gov (United States)

    Zhu, Yuanjun; Li, Ruyi; Lin, Yuan; Shui, Mengyang; Liu, Xiaoyan; Chen, Huan; Wang, Yinye

    2016-01-01

    Targeted delivery of antithrombotic drugs centralizes the effects in the thrombosis site and reduces the hemorrhage side effects in uninjured vessels. We have recently reported that the platelet-targeting factor Xa (FXa) inhibitors, constructed by engineering one Arg-Gly-Asp (RGD) motif into Ancylostoma caninum anticoagulant peptide 5 (AcAP5), can reduce the risk of systemic bleeding than non-targeted AcAP5 in mouse arterial injury model. Increasing the number of platelet-binding sites of FXa inhibitors may facilitate their adhesion to activated platelets, and further lower the bleeding risks. For this purpose, we introduced three RGD motifs into AcAP5 to generate a variant NR4 containing three platelet-binding sites. NR4 reserved its inherent anti-FXa activity. Protein-protein docking showed that all three RGD motifs were capable of binding to platelet receptor αIIbβ3. Molecular dynamics simulation demonstrated that NR4 has more opportunities to interact with αIIbβ3 than single-RGD-containing NR3. Flow cytometry analysis and rat arterial thrombosis model further confirmed that NR4 possesses enhanced platelet targeting activity. Moreover, NR4-treated mice showed a trend toward less tail bleeding time than NR3-treated mice in carotid artery endothelium injury model. Therefore, our data suggest that engineering multiple binding sites in one recombinant protein is a useful tool to improve its platelet-targeting efficiency. PMID:27432161

  6. Engineering Factor Xa Inhibitor with Multiple Platelet-Binding Sites Facilitates its Platelet Targeting.

    Science.gov (United States)

    Zhu, Yuanjun; Li, Ruyi; Lin, Yuan; Shui, Mengyang; Liu, Xiaoyan; Chen, Huan; Wang, Yinye

    2016-01-01

    Targeted delivery of antithrombotic drugs centralizes the effects in the thrombosis site and reduces the hemorrhage side effects in uninjured vessels. We have recently reported that the platelet-targeting factor Xa (FXa) inhibitors, constructed by engineering one Arg-Gly-Asp (RGD) motif into Ancylostoma caninum anticoagulant peptide 5 (AcAP5), can reduce the risk of systemic bleeding than non-targeted AcAP5 in mouse arterial injury model. Increasing the number of platelet-binding sites of FXa inhibitors may facilitate their adhesion to activated platelets, and further lower the bleeding risks. For this purpose, we introduced three RGD motifs into AcAP5 to generate a variant NR4 containing three platelet-binding sites. NR4 reserved its inherent anti-FXa activity. Protein-protein docking showed that all three RGD motifs were capable of binding to platelet receptor αIIbβ3. Molecular dynamics simulation demonstrated that NR4 has more opportunities to interact with αIIbβ3 than single-RGD-containing NR3. Flow cytometry analysis and rat arterial thrombosis model further confirmed that NR4 possesses enhanced platelet targeting activity. Moreover, NR4-treated mice showed a trend toward less tail bleeding time than NR3-treated mice in carotid artery endothelium injury model. Therefore, our data suggest that engineering multiple binding sites in one recombinant protein is a useful tool to improve its platelet-targeting efficiency. PMID:27432161

  7. Characterization of Xanthomonas oryzae-Responsive cis-Acting Element in the Promoter of Rice Race-Specific Susceptibility Gene Xa13

    Institute of Scientific and Technical Information of China (English)

    Ting Yuan; Xianghua Li; Jinghua Xiao; Shiping Wang

    2011-01-01

    The rice Xa13 gene,whose promoter harbors a UPT (up-regulated by transcription activator-like [TAL] effector) box,UPTPthXo1,plays a pivotal role in the race-specific pathogenicity caused by Xanthomonas oryzae pv. Oryzae (Xoo) strain PXO99. PXO99 causes rice disease by inducing Xa13. It is unknown,however,whether the UPTPthXo1 box is the only PXO99-responsive c/s-regulating elements in the activation of Xa13 expression. We analyzed the expression of a series of end- and site-truncated and site-mutated Xa 13 promoters in rice and the binding of PXO99 protein to the intact,partial,or site-mutated UPTPthXo1 boxes. In the Xa13 promoter,UPTPthXo1 box is the only Xoo-responsive cis-acting element that results in PXO99-induced Xa13 expression. The 5'-terminal second,third,and fourth nucleotides of the box are important for bacterial protein binding and gene activation;mutation of any one of these sites abolished PXO99-induced gene expression. Furthermore,the 3'-half of the UPTPthXo1 box is also required for protein binding and gene activation. These findings will enhance our understanding of the molecular mechanism of the interaction of rice and Xoo via UPT boxes and TAL effectors.

  8. Spitzer IRS observations of the XA region in the cygnus loop supernova remnant

    Energy Technology Data Exchange (ETDEWEB)

    Sankrit, Ravi [SOFIA Science Center, NASA Ames Research Center, M/S N211-3, Moffett Field, CA 94035 (United States); Raymond, John C.; Gaetz, Terrance J. [Smithsonian Astrophysical Observatory, 60 Garden Street, MS 15, Cambridge, MA 02138 (United States); Bautista, Manuel [Department of Physics, Western Michigan University, Kalamazoo MI 49008-5252 (United States); Williams, Brian J. [Goddard Space Flight Center, Mail Code 662, Greenbelt, MD 20771 (United States); Blair, William P. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Borkowski, Kazimierz J. [North Carolina State University, Raleigh, NC 27607 (United States); Long, Knox S. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2014-05-20

    We report on spectra of two positions in the XA region of the Cygnus Loop supernova remnant obtained with the InfraRed Spectrograph on the Spitzer Space Telescope. The spectra span the 10-35 μm wavelength range, which contains a number of collisionally excited forbidden lines. These data are supplemented by optical spectra obtained at the Whipple Observatory and an archival UV spectrum from the International Ultraviolet Explorer. Coverage from the UV through the IR provides tests of shock wave models and tight constraints on model parameters. Only lines from high ionization species are detected in the spectrum of a filament on the edge of the remnant. The filament traces a 180 km s{sup –1} shock that has just begun to cool, and the oxygen to neon abundance ratio lies in the normal range found for Galactic H II regions. Lines from both high and low ionization species are detected in the spectrum of the cusp of a shock-cloud interaction, which lies within the remnant boundary. The spectrum of the cusp region is matched by a shock of about 150 km s{sup –1} that has cooled and begun to recombine. The post-shock region has a swept-up column density of about 1.3 × 10{sup 18} cm{sup –2}, and the gas has reached a temperature of 7000-8000 K. The spectrum of the Cusp indicates that roughly half of the refractory silicon and iron atoms have been liberated from the grains. Dust emission is not detected at either position.

  9. Structure-guided creation of AcAP5-derived and platelet targeted factor Xa inhibitors.

    Science.gov (United States)

    Zhu, Yuanjun; Lin, Yuan; Liu, Aihua; Shui, Mengyang; Li, Ruyi; Liu, Xiaoyan; Hu, Wenhui; Wang, Yinye

    2015-06-15

    Anticoagulants and anti-platelet agents are simultaneously administrated in clinical practice (i.e. percutaneous coronary intervention), which cause significant risk of systemic bleeding. Targeted delivery of anticoagulants to the activated platelets at sites of vascular injuries may condense the site-specific anticoagulant effect and reduce the hemorrhage side effects in uninjured vessels. To this end, we prepared three ancylostoma caninum anticoagulant peptide 5 (AcAP5) variants NR1, NR2 and NR3 engineered with a platelet-binding Arg-Gly-Asp (RGD) motif and evaluated their anti-Factor Xa (FXa) and platelet-binding effects. These RGD-containing AcAP5 variants were capable of interacting with platelet receptor αIIbβ3 as shown in computational analysis. All variants, especially NR2 and NR3, retained entirely the anti-FXa function of parent AcAP5. Moreover, they prevented the formation of occlusive thrombi in rat carotid artery injury model, suggesting that they inhibit platelet aggregation in vivo. Further functional investigation of NR3 demonstrated that NR3 inhibited platelet aggregation in vitro and FXa activity in vivo, and prolonged the coagulation time, all in a dose-dependent manner. Through flow cytometry assay, we confirmed the binding of NR3 to αIIbβ3 receptor. In mouse model of carotid artery endothelium injury, NR3-treated mice showed less tail bleeding time than AcAP5-treated mice, and aspirin plus NR3 treatment exhibited moderate reduction of blood loss compared with aspirin plus AcAP5 treatment. These results indicate the feasibility to engineer a novel FXa inhibitor specifically targeting the activated platelets, which centralizes its anticoagulation efficacy in the injured vascular endothelium and reduces the risk of systemic bleeding. PMID:25887920

  10. Coagulation factor Xa drives tumor cells into apoptosis through BH3-only protein Bim up-regulation

    International Nuclear Information System (INIS)

    Coagulation Factor (F)Xa is a serine protease that plays a crucial role during blood coagulation by converting prothrombin into active thrombin. Recently, however, it emerged that besides this role in coagulation, FXa induces intracellular signaling leading to different cellular effects. Here, we show that coagulation factor (F)Xa drives tumor cells of epithelial origin, but not endothelial cells or monocytes, into apoptosis, whereas it even enhances fibroblast survival. FXa signals through the protease activated receptor (PAR)-1 to activate extracellular-signal regulated kinase (ERK) 1/2 and p38. This activation is associated with phosphorylation of the transcription factor CREB, and in tumor cells with up-regulation of the BH3-only pro-apoptotic protein Bim, leading to caspase-3 cleavage, the main hallmark of apoptosis. Transfection of tumor cells with dominant negative forms of CREB or siRNA for either PAR-1, Bim, ERK1 and/or p38 inhibited the pro-apoptotic effect of FXa. In fibroblasts, FXa-induced PAR-1 activation leads to down-regulation of Bim and pre-treatment with PAR-1 or Bim siRNA abolishes proliferation. We thus provide evidence that beyond its role in blood coagulation, FXa plays a key role in cellular processes in which Bim is the central player in determining cell survival

  11. Oral IIa and Xa inhibitors for prevention of stroke in atrial fibrillation: clinical studies and regulatory considerations.

    Science.gov (United States)

    Deftereos, Spyridon; Tsounis, Dimitrios; Giannopoulos, Georgios; Kossyvakis, Charalampos; Panagopoulou, Vasiliki; Raisakis, Konstantinos; Stefanadis, Christodoulos

    2012-08-01

    Atrial fibrillation (AF), the most common, clinically significant, cardiac arrhythmia affects 1% of the general population and has important hemodynamic and thromboembolic complications that contribute to elevated morbidity and mortality. AF increases the overall risk of stroke five-fold, accounting for approximately 15% of all strokes and is associated with particularly severe stroke. For the last 50 years, long-term anticoagulation with vitamin K antagonists has been the most effective therapy for preventing stroke and systemic embolism in patients with AF and other risk factors, but their use has a lot of limitations and drawbacks (frequent monitoring and dose adjustment, food and drug interactions, delayed onset of action etc). Nowadays, new oral anticoagulants have emerged that seem to overcome those limitations. Direct thrombin inhibitor dabigatran and factor Xa inhibitors rivaroxaban and apixaban have proven, in large, multicenter, randomized, phase III, clinical studies, to be at least as efficient as warfarin in stroke prevention in patients with AF. RELY and ROCKET AF trials have contributed to market approval of dabigatran and rivaroxaban, respectively and made them available to clinical practice. Another factor Xa inhibitor, edoxaban, is under evaluation in an ongoing phase III clinical trial and others such as AZD0837, betrixaban and darexaban are still in safety and tolerability phase II studies. The oral anticoagulation landscape is changing rapidly and these new agents seem to be very promising. However future post-marketing studies and registries will help clarify their efficacy and safety. PMID:22564122

  12. AvrXa3:A novel member of avrBs3 gene family from Xanthomonas oryzae pv.oryzae has a dual function

    Institute of Scientific and Technical Information of China (English)

    LI Ping; LONG Juying; HUANG Yingchun; ZHANG Yan; WANG Jinsheng

    2004-01-01

    Two positive clones pUAV45 and pUAV47 were identified from the cDNA library of JxoⅢ, a race 3 strain of Xanthomonas oryzae pv. Oryzae Dye (Xoo) in Japanese system, using Tn5 based technology. pUAV45 clone contained a 25.4 kb Xoo genomic DNA insert. Southern blot analysis with avrXa10 as the probe showed that DNA insert in pUAV45 shares homology with avrX10. Furthermore within the Xoo insert, a smaller 5.7 kb KpnI fragment (pUAVSk) was identified through hybridization with avrXa10. The transformation of pUAV45 and pUAV5k into the strain Pxo99 (race 6 in Philippine system) led to the decrease of Pxo99pathogenicity on rice cultivar Wase Aikoku 3 (Xa3) and the increase of the pathogen pathogenicity on Cas209 (Xa10). The result of sequence analysis showed that there is a 2598 bp open reading frame (ORF) within the 5.7 kb Kpn 1 fragment (pUAVSk). The ORF shared high identity (97 % ) with avrXa10. The deduced sequence of the ORF contained 8.5 tandem repeat units of 34-amino-acids, one leucine zipper (LZ), three nuclear localization signal (NLS) motifs, and an acidic activation transcriptional domain (AAD) at C-terminus.We named this ORF avrXa3 and it is classified as a new member of avrBs3 (avr/pth) family with the dual-function determined by alternations of avirulence and aggressiveness on rice cultivars carrying different ‘ R' genes.

  13. RUBY-1: a randomized, double-blind, placebo-controlled trial of the safety and tolerability of the novel oral factor Xa inhibitor darexaban (YM150) following acute coronary syndrome

    DEFF Research Database (Denmark)

    Steg, Ph Gabriel; Mehta, Shamir R; Jukema, J Wouter;

    2011-01-01

    To establish the safety, tolerability and most promising regimen of darexaban (YM150), a novel, oral, direct factor Xa inhibitor, for prevention of ischaemic events in acute coronary syndrome (ACS).......To establish the safety, tolerability and most promising regimen of darexaban (YM150), a novel, oral, direct factor Xa inhibitor, for prevention of ischaemic events in acute coronary syndrome (ACS)....

  14. Transgenic expression of the rice Xa21 pattern recognition receptor in banana (Musa sp.) confers resistance to Xanthomonas campestris pv. musacearum

    Science.gov (United States)

    Tripathi, Jaindra Nath; Lorenzen, Jim; Bahar, Ofir; Ronald, Pamela; Tripathi, Leena

    2014-01-01

    Summary Banana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestris pv. musacearum (Xcm), is the most devastating disease of banana in east and central Africa. The spread of BXW threatens the livelihood of millions of African farmers who depend on banana for food security and income. There are no commercial chemicals, bio-control agents or resistant cultivars available to control BXW. Here we take advantage of the robust resistance conferred by the rice pattern recognition receptor (PRR), XA21, to the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo). We identified a set of genes required for activation of Xa21 mediated immunity (rax) that were conserved in both Xoo and Xcm. Based on the conservation, we hypothesized that intergeneric transfer of Xa21 would confer resistance to Xcm. We evaluated 25 transgenic lines of the banana cultivar ‘Gonja manjaya’ (AAB) using a rapid bioassay and 12 transgenic plants in the glass house for resistance against Xcm. About fifty percent of the transgenic lines showed complete resistance to Xcm in both assays. In contrast, all of the non-transgenic control plants showed severe symptoms that progressed to complete wilting. These results indicate that the constitutive expression of the rice Xa21 gene in banana results in enhanced resistance against Xcm. Furthermore this work demonstrates the feasibility of PRR gene transfer between monocotyledonous species and provides a valuable new tool for controlling the BXW pandemic of banana, a staple food for 100 million people in east Africa. PMID:24612254

  15. Transgenic expression of the rice Xa21 pattern-recognition receptor in banana (Musa sp.) confers resistance to Xanthomonas campestris pv. musacearum.

    Science.gov (United States)

    Tripathi, Jaindra N; Lorenzen, Jim; Bahar, Ofir; Ronald, Pamela; Tripathi, Leena

    2014-08-01

    Banana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestris pv. musacearum (Xcm), is the most devastating disease of banana in east and central Africa. The spread of BXW threatens the livelihood of millions of African farmers who depend on banana for food security and income. There are no commercial chemicals, biocontrol agents or resistant cultivars available to control BXW. Here, we take advantage of the robust resistance conferred by the rice pattern-recognition receptor (PRR), XA21, to the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo). We identified a set of genes required for activation of Xa21-mediated immunity (rax) that were conserved in both Xoo and Xcm. Based on the conservation, we hypothesized that intergeneric transfer of Xa21 would confer resistance to Xcm. We evaluated 25 transgenic lines of the banana cultivar 'Gonja manjaya' (AAB) using a rapid bioassay and 12 transgenic lines in the glasshouse for resistance against Xcm. About 50% of the transgenic lines showed complete resistance to Xcm in both assays. In contrast, all of the nontransgenic control plants showed severe symptoms that progressed to complete wilting. These results indicate that the constitutive expression of the rice Xa21 gene in banana results in enhanced resistance against Xcm. Furthermore, this work demonstrates the feasibility of PRR gene transfer between monocotyledonous species and provides a valuable new tool for controlling the BXW pandemic of banana, a staple food for 100 million people in east Africa. PMID:24612254

  16. Prevention of venous thromboembolism with an oral factor Xa inhibitor, YM150, after total hip arthroplasty. A dose finding study (ONYX-2)

    DEFF Research Database (Denmark)

    Eriksson, B I; Turpie, A G G; Lassen, M R;

    2010-01-01

    BACKGROUND: Anticoagulant prophylaxis substantially reduces the risk of venous thromboembolism (VTE) after major orthopedic surgery. The direct factor Xa inhibitor YM150 is currently under investigation for the prevention of VTE, stroke and ischemic vascular events in patients after orthopedic su...

  17. Alboserpin, a Factor Xa Inhibitor from the Mosquito Vector of Yellow Fever, Binds Heparin and Membrane Phospholipids and Exhibits Antithrombotic Activity

    Czech Academy of Sciences Publication Activity Database

    Calvo, E.; Mizurini, D.M.; Sa-Nunes, A.; Ribeiro, J.M.C.; Andersen, J. F.; Mans, B.J.; Monteiro, R.Q.; Kotsyfakis, Michalis; Francischetti, I.M.B.

    2011-01-01

    Roč. 286, č. 32 (2011), 27998-28010. ISSN 0021-9258 Institutional research plan: CEZ:AV0Z60220518 Keywords : serpin * mosquito * Aedes albopictus * phospholipids * Factor Xa * heparin * binding affinity * coagulation * thrombus * bleeding Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 4.773, year: 2011

  18. Search for anomalons in interactions of neon-22 nuclei with emulsion nuclei at 4. 1xA GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Bannik, B.P.; Batusov, Y.A.; Bokova, L.N.; Vokalova, A.; Kuznetsov, O.M.; Lyukov, V.V.; Piskaleva, O.V.; Tolstov, K.D.; Tret' yak, V.I.; Shabratova, G.S.; Andreeva, N.P.; Anzon, Z.V.; Bubnov, V.I.; Gaitinov, A.S.; Eremenko, L.E.; Kalyachkina, G.S.; Kanygina, =.K.; Chasnikov, I.Y.; Gitsok, M.; Marin, A.; Roshu, H.; Haiduk, M.; Hasegan, D.; Bobodzhanov, I.; Leskin, V.A.; Mukhtarov, A.; Shermatov, S.M.; Khoshmukhamedov, R.A.; Dzhuranova, M.S.; Salomov, D.A.; Avetyan, F.A.; Krishchyan, V.M.; Marutyan, N.A.; Matevosyan, K.; Sarkisova, L.G.; Lepekhin, F.G.; Simonov, B.B.; Koraba, J.; Korabovi, M.; Silesh, E.; Wilcincka, B.; Volter, V.; Vosek, B.; Olshecki, A.; Holyncki, R.; Antonchik, V.A.; Bakaev, V.A.; Belousov, A.V.; Bogdanov, S.D.; Ostroumov, V.I.; Bogdanov, V.G.; Plyushchev, V.A.; Solov' eva, Z.I.; Adamovich, M.I.; Larionova, V.G.; Orlova, G.I.; Salmanova, N.A.; Tret' yakova, M.T.; Kharlamov, S.P.; Azimov, S.A.; Abduzhamilov, A.; Abduzhamilov, S.; Gadzhieva, S.; Gulamov, K.G.; Dzhuraev, M.

    1984-02-25

    The mean free path before an inelastic interaction of relativistic fragments of neon-22 nuclei with emulsion nuclei at a momentum of 4.1xA GeV/c is studied as a function of the distance traversed by the fragments. No such dependence is found for fragments with charges from 3 to 9.

  19. Efficient selection of homozy-gous lines of hybrid rice restorer with the transgene Xa21 using test cross and PCR

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The homozygous restorer lines with a single copy of the transgene Xa21 have been obtained from the progenies of transgenic Minghui63 and Yanhui559 plants through PCR marker-assisted selection and test cross. These homozygous transgenic restorer lines can be used to breed hybrid rice with high resistance to bacterial leaf blight.

  20. Cooperative Regulation of the Activity of Factor Xa within Prothrombinase by Discrete Amino Acid Regions from Factor Va Heavy Chain†

    Science.gov (United States)

    2008-01-01

    The prothrombinase complex catalyzes the activation of prothrombin to α-thrombin. We have repetitively shown that amino acid region 695DYDY698 from the COOH terminus of the heavy chain of factor Va regulates the rate of cleavage of prothrombin at Arg271 by prothrombinase. We have also recently demonstrated that amino acid region 334DY335 is required for the optimal activity of prothrombinase. To assess the effect of these six amino acid residues on cofactor activity, we created recombinant factor Va molecules combining mutations at amino acid regions 334–335 and 695−698 as follows: factor V3K (334DY335 → KF and 695DYDY698 → KFKF), factor VKF/4A (334DY335 → KF and 695DYDY698 → AAAA), and factor V6A (334DY335 → AA and 695DYDY698 → AAAA). The recombinant factor V molecules were expressed and purified to homogeneity. Factor Va3K, factor VaK4/4A, and factor Va6A had reduced affinity for factor Xa, when compared to the affinity of the wild-type molecule (factor VaWt) for the enzyme. Prothrombinase assembled with saturating concentrations of factor Va3K had a 6-fold reduced second-order rate constant for prothrombin activation compared to the value obtained with prothrombinase assembled with factor VaWt, while prothrombinase assembled with saturating concentrations of factor VaKF/4A and factor Va6A had approximately 1.5-fold reduced second-order rate constants. Overall, the data demonstrate that amino acid region 334–335 together with amino acid region 695−698 from factor Va heavy chain are part of a cooperative mechanism within prothrombinase regulating cleavage and activation of prothrombin by factor Xa. PMID:18991406

  1. Exploration of 4,4-disubstituted pyrrolidine-1,2-dicarboxamides as potent, orally active Factor Xa inhibitors with extended duration of action.

    Science.gov (United States)

    Van Huis, Chad A; Casimiro-Garcia, Agustin; Bigge, Christopher F; Cody, Wayne L; Dudley, Danette A; Filipski, Kevin J; Heemstra, Ronald J; Kohrt, Jeffrey T; Leadley, Robert J; Narasimhan, Lakshmi S; McClanahan, Thomas; Mochalkin, Igor; Pamment, Michael; Peterson, J Thomas; Sahasrabudhe, Vaishali; Schaum, Robert P; Edmunds, Jeremy J

    2009-03-15

    Aiming to improve upon previously disclosed Factor Xa inhibitors, a series of 4,4-disubstituted pyrrolidine-1,2-dicarboxamides were explored with the intent of increasing the projected human half-life versus 5 (projected human t(1/2)=6 h). A stereospecific route to compounds containing a 4-aryl-4-hydroxypyrrolidine scaffold was developed, resulting in several compounds that demonstrated an increase in the half-life as well as an increase in the in vitro potency compared to 5. Reported herein is the discovery of 26, containing a (2R,4S)-4-hydroxy-4-(2,4-difluorophenyl)-pyrrolidine scaffold, which is a selective, orally bioavailable, efficacious Factor Xa inhibitor that appears suitable for a once-daily dosing (projected human t(1/2)=23 h). PMID:19231206

  2. Human plasma kallikrein and tissue kallikrein binding to a substrate based on the reactive site of a factor Xa inhibitor isolated from Bauhinia ungulata seeds.

    Science.gov (United States)

    Oliva, M L; Andrade, S A; Batista, I F; Sampaio, M U; Juliano, M; Fritz, H; Auerswald, E A; Sampaio, C A

    1999-12-01

    Kunitz type Bauhinia ungulata factor Xa inhibitor (BuXI) was purified from B. ungulata seeds. BuXI inactivates factor Xa and human plasma kallikrein (HuPK) with Ki values of 18.4 and 6.9 nM, respectively. However, Bauhinia variegata trypsin inhibitor (BvTI) which is 70% homologous to BuXI does not inhibit factor Xa and is less efficient on HuPK (Ki = 80 nM). The comparison between BuXI and BvTI reactive site structure indicates differences at Met59, Thr66 and Met67 residues. The hydrolysis rate of quenched fluorescence peptide substrates based on BuXI reactive site sequence, Abz-VMIAALPRTMFIQ-EDDnp (leading peptide), by HuPK and porcine pancreatic kallikrein (PoPK) is low, but hydrolysis is enhanced with Abz-VMIAALPRTMQ-EDDnp, derived from the leading peptide shortened by removing the dipeptide Phe-Ileu from the C-terminal portion, for HuPK (Km = 0.68 microM, k(cat)/Km = 1.3 x 10(6) M(-1) s(-1)), and the shorter substrate Abz-LPRTMQ-EDDnp is better for PoPK (Km = 0.66 microM, k(cat)/Km = 2.2 x 10(3) M(-1) s(-1)). The contribution of substrate methionine residues to HuPK and PoPK hydrolysis differs from that observed with factor Xa. The determined Km and k(cat) values suggest that the substrates interact with kallikreins the same as an enzyme and inhibitor interacts to form complexes. PMID:10615004

  3. MODEL GROUP INVESTIGATION (GI) DIPADU PROBLEM BASED LEARNING (PBL) UNTUK MENINGKATKAN KETERAMPILAN BEKERJA ILMIAH DAN KEMAMPUAN KOGNITIF SISWA KELAS X-A1 SMAN 2 MALANG

    OpenAIRE

    Prasmala, Erfitra Rezqi

    2016-01-01

    ABSTRACTThe purpose of this study to improve (1) the skills of scientific work, (2) the cognitive abilities of students of class X-A1 at SMAN 2 Malang through the application of models Group Investigation (GI) combined with the Problem Based Learning (PBL). Type of research is Action Research Action (PTK) with research subjects-A1 class X SMAN 2 Malang. Data collected by the research instrument consisting of a sheet of observation skills of scientific work, scientific work reports, students' ...

  4. Drug-Drug Interaction Studies of Cardiovascular Drugs Involving P-Glycoprotein, an Efflux Transporter, on the Pharmacokinetics of Edoxaban, an Oral Factor Xa Inhibitor

    OpenAIRE

    Mendell, Jeanne; Zahir, Hamim; Matsushima, Nobuko; Noveck, Robert; Lee, Frank; Chen, Shuquan; Zhang, George; Shi, Minggao

    2013-01-01

    Background Edoxaban, an oral direct factor Xa inhibitor, is in development for thromboprophylaxis, including prevention of stroke and systemic embolism in patients with atrial fibrillation (AF). P-glycoprotein (P-gp), an efflux transporter, modulates absorption and excretion of xenobiotics. Edoxaban is a P-gp substrate, and several cardiovascular (CV) drugs have the potential to inhibit P-gp and increase drug exposure. Objective To assess the potential pharmacokinetic interactions of edoxaban...

  5. Microfluidic Chip-Based Online Screening Coupled to Mass Spectrometry: Identification of Inhibitors of Thrombin and Factor Xa.

    Science.gov (United States)

    Iyer, Janaki Krishnamoorthy; Otvos, Reka A; Kool, Jeroen; Kini, R Manjunatha

    2016-02-01

    Thrombin and factor Xa (FXa) are critical enzymes of the blood coagulation cascade and are excellent targets of anticoagulant agents. Natural sources present an array of anticoagulants that can be developed as antithrombotic drugs. High-resolution, online screening techniques have been developed for the identification of drug leads from complex mixtures. In this study, we have developed and optimized a microfluidic online screening technique coupled to nano-liquid chromatography (LC) and in parallel with a mass spectrometer for the identification of thrombin and FXa inhibitors in mixtures. Inhibitors eluting from the nano-LC were split postcolumn in a 1:1 ratio; half was fed into a mass spectrometer (where its mass is detected), and the other half was fed into a microfluidic chip (which acts as a microreactor for the online assays). With our platform, thrombin and FXa inhibitors were detected in the assay in parallel with their mass identification. These methods are suitable for the identification of inhibitors from sample amounts as low as sub-microliter volumes. PMID:26323281

  6. AutoGPA-Based 3D-QSAR Modeling and Molecular Docking Study on Factor Xa Inhibitors as Anticoagulant Agents

    Directory of Open Access Journals (Sweden)

    Guo Fang Yuan

    2016-01-01

    Full Text Available The three-dimensional-quantitative structure activity relationship (3D-QSAR studies were performed on a series of direct factor Xa (FXa inhibitors using AutoGPA-based modeling method in this paper. A training set of 38 molecules and a test set containing 10 molecules were used to build the 3D-QSAR model and validate the derived model, respectively. The developed model with correlation coefficients (r2 of 0.8564 and cross-validated correlation coefficients (q2 of 0.6721 were validated by an external test set of 10 molecules with predicted correlation coefficient (rpred2 of 0.6077. Docking study of FXa inhibitors and FXa active site was performed to check the induced pharmacophore query and comparative molecular field analysis (CoMFA contour maps using MOE2012.10. It was proved to be coincidence with the interaction information between ligand and FXa active site and was rendered to provide a useful tool to improve FXa inhibitors.

  7. Edoxaban: A Novel Factor Xa Inhibitor for the Management of Non-valvular Atrial Fibrillation and Venous Thromboembolism.

    Science.gov (United States)

    Kubli, Kara A; Snead, Jessica A; Cheng-Lai, Angela

    2016-01-01

    Warfarin has been a highly prevalent agent for over 70 years; however, its use has been limited by drug-drug interactions, adverse events, and the need for frequent monitoring. To minimize these complications, several non-vitamin K oral anticoagulants have been approved, including the latest agent, edoxaban. Edoxaban is a factor Xa inhibitor approved for the prevention of stroke/systemic embolism in patients with non-valvular atrial fibrillation and for the treatment of venous thromboembolism. Edoxaban was largely studied in the Edoxaban versus Warfarin in Patients with Atrial Fibrillation (ENGAGE AF-TIMI 48) and Edoxaban versus Warfarin for the Treatment of Symptomatic Venous Thromboembolism (Hokusai-VTE) trials, both showing noninferiority when compared with warfarin. Similar to other oral anticoagulants, the most serious adverse effects of edoxaban are related to bleeding. However, there are currently no approved reversal agents. Andexanet alfa and ciraparantag are the latest agents being studied for reversal. This article provides an overview of the safety and efficacy along with the advantages and disadvantages of edoxaban. PMID:26991962

  8. Comparison of 3,000 and 5,000 IU aXa/day certoparin in the prevention of deep-vein thrombosis after total hip replacement

    Directory of Open Access Journals (Sweden)

    Bramlage Peter

    2012-06-01

    Full Text Available Abstract Background The aim was to investigate, whether 5,000 IUaXa/day certoparin lowers the incidence of deep vein thrombosis (DVT in patients undergoing elective hip replacement surgery vs. 3,000 IUaXa/day. Double-blind, multicenter, randomised trial in 500 patients. Primary endpoint: incidence of symptomatic or asymptomatic DVT (bilateral ascending venography. Results Mean age was 71 ± 10 years with a higher prevalence of previous DVT (8vs.4% and pulmonary embolism (PE (4vs.1% in the high dose group. Mean duration of surgery was 82 ± 32 and 85 ± 36 min. DVT was detected in 28 (11.1% of the low dose and 35 (14.1% of the high dose group (p = n.s.. Combined distal-proximal DVT was observed in 5 (2% and 4 (1.6% patients respectively. No difference in bleeding events was found. Conclusion This trial confirms prior data showing that the conventional dosage of 3,000 IU aXa is effective and safe for the prevention of venous thromboembolic events after hip replacement surgery.

  9. Daboxin P, a Major Phospholipase A2 Enzyme from the Indian Daboia russelii russelii Venom Targets Factor X and Factor Xa for Its Anticoagulant Activity

    Science.gov (United States)

    Iyer, Janaki Krishnamurthy; Shih, Norrapat; Majumder, Munmi; Mattaparthi, Venkata Satish Kumar; Mukhopadhyay, Rupak; Doley, Robin

    2016-01-01

    In the present study a major protein has been purified from the venom of Indian Daboia russelii russelii using gel filtration, ion exchange and Rp-HPLC techniques. The purified protein, named daboxin P accounts for ~24% of the total protein of the crude venom and has a molecular mass of 13.597 kDa. It exhibits strong anticoagulant and phospholipase A2 activity but is devoid of any cytotoxic effect on the tested normal or cancerous cell lines. Its primary structure was deduced by N-terminal sequencing and chemical cleavage using Edman degradation and tandem mass spectrometry. It is composed of 121 amino acids with 14 cysteine residues and catalytically active His48 -Asp49 pair. The secondary structure of daboxin P constitutes 42.73% of α-helix and 12.36% of β-sheet. It is found to be stable at acidic (pH 3.0) and neutral pH (pH 7.0) and has a Tm value of 71.59 ± 0.46°C. Daboxin P exhibits anticoagulant effect under in-vitro and in-vivo conditions. It does not inhibit the catalytic activity of the serine proteases but inhibits the activation of factor X to factor Xa by the tenase complexes both in the presence and absence of phospholipids. It also inhibits the tenase complexes when active site residue (His48) was alkylated suggesting its non-enzymatic mode of anticoagulant activity. Moreover, it also inhibits prothrombinase complex when pre-incubated with factor Xa prior to factor Va addition. Fluorescence emission spectroscopy and affinity chromatography suggest the probable interaction of daboxin P with factor X and factor Xa. Molecular docking analysis reveals the interaction of the Ca+2 binding loop; helix C; anticoagulant region and C-terminal region of daboxin P with the heavy chain of factor Xa. This is the first report of a phospholipase A2 enzyme from Indian viper venom which targets both factor X and factor Xa for its anticoagulant activity. PMID:27089306

  10. Daboxin P, a Major Phospholipase A2 Enzyme from the Indian Daboia russelii russelii Venom Targets Factor X and Factor Xa for Its Anticoagulant Activity.

    Directory of Open Access Journals (Sweden)

    Maitreyee Sharma

    Full Text Available In the present study a major protein has been purified from the venom of Indian Daboia russelii russelii using gel filtration, ion exchange and Rp-HPLC techniques. The purified protein, named daboxin P accounts for ~24% of the total protein of the crude venom and has a molecular mass of 13.597 kDa. It exhibits strong anticoagulant and phospholipase A2 activity but is devoid of any cytotoxic effect on the tested normal or cancerous cell lines. Its primary structure was deduced by N-terminal sequencing and chemical cleavage using Edman degradation and tandem mass spectrometry. It is composed of 121 amino acids with 14 cysteine residues and catalytically active His48 -Asp49 pair. The secondary structure of daboxin P constitutes 42.73% of α-helix and 12.36% of β-sheet. It is found to be stable at acidic (pH 3.0 and neutral pH (pH 7.0 and has a Tm value of 71.59 ± 0.46°C. Daboxin P exhibits anticoagulant effect under in-vitro and in-vivo conditions. It does not inhibit the catalytic activity of the serine proteases but inhibits the activation of factor X to factor Xa by the tenase complexes both in the presence and absence of phospholipids. It also inhibits the tenase complexes when active site residue (His48 was alkylated suggesting its non-enzymatic mode of anticoagulant activity. Moreover, it also inhibits prothrombinase complex when pre-incubated with factor Xa prior to factor Va addition. Fluorescence emission spectroscopy and affinity chromatography suggest the probable interaction of daboxin P with factor X and factor Xa. Molecular docking analysis reveals the interaction of the Ca+2 binding loop; helix C; anticoagulant region and C-terminal region of daboxin P with the heavy chain of factor Xa. This is the first report of a phospholipase A2 enzyme from Indian viper venom which targets both factor X and factor Xa for its anticoagulant activity.

  11. [Surgery and invasive procedures in patients on long-term treatment with oral direct thrombin or factor Xa inhibitors].

    Science.gov (United States)

    Sié, P; Samama, C-M; Godier, A; Rosencher, N; Steib, A; Llau, J-V; van der Linden, P; Pernod, G; Lecompte, T; Gouin-Thibault, I; Albaladejo, P

    2011-09-01

    Direct oral anticoagulants (DOAs), inhibitors of factor IIa or Xa, are expected to replace vitamin K antagonists in most of their indications. It is likely that patients on long-term treatment with DOAs will be exposed to elective or emergency surgery or invasive procedures. Due to the present lack of experience in such conditions, we cannot make recommendations, but only propose perioperative management for optimal safety as regards the risk of bleeding and thrombosis. DOAs may increase surgical bleeding, they have no validated antagonists, they cannot be monitored by simple, standardised laboratory assays, and their pharmacokinetics vary significantly from patient to patient. Although DOAs differ in many respects, the proposals in the perioperative setting need not be specific to each. For procedures with low risk of haemorrhage, a therapeutic window of 48 h (last administration 24h before surgery, restart 24h after) is proposed. For procedures with medium or high haemorrhagic risk, we suggest stopping DOAs 5 days before surgery to ensure complete elimination of the drug in all patients. The treatment should be resumed only when the risk of bleeding has been controlled. In patients with a high risk of thrombosis (e.g. those in atrial fibrillation with an antecedent of stroke), bridging with heparin (low molecular weight, or unfractionated if the former is contraindicated) is proposed. In emergency, the procedure should be postponed for as long as possible (minimum 1-2 half-lives) and non-specific anti-haemorrhagic agents, such as recombinant human activated factor VIIa, or prothrombin concentrates, should not be given for prophylactic reversal, due to their uncertain benefit-risk. PMID:21820844

  12. CP1H-XA40CDR-A可编程器内置模拟量功能在制冷试验装置中应用%The Built-in Analog Functions of CP1H-XA40CDR-A Programmable Used in the Refrigeration Test Device

    Institute of Scientific and Technical Information of China (English)

    杨厚太; 郝颖磊

    2011-01-01

    主要介绍CP1H-XA40CDR-A可编程控制器的内置模拟量输入功能在制冷试验装置中的应用,着重介绍模拟量输入在恒温水箱上的应用,模拟输出在控制无级冷水机组上的应用以及编程时候需要注意的事项。%This article mainly introduces the CP1H-XA40CDR-A built-in analog input capability of programmable logic controller application in refrigeration test equipment,focuses on analog input application in thermostat water tank,analog output in controlled stepless chiller applications,and programming time on matters requiring attention.

  13. Measuring the Luminosity of a gamma gamma Collider with gamma gamma -> l+ l- gamma Events

    OpenAIRE

    Makarenko, V.; Moenig, K.; Shishkina, T.

    2003-01-01

    The process gamma gamma -> l+ l- is highly suppressed when the total angular momentum of the two colliding photons is zero so that it cannot be used for luminosity determination. This configuration, however is needed for Higgs production at a photon collider. It will be shown that the process gamma gamma -> l+ l- gamma can be used in this case to measure the luminosity of a collider with a precision that is good enough not to limit the error on the partial decay width Gamma(H -> gamma gamma).

  14. X and gamma rays irradiation tests for evaluating performances of Italian dosimetry services

    International Nuclear Information System (INIS)

    The ENEA (Italian Agency for New Technologies, Energy and the Environment)-EDP Group (Personal Dosimetry Experts) has already evaluated the reliability of more than 50% of the 70 Italian personal dosimetry services, which agreed to test their dosimeters through X and gamma irradiation in air. Film,TL and both film and TL are used as detectors. The X and gamma rays energy ranges from 30 keV to 1.250 keV (beam defined by ISO 4037). Exposures range from 5.2 10-6 C/kg to 1.3 10-3 C/kg. Some dosimeters have been irradiated with a single energy level and others with two energy levels. For each one of the nearly 4.000 dosimeters already tested, the ratio R has been calculated: R = Xv/Xa where: Xv is the exposure evaluated by the service, Xa is the actual exposure. The R distributions have been analysed for the dosimeters using film or TL as detectors, as a function of irradiation energy and as a function of exposure values. The results obtained by all tested services are commented. Separate comments deal also with possible reasons of the failures to pass the tests

  15. Efficacy and safety of rivaroxaban compared with warfarin among elderly patients with nonvalvular atrial fibrillation in the Rivaroxaban Once Daily, Oral, Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF)

    DEFF Research Database (Denmark)

    Halperin, Jonathan L; Hankey, Graeme J; Wojdyla, Daniel M;

    2014-01-01

    BACKGROUND: Nonvalvular atrial fibrillation is common in elderly patients, who face an elevated risk of stroke but difficulty sustaining warfarin treatment. The oral factor Xa inhibitor rivaroxaban was noninferior to warfarin in the Rivaroxaban Once Daily, Oral, Direct Factor Xa Inhibition Compar...

  16. Identification of microsatellite markers (SSR linked to a new bacterial blight resistance gene xa33(t in rice cultivar ‘Ba7’

    Directory of Open Access Journals (Sweden)

    Theerayut Toojinda

    2009-05-01

    Full Text Available This study attempts to identify a new source of bacterial blight (BB resistance gene and microsatellite makers (SSR linked to it. A total number of 139 F2 progenies generated from a cross between the resistant donor ‘Ba7’and ‘Pin Kaset’ were developed and used for this study. A Thai Xoo isolate, TXO16, collected from Phitsanulok province, was used to evaluate the resistance reaction in the F2 population. The segregation ratio of resistance (R and susceptibility (S was statistically fitted to 1R:3S model indicating single recessive gene segregation. Twenty F2 individuals consisting of 10 resistant and 10 susceptible plants were chosen for DNA analysis. Sixty-two polymorphic markers covering all rice chromosomes were used to identify the location and linked markers of the resistance gene. Four SSR markers, viz. RM30, RM7243, RM5509 and RM400, located on the long arm of rice chromosome 6, could clearly discriminate between resistant and susceptible phenotypes, and 161 BC2F2:3 individuals carrying BB resistance gene were developed through MAS using these SSR markers. This population was inoculated with TXO16 to validate and confirm the location of the gene and linked markers. The segregation ratio was statistically fitted to 1R:3S model confirming a recessive nature of the gene action in this germplasm. Phenotypic-genotypic association including five additional markers suggested that RM20590 was tightly linked to this resistance gene (R2=59.12 %. The BB phenotype was controlled by a recessive gene with incomplete dominance of susceptible allele providing intermediate resistance to Xoo pathogen in heterozygotes. The location of the gene was in the vicinity of a dominant gene, Xa7, which was previously reported. However, the resistance gene identified here was different from Xa7 because of the different nature of gene action. Consequently, this gene was tentatively designated as xa33(t. The resistance gene from rice cultivar ‘Ba7’ and the

  17. Gamma camera

    International Nuclear Information System (INIS)

    The design of a collimation system for a gamma camera for use in nuclear medicine is described. When used with a 2-dimensional position sensitive radiation detector, the novel system can produce superior images than conventional cameras. The optimal thickness and positions of the collimators are derived mathematically. (U.K.)

  18. Gamma-ray methods

    International Nuclear Information System (INIS)

    Bulk analysis techniques using gamma radiation are described. The methods include gamma-ray induced reactions, selective gamma-ray scattering and methods which rely on natural radioactivity. The gamma-ray resonance scattering technique can be used for the determination of copper and nickel in bulk samples and drill cores. The application of gamma-gamma methods to iron ore analysis is outlined

  19. Prevention of venous thromboembolism with an oral factor Xa inhibitor, YM150, after total hip arthroplasty. A dose finding study (ONYX-2)

    DEFF Research Database (Denmark)

    Eriksson, B I; Turpie, A G G; Lassen, M R; Prins, M H; Agnelli, G; Kälebo, P; Wetherill, G; Wilpshaar, J W; Meems, L

    2010-01-01

    BACKGROUND: Anticoagulant prophylaxis substantially reduces the risk of venous thromboembolism (VTE) after major orthopedic surgery. The direct factor Xa inhibitor YM150 is currently under investigation for the prevention of VTE, stroke and ischemic vascular events in patients after orthopedic...... surgery, with atrial fibrillation and with acute coronary syndrome, respectively. OBJECTIVES: To investigate the efficacy and safety of YM150 for the prevention of VTE following elective total hip arthroplasty. PATIENTS/METHODS: Patients were randomized to postoperative, once-daily, oral YM150 (5, 10, 30......, 60 or 120 mg) (double-blind) or preoperative subcutaneous (open label) enoxaparin (40 mg) for 5 weeks. The primary efficacy endpoint comprised VTE diagnosed by mandatory bilateral venography or verified symptomatic deep vein thrombosis (DVT) plus all deaths up to 9 days after surgery. The primary...

  20. Contribution of Amino Acid Region 659−663 of Factor Va Heavy Chain to the Activity of Factor Xa within Prothrombinase†,‡

    Science.gov (United States)

    2010-01-01

    Factor Va, the cofactor of prothrombinase, is composed of heavy and light chains associated noncovalently in the presence of divalent metal ions. The COOH-terminal region of the heavy chain contains acidic amino acid clusters that are important for cofactor activity. In this work, we have investigated the role of amino acid region 659−663, which contains five consecutive acidic amino acid residues, by site-directed mutagenesis. We have generated factor V molecules in which all residues were mutated to either lysine (factor V5K) or alanine (factor V5A). We have also constructed a mutant molecule with this region deleted (factor VΔ659−663). The recombinant molecules along with wild-type factor V (factor VWT) were transiently expressed in mammalian cells, purified, and assessed for cofactor activity. Two-stage clotting assays revealed that the mutant molecules had reduced clotting activities compared to that of factor VaWT. Kinetic analyses of prothrombinase assembled with the mutant molecules demonstrated diminished kcat values, while the affinity of all mutant molecules for factor Xa was similar to that for factor VaWT. Gel electrophoresis analyses of plasma-derived and recombinant mutant prothrombin activation demonstrated delayed cleavage of prothrombin at both Arg320 and Arg271 by prothrombinase assembled with the mutant molecules, resulting in meizothrombin lingering throughout the activation process. These results were confirmed after analysis of the cleavage of FPR-meizothrombin. Our findings provide new insights into the structural contribution of the acidic COOH-terminal region of factor Va heavy chain to factor Xa activity within prothrombinase and demonstrate that amino acid region 659−663 from the heavy chain of the cofactor contributes to the regulation of the rate of cleavage of prothrombin by prothrombinase. PMID:20722419

  1. Gamma sterilization

    International Nuclear Information System (INIS)

    The lethal action of gamma radiation is based on the disruption of DNA molecules. The sensitivity of (micro)organisms towards radiation varies. In industrial sterilization generally a radiation dose of 25 kGy is applied. Industrial radiation facilities consist of a radiation source, a biological shield and an automatic transport system. Radiation penetrates from all directions into the product and at all positions approximately the same dose is received. The only variable parameter is the velocity of the transport, which in turn determines the total dose received by the product. A number of provisions ensure that the product receives the correct treatment. Some materials show dose-dependent changes resulting from a radiation treatment. Several manufacturers of plastics offer radiation-stable compositions. Hospitals and other users of an irradiation facility have to ensure that the product they offer for gamma sterilization, can stand a treatment. 6 refs.; 2 figs.; 2 tabs

  2. GARCH Gamma

    OpenAIRE

    Robert F. Engle; Joshua V. Rosenberg

    1995-01-01

    This paper addresses the issue of hedging option positions when the underlying asset exhibits stochastic volatility. By parameterizing the volatility process as GARCH, and utilizing risk- neutral valuation, we estimate hedging parameters (delta and gamma) using Monte-Carlo simulation. We estimate hedging parameters for options on the Standard and Poor's 500 index, a bond futures index, a weighted foreign exchange rate index, and an oil futures index. We find that Black-Scholes and GARCH delta...

  3. Gamma teletopography

    International Nuclear Information System (INIS)

    The mapping of gamma sources radiation emission in a nuclear plant is an important safety point. A remote gamma ray mapping process was developed in SPS/CEA/SACLAY. It uses the ''pinhole camera'' principle, precursor of photography. It mainly consists of a radiation proof box, with a small orifice, containing sensitive emulsions at the opposite. A first conventional photographic type emulsion photographs the area. A second photographic emulsion shows up the gamma radiations. The superim position of the two shots gives immediate informations of the precise location of each source of radiation in the observed area. To make easier the presentation and to improve the accuracy of the results for radiation levels mapping, the obtained films are digitally processed. The processing assigns a colours scale to the various levels of observed radiations. Taking account physical data and standard parameters, it gets possible to estimate the dose rate. The device is portable. Its compactness and fully independent nature make it suitable for use anywhere. It can be adapted to a remote automatic handling system, robot... so as to avoid all operator exposure when the local dose rate is too high

  4. Limits on the quartic couplings $Z\\gamma\\gamma\\gamma$ and $ZZ\\gamma\\gamma$ from $e^+e^-$ colliders

    CERN Document Server

    Gutierrez-Rodriguez, A; Montano, J; Pérez, M A

    2013-01-01

    We obtain limits on the quartic neutral gauge bosons couplings $Z\\gamma\\gamma\\gamma$ and $ZZ\\gamma\\gamma$ using LEP 2 data published by the L3 Collaboration on the reactions $e^+e^-\\to \\gamma\\gamma\\gamma, Z\\gamma\\gamma$. We also obtain $95 {0.8mm}%$ C. L. limits on these couplings at the future linear colliders energies. The LEP 2 data induce limits of order $10^{-5}$ for the $Z\\gamma\\gamma\\gamma$ couplings and of order $10^{-2}$ for the $ZZ\\gamma\\gamma$ couplings, which are still above the respective Standard Model predictions. Future $e^+e^-$ linear colliders may improve these limits by one or two orders of magnitude.

  5. Gamma bursts

    International Nuclear Information System (INIS)

    The Vela satellite series has recently detected gamma bursts in the 0.2-1.5MeV energy range. These bursts last an average of from 0.1 to 10s and have a fine time structure, with pulses lasting less than several tens of milliseconds. With simultaneous observations from different satellites it has been possible to determine the spatial origin of some of the bursts. No correlation, however, has been made with known objects. In spite of the fragmentary character of the information received to date, several theories have already been proposed to account for these phenomena

  6. Fuzzy Gamma-hypersemigroups

    OpenAIRE

    R. Ameri; Sadeghi, R.

    2013-01-01

    We introduced and study fuzzy gamma-hypersemigroups, according to fuzzy semihyper- groups as previously defined [33] and prove that results in this respect. In this regard first we introduce fuzzy hyperoperation and then study fuzzy gamma-hypersemigroup. We will proceed by study fuzzy gamma-hyperideals and fuzzy gamma-bihyperideals. Also we study the relation between the classes of fuzzy gamma-hypersemigroups and semigroups. Precisely, we associate a gamma-hypersemigroup to every fuzzy hypers...

  7. On semi-exclusive measurement of $\\gamma\\gamma\\to\\gamma\\gamma$ scattering

    CERN Document Server

    Staszewski, Rafał

    2016-01-01

    The two-photon production of photon pairs, i.e. the $\\gamma\\gamma\\to\\gamma\\gamma$ process, is studied. Different production modes regarding the elastic or inelastic coupling of the intermediate-state photons to the protons are considered. The semi-exclusive measurement, where one intact proton is registered by a dedicated forward proton detector, is discussed. As an example, the signal and background simulations are performed for the $\\gamma\\gamma\\to\\gamma\\gamma$ process mediated by the hypothetical 750 GeV resonance.

  8. The discovery of (2R,4R)-N-(4-chlorophenyl)-N- (2-fluoro-4-(2-oxopyridin-1(2H)-yl)phenyl)-4-methoxypyrrolidine-1,2-dicarboxamide (PD 0348292), an orally efficacious factor Xa inhibitor.

    Science.gov (United States)

    Kohrt, Jeffrey T; Bigge, Christopher F; Bryant, John W; Casimiro-Garcia, Agustin; Chi, Liguo; Cody, Wayne L; Dahring, Tawny; Dudley, Danette A; Filipski, Kevin J; Haarer, Staci; Heemstra, Ron; Janiczek, Nancy; Narasimhan, Lakshmi; McClanahan, Thomas; Peterson, J Thomas; Sahasrabudhe, Vaisheli; Schaum, Robert; Van Huis, Chad A; Welch, Kathleen M; Zhang, Erli; Leadley, Robert J; Edmunds, Jeremy J

    2007-08-01

    Herein, we report the discovery of novel, proline-based factor Xa inhibitors containing a neutral P1 chlorophenyl pharmacophore. Through the additional incorporation of 1-(4-amino-3-fluoro-phenyl)-1H-pyridin-2-one 22, as a P4 pharmacophore, we discovered compound 7 (PD 0348292). This compound is a selective, orally bioavailable, efficacious FXa inhibitor that is currently in phase II clinical trials for the treatment and prevention of thrombotic disorders. PMID:17683371

  9. The pharmacokinetics of darexaban (YM150), an oral direct factor Xa inhibitor, are not affected by ketoconazole, a strong inhibitor of CYP3A and P-glycoprotein.

    Science.gov (United States)

    Groenendaal, Dorien; Strabach, Gregory; Garcia-Hernandez, Alberto; Kadokura, Takeshi; Heeringa, Marten; Mol, Roelof; Eltink, Charlotte; Onkels, Hartmut

    2014-05-01

    We investigated the effects of ketoconazole on the pharmacokinetics (PK) of the direct clotting factor Xa inhibitor darexaban (YM150) and its main active metabolite darexaban glucuronide (YM-222714) which almost entirely determines the antithrombotic effect. In this open-label, randomized, two-period crossover study, 26 healthy male volunteers received in one treatment period a single dose of darexaban 60 mg, and in the other treatment period, ketoconazole 400 mg once daily on Days 1-9 with a single dose of darexaban 60 mg on Day 4. Washout between periods was at least 1 week. The geometric mean ratio (90% confidence interval) of darexaban glucuronide (darexaban plus ketoconazole versus darexaban) for AUCinf was 1.11 (1.00, 1.23), and for Cmax 1.18 (1.03, 1.35). Darexaban concentrations remained very low (AUClast ∼196-fold lower) in relation to darexaban glucuronide concentrations. In conclusion, the PK of darexaban glucuronide was not affected to a clinically relevant degree by co-administration of the strong CYP3A/P-glycoprotein inhibitor, ketoconazole. The PK of the parent compound darexaban were changed, however, concentrations remained quantitatively insignificant in relation to the main active moiety, darexaban glucuronide. PMID:27128609

  10. Computational investigation of potential dosing schedules for a switch of medication from warfarin to rivaroxaban – an oral, direct Factor Xa inhibitor

    Directory of Open Access Journals (Sweden)

    Rolf eBurghaus

    2014-11-01

    Full Text Available The long-lasting anticoagulant effect of vitamin K antagonists can be problematic in cases of adverse drug reactions or when patients are switched to another anticoagulant therapy. The objective of this study was to examine in silico the anticoagulant effect of rivaroxaban, an oral, direct Factor Xa inhibitor, combined with the residual effect of discontinued warfarin. Our simulations were based on the recommended anticoagulant dosing regimen for stroke prevention in patients with atrial fibrillation. The effects of the combination of discontinued warfarin plus rivaroxaban were simulated using an extended version of a previously validated blood coagulation computer model. A strong synergistic effect of the two distinct mechanisms of action was observed in the first 2–3 days after warfarin discontinuation; thereafter, the effect was close to additive. Nomograms for the introduction of rivaroxaban therapy after warfarin discontinuation were derived for Caucasian and Japanese patients using safety and efficacy criteria described previously, together with the coagulation model. The findings of our study provide a mechanistic pharmacologic rationale for dosing schedules during the therapy switch from warfarin to rivaroxaban and support the switching strategies as outlined in the Summary of Product Characteristics and Prescribing Information for rivaroxaban.

