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Sample records for cavity preparation efeitos

  1. Dissipative preparation of entanglement in optical cavities

    DEFF Research Database (Denmark)

    Kastoryano, Michael James; Reiter, Florentin; Sørensen, Anders Søndberg

    2011-01-01

    We propose a novel scheme for the preparation of a maximally entangled state of two atoms in an optical cavity. Starting from an arbitrary initial state, a singlet state is prepared as the unique fixed point of a dissipative quantum dynamical process. In our scheme, cavity decay is no longer...

  2. Histopathological study of the effects of low-intensity laser irradiation ({lambda}=650 nm) on dental pulp tissue after cavity preparation; Estudo histopatologico dos efeitos da irradiacao laser em baixa intensidade ({lambda}=650nm) em tecido pulpar apos preparo cavitario

    Energy Technology Data Exchange (ETDEWEB)

    Bertella, Claudio

    2001-07-01

    The purpose of this study was to evaluate (in vivo) the effects of low-intensity Arsenide Gallium Aluminium laser application post-cavity preparation class 1. Six patients with bilateral pre-molars and molars indicated to extraction for orthodontics aim were selected. Four samples of these teeth underwent cavity preparation with deep from medium to high and two samples underwent cavity preparation from high to pulp expositions. The samples were constituted of two teeth of the same patient and received different treatments. One of the teeth underwent laser exposition and the other one was maintained as control, before restorative procedure with polycarboxylate cement. A diode laser ({lambda}=650 nm), output power 30 mW and fluencies of 1,8 J/cm{sup 2} and 2,7 J/cm{sup 2} in pre-molars and molars, respectively, was used for irradiation with repetition rate of 18 Hz in interrupted continuous wave mode. After seven days, the teeth were extracted and processed histologically with HE to verify morphological changes in the pulpy tissue. The four samples, which cavity preparation and restorative material were not in contact with the pulp, did not show histological differences between irradiated and non-irradiated teeth. Both of them presented the same characteristics of normality. The two samples with exposed pulpy tissue showed different results. The irradiated teeth presented no or slight inflammatory signs when compared to the control samples, which showed abscess in the coronary pulp interior and intense inflammatory infiltrated. These results suggest that the laser irradiation can be used as a therapeutic modality in clinical trials, in the conditions employed in this study. (author)

  3. Cavity preparation machine for the standardization of in vitro preparations

    Directory of Open Access Journals (Sweden)

    Carlos José Soares

    2008-09-01

    Full Text Available Several in vitro studies employ the confection of cavity preparations that are difficult to standardize by means of manual high speed handpieces. This study presents the development of a cavity preparation machine designed to standardize in vitro cavity preparations. A metal base of 25 mm x 25 mm x 4 mm (length x width x height was coupled to a small mobile table which was designed to be able to move by means of two precision micrometers (0.01-mm accuracy in the horizontal directions (right-left, and back-front. A high speed handpiece was coupled to a metallic connecting rod which had an accurate dial indicator enabling control of the vertical movement. The high speed handpiece is also able to move 180° around its longitudinal axis and 360° around its transversal axis. The suggested cavity preparation machine precisely helps in the standardization of cavity preparations for in vitro studies.

  4. Cavity preparation machine for the standardization of in vitro preparations.

    Science.gov (United States)

    Soares, Carlos José; Fonseca, Rodrigo Borges; Gomide, Henner Alberto; Correr-Sobrinho, Lourenço

    2008-01-01

    Several in vitro studies employ the confection of cavity preparations that are difficult to standardize by means of manual high speed handpieces. This study presents the development of a cavity preparation machine designed to standardize in vitro cavity preparations. A metal base of 25 mm x 25 mm x 4 mm (length x width x height) was coupled to a small mobile table which was designed to be able to move by means of two precision micrometers (0.01-mm accuracy) in the horizontal directions (right-left, and back-front). A high speed handpiece was coupled to a metallic connecting rod which had an accurate dial indicator enabling control of the vertical movement. The high speed handpiece is also able to move 180 degrees around its longitudinal axis and 360 degrees around its transversal axis. The suggested cavity preparation machine precisely helps in the standardization of cavity preparations for in vitro studies. PMID:18949317

  5. Preparation and handling of superconducting RF cavities

    International Nuclear Information System (INIS)

    The present paper outlines the recent preparation methods for superconducting cavities used in various laboratories and universities, and reports the problems of the cavity fabrication at KEK as an example of mass production. Preparation and handling are first addressed, focusing on material, fabrication, surface treatment, rinsing, clean environment, and heat treatment. Cavity production at KEK is then described, centering on defects on the surface and clean environments. Field gradients of more than 20 MV/m have been obtained by 1.5-3 GHz single cavities, for multi-cell cavities Eacc of 10 MV/m are available at any frequency range. The successful construction of thirty-two cavities for TRISTAN at KEK is due to the careful checking of the surface and quality control of all processes against the surface defects and contaminations. Eacc of 5 MV/m has been achieved by 94 % of the TRISTAN cavities at the first cold test, but 6 % of them had to be reworked because of the surface defects. These defects could not be detected by an X-ray photograph or visual inspections during the fabrication processes. (N.K.)

  6. Preparation of the W state via cavity QED

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jin; YE Liu

    2004-01-01

    A scheme for preparation of the tripartite W state via cavity quantum electrodynamics is presented in this paper. And the scheme can be generalized to prepare the n-atom W states. The second part of this paper shows how to prepare n-cavity W states. All cavities involved are initially in the vacuum states, thus the requirement on the quality factor of the cavities is greatly loosened.

  7. Ultrasonic Abrasion: An Alternative for Cavity Preparation

    Directory of Open Access Journals (Sweden)

    Áurea Simone Barrôso VIEIRA

    2007-05-01

    Full Text Available Introduction: Restorative dentistry aims to repair damages caused by caries disease. Along the years, researchers have developed effective and less invasive methods with the goal of preserving the teeth from caries destruction. Therefore, the improvement of scientific knowledge, auxiliary diagnostic systems, dental materials, and new instruments has changed the approaches and treatments in this field. In addition to conservative removal of carious tissue, patient’s comfort has also become a concern in modern dentistry.Purpose: Considering that ultrasonic abrasion has attracted great interest of dental professionals, this article discusses an alternative technique for cavity preparation by literature review, addressing its indications, contra-indications, advantages and limitations compared to the conventional high-speed method.Conclusion: There are not many studies on this subject. The available studies have demonstrated several qualities of the ultrasonic abrasion system, but some aspects remain unclear. Therefore, it is important to highlight that laboratorial and clinical studies in primary/permanent teeth should be conducted to elucidate questionable issues, such as time of cavity preparation, topography, presence of smear layer and microleakage, in order to offer safety to the extensive use of this new technology for both the professional and the patient. In this context, the dentist should always be attentive to innovations referring to minimally invasive techniques.

  8. Preparation of W state in resonant bimodal cavity quantum electrodynamics

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A scheme is proposed for generating entangled W states with four cavity modes. In this scheme, we send a Ⅴ-type three-level atom through two identical two-mode cavities in succession. After the atom exits from the second cavity,the four cavity modes are prepared in the W state. On the other hand we can obtain three-atom W states by sending three Ⅴ-type three-level atoms through a two-mode cavity in turn. The present scheme does not require conditional measurement, and it is easily generalized to preparing 2n-mode W states and n-atom W states.

  9. Effects of low-intensity GaAlAs laser radiation ({lambda}=660 nm) on dentine-pulp interface after class I cavity preparation; Efeitos da radiacao laser GaAlAs ({lambda}=660 nm) em baixa intensidade na interface dentina-polpa pos-preparo cavitario classe 1

    Energy Technology Data Exchange (ETDEWEB)

    Godoy, Bruno Miranda

    2003-07-01

    The aim of this study was to investigate the effects of low-intensity irradiation with GaAlAs laser (red emission) on the ultrastructure of dentine-pulp interface after conventionally prepared class I cavity preparation. Two patients with 8 premolars for extraction indicated for orthodontic reasons. Class I cavities were prepared in these teeth that were then divided into two groups. The first group received a treatment with laser with continuous emission, {lambda}=660 nm, with maximum power output of 30 mW. The dosimetry applied was of approximately 2J/cm{sup 2}, directly and perpendicularly into the cavity in only one section. After the irradiation, the cavities were filled with composite resin. The second group received the same treatment, except by the laser therapy. Twenty-eight days after the preparation, the teeth were extracted and were processed for transmission electron microscopy analysis. Two sound teeth, without any preparation, were also studied. The irradiated group presented odontoblastic processes in higher contact with the extracellular matrix and the collagen fibers appeared more aggregated and organized than those of control group. These results were also observed in the healthy-teeth. Thus, we suggest that laser irradiation accelerates the recovery of the dental structures involved in the cavity preparation at the pre-dentine level. (author)

  10. Strong-Driving-Assisted Probabilistic State Preparation in Cavity QED

    Institute of Scientific and Technical Information of China (English)

    YANG Zhen-Biao

    2006-01-01

    An alternative scheme is proposed for preparing the superpositions of coherent states with controllable weighting factors along a straight line for a cavity field. The scheme is based on the interaction of a single-mode cavity field with a resonant two-level atom driven by a strong classical field. It is in contrast to the previous methods used in cavity QED of injecting a coherent state into a cavity via a microwave source. In the scheme, the interaction between the cavity mode and atoms is fully resonant, thus the required interaction time is greatly shortened. Moreover, the present scheme requires smaller numbers of operations. In view of decoherence, a reduction of interaction time and numbers of operations for the state preparation is very important for experimental implementation of quantum state engineering.

  11. Preparation of Macroscopic Quantum Superposition States of Cavity Modes Using rf-SQUIDs in a Cavity

    Institute of Scientific and Technical Information of China (English)

    WANG Bo

    2008-01-01

    We propose a potential scheme of preparing Schrodinger-cat state of the cavity mode by placing an rf-superconducting quantum interference device (rf-SQUID) in a single-mode microwave cavity. By properly adjusting the detuning and the strength regarding the radiation fields, we show how to generate single-mode Schrodinger-eat state. Generalizing this method we discuss the generation of the engtangled coherent states. The experimental feasibility of our scheme is discussed under consideration of the cavity decay.

  12. A Scheme for Preparation of W-Type Entangled Coherent State of Three-Cavity Fields

    Institute of Scientific and Technical Information of China (English)

    YUAN Chun-Hua; OU Yong-Cheng; ZHANG Zhi-Ming

    2006-01-01

    @@ We present an experimental scheme to prepare the three-cavity W-type entangled coherent state in the context of dispersive cavity quantum electrodynamics. The discussion of our scheme indicates that it can be realized by current technology.

  13. Preparation of Genuinely Entangled Six-Atom State via Cavity Quantum Electrodynamics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen; LIU Yi-Min; YIN Xiao-Feng; ZHANG Zhan-Jun

    2011-01-01

    A cavity quantum electrodynamics scheme for preparing a genuinely entangled state [A. Borras, et al., J. Phys. A 40 (2007) 13407] on six two-level atoms is proposed. In the scheme, the atom-cavity detuning is much bigger than the atom-cavity coupling strength and the necessary preparation time is much shorter than the Rydberg-atom lifespan. Hence the scheme has two distinct features, i.e., insensitive to the cavity decay and the atom radiation.

  14. Teleportation of Atomic States via Cavity QED for a Cavity Prepared in a Superposition of Zero and One Fock States

    CERN Document Server

    Guerra, E S

    2004-01-01

    In this article we discuss two schemes of teleportation of atomic states. In the first scheme we consider atoms in a three-level cascade configuration and in the second scheme we consider atoms in a three-level lambda configuration. The experimental realization proposed makes use of cavity Quatum Electrodynamics involving the interaction of Rydberg atoms with a micromaser cavity prepared in a state $|\\psi >_{C}=(|0> +|1>)/\\sqrt{2}$

  15. Impairment of an atrophic mandible by preparation of the implant cavity: a biomechanical study.

    Science.gov (United States)

    Steiner, Timm; Torsiglieri, Tobias; Rau, Andrea; Möhlhenrich, Stephan C; Eichhorn, Stefan; Grohmann, Isabella; Deppe, Herbert; Hölzle, Frank; Raith, Stefan

    2016-07-01

    An important complication during insertion of implants in atrophic mandibles is the fracture that can be induced by preparation of the cavity. We designed this study to identify which configuration of cavities in the interforaminal region was the least likely to fracture. An electromechanical testing machine was used to measure breaking loads of specifically-designed synthetic models of atrophic mandibles. The implant cavities correlated with the common clinical patterns. Intact atrophied synthetic mandibles broke at a mean (SD) load of 729.48 (59.94) N (control group). Models with four different configurations of cavities fractured as follows: two short, wide cavities (8 x 4.2mm) at a mean (SD) load of 569.17 (67.7) N; two long, thin cavities (15 x2.8mm) at a load of 563.40 (62.0) N; four short, wide cavities (8 x 4.2mm) at a load of 667.01 (71.89) N; and four long, thin cavities (15 x 2.8mm) at a load of 409.50 (43.61) N. Biomechanical findings showed that there was a greater risk of fracture of atrophic mandibular models in long, thin implant cavities with more preparation sites. Each cavity prepared for an implant increased the risk of fracture in an atrophic mandible. The risk of fracture is greatest with long, thin cavities. PMID:27068851

  16. Efficient scheme for preparation of the multi-atom W state via cavity quantum electrodynamics

    Institute of Scientific and Technical Information of China (English)

    Zhang Jin; Ye Liu

    2004-01-01

    We present an efficient scheme for preparation of the multi-atom W state via cavity quantum electrodynamics.Involved in this scheme are n identical two-level atoms and a single-mode cavity field. Discussion indicates that this scheme can be realized easily by current technologies.

  17. Cavity-based single atom preparation and high-fidelity hyperfine state readout

    OpenAIRE

    Gehr R.; Volz J.; Dubois G.; Steinmetz T.; Colombe Y.; Lev B.L.; Long R.; Esteve J.; Reichel J.

    2010-01-01

    We prepare and detect the hyperfine state of a single 87Rb atom coupled to a fiber-based high finesse cavity on an atom chip. The atom is extracted from a Bose-Einstein condensate and trapped at the maximum of the cavity field, resulting in a reproducibly strong atom-cavity coupling. We use the cavity reflection and transmission signal to infer the atomic hyperfine state with a fidelity exceeding 99.92% in a read-out time of 100 microseconds. The atom is still trapped after detection.

  18. Preparation and Testing of the SRF Cavities for the CEBAF 12 GeV Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Reilly, A. V.; Bass, T.; Burrill, A.; Davis, G. K.; Marhauser, F.; Reece, C. E.; Stirbet, M.

    2011-07-01

    Eighty new 7-cell, low-loss cell-shaped cavities are required for the CEBAF 12 GeV Upgrade project. In addition to ten pre-production units fabricated at JLab, the full set of commercially-produced cavities have been delivered. An efficient processing routine, which includes a controlled 30 micron electropolish, has been established to transform these cavities into qualified 8-cavity strings. This work began in 2010 and will run through the end of 2011. The realized cavity performance consistently exceeds project requirements and also the maximum useful gradient in CEBAF: 25 MV/m. We will describe the cavity processing and preparation protocols and summarize test results obtained to date.

  19. Preparation and Testing of the SRF Cavities for the CEBAF 12 GeV Upgrade

    International Nuclear Information System (INIS)

    Eighty new 7-cell, low-loss cell-shaped cavities are required for the CEBAF 12 GeV Upgrade project. In addition to ten pre-production units fabricated at JLab, the full set of commercially-produced cavities have been delivered. An efficient processing routine, which includes a controlled 30 micron electropolish, has been established to transform these cavities into qualified 8-cavity strings. This work began in 2010 and will run through the end of 2011. The realized cavity performance consistently exceeds project requirements and also the maximum useful gradient in CEBAF: 25 MV/m. We will describe the cavity processing and preparation protocols and summarize test results obtained to date

  20. Cavities

    Science.gov (United States)

    ... the bacteria produce acids that cause decay. Tooth pain occurs after decay reaches the inside of the tooth. Dentists can detect cavities by examining the teeth and taking x-rays periodically. Good oral hygiene and regular dental care plus a healthy diet can help prevent cavities. ...

  1. Preparation and handling of surfaces for superconducting radio frequency cavities

    International Nuclear Information System (INIS)

    Fortunately, surface treatment for s.c. cavities knows only one simple rule. If one observes this rule strictly one will be successful, if not, one will fail! The rule is CLEANLINESS. This means: clean material (high purity niobium without inclusions), clean (analytical grade) polishing chemicals and solvents, ultraclean (semiconductor grade) rinsing water, ultraclean (class 100) assembly environment. In general, if one applies the same working practice as the semiconductor industry, one will produce surfaces that are less clean than silicon wafers, due to the shape of the cavity (an inner surface is much more difficult to clean than a flat wafer); due to its size and due to the material (niobium is hydrophilic which makes the water with all the dirt in it stick to the surface). 9 references

  2. Preparation of Multi—Atom Entangled States with a Single Cavity in a Thermal State

    Institute of Scientific and Technical Information of China (English)

    ZHENGShi-Biao

    2002-01-01

    A scheme is suggested for the generation of multi-atom maximally entangled states with a cavity in a thermal state,In this scheme several appropriately prepared two-level atoms are simultaneously sent through the nonresonant cavity.We divide the whole atom-cavity interaction time into two equal parts.At the end of the first part a π pulse is applied to the atome using a classical field.Then the photon-number-dependent shifts on the atomic states are cancelled and the atomic system finally evoloves to a maximally entangled state.

  3. Implementation of quantum controlled phase gate and preparation of multiparticle entanglement in cavity QED

    Institute of Scientific and Technical Information of China (English)

    Wu Xi; Chen Zhi-Hua; Zhang Yong; Chen Yue-Hua; Ye Ming-Yong; Lin Xiu-Min

    2011-01-01

    Schemes are presented for realizing quantum controlled phase gate and preparing an N-qubit W-like state, which are based on the large-detuned interaction among three-state atoms, dual-mode cavity and a classical pulse. In particular, a class of W states that can be used for perfect teleportation and superdense coding is generated by only one step.Compared with the previous schemes, cavity decay is largely suppressed because the cavity is only virtually excited and always in the vacuum state and the atomic spontaneous emission is strongly restrained due to a large atom-field detuning.

  4. Preparation of Entanglement of Atoms and of Photons via Cavity Input–Output Process

    International Nuclear Information System (INIS)

    We propose a method to prepare multipartite entangled states such as cluster states and graph states based on the cavity input–output process and single photon measurement. Two quantum gates, a controlled phase gate and a fusion gate between two atoms trapped in respective cavities, are proposed to prepare atomic cluster states and graph states with one and two dimensions. We also introduce a scheme that can generate an arbitrary multipartite photon cluster state which uses two coherent states as a qubit basis. (general)

  5. Microleakage in conservative cavities varying the preparation method and surface treatment

    Directory of Open Access Journals (Sweden)

    Juliana Abdallah Atoui

    2010-08-01

    Full Text Available OBJECTIVE: To assess microleakage in conservative class V cavities prepared with aluminum-oxide air abrasion or turbine and restored with self-etching or etch-and-rinse adhesive systems. Materials and Methods: Forty premolars were randomly assigned to 4 groups (I and II: air abrasion; III and IV: turbine and class V cavities were prepared on the buccal surfaces. Conditioning approaches were: groups I/III - 37% phosphoric acid; groups II/IV - self-priming etchant (Tyrian-SPE. Cavities were restored with One Step Plus/Filtek Z250. After finishing, specimens were thermocycled, immersed in 50% silver nitrate, and serially sectioned. Microleakage at the occlusal and cervical interfaces was measured in mm and calculated by a software. Data were subjected to ANOVA and Tukey's test (α=0.05. RESULTS: Marginal seal provided by air abrasion was similar to high-speed handpiece, except for group I. There was SIGNIFICANT difference between enamel and dentin/cementum margins for to group I and II: air abrasion. The etch-and-rinse adhesive system promoted a better marginal seal. At enamel and dentin/cementum margins, the highest microleakage values were found in cavities treated with the self-etching adhesive system. At dentin/cementum margins, high-speed handpiece preparations associated with etch-and-rinse system provided the least dye penetration. CONCLUSION: Marginal seal of cavities prepared with aluminum-oxide air abrasion was different from that of conventionally prepared cavities, and the etch-and-rinse system promoted higher marginal seal at both enamel and dentin margins.

  6. Comparison of Dentin Permeability After Tooth Cavity Preparation with Diamond Bur and Er:YAG Laser

    Science.gov (United States)

    Hasani Tabatabaei, Masoumeh; Shirmohammadi, Sara; Yasini, Esmaeil; Mirzaei, Mansoureh; Arami, Sakineh; Kermanshah, Hamid; Ranjbar Omrani, Ladan; Alimi, Azar; Chiniforush, Nasim; Nakhostin, Afrooz

    2015-01-01

    Objectives: The aim of this study was to compare the permeability of dentin after using diamond bur and Er:YAG laser. Materials and Methods: Seventy-two recently extracted, intact, and restoration-free human permanent molars were used in this study. The samples were randomly divided into three groups of 24 each and class I cavities were prepared as follows. Group 1: High speed diamond bur with air and water spray. Group 2: Er:YAG laser. Group 3: Er:YAG laser followed by additional sub-ablative laser treatment. Each group consisted of two subgroups with different cavity depths of 2mm and 4mm. The entire cavity floor was in dentin. Two samples from each subgroup were observed under scanning electron microscope (SEM). The external surfaces of other samples were covered with nail varnish (except the prepared cavity) and immersed in 0.5% methylene blue solution for 48 hours. After irrigation of samples with water, they were sectioned in bucco-lingual direction. Then, the samples were evaluated under a stereomicroscope at ×160 magnification. The data were analyzed using two-way ANOVA and Tukey’s HSD test. Results: Two-way ANOVA showed significant difference in permeability between groups 2 and 3 (laser groups with and without further treatment) and group 1 (bur group). The highest permeability was seen in the group 1. There was no significant difference in dentin permeability between groups 2 and 3 and no significant difference was observed between different depths (2mm and 4mm). Conclusion: Cavities prepared by laser have less dentin permeability than cavities prepared by diamond bur. PMID:27148373

  7. Preparation of Multi-Atom Entangled States with a Single Cavity in a Thermal State

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shi-Biao

    2002-01-01

    A scheme is suggested for the generation of multi-atom maximally entangled states with a cavity in a thermalstate. In this scheme several appropriately prepared two-level atoms are simultaneously sent through the nonresonantcavity. We divide the whole atom-cavity interaction time into two equal parts. At the end of the first part a π pulse isapplied to the atoms using a classical field. Then the photon-number-dependent shifts on the atomic states are cancelledand the atomic system finally evolves to a maximally entangled state.

  8. Temperature variation on root surface with three root-end cavity preparation techniques

    Directory of Open Access Journals (Sweden)

    Bodrumlu Emre

    2013-01-01

    Full Text Available Introduction. Thermal changes can occur on the external root surface when root-end cavity preparation is performed, which may damage periodontal ligament cells and alveolar bone. Objective. The purpose of this study was to evaluate the temperature changes during preparation of the root-end cavities at 1 and 3 mm to the sectioned apical root surfaces when either tungsten carbide round bur, diamond round bur or ultrasonic diamond tip was used. Methods. Root-end resection was performed at 90° to the long axis of the root, 3 mm from the apex. Specimens were randomly divided into three groups of 12 teeth each for three different root-end cavity preparation techniques to be used, i.e. tungsten carbide bur, diamond bur and ultrasonic diamond retro tip. Thermocouples were used to measure temperature changes at 1 mm (T1 and 3 mm (T2 to the cutting plane during the preparations. Results. For T1, the lowest and the highest mean temperature increases of 3.53°C and 4.34°C were recorded for the carbide and diamond burs, respectively. For T2, the lowest and the highest mean temperature increases of 2.62°C and 4.39°C where recorded for the carbide and diamond burs, respectively. The mean temperatures with the ultrasonic tip were 3.68 and 3.04 ºC at T1 and T2 region, respectively. For root-end preparation, the ultrasonic preparation technique took the shortest preparation time (10.25 sec and the diamond bur took the longest time (28.17 sec. Conclusion. Ultrasonic retro tips and burs caused temperature to rise from 2.62° to 4.39°C, and these rises were within safety levels.

  9. Efeitos do sulfato de bário na cavidade pleural de ratos Effects of barium sulphate in rats pleural cavity

    Directory of Open Access Journals (Sweden)

    Giovanni Antonio Marsico

    2001-10-01

    Full Text Available OBJETIVO: Avaliar os efeitos do sulfato de bário na cavidade pleural de ratos. MÉTODO: Foram avaliados, experimentalmente, os efeitos do sulfato de bário a 100% na cavidade pleural de 43 ratos. Sob anestesia inalatória com éter, foi realizada injeção de contraste radiológico (1ml na cavidade pleural direita após punção com agulha romba pela via subxifóide. Os ratos, divididos em três grupos, foram mortos em câmara fechada com éter, após 24h (13 ratos, 48h (16 ratos e 21 dias (14 ratos, respectivamente. Através de esternotomia longitudinal e laparotomia alta, foram retiradas a pleura parietal e visceral, juntas com o gradil costal e o pulmão direito. No grupo-controle, de 22 ratos, foi injetado 1ml de soro fisiológico a 0,9% na cavidade pleural direita. RESULTADOS: Não houve mortes entre os 43 ratos em que foi injetado sulfato de bário e no grupo-controle. As alterações encontradas na cavidade pleural dos grupos injetados com sulfato de bário e mortos com 24h e 48h foram semelhantes: leve e difusa hiperemia na pleura parietal, sulfato de bário livre, derrame pleural inflamatório com predomínio de polimorfonucleares; macrófagos na pleura fagocitando sulfato de bário e pleura com infiltrado predominantemente polimorfonuclear. Com 21 dias, o sulfato de bário estava localizado e bloqueado na região retroesternal e havia formação de sínfises pleurais intensas. No exame histopatológico das pleuras havia grande quantidade de macrófagos repletos de sulfato de bário, raros pigmentos de sulfato de bário no meio extracelular, importante proliferação fibroblástica em 13/14 (92% casos e não ocorreu formação de granulomas. No grupo-controle (22 ratos, o exame histopatológico foi normal em todas as fases do experimento. CONCLUSÕES: a o sulfato de bário causou derrame pleural inflamatório em todos os casos; b com 21 dias ocorreu formação de sínfises pleurais em 100% dos casos; c não houve formação de

  10. Influence of cavity design on the biomechanics of direct composite resin restorations in Class IV preparations.

    Science.gov (United States)

    Xu, Haiping; Jiang, Zhe; Xiao, Ximei; Fu, Jing; Su, Qin

    2012-04-01

    This study evaluated the effect of cavity design on stress distribution and fracture resistance of direct composite resin restorations in Class IV preparations. A finite element analysis (FEA) model of the maxillary central incisor with a Class IV cavity was established. Five model variations were studied: (i) a 1-mm bevel (ii) a 2-mm bevel, (iii) a plain chamfer, (iv) a stair-step chamfer, and (v) butt joints (a control configuration). All FEA variations modeled a tooth restored with composite resin loaded under 100 N at an angle of 45° to the longitudinal axis. The interfacial von Mises stress was evaluated. The FEA was complemented with an in vitro assessment. Fracture resistance of direct composite resin restorations was tested with a universal testing machine and fracture patterns were observed. Finite element analysis showed that stress in chamfer and stair-step chamfer models was more homogenously distributed, while stress in bevel models was relatively concentrated at lingual regions. Fracture resistance of a 1-mm bevel preparation was lower than for the 2-mm bevel, plain chamfer, and stair-step chamfer preparations, but was higher than for butt joints. The stair-step chamfer group presented the most favorable failure pattern. Considering biomechanics and esthetics, the present study indicates that the stair-step chamfer and 2-mm bevel should be recommended for clinical restoration. PMID:22409223

  11. Comparison of Dentin Permeability After Tooth Cavity Preparation with Diamond Bur and Er:YAG Laser

    OpenAIRE

    Hasani Tabatabaei, Masoumeh; Shirmohammadi, Sara; Yasini, Esmaeil; Mirzaei, Mansoureh; Arami, Sakineh; Kermanshah, Hamid; Ranjbar Omrani, Ladan; Alimi, Azar; Chiniforush, Nasim; Nakhostin, Afrooz; Abbasi, Mahdi

    2015-01-01

    Objectives: The aim of this study was to compare the permeability of dentin after using diamond bur and Er:YAG laser. Materials and Methods: Seventy-two recently extracted, intact, and restoration-free human permanent molars were used in this study. The samples were randomly divided into three groups of 24 each and class I cavities were prepared as follows. Group 1: High speed diamond bur with air and water spray. Group 2: Er:YAG laser. Group 3: Er:YAG laser followed by additional sub-ablativ...

  12. PAIN PERCEPTION OF PEDIATRIC PATIENTS DURING CAVITY PREPARATION WITH Er:YAG LASER AND CONVENTIONAL ROTARY INSTRUMENTS.

    OpenAIRE

    Ani Belcheva; Maria Shindova

    2014-01-01

    Aim: The aim of the present study is to evaluate and compare the pain perception of pediatric patients during cavity preparation with the use of Erbium:YAG laser 2940 nm and conventional rotary instruments. Methods and materials: A group of ninety 6-12-years-old patients with matched carious lesions (D3 threshold, WHO system) was divided into two equal treatment groups and treated without anaesthesia. In the intervention group the cavities were prepared with Erbium:YAG laser 2940nm and in ...

  13. The dimensional accuracy of preparation of femoral cavity in cementless total hip arthroplasty

    Institute of Scientific and Technical Information of China (English)

    吴立东; HAHNEH.J.; HASSENPFLUGJ.

    2004-01-01

    Objective: To observe the accuracy of femoral preparation and the position of the cementless prosthesis in femoral cavity, and to compare the results between the computer-assisted surgical group (CASPAR) and the conventional group. Methods: Ten femoral components were implanted either manually or by CASPAR in cadaver femurs. The specimens were cut to 3mm thick slices. Microradiograms of every slice were sent to a computer for analysis with special software (IDL). The gaps and the medullary cavities between component and bone, the direct bone contact area of the implant surface, the gap width and the percentage of gap and bone contact area were measured in every slice. Results: In the proximal implant coated with HA of the CASPAR group, the average percentage of bone contact reached 93.2% (ranging from 87.6% to 99.7%); the average gap percentage was 2.9% (ranging from 0.3% to 7.8%); the maximum gap width was 0.81mm and the average gap width was only 0.20mm. While in the conventional group, the average percentage of bone contact reached 60.1% (ranging from 49.2% to 70.4%); the average gap percentage was 32.8% (ranging from 25.1% to 39.9%); the maximum gap width was 2.97mm and the average gap width was 0.77mm. The average gap around the implant in the CASPAR group was only 9% of that in the manual group; the maximum and average gap widths were only about 26% of those in the manual group. On the other hand, the CASPAR group showed 33% higher bone contact than the manual group. Conclusion: With the use of robotics-assisted system, significant progress can be achieved for femoral preparation in total hip arthroplasty.

  14. The use of Erbium: Yttrium-aluminum-garnet laser in cavity preparation and surface treatment: 3-year follow-up.

    Science.gov (United States)

    Buyukhatipoglu, Isil; Secilmis, Asli

    2015-01-01

    From the currently available choices, esthetic restorative materials for posterior teeth are limited to composite and ceramic restoration. Ceramic inlays/onlays are reliable solutions for both of these treatments. For successful treatment planning, usable ceramic and adhesive systems should be chosen by the dentist. Since the Federal Drug Administration approval of the erbium: Yttrium-aluminum-garnet (Er:YAG) laser-for caries removal, cavity preparation and the conditioning of tooth substance-in 1997, there have been many reports on the use of this technique in combination with composite resins. In addition, cavity pretreatment with the Er:YAG laser (laser etching) has been proposed as an alternative to acid etching of enamel and dentin. This case report presents the use of the Er:YAG in cavity preparation for composite resin restoration and surface treatment for ceramic onlay restoration of adjacent permanent molars. PMID:26038665

  15. Biocompatibility of a restorative resin-modified glass ionomer cement applied in very deep cavities prepared in human teeth.

    Science.gov (United States)

    Soares, Diana Gabriela; Basso, Fernanda Gonçalves; Scheffel, Débora Lopes Sales; Giro, Elisa Maria Aparecida; de Souza Costa, Carlos Alberto; Hebling, Josimeri

    2016-01-01

    This study evaluated whether a restorative resin-modified glass ionomer cement, Vitremer (VM), would be biocompatible with pulp tissue when used as a liner in very deep cavities prepared in young human permanent teeth. Two dental cements in current use as liner materials, Vitrebond (VB) and Dycal (DY), were compared to VM. Class V cavities were prepared in 36 sound premolars that were scheduled for extraction, and the cavity floor was lined with the restorative cement (VM) or a liner/base control cement (VB or DY). For VM specimens, the cavity floor was pretreated with a primer (polyacrylic acid plus 2-hydroxyethyl methacrylate). Teeth were extracted after 7 or 30 days and processed for microscopic evaluation. In the VM group, inward diffusion of dental material components through dentinal tubules, associated with disruption of the odontoblastic layer, moderate to intense inflammatory response, and resorption of inner dentin, was observed in 2 teeth at 7 days. These histologic features were observed in 1 tooth at 30 days. In the VB group, mild inflammatory reactions and tissue disorganization observed at 7 days were resolved at 30 days. No pulpal damage occurred in the DY specimens. Of the materials tested, only Vitremer was not considered biocompatible, because it caused persistent pulpal damage when applied in very deep cavities (remaining dentin thickness less than 0.3 mm). PMID:27367631

  16. Efeitos do sulfato de bário na cavidade pleural de ratos Effects of barium sulphate in rats pleural cavity

    OpenAIRE

    Giovanni Antonio Marsico; Rui Haddad; Carlos Eduardo de Souza Carvalho; Patrícia Gioia de Assis; Ivam Martinelli Júnior; Maria Das Graças Martins

    2001-01-01

    OBJETIVO: Avaliar os efeitos do sulfato de bário na cavidade pleural de ratos. MÉTODO: Foram avaliados, experimentalmente, os efeitos do sulfato de bário a 100% na cavidade pleural de 43 ratos. Sob anestesia inalatória com éter, foi realizada injeção de contraste radiológico (1ml) na cavidade pleural direita após punção com agulha romba pela via subxifóide. Os ratos, divididos em três grupos, foram mortos em câmara fechada com éter, após 24h (13 ratos), 48h (16 ratos) e 21 dias (14 ratos), re...

  17. Scanning electron microscopy evaluation of the interaction pattern between dentin and resin after cavity preparation using Er:YAG laser

    International Nuclear Information System (INIS)

    The aim of this study was to describe the interaction pattern formed between dentin and resin on cavities prepared with an erbium laser (Er:YAG). The morphological aspect of the irradiated dentin after acid etching was also observed. Ten dentin disks were obtained from fresh extracted third molars. Each disk received two cavities, one prepared with a conventional high-speed drill, while the other cavity was obtained by the use of an Er:YAG laser (KaVo KEY Laser, KaVo Co.). The laser treatment was performed with 250 mJ/pulse, 4 Hz, non contact mode, focused beam, and a fine water mist was used. Five disks were prepared for morphological analysis of the acid etched dentin. The other five disks had their cavities restored with Single Bond (3M) followed by Z100 resin (3M). The specimens were observed under scanning electron microscopy after dentin-resin interface demineralization and deproteinization. It was observed that the morphological characteristics of the acid-etched irradiated dentin were not favorable to the diffusion of monomers through the collagen network. The dentin resin interfacial aspect of irradiated dentin, after acid etching, showed thin tags and scarce hybridization zones, which agreed with the morphology of the irradiated and acid-etched dentin substrate observed. (author)

  18. Evidence-based concepts and procedures for bonded inlays and onlays. Part II. Guidelines for cavity preparation and restoration fabrication.

    Science.gov (United States)

    Rocca, Giovanni Tommaso; Rizcalla, Nicolas; Krejci, Ivo; Dietschi, Didier

    2015-01-01

    The second part of this article series presents an evidence-based update of clinical protocols and procedures for cavity preparation and restoration selection for bonded inlays and onlays. More than ever, tissue conservation dictates preparation concepts, even though some minimal dimensions still have to be considered for all restorative materials. In cases of severe bruxism or tooth fragilization, CAD/CAM composite resins or pressed CAD/CAM lithium disilicate glass ceramics are often recommended, although this choice relies mainly on scarce in vitro research as there is still a lack of medium- to long-term clinical evidence. The decision about whether or not to cover a cusp can only be made after a multifactorial analysis, which includes cavity dimensions and the resulting tooth biomechanical status, as well as occlusal and esthetic factors. The clinical impact of the modern treatment concepts that were outlined in the previous article - Dual Bonding (DB)/Immediate Dentin Sealing (IDS), Cavity Design Optimization (CDO), and Cervical Margins Relocation (CMR) - are described in detail in this article and discussed in light of existing clinical and scientific evidence for simpler, more predictable, and more durable results. Despite the wide choice of restorative materials (composite resin or ceramic) and techniques (classical or CAD/CAM), the cavity for an indirect restoration should meet five objective criteria before the impression. PMID:26171443

  19. Frequency of Iatrogenic damage to adjacent tooth during class II cavity preparation among dental students at Tehran University of Medical Sciences in 2010

    OpenAIRE

    Reza Yazdani; Hamide Kalkou; Mohammadreza Khami

    2013-01-01

      Background and Aims: Iatrogenic damage to adjacent tooth during proximal cavity preparation is one of the most common side effects in operative dentistry. The aim of this study was to determine prevalence of iatrogenic damages to adjacent tooth during the preparation of proximal Class II cavities among undergraduate students at dental faculty of Tehran University of Medical Sciences in 2010 .   Materials and Methods: 106 posterior permanent teeth which had Class II decay with sound proximal...

  20. Cluster-state preparation in thermal cavities without single-qubit operation

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiao-Long; Feng Mang; Gao Ke-Lin

    2008-01-01

    A potential scheme is proposed for generating cluster states of many atoms in cavity quantum electradynamics We show how to create the cluster states by performing a two-step but no single-qubit operation.Discussion is also carried out on the experimental feasibility of our scheme.

  1. PAIN PERCEPTION OF PEDIATRIC PATIENTS DURING CAVITY PREPARATION WITH Er:YAG LASER AND CONVENTIONAL ROTARY INSTRUMENTS.

    Directory of Open Access Journals (Sweden)

    Ani Belcheva

    2014-11-01

    Full Text Available Aim: The aim of the present study is to evaluate and compare the pain perception of pediatric patients during cavity preparation with the use of Erbium:YAG laser 2940 nm and conventional rotary instruments. Methods and materials: A group of ninety 6-12-years-old patients with matched carious lesions (D3 threshold, WHO system was divided into two equal treatment groups and treated without anaesthesia. In the intervention group the cavities were prepared with Erbium:YAG laser 2940nm and in the control group with conventional rotary instruments. At the end of the treatment each patient was asked to point the degree of its pain on the universal pain assessment tool. Results: Participants in the laser treatment group reported significantly lower pain scores compared to participants in the control group (p<0.005. The analysis of pain indicated that in the intervention group the scores obtained from the majority of cases (71.1% were low and only one patient reported severe pain perception. In the conventional treatment group the results showed approximately equal frequency for low (40% and moderate (42.2% pain level. Conclusions: The Erbium:YAG lasers produce less pain compared to the conventional mechanical preparation. They offer new and useful possibilities in restorative dentistry in pediatric dentistry and are good treatment options.

  2. SUBJECTIVE ACCEPTANCE OF PEDIATRIC PATIENTS DURING CAVITY PREPARATION WITH Er:YAG LASER AND CONVENTIONAL ROTARY INSTRUMENTS.

    OpenAIRE

    Ani Belcheva; Maria Shindova

    2014-01-01

    Aim: The aim of the present study is to evaluate and compare the subjective acceptance in children during hard dental tissue therapy using Er:YAG laser 2940nm and conventional rotary instruments. Methods and materials: The study included ninety 6-12-years-old children with matched carious lesions (D3 threshold, WHO system), divided into two equal treatment groups. In the intervention group the cavities were prepared with Erbium:YAG laser 2940nm and in the control group with conventional r...

  3. Effects of low-intensity GaAlAs laser radiation (λ=660 nm) on dentine-pulp interface after class I cavity preparation

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the effects of low-intensity irradiation with GaAlAs laser (red emission) on the ultrastructure of dentine-pulp interface after conventionally prepared class I cavity preparation. Two patients with 8 premolars for extraction indicated for orthodontic reasons. Class I cavities were prepared in these teeth that were then divided into two groups. The first group received a treatment with laser with continuous emission, λ=660 nm, with maximum power output of 30 mW. The dosimetry applied was of approximately 2J/cm2, directly and perpendicularly into the cavity in only one section. After the irradiation, the cavities were filled with composite resin. The second group received the same treatment, except by the laser therapy. Twenty-eight days after the preparation, the teeth were extracted and were processed for transmission electron microscopy analysis. Two sound teeth, without any preparation, were also studied. The irradiated group presented odontoblastic processes in higher contact with the extracellular matrix and the collagen fibers appeared more aggregated and organized than those of control group. These results were also observed in the healthy-teeth. Thus, we suggest that laser irradiation accelerates the recovery of the dental structures involved in the cavity preparation at the pre-dentine level. (author)

  4. Evolução dos preparos das cavidades de classe II Developments in preparation of class II cavities

    Directory of Open Access Journals (Sweden)

    Mary Miyuki ONO

    1997-01-01

    Full Text Available A evolução dos preparos de classe II com a introdução de novos materiais e a conscientização da importância da preservação de estrutura dental sadia são abordadas nos preparos do tipo Almqvist, Roggenkamp e túnel, em que se observa a necessidade de menor desgaste da estrutura dentária, com aumento da resistência à fratura, melhor estética e melhor retençãoDevelopments in preparation of class II cavities with the introduction of new materials and awareness of the importance of preservation of a sound dental structure are broached in preparations of the type Almqvist, Roggenkamp and tunnel, where the need for less wear of the dental structure was observed with an increase in fracture strength, better aesthetics, and better retention

  5. Femtosecond laser for cavity preparation in enamel and dentin: ablation efficiency related factors

    OpenAIRE

    Chen, H.; Li, H.; YC. Sun; Wang, Y.; PJ. Lü

    2016-01-01

    To study the effects of laser fluence (laser energy density), scanning line spacing and ablation depth on the efficiency of a femtosecond laser for three-dimensional ablation of enamel and dentin. A diode-pumped, thin-disk femtosecond laser (wavelength 1025 nm, pulse width 400 fs) was used for the ablation of enamel and dentin. The laser spot was guided in a series of overlapping parallel lines on enamel and dentin surfaces to form a three-dimensional cavity. The depth and volume of the ablat...

  6. Femtosecond laser for cavity preparation in enamel and dentin: ablation efficiency related factors

    Science.gov (United States)

    Chen, H.; Li, H.; Sun, Yc.; Wang, Y.; Lü, Pj.

    2016-02-01

    To study the effects of laser fluence (laser energy density), scanning line spacing and ablation depth on the efficiency of a femtosecond laser for three-dimensional ablation of enamel and dentin. A diode-pumped, thin-disk femtosecond laser (wavelength 1025 nm, pulse width 400 fs) was used for the ablation of enamel and dentin. The laser spot was guided in a series of overlapping parallel lines on enamel and dentin surfaces to form a three-dimensional cavity. The depth and volume of the ablated cavity was then measured under a 3D measurement microscope to determine the ablation efficiency. Different values of fluence, scanning line spacing and ablation depth were used to assess the effects of each variable on ablation efficiency. Ablation efficiencies for enamel and dentin were maximized at different laser fluences and number of scanning lines and decreased with increases in laser fluence or with increases in scanning line spacing beyond spot diameter or with increases in ablation depth. Laser fluence, scanning line spacing and ablation depth all significantly affected femtosecond laser ablation efficiency. Use of a reasonable control for each of these parameters will improve future clinical application.

  7. SUBJECTIVE ACCEPTANCE OF PEDIATRIC PATIENTS DURING CAVITY PREPARATION WITH Er:YAG LASER AND CONVENTIONAL ROTARY INSTRUMENTS.

    Directory of Open Access Journals (Sweden)

    Ani Belcheva

    2014-11-01

    Full Text Available Aim: The aim of the present study is to evaluate and compare the subjective acceptance in children during hard dental tissue therapy using Er:YAG laser 2940nm and conventional rotary instruments. Methods and materials: The study included ninety 6-12-years-old children with matched carious lesions (D3 threshold, WHO system, divided into two equal treatment groups. In the intervention group the cavities were prepared with Erbium:YAG laser 2940nm and in the control group with conventional rotary instruments, without anaesthesia. After cavity preparation patient’s subjective acceptance was assessed by a questionnaire concerning primary stress triggers. Results: The annoyance factor (vibration was found as a stress trigger in the majority of control children (86.7%, while in the intervention group it was found in 2.2% of cases. The most anxiety provoking items in the intervention group were smell (67.7% and taste (42.2%. The sound was found to be a stress trigger in more than half of control children (62.2% and less than one-fifth of the children in the intervention group (15.6%. The study results showed significant difference in these items between two groups (p< 0.001. Conclusions: The Erbium:YAG lasers reduce three of four stress triggers in `4S` principle - vibration, sight and sound. They are a good treatment option for fearful children since they have acceptable efficiency in treatment of pediatric anxiety disorders compared to the mechanical preparation.

  8. Morphological analysis of cavities prepared by different parameters of Er:YAG laser

    Science.gov (United States)

    Freitas, Patricia M.; Navarro, Ricardo S.; Almeida, Juliana; Imparato, Jose Carlos P.; Eduardo, Carlos P.

    2005-03-01

    The purpose of this study was to evaluate the morphological changes in cavities made by Er:YAG laser (2.94μm)(KaVo KEY 3)(LELO-FOUSP) and high-speed drill. Cavities were made on the buccal and lingual surfaces of 27 human molars (Banco de Dentes-FOUSP), using different laser parameters (n=3): G1-15Hz/160mJ enamel/ 6Hz/200mJ dentin; G2-15Hz/180mJ enamel/ 6Hz/200mJ dentin; G3-15Hz/160mJ enamel/ 6Hz/250mJ dentin; G4-15Hz/180mJ enamel/ 6Hz/250mJ dentin; G5-15Hz/180mJ enamel/ 10Hz/180mJ dentin; G6-15Hz/160mJ enamel/ 10Hz/180mJ dentin; G7-15Hz/160mJ enamel/ 10Hz/160mJ dentin; G8-15Hz/180mJ enamel/ 10Hz/160mJ dentin and G9-high-speed drill. Samples were fixed (2.5% glutaraldhyde, 12h, 4°C), dehydrated (25-100% ethanol), dried to a critical point and sputter-coated with gold for analysis under SEM. All laser parameters used showed no evidence of thermal damage and signs of burning and melting, Er:YAG laser ablated dental hard tissues, showing enamel prisms, like scales, dentin surface without smear layer and opened dentinal tubules. It was concluded that Er:YAG laser parameters were effective for ablation of hard tissues, promoting morphological changes in irradiated tissues, creating an irregular and microretentive morphological pattern.

  9. Comparison of Micro-Leakage from Resin-Modified Glass Ionomer Restorations in Cavities Prepared by Er:YAG (Erbium-Doped Yttrium Aluminum Garnet) Laser and Conventional Method in Primary Teeth

    OpenAIRE

    Bahrololoomi, Zahra; Razavi, Forooghosadat; Soleymani, Ali Asghar

    2014-01-01

    Introduction: In recent years, significant developments have been taking place in caries removal and cavity preparation using laser in dentistry. As laser use is considered for cavity preparation, it is necessary to determine the quality of restoration margins. Glass ionomer cements have great applications for conservative restoration in the pediatric field. The purpose of this in vitro study was to compare resin-modified glass ionomer restorations micro-leakage in cavities prepared by Er:YAG...

  10. Morphological evaluation of cavity preparation surface after duraphat and Er:YAG laser treatment by scanning electronic microscopy

    International Nuclear Information System (INIS)

    The treatment of dental surface using different lasers to prevent dental caries has been studied for several on last years. The purpose of this in vitro study was to evaluate the morphological changes on dentin surface from pulpal wall of cavity preparations performed by high-speed drill, treated with 2,26% fluoride varnish (Duraphat) and Er:YAG laser, and then submitted after receiving or not to EDTA 15% treatment. Twenty Class V cavities were performed on ten humans molars. The specimens were randomly divided in to 4 groups: group 1- treatment with Duraphat followed by Er:YAG laser irradiation (120 mJ/ 4 Hz); group 2: Er:YAG laser irradiation, same parameters, followed by Duraphat treatment; group 3- same group 1 followed by immersion in EDTA (5 min); group 4 - same as group 2 followed by immersion in EDTA (5 min). The specimens were processed for SEM analysis. The micrographs showed that Duraphat treatment promoted morphological changes on dentin, closing dentinal tubules; the specimens treated by Duraphat and Er:YAG laser and immersed in EDTA (group 3) showed homogeneous surface, closed and protected dentinal tubules, maintenance of the fluoride varnish on the dentin surface and around the dentinal tubules, showing feasible and efficiency of these therapies the feasibility.(author)

  11. Preparation of n-qubit Greenberger-Horne-Zeilinger entangled states in cavity QED: An approach with tolerance to nonidentical qubit-cavity coupling constants

    International Nuclear Information System (INIS)

    We propose a way for generating n-qubit Greenberger-Horne-Zeilinger (GHZ) entangled states with a three-level qubit system and (n-1) four-level qubit systems in a cavity. This proposal does not require identical qubit-cavity coupling constants and thus is tolerant to qubit-system parameter nonuniformity and nonexact placement of qubits in a cavity. The proposal does not require adjustment of the qubit-system level spacings during the entire operation. Moreover, it is shown that entanglement can be deterministically generated using this method and the operation time is independent of the number of qubits. The present proposal is quite general, which can be applied to physical systems such as various types of superconducting devices coupled to a resonator or atoms trapped in a cavity.

  12. Marginal microleakage in vitro study on class V cavities prepared with Er:YAG laser and etched with acid or etched with Er:YAG laser and acid

    International Nuclear Information System (INIS)

    Microleakage at the interface between the teeth and the restorative materials remains a problem with composite resin restorations. Microleakage at the gingival margins of class V cavities restorations still challenge as they are usually placed in dentin and/or cementum. Previous studies have shown that the cavity preparation with Er:YAG laser is possible. It has been reported that Er:YAG laser has ability to create irregular surface providing micromechanical retention for adhesive dental restorative materials and to improve marginal sealing. The purpose of this in vitro study was to evaluate the marginal microleakage on class V cavities prepared with Er:YAG laser and etched with acid or with Er:YAG laser and acid, in compared to those prepared and etched conventionally. Thirty human molars were divided into three groups, namely: group I - prepared with Er:YAG laser (KaVo KEY Laser II - Germany) and etched with 37% phosphoric acid; group II - prepared with Er:YAG laser and etched with Er:YAG laser and 37% phosphoric acid; group III (control group) - prepared with high speed drill and etched with 37% phosphoric acid. All cavities were treated with same adhesive system (Single Bond - 3M) and restored with the composite resin (Z100 - 3M), according to the manufacturer's instructions. The specimens were stored at 37 deg C in water for 24 hours, polished with Sof-Lex discs (3M), thermally stressed, sealed with a nail polish coating except for the area of the restoration and 1 mm around it, and immersed in a 50% aqueous solution of silver nitrate for 24 hours. After that, the specimens were rinsed in water, soaked in a photodeveloping solution and exposed to a fluorescent light for 8 hours. The teeth were embedded in an autopolymerizing resin and sectioned longitudinally using a diamond saw microtome under running water. The sections were photographed. The microleakage at the occlusal cavity and at the gingival margins of each specimen was evaluated with scores (0-3) by

  13. The effect of insertion and photopolymerization techniques on microleakage of Class V cavities: a quantitative evaluation Efeito de diferentes técnicas de inserção e fotopolimerização na microinfiltração de cavidades Classe V: avaliação quantitativa

    OpenAIRE

    Fabiana Mantovani Gomes França; Frederico Seidi Hori; Alex José Souza dos Santos; José Roberto Lovadino

    2005-01-01

    The aim of this in vitro study was to evaluate by spectrophotometry the influence of the incremental technique and progressive light curing in the microleakage of Class V cavities. Forty samples were prepared with class V cylindrical cavities on the buccal root surface of bovine incisive teeth and filled with composite resin (Z250). The samples were divided into four groups: I: cavity was bulk filled and the composite was light cured for 40 seconds; Group II: cavity was bulk filled and a "sof...

  14. Photonic crystal cavity embedded barium strontium titanate thin-film rib waveguide prepared by focused ion beam etching

    International Nuclear Information System (INIS)

    A photonic crystal (PC) cavity embedded Ba0.7Sr0.3TiO3 (barium strontium titanate, or BST) rib waveguide, which functions as an optical filter at λ = 1550 nm, is designed using finite-difference time-domain (FDTD) simulation. The PC cavity is composed of two 5-row photonic crystal mirrors, which are formed by air holes (radii 250 nm) arranged in triangular lattice (periodicity 625 nm) in the BST matrix. Calculations suggested that the required cavity length should be 800 nm for the resonant peak to be situated at 1550 nm. Based on this design, PC cavities were fabricated on BST thin-film rib waveguides by focused ion beam etching with satisfactory results. The transmission spectra of the BST thin-film rib waveguides with PC cavities have been measured. The results agreed well with the FDTD simulation.

  15. Preparation of Entanglement and Schrodinger Cat States of Superconducting Quantum Interference Devices Qubits via Coupling to a Microwave Cavity

    Institute of Scientific and Technical Information of China (English)

    LI Sheng-Chang; YANG Wen-Xing; DUAN Wen-Shan

    2008-01-01

    An alternative scheme is proposed for the generation of n-qubit W states of superconducting quantum interference devices (SQUID) in cavity QED. In this scheme, Raman coupling of two lower flux states of SQUID system is achieved via a microwave pulse and the cavity mode. Conditioned on no photon leakage from the cavity, the n-qubit W state can be generated whether the effective coupling parameters of the SQUID to cavity mode and classical microwave fields are the same or different. Our strictly numerical simulations of the time evolution of the system including decay show that the success probability of our scheme is almost unity and the interaction time is on the order of 10-9 s. The scheme can also be used to generate the Schrfdinger cat states of multi-SQUID.

  16. Effect of irradiation mode and filling technique on resin/dentin bonding strength in class I cavities Efeito do modo de ativação e da técnica restauradora na resistência de união entre compósito e dentina em cavidades classe I

    Directory of Open Access Journals (Sweden)

    Alex José Souza dos Santos

    2004-09-01

    Full Text Available Factors such as light-curing mode, filling technique and cavity configuration may affect the bonding strength to dentin. This study evaluated the effect of irradiation mode and filling technique on resin/dentin bonding strength on the buccal wall of class I cavities in human teeth. Occlusal enamel was removed to expose a flat dentin surface. Occlusal cavities (4 x 3 x 3 mm were prepared in dentin. The adhesive Single Bond was applied according to the manufacturer's instructions and TPH Spectrum composite resin was placed using the following: oblique incremental, horizontal incremental or bulk filling techniques. The composite resin was light-cured either by continuous (600 mW/cm² for 40 s or Soft-Start (250 mW/cm² for 10 s + 600 mW/cm² for 30 s modes. Specimens of the control group were obtained by bonding the material to the flat exposed buccal wall of the cavity (C-factor = 1. The teeth were stored in water at 37ºC for 24 h and prepared for microtensile testing. Bonded beams of approximately 0.8 mm² were obtained from the buccal wall and tested with a tension of 0.5 mm/min. Results were analyzed by two-way ANOVA, Tukey's test and Dunnett's test (alpha = 0.05. Incremental placement techniques with both irradiation modes produced higher bonding strength values than the bulk technique (p Fatores como o modo de ativação, a técnica restauradora e a configuração cavitária podem afetar a resistência adesiva à dentina. Este estudo avaliou os efeitos dos modos de ativação e das técnicas restauradoras na resistência de união compósito/dentina na parede vestibular de restaurações classe I. O esmalte oclusal dos dentes foi removido para expor uma superfície dentinária planificada. Cavidades oclusais (4 x 3 x 3 mm foram preparadas em dentina. O adesivo Single Bond foi aplicado de acordo com as instruções do fabricante, e o compósito TPH Spectrum, inserido através de três diferentes técnicas: oblíqua incremental, horizontal

  17. Influence of different composite materials and cavity preparation designs on the fracture resistance of mesio-occluso-distal inlay restoration.

    Science.gov (United States)

    Tekçe, Neslihan; Pala, Kansad; Demirci, Mustafa; Tuncer, Safa

    2016-01-01

    The aim of the study to evaluate the fracture resistance of a computer-aided design/computer-aided manufacturing (CAD/CAM) and three indirect composite materials for three different mesio-occluso-distal (MOD) inlay cavity designs. A total of 120 mandibular third molar were divided into three groups: (G1) non-proximal box, (G2) 2-mm proximal box, and (G3) 4-mm proximal box. Each cavity design received four composite materials: Estenia, Epricord (Kuraray, Japan), Tescera (Bisco, USA), and Cerasmart CAD/CAM blocks (GC, USA). The specimens were subjected to a compressive load at a crosshead speed of 1 mm/min. The data was analyzed using the two-way analysis of variance and Bonferroni post hoc test (prestoration. PMID:27252011

  18. Superconducting cavity development

    International Nuclear Information System (INIS)

    Design and development work of the superconducting cavities for the Neutron Science Project is being continued since 1995. In the cavity design work, RF and structural analyses were carried out in order to determine the cavity shape and to obtain the RF and structural parameters. In the cavity development work, preparation of the test facility, fabrication and tests of the two single-cell prototype cavities of β=0.5 were performed. Good performance of the cavity was demonstrated in the test; obtained surface peak electric field of 44 MV/m is much higher than the design value of 16 MV/m. Resonant frequency shifts due to the vacuum load and the Lorentz force were also measured in the test. (author)

  19. Frequency Tuning for a DQW Crab Cavity

    CERN Document Server

    Verdú-Andrés, Silvia; Ben-Zvi, Ilan; Calaga, Rama; Capatina, Ofelia; Leuxe, Raphael; Skaritka, John; Wu, Qiong; Xiao, Binping; Zanoni, Carlo

    2016-01-01

    The nominal operating frequency for the HL-LHC crab cavities is 400.79 MHz within a bandwidth of ±60kHz. Attaining the required cavity tune implies a good understanding of all the processes that influence the cavity frequency from the moment when the cavity parts are being fabricated until the cavity is installed and under operation. Different tuning options will be available for the DQW crab cavity of LHC. This paper details the different steps in the cavity fabrication and preparation that may introduce a shift in the cavity frequency and introduces the different tuning methods foreseen to bring the cavity frequency to meet the specifications.