  11. Pharmacokinetics and Pharmacodynamics of Edoxaban, a Non-Vitamin K Antagonist Oral Anticoagulant that Inhibits Clotting Factor Xa.

    Science.gov (United States)

    Parasrampuria, Dolly A; Truitt, Kenneth E

    2016-06-01

    Edoxaban, a once daily non-vitamin K antagonist oral anticoagulant, is a direct, selective, reversible inhibitor of factor Xa (FXa). In healthy subjects, single oral doses of edoxaban result in peak plasma concentrations within 1.0-2.0 h of administration, followed by a biphasic decline. Exposure is approximately dose proportional for once daily doses of 15-150 mg. Edoxaban is predominantly absorbed from the upper gastrointestinal tract, and oral bioavailability is approximately 62 %. Food does not affect total exposure to edoxaban. The terminal elimination half-life in healthy subjects ranges from 10 to 14 h, with minimal accumulation upon repeat once daily dosing up to doses of 120 mg. The steady-state volume of distribution is approximately 107 L, and total clearance is approximately 22 L/h; renal clearance accounts for approximately 50 % of total clearance, while metabolism and biliary secretion account for the remaining 50 %. Intrinsic factors, such as age, sex and race, do not affect edoxaban pharmacokinetics after renal function is taken into account. Oral administration of edoxaban results in rapid changes in anticoagulatory biomarkers, with peak effects on anticoagulation markers (such as anti-FXa), the prothrombin time and the activated partial thromboplastin time occurring within 1-2 h of dosing. PMID:26620048

  12. Peculiaridades da terapia trombolítica na síndrome nefrótica pediátrica: monitorização do fator anti-Xa Particularities of thrombolytic therapy in pediatric nephrotic syndrome: anti-factor Xa monitoring

    Directory of Open Access Journals (Sweden)

    Patrícia Zambi Meirelles

    2008-06-01

    Full Text Available OBJETIVO: Descrever a importância do tromboembolismo pulmonar (TEP na síndrome nefrótica pediátrica e o uso da heparina de baixo peso molecular como opção terapêutica segura e eficaz. DESCRIÇÃO DO CASO: Menino de 5,7 anos com síndrome nefrótica córtico-resistente e glomérulo-esclerose segmentar e focal foi internado devido à diarréia, distúrbios eletrolíticos e anasarca. No 11º dia de internação, evoluiu com desconforto respiratório súbito, cuja investigação mostrou área de alta probabilidade de TEP na cintilografia pulmonar ventilação/perfusão e obstrução em veia jugular interna esquerda ao ultra-som doppler. Iniciado suporte ventilatório com nebulização de oxigênio e anticoagulação com enoxaparina (2mg/kg/dia. Após seis dias, evoluiu com sintomas neurológicos compatíveis com episódio isquêmico transitório, sem alteração na tomografia computadorizada de crânio. A monitorização do fator anti-Xa no soro demonstrou nível subterapêutico e a dose de enoxaparina foi ajustada para 3mg/kg/dia. O edema e os sintomas pulmonares melhoraram e o paciente recebeu alta hospitalar após 33 dias. COMENTÁRIOS: Embora o TEP seja raro em crianças, a síndrome nefrótica é uma condição pró-trombótica que favorece a complicação. A heparina de baixo peso molecular pode ser considerada no tratamento e na profilaxia secundária do TEP, sendo importante monitorizar o nível sérico do fator anti-Xa para ajustar sua dose e promover tratamento seguro e eficaz.OBJECTIVE: Report the importance of pulmonary thromboembolism (PTE in pediatric nephrotic syndrome and the use of low molecular weight heparin (LMWH as an effective and secure therapeutic option. CASE DESCRIPTION: A 5.7 year-old boy with steroid-resistant nephrotic syndrome and focal segmental glomerulosclerosis was admitted to the pediatric unit with diarrhea, electrolyte disturbances and anasarca. On the 11th day of hospital stay, he developed a sudden

  13. Modulation gamma resonance spectroscopy

    International Nuclear Information System (INIS)

    Possibility to control dynamic processes in a matter through gamma-resonance modulation by high-frequency external variable fields in excess of inverse lifetimes of the Moessbauer nuclei excited states, that is, within the megahertz frequency range lies in the heart of the modulation gamma-resonance spectroscopy. Through the use of the gamma-resonance process theoretical analysis methods and of the equation solution method for the density matrix with the secondary quantization of gamma-radiation field one attacks the problems dealing with the effect of both variable fields and relaxation on gamma-resonance. One has studied the gamma-radiation ultrasound modulation stages. One points out a peculiar role of the gamma-magnetic resonance effect in modulation gamma resonance spectroscopy formation. One forecasts development of the modulation gamma-resonance spectroscopy into the nonlinear gamma-resonance spectroscopy

  14. Home treatment of patients with low-risk pulmonary embolism with the oral factor Xa inhibitor rivaroxaban. Rationale and design of the HoT-PE Trial.

    Science.gov (United States)

    Barco, Stefano; Lankeit, Mareike; Binder, Harald; Schellong, Sebastian; Christ, Michael; Beyer-Westendorf, Jan; Duerschmied, Daniel; Bauersachs, Rupert; Empen, Klaus; Held, Matthias; Schwaiblmair, Martin; Fonseca, Cândida; Jiménez, David; Becattini, Cecilia; Quitzau, Kurt; Konstantinides, Stavros

    2016-07-01

    Pulmonary embolism (PE) is a potentially life-threatening acute cardiovascular syndrome. However, more than 95 % of patients are haemodynamically stable at presentation, and among them are patients at truly low risk who may qualify for immediate or early discharge. The Home Treatment of Pulmonary Embolism (HoT-PE) study is a prospective international multicentre single-arm phase 4 management (cohort) trial aiming to determine whether home treatment of acute low-risk PE with the oral factor Xa inhibitor rivaroxaban is feasible, effective, and safe. Patients with confirmed PE, who have no right ventricular dysfunction or free floating thrombi in the right atrium or ventricle, are eligible if they meet none of the exclusion criteria indicating haemodynamic instability, serious comorbidity or any condition mandating hospitalisation, or a familial/social environment unable to support home treatment. The first dose of rivaroxaban is given in hospital, and patients are discharged within 48 hours of presentation. Rivaroxaban is taken for at least three months. The primary outcome is symptomatic recurrent venous thromboembolism or PE-related death within three months of enrolment. Secondary outcomes include quality of life and patient satisfaction, and health care resource utilisation compared to existing data on standard-duration hospital treatment. HoT-PE is planned to analyse 1,050 enrolled patients, providing 80 % power to reject the null hypothesis that the recurrence rate of venous thromboembolism is >3 % with α≤0.05. If the hypothesis of HoT-PE is confirmed, early discharge and out-of-hospital treatment may become an attractive, potentially cost-saving option for a significant proportion of patients with acute PE. PMID:27010343

  15. Precision calculations for gamma gamma --> WW --> 4fermions(+gamma)

    CERN Document Server

    Bredenstein, A; Roth, M

    2005-01-01

    The O(alpha) electroweak radiative corrections to gamma gamma --> WW --> 4f within the electroweak Standard Model are calculated in double-pole approximation (DPA). Virtual corrections are treated in DPA, and real-photonic corrections are based on complete lowest-order matrix elements for gamma gamma --> 4f+gamma. The radiative corrections are implemented in a Monte Carlo generator called COFFERgammagamma, which optionally includes anomalous triple and quartic gauge-boson couplings in addition and performs a convolution over realistic spectra of the photon beams. A brief survey of numerical results comprises O(alpha) corrections to integrated cross sections as well as to angular and invariant-mass distributions.

  16. The Anomalous Decay eta -> pi pi gamma gamma

    OpenAIRE

    Knoechlein, G.; Scherer, S; Drechsel, D.

    1995-01-01

    We investigate the rare radiative eta decay modes eta -> pi+ pi- gamma gamma and eta -> pi0 pi0 gamma gamma within the framework of chiral lagrangians at o(p^4) and present photon spectra for both processes.

  17. Monitoring low molecular weight heparins at therapeutic levels: dose-responses of, and correlations and differences between aPTT, anti-factor Xa and thrombin generation assays.

    Directory of Open Access Journals (Sweden)

    Owain Thomas

    Full Text Available Low molecular weight heparins (LMWH's are used to prevent and treat thrombosis. Tests for monitoring LMWH's include anti-factor Xa (anti-FXa, activated partial thromboplastin time (aPTT and thrombin generation. Anti-FXa is the current gold standard despite LMWH's varying affinities for FXa and thrombin.To examine the effects of two different LMWH's on the results of 4 different aPTT-tests, anti-FXa activity and thrombin generation and to assess the tests' concordance.Enoxaparin and tinzaparin were added ex-vivo in concentrations of 0.0, 0.5, 1.0 and 1.5 anti-FXa international units (IU/mL, to blood from 10 volunteers. aPTT was measured using two whole blood methods (Free oscillation rheometry (FOR and Hemochron Jr (HCJ and an optical plasma method using two different reagents (ActinFSL and PTT-Automat. Anti-FXa activity was quantified using a chromogenic assay. Thrombin generation (Endogenous Thrombin Potential, ETP was measured on a Ceveron Alpha instrument using the TGA RB and more tissue-factor rich TGA RC reagents.Methods' mean aPTT at 1.0 IU/mL LMWH varied between 54s (SD 11 and 69s (SD 14 for enoxaparin and between 101s (SD 21 and 140s (SD 28 for tinzaparin. ActinFSL gave significantly shorter aPTT results. aPTT and anti-FXa generally correlated well. ETP as measured with the TGA RC reagent but not the TGA RB reagent showed an inverse exponential relationship to the concentration of LMWH. The HCJ-aPTT results had the weakest correlation to anti-FXa and thrombin generation (Rs0.62-0.87, whereas the other aPTT methods had similar correlation coefficients (Rs0.80-0.92.aPTT displays a linear dose-response to LMWH. There is variation between aPTT assays. Tinzaparin increases aPTT and decreases thrombin generation more than enoxaparin at any given level of anti-FXa activity, casting doubt on anti-FXa's present gold standard status. Thrombin generation with tissue factor-rich activator is a promising method for monitoring LMWH's.

  18. Rehabilitation of gamma

    Science.gov (United States)

    Poynton, Charles A.

    1998-07-01

    Gamma characterizes the reproduction of tone scale in an imaging system. Gamma summarizes, in a single numerical parameter, the nonlinear relationship between code value--in an 8-bit system, from 0 through 255--and physical intensity. Nearly all image coding systems are nonlinear, and so involve values of gamma different from unity. Owing to poor understanding of tone scale reproduction, and to misconceptions about nonlinear coding, gamma has acquired a terrible reputation in computer graphics and image processing. In addition, the world-wide web suffers from poor reproduction of grayscale and color images, due to poor handling of nonlinear image coding. This paper aims to make gamma respectable again.

  19. Gamma-ray astronomy

    OpenAIRE

    Pohl, Martin

    2001-01-01

    This paper summarizes recents results in gamma-ray astronomy, most of which were derived with data from ground-based gamma-ray detectors. Many of the contributions presented at this conference involve multiwavelength studies which combine ground-based gamma-ray measurements with optical data or space-based X-ray and gamma-ray measurements. Besides measurements of the diffuse emission from the Galaxy, observations of blazars, gamma-ray bursts, and supernova remnants this paper also covers theo...

  20. Reactor gamma spectrometry: status

    International Nuclear Information System (INIS)

    Current work is described for Compton Recoil Gamma-Ray Spectrometry including developments in experimental technique as well as recent reactor spectrometry measurements. The current status of the method is described concerning gamma spectromoetry probe design and response characteristics. Emphasis is given to gamma spectrometry work in US LWR and BR programs. Gamma spectrometry in BR environments are outlined by focussing on start-up plans for the Fast Test Reactor (FTR). Gamma spectrometry results are presented for a LWR pressure vessel mockup in the Poolside Critical Assembly (PCA) at Oak Ridge National Laboratory

  1. Industrial 800xA系统在无缝钢管生产中的应用%Application of Industrial 800xA System in Seamless Tube Mill

    Institute of Scientific and Technical Information of China (English)

    李建军; 余志伟; 王歌; 刘占国

    2009-01-01

    Application of ABB Industrial 800xA System in Seamless Tube Mill is described,including technological process,system configuration,software function and performance analysis etc.The automation level,productivity and control accuracy in seamless tube are extremely improved by using Industrial 800xA system,stability and reliability of production are ensured as well.%介绍ABB Industrial 800xA系统在无缝钢管生产领域中的应用,主要包括工艺流程、系统配置、软件控制功能、性能分析等内容.该系统的使用显著地提高了缝钢管生产的自动化控制水平,有效地提升了生产节奏和控制精度,生产的稳定性和可靠性得到了有效保障.

  2. Gamma Splines and Wavelets

    Directory of Open Access Journals (Sweden)

    Hannu Olkkonen

    2013-01-01

    Full Text Available In this work we introduce a new family of splines termed as gamma splines for continuous signal approximation and multiresolution analysis. The gamma splines are born by -times convolution of the exponential by itself. We study the properties of the discrete gamma splines in signal interpolation and approximation. We prove that the gamma splines obey the two-scale equation based on the polyphase decomposition. to introduce the shift invariant gamma spline wavelet transform for tree structured subscale analysis of asymmetric signal waveforms and for systems with asymmetric impulse response. Especially we consider the applications in biomedical signal analysis (EEG, ECG, and EMG. Finally, we discuss the suitability of the gamma spline signal processing in embedded VLSI environment.

  3. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.;

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions of...... differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears that the...

  4. How the $\\gamma \\gamma$ Resonance Stole Christmas

    CERN Document Server

    Craig, Nathaniel; Kilic, Can; Thomas, Scott

    2015-01-01

    The experimental and theoretical implications of heavy di-gauge boson resonances that couple to, or are comprised of, new charged and strongly interacting matter are investigated. Observation and measurement of ratios of the resonant di-gauge boson channels $WW$, $ZZ$, $\\gamma \\gamma$, $Z \\gamma$, and $gg$ in the form of di-jets, provide a rather direct -- and for some ratios a rather robust -- probe of the gauge representations of the new matter. For a spin-zero resonance with the quantum numbers of the vacuum, the ratios of resonant $WW$ and $ZZ$ to $\\gamma \\gamma$ channels, as well as the longitudinal versus transverse polarization fractions in the $WW$ and $ZZ$ channels, provide extraordinarily sensitive probes for possible mixing with the Higgs boson, while di-Higgs and di-top resonant channels, $hh$ and $tt$, provide somewhat less sensitivity. We present a survey of possible underlying models for di-gauge boson resonances by considering various limits for the mass of the new charged and strongly interac...

  5. Gamma-thermoluminescence dating (GAMMA-TL)

    International Nuclear Information System (INIS)

    The experimental simplification of the TL dating method is one of the CRIAA Laboratory research fields in physics applied to archaeology. For radiochemical homogeneous systems GAMMA-TL allows a significant simplification for the measurement of the natural dose-rate I while preserving an accuracy as good as the one of classical TL dating within certain limiting circumstances. For instance, in the case of large heated structures determination of I reduces to Isub(γ) on site measurement and to k determination. The annual dose-rate is then given by I = GAMMA(k)Isub (γ) with GAMMA(k) = 12.17 k + 2.72. However, it is necessary to test the hypothesis that radioactivity in the structure is homogeneous. For this purpose high resolution γ spectrometry is used as a routine laboratory technique applied to several similar samples of structure. The comparison between the natural γ-ray criteria for the GAMMA-TL method, since for constant conditions, γ-ray intensities must be identical from one sample to another. We are now investigating structures of known age in order to find within what limits the GAMMA-TL can be used. (author)

  6. Transition Distribution Amplitudes for gamma* gamma collisions

    CERN Document Server

    Lansberg, J P; Szymanowski, L

    2008-01-01

    We study the exclusive production of pi-pi and rho-pi in hard gamma* gamma scattering in the forward kinematical region where the virtuality of one photon provides us with a hard scale in the process. The newly introduced concept of Transition Distribution Amplitudes (TDA) is used to perform a QCD calculation of these reactions thanks to two simple models for TDAs. The sizable cross sections for rho-pi and pi-pi production may be tested at intense electron-positron colliders such as CLEO and B factories (Belle and BaBar).

  7. Screening of gamma radiation-induced pathogen resistance rice lines against Xanthomonas oryzae pv. oryzae

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Chan Ju; Lee, Ha Yeon; Kim, Woong Bom; Ahmad, Raza; Moon, Jae Sun; Kwon, Suk Yoon [Korea Research Institute of Beoscience and Biotechnology, Daejeon (Korea, Republic of); Kim, Dong Sub [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-09-15

    Bacterial blight is one of the most serious diseases of rice (Oryza sativa L.), and it has been known that Xanthomonas oryzae pv. oryzae (Xoo) causes this disease symptom. To develop resistance rice cultivars against Xoo, 3,000 lines of M{sub 3}, which were irradiated with gamma ray, were tested by 'scissor-dip method' primarily, and 191 putative resistant lines were selected. In M{sub 4} generation, these lines were screened again with various ways such as measuring of symptom of bacterial blight in leaf, number of tiller, fresh weight, and phenotypic segregation ratio in next generation. Finally, six resistance lines were selected. RT-PCR analysis revealed that these lines displayed high level of R-genes such as Xa21, Pi36, and Pi-ta. These results indicate that mutations by gamma ray cause disruptions of regulatory signal transduction systems of these R-genes. Furthermore, these selected mutants could be useful for the development of rice cultivar resistant to Xoo.

  8. Screening of gamma radiation-induced pathogen resistance rice lines against Xanthomonas oryzae pv. oryzae

    International Nuclear Information System (INIS)

    Bacterial blight is one of the most serious diseases of rice (Oryza sativa L.), and it has been known that Xanthomonas oryzae pv. oryzae (Xoo) causes this disease symptom. To develop resistance rice cultivars against Xoo, 3,000 lines of M3, which were irradiated with gamma ray, were tested by 'scissor-dip method' primarily, and 191 putative resistant lines were selected. In M4 generation, these lines were screened again with various ways such as measuring of symptom of bacterial blight in leaf, number of tiller, fresh weight, and phenotypic segregation ratio in next generation. Finally, six resistance lines were selected. RT-PCR analysis revealed that these lines displayed high level of R-genes such as Xa21, Pi36, and Pi-ta. These results indicate that mutations by gamma ray cause disruptions of regulatory signal transduction systems of these R-genes. Furthermore, these selected mutants could be useful for the development of rice cultivar resistant to Xoo

  9. Moessbauer gamma echo

    International Nuclear Information System (INIS)

    By applying stepwise phase modulation of recoilless gamma radiation in a coincidence experiment, constructive interference is produced in transmission geometry between the source and the absorber fields. The resulting regenerated decay signal is called a gamma echo. Here it is demonstrated that during the decay of the 14.4 keV state of 57Fe multiple echo signals can be generated. (orig.)

  10. Gamma-ray sources

    International Nuclear Information System (INIS)

    Results are presented from an analysis of the celestial gamma-ray fine-scale structure based on over half of the data which may ultimately be available from the COS-B satellite. A catalogue consisting of 25 gamma-ray sources measured at energies above 100 MeV is presented. (Auth.)

  11. Gamma-sterilization

    International Nuclear Information System (INIS)

    The author makes a survey of his experience in sterilization and sterility control of medical products. At present three different methods are used, steamsterilization, gassterilizing and gammasterilizing. The investments and costs for gamma radiation is presented and a comparison of the costs for gamma- and gassterilization including sterility control is made. (M.S.)

  12. BUCS: Patterns and Robustness: Experimentation with Safety Patterns in Safety-Critical Software Systems

    OpenAIRE

    Ljosland, Ingvar

    2006-01-01

    In modern society, we rely on safely working software systems. This is the final report in a masters degree project to reveal key issues in the science field of computer software architecture and design of safety-critical software systems. A pre-study of a navigation system implied that functionality related problems and safety-critical problems do not stack one to one, but rather is a case of solving these aspects in different layers. This means that changes in software systems functionalit...

  13. Resolved photon and multi-component model for $\\gamma^*$p and $\\gamma^* \\gamma^*$ total cross section

    OpenAIRE

    Szczurek, A.; Pietrycki, T.

    2005-01-01

    We generalize our previous model for $\\gamma^* p$ scattering to $\\gamma \\gamma$ scattering. Performing a new simultaneous fit to $\\gamma^* p$ and $\\gamma \\gamma$ total cross section we find an optimal set of parameters to describe both processes. We propose new measures of factorization breaking for $\\gamma^* \\gamma^*$ collisions and present results for our new model.

  14. Colliding. gamma. e- and. gamma gamma. -beams on the basis of electron-positron linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, I.F.; Kotkin, G.L.; Serbo, V.G.; Tel' nov, V.I.

    1983-08-01

    Main properties of the ..gamma..e and ..gamma gamma.. collisions are discussed in some detail with application to the generation of colliding ..gamma..e and ..gamma gamma.. beams basing on the designed linear accelerators with colliding e/sup +/e/sup -/ beams, VLEEP and SLC, as it was proposed in a previous work. Intensive ..gamma.. beams with the energy 50 GeV would be produced from scattering of the laser light focused to the electron beams of the accelerators. Laser radiation is focused to the electron beam in the conversion region at a distance of about 10 cm from the place of collision. After scattering on electrons high-energy photons move practically along the electron primary trajectories and are focused in the collision region. The electrons are deflected from the collision region by means of approximately 1 T magnetic field. Then the produced ..gamma..-beam collides with an electron beam or a similar ..gamma..-beam. In the case when the maximum luminosity (L) is attained, the luminosity distribution in the invariant mass of the ..gamma..e or ..gamma gamma.. systems is wide. A monochromatization of the collisions up to the level of 5-10% is possible. That will entail a decrease in the luminosity, the procedure is most effective if one uses the electrons and the laser photons with opposite helicities. Examples of physically interesting problems to be investigated with the proposed ..gamma..e and ..gamma gamma.. beams are suggested.

  15. Two inert scalar doublet model and $h \\to \\gamma \\gamma,\\gamma Z$ at LHC

    CERN Document Server

    Fortes, E C F S; Montaño, J; Pleitez, V

    2014-01-01

    We consider the decays $h\\to\\gamma\\gamma,\\gamma Z$ in the context of a model with two inert Higgs doublets, once there are contributions to these processes through charged scalars in loops. We found that when considering the more precise available experimental data for $h\\to\\gamma\\gamma$ and the correlation between both channels, the enhancement for $h\\to\\gamma Z$ can not be larger than twice the standard model prediction.

  16. GammaWorkshops Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramebaeck, H. (ed.) (Swedish Defence Research Agency (Sweden)); Straalberg, E. (Institute for Energy Technology, Kjeller (Norway)); Klemola, S. (Radiation and Nuclear Safety Authority, STUK (Finland)); Nielsen, Sven P. (Technical Univ. of Denmark. Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Palsson, S.E. (Icelandic Radiation Safety Authority (Iceland))

    2012-01-15

    Due to a sparse interaction during the last years between practioners in gamma ray spectrometry in the Nordic countries, a NKS activity was started in 2009. This GammaSem was focused on seminars relevant to gamma spectrometry. A follow up seminar was held in 2010. As an outcome of these activities it was suggested that the 2011 meeting should be focused on practical issues, e.g. different corrections needed in gamma spectrometric measurements. This three day's meeting, GammaWorkshops, was held in September at Risoe-DTU. Experts on different topics relevant for gamma spectrometric measurements were invited to the GammaWorkshops. The topics included efficiency transfer, true coincidence summing corrections, self-attenuation corrections, measurement of natural radionuclides (natural decay series), combined measurement uncertainty calculations, and detection limits. These topics covered both lectures and practical sessions. The practical sessions included demonstrations of tools for e.g. corrections and calculations of the above meantioned topics. (Author)

  17. Gamma-ray Astronomy

    CERN Document Server

    Hinton, Jim

    2007-01-01

    The relevance of gamma-ray astronomy to the search for the origin of the galactic and, to a lesser extent, the ultra-high-energy cosmic rays has long been recognised. The current renaissance in the TeV gamma-ray field has resulted in a wealth of new data on galactic and extragalactic particle accelerators, and almost all the new results in this field were presented at the recent International Cosmic Ray Conference (ICRC). Here I summarise the 175 papers submitted on the topic of gamma-ray astronomy to the 30th ICRC in Merida, Mexico in July 2007.

  18. The gamma function

    CERN Document Server

    Artin, Emil

    2015-01-01

    This brief monograph on the gamma function was designed by the author to fill what he perceived as a gap in the literature of mathematics, which often treated the gamma function in a manner he described as both sketchy and overly complicated. Author Emil Artin, one of the twentieth century's leading mathematicians, wrote in his Preface to this book, ""I feel that this monograph will help to show that the gamma function can be thought of as one of the elementary functions, and that all of its basic properties can be established using elementary methods of the calculus."" Generations of teachers

  19. GammaWorkshops Proceedings

    DEFF Research Database (Denmark)

    Strålberg, Elisabeth; Klemola, Seppo; Nielsen, Sven Poul;

    were invited to the GammaWorkshops. The topics included efficiency transfer, true coincidence summing corrections, self-attenuation corrections, measurement of natural radionuclides (natural decay series), combined measurement uncertainty calculations, and detection limits. These topics covered both...

  20. Gamma-ray astronomy

    Science.gov (United States)

    Ramaty, R.; Lingenfelter, R. E.

    1982-01-01

    Cosmic gamma rays, the physical processes responsible for their production and the astrophysical sites from which they were seen are reported. The bulk of the observed gamma ray emission is in the photon energy range from about 0.1 MeV to 1 GeV, where observations are carried out above the atmosphere. There are also, however, gamma ray observations at higher energies obtained by detecting the Cerenkov light produced by the high energy photons in the atmosphere. Gamma ray emission was observed from sources as close as the Sun and the Moon and as distant as the quasar 3C273, as well as from various other galactic and extragalactic sites. The radiation processes also range from the well understood, e.g. energetic particle interactions with matter, to the still incompletely researched, such as radiation transfer in optically thick electron positron plasmas in intense neutron star magnetic fields.

  1. Gamma ray camera

    International Nuclear Information System (INIS)

    An improved Anger-type gamma ray camera utilizes a proximity-type image intensifier tube. It has a greater capability for distinguishing between incident and scattered radiation, and greater spatial resolution capabilities

  2. Dynamic gamma knife radiosurgery

    International Nuclear Information System (INIS)

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C(TM) and Perfexion(TM) units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and

  3. Gamma ray optics

    Energy Technology Data Exchange (ETDEWEB)

    Jentschel, M.; Guenther, M. M.; Habs, D.; Thirolf, P. G. [Institut Laue-Langevin, F38042 Grenoble (France); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching, Germany and Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany); Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany)

    2012-07-09

    Via refractive or diffractive scattering one can shape {gamma} ray beams in terms of beam divergence, spot size and monochromaticity. These concepts might be particular important in combination with future highly brilliant gamma ray sources and might push the sensibility of planned experiments by several orders of magnitude. We will demonstrate the experimental feasibility of gamma ray monochromatization on a ppm level and the creation of a gamma ray beam with nanoradian divergence. The results are obtained using the inpile target position of the High Flux Reactor of the ILL Grenoble and the crystal spectrometer GAMS. Since the refractive index is believed to vanish to zero with 1/E{sup 2}, the concept of refractive optics has never been considered for gamma rays. The combination of refractive optics with monochromator crystals is proposed to be a promising design. Using the crystal spectrometer GAMS, we have measured for the first time the refractive index at energies in the energy range of 180 - 2000 keV. The results indicate a deviation from simple 1/E{sup 2} extrapolation of X-ray results towards higher energies. A first interpretation of these new results will be presented. We will discuss the consequences of these results on the construction of refractive optics such as lenses or refracting prisms for gamma rays and their combination with single crystal monochromators.

  4. The Polarization Dependence of Gamma-Gamma Absorption - Implications for Gamma-Ray Bursts and Blazars

    CERN Document Server

    Boettcher, Markus

    2014-01-01

    This paper presents an analysis of the dependence of the opacity for high-energy gamma-rays to gamma-gamma absorption by low-energy photons, on the polarization of the gamma-ray and target photons. This process has so far only been considered using the polarization-averaged gamma-gamma absorption cross section. It is demonstrated that in the case of polarized gamma-ray emission, subject to source-intrinsic gamma-gamma absorption by polarized target photons, this may lead to a slight over-estimation of the gamma-gamma opacity by up to ~ 10 % in the case of a perfectly ordered magnetic field. Thus, for realistic astrophysical scenarios with partially ordered magnetic fields, the use of the polarization-averaged gamma-gamma cross section is justified for practical purposes, such as estimates of minimum Doppler factors inferred for gamma-ray bursts and blazars, based on gamma-gamma transparency arguments, and this paper quantifies the small error incurred by the unpolarized-radiation approximation. Furthermore, i...

  5. Characterizations of {\\Gamma}-AG^{**}-groupoids by their {\\Gamma}-ideals

    CERN Document Server

    Khan, Madad

    2010-01-01

    In this paper we have discusses {\\Gamma}-left, {\\Gamma}-right, {\\Gamma}-bi-, {\\Gamma}-quasi-, {\\Gamma}-interior and {\\Gamma}-ideals in {\\Gamma}-AG^{**}-groupoids and regular {\\Gamma}-AG^{**}-groupoids. Moreover we have proved that the set of {\\Gamma}-ideals in a regular {\\Gamma}-AG^{**}-groupoid form a semilattice structure. Also we have characterized a regular {\\Gamma}-AG^{**}-groupoid in terms of left ideals.

  6. Characterizations of gamma-AG^{**}-groupoids by the properties their gamma-ideals

    OpenAIRE

    Khan, Madad; Ahmad, Naveed; Rehman, Inayatur

    2010-01-01

    In this paper we have discusses {\\Gamma}-left, {\\Gamma}-right, {\\Gamma}-bi-, {\\Gamma}-quasi-, {\\Gamma}-interior and {\\Gamma}-ideals in {\\Gamma}-AG^{**}-groupoids and regular {\\Gamma}-AG^{**}-groupoids. Moreover we have proved that the set of {\\Gamma}-ideals in a regular {\\Gamma}-AG^{**}-groupoid form a semilattice structure. Also we have characterized a regular {\\Gamma}-AG^{**}-groupoid in terms of left ideals.

  7. Measurement of anomalous couplings ZZ gamma , Z gamma gamma and ZZZ

    CERN Document Server

    Matteuzzi, C

    2001-01-01

    The anomalous couplings Z gamma gamma , ZZ gamma and ZZZ have been studied at LEP 2 with the reactions e/sup +/e/sup -/ to qq gamma , e /sup +/e/sup -/ to nu nu gamma and e/sup +/e/sup to / ZZ at square root s from 189 to 202 GeV. Limits are derived on three gauge neutral bosons couplings combining the results of the 3 experiments L3, OPAL and DELPHI.

  8. Observation of the Decay $K^{+} \\rightarrow \\pi^{+}\\gamma\\gamma$

    CERN Document Server

    Kitching, P; Rozon, M; Soluk, R A; Adler, Stephen Louis; Atiya, M S; Chiang, I H; Frank, J S; Haggerty, J S; Kycia, T F; Li Kai Kong; Littenberg, L S; Sambamurti, A K; Stevens, A; Strand, R C; Witzig, C; Louis, W C; Akerib, D S; Ardebili, M; Convery, M; Ito, M M; Marlow, D R; McPherson, R A; Meyers, P D; Selen, M A; Shoemaker, F C; Smith, A J S; Blackmore, E W; Bryman, D A; Felawka, L; Konaka, A; Kuno, Y; MacDonald, J A; Numao, T; Padley, P; Poutissou, J M; Poutissou, R; Roy, J D; Turcot, A S

    1997-01-01

    The first observation of the decay K^+ --> pi^+ gamma gamma is reported. A total of 31 events was observed with an estimated background of 5.2 +- 3.3 events in the pi+ momentum range from 100 MeV/c to 180 MeV/c. The corresponding partial branching ratio, B(K+ -> pi+ gamma gamma, 100 MeV/c pi^+ gamma gamma decay was observed in the pi^+ momentum region greater than 215 MeV/c. The observed pi^+ momentum spectrum is compared with the predictions of chiral perturbation theory.

  9. Observation of the Decay K^+ --> pi^+ gamma gamma

    OpenAIRE

    E791 Collaboration; Kitching, P.; Nakano, T.; Rozon, M.; Soluk, R.; Adler, S.; Atiya, M. S.; Chiang, I-H.; Frank, J. S.; Haggerty, J. S.; Kycia, T. F.; Li, K. K.; Littenberg, L. S.; Sambamurti, A.; Stevens, A.

    1997-01-01

    The first observation of the decay K^+ --> pi^+ gamma gamma is reported. A total of 31 events was observed with an estimated background of 5.1 +- 3.3 events in the pi+ momentum range from 100 MeV/c to 180 MeV/c. The corresponding partial branching ratio, B(K+ -> pi+ gamma gamma, 100 MeV/c pi^+ gamma gamma decay was observed in the pi^+ momentum region greater than 215 MeV/c. The observed pi^+ momentum spectrum is...

  10. Gamma Ray Bursts

    Science.gov (United States)

    Gehrels, Neil; Meszaros, Peter

    2012-01-01

    Gamma-ray bursts (GRBs) are bright flashes of gamma-rays coming from the cosmos. They occur roughly once per day ,last typically lOs of seconds and are the most luminous events in the universe. More than three decades after their discovery, and after pioneering advances from space and ground experiments, they still remain mysterious. The launch of the Swift and Fermi satellites in 2004 and 2008 brought in a trove of qualitatively new data. In this review we survey the interplay between these recent observations and the theoretical models of the prompt GRB emission and the subsequent afterglows.

  11. Gamma-Ray Bursts

    Science.gov (United States)

    Gehrels, Neil; Mészáros, Péter

    2012-08-01

    Gamma-ray bursts (GRBs) are bright flashes of gamma rays coming from the cosmos. They occur roughly once per day, typically last for tens of seconds, and are the most luminous events in the universe. More than three decades after their discovery, and after pioneering advances from space and ground experiments, they still remain mysterious. The launch of the Swift and Fermi satellites in 2004 and 2008 brought in a trove of qualitatively new data. In this Review, we survey the interplay between these recent observations and the theoretical models of the prompt GRB emission and the subsequent afterglow.

  12. Gamma Ray Bursts

    CERN Document Server

    Gehrels, Neil; 10.1126/science.1216793

    2012-01-01

    Gamma-ray bursts (GRBs) are bright flashes of gamma-rays coming from the cosmos. They occur roughly once per day, last typically 10s of seconds and are the most luminous events in the universe. More than three decades after their discovery, and after pioneering advances from space and ground experiments, they still remain mysterious. The launch of the Swift and Fermi satellites in 2004 and 2008 brought in a trove of qualitatively new data. In this review we survey the interplay between these recent observations and the theoretical models of the prompt GRB emission and the subsequent afterglows.

  13. SVOM gamma ray monitor

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The space-based multi-band astronomical Variable Object Monitor(SVOM) mission is dedicated to the detection,localization and broad-band study of gamma-ray bursts(GRBs) and other high-energy transient phenomena.The gamma ray monitor(GRM) onboard is designed to observe GRBs up to 5 MeV.With this instrument,one of the key GRB parameters,Epeak,can be easily measured in the hard X-ray band.It can achieve a detection rate of 100 GRBs per year which ensures the scientific output of SVOM.

  14. 体积排阻色谱法测定低分子量肝素抗凝血因子Xa的活性%An assay for anti-factor Xa activity of low molecular weight heparins by high performance liquid size exclusion chromatography

    Institute of Scientific and Technical Information of China (English)

    张倩倩; 康经武

    2013-01-01

    发展了一种基于体积排阻色谱测定低分子量肝素(LMWH)抗凝血活性的方法.利用肝素与抗凝血酶Ⅲ(ATⅢ)结合后可增强ATⅢ对凝血因子Xa (FXa)抑制作用的原理,通过测定加入LMWH后FXa水解其生色底物产生对硝基苯胺(pNA)这一反应的抑制程度确定LMWH的活性.首先将含有一定浓度LMWH的缓冲溶液与ATⅢ溶液混合,然后依次加入FXa和生色底物,分别孵育一段时间.底物被FXa水解,产生游离的pNA.体积排阻色谱可将小分子产物pNA与其他大分子分离开,因而可以在pNA的最大吸收波长下得到高灵敏度的测定,并且不再受其他成分的干扰.该方法重复性好,灵敏度高,极大地减少了样品的消耗量,降低了成本,并且还可进行各种复杂样品(如血浆)中LMWH抗FXa活性的监测.%The "gold standard" assay for monitoring low molecular weight heparins (LMWHs) activity is the chromogenic-based anti-factor Xa assay.The methodology of an anti-factor Xa assay is that LMWH is added to a known amount of excess factor Xa and excess antithrombin.It will bind to antithrombin and form a triplet complex with factor Xa,inhibiting the activity of factor Xa.However,the residual factor Xa can still hydrolyze chromogenic peptide substrate,releasing the chromophore for photometric detection.The absorbance is inversely proportional to the amount of heparin/LMWH.The results are given in anticoagulant concentration in units/ mL of anti-factor Xa,such that high values indicate high levels of anticoagulation and low values indicate low levels of anticoagulation.Herein,a novel assay method for anti-FXa activity of LMWHs using high performance liquid size exclusion chromatography (SEC) is reported,in which antithrombin m (AT m) was diluted by the buffer solution contained LMWHs.Subsequently,exogenous FXa and p-nitroaniline coupled peptide substrate were added and incubated for a period,separately.The resulting mixture was separated based on size by SEC

  15. CKM angle $\\gamma$ from LHCb

    CERN Multimedia

    Smith, Jackson

    2015-01-01

    Results of the latest $\\gamma$ combination from LHCb are presented, along with the six LHCb measurements used as inputs. In addition, the anticipated precision attainable for measuring $\\gamma$ after the LHCb Upgrade is outlined

  16. Combinatorics of $\\gamma$-structures

    CERN Document Server

    Han, Hillary S W

    2011-01-01

    In this paper we study canonical $\\gamma$-structures, a class of RNA pseudoknot structures that plays a key role in the context of polynomial time folding of RNA pseudoknot structures. A $\\gamma$-structure is composed by specific building blocks, that have topological genus less than or equal to $\\gamma$, where composition means concatenation and nesting of such blocks. Our main result is the derivation of the generating function of $\\gamma$-structures via symbolic enumeration. $\\gamma$-structures are constructed via $\\gamma$-matchings. We compute an algebraic equation for the generating function of these matchings and prove that it is the unique solution. For $\\gamma=1$ and $\\gamma=2$ we compute the Puiseux-expansion of this power series at its unique, dominant singularity. This allows us to derive simple asymptotic formulas for the number of 1-structures and 2-structures.

  17. Interferon Gamma-1b Injection

    Science.gov (United States)

    Interferon gamma-1b injection is used to reduce the frequency and severity of serious infections in people ... with severe, malignant osteopetrosis (an inherited bone disease). Interferon gamma-1b is in a class of medications ...

  18. Gamma cardio 82

    International Nuclear Information System (INIS)

    New trends in nuclear cardiology are briefly presented supported by a large bibliography. The following topics are reviewed: new tracers of myocardial perfusion and metabolism; quantitative analysis of cardiac function; nuclear stethoscope; gamma emission tomography; diagnostic value of cardiac dynamic tests (at rest and during exercise), pharmacological tests; new clinical applications of cardiovascular nuclear medicine

  19. Ultrasonography X gamma radiography

    International Nuclear Information System (INIS)

    The accumulated experience in the last ten years of substitution to essays by gamma radiography to essay by ultrasonography, starting of the systematic comparison and tabulation of the results obtained by both essays applied in welding joints, in field, in steel pipelines of the SABESP. (V.R.B.)

  20. Introscopy using gamma sources

    International Nuclear Information System (INIS)

    A method is described of working with standard 170Tm, 75Se, 192Ir, 137Cs and 60Co sources at the activity of 1-4000 Ci, during television gamma introscopy of steel products. Experiments involving the RI-10T introscope are carried out to determine prospects of using various radiation sources. The results of using X-ray instruments for control of steel products are also shown for comparison. In introscopy of X-rayed steel products over 25 mm thick, spreading of the edge of the detected groove image is shown to be comparable when using X radiation and gamma radiation of standard sources. Sensitivity of control by fluorographic introscope in X-raying and gamma irradiation of products over 25 mm thick will presumably be the same owing to the detector storage capacity. The use of commercial gamma flaw detecting instruments together with a television introscope permits to reliably reveal defects of 0.5-2.0 mm in size, eliminating possible instability of operation of X-ray instruments, particularly in field conditions

  1. Industrial radiography. Gamma radiography

    International Nuclear Information System (INIS)

    Informations are given on gamma radiodefectology regulations, entire references and main dispositions applicable to each state of the European Economic Community. The content includes previous arrangements for source acquisition, holding and use of the sources, transport, accidents, civil liability of the source holder, person insurance against radiation hazards and contamination, property insurance, penal liability of the source holder

  2. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, Sidse M; Hansen, Lars Kai; Parnas, Josef;

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able to...

  3. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.; Mørup, Morten

    2007-01-01

    evoke gamma oscillations. EEG was recorded using 64 channels in 14 healthy subjects. In each of three runs a stimulus of 100 g load increment in each hand was presented in 120 trials. Data were wavelet transformed and runs collapsed. Inter-trial phase coherence (ITPC) was computed as the best measure of...

  4. Chemist's gamma-ray table

    International Nuclear Information System (INIS)

    An edited listing of gamma-ray information has been prepared. Prominent gamma rays originating from nuclides with half lives long enough to be seen in radiochemical experiments are included. Information is ordered by nuclide in one section and by energy in a second section. This shorter listing facilitates identification of nuclides responsible for gamma rays observed in experiments

  5. Comparative physical mapping of rice BAC clones linked to resistance genes Glh,Bph-3 and xa-5 in Oryza sativa L.and O.granulata Nees et Am.ex Watt.

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhiyong; TAN Guangxuan; YOU Aiqing; HE Guangyuan; SHE Chaowen; LI Lijia; SONG Yunchun

    2004-01-01

    Oryza granulata Nees et Arn. ex Watt. is one of the three wild relatives of rice, which are the most valuable for study and utilization in China. In this study, the homology and physical locations of three rice resistance genes, Glh,Bph-3 and xa-5 are comparatively analyzed between O. sativa and O. granulata by Southern blotting and fluorescence in situ hybridization (FISH). The results of Southern blotting indicate that there exist homologous sequences of the tested RFLP markers in O. granulata. By using three bacterial artificial chromosome (BAC) clones scanned by the tested RFLP as probes, FISH signals are detected on both mitotic and pachytene chromosomes in O. sativa and O. granulata.Dual-color FISH demonstrates that two of the three BAC clones (14E16 and 38J9) are located on the short arm of the same chromosome pair in O. granulata. Additionally, colinearity is shown for the two clones between O. sativa and O.granulata. Another BAC clone 44B4 is located on the end of the short arm of other chromosome pair in these two species.Although the phylogenetic relationship between O. sativa and O. granulata is the most distinct in Oryza and these two species have evidently different biological features and ecological habits, the relative lengths and arm ratios of the detected chromosomes and the relative positions of the tested clone signals on chromosomes in O. granulata are quite similar to those in O. sativa.

  6. Gamma-gamma collider based on Compton back-scattering

    International Nuclear Information System (INIS)

    A γγ collider would extend and complement the physics capability of a linear collider; e.g. it would be suitable for direct measurement of the partial decay width of a Higgs boson into two gamma quanta. This paper discusses choice of laser parameters, luminosity optimization, electron and laser parameters for a gamma- gamma collider as a second interaction region for the Next Linear Collider, laser path, and the lasers. It is concluded that a gamma- gamma collider is technically feasible; however it will require a significant investment in preparatory R ampersand D

  7. Measurement of {\\eta} meson production in {\\gamma}{\\gamma} interactions and {\\Gamma}({\\eta}-->{\\gamma}{\\gamma}) with the KLOE detector

    CERN Document Server

    :,; Badoni, D; Balwierz-Pytko, I; Bencivenni, G; Bini, C; Bloise, C; Bossi, F; Branchini, P; Budano, A; Balkestaahl, L Caldeira; Capon, G; Ceradini, F; Ciambrone, P; Czerwinski, E; Dane, E; De Lucia, E; De Robertis, G; De Santis, A; Di Domenico, A; Di Donato, C; Di Salvo, R; Domenici, D; Erriquez, O; Fanizzi, G; Fantini, A; Felici, G; Fiore, S; Franzini, P; Gauzzi, P; Giardina, G; Giovannella, S; Gonnella, F; Graziani, E; Happacher, F; Heijkenskj, L; Hoistad, B; Iafolla, L; Jacewicz, M; Johansson, T; Kupsc, A; Lee-Franzini, J; Leverington, B; Loddo, F; Loffredo, S; Mandaglio, G; Martemianov, M; Martini, M; Mascolo, M; Messi, R; Miscetti, S; Morello, G; Moricciani, D; Moskal, P; Nguyen, F; Passeri, A; Patera, V; Longhi, I Prado; Ranieri, A; Redmer, C F; Santangelo, P; Sarra, I; Schioppa, M; Sciascia, B; Silarski, M; Taccini, C; Tortora, L; Venanzoni, G; Wislicki, W; Wolke, M; Zdebik, J

    2012-01-01

    We present a measurement of {\\eta} meson production in photon-photon interactions produced by electron-positron beams colliding with \\sqrt{s}=1 GeV. The measurement is done with the KLOE detector at the \\phi-factory DA{\\Phi}NE with an integrated luminosity of 0.24 fb^{-1}. The e^+e^- --> e^+e^-{\\eta} cross section is measured without detecting the outgoing electron and positron, selecting the decays {\\eta}-->{\\pi}^+{\\pi}^-{\\pi}^0 and {\\eta}-->{\\pi}^0{\\pi}^0{\\pi}^0. The most relevant background is due to e^+e^- --> {\\eta}{\\gamma} when the monochromatic photon escapes detection. The cross section for this process is measured as {\\sigma}(e^+e^- -->{\\eta}{\\gamma}) = (856 \\pm 8_{stat} \\pm 16_{syst}) pb. The combined result for the e^+e^- -->e^+e^-{\\eta} cross section is {\\sigma}(e^+e^- -->e^+e^-{\\eta}) = (32.72 \\pm 1.27_{stat} \\pm 0.70_{syst}) pb. From this we derive the partial width {\\Gamma}({\\eta}-->{\\gamma}{\\gamma}) = (520 \\pm 20_{stat} \\pm 13_{syst}) eV. This is in agreement with the world average and is the ...

  8. Discovery of 1-(4-Methoxyphenyl)-7-oxo-6-(4-(2-oxopiperidin-1-yl)phenyl)-4,5,6,7-tetrahydro- 1H-pyrazolo[3,4-c]pyridine-3-carboxamide (Apixaban, BMS-562247), a Highly Potent, Selective, Efficacious, and Orally Bioavailable Inhibitor of Blood Coagulation Factor Xa

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Donald J.P.; Orwat, Michael J.; Koch, Stephanie; Rossi, Karen A.; Alexander, Richard S.; Smallwood, Angela; Wong, Pancras C.; Rendina, Alan R.; Luettgen, Joseph M.; Knabb, Robert M.; He, Kan; Xin, Baomin; Wexler, Ruth R.; Lam, Patrick Y.S. (BMS)

    2010-03-08

    Efforts to identify a suitable follow-on compound to razaxaban (compound 4) focused on modification of the carboxamido linker to eliminate potential in vivo hydrolysis to a primary aniline. Cyclization of the carboxamido linker to the novel bicyclic tetrahydropyrazolopyridinone scaffold retained the potent fXa binding activity. Exceptional potency of the series prompted an investigation of the neutral P{sub 1} moieties that resulted in the identification of the p-methoxyphenyl P{sub 1}, which retained factor Xa binding affinity and good oral bioavailability. Further optimization of the C-3 pyrazole position and replacement of the terminal P{sub 4} ring with a neutral heterocycle culminated in the discovery of 1-(4-methoxyphenyl)-7-oxo-6-(4-(2-oxopiperidin-1-yl)phenyl)-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine-3-carboxamide (apixaban, compound 40). Compound 40 exhibits a high degree of fXa potency, selectivity, and efficacy and has an improved pharmacokinetic profile relative to 4.

  9. The $\\gamma^* \\gamma^*\\to\\eta_c$ transition form factor

    CERN Document Server

    Lucha, Wolfgang

    2012-01-01

    We study the $\\gamma^* \\gamma^*\\to\\eta_c$ transition form factor, $F_{\\eta_c\\gamma\\gamma}(Q_1^2,Q_2^2),$ with the local-duality (LD) version of QCD sum rules. We analyse the extraction of this quantity from two different correlators, $$ and $,$ with $P,$ $A,$ and $V$ being the pseudoscalar, axial-vector, and vector currents, respectively. The QCD factorization theorem for $F_{\\eta_c\\gamma\\gamma}(Q_1^2,Q_2^2)$ allows us to fix the effective continuum thresholds for the $$ and $$ correlators at large values of $Q^2=Q_2^2$ and some fixed value of $\\beta\\equiv Q_1^2/Q_2^2$. We give arguments that, in the region $Q^2\\ge10$--$15 GeV^2$, the effective threshold should be close to its asymptotic value such that the LD sum rule provides reliable predictions for $F_{\\eta_c\\gamma\\gamma}(Q_1^2,Q_2^2).$ We show that, for the experimentally relevant kinematics of one real and one virtual photon, the result of the LD sum rule for $F_{\\eta_c\\gamma}(Q^2)\\equiv F_{\\eta_c\\gamma\\gamma}(0,Q^2)$ may be well approximated by the sim...

  10. The finite mass calculations for Gamma Gamma --> L+ L- Gamma process

    OpenAIRE

    Makarenko, V. V.; T.V. Shishkina

    2003-01-01

    The process $\\gamma\\gamma\\to l^+ l^- \\gamma$ will be used for the photon beams luminosity measurement when the total angular momentum of colliding photons equals zero. The previous studies of this process were performed in the chiral limit. But the mass contribution should be taken into account.

  11. Gamma-gamma physics and transition form factor measurements at KLOE/KLOE-2

    CERN Document Server

    Gauzzi, Paolo

    2015-01-01

    The KLOE results on the measurement of the transition form factors of the eta and pi0 mesons in phi Dalitz decays are presented, and the determination of the Gamma(eta->gamma gamma) in gamma gamma processes is also reported. The prospects for gamma gamma physics of the new data-taking, started in November 2014 with the upgraded detector, are reviewed.

  12. Novel gamma cameras

    International Nuclear Information System (INIS)

    The gamma-ray cameras described are based on radiation imaging devices which permit the direct recording of the distribution of radioactive material from a radiative source, such as a human organ. They consist in principle of a collimator, a converter matrix converting gamma photons to electrons, and an electron image multiplier producing a multiplied electron output, and means for reading out the information. The electron image multiplier is a device which produces a multiplied electron image. It can be in principle, either gas avalanche electron multiplier or a multi-channel plate. The multi-channel plate employed is a novel device, described elsewhere. The three described embodiments, in which the converter matrix can be either of metal type or of scintillation crystal type, were designed and are being developed

  13. Gamma rays in thunderstorms

    International Nuclear Information System (INIS)

    Not only lightning occur in thunderstorms but also luminous flashes that are emitted upwards over the clouds. These flashes have been studied for 20 years. Satellites have detected gamma flashes with an energy of 30 MeV. It was thought that these flashes resulted from collisions between cosmic particles and cloud molecules but recent results from the Italian Agile satellite question this explanation. Gamma flashes with an energy of 100 MeV have been detected which is too high an energy to be explained by collisions with cosmic particles. Another result show the existence of very strong acceleration of electrons in areas where some type of flashes are likely to happen. (A.C.)

  14. Gamma ray beam transmutation

    International Nuclear Information System (INIS)

    We have proposed a new approach to nuclear transmutation by a gamma ray beam of Compton scattered laser photon. We obtained 20 MeV gamma ray in this way to obtain transmutation rates with the giant resonance of 197Au and 129Iodine. The rate of the transmutation agreed with the theoretical calculation. Experiments on energy spectrum of positron, electron and neutron from targets were performed for the energy balance and design of the system scheme. The reaction rate was about 1.5∼4% for appropriate photon energies and neutron production rate was up to 4% in the measurements. We had stored laser photon more than 5000 times in a small cavity which implied for a significant improvement of system efficiency. Using these technologies, we have designed an actual transmutation system for 129Iodine which has a 16 million year's activity. In my presentation, I will address the properties of this scheme, experiments results and transmutation system for iodine transmutation

  15. Gamma ray camera

    International Nuclear Information System (INIS)

    An Anger gamma ray camera is improved by the substitution of a gamma ray sensitive, proximity type image intensifier tube for the scintillator screen in the Anger camera. The image intensifier tube has a negatively charged flat scintillator screen, a flat photocathode layer, and a grounded, flat output phosphor display screen, all of which have the same dimension to maintain unit image magnification; all components are contained within a grounded metallic tube, with a metallic, inwardly curved input window between the scintillator screen and a collimator. The display screen can be viewed by an array of photomultipliers or solid state detectors. There are two photocathodes and two phosphor screens to give a two stage intensification, the two stages being optically coupled by a light guide. (author)

  16. Optical and Gamma Superradiance

    Energy Technology Data Exchange (ETDEWEB)

    Samartsev, V. V., E-mail: samartsev@kfti.knc.ru; Kalachev, A. A. [Kazan Physical-Technical Institute of Russian Academy of Sciences (Russian Federation)

    2001-07-15

    Experiments on the observation of optical superradiance in a LaF{sub 3}:Pr{sup 3+} crystal are described. The multipulse regime of excitation of optical superradiance in both two- and multilevel systems is theoretically investigated. It is demonstrated that this regime is the generalization of the triggering regime of superradiance excitation. The developed formalism is used for the description of gamma superradiance.