  20. Changeability of Oral Cavity Environment

    OpenAIRE

    Surdacka, Anna; Strzyka³a, Krystyna; Rydzewska, Anna

    2007-01-01

    Objectives In dentistry, the results of in vivo studies on drugs, dental fillings or prostheses are routinely evaluated based on selected oral cavity environment parameters at specific time points. Such evaluation may be confounded by ongoing changes in the oral cavity environment induced by diet, drug use, stress and other factors. The study aimed to confirm oral cavity environment changeability. Methods 24 healthy individuals aged 20–30 had their oral cavity environment prepared by having p...

  1. Shortcuts to adiabatic passage for multiparticles in distant cavities: applications to fast and noise-resistant quantum population transfer, entangled states’ preparation and transition

    International Nuclear Information System (INIS)

    In this letter, we study the fast and noise-resistant population transfer, quantum entangled states’ preparation and quantum entangled states’ transition by constructing shortcuts to adiabatic passage (STAP) for multiparticles based on the approach of ‘Lewis–Riesenfeld invariants’ in a distant cavity quantum electronic dynamics (QED) system. Numerical simulation demonstrates that all of the schemes are fast and robust against the decoherence caused by atomic spontaneous emission and photon leakage. Moreover, it is not only the total operation time but also the robustness in each scheme against decoherence that is irrelevant to the number of qubits. This might lead to a useful step toward realizing fast and noise-resistant quantum information processing in current technology. (letter)

  2. Seamless/bonded niobium cavities

    Science.gov (United States)

    Singer, W.

    2006-07-01

    Technological aspects and performance of seamless cavities produced by hydroforming are presented. Problems related to the fabrication of seamless cavities from bulk niobium are mainly solved thanks to the progress of the last years. The highest achieved accelerating gradients are comparable for both seamless and welded versions (ca. 40 MV/m) Nevertheless further development of seamless cavities is desirable in order to avoid the careful preparation of parts for welding and get reliable statistic. Fabrication of NbCu clad cavities from bimetallic tubes is an interesting option that gives new opportunity to the seamless technique. On the one hand it allows reducing the niobium costs contribution; on the other hand it increases the thermal stability of the cavity. The highest accelerating gradient achieved on seamless NbCu clad single cell cavities (ca. 40 MV/m) is comparable to the one reached on bulk Nb cavities. Fabrication of multi-cell NbCu cavities by hydroforming was recently proven.

  3. Superconducting cavities

    International Nuclear Information System (INIS)

    The basic properties of superconducting cavities for electron accelerators are discussed with special emphasis on the following topics: technical motivation for the use of superconducting cavities; surface impedance; the critical field of superconductors; anomalous losses; materials other than niobium; technological achievements for accelerating cavities. (author)

  4. Guided access cavity preparation using cone-beam computed tomography and optical surface scans - an ex vivo study

    DEFF Research Database (Denmark)

    Buchgreitz, J; Buchgreitz, M; Mortensen, D;

    2016-01-01

    AIM: To evaluate ex vivo, the accuracy of a preparation procedure planned for teeth with pulp canal obliteration (PCO) using a guide rail concept based on a cone-beam computed tomography (CBCT) scan merged with an optical surface scan. METHODOLOGY: A total of 48 teeth were mounted in acrylic blocks....... An apical canal preparation was created to simulate remnants of an apical root canal that acted as the target for a drill path. The test blocks were surface scanned, and merged with a CBCT scan, and a guide rail was made. A pathway for the bur was created through a metal sleeve within the guide rail...... into dentine. The distance was measured between the centres of the performed drill path and the apical target by two examiners. A maximum distance of 0.7 mm was defined based on the radius of the bur (0.6 mm) and the radius of a root canal just visible on a radiograph (0.1 mm). The t-test was used for...

  5. Influence of the power level of an ultra-sonic system on dental cavity preparation Influência do nível de potência de um sistema de ultra-som em preparos cavitários

    OpenAIRE

    Érika Botelho Josgrilberg; Murilo de Sousa Guimarães; Cyneu Aguiar Pansani; Rita de Cássia Loiola Cordeiro

    2007-01-01

    The aim of this study was to evaluate the shape of dental cavities made with the CVDentus® system using different ultrasound power levels. One standard cavity was made on the buccal aspect of 15 bovine incisors with a CVDentus® cylindrical bur (82142). The sample was divided into three groups: G1 - ultrasound with power II; G2 - ultrasound with power III; and G3 - ultrasound with power IV. A standardizing device was used to obtain standardized preparations and ultrasound was applied during on...

  6. Superconducting cavity model for LEP

    CERN Multimedia

    1979-01-01

    A superconducting cavity model is being prepared for testing in a vertical cryostat.At the top of the assembly jig is H.Preis while A.Scharding adjusts some diagnostic equipment to the cavity. See also photo 7912501X.

  7. Dental cavities

    Science.gov (United States)

    ... leading to cavities. Treatment may involve: Fillings Crowns Root canals Dentists fill teeth by removing the decayed tooth ... gold, porcelain, or porcelain attached to metal. A root canal is recommended if the nerve in a tooth ...

  8. radiofrequency cavity

    CERN Multimedia

    1988-01-01

    The pulse of a particle accelerator. 128 of these radio frequency cavities were positioned around CERN's 27-kilometre LEP ring to accelerate electrons and positrons. The acceleration was produced by microwave electric oscillations at 352 MHz. The electrons and positrons were grouped into bunches, like beads on a string, and the copper sphere at the top stored the microwave energy between the passage of individual bunches. This made for valuable energy savings as it reduced the heat generated in the cavity.

  9. The effect of insertion and photopolymerization techniques on microleakage of Class V cavities: a quantitative evaluation Efeito de diferentes técnicas de inserção e fotopolimerização na microinfiltração de cavidades Classe V: avaliação quantitativa

    Directory of Open Access Journals (Sweden)

    Fabiana Mantovani Gomes França

    2005-03-01

    Full Text Available The aim of this in vitro study was to evaluate by spectrophotometry the influence of the incremental technique and progressive light curing in the microleakage of Class V cavities. Forty samples were prepared with class V cylindrical cavities on the buccal root surface of bovine incisive teeth and filled with composite resin (Z250. The samples were divided into four groups: I: cavity was bulk filled and the composite was light cured for 40 seconds; Group II: cavity was bulk filled and a "soft-start" polymerization was used; Group III: cavity was filled with the incremental technique in two coats and light cured for 40 seconds; Group IV: cavity was filled with the incremental technique in two coats and light cured with "soft-start" polymerization. After the restoration, the specimens were thermally stressed for 3,000 cycles in bath at 5 ± 2°C and 55 ± 2°C, protected with nail enamel, colored with 2% methylene blue and cut into sections. These sections were triturated and the dye was recovered with PA ethanol and the supernatant was evaluated. The data were submitted to ANOVA and the results showed the following averages: bulk filled and conventional photopolymerization (I 0.06075 µg/ml; bulk filled and progressive photopolymerization (II 0.04030 µg/ml; incremental insertion and conventional photopolymerization (III 0.04648 µg/ml; incremental insertion and progressive photopolymerization (IV 0.04339 µg/ml. No significant statistic differences were observed among the mean values. The Degulux "soft-start" equipment probably emits too high initial light intensity to promote progressive photopolymerization.O objetivo deste estudo in vitro foi avaliar através de espectrofotometria a influência das técnicas de inserção incremental e de fotopolimerização progressiva na microinfiltração de cavidades Classe V. Foram preparadas 40 cavidades cilíndricas na superfície radicular vestibular de incisivos bovinos e preenchidas com resina

  10. accelerating cavity

    CERN Multimedia

    On the inside of the cavitytThere is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  11. O efeito facilitatório do óxido nítrico sobre a transmissão neuromuscular de preparações nervo frênico- diafragma isolado de ratos é Ca++ dependente - DOI: 10.4025/actascibiolsci.v26i4.1528 NO- induced neuromuscular facilitation in the phrenic nerve diaphragm preparation of rats is Ca++ dependent - DOI: 10.4025/actascibiolsci.v26i4.1528

    Directory of Open Access Journals (Sweden)

    Heraldo Esheveria Borges

    2004-04-01

    Full Text Available A pesquisa foi conduzida para verificar se os efeitos neuromusculares induzidos por óxido nítrico (NO poderiam depender dos níveis extracelulares de Ca++. O doador de NO, nitroprussiato de sódio (NPS, e o análogo de GMPc, 8-Br-cGMP, aumentaram a amplitude das contrações musculares (ACM em preparações indiretamente estimuladas a 0.2 Hz, mas não produziram efeitos quando a solução nutriente (Krebs normal foi trocada por Krebs com baixo Ca++/ alto Mg++. NPS e 8-Br-cGMP reduziram a ACM quando as preparações foram diretamente estimuladas, mas tal efeito não foi observado com o uso de Krebs com baixo Ca++/ alto Mg++. Dados sugerem que os efeitos neuromusculares induzidos por NO dependem dos níveis extracelulares de Ca++The research was carried out to verify whether the neuromuscular effects induced by nitric oxide (NO might depend on extracellular level of Ca++. The donor of NO, sodium nitroprusside (SNP, and the analogue of cGMP, 8-Br-cGMP, increased the muscular contraction amplitude (MCA in preparations indirectly stimulated at 0.2 Hz, but did not produce any effect when the nutrient solution was exchanged by Krebs buffer low Ca++/ high Mg++. SNP and 8-Br-cGMP reduced the MCA in preparations directly stimulated. Such effect was not recorded in Krebs buffer low Ca++/ high Mg++. Data suggest that the neuromuscular effects induced by NO or cGMP depend on extracellular level of Ca++

  12. Teleportation of Atomic States via Cavity Quantum Electrodynamics

    CERN Document Server

    Guerra, E S

    2004-01-01

    In this article we discuss a scheme of teleportation of atomic states. The experimental realization proposed makes use of cavity Quatum Electrodynamics involving the interaction of Rydberg atoms with a micromaser cavity prepared in a coherent state. We start presenting a scheme to prepare atomic Bell states via the interaction of atoms with a cavity. In our scheme the cavity and some atoms play the role of auxiliary systems used to achieve the teleportation.

  13. CHECHIA cavity driving with FPGA controller

    International Nuclear Information System (INIS)

    The initial control of the superconductive cavity has recently been performed by applying the FPGA (Field Programmable Gate Array) technology system in DESY Hamburg. This first experiment turned attention to the general recognition of the cavity features and projected control methods. The electrical model of the cavity is taken as a consideration origin. The calibration of the signal channel is considered as a key preparation for an efficient cavity driving. The cavity parameters identification is confirmed as a proper approach for the required performance: driving on resonance during filling and field stabilization during flattop time with reasonable power consumption. The feed-forward and feedback modes were applied successfully for the CHECHIA cavity driving. Representative results of experiments are presented for different levels of the cavity field gradient. (orig.)

  14. Cavity magnomechanics

    Science.gov (United States)

    Zou, Chang-Ling; Zhang, Xufeng; Jiang, Liang; Tang, Hong

    2016-05-01

    Recently, cavity magnonics has attracted much attention for potential applications of coherent information transduction and hybrid quantum devices. The magnon is a collective spin wave excitation in ferromagnetic material. It is magnetically tunability, with long coherence time and non-reciprocical interaction with electro-magnetic fields. We report the coherent coupling between magnon, microwave photon and phonon. First, we demonstrate strong coupling and ultrastrong coupling between the magnon in YIG sphere and microwave photon in three-dimensional cavity. Then, based on the hybridized magnon-photon modes, we observe the triply resonant magnon-mcirowave photon-phonon coupling, where the ultrahigh-Q mechanical vibration of YIG sphere is dispersively coupled with the magnon via magnetostrictive interaction. We observe interesting phenomena, including electromagnetically induced transparency/absorption and parametric amplification. In particular, benefit from the large tunability of the magnon, we demonstrate a tunable microwave amplifier with gain as high as 30 dB. The single crystal YIG also has excellent optical properties, and thus provide a unique platform bridging MHz, GHz and THz information carriers. Finally, we present the latest progress towards coherent magnon to optical photon conversion.

  15. Agent for roentgenocontrast examination of cavities

    International Nuclear Information System (INIS)

    The water-soluble agent, additionaly containing starch, agar, water, is suggested to increase accuracy of injured cavity diagnostics. The method for roentgenocontrast agent preparation on the base of starch-agar gel is described. Advantages of the agent suggested in comparison with those of roentgenologic cavity investigation used are shown

  16. Generation of Cluster States in Cavity QED

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yan-Li; YANG Li-Jia; DAI Hong-Yi

    2007-01-01

    We propose two schemes for the generation of cluster states in the context of cavity quantum electrodynamics (QED).In the first scheme,we prepare multi-cavity cluster states with information encoded in the coherent states.The second scheme is to generate multi-atom cluster states,where qubits are represented by the states of cascade Rydberg atoms.Both the schemes are based on the atom-cavity interaction and the atomic spontaneous radiation can be effciently reduced since the cavity frequency is largely detuned from the atomic transition frequency.

  17. Evaluation of tooth preparations for Class II cavities using magnification loupes among dental interns and final year BDS students in preclinical laboratory

    Directory of Open Access Journals (Sweden)

    Khyati Narula

    2015-01-01

    Conclusions: Magnifying loupes help the dental students to have better vision, thus improved dexterity with hands while preparing the tooth for restoration. However, dental students have to get adapted to the loupes for the ease of using loupes. Using loupes frequently may help them to get adapted to the loupes.

  18. Influence of the power level of an ultra-sonic system on dental cavity preparation Influência do nível de potência de um sistema de ultra-som em preparos cavitários

    Directory of Open Access Journals (Sweden)

    Érika Botelho Josgrilberg

    2007-12-01

    Full Text Available The aim of this study was to evaluate the shape of dental cavities made with the CVDentus® system using different ultrasound power levels. One standard cavity was made on the buccal aspect of 15 bovine incisors with a CVDentus® cylindrical bur (82142. The sample was divided into three groups: G1 - ultrasound with power II; G2 - ultrasound with power III; and G3 - ultrasound with power IV. A standardizing device was used to obtain standardized preparations and ultrasound was applied during one minute in each dental preparation. The cavities were sectioned in the middle, allowing observation of the cavity’s profile with a magnifying glass, and width and depth measurement using the Leica Qwin program. The Kruskal-Wallis (p O objetivo deste estudo foi avaliar o formato dos preparos cavitários realizados com o sistema CVDentus® utilizando potências variadas do ultra-som. Uma cavidade padronizada foi realizada na face vestibular de 15 incisivos bovinos utilizando as pontas cilíndricas CVDentus® (82142. A amostra foi dividida em 3 grupos: G1 - ultra-som com potência II; G2 - ultra-som com potência III; e G3 - ultra-som com potência IV. Foi utilizada uma máquina padronizadora de preparos cavitários e o ultra-som foi aplicado durante 1 minuto em cada preparo. As cavidades foram seccionadas no centro, permitindo a visualização do perfil cavitário em uma lupa estereoscópica, e esse foi medido em largura e profundidade por meio do programa Leica Qwin. O teste estatístico Kruskal-Wallis (p < 0,05 e o método de Dunn demonstraram diferenças entre os formatos das cavidades produzidas com as potências III e IV. Entretanto, as cavidades realizadas com a potência III apresentaram dimensões semelhantes às da ponta utilizada. Concluiu-se que a potência indicada pelo fabricante (III é a mais adequada para uso do sistema CVDentus®.

  19. Cavity magnomechanics

    Science.gov (United States)

    Zhang, Xufeng; Zou, Changling; Jiang, Liang; Tang, Hong X.

    Mechanical oscillators have been recently widely utilized to couple with optical and microwave photons in a variety of hybrid quantum systems, but they all lack the tunability. The magnetostrictive force provides an alternative mechanism to allow phonon to couple with a different type of information carrier-magnon, the collective excitation of magnetization whose frequency can be tuned by a bias magnetic field. Here, we demonstrate an intriguing hybrid system that consists of a magnonic, a mechanical, and a microwave resonator. The magnon-phonon interaction results in hallmark coherent phenomena such as magnomechanically induced transparency/absorption and magnomechanical parametric amplification. The magnetic field dependence of magnon provides our system with unprecedented tunability. Moreover, the great flexibility of our system allows us to achieve triple resonance among magnon, phonon and photon, which drastically enhances the magnomechanical interaction. Our work demonstrates the fundamental principle of cavity magnetomechanics, opening up great opportunities in various applications, such as tunable microwave filter and amplifier, long-lifetime quantum memories, microwave-to-optics conversion.

  20. Observation of dressed intra-cavity dark states

    OpenAIRE

    Wang, Yanhua; Zhang, Jiepeng; Zhu, Yifu

    2011-01-01

    Cavity electromagnetically induced transparency in a coherently prepared cavity-atom system is manifested as a narrow transmission peak of a weak probe laser coupled into the cavity mode. We show that with a resonant pump laser coupling the cavity-confined four-level atoms from free space, the narrow transmission peak of the cavity EIT is split into two peaks. The two peaks represent the dressed intra-cavity dark states and have a frequency separation approximately equal to the Rabi frequency...

  1. Marginal microleakage in vitro study on class V cavities prepared with Er:YAG laser and etched with acid or etched with Er:YAG laser and acid; Estudo in vitro da microinfiltracao marginal em cavidades classe V preparadas com laser de Er:YAG e condicionadas com acido ou com laser de Er:YAG e acido

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Henrique Dutra Simoes

    2001-07-01

    Microleakage at the interface between the teeth and the restorative materials remains a problem with composite resin restorations. Microleakage at the gingival margins of class V cavities restorations still challenge as they are usually placed in dentin and/or cementum. Previous studies have shown that the cavity preparation with Er:YAG laser is possible. It has been reported that Er:YAG laser has ability to create irregular surface providing micromechanical retention for adhesive dental restorative materials and to improve marginal sealing. The purpose of this in vitro study was to evaluate the marginal microleakage on class V cavities prepared with Er:YAG laser and etched with acid or with Er:YAG laser and acid, in compared to those prepared and etched conventionally. Thirty human molars were divided into three groups, namely: group I - prepared with Er:YAG laser (KaVo KEY Laser II - Germany) and etched with 37% phosphoric acid; group II - prepared with Er:YAG laser and etched with Er:YAG laser and 37% phosphoric acid; group III (control group) - prepared with high speed drill and etched with 37% phosphoric acid. All cavities were treated with same adhesive system (Single Bond - 3M) and restored with the composite resin (Z100 - 3M), according to the manufacturer's instructions. The specimens were stored at 37 deg C in water for 24 hours, polished with Sof-Lex discs (3M), thermally stressed, sealed with a nail polish coating except for the area of the restoration and 1 mm around it, and immersed in a 50% aqueous solution of silver nitrate for 24 hours. After that, the specimens were rinsed in water, soaked in a photodeveloping solution and exposed to a fluorescent light for 8 hours. The teeth were embedded in an autopolymerizing resin and sectioned longitudinally using a diamond saw microtome under running water. The sections were photographed. The microleakage at the occlusal cavity and at the gingival margins of each specimen was evaluated with scores (0

  2. Efeitos Sazonais no Índice Bovespa

    OpenAIRE

    José Fajardo; Rafael Pereira

    2008-01-01

    Este artigo tem como objetivo investigar três anomalias no índice da Bolsa de Valores de São Paulo (BOVESPA): efeito dia da semana, reversão do efeito segunda-feira e efeito feriado. O período analisado é de Jan/1995 a Dez/2007, segmentando também em subperíodos de acordo com os mandatos presidenciais. O artigo aborda as teorias da eficiência de mercado e dos efeitos sazonais analisados. De acordo com as estatísticas as anomalias não foram constadas com constância durante os períodos estud...

  3. Crab Cavity Development

    CERN Document Server

    Calaga, R; Burt, G; Ratti, A

    2015-01-01

    The HL-LHC upgrade will use deflecting (or crab) cavities to compensate for geometric luminosity loss at low β* and non-zero crossing angle. A local scheme with crab cavity pairs across the IPs is used employing compact crab cavities at 400 MHz. Design of the cavities, the cryomodules and the RF system is well advanced. The LHC crab cavities will be validated initially with proton beam in the SPS.

  4. Cavity cooling below the recoil limit.

    Science.gov (United States)

    Wolke, Matthias; Klinner, Julian; Keßler, Hans; Hemmerich, Andreas

    2012-07-01

    Conventional laser cooling relies on repeated electronic excitations by near-resonant light, which constrains its area of application to a selected number of atomic species prepared at moderate particle densities. Optical cavities with sufficiently large Purcell factors allow for laser cooling schemes, avoiding these limitations. Here, we report on an atom-cavity system, combining a Purcell factor above 40 with a cavity bandwidth below the recoil frequency associated with the kinetic energy transfer in a single photon scattering event. This lets us access a yet-unexplored regime of atom-cavity interactions, in which the atomic motion can be manipulated by targeted dissipation with sub-recoil resolution. We demonstrate cavity-induced heating of a Bose-Einstein condensate and subsequent cooling at particle densities and temperatures incompatible with conventional laser cooling. PMID:22767925

  5. Niobium Cavity Electropolishing Modelling and Optimisation

    CERN Document Server

    Ferreira, L M A; Forel, S; Shirra, J A

    2013-01-01

    It’s widely accepted that electropolishing (EP) is the most suitable surface finishing process to achieve high performance bulk Nb accelerating cavities. At CERN and in preparation for the processing of the 704 MHz high-beta Superconducting Proton Linac (SPL) cavities a new vertical electropolishing facility has been assembled and a study is on-going for the modelling of electropolishing on cavities with COMSOL® software. In a first phase, the electrochemical parameters were taken into account for a fixed process temperature and flow rate, and are presented in this poster as well as the results obtained on a real SPL single cell cavity. The procedure to acquire the data used as input for the simulation is presented. The modelling procedure adopted to optimise the cathode geometry, aimed at a uniform current density distribution in the cavity cell for the minimum working potential and total current is explained. Some preliminary results on fluid dynamics is also briefly described.

  6. Scanning electron microscopy evaluation of the interaction pattern between dentin and resin after cavity preparation using Er:YAG laser; Avaliacao, atraves de microscopia eletronica de varredura, do padrao de interacao dentina-resina em cavidades preparadas com laser de Er:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Schein, Marcelo Thome

    2001-07-01

    The aim of this study was to describe the interaction pattern formed between dentin and resin on cavities prepared with an erbium laser (Er:YAG). The morphological aspect of the irradiated dentin after acid etching was also observed. Ten dentin disks were obtained from fresh extracted third molars. Each disk received two cavities, one prepared with a conventional high-speed drill, while the other cavity was obtained by the use of an Er:YAG laser (KaVo KEY Laser, KaVo Co.). The laser treatment was performed with 250 mJ/pulse, 4 Hz, non contact mode, focused beam, and a fine water mist was used. Five disks were prepared for morphological analysis of the acid etched dentin. The other five disks had their cavities restored with Single Bond (3M) followed by Z100 resin (3M). The specimens were observed under scanning electron microscopy after dentin-resin interface demineralization and deproteinization. It was observed that the morphological characteristics of the acid-etched irradiated dentin were not favorable to the diffusion of monomers through the collagen network. The dentin resin interfacial aspect of irradiated dentin, after acid etching, showed thin tags and scarce hybridization zones, which agreed with the morphology of the irradiated and acid-etched dentin substrate observed. (author)

  7. Preparação e caracterização de membranas assimétricas de poli (fluoreto de vinilideno suportadas em poliéster - I: efeito do tratamento térmico nas propriedades das membranas Preparation and characterization of asymmetric membranes of poly (vinylidene fluoride supported in polyester - I: effect of heat treatment in the properties of membranes

    Directory of Open Access Journals (Sweden)

    Mônica B. Thürmer

    2010-09-01

    Full Text Available O poli(fluoreto de vinilideno (PVDF é um polímero semicristalino contendo uma fase amorfa e uma cristalina. Essa característica é importante para o preparo de membranas assimétricas, pois a fase cristalina tem grande influência na formação da estrutura da membrana e a fase amorfa na porosidade. Membranas de PVDF foram preparadas pelo processo de inversão de fases e avaliadas quanto à permeabilidade e morfologia, bem como o efeito do tratamento térmico. Foram comparadas as seguintes membranas: membrana sem tratamento térmico, membrana com tratamento térmico e membrana comercial. Ensaios de resistência química, fluxo permeado de água a várias pressões, difusão de íons, Microscopia Eletrônica de Varredura (MEV, Calorimetria Exploratória Diferencial (DSC e Análise Termogravimétrica (TGA foram realizados para verificar o comportamento das membranas.Poly(Vinylidene Fluoride (PVDF is a semicrystalline polymer containing an amorphous and a crystalline phase. This characteristic is important for the preparation of asymmetric membranes, because the crystalline phase has great influence on the membranes structure, while the amorphous phase affects the porosity. PVDF membranes were prepared by the phase inversion process, which were then evaluated with regard to permeability and morphology, as well as the thermal treatment effect. The following membranes were compared: without thermal treatment, with thermal treatment and commercially-available membrane. The analysis of chemical resistance, water permeability flux to different pressures and diffusion of ions, in addition to studies with Scanning Electron Microscopy (SEM, Differential Scanning Calorimetry (DSC and Thermogravimetric Analysis (TGA, were performed to investigate the membranes properties.

  8. Efeito das condições de preparação na condutividade elétrica de blendas de poli(fluoreto de vinilideno e poli(o-metoxianilina Effect of preparation conditions on the electrical conductivity of blends of poly (vinylidene fluoride and poly(o-methoxyaniline

    Directory of Open Access Journals (Sweden)

    Luiz Francisco Malmonge

    1998-01-01

    Full Text Available Neste trabalho estudou-se o efeito das condições de preparação na condutividade elétrica de blendas condutoras de poli(fluoreto de vinilideno (PVDF com poli(o-metoxianilina (POMA. A condutividade elétrica e a qualidade dos filmes produzidos dependem significativamente do solvente, dopante e das condições de preparação das blendas. Filmes flexíveis e auto-sustentáveis da blenda PVDF/POMA dopada com o ácido p-tolueno sulfônico (TSA foram obtidos em condições otimizadas. Estes apresentam condutividade elétrica em uma larga faixa (10-12 - 10-2 S/cm, onde para baixos teores de POMA-TSA (In this work, the effect of preparation conditions on the properties of conductive blends of poly (vinylidene fluoride (PVDF and poly(o-methoxyaniline (POMA was studied. The quality and conductivity of the films produced depend significantly on the solvent, dopant and preparation conditions of the blends. Flexible, free-standing films of PVDF/POMA blends doped with p-toluene sulfonic acid (TSA were obtained in optimized conditions. These blends can exhibit electrical conductivity in a wide range (10-12 - 10-2 S/cm. Furthermore, relatively high conductivity values (10-7 S/cm are reached starting from low contents of POMA-TSA (<2,0% weight without definition of a percolation threshold.

  9. Superconducting crab cavity

    International Nuclear Information System (INIS)

    Complete overlapping of the electron and positron bunches at colliding point can be attained by using the strong time-depending electromagnetic RF field in the superconducting crab cavity. Commissioning of the crab cavities started in February 2007 at KEKB. Effective head-on collision of electron and positron has been achieved successfully. After introduction of crab crossing and crab cavity, the structure and the fabrication of the KEKB superconducting crab cavity are discussed. (author)

  10. RF Cavity Design

    CERN Document Server

    Jensen, E

    2014-01-01

    After a short overview of a general approach to cavity design, we sketch the derivation of waveguide modes from plane waves and of cavity fields from waveguide modes. The characteristic parameters describing cavities and their performance are defined and explained. An equivalent circuit is introduced and extended to explain beam loading and higher order modes. Finally travelling- and standing-wave multi-gap cavities are introduced using the Brillouin diagram.

  11. Scheme for Generation of Entanglement among Bimodal Cavities

    Institute of Scientific and Technical Information of China (English)

    SONG Xin-Guo; FENG Xun-Li

    2004-01-01

    @@ We present a scheme for generation of an entangled state in many spatially separated bimodal cavity modes via cavity quantum electrodynamics. A V-type three-level atom, initially prepared in a coherent superposition of its excited states, successively passes through both the bimodal cavities. If the atom is measured in its ground state after leaving the last cavity, an entangled state of many cavity modes can be generated. The conditions to generate the maximally entangled state with unity probability are worked out.

  12. Methyl biodiesel from Dipteryx lacunifera: preparation, characterization and effect of antioxidant on the oxidation stability; Biodiesel metilico de Dipteryx lacunifera: preparacao, caracterizacao e efeito de antioxidantes na estabilidade a oxidacao

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Francisca Diana da Silva; Moura, Carla Veronica Rodarte de; Chaves, Mariana H., E-mail: mariana@ufpi.edu.b [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Dept. de Quimica

    2010-07-01

    The objective of this work was to study the potentialities of Dipteryx lacunifera Ducke seeds oil for biodiesel production. The yield in oil was of 46.11 {+-} 0.37%. Methyl biodiesel was prepared by base catalyzed transesterification yielding 88.13% and percentage conversion of triglycerides to corresponding methyl ester of 89.1%. The addition of the tertiary butylhydroquinone (TBHQ, 50 ppm), butylated hydroxytoluene (BHT, 50 ppm) and cashew nut shell liquid (CNSL, 2000 ppm) antioxidants in the biodiesel contributed to the increase of the induction period of 2.97 h for 8.08; 6.06 and 6.02 h, respectively. (author)

  13. Beam cavity interaction

    CERN Document Server

    Gamp, A

    2011-01-01

    We begin by giving a description of the rf generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, rf feedback, and feed-forward are described. Examples of digital rf phase and amplitude control for the special case of superconducting cavities are also given. Finally, a dedicated phase loop for damping synchrotron oscillations is discussed.

  14. Cavity turnover and equilibrium cavity densities in a cottonwood bottomland

    Science.gov (United States)

    Sedgwick, James A.; Knopf, Fritz L.

    1992-01-01

    A fundamental factor regulating the numbers of secondary cavity nesting (SCN) birds is the number of extant cavities available for nesting. The number of available cavities may be thought of as being in an approximate equilibrium maintained by a very rough balance between recruitment and loss of cavities. Based on estimates of cavity recruitment and loss, we ascertained equilibrium cavity densities in a mature plains cottonwood (Populus sargentii) bottomland along the South Platte River in northeastern Colorado. Annual cavity recruitment, derived from density estimates of primary cavity nesting (PCN) birds and cavity excavation rates, was estimated to be 71-86 new cavities excavated/100 ha. Of 180 active cavities of 11 species of cavity-nesting birds found in 1985 and 1986, 83 were no longer usable by 1990, giving an average instantaneous rate of cavity loss of r = -0.230. From these values of cavity recruitment and cavity loss, equilibrium cavity density along the South Platte is 238-289 cavities/100 ha. This range of equilibrium cavity density is only slightly above the minimum of 205 cavities/100 ha required by SCN's and suggests that cavity availability may be limiting SCN densities along the South Platte River. We submit that snag management alone does not adequately address SCN habitat needs, and that cavity management, expressed in terms of cavity turnover and cavity densities, may be more useful.

  15. Retention proposal in complex cavities.

    Directory of Open Access Journals (Sweden)

    Pedro Alvarez Rodríguez

    2003-12-01

    Full Text Available Background: Dental Operatory is the main structure in which Odontology lies. It is not an easy discipline that gives enjoyable results with little effort due to the difficulties that a correct reconstruction of a destroyed dental element offers.The frequency with which pulpar injury occurs while anchoring additional retainers in complex cavities, the technical difficulties the lack of these devices cause and the need to simplify dental procedures lead this study to show the advantages to substitute additional retainers for a retainer surcus. Method: An observational descriptive study was applied to 53 patients(42% of the universe , sample which was selected by means of a simple randomized sample . From a proximal-occlusal cavity, the preparations were extended in a box-like shape towards the bucal or lingual region and the additional retainers were substituted for a surcus which was performed in the gingival wall of the preparation. Calcium Hydroxide of rapid dryness was used as a cavity cover and Policarboxilate cement as a base; then the amalgam restoration was performed. The number of restorations were studied taking into account the patient´s age and the failures due to fractures of amalgam, loss of vitality and periapical changes were assessed taking into consideration the patient´s age and a one- year follow up. Results: Most of the amalgam restorations were performed in patients aged from 35 to 59 years and the relative frequencies due to fractures of amalgam, loss of vitality and periapical changes were very low. Conclusion: The substitution of additional retainers for a retainer surcus in complex cavities of vital molars showed to be advantageous because it guarantees a less degree of pulpar damage and less pulpar damage.

  16. A database for superconducting cavities for the TESLA Test Facility

    Science.gov (United States)

    Gall, P. D.; Goessel, A.; Gubarev, V.; Iversen, J.

    2006-07-01

    We look back on 10 years experience using a database for superconducting cavities for the TESLA Test Facility (TTF). The database was developed to collect data of every preparation step and measurement in order to optimize cavity production and preparation techniques to meet the ambitious goal of high accelerating gradients at high quality factors. Data from 110 superconducting 9-cell cavities, 50 single cell cavities, several 2- to 7-cell cavities and about 60 RF couplers were collected in the database. In addition, company measurements on sub-assemblies and parts forming the next 30 9-cell cavities were stored, thus establishing the database as part of a quality management system. This database is dynamically accessible via an extensive graphical web-interface based on ORACLE products, which enables the users to select and analyse the collected data easily from anywhere.

  17. Superconducting cavity driving with FPGA controller

    Energy Technology Data Exchange (ETDEWEB)

    Czarski, T.; Koprek, W.; Pozniak, K.T.; Romaniuk, R.S. [Warsaw Univ. of Technology (Poland); Simrock, S.; Brand, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Chase, B.; Carcagno, R.; Cancelo, G. [Fermi National Accelerator Lab., Batavia, IL (United States); Koeth, T.W. [Rutgers - the State Univ. of New Jersey, NJ (United States)

    2006-07-01

    The digital control of several superconducting cavities for a linear accelerator is presented. The laboratory setup of the CHECHIA cavity and ACC1 module of the VU-FEL TTF in DESY-Hamburg have both been driven by a Field Programmable Gate Array (FPGA) based system. Additionally, a single 9-cell TESLA Superconducting cavity of the FNPL Photo Injector at FERMILAB has been remotely controlled from WUT-ISE laboratory with the support of the DESY team using the same FPGA control system. These experiments focused attention on the general recognition of the cavity features and projected control methods. An electrical model of the resonator was taken as a starting point. Calibration of the signal path is considered key in preparation for the efficient driving of a cavity. Identification of the resonator parameters has been proven to be a successful approach in achieving required performance; i.e. driving on resonance during filling and field stabilization during flattop time while requiring reasonable levels of power consumption. Feed-forward and feedback modes were successfully applied in operating the cavities. Representative results of the experiments are presented for different levels of the cavity field gradient. (orig.)

  18. Superconducting cavity driving with FPGA controller

    International Nuclear Information System (INIS)

    The digital control of several superconducting cavities for a linear accelerator is presented. The laboratory setup of the CHECHIA cavity and ACC1 module of the VU-FEL TTF in DESY-Hamburg have both been driven by a Field Programmable Gate Array (FPGA) based system. Additionally, a single 9-cell TESLA Superconducting cavity of the FNPL Photo Injector at FERMILAB has been remotely controlled from WUT-ISE laboratory with the support of the DESY team using the same FPGA control system. These experiments focused attention on the general recognition of the cavity features and projected control methods. An electrical model of the resonator was taken as a starting point. Calibration of the signal path is considered key in preparation for the efficient driving of a cavity. Identification of the resonator parameters has been proven to be a successful approach in achieving required performance; i.e. driving on resonance during filling and field stabilization during flattop time while requiring reasonable levels of power consumption. Feed-forward and feedback modes were successfully applied in operating the cavities. Representative results of the experiments are presented for different levels of the cavity field gradient. (orig.)

  19. Tooth structure and fracture strength of cavities

    DEFF Research Database (Denmark)

    Mondelli, José; Sene, Fábio; Ramos, Renata Pereira;

    2007-01-01

    (Groups I, II and III) and indirect inlay cavities (Groups IV, V and VI) were prepared maintaining standardized dimensions: 2-mm deep pulpal floors, 1.5-mm wide gingival walls and 2-mm high axial walls. Buccolingual width of the occlusal box was established at 1/4 (Groups I and IV), 1/3 (Groups II and V...... a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed by two-way ANOVA and Tukey test (alpha= 0.05). 1/4-inlay cavities had higher percent mean mass loss (9.71%) than composite resin cavities with the same width (7.07%). 1/3-inlay preparations also produced higher percent mean...... mass loss (13.91%) than composite resin preparations with the same width (10.02%). 1/2-inlay cavities had 21.34% of mass loss versus 16.19% for the 1/2-composite resin cavities. Fracture strength means (in kgf) were: GI = 187.65; GII = 143.62; GIII = 74.10; GIV = 164.22; GV = 101.92; GVI = 50...

  20. Electromagnetic SCRF Cavity Tuner

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, V.; Borissov, E.; Foster, G.W.; Makulski, A.; Pischalnikov, Y.; Khabiboulline, T.; /Fermilab

    2009-05-01

    A novel prototype of SCRF cavity tuner is being designed and tested at Fermilab. This is a superconducting C-type iron dominated magnet having a 10 mm gap, axial symmetry, and a 1 Tesla field. Inside the gap is mounted a superconducting coil capable of moving {+-} 1 mm and producing a longitudinal force up to {+-} 1.5 kN. The static force applied to the RF cavity flanges provides a long-term cavity geometry tuning to a nominal frequency. The same coil powered by fast AC current pulse delivers mechanical perturbation for fast cavity tuning. This fast mechanical perturbation could be used to compensate a dynamic RF cavity detuning caused by cavity Lorentz forces and microphonics. A special configuration of magnet system was designed and tested.

  1. LEP copper accelerating cavities

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    These copper cavities were used to generate the radio frequency electric field that was used to accelerate electrons and positrons around the 27-km Large Electron-Positron (LEP) collider at CERN, which ran from 1989 to 2000. The copper cavities were gradually replaced from 1996 with new superconducting cavities allowing the collision energy to rise from 90 GeV to 200 GeV by mid-1999.

  2. Optically measuring interior cavities

    Science.gov (United States)

    Stone, Gary Franklin

    2009-11-03

    A method of measuring the three-dimensional volume or perimeter shape of an interior cavity includes the steps of collecting a first optical slice of data that represents a partial volume or perimeter shape of the interior cavity, collecting additional optical slices of data that represents a partial volume or perimeter shape of the interior cavity, and combining the first optical slice of data and the additional optical slices of data to calculate of the three-dimensional volume or perimeter shape of the interior cavity.

  3. Efeito da linhaça (Linum usitatissimum L. sob diferentes formas de preparo na resposta biológica em ratos Effect of flaxseed (Linum usitatissimum L. prepared by different methods on the biological response of rats

    Directory of Open Access Journals (Sweden)

    Anne y Castro Marques

    2011-02-01

    Full Text Available OBJETIVO: Verificar as possíveis atividades biológicas causadas pelo consumo diário de linhaça em diferentes condições de preparo, em ratos Wistar machos recém-desmamados. MÉTODOS: Os ratos recém-desmamados (n=32 foram divididos em 4 grupos de 8 animais: ração padrão; ração com 16% de grão de linhaça cru; ração com 16% de grão de linhaça assado; e ração com 7% de óleo de linhaça. Os animais foram pesados a cada três dias e, após 23 dias de período experimental, foram sacrificados por punção cardíaca, sendo os órgãos imediatamente pesados e o sangue coletado e armazenado a -18ºC para realização das análises (glicose, colesterol total, lipoproteína de alta densidade - colesterol, triglicerídios e proteínas totais. As fezes foram coletadas para a determinação de umidade, lipídeo excretado e lipídeo absorvido. RESULTADOS: Não houve diferença entre os grupos quanto ao ganho de peso total, consumo diário, coeficiente de eficácia alimentar e peso dos órgãos. A excreção diária, o teor de umidade das fezes e a quantidade de lipídeo fecal foram maiores nos grupos linhaça cru e linhaça assada em comparação aos grupos padrão e óleo de linhaça. Com exceção do lipoproteína de alta densidade-colesterol, todos os demais parâmetros bioquímicos avaliados apresentaram diferenças estatísticas entre os tratamentos. CONCLUSÃO: O consumo de linhaça, seja como grão cru, assado ou óleo, possui atividade biológica em ratos, destacando-se por reduzir os níveis de glicose, triglicerídios e colesterol. Além disso, o consumo do grão de linhaça aumentou significativamente o volume do bolo fecal e a excreção de lipídeos nas fezes.OBJECTIVE: The objective of this investigation was to evaluate the effects of flaxseed (Linum usitatissimum L. prepared by different methods on the biological response of rats. METHODS: Weaned rats (n=32 were divided into 4 groups of 8 animals each: standard feed, standard

  4. SPS accelerating cavity

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    One of the SPS accelerating cavities (200 MHz, travelling wave structure). The power that is fed into the upstream end of the cavity is extracted at the downstream end and sent into a dump load. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8011289, 8302397.

  5. SPS accelerating cavity

    CERN Multimedia

    1980-01-01

    One of the SPS acceleration cavities (200 MHz, travelling wave structure). On the ceiling one sees the coaxial transmission line which feeds the power from the amplifier, located in a surface building above, to the upstream end of the cavity. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8104138, 8302397.

  6. Superconducting RF cavities

    CERN Document Server

    Bernard, Philippe

    1999-01-01

    It was 20 years ago when the research and development programme for LEP superconducting cavities was initiated. It lasted about 10 years. Today, my aim is not to tell you in great detail about the many innovations made thanks to our research, but I would like to point out some milestones in the development of superconducting cavities where Emilio's influence was particularly important.

  7. Ferrite loaded rf cavity

    International Nuclear Information System (INIS)

    The mechanism of a ferrite-loaded rf cavity is explained from the point of view of its operation. Then, an analysis of the automatic cavity-tuning system is presented using the transfer function; and a systematic analysis of a beam-feedback system using transfer functions is also presented. (author)

  8. Superconducting cavities for LEP

    CERN Multimedia

    1983-01-01

    Above: a 350 MHz superconducting accelerating cavity in niobium of the type envisaged for accelerating electrons and positrons in later phases of LEP. Below: a small 1 GHz cavity used for investigating the surface problems of superconducting niobium. Albert Insomby stays on the right. See Annual Report 1983 p. 51.

  9. Passivated niobium cavities

    Science.gov (United States)

    Myneni, Ganapati Rao; Hjorvarsson, Bjorgvin; Ciovati, Gianluigi

    2006-12-19

    A niobium cavity exhibiting high quality factors at high gradients is provided by treating a niobium cavity through a process comprising: 1) removing surface oxides by plasma etching or a similar process; 2) removing hydrogen or other gases absorbed in the bulk niobium by high temperature treatment of the cavity under ultra high vacuum to achieve hydrogen outgassing; and 3) assuring the long term chemical stability of the niobium cavity by applying a passivating layer of a superconducting material having a superconducting transition temperature higher than niobium thereby reducing losses from electron (cooper pair) scattering in the near surface region of the interior of the niobium cavity. According to a preferred embodiment, the passivating layer comprises niobium nitride (NbN) applied by reactive sputtering.

  10. Efeito da adição de dopantes durante a síntese do precursor columbita para a preparação da cerâmica ferroelétrica relaxora PMN Effect of the doping addition in the synthesis of the columbite precursor for preparation of the PMN relaxor ferroelectric ceramic

    Directory of Open Access Journals (Sweden)

    A. A. Cavalheiro

    1999-12-01

    Full Text Available O Niobato de Chumbo e Magnésio (PMN é um material que possui propriedades ferroelétricas de relaxação. Essa propriedade pode ser acentuada ou alterada mediante a adição de dopantes. Neste trabalho foi demonstrado como a adição dos íons Ba2+/Ti4+ e Pb2+/Ti4+, ou somente o íon K+, altera as características do precursor columbita obtido pelo método Pechini e da cerâmica PMN. Através da análise dos resultados obtidos por DRX e IV, constatou-se que a dopagem com os pares de íons Ba2+/Ti4+ e Pb2+/Ti4+ leva à retenção de maior quantidade de matéria orgânica nos carvões precursores e à formação de fases secundárias. Quando adiciona-se somente o íon K+, o comportamento do precursor columbita é similar ao puro. No entanto, seus efeitos positivos podem ser verificados na cerâmica PMN, como o aumento no tamanho de grão e a elevação em Tm.Lead Magnesium Niobate (PMN is a ferroelectric with relaxation properties. These properties can be improved or modified by doping. In this work is showed that Ba2+/Ti4+ and Pb2+/Ti4+ ions or only K+ ion change the characteristics of columbite precursor prepared by Pechini’s method. The results obtained by XRD and FT-IR show that there is more retention of organic matter in the Ba2+/Ti4+ and Pb2+/Ti4+-MN doped precursors than in the pure one. It was also possible to show that K+-MN doped powders exhibit characteristics similar to pure MN powder, but in the PMN ceramic there is positive effects. The size grain and Tm increase when K+ ion is used on the PMN synthesis.

  11. SPS RF Accelerating Cavity

    CERN Multimedia

    1979-01-01

    This picture shows one of the 2 new cavities installed in 1978-1979. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also increased: to the first 2 MW plant a second 2 MW plant was added and by end 1979 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X

  12. SPS RF Cavity

    CERN Multimedia

    1975-01-01

    The picture shows one of the two initially installed cavities. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also gradually increased: by end 1980 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412017X, 7411048X, 7505074.

  13. Efeitos do Kinesio Taping no Desporto

    OpenAIRE

    Pereira, Marcelo

    2012-01-01

    O médico japonês, Dr. Kenzo Kase criou, em 1973, o kinesio taping, uma nova aplicação de ligadura adesiva, tendo como objectivo melhorar a função da musculatura, sem limitar os movimentos, reduzir a dor, edema e os espasmos musculares. Parece ter também a capacidade de prevenir lesões no desporto, sendo por isso uma técnica comummente utilizada para este efeito. Objetivo: Esta revisão bibliográfica teve como propósito destacar os principais dados publicados sobre o efeito do Kinesio Taping no...

  14. Hydroforming of elliptical cavities

    Science.gov (United States)

    Singer, W.; Singer, X.; Jelezov, I.; Kneisel, P.

    2015-02-01

    Activities of the past several years in developing the technique of forming seamless (weldless) cavity cells by hydroforming are summarized. An overview of the technique developed at DESY for the fabrication of single cells and multicells of the TESLA cavity shape is given and the major rf results are presented. The forming is performed by expanding a seamless tube with internal water pressure while simultaneously swaging it axially. Prior to the expansion the tube is necked at the iris area and at the ends. Tube radii and axial displacements are computer controlled during the forming process in accordance with results of finite element method simulations for necking and expansion using the experimentally obtained strain-stress relationship of tube material. In cooperation with industry different methods of niobium seamless tube production have been explored. The most appropriate and successful method is a combination of spinning or deep drawing with flow forming. Several single-cell niobium cavities of the 1.3 GHz TESLA shape were produced by hydroforming. They reached accelerating gradients Eacc up to 35 MV /m after buffered chemical polishing (BCP) and up to 42 MV /m after electropolishing (EP). More recent work concentrated on fabrication and testing of multicell and nine-cell cavities. Several seamless two- and three-cell units were explored. Accelerating gradients Eacc of 30 - 35 MV /m were measured after BCP and Eacc up to 40 MV /m were reached after EP. Nine-cell niobium cavities combining three three-cell units were completed at the company E. Zanon. These cavities reached accelerating gradients of Eacc=30 - 35 MV /m . One cavity is successfully integrated in an XFEL cryomodule and is used in the operation of the FLASH linear accelerator at DESY. Additionally the fabrication of bimetallic single-cell and multicell NbCu cavities by hydroforming was successfully developed. Several NbCu clad single-cell and double-cell cavities of the TESLA shape have been

  15. Cavity-enhanced spectroscopies

    CERN Document Server

    van Zee, Roger

    2003-01-01

    ""Cavity-Enhanced Spectroscopy"" discusses the use of optical resonators and lasers to make sensitive spectroscopic measurements. This volume is written by the researcchers who pioneered these methods. The book reviews both the theory and practice behind these spectroscopic tools and discusses the scientific discoveries uncovered by these techniques. It begins with a chapter on the use of optical resonators for frequency stabilization of lasers, which is followed by in-depth chapters discussing cavity ring-down spectroscopy, frequency-modulated, cavity-enhanced spectroscopy, intracavity spectr

  16. SPS RF cavity

    CERN Multimedia

    1974-01-01

    The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. A power of up to 790 kW can be supplied to each giving a total accelerating voltage of about 8 MV. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities.

  17. RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland

    2014-09-21

    Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Part of the problem is that RF breakdown in an evacuated cavity involves a complex mixture of effects, which include the geometry, metallurgy, and surface preparation of the accelerating structures and the make-up and pressure of the residual gas in which plasmas form. Studies showed that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas, as needed for muon cooling channels, without the need for long conditioning times, even in the presence of strong external magnetic fields. This positive result was expected because the dense gas can practically eliminate dark currents and multipacting. In this project we used this high pressure technique to suppress effects of residual vacuum and geometry that are found in evacuated cavities in order to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. One of the interesting and useful outcomes of this project was the unanticipated collaborations with LANL and Fermilab that led to new insights as to the operation of evacuated normal-conducting RF cavities in high external magnetic fields. Other accomplishments included: (1) RF breakdown experiments to test the effects of SF6 dopant in H2 and He gases with Sn, Al, and Cu electrodes were carried out in an 805 MHz cavity and compared to calculations and computer simulations. The heavy corrosion caused by the SF6 components led to the suggestion that a small admixture of oxygen, instead of SF6, to the hydrogen would allow the same advantages without the corrosion in a practical muon beam line. (2) A

  18. REFRIGERAÇÃO UTILIZANDO PASTILHAS DE EFEITO PELTIER

    OpenAIRE

    Antonio Luiz P. S. Campos; Aécio Vinícius Amorim Farias; Jainne Daniele F. S. Fernandes; Alailson de Freitas Braz; Ludmila Sayonara S. X. Machado; Edfranklin de Souza Pimentel

    2010-01-01

    Pastilhas de Peltier são dispositivos baseados no efeito Peltier e são aplicadas para produzir efeito refrigerador ou aquecedor. Este trabalho aborda conceitos envolvidos na fabricação e funcionamento desses dispositivos tais como: histórico do efeito Peltier e desenvolvimento de placas de efeito Peltier. É feito um estudo de eficiência da refrigeração de água utilizando uma placa de efeito Peltier existente no Campus Natal – Zona Norte. Para isso, é implementada uma estrutura de refrigeração...

  19. SPS accelerating cavity

    CERN Multimedia

    1983-01-01

    See photo 8202397: View towards the downstream end of one of the SPS accelerating cavities (200 MHz, travelling wave structure). See 7603195 and 8011289 for more details, 7411032 for the travelling wave structure, and also 8104138.

  20. SPS accelerating cavity

    CERN Multimedia

    1983-01-01

    View towards the downstream end of one of the SPS accelerating cavities (200 MHz, travelling wave structure). See 7603195 and 8011289 for more details, 7411032 for the travelling wave structure, and also 8104138.

  1. accelerating cavity from LEP

    CERN Multimedia

    This is an accelerating cavity from LEP, with a layer of niobium on the inside. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment. These challenging requirements pushed European industry to new achievements. 256 of these cavities are now used in LEP to double the energy of the particle beams.

  2. Moving Detectors in Cavities

    CERN Document Server

    Obadia, N

    2007-01-01

    We consider two-level detectors, coupled to a quantum scalar field, moving inside cavities. We highlight some pathological resonant effects due to abrupt boundaries, and decide to describe the cavity by switching smoothly the interaction by a time-dependent gate-like function. Considering uniformly accelerated trajectories, we show that some specific choices of non-adiabatic switching have led to hazardous interpretations about the enhancement of the Unruh effect in cavities. More specifically, we show that the emission/absorption ratio takes arbitrary high values according to the emitted quanta properties and to the transients undergone at the entrance and the exit of the cavity, {\\it independently of the acceleration}. An explicit example is provided where we show that inertial and uniformly accelerated world-lines can even lead to the same ``pseudo-temperature''.

  3. SPS accelerating cavity

    CERN Multimedia

    1976-01-01

    The SPS started up with 2 accelerating cavities (each consisting of 5 tank sections) in LSS3. They have a 200 MHz travelling wave structure (see 7411032 and 7802190) and 750 kW of power is fed to each of the cavities from a 1 MW tetrode power amplifier, located in a surface building above, via a coaxial transmission line. Clemens Zettler, builder of the SPS RF system, is standing at the side of one of the cavities. In 1978 and 1979 another 2 cavities were added and entered service in 1980. These were part of the intensity improvement programme and served well for the new role of the SPS as proton-antiproton collider. See also 7411032, 8011289, 8104138, 8302397.

  4. Melatonin and Oral Cavity

    OpenAIRE

    Murat İnanç Cengiz; Seda Cengiz; Hom-Lay Wang

    2012-01-01

    While initially the oral cavity was considered to be mainly a source of various bacteria, their toxins and antigens, recent studies showed that it may also be a location of oxidative stress and periodontal inflammation. Accordingly, this paper focuses on the involvement of melatonin in oxidative stress diseases of oral cavity as well as on potential therapeutic implications of melatonin in dental disorders. Melatonin has immunomodulatory and antioxidant activities, stimulates the proliferatio...

  5. Oral cavity and leprosy

    OpenAIRE

    Shambulingappa Pallagatti; Soheyl Sheikh; Anupreet Kaur; Amit Aggarwal; Ravinder Singh2

    2012-01-01

    Although leprosy involves the oral cavity in up to 60% of the patients, examination of the oral cavity in leprosy clinics or oral health science clinics is often neglected. Oral involvement in leprosy can broadly be divided into non-specific and specific lesions. In this review, we discuss various oral manifestations in leprosy patients so as to increase the awareness about this aspect among dermatologists and dental surgeons.

  6. Hydroforming of Elliptical Cavities

    OpenAIRE

    W. Singer; Singer, X.; Jelezov, I.; Kneisel, P.

    2015-01-01

    Activities of the past several years in developing the technique of forming seamless (weldless) cavity cells by hydroforming are summarized. An overview of the technique developed at DESY for the fabrication of single cells and multicells of the TESLA cavity shape is given and the major rf results are presented. The forming is performed by expanding a seamless tube with internal water pressure while simultaneously swaging it axially. Prior to the expansion the tube is necked at the iris area ...

  7. Hybrid vertical cavity laser

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2010-01-01

    A new hybrid vertical cavity laser structure for silicon photonics is suggested and numerically investigated. It incorporates a silicon subwavelength grating as a mirror and a lateral output coupler to a silicon ridge waveguide.......A new hybrid vertical cavity laser structure for silicon photonics is suggested and numerically investigated. It incorporates a silicon subwavelength grating as a mirror and a lateral output coupler to a silicon ridge waveguide....

  8. Cavity Optomechanics at Millikelvin Temperatures

    Science.gov (United States)

    Meenehan, Sean Michael

    The field of cavity optomechanics, which concerns the coupling of a mechanical object's motion to the electromagnetic field of a high finesse cavity, allows for exquisitely sensitive measurements of mechanical motion, from large-scale gravitational wave detection to microscale accelerometers. Moreover, it provides a potential means to control and engineer the state of a macroscopic mechanical object at the quantum level, provided one can realize sufficiently strong interaction strengths relative to the ambient thermal noise. Recent experiments utilizing the optomechanical interaction to cool mechanical resonators to their motional quantum ground state allow for a variety of quantum engineering applications, including preparation of non-classical mechanical states and coherent optical to microwave conversion. Optomechanical crystals (OMCs), in which bandgaps for both optical and mechanical waves can be introduced through patterning of a material, provide one particularly attractive means for realizing strong interactions between high-frequency mechanical resonators and near-infrared light. Beyond the usual paradigm of cavity optomechanics involving isolated single mechanical elements, OMCs can also be fashioned into planar circuits for photons and phonons, and arrays of optomechanical elements can be interconnected via optical and acoustic waveguides. Such coupled OMC arrays have been proposed as a way to realize quantum optomechanical memories, nanomechanical circuits for continuous variable quantum information processing and phononic quantum networks, and as a platform for engineering and studying quantum many-body physics of optomechanical meta-materials. However, while ground state occupancies (that is, average phonon occupancies less than one) have been achieved in OMC cavities utilizing laser cooling techniques, parasitic absorption and the concomitant degradation of the mechanical quality factor fundamentally limit this approach. On the other hand, the high

  9. Metasurface external cavity laser

    Science.gov (United States)

    Xu, Luyao; Curwen, Christopher A.; Hon, Philip W. C.; Chen, Qi-Sheng; Itoh, Tatsuo; Williams, Benjamin S.

    2015-11-01

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  10. Metasurface external cavity laser

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Luyao, E-mail: luyaoxu.ee@ucla.edu; Curwen, Christopher A.; Williams, Benjamin S. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, California 90095 (United States); Hon, Philip W. C.; Itoh, Tatsuo [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Chen, Qi-Sheng [Northrop Grumman Aerospace Systems, Redondo Beach, California 90278 (United States)

    2015-11-30

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  11. Experimental investigation of cavity flows

    Energy Technology Data Exchange (ETDEWEB)

    Loeland, Tore

    1998-12-31

    This thesis uses LDV (Laser Doppler Velocimetry), PIV (Particle Image Velocimetry) and Laser Sheet flow Visualisation to study flow inside three different cavity configurations. For sloping cavities, the vortex structure inside the cavities is found to depend upon the flow direction past the cavity. The shape of the downstream corner is a key factor in destroying the boundary layer flow entering the cavity. The experimental results agree well with numerical simulations of the same geometrical configurations. The results of the investigations are used to find the influence of the cavity flow on the accuracy of the ultrasonic flowmeter. A method to compensate for the cavity velocities is suggested. It is found that the relative deviation caused by the cavity velocities depend linearly on the pipe flow. It appears that the flow inside the cavities should not be neglected as done in the draft for the ISO technical report on ultrasonic flowmeters. 58 refs., 147 figs., 2 tabs.