  17. Nucleolar gamma-tubulin

    Czech Academy of Sciences Publication Activity Database

    Hořejší, Barbora; Marková, Vladimíra; Vinopal, Stanislav; Richterová, Věra; Dráberová, Eduarda; Sulimenko, Vadym; Philimonenko, Anatoly; Hozák, Pavel; Katsetos, C.D.; Dráber, Pavel

    Shanghai : CSBMB (The Chinese Society of Biochemistry and Molecular Biology ), 2009. s. 86-86. [IUMB /21./ and FAOBMB International congress of Biochemistry and Molecular Biology /12./. 02.04.2009-07.04.2009, shanghai] R&D Projects: GA AV ČR KAN200520701; GA MŠk LC545 Institutional research plan: CEZ:AV0Z50520514 Keywords : gamma-tubulin * nucleolus Subject RIV: EB - Genetics ; Molecular Biology

  18. Gamma camera system

    International Nuclear Information System (INIS)

    A detailed description is given of a novel gamma camera which is designed to produce superior images than conventional cameras used in nuclear medicine. The detector consists of a solid state detector (e.g. germanium) which is formed to have a plurality of discrete components to enable 2-dimensional position identification. Details of the electronic processing circuits are given and the problems and limitations introduced by noise are discussed in full. (U.K.)

  19. The DRAGO gamma camera

    International Nuclear Information System (INIS)

    In this work, we present the results of the experimental characterization of the DRAGO (DRift detector Array-based Gamma camera for Oncology), a detection system developed for high-spatial resolution gamma-ray imaging. This camera is based on a monolithic array of 77 silicon drift detectors (SDDs), with a total active area of 6.7 cm2, coupled to a single 5-mm-thick CsI(Tl) scintillator crystal. The use of an array of SDDs provides a high quantum efficiency for the detection of the scintillation light together with a very low electronics noise. A very compact detection module based on the use of integrated readout circuits was developed. The performances achieved in gamma-ray imaging using this camera are reported here. When imaging a 0.2 mm collimated 57Co source (122 keV) over different points of the active area, a spatial resolution ranging from 0.25 to 0.5 mm was measured. The depth-of-interaction capability of the detector, thanks to the use of a Maximum Likelihood reconstruction algorithm, was also investigated by imaging a collimated beam tilted to an angle of 45 deg. with respect to the scintillator surface. Finally, the imager was characterized with in vivo measurements on mice, in a real preclinical environment.

  20. The DRAGO gamma camera

    Science.gov (United States)

    Fiorini, C.; Gola, A.; Peloso, R.; Longoni, A.; Lechner, P.; Soltau, H.; Strüder, L.; Ottobrini, L.; Martelli, C.; Lui, R.; Madaschi, L.; Belloli, S.

    2010-04-01

    In this work, we present the results of the experimental characterization of the DRAGO (DRift detector Array-based Gamma camera for Oncology), a detection system developed for high-spatial resolution gamma-ray imaging. This camera is based on a monolithic array of 77 silicon drift detectors (SDDs), with a total active area of 6.7 cm2, coupled to a single 5-mm-thick CsI(Tl) scintillator crystal. The use of an array of SDDs provides a high quantum efficiency for the detection of the scintillation light together with a very low electronics noise. A very compact detection module based on the use of integrated readout circuits was developed. The performances achieved in gamma-ray imaging using this camera are reported here. When imaging a 0.2 mm collimated C57o source (122 keV) over different points of the active area, a spatial resolution ranging from 0.25 to 0.5 mm was measured. The depth-of-interaction capability of the detector, thanks to the use of a Maximum Likelihood reconstruction algorithm, was also investigated by imaging a collimated beam tilted to an angle of 45° with respect to the scintillator surface. Finally, the imager was characterized with in vivo measurements on mice, in a real preclinical environment.

  1. Gamma heating in LMFBR media

    International Nuclear Information System (INIS)

    State-of-the-art approaches for the calculation of gamma heating in LMFBR core, blanket and reflector regions have been evaluated, with particular emphasis on coupled neutron-gamma methods/cross section sets. The major source of calculational error was found to be the apparent failure to impose a mass-energy balance on total gamma energy yield from neutron capture and other interactions in the preparation of representative neutron-gamma cross section sets. The applicability of many simplifying assumptions was demonstrated, including: volume-weighted homogenization, insensitivity to the shape of the gamma-source-spectrum, gamma energy deposition equal to gamma energy source more than 10 cm inside large zones of uniform composition, and the negligible effect of bremsstrahlung. A simple one-group method was developed to permit rapid, accurate estimation of the large (factor of 2) changes in the gamma energy deposition-to-source ratio possible near region interfaces. The approach, which also ensures conservation of mass-energy, was used in conjunction with coupled neutron-gamma computations to verify that previous experimental measurements of gamma heating in an LMFBR blanket mockup at M. I. T. were in accord with theoretical expectations within the experimental precision of +-10%

  2. Gamma heating in LMFBR media

    Energy Technology Data Exchange (ETDEWEB)

    Kalra, M.S.; Drisoll, M.J.

    1976-02-01

    State-of-the-art approaches for the calculation of gamma heating in LMFBR core, blanket and reflector regions have been evaluated, with particular emphasis on coupled neutron-gamma methods/cross section sets. The major source of calculational error was found to be the apparent failure to impose a mass-energy balance on total gamma energy yield from neutron capture and other interactions in the preparation of representative neutron-gamma cross section sets. The applicability of many simplifying assumptions was demonstrated, including: volume-weighted homogenization, insensitivity to the shape of the gamma-source-spectrum, gamma energy deposition equal to gamma energy source more than 10 cm inside large zones of uniform composition, and the negligible effect of bremsstrahlung. A simple one-group method was developed to permit rapid, accurate estimation of the large (factor of 2) changes in the gamma energy deposition-to-source ratio possible near region interfaces. The approach, which also ensures conservation of mass-energy, was used in conjunction with coupled neutron-gamma computations to verify that previous experimental measurements of gamma heating in an LMFBR blanket mockup at M. I. T. were in accord with theoretical expectations within the experimental precision of +-10%.

  3. The GAMMA-400 Space Mission

    CERN Document Server

    Cumani, P; Bonvicini, V; Topchiev, N P; Adriani, O; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Bergstrom, L; Berti, E; Bigongiari, G; Bobkov, S G; Boezio, M; Bogomolov, E A; Bonechi, S; Bongi, M; Bottai, S; Castellini, G; Cattaneo, P W; Dedenko, G L; De Donato, C; Dogiel, V A; Gorbunov, M S; Gusakov, Yu V; Hnatyk, B I; Kadilin, V V; Kaplin, V A; Kaplun, A A; Kheymits, M D; Korepanov, V E; Larsson, J; Leonov, A A; Loginov, V A; Longo, F; Maestro, P; Marrocchesi, P S; Menshenin, A L; Mikhailov, V V; Mocchiutti, E; Moiseev, A A; Mori, N; Moskalenko, I V; Naumov, P Yu; Papini, P; Pearce, M; Picozza, P; Popov, A V; Rappoldi, A; Ricciarini, S; Runtso, M F; Ryde, F; Serdin, O V; Sparvoli, R; Spillantini, P; Suchkov, S I; Tavani, M; Taraskin, A A; Tiberio, A; Tyurin, E M; Ulanov, M V; Vacchi, A; Vannuccini, E; Vasilyev, G I; Yurkin, Yu T; Zampa, N; Zirakashvili, V N; Zverev, V G

    2015-01-01

    GAMMA-400 is a new space mission which will be installed on board the Russian space platform Navigator. It is scheduled to be launched at the beginning of the next decade. GAMMA-400 is designed to study simultaneously gamma rays (up to 3 TeV) and cosmic rays (electrons and positrons from 1 GeV to 20 TeV, nuclei up to 10$^{15}$-10$^{16}$ eV). Being a dual-purpose mission, GAMMA-400 will be able to address some of the most impelling science topics, such as search for signatures of dark matter, cosmic-rays origin and propagation, and the nature of transients. GAMMA-400 will try to solve the unanswered questions on these topics by high-precision measurements of the Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission and the spectra of cosmic-ray electrons + positrons and nuclei, thanks to excellent energy and angular resolutions.

  4. Cosmic gamma rays from quasars

    International Nuclear Information System (INIS)

    The diffuse gamma radiation consists of the galactic and extragalactic components. The latter component is of special interest on account of its cosmological significance. Following the method recently proposed to estimate the gamma ray flux from galaxy clusters, and the detection of gamma rays from the quasars 3C273, the data base of the SAS II satellite was used to estimate the contribution from quasars to the extragalactic gamma ray flux. It is shown that quasars as a whole are significant gamma ray contributors, the average gamma ray flux per quasar in the energy range 35 MeV to 100 Mev being (1.3 + or - 0.9) x .00001 cm(-2)s(-1)sr(-1)

  5. Cosmic gamma rays from quasars

    Science.gov (United States)

    Lau, M. M.; Young, E. C. M.

    1985-01-01

    The diffuse gamma radiation consists of the galactic and extragalactic components. The latter component is of special interest on account of its cosmological significance. Following the method recently proposed to estimate the gamma ray flux from galaxy clusters, and the detection of gamma rays from the quasars 3C273, the data base of the SAS II satellite was used to estimate the contribution from quasars to the extragalactic gamma ray flux. It is shown that quasars as a whole are significant gamma ray contributors, the average gamma ray flux per quasar in the energy range 35 MeV to 100 Mev being (1.3 + or - 0.9) x .00001 cm(-2)s(-1)sr(-1).

  6. Selective Natural Gamma Logging

    International Nuclear Information System (INIS)

    Natural gamma logging can be used for determining the bismuth-214 (or RaC) content of uranium-bearing rocks. As the equilibrium coefficient of ores cannot be satisfactorily measured in situ, the log obtained can not be used to determine uranium content directly. The principle of the new technique of selective natural gamma logging is the use of the photoelectric effect due to the presence of uranium in rock. Natural gamma radiations are emitted but then scattered by the ore. The presence of uranium causes a change in the shape of the scattered gamma spectrum and this change can be related to the uranium content. The authors show that, if one applies the similitude principle to the transport equation for gamma radiation, the numerical value of a certain parameter P, representing the ratio of the number of counts obtained in two bands I1 and I2 of the scattered gamma spectrum, depends on the value of the equivalent atomic number of the rock (Zeq). For any given deposit the value of the parameter varies mainly with the uranium content qu and very little with the chemical composition of the matrix. The first laboratory tests were carried out on concrete models of uranium ore. Examination of spectra obtained (using a 400-channel selector) showed that the two boundaries I1 and I2 should range between 100 and 150 keV and 300 and 700 keV respectively. Each value of the parameter P obtained in this manner is divided by the value Ps obtained from one of the models used as a reference. The experiment showed that the normalized parameter, i. e., Px =P/PS, was a function of the content, having the shape log Px = A + Bqu. The coefficients A and B are calibration standards whose precise determination requires measurements taken in as large a number as possible of models with known uranium content. In laboratory conditions the degree of error is between 10 and 20% for contents of about 0.5% A field survey rig mounted on a lorry has been developed. It comprises a Nal

  7. gamma. -hexachlorocyclohexane (. gamma. -HCH) activates washed rabbit platelets

    Energy Technology Data Exchange (ETDEWEB)

    Lalau-Keraly, C.; Delautier, D.; Benveniste, J.; Puiseux-Dao, S.

    1986-03-01

    In guinea-pig macrophages, ..gamma..-HCH triggers activation of the phosphatidylinositol cycle and Ca/sup 2 +/ mobilization. Since these two biochemical events are also involved in platelet activation, the authors examined the effects of ..gamma..-HCH on washed rabbit platelets. Release of /sup 14/C-serotonin (/sup 14/C-5HT) and ATP from platelets prelabelled with /sup 14/C-5HT was measured simultaneously with aggregation. ..gamma..-HCH induced shape-change, aggregation and release reaction of platelets. Maximal aggregation (89 arbitrary units, AU), was observed using 170 ..mu..M ..gamma..-HCH, and was associated with 38.1 +/- 6.9% and 161 +/- 48 nM for /sup 14/C-5HT and ATP release respectively (mean +/- 1 SD, n=3). Using 80 ..mu..M ..gamma..-HCH yielded 18 AU, 12.8 +/- 1.0% and 27 +/- 14 nM for aggregation, C-5HT and ATP release respectively (n=3). No effect was observed with 40 ..mu.. M ..gamma..-HCH. Aspirin (ASA), a cyclooxygenase blocker, did not affect ..gamma..-HCH-induced platelet activation. Apyrase (APY), an ADP scavenger, inhibited by 90% aggregation induced by 170 ..mu..M ..gamma..-HCH and slightly inhibited (15%) the /sup 14/C-5HT release. In the presence of both ASA and APY, 96% inhibition of aggregation and 48% inhibition of /sup 14/C-5HT release were observed. Thus, ..gamma..-HCH induced platelet activation in a dose-dependent manner ADP, but not cyclooxygenase-dependent arachidonate metabolites, is involved in ..gamma..-HCH-induced aggregation, whereas, both appear to play a role in ..gamma..-HCH-induced release reaction.

  8. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  9. Gamma irradiation devices

    International Nuclear Information System (INIS)

    The main parameters and the preparation procedures of the gamma radiation sources frequently applied for irradiation purposes are discussed. In addition to 60Co and 137Cs sources also the nuclear power plants offer further opportunities: spent fuel elements and products of certain (n,γ) reactions can serve as irradiation sources. Laboratory scale equipments, pilot plant facilities for batch or continuous operation, continuous industrial irradiators and special multipurpose, mobile and panorama type facilities are reviewed including those in Canada, USA, India, the Soviet Union, Hungary, UK, Japan and Australia. For irradiator design the source geometry dependence of the spatial distribution of dose rates can be calculated. (V.N.)

  10. Gamma-scintigraphy

    International Nuclear Information System (INIS)

    Gamma-scintigraphy is a medical technique making it possible to fix the image of certain organs after the concentration in these of emitting radioactive products. It is already widely used in the case of the thyroid gland with iodine-132 by applying the isotope iodine 131. The study of the liver and gall bladder is carried out using colloidal gold 198 and Bengal pink marked with iodine 131. Serum albumin marked with iodine 131 makes it possible to study rachidian blockages. Other applications can already be foreseen in this direction. (author)

  11. Decays $h\\to \\gamma \\gamma, \\, \\gamma Z$ in the Two Higgs Doublet Model Type III

    CERN Document Server

    Cordero-Cid, A; Honorato, C G; Moretti, S

    2015-01-01

    We study the enhancement of the branching ratios of the decays $h \\to \\gamma \\gamma, \\, \\gamma Z$ in the Two Higgs Doublet Model Type III, assuming a four-zero Yukawa Texture and a general Higgs potential. We show that these processes are very sensitive to the flavor pattern of the Yukawa texture and the structure of the triple coupling $h H^\\pm H^\\mp$ from the Higgs potential. We can accomodate the parameters of the model such that one can obtain the $h \\to\\gamma \\gamma$ rates reported by the LHC and at the same time we can get a $ h \\to \\gamma Z$ fraction larger than in the SM and within experimental reach. The possibility of obtaining a light charged Higgs boson within the ensuing parameter space and compatible with current experimental measurements is also presented.

  12. Advantages of exclusive \\gamma\\gamma production to probe high mass systems

    CERN Document Server

    Martin, A D

    2016-01-01

    We recall that the exclusive production of high mass objects via \\gamma\\gamma fusion at the LHC is not strongly suppressed in comparison with inclusive \\gamma\\gamma fusion. Therefore it may be promising to study new objects produced by the \\gamma\\gamma subprocess in experiments with exclusive kinematics. We list the main advantages of exclusive experiments.

  13. The neutron-gamma Feynman variance to mean approach: gamma detection and total neutron-gamma detection (theory and practice)

    OpenAIRE

    Chernikova, Dina; Axell, Kåre; Avdic, Senada; Pázsit, Imre; Nordlund, Anders

    2014-01-01

    Two versions of the neutron-gamma variance to mean (Feynman-alpha method or Feynman-Y function) formula for either gamma detection only or total neutron-gamma detection, respectively, are derived and compared in this paper. The new formulas have a particular importance for detectors of either gamma photons or detectors sensitive to both neutron and gamma radiation. If applied to a plastic or liquid scintillation detector, the total neutron-gamma detection Feynman-Y expression corresponds to a...

  14. Gamma-Gamma Absorption in the Broad Line Region Radiation Fields of Gamma-Ray Blazars

    CERN Document Server

    Boettcher, Markus

    2016-01-01

    The expected level of gamma-gamma absorption in the Broad Line Region (BLR) radiation field of gamma-ray loud Flat Spectrum Radio Quasars (FSRQs)is evaluated as a function of the location of the gamma-ray emission region. This is done self-consistently with parameters inferred from the shape of the spectral energy distribution (SED) in a single-zone leptonic EC-BLR model scenario. We take into account all geometrical effects both in the calculation of the gamma-gamma opacity and the normalization of the BLR radiation energy density. As specific examples, we study the FSRQs 3C279 and PKS 1510-089, keeping the BLR radiation energy density at the location of the emission region fixed at the values inferred from the SED. We confirm previous findings that the optical depth due to $\\gamma\\gamma$ absorption in the BLR radiation field exceeds unity for both 3C279 and PKS 1510-089 for locations of the gamma-ray emission region inside the inner boundary of the BLR. It decreases monotonically, with distance from the cen...

  15. Generalized gamma frailty model.

    Science.gov (United States)

    Balakrishnan, N; Peng, Yingwei

    2006-08-30

    In this article, we present a frailty model using the generalized gamma distribution as the frailty distribution. It is a power generalization of the popular gamma frailty model. It also includes other frailty models such as the lognormal and Weibull frailty models as special cases. The flexibility of this frailty distribution makes it possible to detect a complex frailty distribution structure which may otherwise be missed. Due to the intractable integrals in the likelihood function and its derivatives, we propose to approximate the integrals either by Monte Carlo simulation or by a quadrature method and then determine the maximum likelihood estimates of the parameters in the model. We explore the properties of the proposed frailty model and the computation method through a simulation study. The study shows that the proposed model can potentially reduce errors in the estimation, and that it provides a viable alternative for correlated data. The merits of proposed model are demonstrated in analysing the effects of sublingual nitroglycerin and oral isosorbide dinitrate on angina pectoris of coronary heart disease patients based on the data set in Danahy et al. (sustained hemodynamic and antianginal effect of high dose oral isosorbide dinitrate. Circulation 1977; 55:381-387). PMID:16220516

  16. Gamma-hadron families and scaling violation

    International Nuclear Information System (INIS)

    For three different interaction models we have simulated gamma-hadron families, including the detector (Pamir emulsion chamber) response. Rates of gamma families, hadrons, and hadron-gamma ratios were compared with experiments

  17. Cyclic oxidation behavior of beta+gamma overlay coatings on gamma and gamma+gamma-prime alloys

    Science.gov (United States)

    Nesbitt, J. A.; Pilsner, B. H.; Carol, L. A.; Heckel, R. W.

    1984-01-01

    Detailed experimental studies of the cyclic oxidation behavior of low-pressure plasma sprayed beta+gamma coasting on gamma-phase Ni-Cr-Al alloys have shown the correlation of weight change, oxide type, and Cr and Al concentration-distance profiles as a function of oxidation time. Of special interest was the transition to breakway oxidation due to the loss of the Al flux to the oxide and the failure of the coated alloy to form an Al2O3-rich oxide scale. The experimental results on beta+gamma/gamma coating systems were used as the basis of a numerical model (ternary, semi-infinite, finite-difference analysis) which accurately predicted changes in Cr and Al concentration-distance profiles. The model was used to study parameters critical to enhancing the life of coatings which fail by a combination of Al loss in forming the oxide scale and Al loss via interdiffusion with the substrate alloy. Comparisons of beta+gamma/gamma coating behavior are made to the oxidation of coated gamma+gamma-prime substrates, both ternary Ni-Cr-Al alloys and Mar-M 247-type alloys.

  18. Airborne gamma-ray spectrometry

    DEFF Research Database (Denmark)

    Hovgaard, Jens

    A new method - Noise Adjusted Singular Value Decomposition, NASVD - for processing gamma-ray spectra has been developed as part of a Ph.D. project. By using this technique one is able to decompose a large set of data - for example from airborne gamma-ray surveys - into a few spectral components. ...

  19. Kerma constant of gamma radiation

    International Nuclear Information System (INIS)

    The values are tabulated of the gamma kerma constant for 106 radionuclides and an energy threshold of δ=0, 10, 20 and 30 keV. The calculated values will be useful in gamma radiation protection for ease of calculation of the kerma rate from a point radiation source. The study was required in view of the consistent introduction of SI units. (author)

  20. Gamma camera with reflectivity mask

    International Nuclear Information System (INIS)

    A gamma camera is described with a plurality of photodetectors arranged for locating flashes of light produced by a scintillator in response to incident radiation. Masking material is arranged in a radially symmetric pattern on the front face of the scintillator about the axis of each photodetector to reduce the amount of internal reflection of optical photons induced by gamma ray photons

  1. AGATA - Advanced Gamma Tracking Array

    CERN Document Server

    Akkoyun, S; Alikhani, B; Ameil, F; de Angelis, G; Arnold, L; Astier, A; Ataç, A; Aubert, Y; Aufranc, C; Austin, A; Aydin, S; Azaiez, F; Badoer, S; Balabanski, D L; Barrientos, D; Baulieu, G; Baumann, R; Bazzacco, D; Beck, F A; Beck, T; Bednarczyk, P; Bellato, M; Bentley, M A; Benzoni, G; Berthier, R; Berti, L; Beunard, R; Bianco, G Lo; Birkenbach, B; Bizzeti, P G; Bizzeti-Sona, A M; Blanc, F Le; Blasco, J M; Blasi, N; Bloor, D; Boiano, C; Borsato, M; Bortolato, D; Boston, A J; Boston, H C; Bourgault, P; Boutachkov, P; Bouty, A; Bracco, A; Brambilla, S; Brawn, I P; Brondi, A; Broussard, S; Bruyneel, B; Bucurescu, D; Burrows, I; Bürger, A; Cabaret, S; Cahan, B; Calore, E; Camera, F; Capsoni, A; Carrió, F; Casati, G; Castoldi, M; Cederwall, B; Cercus, J -L; Chambert, V; Chambit, M El; Chapman, R; Charles, L; Chavas, J; Clément, E; Cocconi, P; Coelli, S; Coleman-Smith, P J; Colombo, A; Colosimo, S; Commeaux, C; Conventi, D; Cooper, R J; Corsi, A; Cortesi, A; Costa, L; Crespi, F C L; Cresswell, J R; Cullen, D M; Curien, D; Czermak, A; Delbourg, D; Depalo, R; Descombes, T; Désesquelles, P; Detistov, P; Diarra, C; Didierjean, F; Dimmock, M R; Doan, Q T; Domingo-Pardo, C; Doncel, M; Dorangeville, F; Dosme, N; Drouen, Y; Duchêne, G; Dulny, B; Eberth, J; Edelbruck, P; Egea, J; Engert, T; Erduran, M N; Ertürk, S; Fanin, C; Fantinel, S; Farnea, E; Faul, T; Filliger, M; Filmer, F; Finck, Ch; de France, G; Gadea, A; Gast, W; Geraci, A; Gerl, J; Gernhäuser, R; Giannatiempo, A; Giaz, A; Gibelin, L; Givechev, A; Goel, N; González, V; Gottardo, A; Grave, X; Grȩbosz, J; Griffiths, R; Grint, A N; Gros, P; Guevara, L; Gulmini, M; Görgen, A; Ha, H T M; Habermann, T; Harkness, L J; Harroch, H; Hauschild, K; He, C; Hernández-Prieto, A; Hervieu, B; Hess, H; Hüyük, T; Ince, E; Isocrate, R; Jaworski, G; Johnson, A; Jolie, J; Jones, P; Jonson, B; Joshi, P; Judson, D S; Jungclaus, A; Kaci, M; Karkour, N; Karolak, M; Kaşkaş, A; Kebbiri, M; Kempley, R S; Khaplanov, A; Klupp, S; Kogimtzis, M; Kojouharov, I; Korichi, A; Korten, W; Kröll, Th; Krücken, R; Kurz, N; Ky, B Y; Labiche, M; Lafay, X; Lavergne, L; Lazarus, I H; Leboutelier, S; Lefebvre, F; Legay, E; Legeard, L; Lelli, F; Lenzi, S M; Leoni, S; Lermitage, A; Lersch, D; Leske, J; Letts, S C; Lhenoret, S; Lieder, R M; Linget, D; Ljungvall, J; Lopez-Martens, A; Lotodé, A; Lunardi, S; Maj, A; van der Marel, J; Mariette, Y; Marginean, N; Marginean, R; Maron, G; Mather, A R; Mȩczyński, W; Mendéz, V; Medina, P; Melon, B; Menegazzo, R; Mengoni, D; Merchan, E; Mihailescu, L; Michelagnoli, C; Mierzejewski, J; Milechina, L; Million, B; Mitev, K; Molini, P; Montanari, D; Moon, S; Morbiducci, F; Moro, R; Morrall, P S; Möller, O; Nannini, A; Napoli, D R; Nelson, L; Nespolo, M; Ngo, V L; Nicoletto, M; Nicolini, R; Noa, Y Le; Nolan, P J; Norman, M; Nyberg, J; Obertelli, A; Olariu, A; Orlandi, R; Oxley, D C; Özben, C; Ozille, M; Oziol, C; Pachoud, E; Palacz, M; Palin, J; Pancin, J; Parisel, C; Pariset, P; Pascovici, G; Peghin, R; Pellegri, L; Perego, A; Perrier, S; Petcu, M; Petkov, P; Petrache, C; Pierre, E; Pietralla, N; Pietri, S; Pignanelli, M; Piqueras, I; Podolyak, Z; Pouhalec, P Le; Pouthas, J; Pugnére, D; Pucknell, V F E; Pullia, A; Quintana, B; Raine, R; Rainovski, G; Ramina, L; Rampazzo, G; La Rana, G; Rebeschini, M; Recchia, F; Redon, N; Reese, M; Reiter, P; Regan, P H; Riboldi, S; Richer, M; Rigato, M; Rigby, S; Ripamonti, G; Robinson, A P; Robin, J; Roccaz, J; Ropert, J -A; Rossé, B; Alvarez, C Rossi; Rosso, D; Rubio, B; Rudolph, D; Saillant, F; Şahin, E; Salomon, F; Salsac, M -D; Salt, J; Salvato, G; Sampson, J; Sanchis, E; Santos, C; Schaffner, H; Schlarb, M; Scraggs, D P; Seddon, D; Şenyiğit, M; Sigward, M -H; Simpson, G; Simpson, J; Slee, M; Smith, J F; Sona, P; Sowicki, B; Spolaore, P; Stahl, C; Stanios, T; Stefanova, E; Stézowski, O; Strachan, J; Suliman, G; Söderström, P -A; Tain, J L; Tanguy, S; Tashenov, S; Theisen, Ch; Thornhill, J; Tomasi, F; Toniolo, N; Touzery, R; Travers, B; Triossi, A; Tripon, M; Tun-Lanoë, K M M; Turcato, M; Unsworth, C; Ur, C A; Valiente-Dobon, J J; Vandone, V; Vardaci, E; Venturelli, R; Veronese, F; Veyssiere, Ch; Viscione, E; Wadsworth, R; Walker, P M; Warr, N; Weber, C; Weisshaar, D; Wells, D; Wieland, O; Wiens, A; Wittwer, G; Wollersheim, H J; Zocca, F; Zamfir, N V; Ziȩbliński, M; Zucchiatti, A

    2011-01-01

    The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation gamma-ray spectrometer. AGATA is based on the technique of gamma-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a gamma ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realization of gamma-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly-segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterization of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorith...

  2. Sterilization by gamma irradiation

    International Nuclear Information System (INIS)

    Since 1980 the National Institute of Nuclear Research counts with an Industrial Gamma Irradiator, for the sterilization of raw materials and finished products. Through several means has been promoted the use of this technology as alternative to conventional methods of sterilization as well as steam treatment and ethylene oxide. As a result of the made promotion this irradiator has come to its saturation limit being the sterilization irradiation one of the main services that National Institute of Nuclear Research offers to producer enterprises of disposable materials of medical use also of raw materials for the elaboration of cosmetic products and pharmaceuticals as well as dehydrated foods. It is presented the trend to the sterilization service by irradiation showed by the compilation data in a survey made by potential customers. (Author)

  3. Gamma spectroscopy vials standardization

    International Nuclear Information System (INIS)

    Three types of plastic vials were defined by GTR 5 (Radioprotection Instrumentation Committee) according to the needs of laboratories of measuring by gamma spectrometry. A transparent (SG 50 T) or opaque (SG 50 N) vial of 50 cm3 for the range of activities more than 2,5.10-3 Bq/cm3. A transparent (SG 500 T) or opaque (SG 500 N) vial of 500 cm3 for low activities (at least 5.10-4 Bq/cm3), but with the possibility of using theses samples in existing automatic runs. A transparent (SG 3000 T) vial of 3000 cm3 allowing to obtain the minimum level of activity (at least 10-4 Bq/cm3), owing to the shape which envelopes the detector. The LMRI can supply straight standards in SG 50 N and SG 500 N vials. The moulds of these vials are the property of the CEA which insures the continuity of production

  4. Planetary gamma-ray spectroscopy

    International Nuclear Information System (INIS)

    The chemical composition of a planet can be inferred from the gamma rays escaping from its surface and can be used to study its origin and evolution. The measured intensities of certain gamma rays of specific energies can be used to determine the abundances of a number of elements. The major sources of these gamma-ray lines are the decay of natural radionuclides, reactions induced by energetic galactic-cosmic-ray particles, capture of low energy neutrons, and solar-proton-induced radioactivities. The fluxes of the more intense gamma-ray lines emitted from 30 elements were calculated using current nuclear data and existing models. The source strengths for neutron-capture reactions were modified from those previously used. The fluxes emitted from a surface of average lunar composition are reported for 288 gamma-ray lines. These theoretical fluxes have been used elsewhere to convert the data from the Apollo gamma-ray spectrometers to elemental abundances and can be used with results from future missions to map the concentrations of a number of elements over a planet's surface. Detection sensitivities for these elements are examined and applications of gamma-ray spectroscopy for future orbiters to Mars and other solar-system objects are discussed

  5. Planetary gamma-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Reedy, R.C.

    1978-01-01

    The chemical composition of a planet can be inferred from the gamma rays escaping from its surface and can be used to study its origin and evolution. The measured intensities of certain gamma rays of specific energies can be used to determine the abundances of a number of elements. The major sources of these gamma-ray lines are the decay of natural radionuclides, reactions induced by energetic galactic-cosmic-ray particles, capture of low energy neutrons, and solar-proton-induced radioactivities. The fluxes of the more intense gamma-ray lines emitted from 30 elements were calculated using current nuclear data and existing models. The source strengths for neutron-capture reactions were modified from those previously used. The fluxes emitted from a surface of average lunar composition are reported for 288 gamma-ray lines. These theoretical fluxes have been used elsewhere to convert the data from the Apollo gamma-ray spectrometers to elemental abundances and can be used with results from future missions to map the concentrations of a number of elements over a planet's surface. Detection sensitivities for these elements are examined and applications of gamma-ray spectroscopy for future orbiters to Mars and other solar-system objects are discussed.

  6. Economics of gamma irradiation processing

    International Nuclear Information System (INIS)

    The gamma-ray irradiation business started at the Takasaki Laboratory of Japan Atomic Energy Research Institute. The irradiation facilities were constructed thereafter at various sites. The facilities must accept various types of irradiation, and must be constructed as multi-purpose facilities. The cost of irradiation consists of the cost of gamma sources, construction expense, personnel expense, management expense, and bank interest. Most of the expenses are considered to be fixed expense, and the amount of irradiation treatment decides the original costs of work. The relation between the irradiation dose and the construction expense shows the larger facility is more economical. The increase of amount of treatment reduces the original cost. The utilization efficiency becomes important when the amount of treatment and the source intensity exceed some values. The principal subjects of gamma-ray irradiation business are the sterilization of medical tools and foods for aseptic animals, the improvement of quality of plastic goods, and the irradiation of foods. Among them, the most important subject is the sterilization of medical tools. The cost of gamma irradiation per m3 in still more expensive than that by ethylene oxide gas sterilization. However, the demand of gamma-ray irradiation is increasing. For the improvement of quality of plastic goods, electron irradiation is more favourable than the gamma irradiation. In near future, the economical balance of gamma irradiation can be achieved. (Kato, T.)

  7. $\\gamma\\gamma$ physics with the KLOE experiment

    CERN Document Server

    Archilli, F; Badoni, D; Balwierz, I; Bencivenni, G; Bini, C; Bloise, C; Bocci, V; Bossi, F; Branchini, P; Budano, A; Bulychjev, S A; Campana, P; Capon, G; Ceradini, F; Ciambrone, P; Czerwinski, E; Dane, E; De Lucia, E; De Robertis, G; De Santis, A; De Zorzi, G; Di Domenico, A; Di Donato, C; Domenici, D; Erriquez, O; Fanizzi, G; Felici, G; Fiore, S; Franzini, P; Gauzzi, P; Giovannella, S; Gonnella, F; Graziani, E; Happacher, F; Hoistad, B; Iarocci, E; Jacewicz, M; Johansson, T; Kulikov, V; Kupsc, A; Lee-Franzini, J; Loddo, F; Martemianov, M; Martini, M; Matsyuk, M; Messi, R; Miscetti, S; Morello, G; Moricciani, D; Moskal, P; Nguyen, F; Passeri, A; Patera, V; Longhi, I Prado; Ranieri, A; Santangelo, P; Sarra, I; Schioppa, M; Sciascia, B; Sciubba, A; Silarski, M; Taccini, C; Tortora, L; Venanzoni, G; Versaci, R; Wislicki, W; Wolke, M; Zdebik, J

    2011-01-01

    The processes $e^+e^-\\to e^+e^-X$, with $X$ being either the $\\eta$ meson or $\\pi^0\\pi^0$, are studied at DA$\\Phi$NE, with $e^+e^-$ beams colliding at $\\sqrt{s}\\simeq1$ GeV, below the $\\phi$ resonance peak. The data sample is from an integrated luminosity of 240 pb$^{-1}$, collected by the KLOE experiment without tagging of the outgoing $e^+e^-$. Preliminary results are presented on the observation of the $\\gamma\\gamma\\to\\eta$ process, with both $\\eta\\to\\pi^+\\pi^-\\pi^0$ and $\\eta\\to\\pi^0\\pi^0\\pi^0$ channels, and the evidence for $\\gamma\\gamma\\to\\pi^0\\pi^0$ production at low $\\pi^0\\pi^0$ invariant mass.

  8. Total Cross Section in $\\gamma\\gamma$ Collisions at LEP

    CERN Document Server

    Acciarri, M; Adriani, O; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, L; Balandras, A; Baldew, S V; Todorova-Nová, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Cucciarelli, S; Dai, T S; van Dalen, J A; D'Alessandro, R; De Asmundis, R; Déglon, P L; Degré, A; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Van Dierendonck, D N; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Dufournaud, D; Duinker, P; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ewers, A; Extermann, Pierre; Fabre, M; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Hofer, H; Holzner, G; Hoorani, H; Hou, S R; Hu, Y; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Khan, R A; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Kopp, A; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Le Goff, J M; Leiste, R; Levchenko, P M; Li Chuan; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Lugnier, L; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Marian, G; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Moulik, T; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Ofierzynski, R A; Organtini, G; Oulianov, A; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Paramatti, R; Park, H K; Park, I H; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Prokofiev, D O; Prokofev, D; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Rodin, J; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Roux, B; Rubio, Juan Antonio; Ruggiero, G; Rykaczewski, H; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Seganti, A; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S V; Suter, H; Swain, J D; Szillási, Z; Sztaricskai, T; Tang, X W; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, M; Wang, X L; Wang, Z M; Weber, A; Weber, M; Wienemann, P; Wilkens, H; Wu, S X; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhu, G Y; Zhu, R Y; Zichichi, A; Zilizi, G; Zimmermann, B; Zöller, M

    2001-01-01

    The reaction e+e- -> e+e- gamma* gamma* -> e+e- hadrons for quasi-real photons is studied using data from root(s) = 183 GeV up to 202 GeV. Results on the total cross sections sigma(e+e- -> e+e- hadrons) and sigma(+e- gamma* gamma* -> e+e- hadrons) are given for the two-photon centre-of-mass energies 5 GeV < Wgammagamma < 185 GeV. The total cross section of two real photons is described by a Regge parametrisation. We observe a steeper rise with the two-photon centre-of-mass energy as compared to the hadron-hadron and the photon-proton cross sections. The data are also compared to the expectations of different theoretical models.

  9. Gamma-ray Pulsar Revolution

    OpenAIRE

    Caraveo, Patrizia A.

    2013-01-01

    Isolated Neutron Stars (INSs) were the first sources identified in the field of high-energy gamma-ray astronomy. At first, in the 70s, there were only two identified sources, the Crab and Vela pulsars. However, although few in number, these objects were crucial in establishing the very concept of a gamma-ray source. Moreover, they opened up significant discovery space both in the theoretical and phenomenological fronts. The need to explain the copious gamma-ray emission of these pulsars led t...

  10. Bonds futures: Delta? No gamma!

    OpenAIRE

    Henrard, Marc

    2006-01-01

    Bond futures are liquid but complex instruments. Here they are analysed in a one-factor Gaussian HJM model. The in-the-model delta and out-of-the-model delta and gamma are studied. An explicit formula is provided for in-the-model delta. The out-of-the-model delta and gamma are equivalent to partial derivatives with respect to discount factors. In particular cases the derivative can not be obtained by standard techniques. The same situations lead to cases where the gammas (second order partial...

  11. Diamond gamma dose rate monitor; Debitmetre gamma en diamant

    Energy Technology Data Exchange (ETDEWEB)

    Brambilla, A.; Chambaud, P.; Tromson, D.; Bergonzo, P.; Foulon, F.; Joffre, F. [CEA Saclay, Dept. d' Electronique et d' Instrumentation Nucleaire, LETI, 91 - Gif-sur-Yvette (France)

    1999-07-01

    CVD (chemical vapor deposition) diamond detectors for X and gamma dose rate monitoring have been fabricated and tested in the 1 mGy/h to 1 kGy/h range. They show excellent performances in terms of sensitivity and linearity. Radiation hardness measurement under 60-Co gamma rays have demonstrated long term stability for integrated doses up to 500 kGy. (authors)

  12. Gamma-gamma angular correlation studies in 97Tc

    International Nuclear Information System (INIS)

    By use of multichannel goniometer gamma-gamma angular correlations have been measured in 97Tc. These data are used to deduce the E2/M1 mixing-ratios of several transitions. The spin of the 785.0 keV level is found to be 5/2. The reduced transition strengths as well as relative transition strengths are calculated for some transitions and are compared with the predictions of a recent theoretical calculation. (orig.)

  13. A preliminary analysis of {eta}({eta}{sup '}){yields}{pi}{sub 0{gamma}{gamma}} and {eta}{sup '{yields}{eta}{gamma}{gamma}} decays

    Energy Technology Data Exchange (ETDEWEB)

    Jora, Renata, E-mail: rjora@ifae.e [Grup de Fisica Teorica and IFAE, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain)

    2010-10-15

    We present preliminary results for the decay widths and the invariant mass spectra of the electromagnetic rare decays {eta}({eta}{sup '}){yields}{pi}{sub 0{gamma}{gamma}} and {eta}{sup '{yields}{eta}{gamma}{gamma}}.

  14. Gamma rays at airplane altitudes

    International Nuclear Information System (INIS)

    An examination of the gamma ray flux above 1 TeV in the atmosphere is needed to better understand the anomalous showers from point sources. Suggestions are made for future experiments on board airplanes

  15. Gamma probe dry bulk densities

    International Nuclear Information System (INIS)

    The gamma density probe is a useful instrument for measuring water content in small volumes of soil. Essentially, the gamma probe measures the density of the soil and water between a source and a detector. To transpose the gamma densities into water content, the dry bulk density of the soil is needed. A nondestructive method for estimating dry bulk densities for use with the gamma probe is proposed. The procedure is based on the assumption that water content values in a field dry condition were more stable than the dry bulk density values and could be transferred from one point to another. The procedure was successfully used on three areas in Reynolds Creek Experimental Watershed in southwest Idaho. (U.S.)

  16. Study of the $e^+ e^- \\to Z\\gamma\\gamma \\to q\\overline{q}\\gamma\\gamma$ Process at LEP

    CERN Document Server

    Acciarri, M; Adriani, O; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, L; Balandras, A; Baldew, S V; Todorova-Nová, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Cucciarelli, S; Dai, T S; van Dalen, J A; D'Alessandro, R; De Asmundis, R; Déglon, P L; Degré, A; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Van Dierendonck, D N; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Dufournaud, D; Duinker, P; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ewers, A; Extermann, Pierre; Fabre, M; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Hofer, H; Holzner, G; Hoorani, H; Hou, S R; Hu, Y; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Khan, R A; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Kopp, A; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Le Goff, J M; Leiste, R; Levchenko, P M; Li Chuan; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Lugnier, L; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Marian, G; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Moulik, T; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Ofierzynski, R A; Organtini, G; Oulianov, A; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Paramatti, R; Park, H K; Park, I H; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Prokofiev, D O; Prokofev, D; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Rodin, J; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Roux, B; Rubio, Juan Antonio; Ruggiero, G; Rykaczewski, H; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Seganti, A; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S V; Suter, H; Swain, J D; Szillási, Z; Sztaricskai, T; Tang, X W; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, M; Wang, X L; Wang, Z M; Weber, A; Weber, M; Wienemann, P; Wilkens, H; Wu, S X; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhu, G Y; Zhu, R Y; Zichichi, A; Zilizi, G; Zimmermann, B; Zöller, M

    2001-01-01

    The process e^+e^- -> Z gamma gamma -> q q~ gamma gamma$ is studied in 0.5\\,fb-1$ of data collected with the L3 detector at centre-of-mass energies between 130.1 GeV and 201.7 GeV. Cross sections are measured and found to be consistent with the Standard Model expectations. The study of the least energetic photon constrains the quartic gauge boson couplings to -0.008 GeV-2 < a_0/\\Lambda^2 < 0.005 GeV-2 and -0.007 GeV-2 < a_c/\\Lambda^2 < 0.011 GeV-2, at 95% confidence level.

  17. Gamma camera system

    International Nuclear Information System (INIS)

    The invention provides a composite solid state detector for use in deriving a display, by spatial coordinate information, of the distribution or radiation emanating from a source within a region of interest, comprising several solid state detector components, each having a given surface arranged for exposure to impinging radiation and exhibiting discrete interactions therewith at given spatially definable locations. The surface of each component and the surface disposed opposite and substantially parallel thereto are associated with impedence means configured to provide for each opposed surface outputs for signals relating the given location of the interactions with one spatial coordinate parameter of one select directional sense. The detector components are arranged to provide groupings of adjacently disposed surfaces mutually linearly oriented to exhibit a common directional sense of the spatial coordinate parameter. Means interconnect at least two of the outputs associated with each of the surfaces within a given grouping for collecting the signals deriving therefrom. The invention also provides a camera system for imaging the distribution of a source of gamma radiation situated within a region of interest

  18. Diamond gamma dose rate monitor

    International Nuclear Information System (INIS)

    CVD (chemical vapor deposition) diamond detectors for X and gamma dose rate monitoring have been fabricated and tested in the 1 mGy/h to 1 kGy/h range. They show excellent performances in terms of sensitivity and linearity. Radiation hardness measurement under 60-Co gamma rays have demonstrated long term stability for integrated doses up to 500 kGy. (authors)

  19. Magnetic angle for gamma rays

    International Nuclear Information System (INIS)

    In December 2002 astronomers at the University of California in Berkeley got a lucky break. A bright gamma-ray burst appeared in the sky within 18 degrees of the Sun, which was close enough to be picked up by the RHESSI solar satellite. Analysing data from the satellite, Wayne Coburn and Steven Boggs made the stunning discovery that the gamma rays from the burst - named GRB021206 - were linearly polarized. And not just by any amount, but by 80% - the maximum polarization theoretically possible. The discovery represents a major breakthrough in gamma-ray astronomy (Nature 423 415).Gamma-ray bursts are the most energetic events in the universe, typically corresponding to the conversion of 1% of the mass of the Sun into energy. Every day an average of about one of these brief flashes of gamma rays - which come from any direction in the sky and last a few tens of seconds - are detected. Observations of the optical afterglow of the bursts reveal that they originate in galaxies that are several billions of light-years away. But what causes the bursts, and how the gamma rays are actually produced, have, until recently, remained a mystery. It has been suggested that gamma-ray bursts result from supernovae - the explosions of massive stars that have used up all their fuel - and that the bursts might be the 'birth cries' of black holes. Some of this evidence is circumstantial. It is known, for example, that the host galaxies of the bursts are regions where massive stars are copiously forming. However, observations of the afterglow of GRB980425 in 1998 revealed a spectral signature that would be expected for a supernova. This provided the first compelling, but inconclusive, direct evidence for the link between gamma-ray bursts and supernovae. In March this year, however, this link was dramatically confirmed. The HETE-2 satellite detected a spectacular gamma-ray burst that was among the closest and brightest ever observed. GRB030329 was just two billion light-years away, which

  20. AcAP5蛋白N端片段的表达、纯化与活性评价%Expression, purification and evaluation of N-terminal domain of AcAP5 with Factor Xa inhibitory activity

    Institute of Scientific and Technical Information of China (English)

    刘爱华; 朱元军; 刘晓岩; 王银叶

    2013-01-01

    Ancylostoma anticoagulant peptide 5 (AcAP5) is a strong inhibitor of human coagulation factor Xa (FXa).The N-terminal residues (N40) of AcAP5 contains a domain that could combine with FXa.In order to determine whether N40 protein has FXa inhibitory effect,we cloned,expressed and purified the protein for activity evaluation.The DNA fragment coding N40 was amplified by PCR,cloned into pET-30a to construct recombinant plasmid pET30a-N40,and subsequently transformed into E.coli.BL21 (DE3).Expression of N40 was induced by isopropyl β-D-l-thiogalactopyranoside (IPTG),and the interest protein was identified by SDS-PAGE and purified using one-step nickel (Ni) affinity chromatography.Under the optimal expression condition (0.05 mM IPTG for 6 h at 37 ℃),the purity of N40 reached 90%.We also evaluated the inhibition activity of N40 protein on FXa,finding the IC50 was 4.58× 10 5 mol/L.This study suggests the N40 of AcAP5 could combine with FXa to inhibit FXa activity.%犬钩虫抗凝肽5 (Ancylostoma anticoagulant peptide 5,AcAP5)N端40个氨基酸片段(N40)含有与FXa结合的结构域.为研究N40的FXa抑制作用,我们克隆、表达和纯化了N40,并检测其生物活性.用PCR扩增N40基因;将PCR产物克隆至原核表达载体pET-30a中,构建质粒pET30a-N40;将其转化入大肠杆菌E.coli.BL21 (DE3)中,IPTG诱导目的蛋白表达,SDS-PAGE电泳鉴定,经过镍柱亲和层析纯化,用BCA法进行蛋白定量,测定该蛋白抑制FXa的活性.限制性酶切鉴定和基因测序结果显示重组质粒构建成功;SDS-PAGE结果显示目的蛋白在E.coli.BL21(DE3)中为可溶性表达,亲和层析纯化后获得了纯度约90%的蛋白,经活性鉴定该蛋白确有抑制FXa的活性.

  1. Higgs Self-Coupling in gamma-gamma Collisions

    CERN Document Server

    Belusevic, R

    2004-01-01

    To establish the Higgs mechanism experimentally, one has to determine the Higgs self-interaction potential responsible for the electroweak symmetry breaking. This requires a measurement of the trilinear and quadrilinear self-couplings of the Higgs particle, as predicted by the Standard Model (SM). We propose to measure the trilinear Higgs self-coupling in gamma-gamma collisions just above the kinematic threshold E_thr = 2M_H, where M_H is the Higgs mass. Our calculation reveals that the sensitivity of the cross-section sigma(gamma gamma -> HH) to the Higgs self-coupling is maximal near the 2M_H threshold for M_H = 115-150 GeV, and is larger than the sensitivities of sigma(e+e- -> ZHH) and sigma(e+e- -> nu nu HH) to this coupling for 2E_e H by constructing an X-band e-e- linac and a terawatt laser system in order to produce Compton-scattered gamma-ray beams for a 160-GeV photon collider (2E_e = 200 GeV); (b) add a positron source and repeat all measurements done at LEP and SLC with much better precision; and ...

  2. The top threshold effect in the $\\gamma\\gamma$ production at the LHC

    CERN Document Server

    Jain, Pankaj; Sanyal, Prasenjit; Verma, Ravindra K

    2016-01-01

    We compute the top quark threshold contributions to the $\\gamma\\gamma$ production at the LHC. These contributions become significant when the invariant mass of the photon pair, $M_{\\gamma\\gamma}$ just exceeds two times the mass of the top quark and induce some features in the $M_{\\gamma\\gamma}$ distribution, a hint of which is already visible in the recent data. We determine the magnitude of this threshold effect and investigate kinematic cuts which may enhance its significance.

  3. GammaModeler 3-D gamma-ray imaging technology

    International Nuclear Information System (INIS)

    The 3-D GammaModelertrademark system was used to survey a portion of the facility and provide 3-D visual and radiation representation of contaminated equipment located within the facility. The 3-D GammaModelertrademark system software was used to deconvolve extended sources into a series of point sources, locate the positions of these sources in space and calculate the 30 cm. dose rates for each of these sources. Localization of the sources in three dimensions provides information on source locations interior to the visual objects and provides a better estimate of the source intensities. The three dimensional representation of the objects can be made transparent in order to visualize sources located within the objects. Positional knowledge of all the sources can be used to calculate a map of the radiation in the canyon. The use of 3-D visual and gamma ray information supports improved planning decision-making, and aids in communications with regulators and stakeholders

  4. Quality assurance for gamma knives

    Energy Technology Data Exchange (ETDEWEB)

    Jones, E.D.; Banks, W.W.; Fischer, L.E. [Lawrence Livermore National Lab., CA (United States)

    1995-09-01

    This report describes and summarizes the results of a quality assurance (QA) study of the Gamma Knife, a nuclear medical device used for the gamma irradiation of intracranial lesions. Focus was on the physical aspects of QA and did not address issues that are essentially medical, such as patient selection or prescription of dose. A risk-based QA assessment approach was used. Sample programs for quality control and assurance are included. The use of the Gamma Knife was found to conform to existing standards and guidelines concerning radiation safety and quality control of external beam therapies (shielding, safety reviews, radiation surveys, interlock systems, exposure monitoring, good medical physics practices, etc.) and to be compliant with NRC teletherapy regulations. There are, however, current practices for the Gamma Knife not covered by existing, formalized regulations, standards, or guidelines. These practices have been adopted by Gamma Knife users and continue to be developed with further experience. Some of these have appeared in publications or presentations and are slowly finding their way into recommendations of professional organizations.

  5. Quality assurance for gamma knives

    International Nuclear Information System (INIS)

    This report describes and summarizes the results of a quality assurance (QA) study of the Gamma Knife, a nuclear medical device used for the gamma irradiation of intracranial lesions. Focus was on the physical aspects of QA and did not address issues that are essentially medical, such as patient selection or prescription of dose. A risk-based QA assessment approach was used. Sample programs for quality control and assurance are included. The use of the Gamma Knife was found to conform to existing standards and guidelines concerning radiation safety and quality control of external beam therapies (shielding, safety reviews, radiation surveys, interlock systems, exposure monitoring, good medical physics practices, etc.) and to be compliant with NRC teletherapy regulations. There are, however, current practices for the Gamma Knife not covered by existing, formalized regulations, standards, or guidelines. These practices have been adopted by Gamma Knife users and continue to be developed with further experience. Some of these have appeared in publications or presentations and are slowly finding their way into recommendations of professional organizations

  6. Mirror matter admixtures in K_S to gamma gamma

    CERN Document Server

    Sánchez-Colón, G; Sanchez-Colon, Gabriel; Garcia, Augusto

    2006-01-01

    The latest measurement of the K_S to gamma gamma branching ratio clearly shows an enhancement over the current theoretical prediction. As in other K and B meson decays, this invites to consider the possibility of the contribution of new physics. We study a particular form of the latter, which may be referred to as manifest mirror symmetry. The experimental data are described using previously determined values for the mixing angles of the admixtures of mirror matter in ordinary hadrons and by assuming that for pi^0, eta, eta', the mirror decay amplitudes have the same magnitudes as their ordinary counterparts.

  7. FEL system for gamma-gamma collider at TESLA

    International Nuclear Information System (INIS)

    The present paper contains the results of optimization of the free electron laser for the gamma-gamma collider at TESLA. A superconducting linear accelerator, similar to the TTF (TESLA Test Facility) accelerator, produces a driving electron beam for the FEL. The MOPA FEL scheme is studied when the radiation from a master oscillator is amplified in the FEL amplifier with tapered undulator. The FEL produces a radiation of TW level with a wavelength of 1 μm. Optimization of the FEL amplifier is performed with a three-dimensional, time-dependent simulation code FAST

  8. Free electron laser for gamma-gamma collider at TESLA

    International Nuclear Information System (INIS)

    The present paper contains the results of optimization of the free electron laser for the gamma-gamma collider at TESLA. A superconducting linear accelerator, similar to the TESLA test facility (TTF) accelerator, produces a driving electron beam for the FEL. The MOPA FEL scheme is studied when the radiation from a master oscillator is amplified in the FEL amplifier with tapered undulator. The FEL produces the radiation of TW level with a wavelength of 1 μm. Optimization of the FEL amplifier is performed with three-dimensional, time-dependent simulation code FAST

  9. Higgs Self-Coupling in gamma-gamma Collisions

    OpenAIRE

    Belusevic, R.; Jikia, G.

    2004-01-01

    To establish the Higgs mechanism experimentally, one has to determine the Higgs self-interaction potential responsible for the electroweak symmetry breaking. This requires a measurement of the trilinear and quadrilinear self-couplings of the Higgs particle, as predicted by the Standard Model (SM). We propose to measure the trilinear Higgs self-coupling in gamma-gamma collisions just above the kinematic threshold E_thr = 2M_H, where M_H is the Higgs mass. Our calculation reveals that the sensi...

  10. Single sneutrino production in $\\gamma\\gamma$ collisions

    CERN Document Server

    Chaichian, Masud; Roy, S; Yu, Z H

    2001-01-01

    We study the single production of sneutrinos with two leptons (or jets) via $\\gamma\\gamma$ collision in an R-parity ($R_{p}$) violating supersymmetric model. The subsequent decays of the sneutrino are also considered. The single production of sneutrinos may provide a significant test of supersymmetry and $R_p$-violation with flavour conserving and flavour changing final states. If such processes coming from $R_p$ violation are not detected, the parameter space of the model will be strongly constrained at the future Linear Collider.