  12. SPS accelerating cavity

    CERN Multimedia

    1983-01-01

    See photo 8302397: View from the downstream end of one of the SPS accelerating cavities (200 MHz, travelling wave structure). See 7603195 and 8011289 for more details, 7411032 for the travelling wave structure, and also 8104138. Giacomo Primadei stands on the left.

  13. Laser cavity modelling

    OpenAIRE

    Damakoa, I.; Audounet, J.; Bouyssou, G.; Vassilieff, G.

    1993-01-01

    Two approachs of modelling nonhomogeneous cavity laser are presented. They are based on the beam propagation method which allows the use of fast Fourier transform (FFT). The resulting procedures provide selfconsistent solutions to the Maxwell and diffusion equations. Results are given to illustrate the two methods.


  14. LEP superconducting cavity

    CERN Multimedia

    1995-01-01

    Engineers work in a clean room on one of the superconducting cavities for the upgrade to the LEP accelerator, known as LEP-2. The use of superconductors allow higher electric fields to be produced so that higher beam energies can be reached.

  15. Cavity launchers for ICRF

    International Nuclear Information System (INIS)

    A type of resonant coil cavity is analyzed as a launcher for ICRF. This approach offers the advantages of: (1) convenient and flexible sizing, (2) ease of operation and maintenance, and (3) high power handling capability. We present results for resonance conditions, mode structures, power handling capabilities, and sensitivity to variation in plasma parameters

  16. Statistical electromagnetics: Complex cavities

    NARCIS (Netherlands)

    Naus, H.W.L.

    2008-01-01

    A selection of the literature on the statistical description of electromagnetic fields and complex cavities is concisely reviewed. Some essential concepts, for example, the application of the central limit theorem and the maximum entropy principle, are scrutinized. Implicit assumptions, biased choic

  17. What's a Cavity?

    Science.gov (United States)

    ... and deeper over time. Cavities are also called dental caries (say: KARE-eez), and if you have a ... made up mostly of the germs that cause tooth decay. The bacteria in your mouth make acids and when plaque clings to your teeth, the acids can eat away at the outermost ...

  18. Niobium superconducting cavity

    CERN Multimedia

    1980-01-01

    This 5-cell superconducting cavity, made from bulk-Nb, stems from the period of general studies, not all directed towards direct use at LEP. This one is dimensioned for 1.5 GHz, the frequency used at CEBAF and also studied at Saclay (LEP RF was 352.2 MHz). See also 7908227, 8007354, 8209255, 8210054, 8312339.

  19. Implosion of the small cavity and large cavity cannonball targets

    International Nuclear Information System (INIS)

    Recent results of cannonball target implosion research are briefly reviewed with theoretical predictions for GEKKO XII experiments. The cannonball targets are classified into two types according to the cavity size ; small cavity and large cavity. The compression mechanisms of the two types are discussed. (author)

  20. Sensitivity of Niobium Superconducting RF Cavities to Magnetic Field

    CERN Document Server

    Gonnella, Dan

    2015-01-01

    Future particle accelerators such as the the SLAC "Linac Coherent Light Source-II" (LCLS-II) and the proposed Cornell Energy Recovery Linac (ERL) require hundreds of superconducting RF (SRF) cavities operating in continuous wave (CW) mode. In order to achieve economic feasibility of projects such as these, the cavities must achieve a very high intrinsic quality factor (Q0). In order to reach these high Q0's in the case of LCLS-II, nitrogen-doping has been proposed as a cavity preparation technique. When dealing with Q0's greater than 1x10^10, the effects of ambient magnetic field on Q0 become significant. Here we show that the sensitivity that a cavity has to ambient magnetic field is highly dependent on the cavity preparation. Specifically, standard electropolished and 120C baked cavities show a sensitivity of ~0.8 and ~0.6 nOhm/mG trapped, respectively, while nitrogen-doped cavities show a sensitivity of ~2 to 5 nOhm/mG trapped. Less doping results in weaker sensitivity. This difference in sensitivities is ...

  1. Open Microwave Cavity for use in a Purcell Enhancement Cooling Scheme

    CERN Document Server

    Evetts, N; Bizzotto, D; Longuevergne, D; Hardy, W N

    2016-01-01

    A microwave cavity is described which can be used to cool lepton plasmas for potential use in synthesis of antihydrogen. The cooling scheme is an incarnation of the Purcell Effect: when plasmas are coupled to a microwave cavity, the plasma cooling rate is resonantly enhanced through increased spontaneous emission of cyclotron radiation. The cavity forms a three electrode section of a Penning-Malmberg trap and has a bulged cylindrical geometry with open ends aligned with the magnetic trapping axis. This allows plasmas to be injected and removed from the cavity without the need for moving parts while maintaining high quality factors for resonant modes. The cavity includes unique surface preparations for adjusting the cavity quality factor and achieving anti-static shielding using thin layers of nichrome and colloidal graphite respectively. Geometric design considerations for a cavity with strong cooling power and low equilibrium plasma temperatures are discussed. Cavities of this weak-bulge design will be appli...

  2. Hollow waveguide cavity ringdown spectroscopy

    Science.gov (United States)

    Dreyer, Chris (Inventor); Mungas, Greg S. (Inventor)

    2012-01-01

    Laser light is confined in a hollow waveguide between two highly reflective mirrors. This waveguide cavity is used to conduct Cavity Ringdown Absorption Spectroscopy of loss mechanisms in the cavity including absorption or scattering by gases, liquid, solids, and/or optical elements.

  3. Engineering three-dimensional maximally entangled states for two modes in a bimodal cavity

    Institute of Scientific and Technical Information of China (English)

    Yang Zhen-Biao; Su Wan-Jun

    2007-01-01

    An alternative scheme is proposed for engineering three-dimensional maximally entangled states for two modes of a superconducting microwave cavity. In this scheme, an appropriately prepared four-level atom is sent through a bimodal cavity. During its passing through the cavity, the atom is coupled resonantly with two cavity modes simultaneously and addressed by a classical microwave pulse tuned to the required transition. Then the atomic states are detected to collapse two modes onto a three-dimensional maximally entangled state. The scheme is different from the previous one in which two nonlocal cavities are used. A comparison between them is also made.

  4. Colloquium: cavity optomechanics

    CERN Multimedia

    2011-01-01

    Monday 14 November 2011, 17:00 Ecole de Physique, Auditoire Stueckelberg Université de Genève Cavity optomechanics: controlling micro mechanical oscillators with laser light Prof. Tobias Kippenberg EPFL, Lausanne Laser light can be used to cool and to control trapped ions, atoms and molecules at the quantum level. This has lead to spectacular advances such as the most precise atomic clocks. An outstanding frontier is the control with lasers of nano- and micro-mechancial systems. Recent advances in cavity optomechanics have allowed such elementary control for the first time, enabling mechanical systems to be ground state cooled leading to readout with quantum limited sensitivity and permitting to explore new device concepts resulting from radiation pressure.  

  5. Cavity cooling and normal-mode spectroscopy of a bound atom-cavity system

    International Nuclear Information System (INIS)

    Full text: Single atoms strongly coupled to the field of an optical cavity form an attractive system for the realization of an atom-light interface useful for quantum information protocols. An experimental implementation of these schemes requires atoms which are trapped, cooled and localized in the cavity mode at a region of strong coupling. In the experiment presented here, single atoms are trapped and stored in a far-detuned intracavity dipole trap. We demonstrate cavity cooling by illuminating the system with a weak, slightly blue-detuned light beam. This extends the storage time of an atom, which is limited by parametric heating from fluctuations of the intracavity dipole trap, by more than a factor of two. The observed cooling force is of Sisyphus-type and was predicted. A special feature of this force is that it does not rely on the spontaneous emission of a photon by the atom, and therefore the cooling force is at least five times larger than the force achievable for free-space cooling methods with comparable excitation of a two-level atom. Preparing single atoms strongly-coupled to the mode of a high-finesse cavity in this way, we observe two well-resolved normal-mode peaks both in transmission of the cavity as well as in the trap lifetime. The experimental data agree well with a Monte Carlo simulation, demonstrating the localization of the atom to within a tenth of a wavelength at a cavity antinode. The ability to individually excite the normal modes of a bound atom-cavity system shows that we have reached good control over this fundamental quantum system. (author)

  6. RF superconducting cavities

    CERN Document Server

    Kojima, Y

    1980-01-01

    The history and present activity in research on RF superconducting cavities in various countries are reviewed. The program of the July 1980 Karlsruhe workshop is reproduced and research activity in this field at Stanford HEPL and SLAC, Cornell, Oregon, Brookhaven, KEK (Japan), Weismann (Israel), Genoa, CERN and Karlsruhe (KfK) listed. The theoretical basis of surface resistance and intracavity magnetic field, multipacing and non-resonant electron loading are outlined. (20 refs).

  7. Entangling atoms in bad cavities

    OpenAIRE

    Sorensen, Anders S.; Molmer, Klaus

    2002-01-01

    We propose a method to produce entangled spin squeezed states of a large number of atoms inside an optical cavity. By illuminating the atoms with bichromatic light, the coupling to the cavity induces pairwise exchange of excitations which entangles the atoms. Unlike most proposals for entangling atoms by cavity QED, our proposal does not require the strong coupling regime g^2/\\kappa\\Gamma>> 1, where g is the atom cavity coupling strength, \\kappa is the cavity decay rate, and \\Gamma is the dec...

  8. Cavity Backed Slot Antenna

    Directory of Open Access Journals (Sweden)

    Sarang Masani, Ila Parmar, Hitendra Jadeja

    2013-05-01

    Full Text Available Among the current driving forces in wireless communications, there is a need for compact, efficient, inexpensive and reproducible antennas. In some instances, particularly long-distance applications, radiators with directive, high-gain characteristics are necessary. This paper proposes a cavity-backed slot antenna to that end. This antenna will enhance the gain, directivity and can also be easily flush mounted to the flying object. The shape and size of the slot can be effectively utilized to get the desired result. The proposed antenna is feed by waveguide which facilitate it to be applicable at high power operation where coaxial cable fails due to skin effect. Present antenna is verified using Numerical Technique called Finite Element Method FEM. The conception of this antenna is realized by the software HFSS “Ansoft-High Frequency Structure Simulator”. By properly selecting shapes, dimensions of the slots and number of slot affects the parameters like return loss, gain along Θ, Ø directions, Cartesian plot and radiation pattern .The Backing of cavity to the slot antenna provide the basics of the gain enhancement and the slot loading effect and the cavity volume plays an important role in achieving the desired return loss at the specific frequency.The simulated antenna shows the 7.0944 db of gain and return loss of -28.60. The proposed antenna works at 6 GHz.

  9. Morphological evaluation of cavity preparation surface after duraphat and Er:YAG laser treatment by scanning electronic microscopy; Avaliacao das alteracoes morfologicas da superficie do preparo cavitario apos condicionamento com verniz fluoretado a 2,26 % e laser de Er:YAG atraves de microscopia eletronica de varredura

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Luciane Borelli

    2002-07-01

    The treatment of dental surface using different lasers to prevent dental caries has been studied for several on last years. The purpose of this in vitro study was to evaluate the morphological changes on dentin surface from pulpal wall of cavity preparations performed by high-speed drill, treated with 2,26% fluoride varnish (Duraphat) and Er:YAG laser, and then submitted after receiving or not to EDTA 15% treatment. Twenty Class V cavities were performed on ten humans molars. The specimens were randomly divided in to 4 groups: group 1- treatment with Duraphat followed by Er:YAG laser irradiation (120 mJ/ 4 Hz); group 2: Er:YAG laser irradiation, same parameters, followed by Duraphat treatment; group 3- same group 1 followed by immersion in EDTA (5 min); group 4 - same as group 2 followed by immersion in EDTA (5 min). The specimens were processed for SEM analysis. The micrographs showed that Duraphat treatment promoted morphological changes on dentin, closing dentinal tubules; the specimens treated by Duraphat and Er:YAG laser and immersed in EDTA (group 3) showed homogeneous surface, closed and protected dentinal tubules, maintenance of the fluoride varnish on the dentin surface and around the dentinal tubules, showing feasible and efficiency of these therapies the feasibility.(author)

  10. Crab Cavities for Linear Colliders

    International Nuclear Information System (INIS)

    Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

  11. Crab Cavities for Linear Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Burt, G.; Ambattu, P.; Carter, R.; Dexter, A.; Tahir, I.; /Cockcroft Inst. Accel. Sci. Tech. /Lancaster U.; Beard, C.; Dykes, M.; Goudket, P.; Kalinin, A.; Ma, L.; McIntosh, P.; /Daresbury; Shulte, D.; /CERN; Jones, Roger M.; /Cockcroft Inst. Accel. Sci. Tech. /Manchester U.; Bellantoni, L.; Chase, B.; Church, M.; Khabouline, T.; Latina, A.; /Fermilab; Adolphsen, C.; Li, Z.; Seryi, Andrei; /SLAC

    2011-11-08

    Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

  12. Crab cavities for linear colliders

    CERN Document Server

    Burt, G; Carter, R; Dexter, A; Tahir, I; Beard, C; Dykes, M; Goudket, P; Kalinin, A; Ma, L; McIntosh, P; Shulte, D; Jones, Roger M; Bellantoni, L; Chase, B; Church, M; Khabouline, T; Latina, A; Adolphsen, C; Li, Z; Seryi, Andrei; Xiao, L

    2008-01-01

    Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

  13. REFRIGERAÇÃO UTILIZANDO PASTILHAS DE EFEITO PELTIER

    Directory of Open Access Journals (Sweden)

    Antonio Luiz P. S. Campos

    2010-06-01

    Full Text Available Pastilhas de Peltier são dispositivos baseados no efeito Peltier e são aplicadas para produzir efeito refrigerador ou aquecedor. Este trabalho aborda conceitos envolvidos na fabricação e funcionamento desses dispositivos tais como: histórico do efeito Peltier e desenvolvimento de placas de efeito Peltier. É feito um estudo de eficiência da refrigeração de água utilizando uma placa de efeito Peltier existente no Campus Natal – Zona Norte. Para isso, é implementada uma estrutura de refrigeração de água e são feitas medições para determinar a eficiência de sistema. Por fim, são apresentadas conclusões sobre o estudo desenvolvido.

  14. Measurement-induced macroscopic superposition states in cavity optomechanics

    CERN Document Server

    Hoff, Ulrich B; Neergaard-Nielsen, Jonas S; Andersen, Ulrik L

    2016-01-01

    We present a novel proposal for generating quantum superpositions of macroscopically distinct states of a bulk mechanical oscillator, compatible with existing optomechanical devices operating in the readily achievable bad-cavity limit. The scheme is based on a pulsed cavity optomechanical quantum non-demolition (QND) interaction, driven by displaced non-Gaussian states, and measurement-induced feedback, avoiding the need for strong single-photon optomechanical coupling. Furthermore, we show that single-quadrature cooling of the mechanical oscillator is sufficient for efficient state preparation, and we outline a three-pulse protocol comprising a sequence of QND interactions for squeezing-enhanced cooling, state preparation, and tomography.

  15. Electro Polishing of Niobium Cavities at DESY

    CERN Document Server

    Matheisen, A; Morales, H; Petersen, B; Schmoekel, M; Steinhau-Kühl, N

    2004-01-01

    At DESY a facility for electro polishing (EP) of the super conducting (s.c.) TESLA/TTF cavities have been built and is operational since summer 2003. The EP infrastructure is capable to handle single-cell structures and the standard TESLA/ TTF nine-cell cavities. Several electro polishing processes have been made since and acceleration voltage up to 40 MV/m have been reached in nine cell structures. We report on measurements and experiences gained since 2003 as well as on handling procedures developed for the preparation of electro polished resonators. Specific data like heat production, variation of current density and bath aging will be presented. Another important point for reproducible results is the quality control of the electro polishing process. First quality control steps to be implanted in the EP procedure for large-scale production will be described.

  16. Centrifugal barrel polishing of 1.3 GHz Nb cavities

    International Nuclear Information System (INIS)

    Superconducting radio-frequency (SRF) cavities are the key components of particle accelerators such as the European X-ray Free Electron Laser (XFEL, under construction) and the planned future International Linear Collider (ILC). Steady progress in surface treatment techniques of SRF cavities in both the achievable quality factor Q and the accelerating electric field Eacc makes new accelerators and ambitious projects feasible. One of the alternative surface preparation techniques which is actually being explored is centrifugal barrel polishing (CBP) pioneered at KEK in Japan in mid-nineties by T. Hiuchi et al. CBP is a mechanical polishing of cavities and results in around 10 x smaller surface roughness and mirror-like surface as compared to chemistry alone. Q and Eacc are expected to be at least as high as for chemically treated cavities. CBP eliminates the bulk chemistry and has the potential to completely replace the chemistry. The University of Hamburg is installing a CBP machine to study it as a cavity preparation and repair technique for 9-cell 1.3 GHz SRF cavities at the Deutsche Elektronen-Synchrotron (DESY). The setup and first commissioning tests will be presented and discussed.

  17. ISR RF cavities

    CERN Multimedia

    1983-01-01

    In each ISR ring the radiofrequency cavities were installed in one 9 m long straight section. The RF system of the ISR had the main purpose to stack buckets of particles (most of the time protons)coming from the CPS and also to accelerate the stacked beam. The installed RF power per ring was 18 kW giving a peak accelerating voltage of 20 kV. The system had a very fine regulation feature allowing to lower the voltage down to 75 V in a smooth and well controlled fashion.

  18. Surface preparation of niobium

    International Nuclear Information System (INIS)

    Any discussion of surface preparation for superconducting rf-surfaces is certainly connected with the question what is the best recipe for achieving high Q-values and high break-down fields. Since the break-down in a cavity is not understood so far and because several mechanisms play a role, it also is not possible to give one recipe which always works. Nevertheless in the past certain preparation techniques for niobium surfaces have been developed and certain rules for preparation can be applied. In the following the to-days state of the art will be described and it is attempted to give a short description of the surface in conjunction with the methods of surface treatments, which generally can be applied to niobium cavities. (orig./WTR)

  19. In situ Measurements of the SPS 200MHz Accelerating Cavity III

    CERN Document Server

    Kramer, Patrick; Caspers, Fritz; Vollinger, Christine; Montesinos, Eric; CERN. Geneva. ATS Department

    2015-01-01

    The main 200MHz travelling wave RF system of the SPS consists of two 5-tank and two 4-tank cavities. This system will be modified during LS 2, and the preparation work has already started. The 5 tank 200MHz travelling wave cavity III was measured in reflection. This Internal Note presents results obtained for the matching of cavity and feeder line, by looking at both frequency and time domain data. Techniques for estimating the feeder line attenuation are also presented.

  20. Frequency control of radiofrequency cavity

    OpenAIRE

    Menart, Jure

    2014-01-01

    This work describes the design, development and application of the system for frequency control of EMMA accelerator radiofrequency cavity. The problem with the radiofrequency cavities is, that because of various factors (change in the environmental temperature, mechanical stress, ...), they are continuously frequency detuning. The consequence of the frequency detuning is that electromagnetic field in the cavity is not optimal for the acceleration of the particles. For this reason the resonant...

  1. Generation of GHZ-type and \\emph{W}-type entangled coherent states of three-cavity fields

    CERN Document Server

    Yuan, C H; Zhang, Z M; Yuan, Chun-Hua; Ou, Yong-Cheng; Zhang, Zhi-Ming

    2005-01-01

    We present experimental schemes to prepare the three-cavity GHZ-type and \\emph{W}-type entangled coherent states in the context of dispersive cavity quantum electrodynamics. The schemes can be easily generalized to prepare the GHZ-type and \\emph{W}-type entangled coherent states of $n$-cavity fields. The discussion of our schemes indicates that it can be realized by current technologies.

  2. Single ion cavity QED experiments

    International Nuclear Information System (INIS)

    Full text: We have set up a spherical Paul trap for a storing a single Ca+ ion placed in the center of a high finesse near confocal resonator. We report on experiments demonstrating the coupling of the narrow S1/2-D5/2 transition to the cavity internal light field. Due to the coupling, the ion acts as sensitive probe for the cavity internal field. We are able to map the field distribution by measuring the excitation probability. Scanning the cavity over the resonance imprints a Doppler frequency shift on the cavity field which leads to a spectral shift and a asymmetric broadening of the S-D transition. (author)

  3. Cavity coalescence in superplastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Stowell, M.J.; Livesey, D.W.; Ridley, N.

    1984-01-01

    An analysis of the probability distribution function of particles randomly dispersed in a solid has been applied to cavitation during superplastic deformation and a method of predicting cavity coalescence developed. Cavity size distribution data were obtained from two microduplex nickel-silver alloys deformed superplastically to various extents at elevated temperature, and compared to theoretical predictions. Excellent agreement occurred for small void sizes but the model underestimated the number of voids in the largest size groups. It is argued that the discrepancy results from a combination of effects due to non-random cavity distributions and to enhanced growth rates and incomplete spheroidization of the largest cavities.

  4. Surface state photonic bandgap cavities

    OpenAIRE

    Rahachou, A. I.; Zozoulenko, I. V.

    2005-01-01

    We propose and analyze a new type of a resonant high-Q cavity for lasing, sensing or filtering applications, which is based on a surface states of a finite photonic crystal. We demonstrate that such the cavity can have a Q factor comparable with that one of conventional photonic band-gap defect mode cavities. At the same time, the distinguished feature of the surface mode cavity is that it is situated directly at the surface of the photonic crystal. This might open up new possibilities for de...

  5. Nanofriction in Cavity Quantum Electrodynamics.

    Science.gov (United States)

    Fogarty, T; Cormick, C; Landa, H; Stojanović, Vladimir M; Demler, E; Morigi, Giovanna

    2015-12-01

    The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics. PMID:26684118

  6. High temperature heat treatment of 3 GHz niobium cavities

    International Nuclear Information System (INIS)

    We applied high temperature heat treatment to 3 GHz cavities to determine the preparation of niobium cavities using the titanium solid-state gettering process. Some preliminary results showed peak surface electric fields of up to 65 MV/m at a Q-factor of 2 x 1010. We evaluated improvement in the purity of the niobium by measuring the residual resistance ratio (RRR) at 10 K. The purest niobium we prepared reached a RRR of 670. To study the potential application to large-scale accelerator structures at lower frequencies, we are testing the possibility of heat treating the cavity half-cells before welding them. Therefore, we investigated the influence of electron beam welding on the RRR of high-purity niobium. In this paper we present the results of the investigations. (Author)3 figs., 2 tabs., 10 refs

  7. High temperature heat treatment of 3GHz niobium cavities

    International Nuclear Information System (INIS)

    We applied high temperature heat treatment to 3GHz cavities to determine the preparation of niobium cavities using the titanium solid-state gettering process. Some preliminary results showed peak surface electric fields of up to 65MV/m at a Q-factor of 2xlO10. We evaluated improvement in the purity of the niobium by measuring the residual resistance ratio (RRR) at 10K. The purest niobium we prepared reached a RRR of 670. To study the potential application to large-scale accelerator structures at lower frequencies, we are testing the possibility of heat treating the cavity half-cells before welding them. Therefore, we investigated the influence of electron beam welding on the RRR of high-purity niobium

  8. Two-cavity gyroklystron with self-excited input cavity

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, E.V.; Zasypkin, E.V. [Inst. of Applied Physics, Novgorod (Russian Federation)

    1995-12-31

    A new type of gyro-oscillator-two cavity gyroklystron with self-excited input cavity (or, for simplicity, two-cavity gyrokylstron oscillator) is proposed. In this device, the autooscillations excited in the first cavity modulate electrons by energy, electrons are bunched in the drift space, and then the bunches excite powerful oscillations in the second (output) cavity. Since, as in gyroklystron, the optimal second cavity length L{sub 2} does not exceed 2-2.5 {lambda} ({lambda} is the operating wavelength), its Q-factor Q{sub 2} {approximately} (L{sub 2}/{lambda}){sup 2} should be essentially lower than cavity Q-factor of a traditional gyrotron. It allows to diminish the RF ohmic losses in the second cavity and to enhance the output power without the efficiency reduction. A simplest theory of such oscillator has been developed. Predicted by theory, the output power enhancement (in comparison with that for an ordinary gyrotron) has been demonstrated experimentally.

  9. The quest for high-gradient superconducting cavities

    International Nuclear Information System (INIS)

    Superconducting RF cavities excel in applications requiring continuous waves or long pulse voltages. Since power losses in the walls of the cavity increase as the square of the accelerating voltage, copper cavities become uneconomical as demand for high continuous wave voltage grows with particle energy. For these reasons, RF superconductivity has become an important technology for high energy and high luminosity accelerators. The state of art in performance of sheet metal niobium cavities is best represented by the statistics of more than 300 5-cell, 1.5-GHz cavities built for CEBAF. Key aspects responsible for the outstanding performance of the CEBAF cavities set are the anti-multipactor, elliptical cell shape, good fabrication and welding techniques, high thermal conductivity niobium, and clean surface preparation. On average, field emission starts at the electric field of 8.7 MV/m, but there is a large spread, even though the cavities received nominally the same surface treatment and assembly procedures. In some cavities, field emission was detected as low as 3 MV/m. In others, it was found to be as high as 19 MV/m. As we will discuss, the reason for the large spread in the gradients is the large spread in emitter characteristics and the random occurrence of emitters on the surface. One important phenomenon that limits the achievable RF magnetic field is thermal breakdown of superconductivity, originating at sub-millimeter-size regions of high RF loss, called defects. Simulation reveal that if the defect is a normal conducting region of 200 mm radius, it will break down at 5 MV/m. Producing high gradients and high Q in superconducting cavities demands excellent control of material properties and surface cleanliness. The spread in gradients that arises from the random occurrence of defects and emitters must be reduced. It will be important to improve installation procedures to preserve the excellent gradients now obtained in laboratory test in vertical cryostats

  10. A Scanning Cavity Microscope

    CERN Document Server

    Mader, Matthias; Hänsch, Theodor W; Hunger, David

    2014-01-01

    Imaging of the optical properties of individual nanosystems beyond fluorescence can provide a wealth of information. However, the minute signals for absorption and dispersion are challenging to observe, and only specialized techniques requiring sophisticated noise rejection are available. Here we use signal enhancement in a scanning optical microcavity to demonstrate ultra-sensitive imaging. Harnessing multiple interactions of probe light with a sample within an optical resonator, we achieve a 1700-fold signal enhancement compared to diffraction-limited microscopy. We demonstrate quantitative imaging of the extinction cross section of gold nanoparticles with a sensitivity below 1 nm2, we show a method to improve spatial resolution potentially below the diffraction limit by using higher order cavity modes, and we present measurements of the birefringence and extinction contrast of gold nanorods. The demonstrated simultaneous enhancement of absorptive and dispersive signals promises intriguing potential for opt...

  11. Fiber cavities for atom chips

    OpenAIRE

    Klappauf, B.G.; Horak, P.; Kazansky, P. G.

    2003-01-01

    We present experimental realizations of several micro-cavities, constructed from standard fiber optic components, which meet the theoretical criteria for single atom detection from laser-cooled samples. We discuss integration of these cavities into state-of-the-art 'atom chips'.

  12. Design of a cavity filter

    International Nuclear Information System (INIS)

    A cavity filter was developed for the SSRF 0-mode beam feedback. The filter is used to pick up the 500 MHz signal from the storage ring beam. The Superfish was used to simulate the model of the cavity bandpass filter. The design method, parameters of the filter and results of beam measurements are described in this paper. (authors)

  13. Study on superconducting accelerating cavities

    International Nuclear Information System (INIS)

    A test cavity of cylindrical shape has been designed and constructed to study superconducting accelerating cavities for TRISTAN e+e- Ring. Higher order modes have been calculated by using SUPERFISH program and an analytical method, and measured. The measured resonant frequencies well agree with the calculated results. (author)

  14. Technical tasks in superconducting cavities

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Kenji [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

    1997-11-01

    The feature of superconducting rf cavities is an extremely small surface resistance on the wall. It brings a large energy saving in the operation, even those are cooled with liquid helium. That also makes possible to operate themselves in a higher field gradient comparing to normal conducting cavities, and brings to make accelerators compact. These merits are very important for the future accelerator engineering which is planed at JAERI for the neutron material science and nuclear waste transmutation. This machine is a high intensity proton linac and uses sc cavities in the medium and high {beta} sections. In this paper, starting R and D of proton superconducting cavities, several important technical points which come from the small surface resistance of sc cavities, are present to succeed it and also differences between the medium and high - {beta} structures are discussed. (author)

  15. Mechanical Properties of Niobium Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Ciovati, Gianluigi [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Dhakal, Pashupati [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Matalevich, Joseph R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Myneni, Ganapati Rao [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2015-09-01

    The mechanical stability of bulk Nb cavity is an important aspect to be considered in relation to cavity material, geometry and treatments. Mechanical properties of Nb are typically obtained from uniaxial tensile tests of small samples. In this contribution we report the results of measurements of the resonant frequency and local strain along the contour of single-cell cavities made of ingot and fine-grain Nb of different purity subjected to increasing uniform differential pressure, up to 6 atm. Measurements have been done on cavities subjected to different heat treatments. Good agreement between finite element analysis simulations and experimental data in the elastic regime was obtained with a single set of values of Young’s modulus and Poisson’s ratio. The experimental results indicate that the yield strength of medium-purity ingot Nb cavities is higher than that of fine-grain, high-purity Nb.