  11. The neutron–gamma Feynman variance to mean approach: Gamma detection and total neutron–gamma detection (theory and practice)

    Energy Technology Data Exchange (ETDEWEB)

    Chernikova, Dina, E-mail: dina@nephy.chalmers.se [Chalmers University of Technology, Department of Applied Physics, Nuclear Engineering, Fysikgården 4, SE-412 96 Göteborg (Sweden); Axell, Kåre [Chalmers University of Technology, Department of Applied Physics, Nuclear Engineering, Fysikgården 4, SE-412 96 Göteborg (Sweden); Swedish Radiation Safety Authority, SE-171 16 Stockholm (Sweden); Avdic, Senada [University of Tuzla, Department of Physics, 75000 Tuzla, Bosnia and Herzegovina (Bosnia and Herzegovina); Pázsit, Imre; Nordlund, Anders [Chalmers University of Technology, Department of Applied Physics, Nuclear Engineering, Fysikgården 4, SE-412 96 Göteborg (Sweden); Allard, Stefan [Chalmers University of Technology, Department of Chemical and Biological Engineering, Nuclear Chemistry and Industrial Materials Recycling, Kemivagen 4, SE-412 96 Göteborg (Sweden)

    2015-05-11

    Two versions of the neutron–gamma variance to mean (Feynman-alpha method or Feynman-Y function) formula for either gamma detection only or total neutron–gamma detection, respectively, are derived and compared in this paper. The new formulas have particular importance for detectors of either gamma photons or detectors sensitive to both neutron and gamma radiation. If applied to a plastic or liquid scintillation detector, the total neutron–gamma detection Feynman-Y expression corresponds to a situation where no discrimination is made between neutrons and gamma particles. The gamma variance to mean formulas are useful when a detector of only gamma radiation is used or when working with a combined neutron–gamma detector at high count rates. The theoretical derivation is based on the Chapman–Kolmogorov equation with the inclusion of general reactions and corresponding intensities for neutrons and gammas, but with the inclusion of prompt reactions only. A one energy group approximation is considered. The comparison of the two different theories is made by using reaction intensities obtained in MCNPX simulations with a simplified geometry for two scintillation detectors and a {sup 252}Cf-source. In addition, the variance to mean ratios, neutron, gamma and total neutron–gamma are evaluated experimentally for a weak {sup 252}Cf neutron–gamma source, a {sup 137}Cs random gamma source and a {sup 22}Na correlated gamma source. Due to the focus being on the possibility of using neutron–gamma variance to mean theories for both reactor and safeguards applications, we limited the present study to the general analytical expressions for Feynman-alpha formulas.

  12. The neutron–gamma Feynman variance to mean approach: Gamma detection and total neutron–gamma detection (theory and practice)

    International Nuclear Information System (INIS)

    Two versions of the neutron–gamma variance to mean (Feynman-alpha method or Feynman-Y function) formula for either gamma detection only or total neutron–gamma detection, respectively, are derived and compared in this paper. The new formulas have particular importance for detectors of either gamma photons or detectors sensitive to both neutron and gamma radiation. If applied to a plastic or liquid scintillation detector, the total neutron–gamma detection Feynman-Y expression corresponds to a situation where no discrimination is made between neutrons and gamma particles. The gamma variance to mean formulas are useful when a detector of only gamma radiation is used or when working with a combined neutron–gamma detector at high count rates. The theoretical derivation is based on the Chapman–Kolmogorov equation with the inclusion of general reactions and corresponding intensities for neutrons and gammas, but with the inclusion of prompt reactions only. A one energy group approximation is considered. The comparison of the two different theories is made by using reaction intensities obtained in MCNPX simulations with a simplified geometry for two scintillation detectors and a 252Cf-source. In addition, the variance to mean ratios, neutron, gamma and total neutron–gamma are evaluated experimentally for a weak 252Cf neutron–gamma source, a 137Cs random gamma source and a 22Na correlated gamma source. Due to the focus being on the possibility of using neutron–gamma variance to mean theories for both reactor and safeguards applications, we limited the present study to the general analytical expressions for Feynman-alpha formulas

  13. Automatic gamma spectrometry analytical apparatus

    International Nuclear Information System (INIS)

    This invention falls within the area of quantitative or semi-quantitative analysis by gamma spectrometry and particularly refers to a device for bringing the samples into the counting position. The purpose of this invention is precisely to provide an automatic apparatus specifically adapted to the analysis of hard gamma radiations. To this effect, the invention relates to a gamma spectrometry analytical device comprising a lead containment, a detector of which the sensitive part is located inside the containment and additionally comprising a transfer system for bringing the analyzed samples in succession to a counting position inside the containment above the detector. A feed compartment enables the samples to be brought in turn one by one on to the transfer system through a duct connecting the compartment to the transfer system. Sequential systems for the coordinated forward feed of the samples in the compartment and the transfer system complete this device

  14. Gamma irradiators for radiation processing

    International Nuclear Information System (INIS)

    Radiation technology is one of the most important fields which the IAEA supports and promotes, and has several programmes that facilitate its use in the developing Member States. In view of this mandate, this Booklet on 'Gamma Irradiators for Radiation Processing' is prepared which describes variety of gamma irradiators that can be used for radiation processing applications. It is intended to present description of general principles of design and operation of the gamma irradiators available currently for industrial use. It aims at providing information to industrial end users to familiarise them with the technology, with the hope that the information contained here would assist them in selecting the most optimum irradiator for their needs. Correct selection affects not only the ease of operation but also yields higher efficiency, and thus improved economy. The Booklet is also intended for promoting radiation processing in general to governments and general public

  15. Scintillation counter, maximum gamma aspect

    International Nuclear Information System (INIS)

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  16. Gamma radiometric survey of Jamaica

    International Nuclear Information System (INIS)

    The results of a total gamma radiometric survey of Jamaica, carried out with car-borne instrumentation, are presented and the data compared with the contents of potassium, thorium and uranium in rocks and in surface (soil, stream-sediment, pan concentrate and water) samples obtained at six sites selected to be representative of the principal rock types and surface environments of Jamaica. The work formed part of an orientation study for a regional geochemical survey of the CARICOM countries of the Caribbean. The initial results indicate that enhanced gamma activity is correlated with enrichment in uranium and thorium, but not potassium, in terra rossa soils and/or bauxite deposits in limestone. Elsewhere, gamma levels are increased on the Above Rocks Cretaceous basement Inlier, where they correlate generally with the presence of volcanogenic sediments and a granodiorite intrusion. The lowest radioactivity was recorded in the vicinity of ultrabasic rocks in the Blue Mountains Inlier. (author)

  17. Beta-gamma discriminator circuit

    International Nuclear Information System (INIS)

    The major difficulty encountered in the determination of beta-ray dose in field conditions is generally the presence of a relatively high gamma-ray component. Conventional dosimetry instruments use a shield on the detector to estimate the gamma-ray component in comparison with the beta-ray component. More accurate dosimetry information can be obtained from the measured beta spectrum itself. At Los Alamos, a detector and discriminator circuit suitable for use in a portable spectrometer have been developed. This instrument will discriminate between gammas and betas in a mixed field. The portable package includes a 256-channel MCA which can be programmed to give a variety of outputs, including a spectral display, and may be programmed to read dose directly

  18. Design and Performance of the GAMMA-400 Gamma-Ray Telescope for Dark Matter Searches

    Science.gov (United States)

    Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu V.; Kaplin, V. A.; Kachanov, V. A.; Kheymits, M. D.; Leonov, A. A.; Longo, F.; Mazets, E. P.; Maestro, P.; Marrocchesi, P.; Mereminskiy, I. A.; Mikhailov, V. V.; Mocchiutti, E.; Moiseev, A. A.; Mori, N.; Moskalenko, I. V.; Naumov, P. Yu

    2012-01-01

    The GAMMA-400 gamma-ray telescope is designed to measure the fluxes of gamma-rays and cosmic-ray electrons (+) positrons, which can be produced by annihilation or decay of the dark matter particles, as well as to survey the celestial sphere in order to study point and extended sources of gamma-rays, measure energy spectra of Galactic and extragalactic diffuse gamma-ray emission, gamma-ray bursts, and gamma-ray emission from the Sun. GAMMA-400 covers the energy range from 100 MeV to 3000 GeV. Its angular resolution is approximately 0.01deg (E(sub gamma) greater than 100 GeV), the energy resolution approximately 1% (E(sub gamma) greater than 10 GeV), and the proton rejection factor approximately 10(exp 6). GAMMA-400 will be installed on the Russian space platform Navigator. The beginning of observations is planned for 2018.

  19. Dispersive treatment of $K_S\\to\\gamma\\gamma$ and $K_S\\to\\gamma\\ell^+\\ell^-$

    CERN Document Server

    Colangelo, Gilberto; Tunstall, Lewis C

    2016-01-01

    We analyse the rare kaon decays $K_S \\to \\gamma\\gamma$ and $K_S \\to \\gamma\\ell^+\\ell^-$ $(\\ell = e \\mbox{ or } \\mu)$ in a dispersive framework in which the weak Hamiltonian carries momentum. Our analysis extends predictions from lowest order $SU(3)_L\\times SU(3)_R$ chiral perturbation theory ($\\chi$PT$_3$) to fully account for effects from final-state interactions, and is free from ambiguities associated with extrapolating the kaon off-shell. Given input from $K_S \\to \\pi\\pi$ and $\\gamma\\gamma^{(*)}\\to\\pi\\pi$, we solve the once-subtracted dispersion relations numerically to predict the rates for $K_S \\to \\gamma\\gamma$ and $K_S \\to \\gamma\\ell^+\\ell^-$. In the leptonic modes, we find sizeable corrections to the $\\chi$PT$_3$ predictions for the integrated rates.

  20. Gamma radiation and plant breeding

    International Nuclear Information System (INIS)

    The Radiation Breeding Laboratory of the Agricultural Technic Institute, Ministry of Agriculture, Forestry and Fisheries has a gamma ray field, which ranks second in the world in capacity and scale, and other gamma ray irradiation facilities. In commemoration of its 20th anniversary, the booklet described the history up to its establishment and introduced various facilities and the achievements of the laboratory. It also reviewed improved varieties produced by irradiation upon request and introduced radiation-improved varieties in Japan and abroad, characteristics of these mutation-improved varieties and irradiation methods. (Chiba, N.)

  1. Radiosurgery by Leksell gamma knife

    International Nuclear Information System (INIS)

    The learning objectives of the lecture were as follows: to learn basic principles of Leksell gamma knife (LGK) radiosurgery; to discuss imaging, treatment planning and optimization procedures; to discuss quality assurance for LGK treatments; and to present examples of diagnoses treated by LGK. The following topics were discussed: Radiosurgery - definition, components of selectivity, fundamentals; Leksell gamma knife - principles; Stereotactic target localization; Radiosurgery - imaging; Treatment planning; LGK treatment; Quality control - process tree, LGK, distortion of scanners, 3D phantom measurements; Physical and technical parameters; and Clinical applications. (P.A.)

  2. Nuclear fuel microsphere gamma analyzer

    Science.gov (United States)

    Valentine, Kenneth H.; Long, Jr., Ernest L.; Willey, Melvin G.

    1977-01-01

    A gamma analyzer system is provided for the analysis of nuclear fuel microspheres and other radioactive particles. The system consists of an analysis turntable with means for loading, in sequence, a plurality of stations within the turntable; a gamma ray detector for determining the spectrum of a sample in one section; means for analyzing the spectrum; and a receiver turntable to collect the analyzed material in stations according to the spectrum analysis. Accordingly, particles may be sorted according to their quality; e.g., fuel particles with fractured coatings may be separated from those that are not fractured, or according to other properties.

  3. Investigation of gamma spectra analysis

    International Nuclear Information System (INIS)

    During the investigation of radiation fingerprint comparison, it is found out that the popular gamma spectra analysis softwares are faultful, which decrease the precision of radiation fingerprint comparison. So a new analysis software is development for solving the problems. In order to display the advantage of new program, some typical simulative gamma spectra of radiation source are analyzed respectively by our software and GAMMAVISION and GENNIE2000. The software can be applied not only in nuclear warheads deep-cuts verification, but also in any radiation measurement field. (authors)

  4. Gamma-ray Imaging Methods

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, K; Mihailescu, L; Nelson, K; Valentine, J; Wright, D

    2006-10-05

    In this document we discuss specific implementations for gamma-ray imaging instruments including the principle of operation and describe systems which have been built and demonstrated as well as systems currently under development. There are several fundamentally different technologies each with specific operational requirements and performance trade offs. We provide an overview of the different gamma-ray imaging techniques and briefly discuss challenges and limitations associated with each modality (in the appendix we give detailed descriptions of specific implementations for many of these technologies). In Section 3 we summarize the performance and operational aspects in tabular form as an aid for comparing technologies and mapping technologies to potential applications.

  5. Measurement of resonance production in the reactions. gamma. gamma. yields. pi. sup 0. pi. sup 0 and. gamma. gamma. yields. pi. sup 0. eta

    Energy Technology Data Exchange (ETDEWEB)

    Oest, T.; Greenshaw, T.; Hagemann, J.; Heinzelmann, G.; Kleinwort, C.; Kuhlen, M.; Naroska, B.; Ould-Saada, F.; Pitzl, D.; Schneekloth, U.; Weber, G. (Hamburg Univ. (Germany, F.R.). 2. Inst. fuer Experimentalphysik); Olsson, J.; Bartel, W.; Felst, R.; Haidt, D.; Kado, H.; Knies, G.; Krehbiel, H.; Magnussen, N.; Meinke, R.; Ramcke, R.; Schmidt, D.; Steffen, P. (Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany, F.R.)); Allison, J.; Barlow, R.J.; Chrin, J.; Duerdoth, I.P.; Loebinger, F.K.; Macbeth, A.A.; Murphy, P.G.; Stephens, K. (Manchester Univ. (UK)); Ambrus, K.; Bethke, S.; Dieckmann, A.; Eckerlin, G.; Elsen, E.; Heintze, J.; Hellenbrand, K.H.; Komamiya, S.; Krogh, J. v.; Rieseberg, H.; Smolik, L.; Spitzer, J.; Wagner, A.; Zimmer, M. (Heidelberg Univ. (Germany, F.R.). Physikalisches Inst.); Bowdery, C.K.; Finch, A.J.; Foster, F.; Hughes, G.; Nye, J.M.; Walker, I.W. (Lancaster Univ. (UK)); Cartwright, S.L.; Clarke, D.; Marshall, R.; Middleton, R.P. (Rutherford Appleton L; JADE Collaboration

    1990-07-01

    Resonance production in the {gamma}{gamma} reactions e{sup +}e{sup -}{yields}e{sup +}e{sup -}{pi}{sup 0}{pi}{sup 0} and e{sup +}e{sup -}{yields}e{sup +}e{sup -}{pi}{sup 0}{eta} has been studied with the JADE detector at PETRA. The decay widths into {gamma}{gamma} of the f{sub 2}(1270), {alpha}{sub 0}(980) and {alpha}{sub 2}(1320) were measured to be {Gamma}{sub {gamma}{gamma}}(f{sub 2}(1270))=3.19{plus minus}0.09(+.22-0.38) keV, {Gamma}{sub {gamma}{gamma}}(a{sub 0}(980))=0.28{plus minus}0.04{plus minus}0.10 keV/BR(a{sub 0}(980){yields}{pi}{sup 0}{eta}) and {Gamma}{sub {gamma}{gamma}}(a{sub 2}(1320))=1.01{plus minus}0.14{plus minus}0.22 keV. For the f{sub 0}(975) and f{sub 4}(2050) upper limits of the widths were obtained, {Gamma}{sub {gamma}{gamma}}(f{sub 0}(975))<0.6 keV and {Gamma}{sub {gamma}{gamma}}(f{sub 4}(2050))<1.1 keV, both at the 95% C.L. Assumming that the spin 0 background under the f{sub 2}(1270) is small, the f{sub 2}(1270) was found to be produced exclusively in a helicity 2 state. The helicity 0 contribution is <15% at the 95% C.L.. The cross section for {gamma}{gamma}{yields}{pi}{sup 0}{pi}{sup 0} in the mass range 2.0-3.5 GeV/c{sup 2} was measured for the first time. Since the cross section for {gamma}{gamma}{yields}{pi}{sup +}{pi}{sup -} is a factor {proportional to}2 larger, {pi}{pi} production in this range can be interpreted as taking place via isospin 0 production. (orig.).

  6. Recombinant interferon-gamma (rIFN-gamma) in dermatology.

    Science.gov (United States)

    Mahrle, G; Schulze, H J

    1990-12-01

    This paper gives a short review on the function, pharmacokinetics, and therapeutic application of recombinant interferon-gamma (rIFN-gamma) in dermatology. Simultaneously, our own experiences are presented for 57 patients (phase II study) suffering from genital warts (21 patients), psoriatic arthritis (10 patients), psoriasis vulgaris (three patients), malignant melanoma (six patients), bowenoid papulosis (four patients), Behcet's disease (four patients), basal cell carcinoma (six patients), as well as herpes simplex recidivans, epidermodysplasia verruciformis, and mycosis fungoides (one patient each). We conclude that there might be an indication for treatment with rIFN-gamma in genital warts, bowenoid papulosis, Behcet's disease, and microbial infections, such as leprosy and cutaneous leishmaniasis. Even though there are reports of a limited beneficial effect of rIFN-gamma on arthritis and skin lesions in psoriasis, we failed to observe any in 10 patients. The main side effects in our low-dose study (50-100 micrograms/d) were mild fever (78%), fatigue (78%), and myalgia (65%). Laboratory tests revealed an increase in the serum triglyceride level, in particular, in psoriatic patients. PMID:2124242

  7. Realization of a gamma multiplicity filter and gamma multiplicity measurements

    International Nuclear Information System (INIS)

    A gamma multiplicity filter for the study of reaction mechanism has been realised. It's composed of six NaI(Tl) counters. The flexibility of the geometry allows many configurations. This set up has been tested with gamma radioactive sources and with the 252Cf source to resolve problems of gamma-efficiency of the NaI(Tl) counters and the contamination of neutrons in these detectors. A logical electronic unit (Encodeur) has been constructed and the around electronic has been developped. This gamma multiplicity filter has been coupled with a detector of high resolution Ge(Li), and used in two reactions: 12C + 55Mn at E(12C) = 54 MeV; α + 63Cu at E(α) = 52 MeV. The dominant process is the fusion-evaporation. The compound nucleus 67Ga, is formed at the same excitation energy. The values of multiplicities Msub(γ) have been extracted using a program based on the formalism of W.J. Ockels. The fractionalization of the angular momentum is well observed for some residual nuclei (63Zn, 64Zn, 65Zn), and for each residual nucleus, the average gamma multiplicity is lower with projectile α than that with projectile 12C. For the most strongly output channel p2n, an entry point for the 64Zn has been determined in the reactions. All these observations are in good agreement with those published, in the same region (f-p shell) of nuclei. This set up can be coupled with different central detector as, ''X'', neutrons charged particles detectors, and will be used with the new machine SARA to make a systematic study of transfer of angular momentum to the fragments at 30 MeV/A

  8. Higgs boson decays into {\\gamma}{\\gamma} and Z{\\gamma} in the MSSM and BLSSM

    CERN Document Server

    Hammad, A; Moretti, S

    2015-01-01

    We calculate Higgs decay rates into {\\gamma}{\\gamma} and Z{\\gamma} in the Minimal Supersymmetric Standard Model (MSSM) and (B-L) Supersymmetric Standard Model (BLSSM) by allowing for contributions from light staus and charginos. We show that sizable departures are possible from the SM predictions for the 125 GeV state and that they are testable during run 2 at the Large Hadron Collider. Furthermore, we illustrate how a second light scalar Higgs signal in either or both these decay modes can be accessed at the CERN machine rather promptly within the BLSSM, a possibility instead precluded to the MSSM owing to the much larger mass of its heavy scalar state.

  9. The Gamma-ray Sky with Fermi

    CERN Document Server

    Thompson, D J

    2013-01-01

    Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as clusters of galaxies. Some results include a stringent limit on Lorentz invariance violation derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure in the direction of the center of our Galaxy, and strong constraints on some Weakly Interacting Massive Particle (WIMP) models for dark matter.

  10. Gamma-Ray Interactions for Reachback Analysts

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Myers, Steven Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-02

    This presentation is a part of the DHS LSS spectroscopy training course and presents an overview of the following concepts: identification and measurement of gamma rays; use of gamma counts and energies in research.

  11. Gravitational microlensing of gamma-ray blazars

    DEFF Research Database (Denmark)

    F. Torres, Diego; E. Romero, Gustavo; F. Eiroa, Ernesto;

    2003-01-01

    We present a detailed study of the effects of gravitational microlensing on compact and distant $\\gamma$-ray blazars. These objects have $\\gamma$-ray emitting regions which are small enough as to be affected by microlensing effects produced by stars lying in intermediate galaxies. We analyze the...... galactic latitude whose gamma-ray statistical properties are very similar to detected $\\gamma$-ray blazars) are indeed the result of gravitational lensing magnification of background undetected Active Galactic Nuclei (AGNs)....

  12. Gamma flicker triggers attentional selection without awareness

    OpenAIRE

    Bauer, F.(DSM/IRFU (Institut de Recherches sur les Lois Fondamentales de l’Univers), CEA Saclay (Commissariat à l’Energie Atomique et aux Energies Alternatives), Gif-sur-Yvette, France); Cheadle, SW; Parton, A; Mueller, HJ; Usher, M

    2009-01-01

    Gamma band modulations in neural activity have been proposed to mediate attentional processes. To support a causal link between gamma activity and attentional selection, we attempt to evoke gamma oscillations by a 50-Hz subliminal flicker. We find that a subliminal 50-Hz flicker at a target location, before target presentation, speeds up and enhances target detection and discrimination. This effect is specific to the middle of the gamma range because it is not evident at

  13. Search for Anomalous $ZZ\\gamma$ and $Z\\gamma\\gamma$ couplings in the process $e^{+}e^{-} \\to Z\\gamma$ at LEP

    CERN Document Server

    Acciarri, M; Adriani, O; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, L; Balandras, A; Baldew, S V; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brigljevic, V; Brochu, F; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Cucciarelli, S; Dai, T S; van Dalen, J A; D'Alessandro, R; De Asmundis, R; Déglon, P L; Degré, A; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Dufournaud, D; Duinker, P; Durán, I; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Extermann, Pierre; Fabre, M; Faccini, R; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Hofer, H; Holzner, G; Hoorani, H; Hou, S R; Hu, Y; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Khan, R A; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lassila-Perini, K M; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Lugnier, L; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Marchesini, P A; Marian, G; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Molnár, P; Moulik, T; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Organtini, G; Oulianov, A; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Paramatti, R; Park, H K; Park, I H; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Raspereza, A V; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Rubio, Juan Antonio; Ruggiero, G; Ruschmeier, D; Rykaczewski, H; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Sciarrino, D; Seganti, A; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Suter, H; Swain, J D; Szillási, Z; Sztaricskai, T; Tang, X W; Tauscher, Ludwig; Taylor, L; Tellili, B; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, M; Wang, X L; Wang, Z M; Weber, A; Weber, M; Wienemann, P; Wilkens, H; Wu, S X; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhu, G Y; Zhu, R Y; Zichichi, A; Zilizi, G; Zöller, M

    2000-01-01

    We search for anomalous trilinear gauge couplings in the ${\\rm ZZ}\\gamma$ and ${\\rm Z}\\gamma\\gamma$ vertices using data collected with the L3 detectorat LEP at a centre--of--mass energy $\\sqrt{s}=189$ GeV. No evidence is found and limits on these couplings and on new physics scales are derived from the analysis of the process ${\\rm e}^{+}{\\rm e}^{-} \\rightarrow {\\rm Z} \\gamma$.

  14. On $\\gamma N \\to \\gamma \\rho N'$ at large $\\gamma \\rho$ invariant mass

    CERN Document Server

    Boussarie, R; Szymanowski, L; Wallon, S

    2015-01-01

    Photoproduction of a pair of particles with large invariant mass is a natural extension of collinear QCD factorization theorems which have been much studied for deeply virtual Compton scattering and deeply virtual meson production. We consider the case where the wide angle Compton scattering subprocess $\\gamma (q\\bar q) \\to \\gamma \\rho $ factorizes from generalized parton distribution. At dominant twist, separating the transverse (respectively longitudinal) polarization of the $\\rho$ meson allows one to get access to chiral-odd (respectively chiral-even) GPDs. This opens a new way to the extraction of these elusive transversity GPDs.

  15. Gamma and X 93 spectrometry

    International Nuclear Information System (INIS)

    The Meetings of Gamma and X 93 Spectrometry were held on 12-14 October 1993. The symposium was organized into six sessions: Instrumentation development, Nuclear matter measurement, Method and calibration, Medical applications, Environment survey (radioactive traces measurement), other applications (spent fuels analysis, various techniques). Separate abstracts were prepared for all the papers in this volume. (TEC)

  16. The GRAD gamma ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Rester, A.C.; Piercey, R.B.; Eichhorn, G.; Coldwell, R.L.; McKisson, J.M.; Ely, D.W.; Mann, H.M.; Jenkins, D.A.

    1986-02-01

    A gamma-ray spectrometer for an upcoming space shuttle mission is described. Consisting of a 150 cm/sup 3/ n-type germanium detector set inside active shielding of bismuth germanate and plastic scintillator, the instrument will be used in studies of the Orbiter background and the galactic center.

  17. The GRAD gamma ray spectrometer

    International Nuclear Information System (INIS)

    A gamma-ray spectrometer for an upcoming space shuttle mission is described. Consisting of a 150 cm3 n-type germanium detector set inside active shielding of bismuth germanate and plastic scintillator, the instrument will be used in studies of the Orbiter background and the galactic center

  18. Gamma scanner conceptual design report

    International Nuclear Information System (INIS)

    The Fuels and Materials Examination Facility (FMEF) will include several stations for the nondestructive examination of irradiated fuels. One of these stations will be the gamma scanner which will be employed to detect gamma radiation from the irradiated fuel pins. The conceptual design of the gamma scan station is described. The gamma scanner will use a Standard Exam Stage (SES) as a positioner and transport mechanism for the fuel pins which it will obtain from a magazine. A pin guide mechanism mounted on the face of the collimator will assure that the fuel pins remain in front of the collimator during scanning. The collimator has remotely adjustable tungsten slits and can be manually rotated to align the slit at various angles. A shielded detector cart located in the operating corridor holds an intrinsic germanium detector and associated sodium-iodide anticoincidence detector. The electronics associated with the counting system consist of standard NIM modules to process the detector signals and a stand-alone multichannel analyzer (MCA) for counting data accumulation. Data from the MCA are bussed to the station computer for analysis and storage on magnetic tape. The station computer controls the collimator, the MCA, a source positioner and the SES through CAMAC-based interface hardware. Most of the electronic hardware is commercially available but some interfaces will require development. Conceptual drawings are included for mechanical hardware that must be designed and fabricated

  19. Short duration gamma ray bursts

    Indian Academy of Sciences (India)

    Patrick Das Gupta

    2004-10-01

    After a short review of gamma ray bursts (GRBs), we discuss the physical implications of strong statistical correlations seen among some of the parameters of short duration bursts (90 < 2 s). Finally, we conclude with a brief sketch of a new unified model for long and short GRBs.

  20. Nuclear magnetic gamma double resonance

    International Nuclear Information System (INIS)

    A number of problems corresponding to different variants of experiments using nuclear magnetic-gamma double resonance (NMGDR) are theoretically investigated. Calculation is carried out and its results are compared to experimental ones concerning NMGDR for tantalum. Time dynamics of the source or scatterer nucleus sublevel populations under double resonance conditions with non-uniform initial population of this nucleus sublevels is studied

  1. Gamma ray slush hydrogen monitor

    Science.gov (United States)

    Singh, Jag J.; Shen, Chih-Peng; Sprinkle, Danny R.

    1992-01-01

    Mass attenuation for 109Cd radiation have been measured in mixtures of phases and in single phases of five chemical compounds. As anticipated, the mass attenuation coefficients are independent of the phases of the test chemicals. It is recommended that a slush hydrogen monitoring system based on low energy gamma ray attenuation be developed for utilization aboard the NASP.

  2. Periodicities in gamma ray bursts

    International Nuclear Information System (INIS)

    Gamma ray burst models based on magnetic neutron stars face a problem of account for the scarcity of observed periods. Both this scarcity and the typical period found when any is detected are explained if the neutron stars are accreting in binary systems

  3. Gamma spectrometry of infinite 4Π geometry

    International Nuclear Information System (INIS)

    Owing to the weak absorption og gamma radiation by matter, gamma-ray spectrometry may be applied to samples of great volume. A very interesting case is that of the gamma-ray spectrometry applied with 4Π geometry around the detector on a sample assumed to be of infinite extension. The determination of suitable efficiencies allows this method to be quantitative. (author)

  4. Sterilization of pharmaceuticals by gamma ray

    International Nuclear Information System (INIS)

    This paper shows the possibility of sterilization of certain pharmaceuticals and materials involved by gamma radiation from cobalt-60 and cesium-137 sources, and illustrates the importance of gamma ray sterilization compared with other sterilization methods. The paper also reviews some pharmaceuticals and materials involved, which proved the possibility of gamma ray sterilization. (author)

  5. Energy spectrum of lightning gamma emission

    Energy Technology Data Exchange (ETDEWEB)

    Chubenko, A.P. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Karashtin, A.N. [Research Radiophysics Institute, Nizhny Novgorod (Russian Federation); Ryabov, V.A., E-mail: ryabov@x4u.lebedev.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shepetov, A.L. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Antonova, V.P.; Kryukov, S.V. [Ionosphere Institute, Almaty (Kazakhstan); Mitko, G.G.; Naumov, A.S.; Pavljuchenko, L.V. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Ptitsyn, M.O., E-mail: ptitsyn@lpi.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shalamova, S.Ya. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shlyugaev, Yu.V. [Research Radiophysics Institute, Nizhny Novgorod (Russian Federation); Vildanova, L.I. [Tien-Shan Mountain Cosmic Ray Station, Almaty (Kazakhstan); Zybin, K.P. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Gurevich, A.V., E-mail: alex@lpi.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation)

    2009-08-10

    The results of gamma emission observations obtained during thunderstorms at Tien-Shan Mountain Cosmic Ray Station are presented. The energy spectrum radiation of the stepped leader gamma radiation is measured. The total energy of stepped leader emitted in gamma rays is estimated as 10{sup -3}-10{sup -2} J. The experimental results are in an agreement with the runaway breakdown mechanism.

  6. Energy spectrum of lightning gamma emission

    International Nuclear Information System (INIS)

    The results of gamma emission observations obtained during thunderstorms at Tien-Shan Mountain Cosmic Ray Station are presented. The energy spectrum radiation of the stepped leader gamma radiation is measured. The total energy of stepped leader emitted in gamma rays is estimated as 10-3-10-2 J. The experimental results are in an agreement with the runaway breakdown mechanism.

  7. Gamma and Related Functions Generalized for Sequences

    Science.gov (United States)

    Ollerton, R. L.

    2008-01-01

    Given a sequence g[subscript k] greater than 0, the "g-factorial" product [big product][superscript k] [subscript i=1] g[subscript i] is extended from integer k to real x by generalizing properties of the gamma function [Gamma](x). The Euler-Mascheroni constant [gamma] and the beta and zeta functions are also generalized. Specific examples include…

  8. Airbornesystem for gamma spectrometry and gamma-background mapping

    International Nuclear Information System (INIS)

    Gamma radiation has the greatest penetrating power from natural and artificial (man-made) sources, and the spectroscopy of gamma rays is a powerful tool for the monitoring and evaluation of the radiation background in a given area. It is possible that these observations be carried out from aircraft and ground vehicles, covering large areas of the Earth‘s surface by compiling national and regional radiometric maps. Maps of ground radioactivity and concentrations of radionuclides can be thus compared and regional grouped by highlighting trends common to a given area with regard to the distribution of radionuclides, a powerful tool for radioecological analysis. Gamma-background surveying and mapping surveys allows for the interpretation of the regional traits of large areas. Such studies can be used to evaluate the dose burden from ground radioactivity to the human population in a given area as well as for highlighting areas of elevated natural background activity presenting additional radiological and radiobiological risk.The expert team of the Theta-Consult Ltd., Sofia can and have already carried out studies through the company-owned air-mobile spectrometric system for radiation monitoring of the environment and gamma mapping. The results represent the most up-to-date surveys of this kind in the country with quality and precision of the measurements repeatedly exceeding the previous best results of airborne gamma mapping in the country from 10–20 years ago. The system we use (SPIR-Ident Mobile, Mirion Technologies, 2013) is designed for use in land vehicles, helicopters and airplanes.The equipment is impact and vibration-resistant and easy to deploy while retaining the highest available capacities and lowest detection limits for location and identification of radioactive sources. This system specifically allows the detection of technogenic radionuclides on a background consisting of a variety of naturally radioactive isotopes allowing the use of the air

  9. Branching Fraction Measurements of B+ -> rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma

    CERN Document Server

    Aubert, B; Abrams, G S; Adye, T; Ahmed, S; Alam, M S; Albert, J; Aleksan, R; Allen, M T; Allison, J; Altenburg, D D; Andreotti, M; Angelini, C; Anulli, F; Arnaud, N; Asgeirsson, D J; Aston, D; Azzolini, V; Baak, M A; Back, J J; Baldini-Ferroli, R; Band, H R; Banerjee, Sw; Bard, D J; Barlow, N R; Barlow, R J; Barrett, M; Bartoldus, R; Batignani, G; Battaglia, M; Bauer, J M; Bechtle, P; Beck, T W; Behera, P K; Bellini, F; Ben-Haim, E; Benelli, G; Berger, N; Bernard, D; Berryhill, J W; Bettarini, S; Bettoni, D; Bevan, A J; Bhuyan, B; Bianchi, F; Biasini, M; Biesiada, J; Blanc, F; Blaylock, G; Blinov, V E; Bloom, P C; Blount, N L; Bomben, M; Bondioli, M; Bonneaud, G R; Bosisio, L; Boutigny, D; Boyd, J T; Bozzi, C; Brandt, T; Brau, J E; Briand, H; Brown, D N; Bruinsma, M; Brunet, S; Buchanan, C; Bugg, W; Bukin, A D; Bula, R; Burchat, P R; Burke, J P; Button-Shafer, J; Buzzo, A; Bóna, M; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Carpinelli, M; Cartaro, C; Castelli, G; Cavallo, N; Cavoto, G; Cenci, R; Chai, X; Chaisanguanthum, K S; Chao, M; Charles, M J; Chauveau, J; Chavez, C A; Chen, A; Chen, C; Chen, E; Chen, J C; Chen, S; Chen, X; Chen, X R; Cheng, C H; Chia, Y M; Cibinetto, G; Clark, P J; Claus, R; Cochran, J; Coleman, J P; Contri, R; Convery, M R; Corwin, L A; Cossutti, F; Cottingham, W N; Covarelli, R; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L; Cunha, A; Curry, S; Côté, D; D'Orazio, A; Dahmes, B; Dallapiccola, C; Dasu, S; Dauncey, P D; David, P; Davier, M; Davis, C L; De Nardo, Gallieno; De Sangro, R; Del Amo-Sánchez, P; Del Buono, L; Del Re, D; Della Ricca, G; Denig, A G; Di Lodovico, F; Di Marco, E; Dingfelder, J C; Dong, L; Dorfan, J; Druzhinin, V P; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Dvoretskii, A; Ebert, M; Eckhart, E A; Eckmann, R; Edgar, C L; Edwards, A J; Eigen, G; Eisner, A M; Elmer, P; Emery, S; Ernst, J A; Escalier, M; Eschenburg, V; Eschrich, I; Eyges, V; Fabozzi, F; Faccini, R; Fang, F; Feltresi, E; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Flacco, C J; Flack, R L; Flächer, H U; Flood, K T; Ford, W T; Forster, I J; Forti, F; Foulkes, S D; Franek, B; Frey, R; Fritsch, M; Fry, J R; Fulsom, B G; Gabathuler, E; Gaidot, A; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gary, J W; Gaspero, M; Gatto, C; Gaz, A; George, K A; Giorgi, M A; Gladney, L; Glanzman, T; Godang, R; Golubev, V B; Gowdy, S J; Gradl, W; Graham, M T; Graugès-Pous, E; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Haire, M; Halyo, V; Hamano, K; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, A J; Hartfiel, B L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hill, E J; Hirschauer, J F; Hitlin, D G; Hollar, J J; Hong, T M; Honscheid, K; Hopkins, D A; Hrynóva, T; Hufnagel, D; Hulsbergen, W D; Hutchcroft, D E; Höcker, A; Igonkina, O; Innes, W R; Izen, J M; Jackson, P D; Jackson, P S; Jacobsen, R G; Jain, V; Jasper, H; Jawahery, A; Jessop, C P; Kadyk, J A; Kagan, H; Karyotakis, Yu; Kass, R; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Klose, V; Knecht, N S; Koch, H; Koeneke, K; Kolb, J A; Kolomensky, Yu G; Kovalskyi, D; Kowalewski, R V; Kozanecki, W; Kreisel, A; Krishnamurthy, M; Kroeger, R; Kroseberg, J; Kukartsev, G; Kutter, P E; Kyberd, P; La Vaissière, C de; Lacker, H M; Lae, C K; Lafferty, G D; Lanceri, L; Lang, M I; Lange, D J; Lankford, A J; Latham, T E; Latour, E; Lau, Y P; Lazzaro, A; Le Diberder, F R; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Lewandowski, B; Li Gioi, L; Li, S; Li, X; Lista, L; Liu, F; Liu, H; Lo Vetere, M; LoSecco, J M; Lockman, W S; Lombardo, V; Long, O; Lopes-Pegna, D; Lopez-March, N; Lou, X C; Lu, M; Luitz, S; Lund, P; Luppi, E; Lusiani, A; Lutz, A M; Lynch, G; Lynch, H L; Lü, C; Lüth, V; MacFarlane, D B; Macri, M M; Mader, W F; Majewski, S A; Malcles, J; Mallik, U; Mancinelli, G; Mandelkern, M A; Marchiori, G; Margoni, M; Marks, J; Marsiske, H; Martin, E C; Martínez-Vidal, F; Mattison, T S; Mazur, M A; Mazzoni, M A; McKenna, J A; McMahon, T R; Mclachlin, S E; Meadows, B T; Mellado, B; Menges, W; Merkel, J; Messner, R; Meyer, N T; Meyer, W T; Mir, L M; Mishra, K; Mohanty, G B; Monge, M R; Monorchio, D; Moore, T B; Morandin, M; Morganti, M; Morganti, S; Morii, M; Morris, J P; Muheim, F; Müller, D R; Nagel, M; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nicholson, H; Nikolich, M B; Nogowski, R; Nugent, I M; O'Grady, C P; Ocariz, J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Oyanguren, A; Ozcan, V E; Paar, H P; Pacetti, S; Palano, A; Palombo, F; Pan, B; Pan, Y; Panduro-Vazquez, W; Paoloni, E; Paolucci, P; Pappagallo, M; Park, W; Passaggio, S; Patel, P M; Patrignani, C; Patteri, P; Payne, D J; Pelizaeus, M; Pelliccioni, M; Perazzo, A; Perl, M; Peruzzi, I M; Peters, K; Petersen, B A; Petrella, A; Petzold, A; Piatenko, T; Piccolo, D; Piccolo, M; Piemontese, L; Pierini, M; Piredda, G; Playfer, S; Poireau, V; Polci, F; Pompili, A; Porter, F C; Posocco, M; Potter, C T; Prell, S; Prencipe, E; Prepost, R; Pripstein, M; Prudent, X; Pruvot, S; Pulliam, T; Purohit, M V; Qi, N D; Rahatlou, S; Rahimi, A M; Rahmat, R; Rama, M; Ratcliff, B N; Raven, G; Regensburger, J J; Ricciardi, S; Richman, J D; Ritchie, J L; Rizzo, G; Roberts, D A; Robertson, A I; Robertson, S H; Robutti, E; Rodier, S; Roe, N A; Ronan, M T; Roney, J M; Rong, G; Roodman, A; Rosenberg, E I; Rotondo, M; Roudeau, P; Rubin, A E; Röthel, W; Sacco, R; Saeed, M A; Saleem, M; Salnikov, A A; Salvati, E; Salvatore, F; Sanders, D A; Santroni, A; Saremi, S; Schalk, T; Schenk, S; Schilling, C J; Schindler, R H; Schofield, K C; Schott, G; Schröder, T; Schröder, H; Schubert, J; Schubert, K R; Schumm, B A; Schune, M H; Schwiening, J; Schwierz, R; Schwitters, R F; Sciacca, C; Sciolla, G; Seiden, A; Sekula, S J; Serednyakov, S I; Serrano, J; Sharma, V; Shen, B C; Sherwood, D J; Simard, M; Simi, G; Simonetto, F; Sinev, N B; Skovpen, Yu I; Smith, A J S; Smith, J G; Snoek, H L; Snyder, A; Sobie, R J; Soffer, A; Sokoloff, M D; Solodov, E P; Spaan, B; Spanier, S M; Spitznagel, M; Steinke, M; Stelzer, J; Stocchi, A; Stoker, D P; Stroili, R; Strom, D; Strube, J; Stugu, B; Su, D; Sullivan, M K; Summers, D J; Sundermann, J E; Suzuki, K; Swain, S K; Tackmann, K; Taras, P; Taylor, F; Telnov, A V; Teodorescu, L; Ter-Antonian, R; Thiebaux, C; Thompson, J M; Tisserand, V; Todyshev, K Yu; Toki, W H; Torrence, E; Tosi, S; Touramanis, C; Ulmer, K A; Uwer, U; Van Bakel, N; Vasseur, G; Vavra, J; Verderi, M; Viaud, F B; Vitale, L; Voci, C; Voena, C; Volk, A; Wacker, K; Wagner, A P; Wagner, S R; Waldi, R; Walker, D; Walsh, J J; Wang, P; Wang, W F; Wappler, F R; Watson, A T; Weaver, M; Wenzel, W A; West, T J; Wilden, L; Williams, D C; Wilson, F F; Wilson, J R; Wilson, M G; Wilson, R J; Winklmeier, F; Winstrom, L O; Wisniewski, W J; Wittgen, M; Wong, Q K; Wormser, G; Wren, A C; Wright, D H; Wright, D M; Wu, J; Wu, S L; Wulsin, H W; Xie, Y; Yamamoto, R K; Yarritu, A K; Ye, S; Yi, J I; Yi, K; Yi, M; Young, C C; Yu, Z; Yéche, C; Zain, S B; Zallo, A; Zeng, Q; Zghiche, A; Zhang, J; Zhang, L; Zhao, H W; Zhu, Y S; Ziegler, V; Zito, M; Çuhadar-Dönszelmann, T; al, et

    2006-01-01

    We present a study of the decays B+ -> rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma. The analysis is based on data containing 347 million BBbar events recorded with the BaBar detector at the PEP-II asymmetric B factory. We measure the branching fractions BR(B+ -> rho+ gamma) = (1.10 +0.37/-0.33 +/- 0.09) x 10-6 and BR(B0 -> rho0 gamma) = (0.79 +0.22/-0.20 +/- 0.06) x 10-6, and set a 90% C.L. upper limit BR(B0 -> omega gamma) rho/omega gamma) = (1.25 +0.25/-0.24 +/- 0.09) x 10-6, from which we determine |Vtd/Vts| = 0.200 +0.021/-0.020 +/- 0.015, where the first uncertainty is experimental and the second is theoretical.

  10. Transitional gamma strength in Cd isotopes

    OpenAIRE

    Larsen, André; Ruud, I. E.; Burger, Arnold; Goriely, Stéphane; Guttormsen, Magne; Görgen, Andreas; Hagen, W. T.; Harissopulos, Sotirios; Nyhus, Hilde Therese; Renstrom, T.; Schiller, Andreas; Siem, Sunniva; Tveten, G. M.; Voinov, A.; Wiedeking, M.

    2013-01-01

    The level densities and $\\gamma$-ray strength functions of $^{105,106,111,112}$Cd have been extracted from particle-$\\gamma$ coincidence data using the Oslo method. The level densities are in very good agreement with known levels at low excitation energy. The $\\gamma$-ray strength functions display no strong enhancement for low $\\gamma$ energies. However, more low-energy strength is apparent for $^{105,106}$Cd than for $^{111,112}$Cd. For $\\gamma$ energies above $\\approx$ 4 MeV, there is evid...

  11. Simultaneous neutron and gamma spectrum adjustment

    International Nuclear Information System (INIS)

    The spectrum adjustment procedure was extended to simultaneous neutron and gamma spectrum adjustment, and the feasibility of this technique is demonstrated in the analysis of HFIR dosimetry experiments. Conditions in which gamma rays may contribute considerably to radiation damage in steels are discussed. Beryllium helium accumulation fluence monitors (HAFMs) were found to be good monitors in gamma fields of intensities high enough to contribute to steel embrittlement. Use of 237Np, 238U, and 9Be HAFM as gamma dosimeters is proposed for high-dose irradiations in high-energy, high-intensity gamma fields

  12. Measurement of the gamma gamma* -> pi0 transition form factor

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.

    2009-06-02

    We study the reaction e{sup +}e{sup -} {yields} e{sup +}e{sup -}{pi}{sup 0} in the single tag mode and measure the differential cross section d{sigma}/dQ{sup 2} and the {gamma}{gamma}* {yields} {pi}{sup 0} transition form factor in the mometum transfer range from 4 to 40 GeV{sup 2}. At Q{sup 2} > 10 GeV{sup 2} the measured form factor exceeds the asymptotic limit predicted by perturbative QCD. The analysis is based on 442 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.

  13. Gamma-ray emission from thunderstorm discharges

    International Nuclear Information System (INIS)

    Fine features of gamma-ray radiation registered during a thunderstorm at Tien-Shan Mountain Cosmic Ray Station are presented. Long duration (100-600 ms) gamma-ray bursts are found. They are for the first time identified with atmospheric discharges (lighting). Gamma-ray emission lasts all the time of the discharge and is extremely non-uniform consisting of numerous flashes. Its peak intensity in the flashes exceeds the gamma-ray background up to two orders of magnitude. Exclusively strong altitude dependence of gamma radiation is found. The observation of gamma radiation at the height 4-8 km could serve as a new important method of atmospheric discharge processes investigation. - Highlights: → Gamma-radiation bursts always accompany the electric discharges in atmosphere. → The gamma burst fill up the time of an atmospheric discharge completely. → The higher is the discharge electric field change - the higher is gamma intensity. → The temporal distribution of gamma intensity during the burst is non-uniform. → The altitude dependence of the burst gamma intensity is dramatic.

  14. Gamma-ray emission from thunderstorm discharges

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, A.V., E-mail: alex@lpi.r [P. N. Lebedev Physical Institute, Moscow (Russian Federation); Chubenko, A.P. [P. N. Lebedev Physical Institute, Moscow (Russian Federation); Karashtin, A.N. [Radiophysical Research Institute, Nizhny Novgorod (Russian Federation); Mitko, G.G.; Naumov, A.S.; Ptitsyn, M.O.; Ryabov, V.A.; Shepetov, A.L. [P. N. Lebedev Physical Institute, Moscow (Russian Federation); Shlyugaev, Yu.V. [Radiophysical Research Institute, Nizhny Novgorod (Russian Federation); Vildanova, L.I. [Tien-Shan Mountain Cosmic Ray Station, Almaty (Kazakhstan); Zybin, K.P. [P. N. Lebedev Physical Institute, Moscow (Russian Federation)

    2011-04-11

    Fine features of gamma-ray radiation registered during a thunderstorm at Tien-Shan Mountain Cosmic Ray Station are presented. Long duration (100-600 ms) gamma-ray bursts are found. They are for the first time identified with atmospheric discharges (lighting). Gamma-ray emission lasts all the time of the discharge and is extremely non-uniform consisting of numerous flashes. Its peak intensity in the flashes exceeds the gamma-ray background up to two orders of magnitude. Exclusively strong altitude dependence of gamma radiation is found. The observation of gamma radiation at the height 4-8 km could serve as a new important method of atmospheric discharge processes investigation. - Highlights: Gamma-radiation bursts always accompany the electric discharges in atmosphere. The gamma burst fill up the time of an atmospheric discharge completely. The higher is the discharge electric field change - the higher is gamma intensity. The temporal distribution of gamma intensity during the burst is non-uniform. The altitude dependence of the burst gamma intensity is dramatic.

  15. Laser source for the gamma-gamma collider

    CERN Document Server

    Early, J T

    2001-01-01

    The production of high energy gammas from collisions between the NLC high energy electrons and low energy photons places difficult requirements on the laser low energy photon source. The electrons are produced in macro-pulses at 120 Hz. Each macro-pulse consists of around 100 subpulses separated by 2.8 nanoseconds. To interact efficiently with the electrons the laser subpulses must have approximately a 2 picosecond pulse duration. The laser macro-pulse energy must be 100 joules per beam at 120 Hz, or a total laser average power of 24 kW. The Mercury laser consists of a Yb:S-FAP laser instead of the usual Nd-glass as it has better thermal conductivity for cooling, longer storage lifetime for efficient pumping, and a high quantum efficiency to minimise waste heat. The laser will operate at 10 Hz with 100 J pulses. Twelve such laser would have to be multiplexed to achieve the gamma - gamma laser requirements. (2 refs).

  16. Urban gamma spectrometry. Report 2

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H. (Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2009-06-15

    Urban gamma spectrometry has been given only minor attention with the focus being on rural gamma spectrometry. However, in recent years the Nordic emergency management authorities have turned focus towards border control and lost or stolen sources. Gamma spectra measured in urban areas are characterized by a wide variety of spectrum shapes and very fast changes in environmental background. In 2004 a Danish CGS (Carborne Gamma Spectrometry) survey took place in Copenhagen. It was found that gamma spectrometry in urban areas is far more complicated to interpret than had previously been thought and a new method 'Fitting with Spectral Components', FSC, based on NASVD, was tested with some success. In Finland, a database 'LINSSI' has been developed for spectral data management. In CGS search mode a 'peak hypothesis test' is applied to the measured spectra. This system was tested during the Helsinki 2005 Athletics World Championship and it provides fast and reliable automated alarms for intermediate and high level signals. In Sweden mobile detector systems are used for border controls and problems are encountered when making measurement in harbour, container areas. The methods for handling data and for interpretation of urban gamma spectrometry measurements were compared and tested on the same data sets from Copenhagen and Helsinki. Software tools were developed for converting data between the Finnish LINSSI database and the binary file formats used in Denmark and Sweden. The Processing methods used at DTU and STUK have different goals. The ASSS and FSC methods are designed to optimize the overall detection capability of the system, while sacrificing speed, usability and to a certain level robustness. These methods cannot always be used for real time analysis. The Peak Significance method is designed to give robust alarms in real time, while sacrificing some of the detection capability. Thus these methods are not interchangeable, but rather

  17. Measurement of the $ \\mathrm{ Z } \\gamma \\rightarrow \

    Energy Technology Data Exchange (ETDEWEB)

    Khachatryan, Vardan; et al.

    2016-02-23

    A measurement of the Z gamma to nu nu-bar gamma production cross section in pp collisions at sqrt(s) = 8 TeV is presented, using data corresponding to an integrated luminosity of 19.6 inverse-femtobarns collected with the CMS detector at the LHC. This measurement is based on the observation of events with large missing energy and with a single photon with transverse momentum above 145 GeV and absolute pseudorapidity in the range |eta| < 1.44. The measured Z gamma to nu nu-bar gamma production cross section, 52.7 +/- 2.1(stat) +/- 6.4 (syst) +/- 1.4 (lumi) fb, agrees well with the standard model prediction of 50.0+2.4-2.2 fb. A study of the photon transverse momentum spectrum yields the most stringent limits to date on the anomalous Z-Z-gamma and Z-gamma-gamma trilinear gauge boson couplings.

  18. Prompt and Delayed Gamma-Rays from Fission

    International Nuclear Information System (INIS)

    The following data about gamma-rays from fission are reported and discussed; Total prompt gamma-ray spectrum, and average number and energy of gamma-rays; X-rays in prompt fission, and excitation of X-rays in matter; gamma-ray spectra as a function of the mass ratio in fission, gamma-lines in those spectra, and Doppler effect-, anisotropy in gamma-emission relative to the direction of fragments; average gamma-energy and gamma-spectra as a function of mass of the fission products; delayed gamma-rays; delayed gamma-rays as a function of fission product mass. (author)

  19. T cell receptor gamma/delta chain diversity

    OpenAIRE

    1988-01-01

    The TCR-gamma and -delta chains of six murine hybridomas were compared by one-dimensional SDS-PAGE and two-dimensional NEPHGE/SDS-PAGE analysis. This allowed the identification of three distinct gamma chains (gamma a, gamma b, and gamma c) and three distinct delta chains (delta a, delta b, and delta c). Four gamma/delta chain combinations (gamma a delta a, gamma b delta b, gamma b delta c, and gamma c delta a) were observed. These results indicate that multiple forms of the delta chain are ex...