  16. Entanglement Transfer Between Cavity Fields and Excitons in a Driven Quantum Dot System

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We investigate entanglement transfer from two separate cavities to the excitons in two quantum dots separately placed in the two cavities. The cavity fields and the excitons are treated as two continuous-variable (CV) subsystems. The time-dependent characteristic functions in the Wigner representation for the two subsystems are analytically obtained. Under the conditions that one of the two CV subsystems is initially prepared in a two-mode squeezed vacuum state and the other in its lowest energy state, we show that the entanglement reciprocation between the cavity Reids and the excitons is realizable.

  17. Entanglement reciprocation between two charge qubits and two-cavity field

    Institute of Scientific and Technical Information of China (English)

    Hui-ping CUI; Yan SHAN; Jian ZOU; Bin SHAO

    2008-01-01

    We propose a simple scheme to generate twomode entangled coherent state in two separated cavities and realize the entanglement reciprocation between the superconducting charge qubits and continuous-variable system.By measuring the state of charge qubits,we find that the entanglement of two charge qubits,which are initially prepared in the maximally entangled state,can be transferred to the two-cavity field,and at this time the two-cavity field is in the entangled coherent state.We also find that the entanglement can be retrieved back to the two charge qubits after measuring the state of the two-cavity field.

  18. An Automated 476 MHz RF Cavity Processing Facility at SLAC

    CERN Document Server

    McIntosh, P; Schwarz, H

    2003-01-01

    The 476 MHz accelerating cavities currently used at SLAC are those installed on the PEP-II B-Factory collider accelerator. They are designed to operate at a maximum accelerating voltage of 1 MV and are routinely utilized on PEP-II at voltages up to 750 kV. During the summer of 2003, SPEAR3 will undergo a substantial upgrade, part of which will be to replace the existing 358.54 MHz RF system with essentially a PEP-II high energy ring (HER) RF station operating at 476.3 MHz and 3.2 MV (or 800 kV/cavity). Prior to installation, cavity RF processing is required to prepare them for use. A dedicated high power test facility is employed at SLAC to provide the capability of conditioning each cavity up to the required accelerating voltage. An automated LabVIEW based interface controls and monitors various cavity and test stand parameters, increasing the RF fields accordingly such that stable operation is finally achieved. This paper describes the high power RF cavity processing facility, highlighting the features of t...

  19. Field dependent surface resistance of niobium on copper cavities

    Science.gov (United States)

    Junginger, T.

    2015-07-01

    The surface resistance RS of superconducting cavities prepared by sputter coating a niobium film on a copper substrate increases significantly stronger with the applied rf field compared to cavities of bulk material. A possible cause is that the thermal boundary resistance between the copper substrate and the niobium film induces heating of the inner cavity wall, resulting in a higher RS. Introducing helium gas in the cavity, and measuring its pressure as a function of applied field allowed to conclude that the inner surface of the cavity is heated up by less than 120 mK when RS increases with Eacc by 100 n Ω . This is more than one order of magnitude less than what one would expect from global heating. Additionally, the effects of cooldown speed and low temperature baking have been investigated in the framework of these experiments. It is shown that for the current state of the art niobium on copper cavities there is only a detrimental effect of low temperature baking. A fast cooldown results in a lowered RS.

  20. Cavity-assisted quantum bath engineering

    Science.gov (United States)

    Murch, Kater

    2013-03-01

    In practice, quantum systems are never completely isolated, but instead interact with degrees of freedom in the surrounding environment, eventually leading to decoherence. Precision measurement techniques such as nuclear magnetic resonance and interferometry, as well as envisioned quantum schemes for computation, simulation, and data encryption, rely on the ability to prepare and preserve delicate quantum superpositions and entanglement. The conventional route to long-lived quantum coherence involves minimizing coupling to a dissipative bath. Paradoxically, it is possible to instead engineer specific couplings to a quantum environment that allow dissipation to actually preserve coherence. I will discuss our recent demonstration of quantum bath engineering for a superconducting qubit coupled to a microwave cavity. By tailoring the spectrum of microwave photon shot noise in the cavity, we create a dissipative environment that autonomously relaxes the qubit to an arbitrarily specified coherent superposition of the ground and excited states. In the presence of background thermal excitations, this mechanism increases the state purity and effectively cools the dressed atom state to a low temperature. We envision that future multi-qubit implementations could enable the preparation of entangled many-body states suitable for quantum simulation and computation. This work was supported by the IARPA CSQ program.

  1. Practical scheme for remote preparation of a photon-photon entangled state

    Institute of Scientific and Technical Information of China (English)

    Tan Jia; Fang Mao-Fa

    2006-01-01

    We present a scheme to remotely prepare a photon-photon entangled state via entanglement swapping in cavity QED. Using two successive processes of appropriate atom-cavity interaction and subsequent measurements, we obtain the entangled state with certain probability.

  2. Preparation and Application of the Prussian Blue/Chitosan Hybrid Film Modified Zinc Oxide Cavities Array/Indium-Tin Oxide Electrode%普鲁士蓝/壳聚糖杂化膜修饰氧化锌球腔阵列/氧化铟锡电极制备及应用

    Institute of Scientific and Technical Information of China (English)

    周宇; 朱庆亮; 尹凡; 孙磊; 周丽娟; 刘亚娟

    2012-01-01

    用Langmuir-Blodgett技术制成了附着聚苯乙烯小球的氧化铟锡(InSnO)模板。将此模板水平置于由硝酸锌及柠檬酸组成的前驱体溶胶中,用溶胶-凝胶法制得氧化锌球腔阵列/氧化铟锡电极。采用电沉积法得到普鲁士蓝/壳聚糖杂化膜修饰的氧化锌球腔阵列/氧化铟锡电极。该电极在pH 7.0~8.0的溶液中具有良好的电化学活性,过氧化氢浓度在7.67×10-7~4.72×10-4mol.L-1范围内与相应的电流响应值呈线性关系,检出限(3S/N)为2.4×10-7mol.L-1。测定2.0×10-5mol.L-1过氧化氢溶液时,其相对标准偏差(n=10)为3.8%。%A pattern plate of indium-tin oxide (InSnO) fixed with polystyrene microballs was prepared by applying the Langmuir-Blodgette technique. The pattern plate was placed horizontally into a precuisor sol containing Zn(NO3 )2 and citric acid, and the ZnO cavities array/InSnO electrode was prepared by the Sol-Jel method. The prussian blue (PB)/chitosan hybrid film modified ZnO cavities array/InSnO electrode was obtained by electrode- position technique. This modified electrode showed good electrochemical activity in solution of pH 7.0-8. 0, and linear relationship was obtained between values of response current and concentration of Hz 02 in the range of 7. 67 × 10^-7-4. 72×10^-4mol·L^-1 , with detection limit (3S/N) of 2.4×10^-7mol · L^-1. Value of RSD (n=10) found in determination of 2.0× 10^-5mol· L^-1 H2O2 was 3.8 %.

  3. Frequency-feedback cavity enhanced spectrometer

    Science.gov (United States)

    Hovde, David Christian; Gomez, Anthony

    2015-08-18

    A spectrometer comprising an optical cavity, a light source capable of producing light at one or more wavelengths transmitted by the cavity and with the light directed at the cavity, a detector and optics positioned to collect light transmitted by the cavity, feedback electronics causing oscillation of amplitude of the optical signal on the detector at a frequency that depends on cavity losses, and a sensor measuring the oscillation frequency to determine the cavity losses.

  4. Cavity beam position monitors

    International Nuclear Information System (INIS)

    Beam-based alignment and feedback systems are essential for the operation of future linear colliders and free electron lasers. A certain number of beam position monitors with a resolution in the submicron range are needed at selected locations. Most beam position monitors detect the electric or the magnetic field excited by a beam of charged particles at different locations around the beam pipe. In resonant monitors, however, the excitation of special field configurations by an off-center beam is detected. These structures offer a large signal per micron displacement. This paper is an attempt to summarize the fundamental characteristics of resonant monitors, their advantages and shortcomings. Emphasis will be on the design of cylindrical cavities, in particular on the estimation of expected signals, of resolution limits and the resulting beam distortion. This includes also a short introduction into numerical methods. Fabrication, tuning, and other practical problems will be reviewed briefly. Finally, some resonant devices used for beam position diagnostics will be discussed and listed

  5. Three-dimensional cavity calculations

    International Nuclear Information System (INIS)

    The existence of a code that solves for the resonant electromagnetic modes of oscillation in arbitrarily-shaped three-dimensional cavities opens new possibilities in rf-structure analysis and research. The URMEL-3D code, the product of a multi-year collaboration between DESY, KFA-Juelich, and Los Alamos, has been used in some exploratory studies to determine the feasibility of using a 3-D code to calculate the properties of several practical rf structures. The results are reported here for three cases: the jungle gym, two coupled cavities, and a waveguide-cavity coupling problem

  6. Beam - cavity interaction beam loading

    International Nuclear Information System (INIS)

    The interaction of a beam with a cavity and a generator in cyclic accelerators or storage rings is investigated. Application of Maxwell's equations together with the nonuniform boundary condition allows one to get an equivalent circuit for a beam-loaded cavity. The general equation for beam loading is obtained on the basis of the equivalent circuit, and the beam admittance is calculated. Formulas for power consumption by a beam-loaded cavity are derived, and the optimal tuning and coupling factor are analyzed. (author)

  7. New thin film techniques for SC cavities and photo cathodes

    CERN Document Server

    Antoine, C Z

    2013-01-01

    The EuCARD monograph 12, ¨Materials and surface aspects in the development of SRF niobium cavities¨ is a comprehensive review on the state of the art materials and material preparation for SRF cavities, and includes a chapter on state of the art film technology, paving the ground for future research and development. This chapter focuses on innovative multi-layered films to overcome materials limitation at high field, and on innovative coating technologies for traditional materials, and is the basis for the future Thin Film Task in Eucard-2.

  8. A polarization converter array using a twisted-azimuthal liquid crystal in cylindrical polymer cavities.

    Science.gov (United States)

    Wang, Xiahui; Xu, Miao; Ren, Hongwen; Wang, Qionghua

    2013-07-01

    We report a simple method to prepare an array of polarization converters using a twisted-azimuthal nematic liquid crystal (NLC) in cylindrical polymer cavities. When a NLC is filled in a cylindrical polymer cavity, LC in the cavity presents concentrically circular orientations. By treating LC on one side of the cavity with homogeneous alignment, a twisted-azimuthal texture is formed. Such a LC texture can convert a linear polarization light to either radial or azimuthal polarization light depending on the polarization direction of the incident light. The LC surface on the other side of the cavity is convex, so the light after passing through the cavity can be focused as well. The LC texture can be fixed firmly using polymer network. In comparison with previous polarization converters, our polarization converter has the merits of individually miniature size, array of pattern, and lens character. Our polarization converter array has potential applications in tight focusing, imaging, and material processing. PMID:23842407

  9. Transferring a cavity field entangled state in cavity QED

    Energy Technology Data Exchange (ETDEWEB)

    Ye Liu [Anhui Key Laboratory of Information Material and Devices, School of Physics and Material Science, Anhui University, Hefei 230039 (China); Guo Guangcan [Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026 (China)

    2005-08-01

    We propose a scheme for transferring an entanglement of zero- and one-photon states from one cavity to another. The scheme, which has 100% success probability, is mainly based on a two-mode cavity dispersively interacting with a three-level atom in the {lambda} configuration and does not involve Bell-state measurement. This scheme can also be used to teleport an unknown atomic state.

  10. SRF Cavity Fabrication and Materials

    CERN Document Server

    Singer, W

    2014-01-01

    The technological and metallurgical requirements of material for highgradient superconducting cavities are described. High-purity niobium, as the preferred metal for the fabrication of superconducting accelerating cavities, should meet exact specifications. The content of interstitial impurities such as oxygen, nitrogen, and carbon must be below 10μg/g. The hydrogen content should be kept below 2μg/g to prevent degradation of the Q-value under certain cool-down conditions. The material should be free of flaws (foreign material inclusions or cracks and laminations) that can initiate a thermal breakdown. Defects may be detected by quality control methods such as eddy current scanning and identified by a number of special methods. Conventional and alternative cavity fabrication methods are reviewed. Conventionally, niobium cavities are fabricated from sheet niobium by the formation of half-cells by deep drawing, followed by trim machining and Electron-Beam Welding (EBW). The welding of half-cells is a delicate...

  11. Niobium LEP 2 accelerating cavities

    CERN Multimedia

    An accelerating cavity from LEP. This could be cut open to show the layer of niobium on the inside. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment. These challenging requirements pushed European industry to new achievements. 256 of these cavities were used in an upgrade of the LEP accelerator to double the energy of the particle beams.

  12. Geometry-Invariant Resonant Cavities

    CERN Document Server

    Liberal, Iñigo; Engheta, Nader

    2015-01-01

    Resonant cavities are one of the basic building blocks in various disciplines of science and technology, with numerous applications ranging from abstract theoretical modeling to everyday life devices. The eigenfrequencies of conventional cavities are a function of its geometry, and, thus, the size and shape of a resonant cavity is selected in order to operate at a specific frequency. Here, we demonstrate theoretically the existence of geometry-invariant resonant cavities, i.e., resonators whose eigenfrequency is invariant with respect to geometrical deformations. This effect is obtained by exploiting the unusual properties of zero-index metamaterials, which enable decoupling of the time and spatial field variations. This new class of resonators may inspire alternative design concepts, and it might lead to the first generation of deformable resonant devices.

  13. CRAB Cavity in CERN SPS

    International Nuclear Information System (INIS)

    Beam collisions with a crossing angle at the interaction point are often necessary in colliders to reduce the effects of parasitic collisions which induce emittance growth and decrease beam lifetime. The crossing angle reduces the geometrical overlap of the beams and hence the luminosity. Crab cavity offer a promising way to compensate the crossing angle and to realize effective head-on collisions. Moreover, the crab crossing mitigates the synchro-betatron resonances due to the crossing angle. A crab cavity experiment in SPS is proposed as a proof of principle before deciding on a full crab-cavity implementation in the LHC. In this paper, we investigate the effects of a single crab cavity on beam dynamics in the SPS and life time.

  14. LEP Radio Frequency Copper Cavities

    CERN Multimedia

    The pulse of a particle accelerator. 128 of these radio frequency cavities were positioned around CERN's 27-kilometre LEP ring to accelerate electrons and positrons. The acceleration was produced by microwave electric oscillations at 352 MHz. The electrons and positrons were grouped into bunches, like beads on a string, and the copper sphere at the top stored the microwave energy between the passage of individual bunches. This made for valuable energy savings as it reduced the heat generated in the cavity.

  15. Single and Coupled Nanobeam Cavities

    DEFF Research Database (Denmark)

    Ivinskaya, Aliaksandra; Lavrinenko, Andrei; Shyroki, Dzmitry M.; A. Sukhorukov, Andrey

    This book collects chapters on different theoretical and experimental aspects of photonics crystals for Nanophotonics applications. It is divided in two parts - a theoretical section and an experimental and applicative section. The first part includes chapters developing several numerical methods...... for analysis and design of photonic crystal devices, such as 2D ring resonators for filters, single and coupled nanobeam cavities, birefringence in photonic crystal cavities, threshold analysis in photonic crystal lasers, gap solitons in photonic crystals, novel photonic atolls, dynamic...

  16. RRR Characteristics for SRF Cavities

    OpenAIRE

    Jung, Yoochul; Hyun, Myungook; Joung, Mijoung

    2015-01-01

    The first heavy ion accelerator is being constructed by the rare isotope science project (RISP) launched by the Institute of Basic Science (IBS) in South Korea. Four different types of superconducting cavities were designed, and prototypes were fabricated such as a quarter wave resonator (QWR), a half wave resonator (HWR) and a single spoke resonator (SSR). One of the critical factors determining performances of the superconducting cavities is a residual resistance ratio (RRR). The RRR values...

  17. Chá verde brasileiro (Camellia sinensis var assamica: efeitos do tempo de infusão, acondicionamento da erva e forma de preparo sobre a eficiência de extração dos bioativos e sobre a estabilidade da bebida Brazilian green tea (Camellia sinensis var assamica: effect of infusion time, mode of packaging and preparation on the extraction efficiency of bioactive compounds and on the stability of the beverage

    Directory of Open Access Journals (Sweden)

    Márcia Fernandes Nishiyama

    2010-05-01

    Full Text Available Os estudos do chá verde brasileiro (Camellia sinensis var assamica ainda são escassos quando comparados aos realizados com chás verdes produzidos em outros países. Os objetivos deste trabalho foram avaliar os efeitos do tempo de infusão, forma de acondicionamento da erva (a granel ou em sachês e forma de preparo da bebida na extração dos biativos do chá verde brasileiro e na estabilidade da bebida obtida. Foram avaliados os parâmetros sólidos solúveis e compostos fenólicos extraídos, bem como as propriedades antioxidantes da bebida pelo método DPPH (radicais 2,2-difenil-1-picrilhidrazil. Os dados obtidos evidenciam que o uso da erva a granel sob agitação e tempo de infusão de 5 minutos foi a condição mais propícia para a extração dos bioativos do chá verde. Aumentando-se o volume de preparação da bebida sem alteração da razão erva:água, aumentou-se a eficiência da extração dos bioativos, devido ao fato de que o resfriamento de volumes maiores é mais demorado que o resfriamento de volumes menores. As bebidas obtidas foram estáveis por 24 horas em temperatura ambiente e em geladeira, visto não terem sido detectadas redução das propriedades antioxidantes e variações significativas dos seus principais bioativos epigalocatequina galato, epicatequina, catequina e cafeína.Studies on the Brazilian green tea (Camellia sinensis var assamica are still scarce when compared with the great number of investigations conducted on the green tea produced in other countries. The purposes of the present study were to evaluate the effects of infusion time, mode of packaging (tea in bulk or in tea bags and preparation on the extraction of bioactive compounds from the Brazilian green tea and on the stability of the beverage. The evaluated parameters were: the amounts of soluble solutes and phenolic compounds that were extracted as well as the antioxidant properties of the beverage using the DPPH method (2,2-diphenyl-1

  18. Exploration of material removal rate of srf elliptical cavities as a function of media type and cavity shape on niobium and copper using centrifugal barrel polishing (cbp)

    Energy Technology Data Exchange (ETDEWEB)

    Palczewski, Ari [JLAB; Ciovati, Gianluigi [JLAB; Li, Yongming [PEKING; Geng, Rongli [JLAB

    2013-09-01

    Centrifugal barrel polishing (cbp) for SRF application is becoming more wide spread as the technique for cavity surface preparation. CBP is now being used in some form at SRF laboratories around the world including in the US, Europe and Asia. Before the process can become as mature as wet chemistry like eletro-polishing (EP) and buffered chemical polishing (BCP) there are many questions which remain unanswered. One of these topics includes the uniformity of removal as a function of cavity shape and material type. In this presentation we show CBP removal rates for various media types on 1.3 GHz TESLA and 1.5 GHz CEBAF large/fine grain niobium cavities, and 1.3GHz low surface field copper cavity. The data will also include calculated RF frequency shift modeling non-uniform removal as a function of cavity position and comparing them with CBP results.

  19. EFEITO TAMANHO NOS FUNDOS DE INVESTIMENTO BRASILEIROS

    Directory of Open Access Journals (Sweden)

    Bruno Milani

    2013-01-01

    Full Text Available A indústria de fundos de investimento desempenha importante papel na captação e alocação de recursos no Brasil. Esse mercado cresceu consideravelmente após a abertura econômica do país, tanto em quantidade de fundos quanto em patrimônio líquido (PL administrado. Este artigo visa averiguar o impacto da oscilação e do tamanho do PL dos fundos de ações brasileiros sobre sua performance, além da influência de sua evolução etária. Foram utilizados dados de frequência diária em um painel de 162 fundos de diferentes tipos de gestão e benchmarks, no período de 2001 a 2009. Diversas regressões foram estimadas, incluindo variáveis que captam a evolução do PL e da idade do fundo e dividindo a amostra em quartis conforme a média de PL dos fundos. As conclusões mostram que os fundos de investimento em ações brasileiros apresentam indícios de efeito tamanho, pois, em geral, fundos com PL maior tendem a apresentar melhor performance. A influência da idade depende da categoria de fundos em análise.

  20. TEM observations of crack tip: cavity interactions

    International Nuclear Information System (INIS)

    Crack tip-cavity interactions have been studied by performing room temperature deformation experiments in a transmission electron microscope on ion-irradiated type 316 stainless steel with small helium containing cavities. Slip dislocations emitted from a crack tip cut, sheared, and thereby elongated cavities without a volume enlargement. As the crack tip approached, a cavity volume enlargement occurred. Instead of the cavities continuing to enlarge until they touch, the walls between the cavities fractured. Fracture surface dimples do not correlate in size or density with these enlarged cavities

  1. First coupled CH power cavity for the FAIR proton injector

    International Nuclear Information System (INIS)

    For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The main acceleration of this room temperature linac will be provided by six CH cavities operated at 325 MHz. Each cavity will be powered by a 2.5 MW Klystron. For the second acceleration unit from 11.5 MeV to 24.2 MeV a 1:2 scaled model has been built. Low level RF measurements have been performed to determine the main parameters and to prove the concept of coupled CH cavities. In 2012, the assembly and tuning of the first power prototype was finished. Until then, the cavity was tested with a preliminary aluminum drift tube structure, which was used for precise frequency and field tuning. In 2013 the final drift tube structure has been welded inside the main tanks and the preparation for copper plating has taken place. This paper reports on the main tuning and commissioning steps towards that novel type of DTL, and it shows the latest results measured on a fully operational and copper plated CH proton cavity.

  2. Normal Conducting RF Cavity for MICE

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; DeMello, A.; Virostek, S.; Zisman, M.; Summers, D.

    2010-05-23

    Normal conducting RF cavities must be used for the cooling section of the international Muon Ionization Cooling Experiment (MICE), currently under construction at Rutherford Appleton Laboratory (RAL) in the UK. Eight 201-MHz cavities are needed for the MICE cooling section; fabrication of the first five cavities is complete. We report the cavity fabrication status including cavity design, fabrication techniques and preliminary low power RF measurements.

  3. Normal Conducting RF Cavity for MICE

    International Nuclear Information System (INIS)

    Normal conducting RF cavities must be used for the cooling section of the international Muon Ionization Cooling Experiment (MICE), currently under construction at Rutherford Appleton Laboratory (RAL) in the UK. Eight 201-MHz cavities are needed for the MICE cooling section; fabrication of the first five cavities is complete. We report the cavity fabrication status including cavity design, fabrication techniques and preliminary low power RF measurements.

  4. Superposition of Fock states via adiabatic passage in a coupled four-level atom-cavity system

    Institute of Scientific and Technical Information of China (English)

    Gong Shang-Qing; Jin Shi-Qi; Li Ru-Xin; Zheng Zhen-Xun; Xu Zhi-Zhan

    2004-01-01

    We have investigated the behaviour of an atom-cavity system via a stimulated Raman adiabatic passage technique in a four-level system, in which two dark states are present. We find, because of the coherent control field, that a superposition of Fock states can be prepared, even when the cavity is initially not in its vacuum state. This method provides a way to generate arbitrary quantum states of a cavity field.

  5. Cavity optomechanics and its applications

    Science.gov (United States)

    Bhattacharya, Mishkatul

    2009-05-01

    Cavity optomechanics is an emerging field at the intersection of quantum optics, atomic physics, nanoscience and gravitational wave interferometry. It involves cavities (with one or more mechanical degrees of freedom) driven by laser radiation. The ensuing optical control of macroscopic mechanical motion may have implications for precision sensing, coherent control of atoms and molecules, and quantum information processing. Due to recent innovations optomechanical physics has been realized in a variety of experimental systems spanning many orders of magnitude in mass and time-scales. In this talk, I will first introduce the basic paradigm of a laser-driven two mirror cavity used for cooling a vibrational mode. A three-mirror configuration recently implemented using a partially transmissive dielectric membrane in a high finesse cavity will then be discussed, and shown to be superior to the two-mirror design in a number of ways. One implication of the three-mirror configuration is the possibility of scaling optomechanical techniques to multiple oscillators. This topic will be explored by analysing the case of two membranes in a cavity where it will be shown that the collective(center-of-mass and breathing) modes of vibration can be cooled independently, analogous to a chain of trapped ions. Finally, future directions for possible applications to the control of atoms and molecules will be indicated briefly.

  6. Development of Side Coupled Cavities

    International Nuclear Information System (INIS)

    Side coupled Cavities are good candidates for proton accelerations in the 90-180 MeV range, as it has been first proposed for the CERN LINAC4 project. A side coupled Linac is made of a lump chain of resonant cavities, alternatively accelerating and coupling. A side coupled cavity has been designed in a CERN-LPSC collaboration to achieve LINAC4 requirements. After RF studies, a complete thermal study has been done, showing that 10-15% is the absolute maximum duty-cycle achievable by such a cavity. Error studies have been developed. They have shown that a tuning ring is mandatory and that a K equals 3% coupling factor is a good choice. A prototype has been built and each cell has been measured and tuned. A simple and accurate method has been used to get both the resonant frequency and the coupling factor, with a movable tuner and a linear fit. A similar method has been used to get the second order coupling factor. A large dispersion is observed on K. This is mainly due to the shape of the coupling apertures, which are very sensitive to mechanical errors. A future and realistic design must be very careful to guarantee a constant aperture (the important parameter is more the dispersion of k than its exact value). Finally, we analyse how to tune the cavity. This has to checked carefully and probably improved or corrected. Results are expected for mid-2008

  7. The ESS spoke cavity cryomodules

    Science.gov (United States)

    Bousson, Sebastien; Darve, Christine; Duthil, Patxi; Elias, Nuno; Molloy, Steve; Reynet, Denis; Thermeau, Jean-Pierre

    2014-01-01

    The European Spallation Source (ESS) is a multi-disciplinary research centre under design and construction in Lund, Sweden. This new facility is funded by a collaboration of 17 European countries and is expected to be up to 30 times brighter than today's leading facilities and neutron sources. The ESS will enable new opportunities for researchers in the fields of life sciences, energy, environmental technology, cultural heritage and fundamental physics. A 5 MW long pulse proton accelerator is used to reach this goal. The pulsed length is 2.86 ms, the repetition frequency is 14 Hz (4 % duty cycle), and the beam current is 62.5 mA. It is composed of one string of spoke cavity cryomodule and two strings of elliptical cavity cryomodules. This paper introduces the thermo-mechanical design and expected operation of the ESS spoke cavity cryomodules. These cryomodules contain two double spoke bulk Niobium cavities operating at 2 K and at a frequency of 352.21 MHz. The superconducting section of the Spoke Linac accelerates the beam from 90 MeV to 220 MeV. A Spoke Cavity Cryomodule Technology Demonstrator will be built and tested in order to validate the ESS series production.

  8. The ESS elliptical cavity cryomodules

    Science.gov (United States)

    Darve, Christine; Bosland, Pierre; Devanz, Guillaume; Olivier, Gilles; Renard, Bertrand; Thermeau, Jean-Pierre

    2014-01-01

    The European Spallation Source (ESS) is a multi-disciplinary research centre under design and construction in Lund, Sweden. This new facility is funded by a collaboration of 17 European countries and is expected to be up to 30 times brighter than today's leading facilities and neutron sources. The ESS will enable new opportunities for researchers in the fields of life sciences, energy, environmental technology, cultural heritage and fundamental physics. A 5 MW long pulse proton accelerator is used to reach this goal. The pulsed length is 2.86 ms, the repetition frequency is 14 Hz (4 % duty cycle), and the beam current is 62.5 mA. The superconducting section of the Linac accelerates the beam from 80 MeV to 2.0 GeV. It is composed of one string of spoke cavity cryomodule and two strings of elliptical cavity cryomodules. These cryomodules contain four elliptical Niobium cavities operating at 2 K and at a frequency of 704.42 MHz. This paper introduces the thermo-mechanical design, the prototyping and the expected operation of the ESS elliptical cavity cryomodules. An Elliptical Cavity Cryomodule Technology Demonstrator (ECCTD) will be built and tested in order to validate the ESS series production.