  20. LEPS backward gamma detector reassembled

    International Nuclear Information System (INIS)

    A new electro-magnetic (EM) calorimeter complex FOREST covering a solid angle of about 4π sr is under construction. It consists of three calorimeters: the EPS forward one made up of pure CsI crystals, the middle one of lead scintillating fiber (Lead/SciFi) modules, and the backward one of lead glass Cerenkov counters. We have reassembled the middle calorimeter, comprised of 252 Lead/SciFi modules, which used to be the LEPS Backward Gamma detector system utilized in a LEPS experiment at SPring-8. A performance test for the gamma detector system has been made with a photon beam in the GeV γ experimental hall. The π0 peak is clearly observed in the γγ invariant mass distribution. (author)

  1. Airborne gamma ray spectrometer surveying

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) in its role as collector and disseminator of information on nuclear techniques has long had an interest in gamma ray spectrometer methods and has published a number of Technical Reports on various aspects of the subject. At an Advisory Group Meeting held in Vienna in November 1986 to review appropriate activities the IAEA could take following the Chernobyl accident, it was recommended that preparation begin on a new Technical Report on airborne gamma ray spectrometer surveying, taking into account the use of the technique for environmental monitoring as well as for nuclear emergency response requirements. Shortly thereafter the IAEA became the lead organization in the Radioelement Geochemical Mapping section of the International Geological Correlation Programme/United Nations Educational, Scientific and Cultural Organization (UNESCO) Project on International Geochemical Mapping. These two factors led to the preparation of the present Technical Report. 18 figs, 4 tabs

  2. Gamma irradiators: developments in India

    International Nuclear Information System (INIS)

    A comprehensive programme for the production of 60Co sources and their applications was initiated at the Bhabha Atomic Research Centre in 1970. Initially a series of research irradiators called Gamma Chambers and Panoramic Batch Irradiators (PANBITs) was fabricated for R and D and pilot scale studies. In 1974 the first commercial scale, gamma sterilization plant ISOMED was commissioned with UNDP assistance. Subsequently two more plants were designed and built indigenously, one at Bangalore and the other at Delhi. A radiation plant for sludge hygienisation was built at Baroda and commissioned in 1992. The current interest in radiation vulcanization of natural rubber latex (NRL) prompted the development and commissioning of a pilot scale NRL, irradiator at Kottayam, Kerala in 1992. A multipurpose irradiator is built recently at Jodhpur, as an upgraded version of the vintage PANBIT. Salient feature of these plants are presented . (author). 6 figs

  3. Compton suppression gamma ray spectrometry

    International Nuclear Information System (INIS)

    In the past decade there have been many studies to use Compton suppression methods in routine neutron activation analysis as well as in the traditional role of low level gamma ray counting of environmental samples. On a separate path there have been many new PC based software packages that have been developed to enhance photopeak fitting. Although the newer PC based algorithms have had significant improvements, they still suffer from being effectively used in weak gamma ray lines in natural samples or in neutron activated samples that have very high Compton backgrounds. We have completed a series of experiments to show the usefulness of Compton suppression. As well we have shown the pitfalls when using Compton suppression methods for high counting deadtimes as in the case of neutron activated samples. We have also investigated if counting statistics are the same both suppressed and normal modes. Results are presented in four separate experiments. (author)

  4. Thermodynamic condition for ''Gamma'' flotation

    International Nuclear Information System (INIS)

    Using the definition of the critical surface tension of wetting solids (Γc) and Gibb's adsorption isotherm, coupled with Young-Dupre's equation, the equilibrium thermodynamic condition for 'GAMMA' flotation has been derived. It is defined by the relation, Cos Oe=Γc/Γlg. At equilibrium for 'Gamma' flotation to occur, the liquid/gas interfacial tension (9γlg) should be larger than the critical surface tension of wetting of the solid surface, meaning that the equilibrium contact angle (Oe) should be greater than Zero, or cos Oe < 1, a Pre- requisite for the solid/gas bubble attachment. This definition holds for solid surfaces in the absence of any specific adsorption at the solid/liquid and solid/gas inter faces. Contact angle and flotation data are presented to sustain this definition. (author)., 15 refs., 9 figs

  5. The effect of 60Co gamma radiation on human serum gamma-globulin

    International Nuclear Information System (INIS)

    The effect of 60Co gamma radiation on human serum gamma-globulin was studied in vitro experiments. Solutions of 0.5 percent gamma-globulin were exposed to 0.2, 0.5, 1.0 and 1.9 Mrad doses 60Co gamma irradiation. Experiments showed that electrophoretic mobility of serum gamma-globulin decreased after gamma irradiation. No significant change in gamma-globulin UV absorption spectrum was observed at 0.2, 0.5, 1.0 and 1.9 Mrad doses. Gamma-globulin becomes progressively less soluble in water as the radiation doses is increased. Radiation induced transformation into insoluble gamma-globulin agregates and scission products. (author)

  6. Gamma sterilization of perfumed talcs

    International Nuclear Information System (INIS)

    Formula of talcs powders manufactured in cosmetic industry often includes starch and therefore they cannot be sterilized by ordinary dry heat processes. Gamma ray are most convenient, but one might expect a resulting adulteration of perfume, if present in the item. Contrarely, it was found that no modification seemed to occur, in the scent of the sterilized product. Increase of stability, after long storage, was even observed

  7. Supernovae and Gamma Ray Bursts

    Directory of Open Access Journals (Sweden)

    M. Della Valle

    2007-01-01

    Full Text Available Se revisa el estatus observacional de la conexi on Supernova (SN/Estallido de Rayos-Gamma (GRB. Recientes (y no tan recientes observaciones de GRBs largos sugieren que una fracci on signi cativa de ellos (pero no todos est an asociados con supernovas brillantes del tipo Ib/c. Estimaciones actuales de las tasas de producci on de GRBs y SNs dan una raz on para GRB/SNe-Ibc en el rango 0:4%

  8. Monomial Gamma Monte Carlo Sampling

    OpenAIRE

    Zhang, Yizhe; Wang, Xiangyu; Chen, Changyou; Fan, Kai; Carin, Lawrence

    2016-01-01

    We unify slice sampling and Hamiltonian Monte Carlo (HMC) sampling by demonstrating their connection under the canonical transformation from Hamiltonian mechanics. This insight enables us to extend HMC and slice sampling to a broader family of samplers, called monomial Gamma samplers (MGS). We analyze theoretically the mixing performance of such samplers by proving that the MGS draws samples from a target distribution with zero-autocorrelation, in the limit of a single parameter. This propert...

  9. Neutrinos from Gamma Ray Bursts

    CERN Document Server

    Mannheim, K

    2000-01-01

    The observed fluxes of cosmic rays and gamma rays are used to infer the maximum allowed high-energy neutrino flux allowed for Gamma Ray Bursts (GRBs), following Mannheim, Protheroe, and Rachen (2000). It is shown that if GRBs produce the ultrahigh-energy cosmic rays, they should contribute (a) at least 10% of the extragalactic gamma ray background between 3 MeV and 30 GeV, contrary to their observed energy flux which is only a minute fraction of this flux, and (b) a cumulative neutrino flux a factor of 20 below the AMANDA (Neutrino 2000) limit on isotropic neutrinos. This could have two implications, either GRBs do not produce the ultrahigh energy cosmic rays or that the GRBs are strongly beamed and emit most of their power at energies well above 100 GeV implausibly increasing the energy requirements, but consistent with the marginal detections of a few low-redshift GRBs by MILAGRITO, HEGRA-AIROBICC, and the Tibet-Array. All crucial measurements to test the models will be available in the next few years. Thes...

  10. Growth kinetics of gamma-prime precipitates in a directionally solidified eutectic, gamma/gamma-prime-delta

    Science.gov (United States)

    Tewari, S. N.

    1976-01-01

    A directionally solidified eutectic alloy (DSEA), of those viewed as potential candidates for the next generation of aircraft gas turbine blade materials, is studied for the gamma-prime growth kinetics, in the system Ni-Nb-Cr-Al, specifically: Ni-20 w/o Nb-6 w/o Cr-2.5 w/o Al gamma/gamma-prime-delta DSEA. Heat treatment, polishing and etching, and preparation for electron micrography are described, and the size distribution of gamma-prime phase following various anneals is plotted, along with gamma-prime growth kinetics in this specific DSEA, and the cube of gamma-prime particle size vs anneal time. Activation energies and coarsening kinetics are studied.

  11. Evidence for $\\eta_{c} \\rightarrow \\gamma\\gamma$ and Measurement of $J/\\psi\\rightarrow 3\\gamma$

    CERN Document Server

    Ablikim, M; Ambrose, D J; An, F F; An, Q; An, Z H; Bai, J Z; Ban, Y; Becker, J; Bertani, M; Bian, J M; Boger, E; Bondarenko, O; Boyko, I; Briere, R A; Bytev, V; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, J C; Chen, M L; Chen, S J; Chen, Y B; Cheng, H P; Chu, Y P; Cronin-Hennessy, D; Dai, H L; Dai, J P; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; Ding, W M; Ding, Y; Dong, L Y; Dong, M Y; Du, S X; Fang, J; Fang, S S; Fava, L; Feldbauer, F; Feng, C Q; Ferroli, R B; Fu, C D; Fu, J L; Gao, Y; Geng, C; Goetzen, K; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, Y P; Han, Y L; Harris, F A; He, K L; He, M; He, Z Y; Held, T; Heng, Y K; Hou, Z L; Hu, H M; Hu, J F; Hu, T; Huang, G M; Huang, J S; Huang, X T; Huang, Y P; Hussain, T; Ji, C S; Ji, Q; Ji, X B; Ji, X L; Jiang, L L; Jiang, X S; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Jing, F F; Kalantar-Nayestanaki, N; Kavatsyuk, M; Kuehn, W; Lai, W; Lange, J S; Li, C H; Li, Cheng; Li, Cui; Li, D M; Li, F; Li, G; Li, H B; Li, J C; Li, K; Li, Lei; Li, Q J; Li, S L; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, X R; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Liao, X T; Liu, B J; Liu, C L; Liu, C X; Liu, C Y; Liu, F H; Liu, Fang; Liu, Feng; Liu, H; Liu, H B; Liu, H H; Liu, H M; Liu, H W; Liu, J P; Liu, K Y; Liu, Kai; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, X H; Liu, Y B; Liu, Z A; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H; Lu, G R; Lu, H J; Lu, J G; Lu, Q W; Lu, X R; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lv, M; Ma, C L; Ma, F C; Ma, H L; Ma, Q M; Ma, S; Ma, T; Ma, X Y; Ma, Y; Maas, F E; Maggiora, M; Malik, Q A; Mao, Y J; Mao, Z P; Messchendorp, J G; Min, J; Min, T J; Mitchell, R E; Mo, X H; Morales, C Morales; Motzko, C; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nicholson, C; Nikolaev, I B; Ning, Z; Olsen, S L; Ouyang, Q; Pacetti, S; Park, J W; Pelizaeus, M; Peng, H P; Peters, K; Ping, J L; Ping, R G; Poling, R; Prencipe, E; Qi, M; Qian, S; Qiao, C F; Qin, X S; Qin, Y; Qin, Z H; Qiu, J F; Rashid, K H; Rong, G; Ruan, X D; Sarantsev, A; Schaefer, B D; Schulze, J; Shao, M; Shen, C P; Shen, X Y; Sheng, H Y; Shepherd, M R; Song, X Y; Spataro, S; Spruck, B; Sun, D H; Sun, G X; Sun, J F; Sun, S S; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Toth, D; Ullrich, M; Varner, G S; Wang, B; Wang, B Q; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Q; Wang, Q J; Wang, S G; Wang, X L; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z Y; Wei, D H; Weidenkaff, P; Wen, Q G; Wen, S P; Werner, M; Wiedner, U; Wu, L H; Wu, N; Wu, S X; Wu, W; Wu, Z; Xia, L G; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, G M; Xu, H; Xu, Q J; Xu, X P; Xu, Z R; Xue, F; Xue, Z; Yan, L; Yan, W B; Yan, Y H; Yang, H X; Yang, Y; Yang, Y X; Ye, H; Ye, M; Ye, M H; Yu, B X; Yu, C X; Yu, J S; Yu, S P; Yuan, C Z; Yuan, Y; Zafar, A A; Zallo, A; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, S H; Zhang, X J; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Y S; Zhang, Z P; Zhang, Z Y; Zhao, G; Zhao, H S; Zhao, J W; Zhao, K X; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, S J; Zhao, T C; Zhao, X H; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, Y H; Zhong, B; Zhong, J; Zhou, L; Zhou, X K; Zhou, X R; Zhu, C; Zhu, K; Zhu, K J; Zhu, S H; Zhu, X L; Zhu, X W; Zhu, Y C; Zhu, Y M; Zhu, Y S; Zhu, Z A; Zhuang, J; Zou, B S; Zou, J H

    2012-01-01

    The decay of $J/\\psi$ to three photons is studied using $\\psi^\\prime\\to\\pi^+\\pi^-J/\\psi$ in a sample of 106 million $\\psi^\\prime$ events collected with the BESIII detector. First evidence of the decay $\\eta_c\\to\\gamma\\gamma$ is reported, and the product branching fraction is determined to be $\\br{J/\\psi\\to\\gamma\\eta_c,\\eta_c\\to \\gamma\\gamma}=(4.5\\pm1.2\\pm0.6)\\times10^{-6}$, where the first error is statistical and the second systematic. The branching ratio for the direct decay is $\\br{J/\\psi\\to3\\gamma} = (11.3\\pm1.8\\pm2.0)\\times 10^{-6}$.

  12. The close-range gamma-graphy control - {gamma}-prox; Le controle par gammagraphie de proximite - {gamma}-prox

    Energy Technology Data Exchange (ETDEWEB)

    Blettner, A. [Institut de Soudure, 93 - Villepinte (France)

    2011-01-15

    This work deals with the {gamma}-prox: a modular device for proximity gamma-graphy. The dose rates obtained between the standard collimator and the {gamma}-prox are compared. A study, among the tools developed by the Welding Institute Industry, to estimate the occupational dosimetry is presented in order to determine the dose limits for a welding control of 255 mm diameter and 5 mm thickness, as well as the calculation of the signalling distances. (O.M.)

  13. Repatriation of Gamma Chambers Exported by India

    International Nuclear Information System (INIS)

    The Board of Radiation and Isotope Technology (BRIT) is engaged in the production and supply of laboratory gamma chambers. The gamma chambers are self-shielded devices in which a number of 60Co source pencils placed in a cylindrical cage. The gamma chambers are type approved as a device and a transportation package separately by the Atomic Energy Regulatory Board. BRIT has exported number of such gamma chambers. For some of the gamma chambers, the type approval validity period is over and can no longer be transported. Hence, the radiation sources need to be transferred to a type approved package before transportation. BRIT has decommissioned five such gamma chambers so far and sources have been repatriated back to India. (author)

  14. The topological filtration of $\\gamma$-structures

    CERN Document Server

    Li, Thomas J X

    2012-01-01

    In this paper we study $\\gamma$-structures filtered by topological genus. $\\gamma$-structures are a class of RNA pseudoknot structures that plays a key role in the context of polynomial time folding of RNA pseudoknot structures. A $\\gamma$-structure is composed by specific building blocks, that have topological genus less than or equal to $\\gamma$, where composition means concatenation and nesting of such blocks. Our main results are the derivation of a new bivariate generating function for $\\gamma$-structures via symbolic methods, the singularity analysis of the solutions and a central limit theorem for the distribution of topological genus in $\\gamma$-structures of given length. In our derivation specific bivariate polynomials play a central role. Their coefficients count particular motifs of fixed topological genus and they are of relevance in the context of genus recursion and novel folding algorithms.

  15. Recommended standards for gamma ray intensities

    Energy Technology Data Exchange (ETDEWEB)

    Bé, Marie-Martine, E-mail: mmbe@cea.fr [LNHB, CEA LIST Saclay, 91191 Gif-sur-Yvette Cedex (France); Chechev, Valery P. [KRI, V.G. Khlopin Radium Institute, St. Petersburg 194021 (Russian Federation)

    2013-11-11

    Gamma ray data are used in more and more areas of application, and so over the years the demand for recommended gamma ray energies and intensities has increased. This paper proposes a list of gamma rays whose intensity is sufficiently well-known and they can be used for the calibration of gamma ray spectrometers and other applications; it is based on studies carried out by an international group of evaluators: the Decay Data Evaluation Project. One goal of this paper is to gather this set of data together in order to facilitate and generalize their use. In the first part, a brief description of the methodology followed throughout the evaluations is given, different methods of gamma ray intensity evaluation are presented, some typical examples of evaluations are shown; in the second part, the list of chosen nuclides is given along with their applications, and finally a list of recommended gamma ray intensities is presented.

  16. Gamma-ray burst polarimeter (GAP)

    International Nuclear Information System (INIS)

    The gamma-ray burst polarimeter (GAP: GAmma-ray burst Polarimeter), which had been almost handcrafted by scientists, has succeeded in working normally in interplanetary space, and in detecting the polarization of the gamma-ray from a mysterious astronomical object 'gamma-ray burst'. It is the first result of the detectors in the world exclusively aiming at detecting gamma-ray polarization. We mainly describe the hardware of our GAP equipment and show the method of preparing equipment to work in the cosmic space with a tight budget. The mechanical structure, the electronic circuits, the software on the equipment, the data analysis on the earth, and the scientific results gained by the observation just over one year, are presented after explaining the principle of gamma-ray polarization detection. Our design to protect equipment against mechanical shock and cosmic radiation may provide useful information for future preparation of compact satellite. (J.P.N.)

  17. Human Gamma Oscillations during Slow Wave Sleep

    OpenAIRE

    Mario Valderrama; Benoît Crépon; Vicente Botella-Soler; Jacques Martinerie; Dominique Hasboun; Catalina Alvarado-Rojas; Michel Baulac; Claude Adam; Vincent Navarro; Michel Le Van Quyen

    2012-01-01

    Neocortical local field potentials have shown that gamma oscillations occur spontaneously during slow-wave sleep (SWS). At the macroscopic EEG level in the human brain, no evidences were reported so far. In this study, by using simultaneous scalp and intracranial EEG recordings in 20 epileptic subjects, we examined gamma oscillations in cerebral cortex during SWS. We report that gamma oscillations in low (30-50 Hz) and high (60-120 Hz) frequency bands recurrently emerged in all investigated r...

  18. Mining Gamma-Ray Burst Data

    OpenAIRE

    Hakkila, Jon; Roiger, Richard J.; Haglin, David J.; Mallozzi, Robert S.; Pendleton, Geoffrey N.; Meegan, Charles A.

    2000-01-01

    Gamma-ray bursts provide what is probably one of the messiest of all astrophysical data sets. Burst class properties are indistinct, as overlapping characteristics of individual bursts are convolved with effects of instrumental and sampling biases. Despite these complexities, data mining techniques have allowed new insights to be made about gamma-ray burst data. We demonstrate how data mining techniques have simultaneously allowed us to learn about gamma-ray burst detectors and data collectio...

  19. Gamma-Ray Astronomy Technology Needs

    Science.gov (United States)

    Gehrels, N.; Cannizzo, J. K.

    2012-01-01

    In recent decades gamma-ray observations have become a valuable tool for studying the universe. Progress made in diverse 8re1lS such as gamma-ray bursts (GRBs), nucleosynthesis, and active galactic nuclei (AGNs) has complimented and enriched our astrophysical understanding in many ways. We present an overview of current and future planned space y-ray missions and discussion technology needs for- the next generation of space gamma-ray instruments.

  20. The gamma knife: Dose and risk evaluation

    International Nuclear Information System (INIS)

    This paper outlines a risk analysis approach designed to identify and assess most likely failure modes and high-risk, human initiated actions for nuclear medical devices. This approach is being developed under the auspices of the US Nuclear Regulatory Commission, Office of Nuclear Material Safety and Safeguards. The methodology is initiated intended to assess risk associated with the use of the Leksell Gamma Unit (LGU) or gamma knife, a gamma stereotactic radiosurgical device

  1. Technology and use of gamma thermometers

    International Nuclear Information System (INIS)

    For several years, gamma thermometer rods bearing several sensors have been installed experimentally in some French reactors. Their purpose is to supplement present fission chambers. The signals delivered by the gamma thermometers indicate the power supplied locally by the fuel. Eight gamma thermometer rods installed at the CRUAS-2 power station are presently subject to regular readings and computations (sensitivity, response time) which indicate the existence of drift phenomena and parasitic noises which are presently under study

  2. TESLA*HERA Based gamma-p and gamma-A Colliders

    OpenAIRE

    Ciftci, A. K.; Sultansoy, S.; Yavas, O.

    2000-01-01

    Main parameters and physics search potential of gamma-p and gamma-A colliders, which will be available due to constructing the TESLA linear electron-positron collider tangentially to the HERA proton ring, are discussed.

  3. DELTA - a computer program to analyze gamma-gamma angular correlations from unaligned states

    International Nuclear Information System (INIS)

    A computer program to analyze gamma-gamma angular correlations from radioactive decay and from thermal-neutron capture is described. The program can, in addition to correlation data, handle mixing ratio and conversion coefficient data. (author)

  4. Using gamma-gamma coincidence measurements to validate Monte Carlo generated detector response functions

    International Nuclear Information System (INIS)

    Monte Carlo simulation of gamma-ray transport for the purpose of performing elemental analysis of bulk samples requires the tracking of gamma rays in the sample and also in the detector(s) used. Detector response functions (DRF's) are an efficient and accurate variance reduction technique that greatly decreases the simulation time by substituting the tracking of gamma rays inside the detector by predefined single energy gamma-ray spectra. These spectra correspond to the average response of the detector for incident gamma rays. DRF's are generated by Monte Carlo methods and are benchmarked with experimental data. In this work, prompt gamma-gamma coincidence measurements are presented as a way to validate DRF's for high-energy gamma rays

  5. Decision about buying a gamma camera

    International Nuclear Information System (INIS)

    A large part of the referral to a nuclear medicine department is usually for imaging studies. Sooner or later, the nuclear medicine specialist will be called upon to make a decision about when and what type of gamma camera to buy. There is no longer an option of choosing between a rectilinear scanner and a gamma camera as the former is virtually out of the market. The decision that one has to make is when to invest in a gamma camera, and then on what basis to select the gamma camera

  6. Multiple elliptic gamma functions associated to cones

    CERN Document Server

    Winding, Jacob

    2016-01-01

    We define generalizations of the multiple elliptic gamma functions and the multiple sine functions, associated to good rational cones. We explain how good cones are related to collections of $SL_r(\\mathbb{Z})$-elements and prove that the generalized multiple sine and multiple elliptic gamma functions enjoy infinite product representations and modular properties determined by the cone. This generalizes the modular properties of the elliptic gamma function studied by Felder and Varchenko, and the results about the usual multiple sine and elliptic gamma functions found by Narukawa.

  7. Natural gamma radiation borehole logging system

    International Nuclear Information System (INIS)

    A borehole logging system employs a gamma-ray detector for measuring the natural gamma radiation of the earth formations surrounding a borehole. Three energy band selectors, each employing a discriminator and count rate meter, separate the output of the gamma-ray detector into potassium, uranium, and thorium energy band signals. A first operational amplifier determines the difference between the potassium energy band signal and those portions of the uranium and thorium energy band signals which represent the influence of uranium and thorium gamma radiation within the potassium energy band, this difference representing the correct potassium gamma radiation. A second operational amplifier determines the difference between the uranium energy band signal and that portion of the thorium energy band signal which represents the influence of the thorium gamma radiation within the uranium energy band, this difference representing the correct uranium gamma radiation. A third operational amplifier determines the difference between the thorium energy band signal and that portion of the uranium energy band signal which represents the influence of the uranium gamma radiation within the thorium energy band, this difference representing the correct thorium gamma radiation

  8. Gamma radiography and its technological application

    International Nuclear Information System (INIS)

    After the presentation of gamma radiography and X-ray radiography, the author compare both techniques showing, in particular, the greater utility of gamma radiography in industrial diagnostic and more particularly on works site diagnostic. Problem of using radiography and safety consideration will be studied. Figures shows two radiography equipment which have been designed for gamma radiography respecting the safety regulations required by the Radioisotope Inter-ministerial Commission. In the second part, different techniques and uses of gamma radiography are briefly described : xerography, neutron radiography, fluoroscopy and imaging amplifier, tomography, betatrons and linear accelerators. Cost analysis will discussed in conclusion. (M.P.)

  9. Gamma analysis for transuranic waste assay

    International Nuclear Information System (INIS)

    Passive gamma analysis is one of the key technologies for the identification of transuranic elements in waste material. The techniques use high purity germanium detectors for the detection of the gamma photons. The detected signals are then analyzed in multi-channel gamma spectrometers to determine the photon energies. These photon energies are generally unique to the nuclide that produced the gamma rays and can, therefore, be used as an identifier of the nuclides present. This report is a discussion of methods used to calibrate the measurement systems and for the analysis of the data. 3 tabs

  10. Radion production in gamma-electron collisions

    CERN Document Server

    Soa, D V; Thao, N H; Thuy, D T L; 10.1142/S021773231250126X

    2012-01-01

    We analyze the potential of Compact Linear Colliders based on the \\gamma-e collisions to search for the radion in the Randall-Sundrum model, where compactification radius of the extra dimension is stabilized by the radion, which is a scalar field lighter than the graviton Kaluza-Klein states. The radion production in the high energy \\gamma-e colliders with the polarization of the electron beams are calculated in detail. Numerical evaluation shows that if the radion mass is not too heavy with the mass order of GeV then the reaction can give observable cross section in future colliders at the high degree of polarization.

  11. Application of conventional laser technology to gamma-gamma colliders

    International Nuclear Information System (INIS)

    A future e-e+ (electron-positron) linear collider can be configured with perhaps minimal modification to serve as an γ-γ (gamma-gamma) or a e--γ collider. This is accomplished by Compton-backscattering low energy photons (from a laser source) off of the high-energy electron beams prior to the crossing of the electron beams. However, to be competitive with the e-e+ configuration, the luminosity cannot be compromised in the process. This requires that the laser source deliver a sufficient number of photons per pulse with a pulse format and rate matching that of the electron beams. As it turns out, this requires an average optical power of 5 to 15 kW from the laser which is beyond the current state of the art. In this paper, the authors address how to generate the required pulse format and how the high average power requirement can be met with conventional laser technology. They also address concerns about the survivability of mirrors located near the interaction point. Finally, they list a program of research and development which addresses some of the unknowns in such a system

  12. Roy-Steiner equations for gamma gamma -> pi pi

    CERN Document Server

    Hoferichter, Martin; Schat, Carlos

    2011-01-01

    Starting from hyperbolic dispersion relations, we derive a system of Roy--Steiner equations for pion Compton scattering that respects analyticity, unitarity, gauge invariance, and crossing symmetry. It thus maintains all symmetries of the underlying quantum field theory. To suppress the dependence of observables on high-energy input, we also consider once- and twice-subtracted versions of the equations, and identify the subtraction constants with dipole and quadrupole pion polarizabilities. Based on the assumption of Mandelstam analyticity, we determine the kinematic range in which the equations are valid. As an application, we consider the resolution of the $\\gamma\\gamma\\to\\pi\\pi$ partial waves by a Muskhelishvili--Omn\\`es representation with finite matching point. We find a sum rule for the isospin-two $S$-wave, which, together with chiral constraints, produces an improved prediction for the charged-pion quadrupole polarizability $(\\alpha_2-\\beta_2)^{\\pi^\\pm}=(15.3\\pm 3.7)\\cdot 10^{-4} {\\rm fm}^5$. We inves...

  13. Skyshine spectra of gamma rays

    International Nuclear Information System (INIS)

    A study of the spectra of gamma photons back-scattered in vertical direction by infinite air above ground (skyshine) is presented. The source for these measurements is a 650 Ci Cobalt-60 point-source and the skyshine spectra are reported for distances from 150 m to 325 m from the source, measured with a 5 cm x 5 cm NaI(Tl) detector collimated with collimators of 12 mm and 20 mm diameter and 5 cm length. These continuous spectra are unfolded with Gold's iterative technique. The photon-spectra so obtained have a distinct line at 72 keV due to multiply-scattered photons. This is an energy where photoelectric and Compton cross-sections for multiply-scattered photons balance each other. The intensity of the line(I) decreases exponentially with distance (d) from the source obeying a relation of the type I = Isub(o)esup(-μd) where μ is called as ''Multiply-Scatter Coefficient'', a constant of the medium which is air in these measurements. This relationship is explained in terms of a halo around the source comprising of multiply-scattered gamma photons, Isub(0) being the intensity of these scattered photons at the location of cobalt-source. A fraction called as ''Back-scattered Fraction'', the ratio of Isub(0) to the number of original photons from the cobalt-source entering the infinite air, is also calculated. It is shown that with a properly calibrated detector system, this fraction can be used to determine the strength of a large gamma source, viz. a nuclear explosion in air, and for mineral prospecting. These conclusions are general and can be applied to any other infinite medium. Some forward-scatter (transmission) spectra of cobalt-60 source through 10 cm of Pb and 2.5 cm of Al are also reported. (auth.)

  14. Variance gamma process simulation and it's parameters estimation

    OpenAIRE

    Kuzmina, A. V.

    2010-01-01

    Variance gamma process is a three parameter process. Variance gamma process is simulated as a gamma time-change Brownian motion and as a difference of two independent gamma processes. Estimations of simulated variance gamma process parameters are presented in this paper.

  15. Sterilization plants equipped with the isotopic gamma radiation sources

    International Nuclear Information System (INIS)

    Presentation describes different isotopic gamma radiation sources applicable for sterilization of food and medical materials. Certain gamma pallet irradiators, mini gamma irradiators and different scale gamma tote irradiators are presented. It is concluded, that about two hundreds plants with gamma radiation sources operates in different countries. However, industrially developed countries must construct much more plants than operates now

  16. Gamma-Glutamyl Compounds: Substrate Specificity of Gamma-Glutamyl Transpeptidase Enzymes

    OpenAIRE

    Wickham, Stephanie; West, Matthew B.; Cook, Paul F.; Hanigan, Marie H.

    2011-01-01

    Gamma-glutamyl compounds include antioxidants, inflammatory molecules, drug metabolites and neuroactive compounds. Two cell surface enzymes have been identified that metabolize gamma-glutamyl compounds, gamma-glutamyl transpeptidase (GGT1) and gamma-glutamyl leukotrienase (GGT5). There is controversy in the literature regarding the substrate specificity of these enzymes. To address this issue, we have developed a method for comprehensive kinetics analysis of compounds as substrates for GGT en...

  17. Search for the decay $K_S \\to \\pi^0\\gamma\\gamma$

    OpenAIRE

    Lai, A.

    2002-01-01

    A search for the decay $K_S\\to\\pi^0\\gamma\\gamma$ has been made using the NA48 detector at the CERN SPS. Using data collected in 1999 during a 40-hour run with a high-intensity $K_S$ beam, an upper limit for the branching ratio $BR(K_S\\to\\pi^0\\gamma\\gamma, z\\ge 0.2)

  18. Gamma dosimetry of high doses

    International Nuclear Information System (INIS)

    The gamma dosimetry of high doses is problematic in almost all the classic dosemeters either based on the thermoluminescence, electric, chemical properties, etc., because they are saturated to very high dose and they are no longer useful. This work carries out an investigation in the interval of high doses. The solid system of heptahydrate ferrous sulfate, can be used as solid dosemeter of routine for high doses of radiation. The proposed method is simple, cheap and it doesn't require sophisticated spectrophotometers or spectrometers but expensive and not common in some laboratories

  19. Gamma irradiation of natural dyes

    International Nuclear Information System (INIS)

    Dyes play an important role in textile industry. Synthetic dyes of various classes are normally used for dyeing fabrics. Recently, considerable attention is focussed on the use of natural dyes all over the world in the context of German ban on some of synthetic azo dye due to their allergenic or carcinogenic potential. However natural dyes and their solution in aqueous medium show microbial contamination on storage. The present study deals with effect of gamma radiation on the microbial load, tinctorial value and dye uptake of natural dyes. (author)

  20. General introduction to gamma measurement

    International Nuclear Information System (INIS)

    The use of process instrumentation in industry is growing rapidly. As our work force is being down sized in favor of more distributed and computer controlled systems, the need for reliable process measurement is increasing. With this growth, the use of nuclear gauges is also increasing. The nuclear instrumentation field covers a broad spectrum which would require several papers to do it justice. In order to utilize the space allotted to best advantage, this paper will center around gamma gauges and their application to level, density, mass-flow and weight measurement

  1. Measurement and analysis of the reaction. gamma. gamma. ->3. pi. sup + 3. pi. sup -

    Energy Technology Data Exchange (ETDEWEB)

    Pust, R.; Greenshaw, T.; Hagemann, J.; Heinzelmann, G.; Kleinwort, C.; Kuhlen, M.; Naroska, B.; Ould-Saada, F.; Pitzl, D.; Schneekloth, U.; Weber, G. (Hamburg Univ. (Germany, F.R.). 2. Inst. fuer Experimentalphysik); Olsson, J.; Bartel, W.; Felst, R.; Haidt, D.; Kado, H.; Knies, G.; Krehbiel, H.; Magnussen, N.; Meinke, R.; Ramcke, R.; Schmidt, D.; Steffen, P. (Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany, F.R.)); Allison, J.; Barlow, R.J.; Chrin, J.; Duerdoth, I.P.; Loebinger, F.K.; Macbeth, A.A.; Murphy, P.G.; Stephens, K. (Manchester Univ. (UK)); Ambrus, K.; Bethke, S.; Dieckmann, A.; Eckerlin, G.; Elsen, E.; Heintze, J.; Hellenbrand, K.H.; Komamiya, S.; Krogh, J. v.; Rieseberg, H.; Smolik, L.; Spitzer, J.; Wagner, A.; Zimmer, M. (Heidelberg Univ. (Germany, F.R.). Physikalisches Inst.); Bowdery, C.K.; Finch, A.J.; Foster, F.; Hughes, G.; Nye, J.M.; Walker, I.W. (Lancaster Univ. (UK)); Cartwright, S.L.; Clarke, D.; Marshall, R.; Middleton, R.P. (Rutherford Appleton L; JADE Collaboration

    1991-08-01

    The reaction {gamma}{gamma}->3{pi}{sup +}3{pi}{sup -} has been studied using the JADE detector at PETRA. The topological cross section {sigma} ({gamma}{gamma}->3{pi}{sup +}3{pi}{sup -}) was measured in the CM energy range 1.5-5.5 GeV. The production of rho{sup 0}'s was observed and the average number of rho{sup 0}'s per event measured. The contributions of the subprocesses {gamma}{gamma}->rho{sup 0}2{pi}{sup +}2{pi}{sup -}, {gamma}{gamma}->rho{sup 0}rho{sup 0}{pi}{sup +}{pi}{sup -} and {gamma}{gamma}->3{pi}{sup +}3{pi}{sup -} (phase space) were studied and 95% C.L. upper limits for the cross section {sigma}({gamma}{gamma}->rho{sup 0}rho{sup 0}{pi}{sup +}{pi}{sup -}) determined. Finally the Bose-Einstein correlation for pairs of like signed pions was observed. A fit to a standard parametrization gave results consistent with other studies of this effect in pion systems. (orig.).

  2. Gravitational Waves versus X and Gamma Ray Emission in a Short Gamma-Ray Burst

    OpenAIRE

    Oliveira, F. G.; Rueda, Jorge A.; Ruffini, Remo

    2012-01-01

    The recent progress in the understanding the physical nature of neutron star equilibrium configurations and the first observational evidence of a genuinely short gamma-ray burst, GRB 090227B, allows to give an estimate of the gravitational waves versus the X and Gamma-ray emission in a short gamma-ray burst.

  3. Food irradiation: Gamma processing facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kunstadt, P. [MDS Nordion International, 447 March Road. Kanata, Ontario, K2K148 (Canada)

    1997-12-31

    The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

  4. Gamma Irradiation of Polyesters Film

    International Nuclear Information System (INIS)

    Experimental investigations on the effects of gamma irradiation in air of aromatic polyesters are carried out, in order to evaluate the influence of aromatic density and the role of oxygen on the radiation resistance. The thermoplastic polyesters PolyEthyleneTerephthalate (PET), PolyButylene Terephthalate (PBT), PolyEthyleneNaphthalate (PEN), Poly1,4-cyclohexanedimethylen terephthalate-co-ethyleneterephthalate (PCT-co-ET) are moulded in thin films of 50 micron and irradiated at different absorbed doses, ranging from 0 to 1000 kGy, using a Co-60 gamma source. The structural changes in the polymers are studied by means of several physical-chemical and nuclear techniques. Electron Paramagnetic Resonance analyses are carried out to detect the radicals induced by irradiation and to follow their decay by oxygen permeation. Viscometric measurements show a similar trend for the different irradiated polyesters: in particular, chain scission induced by irradiation depends on the aromatic density contained in the polymer and shows a saturation effect at the highest doses. Positron Annihilation Lifetime Spectroscopy points out a decrease of the ortho-positronium signal caused by the production of oxidized species inhibiting the positronium formation. Finally, the experimental results obtained on the irradiated films are compared with previous studies carried out on the same polyesters moulded in sheets of 1-2 mm of thickness and γ-irradiated at the same adsorbed doses

  5. Gamma-irradiation of tomatoes

    International Nuclear Information System (INIS)

    The influence of gamma-ray on tomatoes picked in a pink-red ripening stage, good for consumption, is studied. For that purpose tomatoes of ''Pioneer 2'' variety packed in perforated 500 g plastic bags were irradiated on a gamma device (Cobalt-60) at a dose power of 1900 rad/min with doses 200 or 300 krad. Samples were stored after irradiation at room temperature (20 - 22sup(o)C). Microbiological studies demonstrated that 44 resp. 99.96 per cent of the initial number of microorganisms was destroyed after irradiation with 200 resp. 300 krad. The time required for the number of microorganisms to be restored was accordingly increased. Irradiation delayed tomato ripening by 4 to 6 days, demonstrable by the reduced content of the basic staining substances - carotene and licopine. Immediately after irradiation the ascorbic acid content was reduced by an average of 13 per cent. After 18 days the amount of ascorbic acid in irradiated tomatoes was increased to a higher than the starting level, this is attributed to reductone formation during irradiation. The elevated total sugar content shown to be invert sugar was due to further tomato ripening. (Ch.K.)

  6. Food irradiation: Gamma processing facilities

    International Nuclear Information System (INIS)

    The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

  7. Gamma scale chemistry progress report

    Energy Technology Data Exchange (ETDEWEB)

    Economides, M.; Estabrook, E.; Joy, E.F. [and others

    1948-06-01

    This report considers the work done during the year ending June 30, 1948, present work being done and future plans on the determination of formulas, methods of preparation, and properties of as many compounds of postum as possible. An experimental approach to such a research problem on the element postum requires that procedures which may be used deal with ultramicro quantities of material. Such procedures on an ultramicro or gamma scale require special techniques by personnel trained in manipulating these small quantities of radioactive material. Equipment which may be used varies with the experiment considered. Often new apparatus must be developed or equipment previously developed and used in some other experiment must be modified. This generalized research problem is subdivided in the {open_quotes}Research Problems Outline{close_quotes}. The presentation of a survey of these research problems with reference to the outline for the year ending June 30, 1948 is a critical review of the work done by the Gamma Scale Chemistry Group as well as a consideration of future plans. The course which these future plans may follow will depend upon information which may be obtained when carrying out planned experiments.

  8. Gemstone dedicated gamma irradiation development

    International Nuclear Information System (INIS)

    The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to its poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator constructed in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations, were performed. With the definitive optimized irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. This work presents some optimization parameters and the expected performance of the irradiator. (author)

  9. Gemstone dedicated gamma irradiation development

    Energy Technology Data Exchange (ETDEWEB)

    Omi, Nelson M.; Rela, Paulo R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: nminoru@ipen.br; prela@ipen.br

    2007-07-01

    The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to its poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator constructed in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations, were performed. With the definitive optimized irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. This work presents some optimization parameters and the expected performance of the irradiator. (author)

  10. Photon structure functions and azimuthal correlations of lepton pairs in tagged $\\gamma\\gamma$ collisions

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banerjee, Sw; Banicz, K; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Braccini, S; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chekanov, S V; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Easo, S; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Lacentre, P E; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lavorato, A; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Marchesini, P A; Marian, G; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; Mazumdar, K; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Migani, D; Mihul, A; Van Mil, A J W; Milcent, H; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Moulik, T; Mount, R; Muheim, F; Muijs, A J M; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Nowak, H; Oh, Yu D; Organtini, G; Ostonen, R; Palit, S; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Produit, N; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Raja, N; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Rind, O; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Vlachos, S; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, A; Ziegler, F; Zilizi, G

    1998-01-01

    Measurements of the QED structure of the photon based on the reaction ee to ee gamma /sup (*)/(P/sup 2/) gamma *(Q/sup 2/) to ee mu mu are discussed. This review is an update of the discussion of the results on the QED structure of the photon and covers the published measurements of the photon structure functions F/sub 2//sup gamma /, F/sub A//sup gamma / and F/sub B//sup gamma / and of the differential cross-section d sigma /dx for the exchange of two virtual photons. (10 refs).

  11. Games with gammas: problems in environmental gamma dose determination

    International Nuclear Information System (INIS)

    The evaluation of the environmental dose rate is fundamental to ESR, OTL and TL dating, but results from different measurement methods, independently calibrated, are not always consistent. Some field measurements of environmental dose rate using a Canberra field gamma spectrometer are compared with those obtained using TLD and show a systematic discrepancy close to a factor of two. Possible reasons for the discrepancy are discussed but none offers a sufficiently substantial adjustment to reconcile the disagreement in the results given by the two methods. Comparison with dose rates estimated from radionuclide concentrations could not determine which method was more accurate as the correlation between these estimates and the previous ones was negligible, casting some doubt on the accuracy of the concentration estimates. The danger of relying on a single method of estimating dose rate without careful cross-calibration is highlighted. (author)

  12. A 16N gamma-ray facility

    Science.gov (United States)

    Hull, Ethan L.; Pehl, Richard H.; Stanley, Michelle R.; Foster, Charles C.; Komisarcik, Kevin; East, Gary W.; Vanderwerp, John D.; Friesel, Dennis L.

    1997-02-01

    A practical 16N gamma-ray source is created in a medium-energy cyclotron environment. A 16N source emits 6129 and 7115 keV gamma rays. The viability of this several μCi source for detector calibration and studying detector physics is established.

  13. A 16N gamma-ray facility

    International Nuclear Information System (INIS)

    A practical 16N gamma-ray source is created in a medium-energy cyclotron environment. A 16N source emits 6129 and 7115 keV gamma rays. The viability of this several μCi source for detector calibration and studying detector physics is established. (orig.)

  14. Automation of scanning technique by gamma radiation

    International Nuclear Information System (INIS)

    The gamma scan technique is a nuclear test allowing the analysis of the internal mechanical properties of distillation columns used in petrochemical industries. Such technique is performed manually. So we propose in this work to automate the gamma scan procedure test by using a PLC. In addition, supervision and data acquisition interfaces are proposed.

  15. Airborne Gamma-Ray Survey RISØ 2004

    DEFF Research Database (Denmark)

    Aage, Helle Karina

    The aim of the described survey was to monitor the gamma radiation originating from the waste disposal deposits and the now closed reactor.......The aim of the described survey was to monitor the gamma radiation originating from the waste disposal deposits and the now closed reactor....

  16. Intercomparison of gamma ray analysis software packages

    International Nuclear Information System (INIS)

    The IAEA undertook an intercomparison exercise to review available software for gamma ray spectra analysis. This document describes the methods used in the intercomparison exercise, characterizes the software packages reviewed and presents the results obtained. Only direct results are given without any recommendation for a particular software or method for gamma ray spectra analysis

  17. A gamma model for {DNA} mixture analyses

    OpenAIRE

    Cowell, R. G.; Lauritzen, S L; Mortera, J.

    2007-01-01

    We present a new methodology for analysing forensic identification problems involving DNA mixture traces where several individuals may have contributed to the trace. The model used for identification and separation of DNA mixtures is based on a gamma distribution for peak area values. In this paper we illustrate the gamma model and apply it on several real examples from forensic casework.

  18. SPACE: More high energy gamma sources

    International Nuclear Information System (INIS)

    Ultra high energy (TeV) gamma rays have been observed by an international team working at the Whipple observatory in Arizona. These also correlate with some of the signals seen by NASA's big Gamma Ray Observatory (GRO) satellite launched by the Space Shuttle Atlantis last year

  19. Handbook on Mobile Gamma-ray Spectrometry

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C

    2003-01-01

    Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing......Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing...

  20. High-Energy Gamma and Neutrino Astronomy

    OpenAIRE

    Bergstrom, L.

    1997-01-01

    An overview is given of high-energy gamma-ray and neutrino astronomy, emphasizing the links between the two fields. With several new large detectors just becoming operational, the TeV gamma-ray and neutrino sky will soon be surveyed with unprecedented sensitivity.

  1. The topological filtration of gamma-structures

    DEFF Research Database (Denmark)

    Li, T. J.; Reidys, C. M.

    2013-01-01

    topological genus less than or equal to gamma, where composition means concatenation and nesting of such blocks. Our main results are the derivation of a new bivariate generating function for gamma-structures via symbolic methods, the singularity analysis of the solutions and a central limit theorem for the...

  2. [Gamma glutamly transpeptidase in chronic anicteric hepatopathies].

    Science.gov (United States)

    Magris, D; Mian, G; Minutillo, S; D'Agnolo, B

    1975-09-01

    Serum levels of gammaGT were determined in 51 patients suffering from bioptically verified chronic anictereric liber disease. GammaGT proved to be much more sensitive than the other enzymes studied and presented a significant increase particularly in cases of steatosis and chronic "alcoholic" liver disease with a markedly steatosic character. PMID:241034

  3. Gamma spectrometric assessment of nuclear fuel

    Science.gov (United States)

    Krištof, Edvard; Pregl, Gvido

    1990-12-01

    A description is given of a gamma spectrometric technique which has been developed with the aim of determining the amount of a certain radioactive fission product taking into consideration local variations of the linear attenuation coefficient of gamma rays. Also, an experiment using a fuel element of the TRIGA Mark II reactor in Ljubljana is presented.

  4. Which multivariate gamma distributions are infinitely divisible?

    OpenAIRE

    Bernardoff, Philippe

    2006-01-01

    We define a multivariate gamma distribution on [math] by its Laplace transform [math] , [math] where ¶ [math] ¶ Under [math] , we establish necessary and sufficient conditions on the coefficients of [math] such that the above function is the Laplace transform of some probability distribution, for all [math] thus characterizing all infinitely divisible multivariate gamma distributions on [math

  5. Prompt gamma-ray activation analysis (PGAA)

    Energy Technology Data Exchange (ETDEWEB)

    Kern, J. [Fribourg Univ. (Switzerland). Inst. de Physique

    1996-11-01

    The paper deals with a brief description of the principles of prompt gamma-ray activation analysis (PGAA), with the detection of gamma-rays, the PGAA project at SINQ and with the expected performances. 8 figs., 3 tabs., 10 refs.

  6. The GAMMA-400 gamma-ray telescope characteristics. Angular resolution and electrons/protons separation

    CERN Document Server

    Leonov, A A; Bonvicini, V; Topchiev, N P; Adriani, O; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Bergstrom, L; Berti, E; Bigongiari, G; Bobkov, S G; Boezio, M; Bogomolov, E A; Bonechi, S; Bongi, M; Bottai, S; Boyarchuk, K A; Castellini, G; Cattaneo, P W; Cumani, P; Dedenko, G L; De Donato, C; Dogiel, V A; Gorbunov, M S; Gusakov, Yu V; Hnatyk, B I; Kadilin, V V; Kaplin, V A; Kaplun, A A; Kheymits, M D; Korepanov, V E; Larsson, J; Loginov, V A; Longo, F; Maestro, P; Marrocchesi, P S; Mikhailov, V V; Mocchiutti, E; Moiseev, A A; Mori, N; Moskalenko, I V; Naumov, P Yu; Papini, P; Pearce, M; Picozza, P; Popov, A V; Rappoldi, A; Ricciarini, S; Runtso, M F; Ryde, F; Serdin, O V; Sparvoli, R; Spillantini, P; Suchkov, S I; Tavani, M; Taraskin, A A; Tiberio, A; Tyurin, E M; Ulanov, M V; Vacchi, A; Vannuccini, E; Vasilyev, G I; Yurkin, Yu T; Zampa, N; Zirakashvili, V N; Zverev, V G

    2014-01-01

    The measurements of gamma-ray fluxes and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV, which will be implemented by the specially designed GAMMA-400 gamma-ray telescope, concern with the following broad range of science topics. Searching for signatures of dark matter, surveying the celestial sphere in order to study gamma-ray point and extended sources, measuring the energy spectra of Galactic and extragalactic diffuse gamma-ray emission, studying gamma-ray bursts and gamma-ray emission from the Sun, as well as high precision measuring spectra of high-energy electrons and positrons, protons and nuclei up to the knee. To clarify these scientific problems with the new experimental data the GAMMA-400 gamma-ray telescope possesses unique physical characteristics comparing with previous and present experiments. For gamma-ray energies more than 100 GeV GAMMA-400 provides the energy resolution of ~1% and angular resolution better than 0.02 deg. The methods developed to reconstru...

  7. Software tool for xenon gamma-ray spectrometer control

    Science.gov (United States)

    Chernysheva, I. V.; Novikov, A. S.; Shustov, A. E.; Dmitrenko, V. V.; Pyae Nyein, Sone; Petrenko, D.; Ulin, S. E.; Uteshev, Z. M.; Vlasik, K. F.

    2016-02-01

    Software tool "Acquisition and processing of gamma-ray spectra" for xenon gamma-ray spectrometers control was developed. It supports the multi-windows interface. Software tool has the possibilities for acquisition of gamma-ray spectra from xenon gamma-ray detector via USB or RS-485 interfaces, directly or via TCP-IP protocol, energy calibration of gamma-ray spectra, saving gamma-ray spectra on a disk.

  8. Reaction Rate Sensitivity of the gamma-Process Path

    OpenAIRE

    Rauscher, T.

    2004-01-01

    The location of the (gamma,p)/(gamma,n) and (gamma,alpha)/(gamma,n) line at gamma-process temperatures is discussed, using recently published reaction rates based on global Hauser-Feshbach calculations. The results can directly be compared to previously published, classic gamma-process discussions. The nuclei exhibiting the largest sensitivity to uncertainties in nuclear structure and reaction parameters are specified.

  9. Fabrication of gamma sources using the neutron-gamma reactions of 238Pu13C

    International Nuclear Information System (INIS)

    A production campaign for 238Pu13C sources with gamma fluence ranging from 2500 to 4500 gamma/s/4π at 6.13 MeV was carried out in 2002 in Atalante. An experimental study was undertaken to prepare the 238PuC mixture, which is the most delicate step. This procedure is described together with the other steps in the source fabrication process: purification of a plutonium oxide batch, preparation of a nitric solution of 238Pu, measurement of the gamma fluence of the PuC mixture before and after insertion into each of the two stainless steel capsules that constitute a PuN2O package, welding of the second envelope followed by leak testing, final measurement of the gamma fluence of the sealed source. This PuC sources fabrication procedure is effective: all the sources include the required gamma activity with an uncertainty on the gamma fluence of less than 10%. (authors)

  10. The absorption of gamma, gamma-families and hadrons in the atmosphere - EC data

    Energy Technology Data Exchange (ETDEWEB)

    Shaulov, S.B., E-mail: shaul@sci.lebedev.r [P.N.Lebedev physical Institute, FIAN, Leninsky prospect 53, 119991 Moscow (Russian Federation); Cherdyntceva, K.V. [P.N.Lebedev physical Institute, FIAN, Leninsky prospect 53, 119991 Moscow (Russian Federation); Janceitova, J.K. [Tien-Shan Highmountain Station, Mitina 3, Almaty (Kazakhstan)

    2009-12-15

    The energy spectra SIGMAE{sub g}amma, E{sub g}amma for gamma-families and hadrons at the level of the Pamir (600 g/cm{sup 2}) and Tien-Shan (685 g/cm{sup 2}) mountains are compared. The ratio of event intensities permits to observe the absorption lengths for different types of events in X-ray emulsion chambers: single gamma-quanta, hadrons, gamma-families and super-families with halo. These values of lambda{sub att} are much more than those determined from zenith angle distributions. Data from other EC experiments are used to decrease the errors in lambda{sub att}. The absorption curves in the atmosphere were obtained for gamma-families and gamma-quanta by means of data compiled for different EC experiments at balloon, aeroplane and mountain heights. The absorption curves cannot be described as a simple exponential dependence in both cases.

  11. Study of $\\psi(2S)$ decays into $\\gamma K^+K^-$ and $\\gamma \\pi^+\\pi^-$

    CERN Document Server

    Ablikim, M; Bai, J Z; Ban, Y; Cai, X; Chen, H F; Chen, H S; Chen, H X; Chen, J C; Chen, Jin; Chen, Y B; Chu, Y P; Dai, Y S; Diao, L Y; Deng, Z Y; Dong, Q F; Du, S X; Fang, J; Fang, S S; Fu, C D; Gao, C S; Gao, Y N; Gu, S D; Gu, Y T; Guo, Y N; Guo, Z J; Harris, F A; LHe, K; He, M; Heng, Y K; Hou, J; Hu, H M; Hu, J H; Hu, T; Huang, X T; Ji, X B; Jiang, X S; Jiang, X Y; Jiao, J B; Jin, D P; Jin, S; Lai, Y F; Li, G; Li, H B; Li, J; Li, R Y; Li, S M; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Liang, Y F; Liao, H B; Liu, B J; Liu, C X; Liu, F; Liu, Fang; Liu, H H; Liu, H M; Liu, J; Liu, J B; Liu, J P; Liu, Jian; Liu, Q; Liu, R G; Liu, Z A; Lou, Y C; Lu, F; Lu, G R; Lu, J G; Lundborg, A; Luo, C L; Ma, F C; Ma, H L; Ma, L L; Ma, Q M; Mao, Z P; Mo, X H; Nie, J; Olsen, S L; Ping, R G; Qi, N D; Qin, H; Qiu, J F; Ren, Z Y; Rong, G; Ruan, X D; Shan, L Y; Shang, L; Shen, C P; Shen, D L; Shen, X Y; Sheng, H Y; Sun, H S; Sun, S S; Sun, Y Z; Sun, Z J; Tang, X; Tong, G L; Varner, G S; Wang, D Y; Wang, L; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Y F; Wang, Z; Wang, Z Y; Wang, Zheng; Wei, C L; Wei, D H; Weng, Y; Wiedner, U; Wu, N; Xia, X M; Xie, X X; Xu, G F; Xu, X P; Xu, Y; Yan, M L; Yang, H X; Yang, Y X; Ye, M H; Ye, Y X; Yu, G W; Yuan, C Z; Yuan, Y; Zhang, S L; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C C; Zhang, D H; Zhang, H Q; Zhang, H Y; Zhang, J W; Zhang, J Y; Zhang, S H; Zhang, X Y; Zhang, Yiyun; Zhang, Z X; Zhang, Z P; Zhao, D X; Zhao, W J; Zhao, M G; Zhao, P P; Zhao, W R; Zhao, Z G; Zheng, H Q; Zheng, J P; Zheng, Z P; Zhou, L; Zhu, K J; Zhu, Q M; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, B A; Zhuang, X A; Zou, B S

    2007-01-01

    Radiative charmonium decays from the BESII sample of 14$\\times10^{6}$ $\\psi(2S)$-events into two different final states, $\\gamma K^+K^-$ and $\\gamma\\pi^+\\pi^-$, are analyzed. Product branching fractions for $\\psi(2S)\\to\\gamma X\\to \\gamma\\pi^+\\pi^-$, $\\gamma K^+K^-$ are given, where $X=f_2(1270)$, $f_0(1500)$, and $f_0(1710)$ in $\\pi^+\\pi^-$ and $f_2(1270)$, $f_2'(1525)$, and $f_0(1700)$ in $K^+K^-$. An angular analysis gives the ratios of the helicity projections for the $f_2(1270)$ in $\\psi(2S)\\to\\gamma f_2(1270)\\to\\gamma\\pi^+\\pi^-$.

  12. Gamma-ray pulsars: a gold mine

    CERN Document Server

    Grenier, Isabelle A

    2015-01-01

    The most energetic neutron stars, powered by their rotation, are capable of producing pulsed radiation from the radio up to gamma rays with nearly TeV energies. These pulsars are part of the universe of energetic and powerful particle accelerators, using their uniquely fast rotation and formidable magnetic fields to accelerate particles to ultra-relativistic speed. The extreme properties of these stars provide an excellent testing ground, beyond Earth experience, for nuclear, gravitational, and quantum-electrodynamical physics. A wealth of gamma-ray pulsars has recently been discovered with the Fermi Gamma-Ray Space Telescope. The energetic gamma rays enable us to probe the magnetospheres of neutron stars and particle acceleration in this exotic environment. We review the latest developments in this field, beginning with a brief overview of the properties and mysteries of rotation-powered pulsars, and then discussing gamma-ray observations and magnetospheric models in more detail.

  13. GEANT simulation of the $\\gamma$ nuclear gauge

    CERN Document Server

    Ouardi, A; Benchekroun, D; Hoummada, A

    2003-01-01

    The gamma nuclear gauging technique used for monitoring the sediment load suspended in water, is based on the detection of gamma rays emitted by a radioactive source. The GEANT321 Monte Carlo simulation tool, originally developed at CERN for high energy physics experiments, is used for the evaluation and calibration of gamma nuclear gauges. A set of parameters, principally the source energy, the source-detector separation, the lead block thickness and the energy threshold below which the sediments elemental composition affects the measurement or the energy corresponding to the Compton and photoelectric windows separation, are discussed and evaluated in the case of the gamma scattering gauge. For the gamma transmission gauge, the GEANT321 code has been used to define the optimal source detector distance interval, particularly for the Moroccan sediment samplers, and to check the influence of the radionuclide existing in the suspension, on the gauge response accuracy. Experimental calibration was also carried ou...

  14. Simultaneous beta/gamma digital spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.

    A state-of-the-art radiation detection system for simultaneous spectroscopy of beta-particles and gamma-rays has been developed. The system utilizes a triple-layer phoswich detector and a customized Digital Pulse Processor (DPP) built in our laboratory. The DPP board was designed to digitally capture the analog signal pulses and, following several digital preprocessing steps, transfer valid pulses to the host computer for further digital processing. A MATLAB algorithm was developed to digitally discriminate beta and gamma events and reconstruct separate beta and gamma-ray energy spectra with minimum crosstalk. The spectrometer proved to be an effective tool for recording separate beta and gamma-ray spectra from mixed radiation fields. The system as a beta-gamma spectrometer will have broad-ranging applications in nuclear non-proliferation, radioactive waste management, worker safety, systems reliability, dose assessment, and risk analysis.

  15. Librarian driven analysis of gamma ray spectra

    International Nuclear Information System (INIS)

    For a set of a priori given radionuclides extracted from a general nuclide data library, the authors use median estimates of the gamma-peak areas and estimates of their errors to produce a list of possible radionuclides matching gamma ray line(s). The identification of a given radionuclide is obtained by searching for a match with the energy information of a database. This procedure is performed in an interactive graphic mode by markers that superimpose, on the spectral data, the energy information and yields provided by a general gamma ray data library. This library of experimental data includes approximately 17,000 gamma ray energy lines related to 756 known gamma emitter radionuclides listed by the ICRP. (author)

  16. Unveiling the Secrets of Gamma Ray Bursts

    CERN Document Server

    Gomboc, A

    2012-01-01

    Gamma Ray Bursts (GRBs) are unpredictable and brief flashes of gamma rays that occur about once a day in random locations in the sky. Since gamma rays do not penetrate the Earth's atmosphere, they are detected by satellites, which automatically trigger ground-based telescopes for follow-up observations at longer wavelengths. In this introduction to Gamma Ray Bursts we review how building a multi-wavelength picture of these events has revealed that they are the most energetic explosions since the Big Bang and are connected with stellar deaths in other galaxies. However, in spite of exceptional observational and theoretical progress in the last 15 years, recent observations raise many questions which challenge our understanding of these elusive phenomena. Gamma Ray Bursts therefore remain one of the hottest topics in modern astrophysics.

  17. High Energy Radiation from $\\gamma$ Ray Bursts

    CERN Document Server

    Dermer, C D; Dermer, Charles D.; Chiang, James

    1999-01-01

    Gamma-ray burst (GRB) engines are probed most intimately during the prompt gamma-ray luminous phase when the expanding blast wave is closest to the explosion center. Using GRBs 990123 and 940217 as guides, we briefly review observations of high-energy emission from GRBs and summarize some problems in GRB physics. \\gamma\\gamma transparency arguments imply relativistic beaming. The parameters that go into the external shock model are stated, and we show numerical simulation results of gamma-ray light curves from relativistic blast waves with different amounts of baryon loading. A distinct component due to the synchrotron self-Compton process produces significant emission at GeV and TeV energies. Predictions for spectral and temporal evolution at these energies are presented for a blast wave expanding into uniform surroundings. Observations of the slow decay of GeV-TeV radiation provide evidence for ultra-high energy cosmic ray acceleration in GRBs.

  18. Production of modified starches by gamma irradiation

    International Nuclear Information System (INIS)

    As a new processing method for the production of modified starch, gamma irradiation and four kinds of inorganic peroxides were applied to commercial corn starch. The addition of inorganic peroxides without gamma irradiation or gamma irradiation without the addition of inorganic peroxides effectively decreased initial viscosity, but did not sufficiently keep viscosity stable. The combination of adding ammonium persulfate (APS) and gamma irradiation showed the lowest initial viscosity and the best stability out of the tested four kinds of inorganic peroxides. Among the tested mixing methods of APS, soaking was found to be more effective than dry blending or spraying. Therefore, the production of modified starch with low viscosity as well as with sufficient viscosity stability became feasible by the control of gamma irradiation dose levels and the amount of added APS to starch

  19. Stratospheric discharges during solar gamma flares

    CERN Document Server

    Moldavanov, A V

    2003-01-01

    It is known that specifics of angle distribution of recoiling electrons being generated at the Compton scattering process of the gamma quanta (electrons flight angles spectrum is [0,180 deg.]) creates favourable conditions for the production of after-collision electron flux along the original direction of the gamma quanta motion, which means that electric current is initiated. The weak values of the gamma ray fluxes from sources in space made difficult the geophysical applications of this concept. However, recent investigations have shown that taking into consideration the real variations of the energy spectrum of space gamma rays may increase significantly the impact of the weak stratosphere currents on the parameters of the global atmosphere-ionosphere electric circuit. Earlier, this theoretical model has been used as a possible basis of the direct driven mechanism of development of the large-scale geomagnetic oscillations during solar gamma flares. This paper emphasizes the storage-release aspect of the st...

  20. The effect of artificial boundary grain on the magneto- and electro-transport properties of (1 − x)La0.7Ca0.3MnO3+xA (A=Al2O3 and Ag) nanocomposite

    International Nuclear Information System (INIS)

    The magneto- and electro-transport properties of two series of nanocrystalline (1−x)La0.7Ca0.3MnO3+xA (A: Al2O3 and Ag) composites have been systematically and thoroughly studied. The observed electronic transport behavior over the whole temperature range (5–300 K), especially the change in metal–insulator transition temperature with increasing Al2O3 and Ag content while the ferromagnetic–paramagnetic transition remained unaffected, was explained by applying a two-component phenomenological model. We have attributed the unusual low-temperature resistivity upturn of composites to a change in charging energy. Most interestingly, magneto-transport measurements showed that the low-field magnetoresistance (LFMR), as well as the high-field magnetoresistance (HFMR), displayed a Curie–Weiss-like law behavior. Basing on the spin-polarized transport of conduction electrons at the grain boundaries, we have analyzed our experimental data and found that the temperature dependence of low- and high-field magnetoresistance is controlled predominantly by the nature of the temperature response of surface magnetization of particles. The competition between grain-boundary pinning strength (k), magnetic field and thermal energy (kBT) created the temperature sensitive behavior of magnetoresistance as well as that of surface spin susceptibility (χ b)

  1. Gamma sterilization of disposable medical products (DMP's)

    International Nuclear Information System (INIS)

    Ten million cubic meters (361 million cubic feet) of disposable medical products (DMP) and related health care items are estimated to be sterilized in the world. In this paper, current conditions and perspectives of gamma sterilization is discussed in comparison with ethylene oxide gas and electron beams. Of the total sterilization estimates for DMP, 2.8 million cubic meters (99 million cubic feet) are sterilized with gamma radiation, with a market share of 27%. Gamma radiation is becoming increased from both general market growth and the introduction of new products, as well as the conversion of product from ethylene oxide gas to cobalt-60. Regulatory pressures, legal considerations, and increasing publicity surrounding ethylene oxide usage are encouraging manufactures to switch to gamma radiation. Gamma's performance features include: no temperature change during the sterilization, high penetration, even through hermetically sealed packages, no residues, and no post-sterilization treatment or quarantine period. Gamma sterilization is economically beneficial in large volumes of product. Cost saving to the end user of gamma sterilization has meant lower minimum dose levels than 25 KGy. Despite of an increasingly accepted gamma radiation, there are still four factors to be considered, including cobalt-60 availability, price, transportation, and disposal. The price of cobalt-60 is based on neutron cost. In the future, cobalt-60 price is expected to be flat and enables gamma processing to become even more competitive with other sterilization methods. Gamma radiation using cobalt-60 has been proven as a safe, effective, and cost-competitive sterilization method for treating DMP and related health care items. It's wide use and many processing advantages will continue to make it a preferred sterilization method. (N.K.)

  2. The Portuguese gamma irradiation facility

    International Nuclear Information System (INIS)

    A Gamma Radiation Facility was built up in the National Laboratory of Industrial Technology and Engineering (LNETI), Lisbon, Portugal. This plant (UTR GAMA-Pi) is a Cobalt-60 dry storage continuous facility with a nominal capacity of 1.5 x 1016 Bq. The initial activity is 1.1 x 1016 Bq and the throughput capacity 103 ton/year for product with a bulk density of 0.2 g/cm3 treated with a minimum absorbed dose of 25 kGy. Complementary control devices were installed: ventilation system, closed water refrigeration circuit, internal TV system, detection and extinction fire system and emergency power group. It must be emphasized that the best attention was given to the conception and efficiency of the interlock safety systems. This facility will be utilized mainly for radiosterilization of medical articles and decontamination of wine cork stoppers. (author)

  3. Gamma irradiation service in Mexico

    International Nuclear Information System (INIS)

    In 1980 it was installed in Mexico, on the National Institute of Nuclear Research, an irradiator model J S-6500 of a canadian manufacture. Actually, this is the greatest plant in the Mexican Republic that offers a gamma irradiation process at commercial level to diverse industries. However, seeing that the demand for sterilize those products were not so much as the irradiation capacity it was opted by the incursion in other types of products. During 17 years had been irradiated a great variety of products grouped of the following form: dehydrated foods, disposable products for medical use, cosmetics, medicaments, various. Nowadays the capacity of the irradiator is saturated virtue of it is operated the 24 hours during the 365 days of the year and only its operation is suspended by the preventive and corrective maintenance. However, the fresh food market does not be attended since this irradiator was designed for doses greater than 10 kGy (1.0 Mrad)

  4. Gamma Knife Radiosurgery for Acromegaly

    Directory of Open Access Journals (Sweden)

    John D. Rolston

    2012-01-01

    Full Text Available Acromegaly is debilitating disease occasionally refractory to surgical and medical treatment. Stereotactic radiosurgery, and in particular Gamma Knife surgery (GKS, has proven to be an effective noninvasive adjunct to traditional treatments, leading to disease remission in a substantial proportion of patients. Such remission holds the promise of eliminating the need for expensive medications, along with side effects, as well as sparing patients the damaging sequelae of uncontrolled acromegaly. Numerous studies of radiosurgical treatments for acromegaly have been carried out. These illustrate an overall remission rate over 40%. Morbidity from radiosurgery is infrequent but can include cranial nerve palsies and hypopituitarism. Overall, stereotactic radiosurgery is a promising therapy for patients with acromegaly and deserves further study to refine its role in the treatment of affected patients.

  5. Modulated gamma ray beam absorptiometer

    International Nuclear Information System (INIS)

    The purpose of this paper is to describe the study and operating of a heavy elements content measuring instrument. This apparatus (French patent n0 2184533, December 16, 1974) uses the absorption of a modulated gamma ray beam to measure the concentration of 5 to 500 g per litre uranium of plutonium solutions with an over 1% accuracy. The activity of the fission products present in the solution may rise to 60 Ci/l. An automatic device suppresses all daily checkings and adjustements. The tension obtained is proportional to the content of the heavy element being measured. The influence of the nitric acid content is twenty times as weak as in the case of a conventional densimeter. This apparatus is particularly adapted to fuel reprocessing plants

  6. A new measurement of the rare decay eta -> pi^0 gamma gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

    Energy Technology Data Exchange (ETDEWEB)

    Nefkens, B M; Prakhov, S; Aguar-Bartolom��, P; Annand, J R; Arends, H J; Bantawa, K; Beck, R; Bekrenev, V; Bergh��user, H; Braghieri, A; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F; Collicott, C; Costanza, S; Danilkin, I V; Denig, A; Demissie, B; Dieterle, M; Downie, E J; Drexler, P; Fil' kov, L V; Fix, A; Garni, S; Glazier, D I; Gregor, R; Hamilton, D; Heid, E; Hornidge, D; Howdle, D; Jahn, O; Jude, T C; Kashevarov, V L; K��ser, A; Keshelashvili, I; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Kruglov, S; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J; Maghrbi, Y; Mancel, J; Manley, D M; McNicoll, E F; Mekterovic, D; Metag, V; Mushkarenkov, A; Nikolaev, A; Novotny, R; Oberle, M; Ortega, H; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Polonski, A; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sikora, M H; Starostin, A; Strakovsky, I I; Strub, T; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Werthmueller, D; Witthauer, L

    2014-08-01

    A new measurement of the rare, doubly radiative decay eta->pi^0 gamma gamma was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Gamma(eta->pi^0 gamma gamma), on the two-photon invariant mass squared, m^2(gamma gamma), as well as a new, more precise value for the decay width, Gamma(eta->pi^0 gamma gamma) = (0.33+/-0.03_tot) eV, are based on analysis of 1.2 x 10^3 eta->pi^0 gamma gamma decays from a total of 6 x 10^7 eta mesons produced in the gamma p -> eta p reaction. The present results for dGamma(eta->pi^0 gamma gamma)/dm^2(gamma gamma) are in good agreement with previous measurements and recent theoretical calculations for this dependence.

  7. Treatment with anti-interferon-gamma monoclonal antibodies modifies experimental autoimmune encephalomyelitis in interferon-gamma receptor knockout mice

    DEFF Research Database (Denmark)

    Espejo, C; Penkowa, M; Sáez-Torres, I;

    2001-01-01

    The role of interferon-gamma (IFN-gamma) in the pathogenesis of multiple sclerosis and experimental autoimmune encephalomyelitis (EAE) is still controversial. We have studied the function of IFN-gamma and its receptor in the EAE model using two different IFN-gamma receptor knockout (IFN-gamma R......(-/-)) mouse types: C57Bl/6x129Sv, with a disruption of the IFN-gamma receptor cytoplasmic domain, and 129Sv, homozygous for a disrupted IFN-gamma receptor gene. Mice were immunized with peptide 40-55 from rat myelin oligodendrocyte glycoprotein. A subgroup of mice was treated with anti-IFN-gamma monoclonal...

  8. Search for the decays $J/\\psi\\to\\gamma \\rho \\phi$ and $J/\\psi\\to\\gamma \\rho \\omega$

    CERN Document Server

    Bai, J Z; Cai, X; Chen, H F; Chen, H S; Chen, H X; Chen, J C; Chen, Jin; Chen, Y B; Chu, Y P; Dai, Y S; Diao, L Y; Deng, Z Y; Dong, Q F; Du, S X; Fang, J; Fang, S S; Fu, C D; Gao, C S; Gao, Y N; Gu, S D; Gu, Y T; Guo, Y N; Guo, Z J; Harris, F A; He, K L; He, M; Heng, Y K; Hou, J; Hu, H M; Hu, J H; Hu, T; Huang, G S; Huang, X T; Ji, X B; Jiang, X S; Jiang, X Y; Jiao, J B; Jin, D P; Jin, S; Lai, Y F; Li, G; Li, H B; Li, J; Li, R Y; Li, S M; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Liang, Y F; Liao, H B; Liu, B J; Liu, C X; Liu, F; Fang Liu; Liu, H H; Liu, H M; Liu, J; Liu, J B; Liu, J P; Liu, Jian; Liu, Q; Liu, R G; Liu, Z A; Lou, Y C; Lu, F; Lu, G R; Lu, J G; Luo, C L; Ma, F C; Ma, H L; Ma, L L; Ma, Q M; Mao, Z P; Mo, X H; Nie, J; Olsen, S L; Ping, R G; Qi, N D; Qin, H; Qiu, J F; Ren, Z Y; Rong, G; Ruan, X D; Shan, L Y; Shang, L; Shen, C P; Shen, D L; Shen, X Y; Sheng, H Y; Sun, H S; Sun, S S; Sun, Y Z; Sun, Z J; Tang, X; Tong, G L; Varner, G S; Wang, D Y; Wang, L; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Y F; Wang, Z; Wang, Z Y; Wang, Zheng; Wei, C L; Wei, D H; Weng, Y; Wu, N; Xia, X M; Xie, X X; Xu, G F; Xu, X P; Xu, Y; Yan, M L; Yang, H X; Yang, Y X; Ye, M H; Ye, Y X; Yu, G W; Yuan, C Z; Yuan, Y; Zang, S L; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C C; Zhang, D H; Zhang, H Q; Zhang, H Y; Zhang, J W; Zhang, J Y; Zhang, S H; Zhang, X Y; Zhang, Yiyun; Zhang, Z X; Zhang, Z P; Zhao, D X; Zhao, J W; Zhao, M G; Zhao, P P; Zhao, W R; Zhao, Z G; Zheng, H Q; Zheng, J P; Zheng, Z P; Zhou, L; Zhu, K J; Zhu, Q M; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, B A; Zhuang, X A; Zou, B S

    2007-01-01

    Using 58 million $J/\\psi$ events collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Positron Collider, the decays $J/\\psi\\to \\gamma\\phi\\rho$ and $J/\\psi\\to \\gamma\\omega\\rho$ are searched for, and upper limits on their branching fractions are reported at the 90% C. L. No clear structures are observed in the $\\gamma \\rho$, $\\gamma \\phi$, or $\\rho \\phi $ mass spectra for $J/\\psi\\to \\gamma\\phi\\rho$ nor in the $\\gamma \\rho$, $\\gamma \\omega$, or $\\rho \\omega$ mass spectra for $J/\\psi\\to \\gamma\\omega\\rho$.

  9. A separation of electrons and protons in the GAMMA-400 gamma-ray telescope

    CERN Document Server

    Leonov, A A; Bonvicini, V; Topchiev, N P; Adriani, O; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Bergstrom, L; Berti, E; Bigongiari, G; Bobkov, S G; Boezio, M; Bogomolov, E A; Bonechi, S; Bongi, M; Bottai, S; Castellini, G; Cattaneo, P W; Cumani, P; Dedenko, G L; De Donato, C; Dogiel, V A; Gorbunov, M S; Gusakov, Yu V; Hnatyk, B I; Kadilin, V V; Kaplin, V A; Kaplun, A A; Kheymits, M D; Korepanov, V E; Larsson, J; Loginov, V A; Longo, F; Maestro, P; Marrocchesi, P S; Mikhailov, V V; Mocchiutti, E; Moiseev, A A; Mori, N; Moskalenko, I V; Naumov, P Yu; Papini, P; Pearce, M; Picozza, P; Popov, A V; Rappoldi, A; Ricciarini, S; Runtso, M F; Ryde, F; Serdin, O V; Sparvoli, R; Spillantini, P; Suchkov, S I; Tavani, M; Taraskin, A A; Tiberio, A; Tyurin, E M; Ulanov, M V; Vacchi, A; Vannuccini, E; Vasilyev, G I; Yurkin, Yu T; Zampa, N; Zirakashvili, V N; Zverev, V G

    2015-01-01

    The GAMMA-400 gamma-ray telescope is intended to measure the fluxes of gamma rays and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV. Such measurements concern with the following scientific goals: search for signatures of dark matter, investigation of gamma-ray point and extended sources, studies of the energy spectra of Galactic and extragalactic diffuse emission, studies of gamma-ray bursts and gamma-ray emission from the active Sun, as well as high-precision measurements of spectra of high-energy electrons and positrons, protons, and nuclei up to the knee. The main components of cosmic rays are protons and helium nuclei, whereas the part of lepton component in the total flux is ~10E-3 for high energies. In present paper, the capability of the GAMMA-400 gamma-ray telescope to distinguish electrons and positrons from protons in cosmic rays is investigated. The individual contribution to the proton rejection is studied for each detector system of the GAMMA-400 gamma-ray tel...

  10. Comparison of gamma-gamma Phase Coarsening Responses of Three Powder Metal Disk Superalloys

    Science.gov (United States)

    Gabb, T. P.; Gayda, J.; Johnson, D. F.; MacKay, R. A.; Rogers, R. B.; Sudbrack, C. K.; Garg, A.; Locci, I. E.; Semiatin, S. L.; Kang, E.

    2016-01-01

    The phase microstructures of several powder metal (PM) disk superalloys were quantitatively evaluated. Contents, chemistries, and lattice parameters of gamma and gamma strengthening phase were determined for conventionally heat treated Alloy 10, LSHR, and ME3 superalloys, after electrolytic phase extractions. Several of long term heat treatments were then performed, to allow quantification of the precipitation, content, and size distribution of gamma at a long time interval to approximate equilibrium conditions. Additional coarsening heat treatments were performed at multiple temperatures and shorter time intervals, to allow quantification of the precipitation, contents and size distributions of gamma at conditions diverging from equilibrium. Modest differences in gamma and gamma lattice parameters and their mismatch were observed among the alloys, which varied with heat treatment. Yet, gamma coarsening rates were very similar for all three alloys in the heat treatment conditions examined. Alloy 10 had higher gamma dissolution and formation temperatures than LSHR and ME3, but a lower lattice mismatch, which was slightly positive for all three alloys at room temperature. The gamma precipitates of Alloy 10 appeared to remain coherent at higher temperatures than for LSHR and ME3. Higher coarsening rates were observed for gamma precipitates residing along grain boundaries than for those within grains in all three alloys, during slow-moderate quenching from supersolvus solution heat treatments, and during aging at temperatures of 843 C and higher.

  11. Human gamma oscillations during slow wave sleep.

    Directory of Open Access Journals (Sweden)

    Mario Valderrama

    Full Text Available Neocortical local field potentials have shown that gamma oscillations occur spontaneously during slow-wave sleep (SWS. At the macroscopic EEG level in the human brain, no evidences were reported so far. In this study, by using simultaneous scalp and intracranial EEG recordings in 20 epileptic subjects, we examined gamma oscillations in cerebral cortex during SWS. We report that gamma oscillations in low (30-50 Hz and high (60-120 Hz frequency bands recurrently emerged in all investigated regions and their amplitudes coincided with specific phases of the cortical slow wave. In most of the cases, multiple oscillatory bursts in different frequency bands from 30 to 120 Hz were correlated with positive peaks of scalp slow waves ("IN-phase" pattern, confirming previous animal findings. In addition, we report another gamma pattern that appears preferentially during the negative phase of the slow wave ("ANTI-phase" pattern. This new pattern presented dominant peaks in the high gamma range and was preferentially expressed in the temporal cortex. Finally, we found that the spatial coherence between cortical sites exhibiting gamma activities was local and fell off quickly when computed between distant sites. Overall, these results provide the first human evidences that gamma oscillations can be observed in macroscopic EEG recordings during sleep. They support the concept that these high-frequency activities might be associated with phasic increases of neural activity during slow oscillations. Such patterned activity in the sleeping brain could play a role in off-line processing of cortical networks.

  12. Gamma-ray Astronomy and GLAST

    Science.gov (United States)

    McEnery, Julie

    2007-01-01

    The high energy gamma-ray (30 MeV to 100 GeV) sky has been relatively poorly studied. Most of our current knowledge comes from observations made by the Energetic Gamma Ray Experiment Telescope (EGRET) detector on the Compton Gamma Ray Observatory (CGRO), which revealed that the GeV gamma-ray sky is rich and vibrant. Studies of astrophysical objects at GeV energies are interesting for several reasons: The high energy gamma-rays are often produced by a different physical process than the better studied X-ray and optical emission, thus providing a unique information for understanding these sources. Production of such high-energy photons requires that charged particles are accelerated to equally high energies, or much greater. Thus gamma-ray astronomy is the study of extreme environments, with natural and fundamental connections to cosmic-ray and neutrino astrophysics. The launch of GLAST in 2008 will herald a watershed in our understanding of the high energy gamma-ray sky, providing dramatic improvements in sensitivity, angular resolution and energy range. GLAST will open a new avenue to study our Universe as well as to answer scientific questions EGRET observations have raised. In this talk, I will describe the GLAST instruments and capabilities and highlight some of the science we expect to address.

  13. Gamma-Ray Burst Physics with GLAST

    Energy Technology Data Exchange (ETDEWEB)

    Omodei, N.; /INFN, Pisa

    2006-10-06

    The Gamma-ray Large Area Space Telescope (GLAST) is an international space mission that will study the cosmos in the energy range 10 keV-300 GeV, the upper end of which is one of the last poorly observed region of the celestial electromagnetic spectrum. The ancestor of the GLAST/LAT was the Energetic Gamma Ray Experiment Telescope (EGRET) detector, which flew onboard the Compton Gamma Ray Observatory (CGRO). The amount of information and the step forward that the high energy astrophysics made thanks to its 9 years of observations are impressive. Nevertheless, EGRET uncovered the tip of the iceberg, raising many questions, and it is in the light of EGRET's results that the great potential of the next generation gamma-ray telescope can be appreciated. GLAST will have an imaging gamma-ray telescope, the Large Area Telescope (LAT) vastly more capable than instruments own previously, as well as a secondary instrument, the GLAST Bursts Monitor, or GBM, to augment the study of gamma-ray bursts. Gamma-Ray Bursts (GRBs) science is one of the most exciting challenges for the GLAST mission, exploring the high energy emission of one of the most intense phenomena in the sky, shading light on various problems: from the acceleration of particles to the emission processes, to more exotic physics like Quantum Gravity effect. In this paper we report the work done so far in the simulation development as well as the study of the LAT sensitivity to GRB.

  14. Gamma-ray emission from globular clusters

    CERN Document Server

    Tam, P H Thomas; Hui, C Y

    2012-01-01

    Over the last few years, the fruitful data provided by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope has revolutionized our understanding of high-energy processes in globular clusters, particularly those involving compact objects like millisecond pulsars (MSPs). Gamma-ray emission between 100 MeV to 10 GeV has been detected from more than a dozen globular clusters in our Galaxy, most notably 47 Tucanae and Terzan 5. Based on a sample of known gamma-ray globular clusters, empirical relations between the gamma-ray luminosity and properties of globular clusters such as stellar encounter rate, metallicity, as well as optical and infrared photon energy density in the cluster, have been derived. The gamma-ray spectra are generally described by a power law with a cut-off at a few GeV. Together with the detection of pulsed gamma-rays from a millisecond pulsar in a globular cluster, such spectral signature gives support that gamma-rays from globular clusters are collective curvature emission from...

  15. Calibration of nuclear medicine gamma counters

    International Nuclear Information System (INIS)

    In this paper the practical problem of nuclear medicine gamma counters calibration has been solved by using dose calibrators CRC-15R with standard error ±5%. The samples from technetium generators have been measured both by dose calibrators CRC-15R and gamma counter ICN Gamma 3.33 taking into account decay correction. Only the linear part of the curve has practical meaning. The advantage of this procedure satisfies the requirements from international standards: the calibration of sources used for medical exposure be traceable to a standard dosimetry laboratory and radiopharmaceuticals for nuclear medicine procedures be calibrated in terms of activity of the radiopharmaceutical to be administered. (author)

  16. Mathematical efficiency calibration in gamma spectroscopy

    CERN Document Server

    Kaminski, S; Wilhelm, C

    2003-01-01

    Mathematical efficiency calibration with the LabSOCS software was introduced for two detectors in the measurement laboratory of the Central Safety Department of Forschungszentrum Karlsruhe. In the present contribution, conventional efficiency calibration of gamma spectroscopy systems and mathematical efficiency calibration with LabSOCS are compared with respect to their performance, uncertainties, expenses, and results. It is reported about the experience gained, and the advantages and disadvantages of both methods of efficiency calibration are listed. The results allow the conclusion to be drawn that mathematical efficiency calibration is a real alternative to conventional efficiency calibration of gamma spectroscopy systems as obtained by measurements of mixed gamma ray standard sources.

  17. The propagation of gamma quanta in matter

    CERN Document Server

    Lejpunskij, Ovsej Ilich; Sakharov, Vsevolod Nikolaevich

    1965-01-01

    The Propagation of Gamma Quanta in Matter deals with various problems of the propagation and absorption of gamma quanta in matter, particularly the occurrence of multiple scattering of radiation. The ultimate objective is to determine the material, size, and configuration that will ensure the safe absorption of nuclear radiation. Shield design problems are given, the solution of which is achieved using numerical data presented in graphs and tables. This volume is comprised of three chapters and begins with an overview of the interaction of gamma radiation with matter and multiple scattering of

  18. Gamma knife: Distribution of dose rates

    International Nuclear Information System (INIS)

    In order to establish necessary data for dimensioning treatment room shielding for the first gamma knife in Austria we made use of results of measurements taken from existing installations abroad. Since there are no standardised rules for dimensioning gamma knife sites we felt that further research was necessary. Thus we conducted measurements of the leakage radiation with closed shielding doors and of the dose rate in the treatment room using a Rando Alderson phantom. This paper is intended as additional help for further installations of gamma knifes

  19. GAMMA-KNIFE: OPERATION OHNE SKALPELL

    OpenAIRE

    АБЛЯЕВА В.И.; НИКОЛАЕВА Н.А.; ДЕНИСОВА О.С.

    2015-01-01

    Das Gamma-Knife ist ein Operationsroboter, mit dem Ärzte durch Photonenstrahlen im Körper operieren können. Die Photonen beschädigen die DNA von Zellen, so dass diese sich nicht mehr teilen können. Gutartige Tumoren vernarben in den Wochen und Monaten nach der Behandlung, bösartige zerfallen. Mit dem Gamma-Knife können unterschiedliche Arten von Tumoren behandelt werden, gutartige ebenso wie bösartige. Zu den Diagnosen, bei denen das Gamma-Knife in Frage kommt, gehören zum Beispiel Akustikusn...

  20. Modeling gamma-ray bursts

    Science.gov (United States)

    Maxham, Amanda

    Discovered serendipitously in the late 1960s, gamma-ray bursts (GRBs) are huge explosions of energy that happen at cosmological distances. They provide a grand physical playground to those who study them, from relativistic effects such as beaming, jets, shocks and blastwaves to radiation mechanisms such as synchrotron radiation to galatic and stellar populations and history. Through the Swift and Fermi space telescopes dedicated to observing GRBs over a wide range of energies (from keV to GeV), combined with accurate pinpointing that allows ground based follow-up observations in the optical, infrared and radio, a rich tapestry of GRB observations has emerged. The general picture is of a mysterious central engine (CE) probably composed of a black hole or neutron star that ejects relativistic shells of matter into intense magnetic fields. These shells collide and combine, releasing energy in "internal shocks" accounting for the prompt emission and flaring we see and the "external shock" or plowing of the first blastwave into the ambient surrounding medium has well-explained the afterglow radiation. We have developed a shell model code to address the question of how X-ray flares are produced within the framework of the internal shock model. The shell model creates randomized GRB explosions from a central engine with multiple shells and follows those shells as they collide, merge and spread, producing prompt emission and X-ray flares. We have also included a blastwave model, which can constrain X-ray flares and explain the origin of high energy (GeV) emission seen by the Fermi telescope. Evidence suggests that gamma-ray prompt emission and X-ray flares share a common origin and that at least some flares can only be explained by long-lasting central engine activity. We pay special attention to the time history of central engine activity, internal shocks, and observed flares. We calculate the gamma-ray (Swift/BAT band) and X-ray (Swift/XRT band) lightcurves for arbitrary

  1. Dipole strength in 144Sm studied via (gamma,n), (gamma,p) and (gamma,alpha) reactions

    CERN Document Server

    Nair, Chithra; Erhard, Martin; Bemmerer, Daniel; Beyer, Roland; Grosse, Eckart; Kosev, Krasimir; Marta, Michele; Rusev, Gencho; Schilling, Klaus-Dieter; Schwengner, Ronald; Wagner, Andreas

    2010-01-01

    Photoactivation measurements on 144Sm have been performed with bremsstrahlung endpoint energies from 10.0 to 15.5 MeV at the bremsstrahlung facility of the superconducting electron accelerator ELBE of Forschungszentrum Dresden-Rossendorf. The measured activation yield for the 144Sm(gamma,n) reaction is compared with the calculated yield using cross sections from previous photoneutron experiments. The activation yields measured for all disintegration channels 144Sm(gamma,n), (gamma,p) and (gamma,alpha) are compared to the yield calculated by using Hauser-Feshbach statistical models. A new parametrization of the photon strength function is presented and the yield simulated by using the modified photon strength parameters are compared to the experimental data.

  2. GAMMA-RAY AND X-RAY EMISSION FROM GAMMA-RAY-LOUD BLAZARS

    Institute of Scientific and Technical Information of China (English)

    ZHANG XIONG; ZHAO GANG; XIE GUANG-ZHONG; ZHENG GUANG-SHENG; ZHANG LI

    2001-01-01

    We present a strong correlation of the gamma-ray (above 100 MeV) mean spectral indices aγ and X-ray (1 keV)mean spectral indices cX for 34 gamma-ray-loud blazars (16 BL Lac objects and 18 flat spectrum radio quasars). Astrong correlation is also found between the gamma-ray flux densities F-γ and X-ray flux densities Fx in the low state for 47 blazars (17 BL Lac and 30 flat spectrum radio quasars). Possible correlation on the gamma-ray emission mechanism is discussed. We suggest that the main gamma-ray radiation mechanism is probably the synchrotron process. The gamma-ray emission may be somewhat different from that of BL Lac objects and flat spectrum radio quasars.

  3. A Search for the Rare Decay $B\\rightarrow\\gamma\\gamma$

    Energy Technology Data Exchange (ETDEWEB)

    del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-06-02

    We report the result of a search for the rare decay B{sup 0} {yields} {gamma}{gamma} in 426 fb{sup -1} of data, corresponding to 226 million B{sup 0}{bar B}{sup 0} pairs, collected on the {Upsilon}(4S) resonance at the PEP-II asymmetric-energy e{sup +}e{sup -} collider using the BABAR detector. We use a maximum likelihood fit to extract the signal yield and observe 21{sub -12}{sup +13} signal events with a statistical signficance of 1.9 {sigma}. This corresponds to a branching fraction {Beta}(B{sup 0} {yields} {gamma}{gamma}) = (1.7 {+-} 1.1(stat.) {+-} 0.2(syst.)) x 10{sup -7}. Based on this result, we set a 90% confidence level upper limit of {Beta}(B{sup 0} {yields} {gamma}{gamma}) < 3.2 x 10{sup -7}.

  4. Study of the Rare Decay K(L) ---> pi0 gamma gamma at KTeV

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jianbo; /Arizona U.

    2007-08-01

    The authors study on the rare decay K{sub L} {yields} {pi}{sup 0}{gamma}{gamma}, measure a{sub V}, and branching ratio by analyzing 96, 97 and 99 data. The measurements were taken by KTeV at Fermi National Accelerator Laboratory. After all cuts, they have 1982 K{sub L} {yields} {pi}{sup 0}{gamma}{gamma} candidate. The background level is estimated as 30%. K{sub L} {yields} {pi}{sup 0}{gamma}{gamma} branching ratio is measured as (1.29 {+-} 0.03(stat) {+-} 0.04(sys)) x 10{sup -6}. By using D'Ambrosio's theory to fit a{sub V}, a{sub V} = -(-0.31 {+-} 0.05(stat) {+-} 0.07(sys)).

  5. Method of incident low-energy gamma-ray direction reconstruction in the GAMMA-400 gamma-ray space telescope

    Science.gov (United States)

    Kheymits, M. D.; Leonov, A. A.; Zverev, V. G.; Galper, A. M.; Arkhangelskaya, I. V.; Arkhangelskiy, A. I.; Suchkov, S. I.; Topchiev, N. P.; Yurkin, Yu T.; Bakaldin, A. V.; Dalkarov, O. D.

    2016-02-01

    The GAMMA-400 gamma-ray space-based telescope has as its main goals to measure cosmic γ-ray fluxes and the electron-positron cosmic-ray component produced, theoretically, in dark-matter-particles decay or annihilation processes, to search for discrete γ-ray sources and study them in detail, to examine the energy spectra of diffuse γ-rays — both galactic and extragalactic — and to study gamma-ray bursts (GRBs) and γ-rays from the active Sun. Scientific goals of GAMMA-400 telescope require fine angular resolution. The telescope is of a pair-production type. In the converter-tracker, the incident gamma-ray photon converts into electron-positron pair in the tungsten layer and then the tracks are detected by silicon- strip position-sensitive detectors. Multiple scattering processes become a significant obstacle in the incident-gamma direction reconstruction for energies below several gigaelectronvolts. The method of utilising this process to improve the resolution is proposed in the presented work.

  6. Measurement of \\Gamma(\\eta -> \\pi^+\\pi^-\\gamma)/\\Gamma(\\eta -> \\pi^+\\pi^-\\pi^0) with the KLOE Detector

    CERN Document Server

    Babusci, D; Balwierz-Pytko, I; Bencivenni, G; Bini, C; Bloise, C; Bocci, V; Bossi, F; Branchini, P; Budano, A; Caldeira Balkest, L; Capon, G; Ceradini, F; Ciambrone, P; Czerwinski, E; Dane, E; De Lucia, E; De Robertis, G; De Santis, A; De Simone, P; Di Domenico, A; Di Donato, C; Di Micco, B; Di Salvo, R; Domenici, D; Erriquez, O; Fanizzi, G; Fantini, A; Felici, G; Fiore, S; Franzini, P; Gauzzi, P; Giardina, G; Giovannella, S; Gonnella, F; Graziani, E; Happacher, F; Hoistad, B; Iafolla, L; Jacewicz, M; Johansson, T; Kupsc, A; Lee-Franzini, J; Leverington, B; Loddo, F; Loffredo, S; Mandaglio, G; Martemianov, M; Martini, M; Mascolo, M; Messi, R; Miscetti, S; Morello, G; Moricciani, D; Moskal, P; Nguyen, F; Passeri, A; Patera, V; Prado Longhi, I; Ranieri, A; Redmer, C.F; Santangelo, P; Sarra, I; Schioppa, M; Sciascia, B; Silarski, M; Taccini, C; Tortora, L; Venanzoni, G; Versaci, R; Wislicki, W; Wolke, M; Xu, G; Zdebik, J

    2013-01-01

    The ratio R_{\\eta}=\\Gamma(\\eta -> \\pi^+\\pi^-\\gamma)/\\Gamma(\\eta -> \\pi^+\\pi^-\\pi^0) has been measured by analyzing 22 million \\phi \\to \\eta \\gamma decays collected by the KLOE experiment at DA\\PhiNE, corresponding to an integrated luminosity of 558 pb^{-1}. The \\eta \\to \\pi^+\\pi^-\\gamma proceeds both via the \\rho resonant contribution, and possibly a non-resonant direct term, connected to the box anomaly. Our result, R_{\\eta}= 0.1856\\pm 0.0005_{stat} \\pm 0.0028_{syst}, points out a sizable contribution of the direct term to the total width. The di-pion invariant mass for the \\eta -> \\pi^+\\pi^-\\gamma decay could be described in a model-independent approach in terms of a single free parameter, \\alpha. The determined value of the parameter \\alpha is \\alpha = (1.32 \\pm 0.08_{stat} +0.10/-0.09_{syst}\\pm 0.02_{theo}) GeV^{-2}

  7. Electron-gamma directional correlations

    International Nuclear Information System (INIS)

    The theory of the angular correlation between conversion electrons and gamma rays is briefly outlined. The experimental methods used for the study of the electron-gamma correlation are described. The effects of the formation of a hole and the hyperfine structure magnetic coupling dependent on time are then considered. The experimental results showed that the attenuations found for different metallic media plainly conform to a simple quadrupolar interaction mechanism. For a source surrounded by an insulator, however, the results show that a rapidly disappearing coupling occurs as a supplement to the quadrupolar interaction mechanism. This coupling attenuates the angular correlation by about 75% of the non-perturbed value. It was concluded that for an intermediate half life of the level of the order of the nanosecond, the attenuations produced by the secondary effects of the hole formation can not be completely neglected. The metallic media considered were Ag, Au, Al, and Ga. In the study of E2 conversion processes, the radical matrix elements governing the E2 conversion process in the 412-KeV transition of 198Hg were determined. The results exclude the presence of dynamic contributions within the limits of experimental error. The values b2 (E2) and α-k (E2) obtained indirectly from the experimentally determined b4 particle parameter are in complete agreement with the theoretical values obtained by applying the corrections due to the shielding effect and to the finite dimension of the nucleus and excluding the dynamic contributions. The value for the internal conversion coefficient was also in good agreement. Experimental results from the intensity ratios between the peak and the continuum, however, seem to show significant deviations with respect to other experimental and theoretical values. There is good agreement between experimental and theoretical results on the internal conversion of 203Tl, 201Tl, and 181Ta. The theory of internal conversion process containing

  8. Gamma ray astronomy and the COS-B satellite

    International Nuclear Information System (INIS)

    The European satellite COS-B, operating in space for almost seven years, has produced a full chart of the sky in gamma radiation. This chart is discussed in detail, as well as gamma astronomy, high energy photons, gamma photons, strange stars, young pulsars, stars seething with activity and quasar 3C273. Other gamma astronomy programmes are briefly mentioned. (U.K.)

  9. GGT (Gamma-Glutamyl Transferase) Test

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? GGT Share this page: Was this page helpful? Also ... How is it used? The gamma-glutamyl transferase (GGT) test may be used to determine the cause ...

  10. Gamma-Ray Astrophysics NSSTC Fermi GBM

    Data.gov (United States)

    National Aeronautics and Space Administration — The Fermi Gamma-Ray Burst Monitor (GBM) is not a pointed or imaging instrument. To determine fluxes for known sources, we measure the change in the count rate...

  11. Gamma rays from clusters of galaxies

    CERN Document Server

    Blasi, P; Brunetti, G; Blasi, Pasquale; Gabici, Stefano; Brunetti, Gianfranco

    2007-01-01

    Clusters of galaxies and the large scale filaments that connect neighboring clusters are expected to be sites of acceleration of charged particles and sources of non-thermal radiation from radio frequencies to gamma rays. Gamma rays are particularly interesting targets of investigation, since they may provide precious information on the nature and efficiency of the processes of acceleration and magnetic confinement of hadrons within clusters of galaxies. Here we review the status of viable scenarios that lead to the production of gamma rays from large scale structures and are compatible with the multifrequency observations that are already available. We also discuss the possibility of detection of gamma rays with space-borne telescopes such as GLAST and ground based Cherenkov telescopes, and the physical information that may be gathered from such observations.

  12. Project Marna Natural Gamma Radiation MAP

    International Nuclear Information System (INIS)

    The confusion created by the accident that occurred in one of the Chernobyl reactors in April of 1986 made the general public and governments aware of the need for improved monitoring of environmental radiation levels. The levels of total gamma radiation or total gamma exposure rate over large areas reached values as high as 400 micro Roentgen/hour (mu R/h) and at points exceeded 1000 mu R/h. It should be borne in mind that, depending on the type of geological formations, normal values range from 5 to 30 mu R/h. The IAEA recommended to all countries that natural gamma radiation maps be made available to evaluate the levels of natural gamma radiation and possible increases, and it also indicated its concern that information be standardized. In addition, it stressed the advisability of using data obtained from uranium prospecting. (Author)

  13. Elastic scattering of gamma radiation in solids

    International Nuclear Information System (INIS)

    The elastic scattering of gamma rays in solids is studied: Rayleigh scattering as well as Bragg scattering in Laue geometries. We measured Rayleigh cross sections for U, Pb, Pt, W, Sn, Ag, Mo, Cd, Zn, and Cu with gamma energies ranging from 60 to 660 KeV and angles between 50 and 1400. The experimental data are compared with form factor theories and second order perturbation theories and the limits of validity of both are established. In the 60 KeV experiment, a competition between Rayleigh and Bragg effects is found in the region of low momentum transfer. The Bragg experiments were performed using the gamma ray diffractometer from the Hahn-Meitner Institut (Berlin) with gammas of 317 KeV and angles up to 20. In particular, we studied the effect of annealing in nearly perfect Czochralski Silicon crystals with high perfection in the crystallographic structure. The results are compared with Kinematical and Dynamical theories. (author)

  14. Precision measurements of gamma-ray intensities

    International Nuclear Information System (INIS)

    To determine relative intensities of gamma rays in the region of 280 to 2750 keV, Ge(Li) detectors were calibrated with standard sources and cascade gamma-ray sources. Decay rates of the standard sources were determined by means of the 4πβ-γ or 4πX-γ coincidence method. Experimental conditions were improved and spectra were carefully analyzed. Relative gamma-ray intensities of 56Co, 88Y, sup(110m)Ag, 133Ba, 134Cs, 152Eu, 154Eu, 192Ir and 207Bi were determined within the accuracy of about 0.5% for strong gamma rays. Intensities per decays were obtained from the relative intensities for most of the nuclides. (author)

  15. Spatial distribution of the backscattered gamma radiation

    International Nuclear Information System (INIS)

    The results were calculated for an isotropic point photon source on an infinite layer of the material using the Monte Carlo method. The values of the effective depth of gamma ray penetration are also given for axial geometry. (author)

  16. Gamma ray auto absorption correction evaluation methodology

    International Nuclear Information System (INIS)

    Neutron activation analysis (NAA) is a well established nuclear technique, suited to investigate the microstructural or elemental composition and can be applied to studies of a large variety of samples. The work with large samples involves, beside the development of large irradiation devices with well know neutron field characteristics, the knowledge of perturbing phenomena and adequate evaluation of correction factors like: neutron self shielding, extended source correction, gamma ray auto absorption. The objective of the works presented in this paper is to validate an appropriate methodology for gamma ray auto absorption correction evaluation for large inhomogeneous samples. For this purpose a benchmark experiment has been defined - a simple gamma ray transmission experiment, easy to be reproduced. The gamma ray attenuation in pottery samples has been measured and computed using MCNP5 code. The results show a good agreement between the computed and measured values, proving that the proposed methodology is able to evaluate the correction factors. (authors)

  17. Gamma beam system at ELI-NP

    Energy Technology Data Exchange (ETDEWEB)

    Ur, Calin Alexandru, E-mail: calin.ur@eli-np.ro [Extreme Light Infrastructure, IFIN-HH, Magurele-Bucharest (Romania)

    2015-02-24

    The Gamma Beam System of ELI-NP will produce brilliant, quasi-monochromatic gamma-ray beams via Inverse Compton Scattering of short laser pulses on relativistic electron beam pulses. The scattered radiation is Doppler upshifted by more than 1,000,000 times and is forward focused in a narrow, polarized, tunable, laser-like beam. The gamma-ray beam at ELI-NP will be characterized by large spectral density of about 10{sup 4} photons/s/eV, narrow bandwidth (< 0.5%) and tunable energy from 200 keV up to about 20 MeV. The Gamma Beam System is a state-of-the-art equipment employing techniques and technologies at the limits of the present-day's knowledge.

  18. The $e^+ e^- \\to Z\\gamma\\gamma \\to q\\overline{q}\\gamma\\gamma$ Reaction at LEP and Constraints on Anomalous Quartic Gauge Boson Couplings

    CERN Document Server

    Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, Michael; Doria, A; Dova, M T; Duchesneau, D; Echenard, B; Eline, A; El-Mamouni, H; Engler, A; Eppling, F J; Ewers, A; Extermann, Pierre; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hakobyan, R S; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Latt, J; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Ofierzynski, R A; Organtini, G; Palomares, C; Pandoulas, D; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofiev, D O; Prokofev, D; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Roux, B; Rubio, Juan Antonio; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S V; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R P; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wallraff, W; Wang, X L; Wang, Z M; Weber, M; Wienemann, P; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M

    2002-01-01

    The cross section of the process e^+ e^- -> Z \\gamma\\gamma -> qq~ \\gamma \\gamma is measured with 215 pb^-1 of data collected with the L3 detector during the final LEP run at centre-of-mass energies around 205 GeV and 207 GeV. No deviation from the Standard Model expectation is observed. The full data sample of 713 pb^-1, collected above the Z resonance, is used to constrain the coefficients of anomalous quartic gauge boson couplings to: -0.02 GeV^-2 < a_0/\\Lambda^2 < 0.03 GeV^-2 and -0.07 GeV^-2 < a_c/\\Lambda^2 < 0.05 GeV^-2, at 95% confidence level.

  19. Single superparticle production via $\\gamma\\gamma$ collision with explicit R-parity violation

    CERN Document Server

    Chaichian, Masud; Yu, Z H

    2001-01-01

    We study the single production of scalar neutrinos or charginos via $\\gamma\\gamma$ collision in an R-parity ($R_{p}$) violating supersymmetric model. It may be possible to detect a sneutrino or a chargino at a Linear Collider (LC) in $\\gamma \\gamma$ operation mode, as a test of supersymmetry and $R_p$-violation. Because of the clean background in LC, stringent constraints on $R_p$ violating parameters can be obtained even if the process cannot be observed at the future Linear Collider.

  20. Search for anomalous quartic $ZZ\\gamma\\gamma$ couplings in photon-photon collisions

    CERN Document Server

    Köksal, M; Senol, A

    2016-01-01

    The self-couplings of the electroweak gauge bosons are completely specified by the non-Abelian gauge nature of the Standard Model (SM). The direct study of these couplings provides a significant opportunity to test the validity of the SM and the existence of new physics beyond the SM up to the high energy scale. For this reason, we investigate the potential of the processes $\\gamma\\gamma\\rightarrow ZZ$, $e^{-}\\gamma\\rightarrow e^{-}\\gamma^{*}\\gamma \\rightarrow e^{-}Z\\, Z$ and $e^{+}e^{-}\\rightarrow e^{+}\\gamma^{*} \\gamma^{*} e^{-} \\rightarrow e^{+}\\, Z\\, Z\\, e^{-}$ to examine the anomalous quartic couplings of $ZZ\\gamma\\gamma$ vertex at the Compact Linear Collider (CLIC) with center-of-mass energies $0.35, 1.4$ and $3$ TeV. We calculate $95\\%$ confidence level sensitivities on the dimension-8 parameters with various values of the integrated luminosity. We show that the best bounds on the anomalous $\\frac{f_{M2}}{\\Lambda^{4}}$, $\\frac{f_{M3}}{\\Lambda^{4}}$, $\\frac{f_{T0}}{\\Lambda^4}$ and $\\frac{f_{T9}}{\\Lambda...

  1. The HAWC Gamma-Ray Observatory: Sensitivity to Steady and Transient Sources of Gamma Rays

    CERN Document Server

    Abeysekara, A U; Alvarez, C; Álvarez, J D; Arceo, R; Arteaga-Velázquez, J C; Solares, H A Ayala; Barber, A S; Baughman, B M; Bautista-Elivar, N; Belmont, E; BenZvi, S Y; Berley, D; Rosales, M Bonilla; Braun, J; Caballero-Lopez, R A; Caballero-Mora, K S; Carramiñana, A; Castillo, M; Cotti, U; Cotzomi, J; de la Fuente, E; De León, C; DeYoung, T; Hernandez, R Diaz; Díaz-Vélez, J C; Dingus, B L; DuVernois, M A; Ellsworth, R W; Fernandez, A; Fiorino, D W; Fraija, N; Galindo, A; Garfias, F; González, L X; González, M M; Goodman, J A; Grabski, V; Gussert, M; Hampel-Arias, Z; Hui, C M; Hüntemeyer, P; Imran, A; Iriarte, A; Karn, P; Kieda, D; Kunde, G J; Lara, A; Lauer, R J; Lee, W H; Lennarz, D; Vargas, H León; Linares, E C; Linnemann, J T; Longo, M; Luna-GarcIa, R; Marinelli, A; Martinez, H; Martinez, O; Martínez-Castro, J; Matthews, J A J; Miranda-Romagnoli, P; Moreno, E; Mostafá, M; Nava, J; Nellen, L; Newbold, M; Noriega-Papaqui, R; Oceguera-Becerra, T; Patricelli, B; Pelayo, R; Pérez-Pérez, E G; Pretz, J; Rivière, C; Rosa-González, D; Salazar, H; Salesa, F; Sanchez, F E; Sandoval, A; Santos, E; Schneider, M; Silich, S; Sinnis, G; Smith, A J; Sparks, K; Springer, R W; Taboada, I; Toale, P A; Tollefson, K; Torres, I; Ukwatta, T N; Villaseñor, L; Weisgarber, T; Westerhoff, S; Wisher, I G; Wood, J; Yodh, G B; Younk, P W; Zaborov, D; Zepeda, A; Zhou, H

    2013-01-01

    The High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory is designed to record air showers produced by cosmic rays and gamma rays between 100 GeV and 100 TeV. Because of its large field of view and high livetime, HAWC is well-suited to measure gamma rays from extended sources, diffuse emission, and transient sources. We describe the sensitivity of HAWC to emission from the extended Cygnus region as well as other types of galactic diffuse emission; searches for flares from gamma-ray bursts and active galactic nuclei; and the first measurement of the Crab Nebula with HAWC-30.

  2. ICI detector for measuring gamma-ray fluxes in mixed gamma-neutron fields

    International Nuclear Information System (INIS)

    A new gamma-ray detecting device called ICI (Insulator-conductor-insulator) detector has been developed and tested. Like vacuum Compton diode (VCD) and dielectric Compton diode (DCD) generally used in pulsed gamma-ray measurements, ICI detector operates by utilization of the Compton effect and has low sensitivity to gamma-ray fluxes, very fast time response, large linearity and wide dynamic range, it is desired for using the device to measure intense and rapidly changing gamma-ray fluxes. Compared to the existing VCDs and DCDs, the detector requires no vacuum in operation and the active volume is only 2 mm thick. (authors)

  3. Measurement of the Charm Production Cross Section in gamma gamma Collisions at LEP

    CERN Document Server

    Acciarri, M; Adriani, O; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, L; Balandras, A; Baldew, S V; Todorova-Nová, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Cucciarelli, S; Dai, T S; van Dalen, J A; D'Alessandro, R; De Asmundis, R; Déglon, P L; Degré, A; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Van Dierendonck, D N; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Dufournaud, D; Duinker, P; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ewers, A; Extermann, Pierre; Fabre, M; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Hofer, H; Holzner, G; Hoorani, H; Hou, S R; Hu, Y; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Khan, R A; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Kopp, A; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Le Goff, J M; Leiste, R; Levchenko, P M; Li Chuan; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Lugnier, L; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Marian, G; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Moulik, T; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Ofierzynski, R A; Organtini, G; Oulianov, A; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Paramatti, R; Park, H K; Park, I H; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Prokofiev, D O; Prokofev, D; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Rodin, J; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Roux, B; Rubio, Juan Antonio; Ruggiero, G; Rykaczewski, H; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Seganti, A; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S V; Suter, H; Swain, J D; Szillási, Z; Sztaricskai, T; Tang, X W; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, M; Wang, X L; Wang, Z M; Weber, A; Weber, M; Wienemann, P; Wilkens, H; Wu, S X; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhu, G Y; Zhu, R Y; Zichichi, A; Zilizi, G; Zimmermann, B; Zöller, M

    2001-01-01

    Open charm production in gamma-gamma collisions is studied with data collected at e+e- centre-of-mass energies from 189 GeV to 202 GeV corresponding to a total integrated luminosity of 410 pb-1. The charm cross section sigma(gamma gamma ---> c c~ X) is measured for the first time as a function of the two-photon centre-of-mass energy in the interval from 5 GeV to 70 GeV and is compared to NLO QCD calculations.