  9. A SURVEY OF CORONAL CAVITY DENSITY PROFILES

    International Nuclear Information System (INIS)

    Coronal cavities are common features of the solar corona that appear as darkened regions at the base of coronal helmet streamers in coronagraph images. Their darkened appearance indicates that they are regions of lowered density embedded within the comparatively higher density helmet streamer. Despite interfering projection effects of the surrounding helmet streamer (which we refer to as the cavity rim), Fuller et al. have shown that under certain conditions it is possible to use a Van de Hulst inversion of white-light polarized brightness (pB) data to calculate the electron density of both the cavity and cavity rim plasma. In this article, we apply minor modifications to the methods of Fuller et al. in order to improve the accuracy and versatility of the inversion process, and use the new methods to calculate density profiles for both the cavity and cavity rim in 24 cavity systems. We also examine trends in cavity morphology and how departures from the model geometry affect our density calculations. The density calculations reveal that in all 24 cases the cavity plasma has a flatter density profile than the plasma of the cavity rim, meaning that the cavity has a larger density depletion at low altitudes than it does at high altitudes. We find that the mean cavity density is over four times greater than that of a coronal hole at an altitude of 1.2 Rsun and that every cavity in the sample is over twice as dense as a coronal hole at this altitude. Furthermore, we find that different cavity systems near solar maximum span a greater range in density at 1.2 Rsun than do cavity systems near solar minimum, with a slight trend toward higher densities for systems nearer to solar maximum. Finally, we found no significant correlation of cavity density properties with cavity height-indeed, cavities show remarkably similar density depletions-except for the two smallest cavities that show significantly greater depletion.

  10. Efeitos colaterais do metilfenidato Side effects of methylphenidate

    OpenAIRE

    Giuseppe Pastura; Paulo Mattos

    2004-01-01

    OBJETIVOS: Revisar os principais efeitos colaterais do metilfenidato, em curto e longo prazos, no tratamento de crianças com Transtorno do Déficit de Atenção (TDAH). FONTES DE DADOS: Revisão de literatura nos últimos doze anos através de pesquisa no Medline e Lilacs. RESULTADOS: Dentre os efeitos colaterais que surgem em curto prazo, prevalecem a redução de apetite, insônia, cefaléia e dor abdominal, sendo a maioria autolimitada, dose-dependente e de média intensidade. Dentre aqueles em longo...

  11. Efeito antidepressivo do óleo de peixe

    OpenAIRE

    Carabelli, Bruno

    2013-01-01

    Resumo: A fisiopatologia da depressão ainda não é completamente conhecida, mas estudos apontam para uma disfunção no sistema serotoninérgico como possível causa. Estudos mostram que a suplementação, em ratos, com Óleo de Peixe (OP) rico em Ácido Docosahexaenóico (DHA) e Ácido Eicosapentaenóico (EPA), durante períodos críticos do desenvolvimento, produz efeito antidepressivo através de um aumento da neurotransmissão serotoninérgica, particularmente no hipocampo. Considerando este efeito, que t...

  12. Phoxonic crystals and cavity optomechanics

    Science.gov (United States)

    Djafari-Rouhani, Bahram; El-Jallal, Said; Pennec, Yan

    2016-05-01

    Phoxonic crystals are dual phononic/photonic crystals exhibiting simultaneously band gaps for both types of excitations. Therefore, they have the ability to confine phonons and photons in the same cavity and in turn allow the enhancement of their interaction. In this paper, we review some of our theoretical works on cavity optomechanical interactions in different types of phoxonic crystals, including two-dimensional, slab, and nanobeam structures. Two mechanisms are behind the phonon-photon interaction, namely the photoelastic and the moving interface effects. Coupling rates of a few MHz are obtained with high-frequency phonons of a few GHz. Finally, we give some preliminary results about the optomechanical interaction when a metallic nanoparticle is introduced into the cavity, giving rise to coupled photon-plasmon modes or, in the case of very small particles, to an enhancement of the electric field at the position of the particle. xml:lang="fr"

  13. Crab cavities for the LHC

    International Nuclear Information System (INIS)

    For the high-luminosity LHC upgrade program (HL-LHC), the installation of crab cavities (CC) is essential to compensate the geometric luminosity loss due to the crossing angle and for luminosity leveling. One of the major challenges is the compatibility with machine protection in the regime of >500 MJ stored beam energy. Especially in a failure case (e.g. a CC quench or sparking in the coupler), the voltage and/or phase of a CC can change significantly with a fast time-constant of the order of a LHC-turn. This can lead to large, global betatron oscillations of the beam. The status of the LHC crab cavity upgrade program is presented and the influence of crab cavities on the beam dynamics is discussed. Necessary countermeasures to limit the impact of CC failures to an acceptable level are specified and operational scenarios that are compatible with machine protection considerations are proposed.

  14. RRR Characteristics for SRF cavities

    Science.gov (United States)

    Jung, Yoochul; Hyun, Myungook; Joung, Mijoung

    2015-10-01

    The first heavy ion accelerator is being constructed by the rare isotope science project (RISP) launched by the Institute of Basic Science (IBS) in South Korea. Four different types of superconducting cavities were designed, and prototypes such as a quarter-wave resonator (QWR), a half-wave resonator (HWR) and a single-spoke resonator (SSR) were fabricated. One of the critical factors determining the performances of superconducting cavities is the residual resistance ratio (RRR). The RRR values essentially represent how pure niobium is and how fast niobium can transmit heat. In general, the RRR degrades during electron beam welding due to impurity incorporation. Thus, it is important to maintain the RRR above a certain value at which a niobium cavity shows target performance. In this study, RRR degradation related with electron beam welding conditions, for example, the welding power, welding speed, and vacuum level, will be discussed.

  15. RRR Characteristics for SRF Cavities

    CERN Document Server

    Jung, Yoochul; Joung, Mijoung

    2015-01-01

    The first heavy ion accelerator is being constructed by the rare isotope science project (RISP) launched by the Institute of Basic Science (IBS) in South Korea. Four different types of superconducting cavities were designed, and prototypes were fabricated such as a quarter wave resonator (QWR), a half wave resonator (HWR) and a single spoke resonator (SSR). One of the critical factors determining performances of the superconducting cavities is a residual resistance ratio (RRR). The RRR values essentially represent how much niobium is pure and how fast niobium can transmit heat as well. In general, the RRR degrades during electron beam welding due to the impurity incorporation. Thus it is important to maintain RRR above a certain value at which a niobium cavity shows target performance. In this study, RRR degradation related with electron beam welding conditions, for example, welding power, welding speed, and vacuum level will be discussed.

  16. Plasma Processing of SRF Cavities for the next Generation Of Particle Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Vuskovic, Leposava

    2015-11-23

    The cost-effective production of high frequency accelerating fields are the foundation for the next generation of particle accelerators. The Ar/Cl2 plasma etching technology holds the promise to yield a major reduction in cavity preparation costs. Plasma-based dry niobium surface treatment provides an excellent opportunity to remove bulk niobium, eliminate surface imperfections, increase cavity quality factor, and bring accelerating fields to higher levels. At the same time, the developed technology will be more environmentally friendly than the hydrogen fluoride-based wet etching technology. Plasma etching of inner surfaces of standard multi-cell SRF cavities is the main goal of this research in order to eliminate contaminants, including niobium oxides, in the penetration depth region. Successful plasma processing of multi-cell cavities will establish this method as a viable technique in the quest for more efficient components of next generation particle accelerators. In this project the single-cell pill box cavity plasma etching system is developed and etching conditions are determined. An actual single cell SRF cavity (1497 MHz) is plasma etched based on the pill box cavity results. The first RF test of this plasma etched cavity at cryogenic temperature is obtained. The system can also be used for other surface modifications, including tailoring niobium surface properties, surface passivation or nitriding for better performance of SRF cavities. The results of this plasma processing technology may be applied to most of the current SRF cavity fabrication projects. In the course of this project it has been demonstrated that a capacitively coupled radio-frequency discharge can be successfully used for etching curved niobium surfaces, in particular the inner walls of SRF cavities. The results could also be applicable to the inner or concave surfaces of any 3D structure other than an SRF cavity.

  17. Cavity Solitons in VCSEL Devices

    Directory of Open Access Journals (Sweden)

    S. Barbay

    2011-01-01

    Full Text Available We review advances on the experimental study of cavity solitons in VCSELs in the past decade. We emphasize on the design and fabrication of electrically or optically pumped broad-area VCSELs used for CSs formation and review different experimental configurations. Potential applications of CSs in the field of photonics are discussed, in particular the use of CSs for all-optical processing of information and for VCSELs characterization. Prospects on self-localization studies based on vertical cavity devices involving new physical mechanisms are also given.

  18. Radiography of the abdominal cavity

    International Nuclear Information System (INIS)

    Radiography is a very important part of the diagnostic procedure in many small animal diseases. Technically perfect X-rays are essential for the exact diagnosis. The general appearance of the abdominal cavity should be evaluated at first, e.g. the overall contrast and the definition of the visualized organs. Then particular attention should be paid, if there is any peritoneal effusion or free air in the peritoneal cavity. Subsequently each radiographically visible organ has to be evaluated for its position, size, shape and radiographic density

  19. Protein dynamics: hydration and cavities

    Directory of Open Access Journals (Sweden)

    K. Heremans

    2005-08-01

    Full Text Available The temperature-pressure behavior of proteins seems to be unique among the biological macromolecules. Thermodynamic as well as kinetic data show the typical elliptical stability diagram. This may be extended by assuming that the unfolded state gives rise to volume and enthalpy-driven liquid-liquid transitions. A molecular interpretation follows from the temperature and the pressure dependence of the hydration and cavities. We suggest that positron annihilation spectroscopy can provide additional quantitative evidence for the contributions of cavities to the dynamics of proteins. Only mature amyloid fibrils that form from unfolded proteins are very resistant to pressure treatment.

  20. Nanobeam Cavities for Reconfigurable Photonics

    OpenAIRE

    Deotare, Parag

    2012-01-01

    We investigate the design, fabrication, and experimental characterization of high quality factor photonic crystal nanobeam cavities, with theoretical quality factors of \\(1.4 × 10^7\\) in silicon, operating at ~1550 nm. By detecting the cross-polarized resonantly scattered light from a normally incident laser beam, we measure a quality factor of nearly \\(7.5 × 10^5\\). We show on-chip integration of the cavities using waveguides and an inverse taper geometry based mode size converters, and also...

  1. Synchronization in an optomechanical cavity.

    Science.gov (United States)

    Shlomi, Keren; Yuvaraj, D; Baskin, Ilya; Suchoi, Oren; Winik, Roni; Buks, Eyal

    2015-03-01

    We study self-excited oscillations (SEO) in an on-fiber optomechanical cavity. Synchronization is observed when the optical power that is injected into the cavity is periodically modulated. A theoretical analysis based on the Fokker-Planck equation evaluates the expected phase space distribution (PSD) of the self-oscillating mechanical resonator. A tomography technique is employed for extracting PSD from the measured reflected optical power. Time-resolved state tomography measurements are performed to study phase diffusion and phase locking of the SEO. The detuning region inside which synchronization occurs is experimentally determined and the results are compared with the theoretical prediction. PMID:25871175

  2. Sterility of the uterine cavity

    DEFF Research Database (Denmark)

    Møller, Birger R.; Kristiansen, Frank V.; Thorsen, Poul;

    1995-01-01

    In a prospective open study the sterility of the uterine cavity was evaluated in 99 women admitted for hysterectomy. The indications for hysterectomy were in most cases persistent irregular vaginal bleeding and fibromyomas of the uterus. Samples for both aerobic and anaerobic bacteria, Chlamydia...... trachomatis, yeasts and viruses were taken preoperatively from the apex of the vagina and cervical os. Immediately after hysterectomy the uterus was opened under sterile conditions and samples obtained from the isthmus and fundus of the uterine cavity for microbiological examination. Wet smears were taken...

  3. Quantum-state input-output relations for absorbing cavities

    International Nuclear Information System (INIS)

    The quantized electromagnetic field inside and outside an absorbing high-Q cavity is studied, with special emphasis on the absorption losses in the coupling mirror and their influence on the outgoing field. Generalized operator input-output relations are derived, which are used to calculate the Wigner function of the outgoing field. To illustrate the theory, the preparation of the outgoing field in a Schroedinger cat-like state is discussed

  4. Multimode Strong Coupling in Superconducting Cavity Piezo-electromechanics

    OpenAIRE

    Han, Xu; Zou, Chang-Ling; Tang, Hong X.

    2016-01-01

    High frequency mechanical resonators subjected to low thermal phonon occupancy are easier to be prepared to the ground state by direct cryogenic cooling. Their extreme stiffness, however, poses a significant challenge for external interrogations. Here we demonstrate a superconducting cavity piezo-electromechanical system in which multiple modes of a bulk acoustic resonator oscillating at $10\\,\\textrm{GHz}$ are coupled to a planar microwave superconducting resonator with a cooperativity exceed...

  5. Effect of respiratory muscle training on pulmonary function in preoperative preparation of tobacco smokers Efeito do treinamento dos músculos respiratórios sobre a função pulmonar no preparo pré-operatório de tabagistas

    Directory of Open Access Journals (Sweden)

    Carrie Chueiri Ramos Galvan

    2007-04-01

    Full Text Available PURPOSE: To evaluate the effect of utilization of a specific training program of respiratory muscles on pulmonary function in tobacco smokers. METHODS: Fifty asymptomatic tobacco smokers with age superior to 30 years were studied, at the moments: A0 - initial evaluation followed by protocol of respiratory exercises; A1 - reevaluation after 10 minutes of protocol application; and A2 - final reevaluation after 2 weeks of training utilizing the same protocol 3 times per week. The evaluation was realized through measures of maximum respiratory pressures (PImax and PEmax, respiratory peak flow (IPF and EPF, maximum voluntary ventilation (MVV, forced vital capacity (FVC and forced expiratory volume at the 1st second (FEV1. RESULTS: There was no improvement from initial to final evaluation in FVC and FEV1. But there were significant increases in the variables IPF, EPF, MVV and PImax at evaluations A1 and A2. The PEmax variable increased only at evaluation A2. CONCLUSION: The application of the protocol of respiratory exercises with and without additional load in tobacco smokers produced immediate improvement in the performance of respiratory muscles, but this gain was more accentuated after 2 weeks of exercise.OBJETIVO: Avaliar o efeito da utilização de um programa de treinamento específico dos músculos respiratórios sobre a função pulmonar em indivíduos tabagistas. MÉTODOS: Foram estudados 50 indivíduos tabagistas assintomáticos com idade superior a 30 anos, nos seguintes momentos: A0 - avaliação inicial seguida do protocolo de exercícios respiratórios; A1 - reavaliação após 10 minutos da aplicação do protocolo; e A2 -reavaliação final após duas semanas de treinamento utilizando o mesmo protocolo três vezes por semana. A avaliação foi realizada através das medidas de pressões respiratórias máximas (PImax. e PEmax., picos de fluxo respiratórios (PFI e PFE, ventilação voluntária máxima (VVM, capacidade vital For

  6. Deep X-ray lithography fabrication of mm Wave cavities at the Advanced Photon Source

    International Nuclear Information System (INIS)

    Millimeter-wave (mmWave) accelerating cavity structures have been manufactured using the deep x-ray lithography (DXRL) technique. These cavity structures have potential applications as parts of linear accelerators, microwave undulatory, and mm-wave amplifiers. The microfabrication process includes manufacturing of precision x-ray masks, exposure of positive resist by x-rays through the mask, resist development, and electroforming of the final microstructure. Prototypes of a 32-cell, 108-GHz constant-impedance cavity and a 66-cell, 94-GHz constant-gradient cavity were fabricated at APS. Using an HP8510C 26-GHz vector network analyzer, rf measurements are being prepared with a frequency up- and down-converter before and after a test cavity structure. Preliminary design parameters for a 91-GHz multi-module klystron along with an overview of the DXRL technology are also discussed

  7. Generation of multi-atom W states via Raman transition in an optical cavity

    International Nuclear Information System (INIS)

    A simple scheme is proposed to generate the W state of N λ-type neutral atoms trapped in an optical cavity via Raman transition. Conditional on no photon leakage from the cavity, the N-qubit W state can be prepared perfectly by turning on a classical coupling field for an appropriate time. Compared with the previous ones, our scheme requires neither individual laser addressing of the atoms, nor demand for controlling N atoms to go through an optical cavity simultaneously with a constant velocity. We investigate the influence of cavity decay using the quantum jump approach and show that the preparation time decreases and the success probability increases with atom number because of a collective enhancement of the coupling. (general)

  8. Correlation measurements of individual microwave photons emitted from a symmetric cavity

    Energy Technology Data Exchange (ETDEWEB)

    Bozyigit, D; Lang, C; Steffen, L; Fink, J M; Eichler, C; Baur, M; Bianchetti, R; Leek, P J; Filipp, S; Wallraff, A [Department of Physics, ETH Zuerich, CH-8093, Zuerich (Switzerland); Da Silva, M P; Blais, A, E-mail: andreas.wallraff@phys.ethz.ch [Departement de Physique, Universite de Sherbrooke, Sherbrooke, Quebec, J1K 2R1 (Canada)

    2011-01-10

    Superconducting circuits have been successfully established as systems to prepare and investigate microwave light fields at the quantum level. In contrast to optical experiments where light is detected using photon counters, microwaves are usually measured with well developed linear amplifiers. This makes measurements of correlation functions - one of the important tools in optics - harder to achieve because they traditionally rely on photon counters and beam splitters. Here, we demonstrate a system where we can prepare on demand single microwave photons in a cavity and detect them at the two outputs of the cavity using linear amplifiers. Together with efficient data processing, this allows us to measure different observables of the cavity photons, including the first-order correlation function. Using these techniques we demonstrate cooling of a thermal background field in the cavity.

  9. Correlation measurements of individual microwave photons emitted from a symmetric cavity

    International Nuclear Information System (INIS)

    Superconducting circuits have been successfully established as systems to prepare and investigate microwave light fields at the quantum level. In contrast to optical experiments where light is detected using photon counters, microwaves are usually measured with well developed linear amplifiers. This makes measurements of correlation functions - one of the important tools in optics - harder to achieve because they traditionally rely on photon counters and beam splitters. Here, we demonstrate a system where we can prepare on demand single microwave photons in a cavity and detect them at the two outputs of the cavity using linear amplifiers. Together with efficient data processing, this allows us to measure different observables of the cavity photons, including the first-order correlation function. Using these techniques we demonstrate cooling of a thermal background field in the cavity.

  10. Biodiesel metílico de Dipteryx lacunifera: preparação, caracterização e efeito de antioxidantes na estabilidade à oxidação Methyl biodiesel from Dipteryx lacunifera: preparation, characterization and effect of antioxidant on the oxidation stability

    OpenAIRE

    Francisca Diana da Silva Araújo; Carla Verônica Rodarte de Moura; Mariana H. Chaves

    2010-01-01

    The objective of this work was to study the potentialities of Dipteryx lacunifera Ducke seeds oil for biodiesel production. The yield in oil was of 46.11 ± 0.37%. Methyl biodiesel was prepared by base catalyzed transesterification yielding 88.13% and percentage conversion of triglycerides to corresponding methyl ester of 89.1%. The addition of the tertiary butylhydroquinone (TBHQ, 50 ppm), butylated hydroxytoluene (BHT, 50 ppm) and cashew nut shell liquid (CNSL, 2000 ppm) antioxidants in the ...

  11. Field emission in RF cavities

    International Nuclear Information System (INIS)

    Electron field emission limits the accelerating gradient in superconducting cavities. It is shown how and why it is an important problem. The phenomenology of field emission is then described, both in DC and RF regimes. Merits of a few plausible 'remedies' to field emission are discussed. (author)

  12. Nasal cavity and frontal sinuses

    International Nuclear Information System (INIS)

    The anatomy, diagnostic principles, and surgical techniques relating to the nasal cavity and frontal sinuses are reviewed. Disorders are considered under headings of infectious, neoplastic, and miscellaneous conditions. For each disease condition, an attempt is made to emphasize particular problems and discuss new developments on treatment. Specific recommendations have been made where possible, along with the expected outcome

  13. Hybrid Vertical-Cavity Laser

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention provides a light source (2) for light circuits on a silicon platform (3). A vertical laser cavity is formed by a gain region (101) arranged between a top mirror (4) and a bottom grating-mirror (12) in a grating region (11) in a silicon layer (10) on a substrate. A waveguide...

  14. Hydrofracture from a growing cavity

    International Nuclear Information System (INIS)

    The Los Alamos KRAK code has been used to calculate fracturing away from the growing cavity formed by a nuclear detonation. In the 55 ms before rebound, the stress in the surrounding rock is decreasing, and conditions for fracture propagation are good. During this interval, hydrofractures driven by the high-temperature, high-pressure gases within the cavity grow readily. Fracture growth slows when the stress increases as the residual hoop is formed during rebound. However, cracks are found to escape through the residual stress field. The effects of initial conditions and zoning on the numerical calculations are discussed, and the roles of the media saturation and roughness are briefly considered. The largest uncertainty in these calculations is the manner in which the effective pressure used in computing crack widths is extended into the cavity region. Because the present calculations have been done using a very conservative scheme, actual fractures should grow even more readily. We conclude that hydrofracture is an important, if not dominant, process in transporting mass and energy out of a cavity formed by a nuclear detonation

  15. Cavity length below chute aerators

    Institute of Scientific and Technical Information of China (English)

    WU JianHua; RUAN ShiPing

    2008-01-01

    It is proved that air entrainment is one of the efficient measures dealing with cavitation control for the release works of hydropower projects. There are many factors to be considered in designing a chute aerator. One of the most important factors concerns the cavity length below the aerator, which has outstanding effects on air entrainment against cavitation damage. It is crucial to determine reasonable emergence angle for the calculation of the cavity length. In the present paper the overall effects of structural and hydraulic parameters on the emergence angle of the flow from the aerator were analyzed. Four improved expressions of the emergence angle with weight coefficient were investigated through experimental data of 68 points observed from 12 aerators of 6 hydropower projects, of both model and prototype, on the basis of error theory. A method to calculate the cavity length below aerators was suggested, which considers overall effects of the above mentioned parameters. Comparison between the method in this paper and the other five methods of calculating the cavity length showed that the present method is much more reliable than the existing methods while the mean error of the method is less than others.

  16. Cavity length below chute aerators

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    It is proved that air entrainment is one of the efficient measures dealing with cavi-tation control for the release works of hydropower projects. There are many factors to be considered in designing a chute aerator. One of the most important factors concerns the cavity length below the aerator,which has outstanding effects on air entrainment against cavitation damage. It is crucial to determine reasonable emergence angle for the calculation of the cavity length. In the present paper the overall effects of structural and hydraulic parameters on the emergence angle of the flow from the aerator were analyzed. Four improved expressions of the emer-gence angle with weight coefficient were investigated through experimental data of 68 points observed from 12 aerators of 6 hydropower projects,of both model and prototype,on the basis of error theory. A method to calculate the cavity length be-low aerators was suggested,which considers overall effects of the above men-tioned parameters. Comparison between the method in this paper and the other five methods of calculating the cavity length showed that the present method is much more reliable than the existing methods while the mean error of the method is less than others.

  17. Large-mode enhancement cavities.

    Science.gov (United States)

    Carstens, Henning; Holzberger, Simon; Kaster, Jan; Weitenberg, Johannes; Pervak, Volodymyr; Apolonski, Alexander; Fill, Ernst; Krausz, Ferenc; Pupeza, Ioachim

    2013-05-01

    In passive enhancement cavities the achievable power level is limited by mirror damage. Here, we address the design of robust optical resonators with large spot sizes on all mirrors, a measure that promises to mitigate this limitation by decreasing both the intensity and the thermal gradient on the mirror surfaces. We introduce a misalignment sensitivity metric to evaluate the robustness of resonator designs. We identify the standard bow-tie resonator operated close to the inner stability edge as the most robust large-mode cavity and implement this cavity with two spherical mirrors with 600 mm radius of curvature, two plane mirrors and a round trip length of 1.2 m, demonstrating a stable power enhancement of near-infrared laser light by a factor of 2000. Beam radii of 5.7 mm × 2.6 mm (sagittal × tangential 1/e(2) intensity radius) on all mirrors are obtained. We propose a simple all-reflective ellipticity compensation scheme. This will enable a significant increase of the attainable power and intensity levels in enhancement cavities. PMID:23670017

  18. A 200 MHz prebunching cavity

    CERN Multimedia

    1977-01-01

    This cavity was installed in the PS ring and proved very efficient in providing a modulation on the PS beam before it is injected into the SPS machine. Moreover it allowed longitudinal instabilities studies at high intensities. Roberto Cappi stands on the left.

  19. Nanobeam cavities for Reconfigurable Photonics

    Science.gov (United States)

    Deotare, Parag B.

    We investigate the design, fabrication, and experimental characterization of high quality factor photonic crystal nanobeam cavities, with theoretical quality factors of 1.4 x 107 in silicon, operating at ˜ 1550 nm. By detecting the cross-polarized resonantly scattered light from a normally incident laser beam, we measure a quality factor of nearly 7.5 x 105. We show on-chip integration of the cavities using waveguides and an inverse taper geometry based mode size converters, and also demonstrate tuning of the optical resonance using thermo-optic effect. We also study coupled cavities and show that the single nanobeam cavity modes are coupled into even and odd superposition modes. Using electrostatic force and taking advantage of the highly dispersive nature of the even mode to the nanobeam separation, we demonstrate dynamically reconfigurable optical filters tunable continuously and reversibly over a 9.5 nm wavelength range. The electrostatic force, obtained by applying bias voltages directly to the nanobeams, is used to control the spacing between the nanobeams, which in turn results in tuning of the cavity resonance. The observed tuning trends were confirmed through simulations that modeled the electrostatic actuation as well as the optical resonances in our reconfigurable geometries. Finally we demonstrate reconfiguration of coupled cavities by using optical gradient force induced mechanical actuation. Propagating waveguide modes that exist over wide wavelength range are used to actuate the structures and in that way control the resonance of a localized cavity mode. Using this all-optical approach, more than 18 linewidths of tuning range is demonstrated. Using an on-chip temperature self-referencing method that we developed, we determined that 20% of the total tuning was due to optomechanical reconfiguration and the rest due to thermo-optic effects. By operating the device at frequencies higher than the thermal cut-off, we show high speed operation dominated by

  20. Generation of four-particle GHZ states in bimodal cavity QED

    Institute of Scientific and Technical Information of China (English)

    Yang Zhen-Biao

    2007-01-01

    We propose a scheme for preparing four-particle Greenberger-Horne-Zeilinger states using two identical bimodal cavities, each supports two modes with different frequencies. This scheme is an alternative to another published work[Christopher C Gerry 1996 Phys. Rev. A 53 4591]. Comparisons between them are discussed. The fidelity and the probability of success influenced by cavity decay for the generated states are also considered.

  1. Continuous Pump Assisted Conditional Synthesis of Nonclassical States in a Dispersive Cavity QED

    Institute of Scientific and Technical Information of China (English)

    GUOJian-Hong

    2003-01-01

    The interaction of N identical atoms with both a quantized cavity field and an external classical pumping field with the fields being degenerate in frequency, is studied in the regime where the atoms and fields are highly detuned. This dispersive interaction can be used to generate coherent states for the cavity field. By preparing the injected atoms in a superposition of the bare atomic states, various types of Schroedinger-cat-like states may be generated.

  2. Continuous Pump Assisted Conditional Synthesis of Nonclassical States in a Dispersive Cavity QED

    Institute of Scientific and Technical Information of China (English)

    GUO Jian-Hong

    2003-01-01

    The interaction of N identical atoms with both a quantized cavity field and an external classical pumpingfield with the fields being degenerate in frequency, is studied in the regime where the atoms and fields are highly detuned.This dispersive interaction can be used to generate coherent states for the cavity field. By preparing the injected atomsin a superposition of the bare atomic states, various types of Schrodinger-cat-like states may be generated.

  3. Deep drawing experiences of niobium disk for PEFP SRF cavity prototype

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han Sung; An, Sun; Zhang, Liping; Tang, Yazhe; Li, Ying Min; Kwon, Hyeok Jung; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    A superconducting radio frequency (SRF) cavity with a geometrical beta of 0.42 has been designed to accelerate a proton beam after 100 MeV for an extension of Proton Engineering Frontier Project (PEFP). The designed cavity shape is an elliptical and the resonant frequency is 700 MHz. In order to confirm the RF and mechanical properties of the cavity, two prototypes of copper cavities have been fabricated and tested. Based on the experiences gained with the copper prototypes, two niobium prototypes have been designed. One is two-cell cavity and the other is five cell cavity. The two-cell cavity is for finalizing the niobium cavity production procedure and testing the cavity RF properties at a low temperature and moderate power level. The five-cell cavity is for checking the production quality and testing vertical test system in the future. Both of them are under fabrication. Through the fabrication of the niobium prototype, several issues such as deep drawing, electron beam welding and surface treatment will be addressed. The drawing of the PEPF SRF low beta cavity is shown in Fig. 1. Major parameters for the cavity are like following. - Frequency: 700 MHz - Operating mode: TM010 pi mode - Cavity type: Elliptical - Geometrical beta: 0.42 - Number of cells: 5 per cavity - Accelerating gradient: 8 MV/m - Epeak/Eacc: 3.71 - Bpeak/Eacc: 7.47 mT/(MV/m) - R/Q: 102.3 ohm - Epeak: 29.68 MV/m - Field flatness: 1.56 % - Cell to cell coupling: 1.41 % - Geometrical factor: 121.68 ohm - Cavity wall thickness: 4.3 mm - Lorentz force detuning: 0.4 Hz/(MV/m)2 - Stiffening structure: Double ring - Effective length: 0.45 m - External Q of FPC: 8.0E5 {+-}20 % - HOM load: less than 2 W - HOM Qext requirement: less than 3.0E5 At present, all the niobium disk and plates for cavity and NbTi flanges for beam pipe flange are prepared.