  4. Induction of bacterial blight resistance in elite Indian rice (Oryza sativa L.) cultivars using gamma irradiation and ethyl methane sulfonate

    International Nuclear Information System (INIS)

    inoculation following standard techniques. Plants with a lesion length of less than 2.5 cm were scored as resistant. In M2 out of a population of 89045 plants, a total of 40 lines comprising 145 plants (2.46%) were resistant to bacterial blight. A maximum of 16 BB resistant mutant lines were observed in Pusa Basmati 1, whereas there were 24 in PR 106. On a line basis, 24 out of 1876 lines of PR106 segregated for BB resistance leading to a frequency of 1.279%, whereas 16 out of 1953 segregated for BB resistance leading to a frequency of 0.819% in the case of Pusa Basmati 1. When observed in terms of mutagens, 17 out of 24 mutants were induced by EMS in the case of PR 106 whereas for Pusa Basmati 1, 12 out of 16 cases the resistance was induced by gamma irradiation. In a study by Padmanabhan et al (1976) [4], 0.36% resistant and 0.65% moderately resistant plants were obtained in the M2 population derived from EMS treated variety. The rate of successful induction of resistance during the present investigation is comparatively low since the moderately resistant and moderately susceptible plants in the M2 were considered susceptible. The newness of resistance developed in the present study needs to be tested by going for allelic testing and testing against different pathotypes. Induced mutants have been used to develop new BB resistant gene(s) vix. Xa-nm(t) by Nakai et al (1990) and xa-19 by Taura et al (1991). The productive BB resistant lines developed here were grown in plant progeny methods by screening in every generation. Those advanced lines are under field trials and would be used to study the genetics of BB resistance in the future and the release of commercial cultivars for the farming community of this region

  5. Gamma-ray Burst Cosmology

    CERN Document Server

    Wang, F Y; Liang, E W

    2015-01-01

    Gamma-ray bursts (GRBs) are the most luminous electromagnetic explosions in the Universe, which emit up to $8.8\\times10^{54}$ erg isotropic equivalent energy in the hard X-ray band. The high luminosity makes them detectable out to the largest distances yet explored in the Universe. GRBs, as bright beacons in the deep Universe, would be the ideal tool to probe the properties of high-redshift universe: including the cosmic expansion and dark energy, star formation rate, the reionization epoch and the metal enrichment history of the Universe. In this article, we review the luminosity correlations of GRBs, and implications for constraining the cosmological parameters and dark energy. Observations show that the progenitors of long GRBs are massive stars. So it is expected that long GRBs are tracers of star formation rate. We also review the high-redshift star formation rate derived from GRBs, and implications for the cosmic reionization history. The afterglows of GRBs generally have broken power-law spectra, so it...

  6. AGATA - Advanced GAmma Tracking Array

    International Nuclear Information System (INIS)

    The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation γ-ray spectrometer. AGATA is based on the technique of γ-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a γ ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realisation of γ-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterisation of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximise its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer.

  7. Gamma-scintigraphy; La gammascintigraphie

    Energy Technology Data Exchange (ETDEWEB)

    Desgrez, H.A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1960-06-15

    Gamma-scintigraphy is a medical technique making it possible to fix the image of certain organs after the concentration in these of emitting radioactive products. It is already widely used in the case of the thyroid gland with iodine-132 by applying the isotope iodine 131. The study of the liver and gall bladder is carried out using colloidal gold 198 and Bengal pink marked with iodine 131. Serum albumin marked with iodine 131 makes it possible to study rachidian blockages. Other applications can already be foreseen in this direction. (author) [French] La gammascintigraphie est une technique medicale permettant de faire l'image de certains organes apres concentration dans ceux-ci de produits radioactifs emetteurs. Son utilisation deja repandue en ce qui concerne la thyroidine et l'iode-131 est possible avec l'iode-132 pour cette meme glande. Avec l'or colloidal 198 et le rose bengale marque a l'iode-131, on pratique des etudes du foie et de la vesicule biliaire. La serumalbumine marquee a l'iode-131 permet d'etudier les blocages rachidiens. D'autres possibilites sont des maintenant envisageables dans cette direction. (auteur)

  8. RID-41 gamma flaw detector

    International Nuclear Information System (INIS)

    The design is described and the main characteristics are given of a universal stationary hose-type gamma flow detector with a 60Co source from 3O to 4g0 Ci for high-productive control of thick-walled products from steel and other materials. The principal units of the instrument are a radiation head, a control panel, and a charge-exchange container. The flaw detector may be used both in shield chambers and in shop or mounting conditions on complying with due requirements of radiation protection. The high activity of the source at relatively small dimensions of its active part ensures good detection of defects. The high radioscopy rate permits to use the flaw detector in conditions of increased background radiation, e.g. during routine repairs and inspections at nuclear power plants. The instrument may also be used in radiometric complexes, and produces a considerable economic effect. This flaw-detector corresponds to ISO and IAEA requirements and may be delivered for export

  9. How to treat $\\gamma_5$

    CERN Document Server

    Cheng, H; Cheng, Hung

    1996-01-01

    In this paper, we present a method to perform renormalized perturbation calculations to gauge theories with chiral fermions. We find it proper to focus directly on the Ward-Takahashi identities, relegating dimensional regularization into a supplementary and secondary role. We show with the example of the Abelian-Higgs theory how to handle amplitudes involving fermions, particularly how to handle the matrix $\\gamma_5$. As a demonstration of our method of renormalization, we evaluate the radiative corrections of the triangular anomaly in the Abelian-Higgs theory with chiral fermions and with Yukawa couplings. Families of chiral fermions with appropriate quantum numbers are introduced so that the sum of their contributions to the lowest-order anomaly is equal to zero. Both the left-handed and right-handed fermion of this theory are assumed to interact with the gauge field. We find that the anomaly amplitude in the next-lowest order is not zero, contrary to common belief. This anomaly amplitude is calculated with...

  10. Gamma-ray detected radio galaxies

    Science.gov (United States)

    Beckmann, Volker; Soldi, Simona; De Jong, Sandra; Kretschmer, Karsten; Savchenko, Volodymyr

    2016-07-01

    So far 15 radio galaxies have been detected in the gamma-ray domain by CGRO/EGRET and Fermi/LAT, with a few detections also in the VHE range. We search for distinguishing parameters and estimate the total number of gamma-ray emitting radio galaxies that are potentially detectable by Fermi/LAT. We use Fermi/LAT data in comparison with X-ray and hard X-ray data in order to constrain basic parameters such as the total power of the inverse Compton branch and the position of its peak. We search for possible correlations between the radio, UV, X-ray, and gamma-ray domain and derive the number counts distribution. We then compare their properties with those of the radio galaxies in the 3CRR and SMS4 catalogues. The data show no correlation between the peak of the inverse Compton emission and its luminosity. For the gamma-ray detected radio galaxies the luminosities in the various bands are correlated, except for the UV band, but there is no indication of a correlation of peak frequency or luminosity with the spectral slopes in the X-ray or gamma-ray band. The comparison with other bright radio galaxies shows that the gamma-ray detected objects are among those that have the largest X-ray but rather moderate radio fluxes. Their UV and X-ray luminosities are similar, but gamma-ray detected radio galaxies are predominantly of type FR-I, while the 3CRR sample contains mainly FR-II objects. The number counts of the so far gamma-ray detected radio galaxies shows a very shallow slope, indicating that potentially a fraction of radio galaxies has been missed so far or has not been identified as such, although the predicted number of 22 ± 7 is consistent with the observed 15 objects.

  11. Latest Results from VERITAS: Gamma 2016

    CERN Document Server

    Holder, J

    2016-01-01

    The VERITAS imaging atmospheric Cherenkov telescope array has been observing the northern TeV sky with four telescopes since summer 2007. Over 50 gamma-ray sources have been studied, including active and starburst galaxies, pulsars and their nebulae, supernova remnants and Galactic binary systems. We review here some of the most recent VERITAS results, and discuss the status and prospects for collaborative work with other gamma-ray instruments, and with multimessenger observatories.

  12. Ballerina - pirouettes in search of gamma bursts

    DEFF Research Database (Denmark)

    Brandt, Søren Kristian; Lund, Niels; Pedersen, Henrik; Hjorth, J.

    1999-01-01

    The cosmological origin of gamma ray bursts has now been established with reasonable certainty, Many more bursts will need to be studied to establish the typical distance scale, and to map out the large diversity in properties which have been indicated by the first handful of events. We are...... proposing Ballerina, a small satellite to provide accurate positions and new data on the gamma-ray bursts. We anticipate a detection rate an order of magnitude larger than obtained from Beppo-SAX....

  13. Supernovae and gamma-ray bursts connection

    Energy Technology Data Exchange (ETDEWEB)

    Valle, Massimo Della [INAF-Napoli, Capodimonte Observatory, Salita Moiariello, 16, I-80131 Napoli (Italy); International Center for Relativistic Astrophysics Network, Piazzale della Repubblica 10, I-65122, Pescara (Italy)

    2015-12-17

    I’ll review the status of the Supernova/Gamma-Ray Burst connection. Several pieces of evidence suggest that long duration Gamma-ray Bursts are associated with bright SNe-Ic. However recent works suggest that GRBs might be produced in tight binary systems composed of a massive carbon-oxygen cores and a neutron star companion. Current estimates of the SN and GRB rates yield a ratio GRB/SNe-Ibc in the range ∼ 0.4% − 3%.

  14. Gamma Radiosensitivity Study on Chili (Capsicum annuum)

    OpenAIRE

    Shairul R.  Omar; Osumanu H.   Ahmed; Shaharudin Saamin; Nik M.A.  Majid

    2008-01-01

    Induced mutation by gamma irradiation has been found to be a very useful technique for crop improvement. Apart from this, the proper use of induced mutation in plant breeding has become a profitable approach. This investigation was carried out to determine the LD50 and effect of gamma rays on germination, plant height, survival percentage, root length, root dry weight and shoot dry weight of seedlings derived from irradiated seeds of chili (Capsicum annuum). Seeds of chili were treated ...

  15. Electromagnetically induced transparency for single gamma photons.

    OpenAIRE

    Gheysen, Stijn

    2006-01-01

    Elektromagnetisch geïnduceerde transparantie voor een gamma foton. In dit onderzoek bestuderen we de mogelijke implementatie van elektromagnetisch geïnduceerde transparantie (EIT) voor gamma fotonen in een nucleair systeem. EIT is een goed gekend fenomeen in de kwantumoptica, waar het geobserveerd wordt als een transparant venster in de resonante absorptie van elektromagnetische straling in een drie-niveau Λ-schema. Het onderliggend fysisch principe is gebaseerd op coherente populatie ...

  16. Scope of commercial gamma sterilization in Pakistan

    International Nuclear Information System (INIS)

    Usefulness of gamma sterilization has been demonstrated to the Pakistani manufactureres by irradiating (to 2.5 Megarads) different articles namely: surgical gloves, catgut sutures, phials, transfusion sets, catheters, medicines like betamethasone etc., using a gamma source at PINSTECH on a limited scale. Attempts to develop some colour-change dosimeters from various dyes/polymer systems for possible use in a commercial irradiator are briefly described. (authors)

  17. Supernovae and gamma-ray bursts connection

    Science.gov (United States)

    Valle, Massimo Della

    2015-12-01

    I'll review the status of the Supernova/Gamma-Ray Burst connection. Several pieces of evidence suggest that long duration Gamma-ray Bursts are associated with bright SNe-Ic. However recent works suggest that GRBs might be produced in tight binary systems composed of a massive carbon-oxygen cores and a neutron star companion. Current estimates of the SN and GRB rates yield a ratio GRB/SNe-Ibc in the range ˜ 0.4% - 3%.

  18. New type air (automobile) gamma spectroscopic system

    International Nuclear Information System (INIS)

    A new type air (automobile) gamma spectroscopic system for identification and measuring of contamination with natural and artificial gamma isotopes is described. developed. Its main principle is a maximal use of the energy resolution of NaJ(Tl) detectors. The system consists of a spectrometer working simultaneously with a set of 1-16 scintillator blocks and a registration/ data processing unit. The operational mode, optimal performance and control subsystem are described

  19. Gamma Oscillations Distinguish True From False Memories

    OpenAIRE

    Sederberg, Per B.; Schulze-Bonhage, Andreas; Madsen, Joseph R.; Bromfield, Edward B.; Litt, Brian; Brandt, Armin; Kahana, Michael J.

    2007-01-01

    To test whether distinct patterns of electrophysiological activity prior to a response can distinguish true from false memories, we analyzed intracranial electroencephalographic recordings while 52 patients undergoing treatment for epilepsy performed a verbal free-recall task. These analyses revealed that the same pattern of gamma-band (28–100 Hz) oscillatory activity that predicts successful memory formation at item encoding—increased gamma power in the hippocampus, prefrontal cortex, and le...

  20. Two-gluon exchange contribution to elastic $\\gamma \\gamma \\to \\gamma \\gamma$ scattering and production of two-photons in ultraperipheral ultrarelativistic heavy ion and proton-proton collisions

    CERN Document Server

    Klusek-Gawenda, Mariola; Szczurek, Antoni

    2016-01-01

    We discuss the two-gluon exchange contribution (formally three-loops) to elastic photon-photon scattering in the high-energy approximation. The elastic $\\gamma\\gamma \\to \\gamma \\gamma$ amplitude is given in the impact-factor representation for all helicity configurations and finite quark masses. We discuss the importance of including the charm quark, which contribution, due to interference, can enhance the cross section considerably. We investigate the contribution to the $\\gamma \\gamma \\to \\gamma \\gamma$ amplitude from the soft region, by studying its dependence on nonperturbative gluon mass. Helicity-flip contributions are shown to be much smaller than helicity-conserving ones. We identify region(s) of phase space where the two-gluon exchange contribution becomes important ingredient compared to box and nonperturbative VDM-Regge mechanisms considered in the literature. Consequences for the $A A \\to A A \\gamma \\gamma$ reaction are discussed. Several differential distributions are shown. A feasibility study t...

  1. Measurements of the $pp\\to\\mathrm{W}^{\\pm}\\gamma\\gamma$ and $pp\\to\\mathrm{Z}\\gamma\\gamma$ cross sections and Limits on Dimension-8 Effective Anomalous Gauge Couplings at $\\sqrt{s} = 8~\\mathrm{TeV}$

    CERN Document Server

    CMS Collaboration

    2016-01-01

    We present measurements of the cross sections of the $pp\\to\\,$W$^{\\pm}\\gamma\\gamma\\,$ and $pp\\to\\,$Z$\\gamma\\gamma\\,$ final states in the channels where the W boson decays to muons and Z boson decays to electrons or muons. The measurement uses $19.4~\\mathrm{fb}^{-1}$ of $8$ TeV data collected with the CMS experiment in 2012. We observe the signal for W$^{\\pm}\\gamma\\gamma\\,$ with a significance of $2.4 \\sigma$ and we observe the Z$\\gamma\\gamma\\,$ signal with a significance of $5.9 \\sigma$. Upper limits are placed on anomalous quartic gauge couplings using the W$^{\\pm}\\gamma\\gamma$ final state, with particular sensitivity to the $f_{\\mathrm{T}, 0}$ coupling. The observed $95\\%$ confidence level limit on the $f_{\\mathrm{T}, 0}$ coupling is $-37.5 < \\frac{f_{\\mathrm{T}, 0}}{\\Lambda^4} < 38.1$.

  2. Gamma, x-ray reduction system. Volume I: gamma

    International Nuclear Information System (INIS)

    The starting premises for this data reduction system were (a) the individual researcher needs all the accuracy that can be achieved but he has neither the time nor the inclination to learn how to achieve it, and (b) if the data reduction system is to be centralized the people operating it will want to minimize conversation with the computer. This is a working system. All spectral data are stored on Data General 4234 discs after background normalization and strip. Storage is initiated from magnetic tapes loaded by detached pulse height analyzers or directly from Scorpio pulse height analyzers. The only restrictions placed on the individual researchers are that the pulse height analyzer energy scale be set up consistently, that a recovery standard be run at least once every day of use, and the total acquisition system be calibrated to its range of use. In many instances, and if desirable, the latter is provided as a service. At the time of writing this gamma data reduction system is actively being used to calculate net peak areas, activities with or without time correction, activations analysis results, counting precisions, and dynamic limits of detection for the spectral data output of 17 detached pulse height analyzers. To all modes of data reduction are applied background subtraction, random summing correction, detector recovery factor correction, peak interfernce correction (second-order product interference for activation analysis), geometry function correction, acquisition time decay corrections, external and internal sorber correction. All of this is accomplished and a customer report typed in a readable format after a halfline of noninteractive instruction

  3. Cosmic gamma-ray studies at Srinagar

    International Nuclear Information System (INIS)

    Cosmic gamma ray studies being carried out at the Nuclear Research Laboratory at Srinagar and Gulmarg are described and some of the results of observation and possible conclusions are mentioned. These studies use ground base techniques which can detect short-time scale gamma ray bursts from supernovae and primordial black hole (PBH) and also high energy gamma rays from various point sources. A large area photomultiplier system is employed to detect pulses of visible fluorescence radiation which is caused by a gamma ray burst of supernovae of PBH origin. However, any signal out a large number of signals recorded at Gulmarg could not be identified as coinciding with any such event observed elsewhere. It shows that the size of the burst source cannot exceed 30 km., which is in agreement with neutron-star source models. An array using plastic scintillator detectors at the corner of a 10 metre square has been set up at Gulmarg to detect air-shower due to high energy gamma rays. Cerenkov light pulses recorded at Gulmarg have been projected on the sidereal map. A significant excess observed in the right ascension range 20 +- 3 h suggests the possible presence of a quasic-periodic source of gamma rays of energy greater than 1014 eV in the general direction of Cygnus X-3. Future programme of studies is mentioned. (K.M.)

  4. Gamma-ray Albedo of the Moon

    Energy Technology Data Exchange (ETDEWEB)

    Moskalenko, Igor V.; Porter, Troy A.

    2007-06-14

    We use the GEANT4 Monte Carlo framework to calculate the gamma-ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees with the EGRET data. We show that the spectrum of gamma-rays from the Moon is very steep with an effective cutoff around 3 GeV (600 MeV for the inner part of the Moon disc). Since it is the only (almost) black spot in the gamma-ray sky, it provides a unique opportunity for calibration of gamma-ray telescopes, such as the forthcoming Gamma Ray Large Area Space Telescope (GLAST). The albedo flux depends on the incident CR spectrum which changes over the solar cycle. Therefore, it is possible to monitor the CR spectrum using the albedo gamma-ray flux. Simultaneous measurements of CR proton and helium spectra by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA), and observations of the albedo -rays by the GLAST Large Area Telescope (LAT), can be used to test the model predictions and will enable the GLAST LAT to monitor the CR spectrum near the Earth beyond the lifetime of PAMELA.

  5. Gamma irradiation of peanut (Arachis hypogaea L.)

    International Nuclear Information System (INIS)

    This study was conducted to determine some effects of gamma radiation on peanut (Arachis hypogaea L.). The biological parameters used to evaluate these effects were: % emergence of irradiated seeds, % survival of plants, growth rate, chlorophyll mutations, morphological changes and yield potential. Seeds were irradiated with dose levels of 2.5, 5, 10, 15, 20, 25, 30 and 40 KK per hour of gamma radiation from a Co-60 source. In general, % of emergence and survival in the M1 gene ration decreased with increasing doses of gamma radiation. Morphological changes induced by gamma radiation in the M1 generation of peanut were: leaf flecks, thickened leaves, red purple seeds and red colored seed coat. Generally, frequency of these morphological changes increased with increasing doses of gamma radiation. Protein and fat contents were increased by 2.8% to 1.5% respectively, while starch content decreased with 2.6% in the M2. On the basis of the results obtained, gamma radiation is an effective mutagenic agent in inducing various morphological and genetic changes in peanut

  6. Gamma rays from extragalactic astrophysical sources

    CERN Document Server

    Bosch-Ramon, V

    2011-01-01

    Presently there are several classes of detected gamma-ray extragalatic sources. They are mostly associated to active galactic nuclei (AGN) and (at soft gamma rays) to gamma-ray bursts (GRB), but not only. Active galactic nuclei consist of accreting supermassive black holes hosted by a galaxy that present in some cases powerful relativistic jet activity. These sources, which have been studied in gamma rays for several decades, are probably the most energetic astrophysical objects, and their appearance depends much on whether their jets point to us. Gamma-ray bursts, thought to be associated to collapsing or merging stellar-mass objects at cosmological distances, are also accreting highly relativistic jet sources that shine strongly at high energies. These are very short-duration events, but they are also the most luminous. Recently, star formation galaxies have turned out to be also gamma-ray emitters. On the other hand, clusters of galaxies have not been detected beyond X-rays yet. These are the largest known...

  7. Gamma-Ray Bursts: The End Game

    Science.gov (United States)

    Lamb, Don

    1997-11-01

    The nature of gamma-ray bursts has been one of the greatest unsolved mysteries in astrophysics for more than a quarter century. A major reason for this is that no definite counterparts to the bursts could be found at other wavelengths, despite intense efforts spanning more than two decades. Consequently, the study of gamma-ray bursts has been isolated from the rest of astronomy. Scientists studying them have had only the laws of physics and the bursts themselves to guide them in attempting to solve the burst mystery. All of this changed dramatically with the discovery earlier this year of fading X-ray and optical sources in the arcminute-sized positional error boxes of several gamma-ray bursts. For the first time, temporal, as well as spatial, coincidence could be used to associate these X-ray and optical sources with the gamma-ray bursts. As a result, the odds are great that the fading X-ray and optical sources are counterparts of the bursts, and that the study of gamma-ray bursts has finally been connected with the rest of astronomy. In this talk, we describe the dramatic new information about the nature of gamma-ray bursts that the X-ray, optical, and radio observations of the fading sources have provided, and emphasize the implications that this information has for the distance scale to the bursts.

  8. Gamma-ray pulsar studies with COMPTEL

    Science.gov (United States)

    Hermsen, W.; Kuiper, L.; Diehl, R.; Lichti, G.; Schoenfelder, V.; Strong, A. W.; Connors, A.; Ryan, J.; Bennett, K.; Busetta, M.; Carraminana, A.; Buccheri, R.; Grenier, I. A.

    1994-06-01

    Since the launch of the Compton Gamma-Ray Observatory (CGRO) the number of detected gamma-ray pulsars increased from two to six. COMPTEL, on-board CGRO and sensitive to gamma-rays with energies between approximately 0.7 and 30 MeV, detected three of these unambiguously. The classical Crab and Vela pulsars have been observed on several occasions and detailed pulse patterns and spectral parameters have been derived. The new CGRO gamma-ray pulsar PSR B1509-58 has been detected by COMPTEL at a significance level above 4 sigma, consistently in a timing and spatial analysis. A likely detection of Geminga has been obtained at an approximately 3 sigma level. This indication is found in a phase interval in which COS B data showed the presence of a new variable component, Interpeak 2, exhibiting a very soft spectrum above 50 MeV. The diversities in light-curve sphapes and spectral distributions, the apparent time variabilities, and the significant differences in the fractions of the spin-down power radiated at gamma-ray energies in this small sample of gamma-ray pulsars pose important constraints to pulsar modeling.

  9. Collagen I confers gamma radiation resistance

    International Nuclear Information System (INIS)

    The effect of collagen on the response of somatomammotroph tumor cells (GH3) to gamma, radiation therapy was studied in vitro. After incubating confluent GH3 cell monolayers in a serum-free, maintaining medium, either with or without collagen, the monolayers were irradiated with 137Cs, gamma radiation. Collagen reduces cell mortality via ERK1/2 activation, abolishing gamma radiation, cell death, and promotes cell invasion when acting in synergy with collagen and in association with the, MAPK/ERK1/2 signaling pathway activation. The presence of collagen in somatomammotroph tumors, confers resistance to radiation. - Highlights: ► Collagen effect on GH3 cells response to gamma radiation therapy was studied. ► Collagen ERK activation abolishes gamma radiation GH3 cell death. ► Gamma radiation promotes cell invasion and ERK activation in synergy with collagen. ► The presence of collagen in somatomammotroph tumors confers radiotherapy resistance. ► Analysis of tumor surrounding tissue before applying radiotherapy would be advisable.

  10. A Tight $L_{\\rm p, iso}-E'_{\\rm p}-\\Gamma_0$ Correlation of Gamma-Ray Bursts

    CERN Document Server

    Liang, En-Wei; LV, Jing; Lu, Ruijing; Zhang, Jin; Zhang, Bing

    2015-01-01

    We select a sample of 34 gamma-ray bursts (GRBs) whose $\\Gamma_0$ values are derived with the onset peak observed in the afterglow lightcurves (except for GRB 060218 whose $\\Gamma_0$ is estimated with its radio data), and investigate the correlations among $\\Gamma_0$, the isotropic peak luminosity ($L_{\\rm p, iso}$), and the peak energy of the $\

  11. Recombinant mouse interferon-gamma regulation of antibody production.

    OpenAIRE

    Johnson, H M; Torres, B A

    1983-01-01

    Interferon-gamma produced in monkey cells by transfection with mouse interferon-gamma cDNA suppressed the mouse in vitro antibody response in a manner similar to that of natural mouse interferon-gamma. Significant suppression was obtained with as little as 1 U of interferon. Recombinant human interferon-gamma produced by cloning in a similar fashion was not suppressive. Both the suppressive and the antiviral activities of recombinant interferon-gamma were neutralized by antibodies to mouse na...

  12. Search for Charmonium States Decaying to J/psi gamma gamma Using Initial-State Radiation Events

    CERN Document Server

    Aubert, B; Bóna, M; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Del Amo-Sánchez, P; Barrett, M; Ford, K E; Hart, A J; Harrison, T J; Hawkes, C M; Morgan, S E; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schröder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, Y K; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Wren, A C; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Stängle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, Gallieno; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Regensburger, J J; Ter-Antonian, R; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; La Vaissière, C de; Hamon, O; Hartfiel, B L; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai-Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martínez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R V; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihályi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H; al, et

    2006-01-01

    We study the processes e+e- -> (J/psi gamma gamma) gamma and e+e- -> (J/psi pi- pi+) gamma where the hard photon radiated from an initial e+e- collision with center-of-mass (CM) energy near 10.58 GeV is detected. In the final state J/psi gamma gamma we consider J/psi pi0, J/psi eta, chi_{c1} gamma, and chi_{c2} gamma candidates. The invariant mass of the hadronic final state defines the effective e+e- CM energy in each event, so these data can be compared with direct e+e- measurements. We report 90% CL upper limits for the integrated cross section times branching fractions of the J/psi gamma gamma channels in the Y(4260) mass region.

  13. Xa因子抑制剂与华法林对房颤患者抗凝疗效的比较--Meta分析与系统性评价%Meta Analysis and System Review on Comparison of Factor Xa Inhibitors and Warfarin on the Anticoagulation Effect in Patient with Artrial Fibrillation

    Institute of Scientific and Technical Information of China (English)

    刘入源; 郭凤; 阿尔达克

    2015-01-01

    目的:系统性评价口服Xa抑制剂和华法林用于房颤患者抗凝治疗的有效性和安全性。方法按照Cochrane系统评价制作方法,计算机检索Pub Med数据库、Ovid数据库、EMBASE数据库、Medline光盘数据库、同方数据库检索相关文献,查找网络上有关的所有文章及未发表的病例对照实验,并用手工检索等方法收集相关文献,并对所有文献的参考文献进行进一步的检索。收集所有相关的病例对照试验,采用Cochrane协作网提供的RevMan5.0软件进行Meta分析,以获得口服Xa抑制剂和华法林相比对房颤患者抗凝效果的有效性和安全性的相关证据。结果 Xa抑制剂与华法林相比,能明显降低总死亡率【P=0.01,优势比(OR)0.89,95%可信区间(CI)(0.82,0.98)】、出血性脑卒中发生率【P<0.00001,优势(OR)0.49,95%可信区间(CI)(0.39,0.60)】、主要部位出血发生率【P=0.07,优势比(OR)0.76,95%可信区间(CI)(0.57,1.02)】;然而缺血性脑卒中发生率【P=0.18,优势比(OR)1.08,95%可信区间(CI)(0.97,1.20)】、心肌梗死发生率【P=0.19,优势比(OR)0.94,95%可信区间(CI)(0.82,1.08)】、消化道出血发生率【P=0.65,优势比(OR)1.07,95%可信区间(CI)(0.78,1.47)】无差别。结论新型口服抗凝剂利伐沙班、阿哌沙班、依度沙班的最大优势在于出血风险减少和用药方便,但目前此类药物临床使用时间过短和上市后可能昂贵的价格,同时缺乏明确的解救药物,尚不足以将这些药物作为一线用药考虑。%Objective To evaluation system of oral factor Xa inhibitor and warfarin for the effectiveness and safety of anticoagulation in patients with atrial fibrillation treatment. Methods the method of making Cochrane system in accordance with the evaluation, Pub Med database, Ovid database, EMBASE data base, Medline CD

  14. Gravitational Gamma Spectrometer for Studying the Gamma Resonance of the Long-Lived Isomer 103mRh

    CERN Document Server

    Davydov, A V; Kalantarov, V D; Korotkov, M M; Migachev, V V; Novozhilov, Yu B; Stepanov, A M

    2015-01-01

    The principle of operation and the construction are described of the gravitational gamma spectrometer to study the gamma resonance of the long-lived isomer $^{103m}$Rh. This is a table-top device which measures the form of gamma resonance by the dependence of counting rate of gamma-rays in collimated beams on the angle of their inclination with respect of the horizontal plane. Methods of fabrication of gamma-sources for this device are considered.

  15. A Search for Gamma-Ray Bursts and Pulsars, and the Application of Kalman Filters to Gamma-Ray Reconstruction

    OpenAIRE

    Jones, B B

    2002-01-01

    Part I describes the analysis of periodic and transient signals in EGRET data. A method to search for the transient flux from gamma-ray bursts independent of triggers from other gamma-ray instruments is developed. Several known gamma-ray bursts were independently detected, and there is evidence for a previously unknown gamma-ray burst candidate. Statistical methods using maximum likelihood and Bayesian inference are developed and implemented to extract periodic signals from gamma-ray sources ...

  16. Polarization effects and gamma transport

    International Nuclear Information System (INIS)

    The scattering processes Rayleigh and Compton, so important in X- and gamma-ray spectrometry, have both strong dependencies on the polarization state of the incident and scattered photons. Thus, are rare the experiments of scattering that not need to make explicit reference to the polarization state to the photons before and after the collision. It is well known also, that these scattering processes produce, besides of the corresponding peaks Rayleigh and Compton, a prevailing part of the continuous background found in X-ray spectra and much of the enhancement modifying the shape and the intensity of the characteristic lines. Therefore, it is easily noted that the polarization state of the radiation can be used to control the extent of the scattering contributions in X-ray spectra, as it was pointed out in a previous work. This article discusses some interesting properties regarding the transport of polarized photons in homogenous media, described with recourse to the Boltzmann transport equation and stokes representation of polarization. These properties can help to understand how the polarization of the source can be used to reduce the influence of scattering peak. The effects of the three types of polarized sources used in X-ray spectrometry, unpolarized, linearly polarized and circularly polarized, are analyzed separately stressing the suggested applications in each case. The effect of an external magnetic field on the cross section of magnetic (Compton) scattering is also discussed. It is shown that the effect of the magnetic field can be sensed and studied with a X-ray spectrum by using a circularly (or elliptically) polarized source. 10 figs., 1 tab., 106 refs. (author)

  17. Measurement of $\\Gamma(\\eta \\to \\pi^+\\pi^-\\gamma)/\\Gamma(\\eta \\to \\pi^+\\pi^-\\pi^0)$ with KLOE experiment

    CERN Document Server

    Ambrosino, F; Antonelli, M; Archilli, F; Balwierz, I; Bencivenni, G; Bini, C; Bloise, C; Bocchetta, S; Bossi, F; Branchini, P; Capon, G; Capussela, T; Ceradini, F; Ciambrone, P; Czerwiski, E; De Lucia, E; De Santis, A; De Simone, P; De Zorzi, G; Denig, A; Di Domenico, A; Di Donato, C; Di Micco, B; Dreucci, M; Felici, G; Fiore, S; Franzini, P; Gatti, C; Gauzzi, P; Giovannella, S; Graziani, E; Jacewicz, M; Lee-Franzini, J; Martemianov, M; Martini, M; Massarotti, P; Meola, S; Miscetti, S; Morello, G; Moulson, M; Muller, S; Napolitano, M; Nguyen, F; Palutan, M; Passeri, A; Patera, V; Longhi, I Prado; Santangelo, P; Sciascia, B; Silarski, M; Spadaro, T; Taccini, C; Tortora, L; Venanzoni, G; Versaci, R; Xu, G; Zdebik, J; Badoni, D; Bocci, V; Budano, A; Bulychjev, S A; Campana, P; Dané, E; De Robertis, G; Domenici, D; Erriquez, O; Fanizzi, G; Gonnella, F; Happacher, F; Höistad, B; Iarocci, E; Johansson, T; Kulikov, V; Kupsc, A; Loddo, F; Matsyuk, M; Messi, R; Moricciani, D; Moskal, P; Ranieri, A; Sarra, I; Schioppa, M; Sciubba, A; Wiślicki, W; Wolke, M

    2011-01-01

    We report the measurement of the ratio $\\Gamma(\\eta \\to \\pi^+\\pi^-\\gamma)/\\Gamma(\\eta \\to \\pi^+\\pi^-\\pi^0)$ analyzing a large sample of $\\phi \\to \\eta \\gamma$ decays recorded with the KLOE experiment at the DA$\\Phi$NE $e^+ e^-$ collider, corresponding to an integrated luminosity of 558 pb$^{-1}$. The $\\eta \\to \\pi^+\\pi^-\\gamma$ process is supposed to proceed both via a resonant contribution, mediated by the $\\rho$ meson, and a non resonant direct term, connected to the box anomaly. The presence of the direct term affects the partial width value. Our result $R_{\\eta}=\\Gamma(\\eta \\to \\pi^+ \\pi^- \\gamma)/\\Gamma(\\eta \\to \\pi^+ \\pi^- \\pi^0)= 0.1838\\pm 0.0005_{stat} \\pm 0.0030_{syst}$ is in agreement with a recent CLEO measurement, which differs by more 3 $\\sigma$ from the average of previous results.

  18. Measuring anomalous WW$\\gamma$ and t$\\bar{\\text{t}}\\gamma$ couplings using top+$\\gamma$ production at the LHC

    CERN Document Server

    Etesami, Seyed Mohsen; Najafabadi, Mojtaba Mohammadi

    2016-01-01

    We consider the electroweak production of a top quark in association with a photon at the LHC to probe the electroweak top quark couplings (t$\\bar{\\text{t}}\\gamma$) as well as the triple gauge boson couplings (WW$\\gamma$). The study is based on the modifications of the t$\\bar{\\text{t}}\\gamma$ and WW$\\gamma$ interactions via heavy degrees of freedom in the form of dimension-six operators which we add to the standard model Lagrangian. A binned angular asymmetry in single top quark plus photon events and cross section ratio are proposed to probe the anomalous t$\\bar{\\text{t}}\\gamma$ and WW$\\gamma$ couplings. It is shown that the proposed angular asymmetry can distinguish anomalous t$\\bar{\\text{t}}\\gamma$, WW$\\gamma$ couplings from the standard model prediction and yield a great sensitivity.

  19. On the equation $p \\frac{\\Gamma(\\frac{n}{2}-\\frac{s}{p-1})\\Gamma(s+\\frac{s}{p-1})}{\\Gamma(\\frac{s}{p-1})\\Gamma(\\frac{n-2s}{2}-\\frac{s}{p-1})} =\\frac{\\Gamma(\\frac{n+2s}{4})^2}{\\Gamma(\\frac{n-2s}{4})^2}$

    OpenAIRE

    Luo, Senping; Wei, Juncheng; Zou, Wenming

    2016-01-01

    The note is aimed at giving a complete characterization of the following equation: $$\\displaystyle p\\frac{\\Gamma(\\frac{n}{2}-\\frac{s}{p-1})\\Gamma(s+\\frac{s}{p-1})}{\\Gamma(\\frac{s}{p-1})\\Gamma(\\frac{n-2s}{2}-\\frac{s}{p-1})} =\\frac{\\Gamma(\\frac{n+2s}{4})^2}{\\Gamma(\\frac{n-2s}{4})^2}.$$ The method is based on some key transformation and the properties of the Gamma function. Applications to fractional nonlinear Lane-Emden equations will be given.

  20. Development of a Second Generation Bovigam Interferon Gamma (IFN-gamma) Assay

    Science.gov (United States)

    In search for better tools to control bovine tuberculosis, the development of diagnostic tests with improved performance and enhanced ease-of-use has a high priority. BOVIGAM®, a rapid laboratory assay, measures gamma interferon (IFN-gamma) production in whole blood samples after induction of a ce...

  1. Measurement of gamma gamma* --> pi0 transition form factor at Belle

    OpenAIRE

    The Belle Collaboration; Uehara, S.; Watanabe, Y.; Nakazawa, H; Adachi, I.; Aihara, H.; Asner, D. M.; Aushev, T.; Bakich, A. M.; Belous, K.; Bhardwaj, V.; Bhuyan, B.; Bischofberger, M.; Bondar, A.; Bonvicini, G.

    2012-01-01

    We report a measurement of the process gamma gamma* --> pi0 with a 759 fb^{-1} data sample recorded with the Belle detector at the KEKB asymmetric-energy e+e- collider. The pion transition form factor, F(Q^2), is measured for the kinematical region 4 GeV^2

  2. Higgs, SUSY and the Standard Model at $\\gamma\\gamma$ Colliders

    CERN Document Server

    Hagiwara, K

    2001-01-01

    In this report I surveyed physics potential of the gamma-gamma option of a Linear e+e- Collider with the following questions in mind: What new discovery can be expected at a gamma-gamma collider in addition to what will be learned at its `parent' e+e- Linear Collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e- beams, we find that a gamma-gamma collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e-e- system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a gamma-gamma collider. CP property of the scalar sector can be explored in detail by making use of linear polarization of the colliding photons, decay angular correlations of final state particles, and the pattern of ...

  3. Gravitational Light Bending Prevents $\\gamma\\gamma$ Absorption in Gravitational Lenses

    CERN Document Server

    Boettcher, Markus

    2016-01-01

    The magnification effect due to gravitational lensing enhances the chances of detecting moderate-redshift ($z \\sim 1$) sources in very-high-energy (VHE; $E > 100$ GeV) $\\gamma$-rays by ground-based Atmospheric Cherenkov Telescope facilities. It has been shown in previous work that this prospect is not hampered by potential $\\gamma-\\gamma$ absorption effects by the intervening (lensing) galaxy, nor by any individual star within the intervening galaxy. In this paper, we expand this study to simulate the light-bending effect of a realistic ensemble of stars. We first demonstrate that, for realistic parameters of the galaxy's star field, it is extremely unlikely (probability $\\lesssim 10^{-6}$) that the direct line of sight between the $\\gamma$-ray source and the observer passes by any star in the field close enough to be subject to significant $\\gamma\\gamma$ absorption. Our simulations then focus on the rare cases where $\\gamma\\gamma$ absorption by (at least) one individual star might be non-negligible. We show ...

  4. Perspectives of the GAMMA-400 space observatory for high-energy gamma rays and cosmic rays measurements

    Science.gov (United States)

    Topchiev, N. P.; Galper, A. M.; Bonvicini, V.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Bakaldin, A. V.; Bergstrom, L.; Berti, E.; Bigongiari, G.; Bobkov, S. G.; Boezio, M.; Bogomolov, E. A.; Bonechi, S.; Bongi, M.; Bottai, S.; Castellini, G.; Cattaneo, P. W.; Cumani, P.; Dalkarov, O. D.; Dedenko, G. L.; De Donato, C.; Dogiel, V. A.; Finetti, N.; Gorbunov, M. S.; Gusakov, Yu V.; Hnatyk, B. I.; Kadilin, V. V.; Kaplin, V. A.; Kaplun, A. A.; Kheymits, M. D.; Korepanov, V. E.; Larsson, J.; Leonov, A. A.; Loginov, V. A.; Longo, F.; Maestro, P.; Marrocchesi, P. S.; Men'shenin, A. L.; Mikhailov, V. V.; Mocchiutti, E.; Moiseev, A. A.; Mori, N.; Moskalenko, I. V.; Naumov, P. Yu; Papini, P.; Pearce, M.; Picozza, P.; Rappoldi, A.; Ricciarini, S.; Runtso, M. F.; Ryde, F.; Serdin, O. V.; Sparvoli, R.; Spillantini, P.; Stozhkov, Yu I.; Suchkov, S. I.; Taraskin, A. A.; Tavani, M.; Tiberio, A.; Tyurin, E. M.; Ulanov, M. V.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Yurkin, Yu T.; Zampa, N.; Zirakashvili, V. N.; Zverev, V. G.

    2016-02-01

    The GAMMA-400 gamma-ray telescope is intended to measure the fluxes of gamma-rays and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV. Such measurements concern the following scientific tasks: investigation of point sources of gamma-rays, studies of the energy spectra of Galactic and extragalactic diffuse emission, studies of gamma-ray bursts and gamma-ray emission from the Sun, as well as high precision measurements of spectra of high-energy electrons and positrons. Also the GAMMA- 400 instrument provides the possibility for protons and nuclei measurements up to knee. But the main goal for the GAMMA-400 mission is to perform a sensitive search for signatures of dark matter particles in high-energy gamma-ray emission. To fulfill these measurements the GAMMA-400 gamma-ray telescope possesses unique physical characteristics in comparison with previous and present experiments. The major advantage of the GAMMA-400 instrument is excellent angular and energy resolution for gamma-rays above 10 GeV. The GAMMA-400 experiment will be installed onboard of the Navigator space platform, manufactured by the NPO Lavochkin Association. The expected orbit will be a highly elliptical orbit (with apogee 300.000 km and perigee 500 km) with 7 days orbital period. An important profit of such an orbit is the fact that the full sky coverage will always be available for gamma ray astronomy.

  5. New insights from cosmic gamma rays

    Science.gov (United States)

    Roland, Diehl

    2016-04-01

    The measurement of gamma rays from cosmic sources at ~MeV energies is one of the key tools for nuclear astrophysics, in its study of nuclear reactions and their impacts on objects and phenomena throughout the universe. Gamma rays trace nuclear processes most directly, as they originate from nuclear transitions following radioactive decays or high-energy collisions with excitation of nuclei. Additionally, the unique gamma-ray signature from the annihilation of positrons falls into this astronomical window and is discussed here: Cosmic positrons are often produced from β-decays, thus also of nuclear physics origins. The nuclear reactions leading to radioactive isotopes occur inside stars and stellar explosions, which therefore constitute the main objects of such studies. In recent years, both thermonuclear and core-collapse supernova radioactivities have been measured though 56Ni, 56Co, and 44Ti lines, and a beginning has thus been made to complement conventional supernova observations with such measurements of the prime energy sources of supernova light created in their deep interiors. The diffuse radioactive afterglow of massive-star nucleosynthesis in gamma rays is now being exploited towards astrophysical studies on how massive stars feed back their energy and ejecta into interstellar gas, as part of the cosmic cycle of matter through generations of stars enriching the interstellar gas and stars with metals. Large interstellar cavities and superbubbles have been recognised to be the dominating structures where new massive-star ejecta are injected, from 26Al gamma-ray spectroscopy. Also, constraints on the complex interiors of stars derive from the ratio of 60Fe/26Al gamma rays. Finally, the puzzling bulge-dominated intensity distribution of positron annihilation gamma rays is measured in greater detail, but still not understood; a recent microquasar flare provided evidence that such objects may be prime sources for positrons in interstellar space, rather than

  6. Environmental monitoring and in situ gamma spectrometry

    International Nuclear Information System (INIS)

    The in-situ gamma ray spectrometry is widely used for monitoring of the natural as well as man-made radionuclides and corresponding gamma fields in the environment or working places. It finds effective application in the operational and accidental monitoring of the nuclear facilities and their vicinity, radioactive contamination measurements, environmental, radiation hygiene and radiation safety studies, etc. Knowledge of the used detection system response function/matrix makes it possible to analyze measured gamma fields characteristics, calculate energy distributions of the dosimetric quantities in these fields and/or calculate the concentrations of radionuclides in the environment (usually in the soil surface layer). Method of the gamma spectrometry data processing, based on the detector response knowledge, can be applied as for scintillation or semiconductor detection systems and ground measurements, as for airborne spectrometry monitoring. Methods for calculation of angular-energy distributions of gamma fields, originated from typical sources (using Monte Carlo simulation) are discussed as well as methods for calculation of detection systems responses and/or response matrixes in such gamma fields. Techniques of the measured spectra deconvolution and calculation of the dosimetric quantities energy distributions are overviewed. Method and results of calculations of the conversion factors for radionuclides concentrations determination from the measured and calculated photon fluencies energy distributions are discussed (including possibility to set a user-defined radionuclide depth distribution for given experimental data processing). Method (based on detection system response matrix Monte Carlo calculation) developed for the processing and analyzing data from airborne spectrometry monitoring and mapping is described. Sensitivity, achievable precision and some factors influencing the interpretation of results and their accuracy using considered methods are

  7. Determining gamma dose rates by field gamma spectroscopy in sedimentary media: Results of Monte Carlo simulations

    International Nuclear Information System (INIS)

    Field gamma spectrometers are widely used to determine gamma dose rates in sedimentary media. However the most widely used technique-the 'window technique'-is time consuming and introduces important statistical uncertainty in the determination of the radioelement contents, and finally on the gamma dose rate. The threshold technique directly relates the number of counts recorded above certain threshold energy to the gamma dose rate. Recently new experimental measurements further investigated this technique but it has not been tested in various sedimentary media. In this paper, numerical simulations using a specifically designed Geant4 code allow to test the sensitivity of this technique to changes of sediments nature, humidity content and disequilibrium in the U-series. Finally another threshold technique, relating the gamma dose rate to the energy per unit time deposited above another threshold energy, is investigated. It is shown than the latter has a number of advantages compared to the classical techniques. Experimental results testing this approach are presented.

  8. Gamma-Ray Lenses for Astrophysics-and the Gamma-Ray Imager Mission GRI

    DEFF Research Database (Denmark)

    Wunderer, C. B.; Ballmoos, P. V.; Barriere, N.;

    2009-01-01

    , albeit at much more modest sensitivities. There will be clearly a growing need to perform deeper, more focused investigations of gamma-ray sources in the 100-keV to MeV regime. Recent technological advances in the domain of gamma-ray focusing using Lane diffraction and multilayer-coated mirror techniques......Observations of the gamma-ray sky reveal the most powerful sources and the most violent events in the Universe. While at lower wavebands the observed emission is generally dominated by thermal processes, the gamma-ray sky provides us with a view on the non-thermal Universe. Here particles are...... accelerated to extreme relativistic energies by mechanisms which are still poorly understood, and nuclear reactions are synthesizing the basic constituents of our world. Cosmic accelerators and cosmic explosions are major science themes that are addressed in the gamma-ray regime. While Fermi will take the...

  9. Measurement of K{sup {+-}}{yields}{pi}{sup {+-}}{gamma}{gamma} decays

    Energy Technology Data Exchange (ETDEWEB)

    Morales Morales, Cristina

    2009-07-21

    The goal of this thesis was an experimental test of an effective theory of strong interactions at low energy, called Chiral Perturbation Theory (ChPT). Weak decays of kaon mesons provide such a test. In particular, K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} decays are interesting because there is no tree-level O(p{sup 2}) contribution in ChPT, and the leading contributions start at O(p{sup 4}). At this order, these decays include one undetermined coupling constant, c. Both the branching ratio and the spectrum shape of K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} decays are sensitive to this parameter. O(p{sup 6}) contributions to K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} ChPT predict a 30-40% increase in the branching ratio. From the measurement of the branching ratio and spectrum shape of K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} decays, it is possible to determine a model dependent value of c and also to examine whether the O(p{sup 6}) corrections are necessary and enough to explain the rate. About 40% of the data collected in the year 2003 by the NA48/2 experiment have been analyzed and 908 K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} candidates with about 8% background contamination have been selected in the region with z=m{sup 2}{sub {gamma}}{sub {gamma}}/m{sub K}{sup 2}{>=}0.2. Using 5,750,121 selected K{sup {+-}} {yields} {pi}{sup {+-}}{pi}{sup 0} decays as normalization channel, a model independent differential branching ratio of K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} has been measured to be: BR(K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma}, z{>=}0.2)=(1.018{+-}0.038{sub stat}{+-}0.039{sub syst}{+-}0.004{sub ext}).10{sup -6}. From the fit to the O(p{sup 6}) ChPT prediction of the measured branching ratio and the shape of the z-spectrum, a value of c=1.54{+-}0.15{sub stat}{+-}0.18{sub syst} has been extracted. Using the measured c value and the O(p{sup 6}) ChPT prediction, the branching ratio for z=m{sup 2}{sub

  10. Gamma response study of radiation sensitive MOSFETs for their use as gamma radiation sensor

    Science.gov (United States)

    Srivastava, Saurabh; Aggarwal, Bharti; Singh, Arvind; Kumar, A. Vinod; Topkar, Anita

    2016-05-01

    Continuous monitoring of gamma dose is important in various fields like radiation therapy, space-related research, nuclear energy programs and high energy physics experiment facilities. The present work is focused on utilization of radiation-sensitive Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) to monitor gamma radiation doses. Static characterization of these detectors was performed to check their expected current-voltage relationship. Threshold voltage and transconductance per unit gate to source voltage (K factor) were calculated from the experimental data. The detector was exposed to gamma radiation in both, with and without gate bias voltage conditions, and change in threshold voltage was monitored at different gamma doses. The experimental data was fitted to obtain equation for dependence of threshold voltage on gamma dose. More than ten times increase in sensitivity was observed in biased condition (+3 V) compared to the unbiased case.

  11. Four-fermion production at gamma gamma colliders: 2. Radiative corrections in double-pole approximation

    CERN Document Server

    Bredenstein, A; Roth, M

    2005-01-01

    The O(alpha) electroweak radiative corrections to gamma gamma --> WW --> 4f within the electroweak Standard Model are calculated in double-pole approximation (DPA). Virtual corrections are treated in DPA, leading to a classification into factorizable and non-factorizable contributions, and real-photonic corrections are based on complete lowest-order matrix elements for gamma gamma --> 4f + gamma. Soft and collinear singularities appearing in the virtual and real corrections are combined alternatively in two different ways, namely by using the dipole subtraction method or by applying phase-space slicing. The radiative corrections are implemented in a Monte Carlo generator called COFFERgammagamma, which optionally includes anomalous triple and quartic gauge-boson couplings in addition and performs a convolution over realistic spectra of the photon beams. A detailed survey of numerical results comprises O(alpha) corrections to integrated cross sections as well as to angular, energy, and invariant-mass distributi...

  12. GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

    International Nuclear Information System (INIS)

    The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

  13. GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Straalberg, E. (ed.) (Institute for Energy Technolgy (Norway)); Berg, K. (National Institute of Radiation Protection (Denmark)); Dowdall, M. (Norwegian Radiation Protection Authority (Norway)) (and others)

    2010-11-15

    The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

  14. Influence of the temperature in the measurement of the gamma automatic probe Gamma Tracer; Influencia de la temperatura en la medicion de la sonda gamma automatica Gamma Tracer

    Energy Technology Data Exchange (ETDEWEB)

    Caveda R, C.A.; Dominguez L, O.; Alonso A, D. [CPHR, Calle 20 No. 4113 e/41 y 47, Playa, C.P. 11300, A.P. 6195, C.P. 10600 La Habana (Cuba); Montalvan E, A.; Fabelo B, O. [CIAC, Ave. Finlay Km 2 1/2, Rpto. Puerto Principe, Camaguey 70800 (Cuba)]. e-mail: caveda@cphr.edu.cu

    2006-07-01

    In the following work an analysis of the existent relationship among the measurement of the absorbed dose rate in air due to the environmental gamma radiation and the temperature, magnitudes measured to intervals of 10 minutes by the gamma probe Gamma Tracer located in the post of occident of the National Net of Environmental Radiological Surveillance (RNVRA), in the Center of Protection and Hygiene of the Radiations (CPHR) is made. For it its were analyzed near 100,000 measurements corresponding to the period 2004-2005. For a better processing and interpretation of the data, these were analyzed with one frequency time zone and monthly using the Gamma Red software to which was necessary to add it some options. Finally it was submitted the probe to a heating process inside a stove. The results of the carried out experiments confirmed that the absorbed dose rate in air due to the environmental gamma radiation depends potentially of the probe temperature in the range of environmental temperature to which is subjected daily the same one. (Author)

  15. Stellar Photon Archaeology with Gamma-Rays

    Science.gov (United States)

    Stecker, Floyd W.

    2009-01-01

    Ongoing deep surveys of galaxy luminosity distribution functions, spectral energy distributions and backwards evolution models of star formation rates can be used to calculate the past history of intergalactic photon densities and, from them, the present and past optical depth of the Universe to gamma-rays from pair production interactions with these photons. The energy-redshift dependence of the optical depth of the Universe to gamma-rays has become known as the Fazio-Stecker relation (Fazio & Stecker 1970). Stecker, Malkan & Scully have calculated the densities of intergalactic background light (IBL) photons of energies from 0.03 eV to the Lyman limit at 13.6 eV and for 0$ < z < $6, using deep survey galaxy observations from Spitzer, Hubble and GALEX and have consequently predicted spectral absorption features for extragalactic gamma-ray sources. This procedure can also be reversed. Determining the cutoff energies of gamma-ray sources with known redshifts using the recently launched Fermi gamma-ray space telescope may enable a more precise determination of the IBL photon densities in the past, i.e., the "archaeo-IBL.", and therefore allow a better measure of the past history of the total star formation rate, including that from galaxies too faint to be observed.

  16. GRI: the gamma-ray imager mission

    CERN Document Server

    Knödlseder, J

    2006-01-01

    Observations of the gamma-ray sky reveal the most powerful sources and the most violent events in the Universe. While at lower wavebands the observed emission is generally dominated by thermal processes, the gamma-ray sky provides us with a view on the non-thermal Universe. Here particles are accelerated to extreme relativistic energies by mechanisms which are still poorly understood, and nuclear reactions are synthesizing the basic constituents of our world. Cosmic accelerators and cosmic explosions are the major science themes that are addressed in the gamma-ray regime. With the INTEGRAL observatory, ESA has provided a unique tool to the astronomical community revealing hundreds of sources, new classes of objects, extraordinary views of antimatter annihilation in our Galaxy, and fingerprints of recent nucleosynthesis processes. While INTEGRAL provides the global overview over the soft gamma-ray sky, there is a growing need to perform deeper, more focused investigations of gamma-ray sources. In soft X-rays a...

  17. Gamma-ray binaries and related systems

    CERN Document Server

    Dubus, Guillaume

    2013-01-01

    After initial claims and a long hiatus, it is now established that several binary stars emit high (0.1-100 GeV) and very high energy (>100 GeV) gamma rays. A new class has emerged called 'gamma-ray binaries', since most of their radiated power is emitted beyond 1 MeV. Accreting X-ray binaries, novae and a colliding wind binary (eta Car) have also been detected - 'related systems' that confirm the ubiquity of particle acceleration in astrophysical sources. Do these systems have anything in common ? What drives their high-energy emission ? How do the processes involved compare to those in other sources of gamma rays: pulsars, active galactic nuclei, supernova remnants ? I review the wealth of observational and theoretical work that have followed these detections, with an emphasis on gamma-ray binaries. I present the current evidence that gamma-ray binaries are driven by rotation-powered pulsars. Binaries are laboratories giving access to different vantage points or physical conditions on a regular timescale as ...

  18. Status of the Milagro Gamma Ray Observatory

    CERN Document Server

    Maryland Univ. College Park

    2001-01-01

    The Milagro Gamma Ray Observatory, located at an altitude of 8,600 feet in the Jemez Mountains of New Mexico, is the world's first large-area water Cherenkov detector capable of continuously monitoring the entire sky for sources of TeV gamma rays. It is uniquely capable of searching for transient sources of VHE gamma rays. The core of the detector is a 60m x 80m x 8m pond instrumented with 723 PMTs deployed in two layers. This part of the detector is complete and has operated continuously since Jan. 2000. Initial studies including searches for gamma-ray sources are ongoing, and preliminary results are available. The final stage of construction is under way. We are deploying 170 auxiliary "outrigger" water Cherenkov detectors in an area of 40,000 square-meters surrounding the pond, which will significantly enhance our ability to reject background and more accurately reconstruct the gamma-ray direction and energy. In addition, we are lowering the energy threshold of the detector by using custom processing to en...

  19. GAMPIX: A new generation of gamma camera

    Science.gov (United States)

    Gmar, M.; Agelou, M.; Carrel, F.; Schoepff, V.

    2011-10-01

    Gamma imaging is a technique of great interest in several fields such as homeland security or decommissioning/dismantling of nuclear facilities in order to localize hot spots of radioactivity. In the nineties, previous works led by CEA LIST resulted in the development of a first generation of gamma camera called CARTOGAM, now commercialized by AREVA CANBERRA. Even if its performances can be adapted to many applications, its weight of 15 kg can be an issue. For several years, CEA LIST has been developing a new generation of gamma camera, called GAMPIX. This system is mainly based on the Medipix2 chip, hybridized to a 1 mm thick CdTe substrate. A coded mask replaces the pinhole collimator in order to increase the sensitivity of the gamma camera. Hence, we obtained a very compact device (global weight less than 1 kg without any shielding), which is easy to handle and to use. In this article, we present the main characteristics of GAMPIX and we expose the first experimental results illustrating the performances of this new generation of gamma camera.

  20. Transuranic isotopic analysis using gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D; Decman, D

    1998-10-15

    Transuranic waste typically emits gamma rays that are characteristic of the isotopic composition of the materials. If the area of the gamma ray photopeaks in a High Purity Ge (HPGe) spectrum can be accurately determined and if the gamma ray/x-ray branching ratios and half-lives for the radionuclides in the sample are known the relative concentration of each isotope in the waste can be determined using tomographic techniques. Methods used to accurately determine these photopeaks usually requires a computer code that does multi-peak analysis and unfolding of a given part of the gamma-ray spectrum. Computer techniques allow an accurate determination of the photopeaks and hence the isotopic composition of the waste material. These computer techniques can be automated for different spectra within a wide range of possible isotopic compositions. To improve photopeak statistics all of the spectra taken in a tomographic survey of the sample are summed and are used in the isotopic analysis. The method, accuracy, and limitations of this type of isotopic analysis system will be discussed. The gamma ray acquisition system is currently being upgraded with multiple HPGe detectors to improve the counting statistics obtainable in a given amount of time. The results of the DOE performance evaluations and the progress of the multiple detector upgrade will be discussed.

  1. Stratospheric discharges during solar gamma flares

    International Nuclear Information System (INIS)

    It is known that specifics of angle distribution of recoiling electrons being generated at the Compton scattering process of the gamma quanta (electrons flight angles spectrum is [0,180 deg.]) creates favourable conditions for the production of after-collision electron flux along the original direction of the gamma quanta motion, which means that electric current is initiated. The weak values of the gamma ray fluxes from sources in space made difficult the geophysical applications of this concept. However, recent investigations have shown that taking into consideration the real variations of the energy spectrum of space gamma rays may increase significantly the impact of the weak stratosphere currents on the parameters of the global atmosphere-ionosphere electric circuit. Earlier, this theoretical model has been used as a possible basis of the direct driven mechanism of development of the large-scale geomagnetic oscillations during solar gamma flares. This paper emphasizes the storage-release aspect of the stratosphere currents occurring in the light of the corresponding electric field generation and discusses the probability of electric breakdown at the sub-ionosphere altitudes. (rapid communication)

  2. Gamma Radiation Effects on Peanut Skin Antioxidants

    Directory of Open Access Journals (Sweden)

    Adriano Costa de Camargo

    2012-03-01

    Full Text Available Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached-deodorized (RBD soybean oil. The oxidative stability of the oil samples was determined using the Oil Stability Index method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ. Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. All extracts, gamma irradiated or not, presented increasing induction period (h, measured by the Oil Stability Index method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT. The present study confirmed that gamma radiation did not affect the peanut skin extracts’ antioxidative properties when added to soybean oil.

  3. Gamma-Ray Astronomy from the Ground

    CERN Document Server

    Horns, D

    2016-01-01

    The observation of cosmic gamma-rays from the ground is based upon the detection of gamma-ray initiated air showers. At energies between approximately $10^{11}$ eV and $10^{13}$ eV, the imaging air Cherenkov technique is a particularly successful approach to observe gamma-ray sources with energy fluxes as low as $\\approx 10^{-13}$ erg\\,cm$^{-2}\\,$s$^{-1}$. The observations of gamma-rays in this energy band probe particle acceleration in astrophysical plasma conditions and are sensitive to high energy phenomena beyond the standard model of particle physics (e.g., self-annihilating or decaying dark matter, violation of Lorentz invariance, mixing of photons with light pseudo-scalars). The current standing of the field and its major instruments are summarised briefly by presenting selected highlights. A new generation of ground based gamma-ray instruments is currently under development. The perspectives and opportunities of these future facilities will be discussed.

  4. Gamma radiographic exposure time indicator

    International Nuclear Information System (INIS)

    In industrial radiography, with the proper selection of source and film, the radiographic quality depends very much on the exposure time, which in turn depends upon the source strength and the source to film distance. Conventional methods to arrive at correct exposure time involve time consuming calculations and in these methods the knowledge of the above mentioned parameters is imperative. An instrument to determine the required exposure time has been developed which indicates exposure times in about 30 secs. This covers two commonly used gamma radiography sources, viz., 192Ir and 60Co and six commonly used radiography films of different speeds. Knowledge of source strength and source to film distance is not required with the use of this instrument. With a knowledge of the total exposure required by the film to give the required sensitivity and by the measurement of radiation level at the film location, the correct exposure time is determined. The radiation level is measured by placing a GM counter behind the radiographic specimen at the film location. To match the responses of the film and the GM counter, the counter is incorporated in a suitably designed probe. In this instruments, an integrator to integrate the GM-pulses and a constant current integrator (timer) are started simultaneously. The voltage at the GM-pulse integrator is compared with a preselected voltage, (selected on the basis of film type, source, source strength and order of object thickness) by a comparator. The comparator is so adjusted that when the GM-pulse integrator voltage exceeds the preselected voltage, it switches its state and stops the integration of constant current. The constant current integrator output which is proportional to the time taken for the GM-pulse integrator to reach the preselected voltage, is read on a meter graduated in terms of exposure time. The instrument can measure exposure times from 5 minutes to 10 hours read in two ranges, the range-changing being automatic

  5. Urban gamma spectrometry. Report 1

    International Nuclear Information System (INIS)

    This report contains the present status and results for the NKS UGS-project per 1 June 2006 for NKS partners DTU, Denmark, and STUK, Finland. The Danish and Finnish CGS (Carborne Gamma Spectrometry) systems are not of similar types. The Danish CGS system(s) only make use of one NaI(Tl) detector whereas the Finnish CGS system consists of several detectors, NaI(Tl) and HPGe both and as an additional feature the Finnish detectors have position dependent different fields of view. Furthermore, the Finnish system is equipped with an air sampling system. In terms of operation, the Danish detector is located on the rooftop where as the Finnish detectors are located inside the vehicle. The Finnish and the Danish team use different methods for data processing. STUK uses a hypothesis test method to get robust real time alarms (within 10 seconds) when significant peaks from a previously defined set of nuclides are detected. An alarm for a significantly elevated total pulse rate is sent if none of the predefined nuclides is identified. All data are stored to the LINSSI database, which facilitates easy data retrieval for post processing. DEMA/DTU bases their calculations on full spectrum fitting using NASVD and the Danish software NucSpec. Source signals are found from spectrum fitting residuals or from stripping of energy windows - either by the standard 4-windows method or by a measurement based method where stripping factors for any window of interest can be derived from the measurements themselves. A thorough description of the two systems and data processing methods (including mathematics) are described in this report. For the Danish methods of data processing some comparisons have been made, but no final conclusion has been reached yet. Raw urban data has been investigated along with urban data sets to which source signals have been added and searched for. For the Finnish method calibration plots of the minimum detection limits for two different detector types have been

  6. Urban gamma spectrometry. Report 1

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H. (Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2009-06-15

    This report contains the present status and results for the NKS UGS-project per 1 June 2006 for NKS partners DTU, Denmark, and STUK, Finland. The Danish and Finnish CGS (Carborne Gamma Spectrometry) systems are not of similar types. The Danish CGS system(s) only make use of one NaI(Tl) detector whereas the Finnish CGS system consists of several detectors, NaI(Tl) and HPGe both and as an additional feature the Finnish detectors have position dependent different fields of view. Furthermore, the Finnish system is equipped with an air sampling system. In terms of operation, the Danish detector is located on the rooftop where as the Finnish detectors are located inside the vehicle. The Finnish and the Danish team use different methods for data processing. STUK uses a hypothesis test method to get robust real time alarms (within 10 seconds) when significant peaks from a previously defined set of nuclides are detected. An alarm for a significantly elevated total pulse rate is sent if none of the predefined nuclides is identified. All data are stored to the LINSSI database, which facilitates easy data retrieval for post processing. DEMA/DTU bases their calculations on full spectrum fitting using NASVD and the Danish software NucSpec. Source signals are found from spectrum fitting residuals or from stripping of energy windows - either by the standard 4-windows method or by a measurement based method where stripping factors for any window of interest can be derived from the measurements themselves. A thorough description of the two systems and data processing methods (including mathematics) are described in this report. For the Danish methods of data processing some comparisons have been made, but no final conclusion has been reached yet. Raw urban data has been investigated along with urban data sets to which source signals have been added and searched for. For the Finnish method calibration plots of the minimum detection limits for two different detector types have been

  7. INTEGRAL & RXTE View of Gamma-ray Binaries

    OpenAIRE

    Jian LI; Torres, Diego F.; Zhang, Shu; WANG, JIANMIN

    2013-01-01

    Gamma-ray binaries are X-ray binaries with gamma-ray emissions. Their multi-wavelength emissions range from radio, optical, X-ray and to very high energy (TeV). X-ray emissions are crucial to understand the nature of gamma-ray binaries. INTEGRAL and RXTE have covered and monitored most of the gamma-ray binaries in hard and soft X-rays. Here we report the results of several gamma-ray binaries and possible gamma-ray binaries from INTEGRAL and RXTE.

  8. Heliospheric Origin of $\\gamma$-Ray Bursts

    CERN Document Server

    Li Ti Pei

    1997-01-01

    Systematic variations of average observational characteristics and correlation properties between different parameters of gamma-ray bursts (GRBs) with time from 1991 April to 1994 September are revealed. It is hard to explain the observed long-term variability by variations of experimental conditions. The variability of GRB properties with the time scale of months to years, together with the similarity between GRBs, solar hard X-ray flares and terrestrial gamma-ray flashes, may indicate an origin of GRBs, at least partly, within the heliosphere. Large-voltage and high-temperature pinch plasma columns produced by disruptive electrical discharges in the outer heliosphere can generate hard X-ray and gamma-ray flashes with energy spectra and spectral evolution characters consistent with that observed in GRBs.

  9. Effects of gamma radiation in tomato seeds

    Energy Technology Data Exchange (ETDEWEB)

    Wiendl, Toni A.; Wiendl, Fritz W.; Franco, Suely S.H.; Franco, Jose G.; Althur, Valter, E-mail: tawiendl@hotmail.com, E-mail: gilmita@uol.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2013-07-01

    Tomato dry seeds of the hybrid 'Gladiador' F1 were exposed to low doses of gamma radiation from Co-60 source at 0,509 kGy tax rate in order to study stimulation effects of radiation on germination and plant growth. Eight treatments radiation doses were applied as follows: 0 (control); 2,5; 5,0; 7,5; 10,0; 12,5; 15,0; 20,0 Gy. Seed germination as well as green fruits number, harvested fruit number, fruit weight and total production were assessed to identify occurrence of stimulation. Tomato seeds and plants were handled as for usual tomato production in Brazil. Low doses of gamma radiation treatment in the seeds stimulate germination and substantially increase fruit number and total production up to 86% at 10 Gy dose. There are evidences that the use of low doses of gamma radiation can stimulate germination and plant production thus, showing hormetic effects. (author)

  10. Very high count rate gamma spectroscopy

    International Nuclear Information System (INIS)

    Recent improvements in the electronics that amplify and analyze gamma photon-induced pulses have made it possible for HPGe coaxial detectors to accept input rates of one-million, one-MeV gamma photons-per-second and still provide the spectroscopist with spectra that can be analyzed. Data are presented that illustrate peak area variances and changes in counting uncertainty statistics due to the greatly extended count rate range. Software algorithms are presented that allow gain shift and peak resolution to be adjusted automatically on a sample-by-sample basis. Relationships are developed between integrated count rate and the variances of full energy photon peak area and counting uncertainty when using the real time correction mode of pulse processing. Finally, the results of integrating hardware and software into a system are used to illustrate that quantitative gamma spectroscopy over counting rates of one- to one-million counts-per-second are achievable

  11. Nondestructive gamma activation analysis of mineral materials

    International Nuclear Information System (INIS)

    The basic problems are described related to the use of gamma activation analysis. The applicability was studied of instrumental gamma activation analysis (IGAA) in geology. A number of minerals, rocks, marine sediments and reference materials were studied. For irradiation a betatron and a microtron were used. The results show that IGAA allows the simultaneous determination of a number of trace elements at concentrations of tenths of ppm. The results are given of comparisons made of the analytical possibilities of microtron IGAA and reactor INAA in geology. Tables show the results of the application of IGAA, the main products and parameters of photoexcitation reactions and graphically represented are the gamma spectra of measured materials. (J.B.)

  12. Dose rate levels around industrial gamma sources

    International Nuclear Information System (INIS)

    Dose rate levels around two gamma ray sources utilized in a mining corporation have been determined. Both gamma ray sources are 137Cs and are installed in a mining corporation to measure on-line the density of mine products. Dose rate levels were calculated in several sites around the 137Cs sources using two active and several passive thermoluminescent dosemeters. Using the 137Cs' gamma factor dose rates were calculated in all the points. A comparison between the measured and calculated dose rate levels was carried out. Calculated dose rate levels was obtained for three cases: first, assuming the sources were bare, second, assuming the sources inside their shielding and the third, adding an extra shield to reduce the dose rate levels to those similar to local background. (author)

  13. Gamma Ray Astronomy with Magnetized Zevatrons

    CERN Document Server

    Armengaud, E; Miniati, F; Armengaud, Eric; Sigl, Guenter; Miniati, Francesco

    2005-01-01

    Nearby sources of cosmic rays up to a ZeV(=10^21 eV) could be observed with a multi-messenger approach including secondary gamma-rays and neutrinos. If cosmic rays above ~10^18 eV are produced in magnetized environments such as galaxy clusters, the flux of secondary gamma-rays below ~1 TeV can be enhanced up to several orders of magnitudes compared to unmagnetized sources. A particular source of enhancement are synchrotron and cascade photons from e^+e^- pairs produced by protons from sources with relatively steep injection spectra proportional to E^-2.6. Such sources should be visible at the same time in ultra-high energy cosmic ray experiments and gamma-ray telescopes.

  14. Gamma ray source studies using muon tracking

    International Nuclear Information System (INIS)

    A large area (128 m2) streamer tube detector, located within the KASCADE-Grande experiment has been built. We discuss the possibility of observing gamma-ray sources by means of photo-pion produced single isolated muon tracks above the background of cosmic-ray muons using a muon tracking detector (MTD). Properties of the photo-production process in the atmosphere and of the MTD which support the identification of gammas are discussed. The sensitivity of the technique of observing the Crab energy spectrum in the tens of GeV range is discussed. Gamma spectra accumulated from Crab and a Mrk 421 flux correlation with X-ray (RXTE/PCA) are presented.

  15. Gamma sensitivity of thin gap chamber

    International Nuclear Information System (INIS)

    The Large Hadron Collider (LHC) at the European Laboratory for Particle Physics (CERN) is expected to operate at lower luminosity (1033 cm-2s-1) for the first three years and at the full luminosity of 1034 cm-2s-1 by year 2008 and on. Thin Gap Chamber (TGC) must operate under this high luminosity. Therefore there will be enormous background whose effect have to be estimated. The main particles in the background radiation are neutrons and photons. In this report, the sensitivity of TGC for gammas with energy from 20 keV to 1.8 MeV have been measured using radioactive sources. The measured sensitivity was compared with results from calculations of the Monte Carlo simulation code called EGS4 (Electron Gamma Shower). The average sensitivity of the TGC for gammas is about 1%. (author)

  16. Technology Needs for Gamma Ray Astronomy

    Science.gov (United States)

    Gehrels, Neil

    2011-01-01

    Gamma ray astronomy is currently in an exciting period of multiple missions and a wealth of data. Results from INTEGRAL, Fermi, AGILE, Suzaku and Swift are making large contributions to our knowledge of high energy processes in the universe. The advances are due to new detector and imaging technologies. The steps to date have been from scintillators to solid state detectors for sensors and from light buckets to coded aperture masks and pair telescopes for imagers. A key direction for the future is toward focusing telescopes pushing into the hard X-ray regime and Compton telescopes and pair telescopes with fine spatial resolution for medium and high energy gamma rays. These technologies will provide finer imaging of gamma-ray sources. Importantly, they will also enable large steps forward in sensitivity by reducing background.

  17. New insights from cosmic gamma rays

    CERN Document Server

    Diehl, Roland

    2016-01-01

    The measurement of gamma rays from cosmic sources at MeV energies is one of the key tools for nuclear astrophysics, in its study of nuclear reactions and their impacts on objects and phenomena throughout the universe. Gamma rays trace nuclear processes most directly, as they originate from nuclear transitions following radioactive decays or high-energy collisions with excitation of nuclei. Additionally, the unique gamma-ray signature from the annihilation of positrons falls into this astronomical window and is discussed here: Cosmic positrons are often produced from beta-decays, thus also of nuclear physics origins. The nuclear reactions leading to radioactive isotopes occur inside stars and stellar explosions, which therefore constitute the main objects of such studies. In recent years, both thermonuclear and core-collapse supernova radioactivities have been measured, and complement conventional supernova observations with measurements of their prime energy sources. The diffuse radioactive afterglow of massi...

  18. Form factors of the transitions {gamma}{sup *}{pi}{sup 0} {r_arrow} {gamma} and {gamma}{sup *}{eta}{r_arrow}{gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Afanasev, A. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States)

    1994-04-01

    The author discusses possibilities to study {gamma}*{pi}{sup 0} and {gamma}*{eta} {r_arrow} {gamma} transition form factors at CEBAF energies. The author shows that for 4 GeV electron beam, these form factors can be measured at CEBAF for the 4-momentum transfers Q{sup 2} {le} 2.5 (GeV/c){sup 2} using virtual Compton scattering on the proton and nuclear target in the kinematic regime of low momentum transfers to the target. These measurements can be extended to Q{sup 2} {le} 4.0 (GeV/c){sup 2} using the electron beam with the energy 6 GeV.

  19. Computed transaxial imaging using single gamma emitters

    International Nuclear Information System (INIS)

    Emission computed tomography (ECT) studies were performed on test objects and dogs. Conjugate views were obtained for 60 to 120 projections equispaced around 3600 by rotation of the subjects in front of a gamma camera. A convolution reconstruction algorithm in which gamma ray attenuation corrections are included in the backprojection step were used to reconstruct the emission images. Reconstructions of x-ray transmission data provided data for gamma ray attenuation corrections of the emission images of /sup 99m/Tc-pyrophosphate uptake in dogs. Reconstructed images of test objects show spatial resolution uniformity, and attenuation corrections enable estimation of relative activity densities to within 10 to 15% rms errors, thus demonstrating quantitative imaging capabilities of emission CT

  20. Gamma-ray bursters at cosmological distances

    Science.gov (United States)

    Paczynski, B.

    1986-01-01

    It is proposed that some, perhaps most, gamma-ray bursters are at cosmological distances, like quasars, with a redshift of about 1 or 2. This proposition requires a release of supernova-like energy of about 10 to the 51st ergs within less than 1 s, making gamma-ray bursters the brightest objects known in the universe, many orders of magnitude brighter than any quasars. This power must drive a highly relativistic outflow of electron-positron plasma and radiation from the source. It is proposed that three gamma-ray bursts, all with identical spectra, detected from B1900 + 14 by Mazets, Golenetskii, and Gur'yan and reported in 1979, were all due to a single event multiply imaged by a gravitational lens. The time intervals between the successive bursts, 10 hr to 3 days, were due to differences in the light travel time for different images.

  1. Gamma spectrometrical examination of irradiated fuel

    International Nuclear Information System (INIS)

    Gamma scanning is the only non-destructive technique for quantitative measuring of fission or activation products in spent fuel. The negligence of local variation of the linear attenuation coefficient of gamma rays in the irradiated fuel remains the main source of systematic error. To eliminate it we combine the (single) emission gamma ray scanning technique with a transmission measurement. Mathematical procedure joined with the experiment is particularly convenient for fuel elements of circular cross-section. In such a manner good results are obtainable even for relatively small number of measuring data. Accomplished routines enable to esteem the finite width of the collimation slit. The experiment has been partially automated. Trial measurements were carried out, and the measured data were successfully processed

  2. Low radioactivity spectral gamma calibration facility

    International Nuclear Information System (INIS)

    A low radioactivity calibration facility has been constructed at the Nevada Test Site (NTS). This facility has four calibration models of natural stone that are 3 ft in diameter and 6 ft long, with a 12 in. cored borehole in the center of each model and a lead-shielded run pipe below each model. These models have been analyzed by laboratory natural gamma ray spectroscopy (NGRS) and neutron activation analysis (NAA) for their K, U, and Th content. Also, 42 other elements were analyzed in the NAA. The 222Rn emanation data were collected. Calibrating the spectral gamma tool in this low radioactivity calibration facility allows the spectral gamma log to accurately aid in the recognition and mapping of subsurface stratigraphic units and alteration features associated with unusual concentrations of these radioactive elements, such as clay-rich zones

  3. Probing the H$^{3}$ vertex in e+e-, $\\gamma$e and $\\gamma\\gamma$ collisions for light and intermediate Higgs bosons

    CERN Document Server

    Ilyin, V A; Kurihara, Y; Pukhov, A E; Shimizu, Y

    1996-01-01

    We have studied double Higgs production at future linear colliders while paying special attention to the option of high-energy and high-luminosity photon beams. The main purpose was to examine the feasibility of e+e-, e-gamma and gamma-gamma colliders in order to probe the anomalous triple Higgs coupling, which is crucial for understanding the Standard Model. We considered mainly the cases of light and intermediate Higgs bosons. Double Higgs production is almost background free, except in the MH=MZ mass range, which is discussed separately. It is shown that for a light Higgs boson the HHH coupling can be measured even at e+e- collider at 500 GeV. For a intermediate Higgs boson a collider in the TeV region is suitable for such an investigation. We have estimated the bounds on the anomalous HHH coupling, which can be experimentally established using future linear colliders.

  4. Plasma driven neutron/gamma generator

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Ka-Ngo; Antolak, Arlyn

    2015-03-03

    An apparatus for the generation of neutron/gamma rays is described including a chamber which defines an ion source, said apparatus including an RF antenna positioned outside of or within the chamber. Positioned within the chamber is a target material. One or more sets of confining magnets are also provided to create a cross B magnetic field directly above the target. To generate neutrons/gamma rays, the appropriate source gas is first introduced into the chamber, the RF antenna energized and a plasma formed. A series of high voltage pulses are then applied to the target. A plasma sheath, which serves as an accelerating gap, is formed upon application of the high voltage pulse to the target. Depending upon the selected combination of source gas and target material, either neutrons or gamma rays are generated, which may be used for cargo inspection, and the like.

  5. Delayed gamma technique for fissile material assay

    Energy Technology Data Exchange (ETDEWEB)

    Mozin, Vladimir [Los Alamos National Laboratory; Tobin, Stephen [Los Alamos National Laboratory; Vujie, Jasmina [UC BERKELEY; Hunt, Alan [IDAHO ACCELERATOR CENTER

    2010-01-01

    Research sponsored by the Next Generation Safeguards Initiative are investigating several non-destructive assay techniques for the quantification of fissile plutonium mass in spent nuclear fuel assemblies. AppHcation of the delayed gamma signatures is investigated in this context. The objective of the research is to assess whether the delayed gamma assay instrument can provide sufficient sensitivity, isotope specificity and accuracy as required in nuclear material safeguards. This effort includes theoretical and experimental components for the optimal combination of interrogation parameters. A new modeling algorithm offering a high level of detail was developed specifically for this purpose and was validated in series of benchmark experiments. Preliminary modeling of the delayed gamma response from spent fuel assemblies was accomplished offering a future direction for the design process.

  6. Computer based integral gamma activity measurement system

    International Nuclear Information System (INIS)

    PC based Integral Gamma Activity measurement system has been developed for measuring the gross gamma activity. The Integral system comprises of the Ion chamber, electrometer amplifier and data acquisition system. This system is used for measuring the activity and also for recording of the decay characteristics. A windows based computer program has been developed for data acquisition and storage during the experiment. The system records the detector current output in the range of 10 pA to 10 nA. The measured current was converted into pre-calibrated gross gamma activity which was used for estimating the power distribution within the reactor core. The paper describes development of the system including the experiment results. (author)

  7. Effects of gamma radiation in tomato seeds

    International Nuclear Information System (INIS)

    Tomato dry seeds of the hybrid 'Gladiador' F1 were exposed to low doses of gamma radiation from Co-60 source at 0,509 kGy tax rate in order to study stimulation effects of radiation on germination and plant growth. Eight treatments radiation doses were applied as follows: 0 (control); 2,5; 5,0; 7,5; 10,0; 12,5; 15,0; 20,0 Gy. Seed germination as well as green fruits number, harvested fruit number, fruit weight and total production were assessed to identify occurrence of stimulation. Tomato seeds and plants were handled as for usual tomato production in Brazil. Low doses of gamma radiation treatment in the seeds stimulate germination and substantially increase fruit number and total production up to 86% at 10 Gy dose. There are evidences that the use of low doses of gamma radiation can stimulate germination and plant production thus, showing hormetic effects. (author)

  8. Evaluation of gamma-ray intensities

    International Nuclear Information System (INIS)

    Relative intensities and intensities per decay of gamma rays were evaluated for 16 nuclides, 22Na, 24Na, 46Sc, 54Mn, 60Co, 85Sr, 88Y, 95Nb, sup(108m)Ag, 134Cs, 133Ba, 139Ce, sup(180m)Hf, 198Au, 203Hg and 207Bi. For most of these nuclides disintegration rates can be determined by means of β-γ or X-γ coincidence method. Since decay schemes of these nuclides are established, intensities per decay of strong gamma rays were accurately evaluated by using weak beta-ray branching ratios, relative gamma-ray intensities and internal conversion coefficients. Half-lives of the nuclides were also evaluated. Use of the nuclides, therefore, are recommended for precision intensity calibration of the detectors. (author)

  9. Progress in gamma-camera quality control

    International Nuclear Information System (INIS)

    The latest developments in the art of quality control of gamma cameras are emphasized in a simple historical manner. The exhibit describes methods developed by the Bureau of Radiological Health (BRH) in comparison with previously accepted techniques for routine evaluation of gamma-camera performance. Gamma cameras require periodic testing of their performance parameters to ensure that their optimum imaging capability is maintained. Quality control parameters reviewed are field uniformity, spatial distortion, intrinsic and spatial resolution, and temporal resolution. The methods developed for the measurement of these parameters are simple, not requiring additional electronic equipment or computers. The data has been arranged in six panels as follows: schematic diagrams of the most important test patterns used in nuclear medicine; field uniformity; regional displacements in transmission pattern image; spatial resolution using the BRH line-source phantom; instrinsic resolution using the BRH Test Pattern; and Temporal resolution and count losses at high counting rates

  10. Solution To The Gamma Ray Burst Mystery?

    CERN Document Server

    Dar, Arnon

    1996-01-01

    Photoexcitation and ionization of partially ionized heavy atoms in highly relativistic flows by interstellar photons, followed by their reemission in radiative recombination and decay, boost star-light into beamed $\\gamma$ rays along the flow direction. Repeated excitation/decay of highly relativistic baryonic ejecta from merger or accretion induced collapse of neutron stars in dense stellar regions (DSRs), like galactic cores, globular clusters and super star-clusters, can convert enough kinetic energy in such events in distant galaxies into cosmological gamma ray bursts (GRBs). The model predicts remarkably well all the main observed temporal and spectral properties of GRBs. Its success strongly suggests that GRBs are $\\gamma$ ray tomography pictures of DSRs in galaxies at cosmological distances with unprecedented resolution: A time resolution of $dt\\sim 1~ms$ in a GRB can resolve stars at a Hubble distance which are separated by only $D\\sim 10^{10}cm$. This is equivalent to the resolving power of an optica...

  11. Gamma Radiosensitivity Study on Chili (Capsicum annuum

    Directory of Open Access Journals (Sweden)

    Shairul R.  Omar

    2008-01-01

    Full Text Available Induced mutation by gamma irradiation has been found to be a very useful technique for crop improvement. Apart from this, the proper use of induced mutation in plant breeding has become a profitable approach. This investigation was carried out to determine the LD50 and effect of gamma rays on germination, plant height, survival percentage, root length, root dry weight and shoot dry weight of seedlings derived from irradiated seeds of chili (Capsicum annuum. Seeds of chili were treated with 300, 400, 500, 600 and 800 Gy gamma rays at Malaysian Institute of Nuclear Technology (MINT. The treated seeds including control were sown in sand beds in size 4.6 x 0.7 m2 in a greenhouse at Horticulture Unit, UPMKB. Water was applied manually to maintain the soil moisture at field capacity as well as weed was manually controlled. The experiment was designed as 5 x 6 factorial in completely randomized design (CRD with three replications. Lethal dose 50 % of population (LD50 was assayed. Observation showed that germination percentage, plant height, survival percentage, root length, root weight and shoot dry weight decreased with increasing dose of gamma rays. The 800 Gy gamma ray dose had a profound effect on these variables perhaps due to injury the higher doses may have caused to the seeds of chili. This resulted in poor growth and development of chili seedlings. The LD50 for chili (survival percentage was estimated at 445 Gy. Loan contracts performance determines the profitability and stability of the financial institutions and screening the loan applications is a key process in minimizing credit risk. Before making any credit In general, higher gamma ray doses particularly 600 and 800 Gy had negative effect on the morphological characteristics of chili seedlings derived from irradiated seeds.

  12. Gamma Ray Tomographic Scan Method for Large Scale Industrial Plants

    International Nuclear Information System (INIS)

    The gamma ray tomography systems have been used to investigate a chemical process for last decade. There have been many cases of gamma ray tomography for laboratory scale work but not many cases for industrial scale work. Non-tomographic equipment with gamma-ray sources is often used in process diagnosis. Gamma radiography, gamma column scanning and the radioisotope tracer technique are examples of gamma ray application in industries. In spite of many outdoor non-gamma ray tomographic equipment, the most of gamma ray tomographic systems still remained as indoor equipment. But, as the gamma tomography has developed, the demand on gamma tomography for real scale plants also increased. To develop the industrial scale system, we introduced the gamma-ray tomographic system with fixed detectors and rotating source. The general system configuration is similar to 4th generation geometry. But the main effort has been made to actualize the instant installation of the system for real scale industrial plant. This work would be a first attempt to apply the 4th generation industrial gamma tomographic scanning by experimental method. The individual 0.5-inch NaI detector was used for gamma ray detection by configuring circular shape around industrial plant. This tomographic scan method can reduce mechanical complexity and require a much smaller space than a conventional CT. Those properties make it easy to get measurement data for a real scale plant

  13. Principles and techniques of gamma ray tracers

    International Nuclear Information System (INIS)

    Radioactive tracer techniques provide a very sensitive means of studying physical and chemical processes in a whole variety of different media. Some of the techniques and principles of radioactive tracers and their application to practical engineering systems are discussed. Information which has been found useful in the design of high temperature liquid sodium facilities employing radio-tracers, is presented. The report deals solely with the use of gamma-emitting species as the tracer. These find particular application for in-situ studies on engineering systems where the highly penetrating properties of gamma rays are needed for detection through strongly absorbent media such as stainless steel pepe walls. (author)

  14. Tolerance of edible flowers to gamma irradiation

    International Nuclear Information System (INIS)

    People have been eating flowers and using them in culinary creations for hundreds of years. Edible flowers are increasingly being used in meals as an ingredient in salads or garnish, entrees, drinks and desserts. The irradiation process is an alternative method that can be used in disinfestation of food and flowers, using doses that do not damage the product. The sensitivity of flowers to irradiation varies from species to species. In the present research was irradiated with doses up to 1 kGy some edible flowers to examine their physical tolerance to gamma-rays. Furthermore, high doses gamma irradiation causes petal withering, browning process and injury in edible flowers. (author)

  15. Beta/gamma test problems for ITS

    International Nuclear Information System (INIS)

    The Integrated Tiger Series of Coupled Electron/Photon Monte Carlo Transport Codes (ITS 3.0, PC Version) was used at Oak Ridge National Laboratory (ORNL) to compare with and extend the experimental findings of the beta/gamma response of selected health physics instruments. In order to assure that ITS gives correct results, several beta/gamma problems have been tested. ITS was used to simulate these problems numerically, and results for each were compared to the problem's experimental or analytical results. ITS successfully predicted the experimental or analytical results of all tested problems within the statistical uncertainty inherent in the Monte Carlo method

  16. Gamma Ray Bursts in the HAWC Era

    CERN Document Server

    Mészáros, Peter; Murase, Kohta; Fox, Derek; Gao, He; Senno, Nicholas

    2015-01-01

    Gamma-Ray Bursts are the most energetic explosions in the Universe, and are among the most promising for detecting multiple non-electromagnetic signals, including cosmic rays, high energy neutrinos and gravitational waves. The multi-GeV to TeV gamma-ray range of GRB could have significant contributions from hadronic interactions, mixed with more conventional leptonic contributions. This energy range is important for probing the source physics, including overall energetics, the shock parameters and the Lorentz factor. We discuss some of the latest observational and theoretical developments in the field.

  17. Gamma-Ray Bursts: Jets and Energetics

    CERN Document Server

    Frail, D A

    2003-01-01

    The relativistic outflows from gamma-ray bursts are now thought to be narrowly collimated into jets. After correcting for this jet geometry there is a remarkable constancy of both the energy radiated by the burst and the kinetic energy carried by the outflow. Gamma-ray bursts are still the most luminous explosions in the Universe, but they release energies that are comparable to supernovae. The diversity of cosmic explosions appears to be governed by the fraction of energy that is coupled to ultra-relativistic ejecta.

  18. Gamma Ray Astronomy with Magnetized Zevatrons

    OpenAIRE

    Armengaud, Eric; Sigl, Guenter; Miniati, Francesco

    2005-01-01

    Nearby sources of cosmic rays up to a ZeV(=10^21 eV) could be observed with a multi-messenger approach including secondary gamma-rays and neutrinos. If cosmic rays above ~10^18 eV are produced in magnetized environments such as galaxy clusters, the flux of secondary gamma-rays below ~1 TeV can be enhanced up to several orders of magnitudes compared to unmagnetized sources. A particular source of enhancement are synchrotron and cascade photons from e^+e^- pairs produced by protons from sources...

  19. Very high energy gamma ray astrophysics

    International Nuclear Information System (INIS)

    The Whipple Observatory High Resolution Camera will be used in a vigorous program of observations to search for new sources of very-high-energy gamma rays. In addition, a search for antimatter using the moon-earth system as an ion spectrometer will be begun. The first phase of GRANITE, the new 37-element 11-m camera, will be concluded with first light scheduled for September, 1991. The two cameras will operate in support of the Gamma Ray Observatory mission in the winter of 1991/2

  20. Fermi GBM Observations of Terrestrial Gamma Flashes

    Science.gov (United States)

    Wilson-Hodge, Colleen A.; Briggs, M. S.; Connaughton, V.; Fishman, G. J.; Bhat, P. N.; Paciesas, W. S.; Preece, R. D.; Kippen, R. M.; vonKienlin, A.; Dwyer, J. R.; Smith, D. M.; Holzworth, R.

    2010-01-01

    In its first two years of operation, the Fermi Gamma Ray Burst Monitor (GBM) has observed 79 Terrestrial Gamma Flashes (TGFs). The thick Bismuth Germanate (BGO) detectors are excellent for TGF spectroscopy, having a high probability of recording the full energy of an incident photon, spanning a broad energy range from 150 keV to 40 MeV, and recording a large number of photons per TGF. Correlations between GBM TGF triggers and lightning sferics detected with the World-Wide Lightning Location Network indicate that TGFs and lightning are simultaneous to within tens of microseconds.

  1. Gamma Radiation Effects on Peanut Skin Antioxidants

    OpenAIRE

    de Camargo, Adriano Costa; Vieira, Thais Maria Ferreira de Souza; Regitano-d’Arce, Marisa Aparecida Bismara; Calori-Domingues, Maria Antonia; Solange Guidolin CANNIATTI-BRAZACA

    2012-01-01

    Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to...

  2. Gamma ray spectrometer for Lunar Scout 2

    Science.gov (United States)

    Moss, C. E.; Burt, W. W.; Edwards, B. C.; Martin, R. A.; Nakano, George H.; Reedy, R. C.

    1993-01-01

    We review the current status of the Los Alamos program to develop a high-resolution gamma-ray spectrometer for the Lunar Scout-II mission, which is the second of two Space Exploration Initiative robotic precursor missions to study the Moon. This instrument will measure gamma rays in the energy range of approximately 0.1 - 10 MeV to determine the composition of the lunar surface. The instrument is a high-purity germanium crystal surrounded by an CsI anticoincidence shield and cooled by a split Stirling cycle cryocooler. It will provide the abundance of many elements over the entire lunar surface.

  3. New nuclear medicine gamma camera systems

    International Nuclear Information System (INIS)

    The acquisition of the Open E.CAM and DIACAM gamma cameras by Makati Medical Center is expected to enhance the capabilities of its nuclear medicine facilities. When used as an aid to diagnosis, nuclear medicine entails the introduction of a minute amount of radioactive material into the patient; thus, no reaction or side-effect is expected. When it reaches the particular target organ, depending on the radiopharmaceutical, a lesion will appear as a decrease (cold) area or increase (hot) area in the radioactive distribution as recorded byu the gamma cameras. Gamma camera images in slices or SPECT (Single Photon Emission Computer Tomography), increase the sensitivity and accuracy in detecting smaller and deeply seated lesions, which otherwise may not be detected in the regular single planar images. Due to the 'open' design of the equipment, claustrophobic patients will no longer feel enclosed during the procedure. These new gamma cameras yield improved resolution and superb image quality, and the higher photon sensitivity shortens imaging acquisition time. The E.CAM, which is the latest generation gamma camera, is featured by its variable angle dual-head system, the only one available in the Philipines, and the excellent choice for Myocardial Perfusion Imaging (MPI). From the usual 45 minutes, the acquisition time for gated SPECT imaging of the heart has now been remarkably reduced to 12 minutes. 'Gated' infers snap-shots of the heart in selected phases of its contraction and relaxation as triggered by ECG. The DIACAM is installed in a room with access outside the main entrance of the department, intended specially for bed-borne patients. Both systems are equipped with a network of high performance Macintosh ICOND acquisition and processing computers. Added to the hardware is the ICON processing software which allows total simultaneous acquisition and processing capabilities in the same operator's terminal. Video film and color printers are also provided. Together

  4. Cytotoxicity of mycotoxins after gamma irradiation

    OpenAIRE

    Calado, Thalita; Verde, S. Cabo; Abrunhosa, Luís; Fernández-Cruz, M.; Venâncio, Armando

    2015-01-01

    Due to the high toxicity of mycotoxins, many methods have been used to reduce or eliminate them from food and feed. Gamma radiation is one technique that has been investigated with some promising results in the degradation of mycotoxins from food commodities. The aims of this study were (i) to clarify the effect of gamma irradiation on aflatoxin B1 (AFB1), aflatoxin B2, aflatoxin G1, aflatoxin G2 and ochratoxin A (OTA); (ii) to evaluate the effect of the presence of water du...

  5. Effect of Gamma radiation on mycotoxins solutions

    OpenAIRE

    Calado, Thalita; António, Amilcar L.; Rodrigues, Paula; Cabo Verde, Sandra; Abrunhosa, Luís; Venâncio, Armando

    2013-01-01

    Due to the high toxicity of mycotoxins, many methods have been used to reduce or eliminate them from food and feed. Gamma radiation is one technique that has been investigated with some promising results in degradation of some mycotoxins from food. The aim of this study was to clarify the effect of gamma irradiation on aflatoxin B1 (AFB1) aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2), ochatoxin A (OTA) and zearelone (ZEA). The effect of the presence of moisture during the i...

  6. Effect of gamma radiation on mycotoxins solutions

    OpenAIRE

    Calado, Thalita; Antonio, Amilcar L.; Rodrigues, Paula; Cabo Verde, Sandra; Venâncio, Armando

    2013-01-01

    Due to the high toxicity of mycotoxins, many methods have been used to reduce or eliminate them from food and feed. Gamma radiation is one technique that has been investigated with some promising results in degradation of some mycotoxins from food. The aim of this study was to clarify the effect of gamma irradiation on aflatoxin B1 (AFB1) aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2), ochatoxin A (OTA) and zearelone (ZEA). The effect of the presence of moisture during the i...

  7. Tolerance of edible flowers to gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Amanda C.R.; Araujo, Michel M.; Costa, Helbert S.F.; Almeida, Mariana C.; Villavicencio, Anna Lucia C.H., E-mail: ackoike@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil)

    2011-07-01

    People have been eating flowers and using them in culinary creations for hundreds of years. Edible flowers are increasingly being used in meals as an ingredient in salads or garnish, entrees, drinks and desserts. The irradiation process is an alternative method that can be used in disinfestation of food and flowers, using doses that do not damage the product. The sensitivity of flowers to irradiation varies from species to species. In the present research was irradiated with doses up to 1 kGy some edible flowers to examine their physical tolerance to gamma-rays. Furthermore, high doses gamma irradiation causes petal withering, browning process and injury in edible flowers. (author)

  8. Gamma Knife Surgery in Trigeminal Neuralgia.

    Science.gov (United States)

    Wolf, Amparo; Kondziolka, Douglas

    2016-07-01

    Gamma knife surgery (GKS) represents a safe, effective, and relatively durable noninvasive treatment option for patients with trigeminal neuralgia (TN) and recurrent TN. By one year's time, 75% to 90% of patients will have obtained pain relief, defined as Barrow Neurological Institute grades I to IIIB. Similar rates have been demonstrated for patients undergoing a second GKS for recurrent TN. Predictors of durability of GKS in TN include type I TN, post-GKS Barrow Neurological Institute score, and the presence of post-Gamma Knife facial numbness. PMID:27324996

  9. A Shotgun Model for $\\gamma$ Ray Bursts

    CERN Document Server

    Heinz, S

    1999-01-01

    We propose that gamma ray bursts (GRBs) are produced by a shower of heavy blobs running into circumstellar material at highly relativistic speeds. The gamma ray emission is produced in the shocks these bullets drive into the surrounding medium. The short term variability seen in GRBs is set by the slowing-down time of the bullets while the overall duration of the burst is set by the lifetime of the central engine. A requirement of this model is that the ambient medium be dense, consistent with a strong stellar wind. In contrast to other external shock scenarios, the efficiency of the shock can be close to unity.

  10. Performance assessment of gamma cameras. Part 1

    International Nuclear Information System (INIS)

    The Dept. of Health and Social Security and the Scottish Home and Health Dept. has sponsored a programme of measurements of the important performance characteristics of 15 leading types of gamma cameras providing a routine radionuclide imaging service in hospitals throughout the UK. Measurements have been made of intrinsic resolution, system resolution, non-uniformity, spatial distortion, count rate performance, sensitivity, energy resolution and shield leakage. The main aim of this performance assessment was to provide sound information to the NHS to ease the task of those responsible for the purchase of gamma cameras. (U.K.)

  11. Gamma rays induced variation in Plantago ovata

    International Nuclear Information System (INIS)

    Plantago ovata Fork., a medicinal herb, requires improvement in seed yield to meet would demand for its seed husk. Mutation breeding has been attempted on account of narrow genetic base of the crop. The mutagen, gamma rays from 60Co sources was tried for its effect on various phenotypic traits, including those related to seed yield. Studies indicate that P. ovata is radio-resistant. Gamma rays also induce alteration in mean and variance of yield related characters which can be exploited to select superior genotypes in this conservative crop

  12. An automatic sample changer for gamma spectrometry

    International Nuclear Information System (INIS)

    An automatic sample changer for gamma spectrometry is described which is designed for large-volume, low radioactivity environmental samples of various sizes up to maximum dimensions 100 mm diameter x 60 mm high. The sample changer is suitable for use with most existing gamma spectrometry systems which utilize GeLi or NaI detectors in vertical mode, in conjunction with a pulse height analyzer having auto-cycle and suitable data output facilities; it is linked to a Nuclear Data ND 6620 computer-based analysis system. (U.K.)

  13. Observation of J/psi --> 3 gamma

    CERN Document Server

    Adams, G S; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Reed, J; Briere, R A; Ferguson, T; Ma, J S Y; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hunt, J M; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Ledoux, J; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A G; Libby, J; Powell, A; Wilkinson, G; Ecklund, K M; Love, W; Savinov, V; Méndez, H; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B

    2008-01-01

    We report the first observation of the decay J/psi --> 3 gamma. The signal has a statistical significance of 6 sigma and corresponds to a branching fraction of B(J/psi --> 3 gamma) = (1.2 +- 0.3 +- 0.2) x 10^-5, in which the errors are statistical and systematic, respectively. The measurement uses psi(2S) --> pi+ pi- J/psi events acquired with the CLEO-c detector operating at the CESR e+e- collider.

  14. Residual water treatment for gamma radiation

    International Nuclear Information System (INIS)

    The treatment of residual water by means of gamma radiation for its use in agricultural irrigation is evaluated. Measurements of physical, chemical, biological and microbiological contamination indicators were performed. For that, samples from the treatment center of residual water of San Juan de Miraflores were irradiated up to a 52.5 kGy dose. The study concludes that gamma radiation is effective to remove parasites and bacteria, but not for removal of the organic and inorganic matter. (author). 15 refs., 3 tabs., 4 figs

  15. Sewage Water Treatment by Gamma Irradiation

    International Nuclear Information System (INIS)

    This study indicates that Gamma irradiation could be the solution for raising the standards of disinfection in waste water of Damascus city up to the international standards, when samples of the inlet of the planet was irradiated with Gamma radiation at dose rate of 3.4 KGy./hr The radiation sensitivity of total micro-organisms, fungi, and pathogenic bacteria was 0.316, 0.318 , 0.306 KGy respectively Also the results showed the absence of Ascaris Lumbricoides ova which permit reusing the recycled waste water in irrigation safely. (authors)

  16. Nuclear forensics using gamma-ray spectroscopy

    CERN Document Server

    Norman, Eric B

    2016-01-01

    Much of George Dracoulis's research career was devoted to utilizing gamma-ray spectroscopy in fundamental studies in nuclear physics. This same technology is useful in a wide range of applications in the area of nuclear forensics. Over the past several years, our research group has made use of both high- and low- resolution gamma ray spectrometers to: identify the first sample of plutonium large enough to be weighed; determine the yield of the Trinity nuclear explosion; measure fission fragment yields as a function of target nucleus and neutron energy; and observe fallout in the U. S. from the Fukushima nuclear reactor accident.

  17. Gamma-ray surveys in uranium exploration

    International Nuclear Information System (INIS)

    This report is intended to provide newcomers to uranium exploration with an up-to-date statement of the principal factors to be considered in planning and using gamma-ray surveys. Since the report incorporates the results of recent research, and since its preparation was influenced by the cumulative experience of its contributors, it should also be useful to those who already have some knowledge of radioactivity surveys and methods. The intention is that the information and explanations given in the report will make it possible for gamma-ray surveys to be used in the most efficient way for a given exploration task

  18. Status of the Milagro $\\gamma$ Ray Observatory

    CERN Document Server

    Atkins, R; Berley, D; Chen, M L; Coyne, D G; Delay, R S; Dingus, B L; Dorfan, D E; Ellsworth, R W; Evans, D; Falcone, A D; Fleysher, L; Fleysher, R; Gisler, G; Goodman, J A; Haines, T J; Hoffman, C M; Hugenberger, S; Kelley, L A; Leonor, I; Macri, J R; McConnell, M; McCullough, J F; McEnery, J E; Miller, R S; Mincer, A I; Morales, M F; Némethy, P; Ryan, J M; Schneider, M; Shen, B; Shoup, A L; Sinnis, G; Smith, A J; Sullivan, G W; Thompson, T N; Tümer, T O; Wang, K; Wascko, M O; Westerhoff, S; Williams, D A; Yang, T; Yodh, G B

    2001-01-01

    The Milagro Gamma Ray Observatory is the world's first large-area water Cherenkov detector capable of continuously monitoring the sky at TeV energies. Located in northern New Mexico, Milagro will perform an all sky survey of the Northern Hemisphere at energies between ~250 GeV and 50 TeV. With a high duty cycle, large detector area (~5000 square meters), and a wide field-of-view (~1 sr), Milagro is uniquely capable of searching for transient and DC sources of high-energy gamma-ray emission. Milagro has been operating since February, 1999. The current status of the Milagro Observatory and initial results will be discussed.

  19. Storage ability of gamma irradiated mango fruits

    International Nuclear Information System (INIS)

    Extension of shelf-life have been achieved by many methods. the most modern one is using gamma irradiation as a promising technology for the developing nations. The aim of this investigation is to study the effects of gamma irradiation either alone or in combination with Alar or Benlate on 'Hindi Be Senara' mature green fruits and also to determine the optimum treatment and maximum extension in shelf - life. Mature-green 'Hindi be sinara' mango fruits were taken from trees planted in commercial orchard in 'kerdasa'Giza

  20. New Precise Measurements of the $\\Xi^{0} \\to \\Lambda \\gamma$ and $\\Xi^{0} \\to \\Sigma^{0}\\gamma$ Decay Asymmetries

    CERN Document Server

    Batley, J R; Lazzeroni, C; Munday, D J; Patel, M; Slater, M W; Wotton, S A; Arcidiacono, R; Bocquet, G; Ceccucci, A; Cundy, D; Doble, N; Falaleev, V; Gatignon, L; Gonidec, A; Grafstrom, P; Kubischta, W; Mikulec, I; Norton, A; Panzer-Steindel, B; Rubin, P; Wahl, H; Goudzovski, E; Hristov, P; Kekelidze, V; Litov, L; Madigozhin, D; Molokanova, N; Potrebenikov, Yu; Stoynev, S; Zinchenko, A; Monnier, E; Swallow, E; Winston, R; Sacco, R; Walker, A; Baldini, W; Gianoli, A; Dalpiaz, P; Frabetti, P L; Martini, M; Petrucci, F; Savrie, M; Scarpa, M; Calvetti, M; Collazuol, G; Iacopini, E; Ruggiero, G; Bizzeti, A; Lenti, M; Veltri, M; Behler, M; Eppard, K; Eppard, M; Hirstius, A; Kleinknecht, K; Koch, U; Marouelli, P; Masetti, L; Moosbrugger, U; Morales-Morales, C; Peters, A; Wanke, R; Winhart, A; Dabrowski, A; Fonseca Martin, T; Velasco, M; Cenci, P; Lubrano, P; Pepe, M; Anzivino, G; Imbergamo, E; Lamanna, G; Michetti, A; Nappi, A; Petrucci, M C; Piccini, M; Valdata, M; Cerri, C; Fantechi, R; Costantini, F; Fiorini, L; Giudici, S; Pierazzini, G; Sozzi, M; Mannelli, I; Cheshkov, C; Cheze, J B; De Beer, M; Debu, P; Gouge, G; Marel, G; Mazzucato, E; Peyaud, B; Vallage, B; Holder, M; Maier, A; Ziolkowski, M; Biino, C; Cartiglia, N; Marchetto, F; Pastrone, N; Clemencic, M; Goy Lopez, S; Menichetti, E; Wislicki, W; Dibon, H; Jeitler, M; Markytan, M; Neuhofer, G; Widhalm, L

    2010-01-01

    The decay asymmetries of the weak radiative Hyperon decays $\\Xi^{0}\\to \\Lambda \\gamma$ and $\\Xi^{0} \\to \\Sigma^{0}\\gamma$ have been measured with high precision using data of the NA48/1 experiment at CERN. From about 52000 $\\Xi^{0}\\to \\Lambda \\gamma$ and 15000 $\\Xi^{0} \\to \\Sigma^{0}\\gamma$ decays, we obtain for the decay asymmetries $\\alpha_{\\Xi^{0}\\to \\Lambda\\gamma}$ = -0.704 +- 0.019$_{stat}$ +- 0.064$_{syst}$ and $\\alpha_{\\Xi^{0}\\to \\Sigma^{0}\\gamma}$ = -0.729 +- 0.030$_{stat}$ +- 0.076$_{syst}$, respectively. These results are in good agreement with previous experiments, but more precise.