  4. The transition from quantum Zeno to anti-Zeno effects for a qubit in a cavity by varying the cavity frequency

    International Nuclear Information System (INIS)

    We propose a strategy to demonstrate the transition from the quantum Zeno effect (QZE) to the anti-Zeno effect (AZE) using a superconducting qubit coupled to a transmission line cavity, by varying the central frequency of the cavity mode. Our results are obtained without the rotating wave approximation (RWA), and the initial state (a dressed state) is easy to prepare. Moreover, we find that in the presence of both qubit's intrinsic bath and the cavity bath, the emergence of the QZE and the AZE behaviors relies not only on the match between the qubit energy-level-spacing and the central frequency of the cavity mode, but also on the coupling strength between the qubit and the cavity mode. -- Highlights: ► We propose how to demonstrate the transition from Zeno effect to anti-Zeno effect. ► Our results are beyond the RWA, and the initial state is easy to prepare. ► The case of both qubit's intrinsic bath and cavity bath coexist is also studied.

  5. Buffer Chemical Polishing and RF Testing of the 56 MHz SRF Cavity

    Energy Technology Data Exchange (ETDEWEB)

    Burrill,A.

    2009-01-01

    The 56 MHz cavity presents a unique challenge in preparing it for RF testing prior to construction of the cryomodule. This challenge arises due to the physical dimensions and subsequent weight of the cavity, and is further complicated by the coaxial geometry, and the need to properly chemically etch and high pressure rinse the entire inner surface prior to RF testing. To the best of my knowledge, this is the largest all niobium SRF cavity to be chemically etched and subsequently tested in a vertical dewar at 4K, and these processes will be the topic of this technical note.

  6. A simple scheme for generating multi-atom GHZ state via cavity QED

    Institute of Scientific and Technical Information of China (English)

    Wang Jun; Yu Long-Bao; Ye Liu

    2007-01-01

    This paper proposes a simple scheme for generating a three-atom GHZ state via cavity quantum electrodynamics (QED). The task can be achieved through the interaction between two EPR states, which can be prepared easily with current technology. In this scheme, the cavity field is only virtually excited during the interaction process, and no quantum information transfer between the atoms and the cavity is required. Thus it greatly prolongs the efficient decoherent time. Moreover, this scheme is also applicable for generating an .N-atom GHZ state.

  7. Mechanical design development of a 476 MHz RF cavity for the PEP-II asymmetric B-factory

    International Nuclear Information System (INIS)

    This report describes the development of a mechanical design for a single-cell 476 MHz room-temperature rf cavity suitable for the PEP-II Asymmetric B-Factory Project at the Stanford Linear Accelerator Center. The work comprised preparation of a preliminary mechanical design of a single-cell 476 MHz rf cavity capable of handling 150 kW dissipation in the cavity walls. The results of extensive two dimensional and three dimensional heat transfer and thermal stress analyses of the cavity structure under high power operating conditions are presented, and a mechanical design and fabrication scheme is proposed. (Author) 9 refs., 38 figs., 4 tabs

  8. Generating photon pulses with an oscillating cavity

    OpenAIRE

    Lambrecht, A.(Laboratoire Kastler-Brossel, CNRS, ENS, Collège de France, UPMC, Campus Jussieu, 75252 Paris, France); Jaekel, M. T.; Reynaud, S

    1998-01-01

    We study the generation of photon pulses from thermal field fluctuations through opto-mechanical coupling to a cavity with an oscillatory motion. Pulses are regularly spaced and become sharp for a high finesse cavity.

  9. Coupled Photonic Crystal Cavity Array Laser

    DEFF Research Database (Denmark)

    Schubert, Martin

    quantum dots are carried out. In agreement with a simple gain model the structures do not show stimulated emission. The spectral splitting due to the coupling between single cavities as well as arrays of cavities is studied theoretically and experimentally. Lasing is observed for photonic crystal cavity......This thesis describes the design, fabrication and characterization of photonic crystal slab lasers. The main focus is on coupled photonic crystal cavity lasers which are examined in great detail. The cavity type which is mainly explored consists of a defect formed by a single missing hole in the...... structures with quantum wells. A detailed Analysis is conducted on single cavities, two coupled cavities and arrays of coupled cavities. The lasing threshold is determined by measuring the photoluminescence intensity depending on the excitation power. Changes in the linewidth and peak position for different...

  10. Operational experience with crab cavities at KEKB

    OpenAIRE

    Funakoshi, Y.; Group, for the KEKB Commissioning

    2014-01-01

    KEKB was in operation from December 1988 to June 2010. The crab cavities were installed at KEKB in February 2007 and worked very stably until the end of KEKB operation. Operational experience of the crab cavities with beams is described.

  11. Stages of Lip and Oral Cavity Cancer

    Science.gov (United States)

    ... common treatment for all stages of lip and oral cavity cancer. Surgery may include the following: Wide local excision : Removal ... cancer may have spread from the lip and oral cavity. Plastic surgery : An operation that restores or improves the appearance ...

  12. What Are Oral Cavity and Oropharyngeal Cancers?

    Science.gov (United States)

    ... Research Get Involved Find Local ACS Learn About Cancer » Oral Cavity and Oropharyngeal Cancer » Detailed Guide » What are ... how cancers start and spread, see What Is Cancer? Oral cavity cancer, or just oral cancer, is cancer ...

  13. Biodiesel metílico de Dipteryx lacunifera: preparação, caracterização e efeito de antioxidantes na estabilidade à oxidação Methyl biodiesel from Dipteryx lacunifera: preparation, characterization and effect of antioxidant on the oxidation stability

    Directory of Open Access Journals (Sweden)

    Francisca Diana da Silva Araújo

    2010-01-01

    Full Text Available The objective of this work was to study the potentialities of Dipteryx lacunifera Ducke seeds oil for biodiesel production. The yield in oil was of 46.11 ± 0.37%. Methyl biodiesel was prepared by base catalyzed transesterification yielding 88.13% and percentage conversion of triglycerides to corresponding methyl ester of 89.1%. The addition of the tertiary butylhydroquinone (TBHQ, 50 ppm, butylated hydroxytoluene (BHT, 50 ppm and cashew nut shell liquid (CNSL, 2000 ppm antioxidants in the biodiesel contributed to the increase of the induction period of 2.97 h for 8.08; 6.06 and 6.02 h, respectively.

  14. Effect of Ca and Li additions on densification and electrical conductivity of 10 mol% gadolinia-doped ceria prepared by the coprecipitation technique; Efeito de adicoes de litio e calcio na densificacao e na condutividade eletrica da ceria-10% mol gadolinia preparada pela tecnica de co-precipitacao

    Energy Technology Data Exchange (ETDEWEB)

    Porfirio, T.C.

    2010-07-01

    Ceria containing rare-earth ceramics are potential candidates for application in intermediate-temperature solid oxide fuel cells. One of the main problems related to these ceramic materials is their relatively low sinterability. In this work, the effects of Ca and Li additions on densification and electrical conductivity of 10 mol% gadolinia-doped ceria was investigated. Ceramic compositions containing 1.5 mol% Ca or Li were prepared by the oxalate coprecipitation technique. Results of sintered density and electrical conductivity were compared to those of ceramic samples obtained by solid state reactions showing the effects of the synthesis method on densification and total electrical conductivity of the sintered materials. (author)

  15. Magnetosheath cavities: case studies using Cluster observations

    OpenAIRE

    Katırcıoğlu, F. T.; Z. Kaymaz; D. G. Sibeck; Dandouras, I.

    2009-01-01

    This paper presents examples of magnetosheath cavities in Cluster spacecraft observations. The cavities are accompanied by high energy particles in the magnetosheath and characterized by depressed magnetic fields and densities. Flow speeds decrease and temperatures increase within the cavities. All magnetosheath parameters show increased variability within the cavities when the energetic particle flux is high. We predict outward motion of the magnetopause boundary in respons...

  16. Parametric resonance in tunable superconducting cavities

    OpenAIRE

    Wustmann, Waltraut; Shumeiko, Vitaly

    2013-01-01

    We develop a theory of parametric resonance in tunable superconducting cavities. The nonlinearity introduced by the superconducting quantum interference device (SQUID) attached to the cavity and damping due to connection of the cavity to a transmission line are taken into consideration. We study in detail the nonlinear classical dynamics of the cavity field below and above the parametric threshold for the degenerate parametric resonance, featuring regimes of multistability and parametric radi...

  17. Prototype storage cavity for LEP accelerating RF

    CERN Multimedia

    1980-01-01

    The principle of an RF storage cavity was demonstrated with this prototype, working at 500 MHz. Ian Wilso seems to hold it in his hands. The storage cavities had 4 portholes, 1 each for: RF feed; tuning; connection to the accelerating cavity; vacuum pump. The final storage cavities were larger, to suit the lower LEP accelerating frequency of 352.2 MHz. See also 8002294, 8006510X, 8109346, 8407619X, and Annual Report 1980, p.115.

  18. Theory and technology for superconducting cavities

    CERN Document Server

    Lengeler, Herbert

    1993-01-01

    The course will address Physicist and Engineers who are newcomers in the field of accelerators and accelerating cavities. The elements of RF-Superconductivity will be presented with special relevance to accelerating cavities. The present ststus of achievable accelerating fields and RF losses will be given and their link to the special technologies for cavity fabrication and surface treatments will be stressed. Cavity auxiliaries like main couplers, higher order mode couplers and frequency tuners will be described.

  19. Cavity QED experiments with ion Coulomb crystals

    DEFF Research Database (Denmark)

    Herskind, Peter Fønss; Dantan, Aurélien; Marler, Joan; Albert, Magnus; Drewsen, Michael

    Cavity QED experimental results demonstrating collective strong coupling between ensembles of atomic ions cooled into Coulomb crystals and optical cavity fields have been achieved. Collective Zeeman coherence times of milliseconds have furthermore been obtained.......Cavity QED experimental results demonstrating collective strong coupling between ensembles of atomic ions cooled into Coulomb crystals and optical cavity fields have been achieved. Collective Zeeman coherence times of milliseconds have furthermore been obtained....

  20. Cavity-water interface is polar

    OpenAIRE

    Friesen, Allan D.; Matyushov, Dmitry V.

    2010-01-01

    We present the results of numerical simulations of the electrostatics and dynamics of water hydration shells surrounding Kihara cavities given by a Lennard-Jones (LJ) layer at the surface of a hard-sphere cavity. The local dielectric response of the hydration layer substantially exceeds that of bulk water, with the magnitude of the dielectric constant peak in the shell increasing with the growing cavity size. The polar shell propagates into bulk water to approximately the cavity radius. The s...

  1. Entanglement generation and quantum information transfer between spatially-separated qubits in different cavities

    International Nuclear Information System (INIS)

    The generation and control of quantum states of spatially-separated qubits distributed in different cavities constitute fundamental tasks in cavity quantum electrodynamics (QED). An interesting question in this context is how to prepare entanglement and realize quantum information transfer between qubits located at different cavities, which are important in large-scale quantum information processing. In this paper, we consider a physical system consisting of two cavities and three qubits. Two of the qubits are placed in two different cavities while the remaining one acts as a coupler, which is used to connect the two cavities. We propose an approach for generating quantum entanglement and implementing quantum information transfer between the two spatially-separated inter-cavity qubits. The quantum operations involved in this proposal are performed by a virtual photon process; thus the cavity decay is greatly suppressed during operations. In addition, to complete these tasks, only one coupler qubit and one operation step are needed. Moreover, there is no need to apply classical pulses, so that the engineering complexity is much reduced and the operation procedure is greatly simplified. Finally, our numerical results illustrate that high-fidelity implementation of this proposal using superconducting phase qubits and one-dimensional transmission line resonators is feasible for current circuit QED implementations. This proposal can also be applied to other types of superconducting qubits, including flux and charge qubits. (paper)

  2. Entanglement generation and quantum information transfer between spatially-separated qubits in different cavities

    Science.gov (United States)

    Yang, Chui-Ping; Su, Qi-Ping; Nori, Franco

    2013-11-01

    The generation and control of quantum states of spatially-separated qubits distributed in different cavities constitute fundamental tasks in cavity quantum electrodynamics (QED). An interesting question in this context is how to prepare entanglement and realize quantum information transfer between qubits located at different cavities, which are important in large-scale quantum information processing. In this paper, we consider a physical system consisting of two cavities and three qubits. Two of the qubits are placed in two different cavities while the remaining one acts as a coupler, which is used to connect the two cavities. We propose an approach for generating quantum entanglement and implementing quantum information transfer between the two spatially-separated inter-cavity qubits. The quantum operations involved in this proposal are performed by a virtual photon process; thus the cavity decay is greatly suppressed during operations. In addition, to complete these tasks, only one coupler qubit and one operation step are needed. Moreover, there is no need to apply classical pulses, so that the engineering complexity is much reduced and the operation procedure is greatly simplified. Finally, our numerical results illustrate that high-fidelity implementation of this proposal using superconducting phase qubits and one-dimensional transmission line resonators is feasible for current circuit QED implementations. This proposal can also be applied to other types of superconducting qubits, including flux and charge qubits.

  3. CLASSIFYING NODULAR LESIONS OF ORAL CAVITY

    OpenAIRE

    Sumit Bhateja

    2013-01-01

    Diagnosis of many lesions of the oral cavity is challenging to most cliniciansbecause of their uncommon prevalence. A number of cystic, osteodystrophic,microbial, tumor and tumor like lesions of the oral cavity are present withcharacteristic exophytic/raised surface; which makes their diagnosis and studysimpler. The present article is attempted at classifying the common nodular lesions ofthe oral cavity.

  4. Nanometer cavities studied by positron annihilation

    International Nuclear Information System (INIS)

    Positronium (Ps) is trapped in cavities in insulating solids, and the lifetime of ortho Ps is determined by the size of the cavity. The information on the properties of the cavities obtained by use of the standard slow positron beam and the 'normal' positron annihilation techniques is compared for several selected cases. (author)

  5. Computer codes for RF cavity design

    International Nuclear Information System (INIS)

    In RF cavity design, numerical modeling is assuming an increasingly important role with the help of sophisticated computer codes and powerful yet affordable computers. A description of the cavity codes in use in the accelerator community has been given previously. The present paper will address the latest developments and discuss their applications to cavity tuning and matching problems. (Author) 8 refs., 10 figs

  6. Computer codes for RF cavity design

    International Nuclear Information System (INIS)

    In RF cavity design, numerical modeling is assuming an increasingly important role with the help of sophisticated computer codes and powerful yet affordable computers. A description of the cavity codes in use in the accelerator community has been given previously. The present paper will address the latest developments and discuss their applications to cavity toning and matching problems

  7. Diffusion stabilizes cavity solitons in bidirectional lasers

    OpenAIRE

    Perez-Arjona, Isabel; Sanchez-Morcillo, Victor; Redondo, Javier; Staliunas, Kestutis; Roldan, Eugenio

    2009-01-01

    We study the influence of field diffusion on the spatial localized structures (cavity solitons) recently predicted in bidirectional lasers. We find twofold positive role of the diffusion: 1) it increases the stability range of the individual (isolated) solitons; 2) it reduces the long-range interaction between the cavity solitons. Latter allows the independent manipulation (writing and erasing) of individual cavity solitons.

  8. Power coupler for the ILC crab cavity

    Energy Technology Data Exchange (ETDEWEB)

    Burt, G.; Dexter, A.; Jenkins, R.; /Lancaster U.; Beard, C.; Goudket, P.; McIntosh, P.A.; /Daresbury; Bellantoni, Leo; /Fermilab

    2007-06-01

    The ILC crab cavity will require the design of an appropriate power coupler. The beam-loading in dipole mode cavities is considerably more variable than accelerating cavities, hence simulations have been performed to establish the required external Q. Simulations of a suitable coupler were then performed and were verified using a normal conducting prototype with variable coupler tips.

  9. EFEITO DE CALDAS SOBRE Corynespora cassiicola

    Directory of Open Access Journals (Sweden)

    Mercia Celoto

    2014-11-01

    Full Text Available The target spot (Corynespora cassiicola, main leaf disease occurred in barbados cherry in the regionof Junqueirópolis, SP, causing severe defoliates of plants. After the cleaning prune, producers apply line sulfhur in plants, for presenting fungicidal, insecticide and acaricide action. The objective of this study was to assess the effect of line sulfhur (75% and 3% - used by producers, bordeaux mixture (75% and „calda Viçosa‟ (75% on Corynespora cassiicola. The syrups were incorporate into potato-dextrose-agar or spore suspension for determination of inhibition of the mycelia growth and spores germination. Leaves barbados cherry, with symptoms of target spot, were treated with syrups. In wet champer, high humidity, was verified that sporulation occured in lesions, however the spores lost viability by presence of syrups in surface. In vitro, line sulfhur to 75% inhibited completely the mycelia growth of the fungus. Line sulfhur, Bordeaux mixture and „calda Viçosa‟ inhibited completely the spores germination. For the reasons, the use of syrups in barbados cherry, can contribute in reduction of souce of inoculum of the pathogen. A mancha alvo (Corynespora cassiicola é a principal doença da cultura da acerola, na região de Junqueirópolis, SP, causando desfolha precoce nas plantas. Após a realização da poda de limpeza anual, os produtores aplicam a calda sulfocálcica nas plantas, por apresentar ação fungicida, inseticida e acaricida. O objetivo deste trabalho foi avaliar em condições in vitro e in vivo o efeito das caldas sulfocálcica, bordalesa e Viçosa sobre Corynespora cassiicola. As caldas foram utilizadas nas seguintes concentrações: calda sulfocálcica (75 e 3% - concentração utilizada por produtores, calda Bordalesa (75% e calda Viçosa (75%. As caldas foram incorporadas em meio de batata-dextrose-ágar ou suspensão de esporos para determinação das inibições do crescimento micelial e da germinação de esporos

  10. State of the art of multicell SC Cavities and Perspectives

    International Nuclear Information System (INIS)

    Superconducting cavity technology has made major progresses in the last decade with the introduction of high purity niobium on an industrial scale and, at the same time, by an improved understanding of the limiting processes in cavity performance, such as multipacting, field emission loading and thermal breakdown. Multicell niobium cavities for Beta=1 particle acceleration, e.g. for the TESLA project, are routinely exceeding gradients of Eacc=20 MV/m after the application of surface preparation techniques such as buffered chemical polishing or electropolishing, high pressure ultrapure water rinsing, UHV heat treatment and clean-room assembly. The successes of the technology for Beta=1 accelerators has triggered a whole set of possible future applications for Beta < 1 particle acceleration such as spallation neutron sources (SNS, ESS), transmutation of nuclear waste (TRASCO, ASH) or rare isotopes (RIA). The most advanced of these projects is SNS now under construction at Oak Ridge National Laboratory. This paper will review the technical solutions adopted to advance SRF technology and their impact on cavity performance, based on the SNS prototyping efforts. Work supported by U.S. DOE contract DE-AC05-84ER40150

  11. Non-reacting flow visualization of supersonic combustor based on cavity and cavity-strut flameholder

    Science.gov (United States)

    Zhao, Yanhui; Liang, Jianhan; Zhao, Yuxin

    2016-04-01

    Nano-particle planer laser scattering and particle image velocimetry technology are employed to observe the flow field of scramjet combustors based on cavity and cavity-strut flameholder. Density field and velocity distribution inside combustors are obtained. Mainstream fluid enters into cavity nearby side wall in experimental observation because side wall shock waves interact with bottom wall boundary layer. Cavity fluid is entrained into mainstream in the middle of combustor meanwhile. Flow past cavity displays obvious three dimensional characteristics in both combustors. But cavity-strut combustor displays asymmetrical flow field because of strut configuration. Mass exchange between mainstream and cavity fluid is evaluated by statistic mass flow rate into cavity. Mass flow rate near side wall is raised to 6.62 times of the value in the middle of cavity combustor while it is 5.1 times in cavity-strut combustor. Further study is needed to injection strategies and realistic flow characteristics on condition of combustion.

  12. Efeitos das condições de preparação e de modificação de superfície de membranas de PEUAPM na separação água/óleo Preparation and surface modification effects of UHMWPE membranes for oil/water separation

    Directory of Open Access Journals (Sweden)

    Laura H. de Carvalho

    2009-01-01

    Full Text Available Baixos custos operacionais, operação relativamente simples, scale-up e manutenção são as principais razões para uso de membrana no processo de separação numa variedade ampla de aplicações, incluindo purificação de efluentes aquosos. Neste trabalho, a influência dos parâmetros de processo na preparação de membranas de PEUAPM simétricas e assimétricas foi investigada. Membranas de PEUAPM tubulares simétricas foram preparadas com pó passante em peneiras de malha # 80 e # 100. As condições de processamento foram: a temperatura (200 e 220 °C; b pressões de compactação (0, 4 e 6 kgf/cm²; e c tempo de sinterização (90 minutos. Membranas assimétricas foram obtidas por deposição de um filme de PEAD sobre a superfície interna das membranas simétricas selecionadas. As Membranas foram caracterizadas por MEV, porosimetria de mercúrio e medidas de fluxo. Nossos dados indicam que, para membranas simétricas, a porosidade e fluxo permeado diminuíram com o aumento da temperatura e pressões de compactação. Redução mais acentuada nestas variáveis foi observada com membranas assimétricas.Low operational costs, relatively simple operation, scale-up and maintenance are the main reason for using membrane separation processes in a wide range of applications. The purpose of this work was to prepare, characterize and investigate the influence of processing parameters (T, P and of an internal surface modification on the performance of UHMWPE membranes. Sinterization was the technique used for membrane preparation. Tubular sintered UHMWPE membranes were prepared with powders sieved through #80 and #100 mesh. Processing conditions were: a temperature (200 and 220 °C; b compacting pressures (0, 4 and 6 kgf/cm²; and c sintering time (90 minutes. Surface modified membranes were obtained by internally impregnating selected UHMWPE membranes with a HDPE dilute solution. Membranes were characterized by SEM, mercury porosimetry water

  13. Status of the ILC Crab Cavity Development

    International Nuclear Information System (INIS)

    The International Linear Collider (ILC) will require two dipole cavities to 'crab' the electron and positron bunches prior to their collision. It is proposed to use two 9 cell SCRF dipole cavities operating at a frequency of 3.9 GHz, with a transverse gradient of 3.8MV/m in order to provide the required transverse kick. Extensive numerical modelling of this cavity and its couplers has been performed. Aluminium prototypes have been manufactured and tested to measure the RF properties of the cavity and couplers. In addition single cell niobium prototypes have been manufactured and tested in a vertical cryostat. The International Collider (ILC) (1) collides bunches of electrons and positrons at a crossing angle of 14 mrad. The angle between these bunches causes a loss in luminosity due to geometric effects (2). The luminosity lost from this geometric effect can be recovered by rotating the bunches into alignment prior to collision. One possible method of rotating the bunches is to use a crab cavity (3). A crab cavity is a transverse defecting cavity, where the phase of the cavity is such that the head and tail of the bunch receive equal and opposite kicks. As the bunches are only 500 nm wide in the horizontal plane, the cavity phase must be strictly controlled to avoid the bunch centre being deflected too much. In order to keep the phase stability within the required limits it is required that the cavity be superconducting to avoid thermal effects in both the cavity and its RF source. At the location of the crab cavity in the ILC there is only 23 cm separation between the centre of the cavity and the extraction line, hence the cavity must be small enough to fit in this space. This, along with the difficulty of making high frequency SRF components, set the frequency of the cavity to 3.9 GHz.

  14. Status of the ILC Crab Cavity Development

    Energy Technology Data Exchange (ETDEWEB)

    Burt, G.; Dexter, A.; /Cockcroft Inst. Accel. Sci. Tech.; Beard, C.; Goudket, P.; McIntosh, P.; /Daresbury; Bellantoni, L.; /Fermilab; Grimm, T.; Li, Z.; Xiao, L.; /SLAC

    2011-10-20

    The International Linear Collider (ILC) will require two dipole cavities to 'crab' the electron and positron bunches prior to their collision. It is proposed to use two 9 cell SCRF dipole cavities operating at a frequency of 3.9 GHz, with a transverse gradient of 3.8MV/m in order to provide the required transverse kick. Extensive numerical modelling of this cavity and its couplers has been performed. Aluminium prototypes have been manufactured and tested to measure the RF properties of the cavity and couplers. In addition single cell niobium prototypes have been manufactured and tested in a vertical cryostat. The International Collider (ILC) [1] collides bunches of electrons and positrons at a crossing angle of 14 mrad. The angle between these bunches causes a loss in luminosity due to geometric effects [2]. The luminosity lost from this geometric effect can be recovered by rotating the bunches into alignment prior to collision. One possible method of rotating the bunches is to use a crab cavity [3]. A crab cavity is a transverse defecting cavity, where the phase of the cavity is such that the head and tail of the bunch receive equal and opposite kicks. As the bunches are only 500 nm wide in the horizontal plane, the cavity phase must be strictly controlled to avoid the bunch centre being deflected too much. In order to keep the phase stability within the required limits it is required that the cavity be superconducting to avoid thermal effects in both the cavity and its RF source. At the location of the crab cavity in the ILC there is only 23 cm separation between the centre of the cavity and the extraction line, hence the cavity must be small enough to fit in this space. This, along with the difficulty of making high frequency SRF components, set the frequency of the cavity to 3.9 GHz.

  15. A micropillar for cavity optomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Aurélien; Neuhaus, Leonhard; Deléglise, Samuel; Briant, Tristan; Cohadon, Pierre-François; Heidmann, Antoine [Laboratoire Kastler Brossel, UPMC-ENS-CNRS, Paris (France); Van Brackel, Emmanuel [Département de Physique, ENS, Paris (France); Chartier, Claude; Ducloux, Olivier; Le Traon, Olivier [Département Mesures Physiques, ONERA, Châtillon (France); Michel, Christophe; Pinard, Laurent; Flaminio, Raffaele [Laboratoire des Matériaux Avancés, IN2P3-CNRS, Lyon (France)

    2014-12-04

    Demonstrating the quantum ground state of a macroscopic mechanical object is a major experimental challenge in physics, at the origin of the rapid emergence of cavity optomechanics. We have developed a new generation of optomechanical devices, based on a microgram quartz micropillar with a very high mechanical quality factor. The structure is used as end mirror in a Fabry-Perot cavity with a high optical finesse, leading to ultra-sensitive interferometric measurement of the resonator displacement. We expect to reach the ground state of this optomechanical resonator by combining cryogenic cooling in a dilution fridge at 30 mK and radiation-pressure cooling. We have already carried out a quantum-limited measurement of the micropillar thermal noise at low temperature.

  16. RF cavity vacuum interlock system

    Science.gov (United States)

    Jordan, K.; Crawford, K.; Bundy, R.; Dylla, H. F.; Heckman, J.; Marshall, J.; Nichols, R.; Osullivan, S.; Preble, J.; Robb, J.

    1992-03-01

    The Continuous Electron Beam Accelerator Facility (CEBAF), a continuous wave (CW) 4 GeV Electron Accelerator is undergoing construction in Newport News, Virginia. When completed in 1994, the accelerator will be the largest installation of radio-frequency superconductivity. Production of cryomodules, the fundamental building block of the machine, has started. A cryomodule consists of four sets of pairs of 1497 MHz, 5 cell niobium cavities contained in separate helium vessels and mounted in a cryostat with appropriate end caps for helium supply and return. Beam vacuum of the cavities, the connecting beam piping, the waveguides, and the cryostat insulating vacuum are crucial to the performance of the machine. The design and initial experience of the vacuum systems for the first 2 1/4 cryomodules that makeup the 45 MEV injector are discussed.

  17. Multi-color Cavity Metrology

    CERN Document Server

    Izumi, Kiwamu; Barr, Bryan; Betzwieser, Joseph; Brooks, Aidan; Dahl, Katrin; Doravari, Suresh; Driggers, Jennifer C; Korth, W Zach; Miao, Haixing; Rollins, Jameson; Vass, Stephen; Yeaton-Massey, David; Adhikari, Rana

    2012-01-01

    Long baseline laser interferometers used for gravitational wave detection have proven to be very complicated to control. In order to have sufficient sensitivity to astrophysical gravitational waves, a set of multiple coupled optical cavities comprising the interferometer must be brought into resonance with the laser field. A set of multi-input, multi-output servos then lock these cavities into place via feedback control. This procedure, known as lock acquisition, has proven to be a vexing problem and has reduced greatly the reliability and duty factor of the past generation of laser interferometers. In this article, we describe a technique for bringing the interferometer from an uncontrolled state into resonance by using harmonically related external fields to provide a deterministic hierarchical control. This technique reduces the effect of the external seismic disturbances by four orders of magnitude and promises to greatly enhance the stability and reliability of the current generation of gravitational wav...

  18. Tuberculosis involving the oral cavity

    OpenAIRE

    Ferguson, Kathleen A.; McCormack, David G

    1993-01-01

    The oral cavity is a rare site for extrapulmonary tuberculosis. A case is reported of a young woman with dysphagia and oral ulceration. The original mucosal biopsy was negative on smear for acid-fast bacilli, and the patient subsequently developed pulmonary symptoms. A diagnosis of Mycobacterium tuberculosis was ultimately made on open lung biopsy. Complete resolution of both mouth lesion and chest involvement occurred with standard antituberculous therapy.

  19. Quantum signalling in cavity QED

    OpenAIRE

    Jonsson, Robert H.; Martin-Martinez, Eduardo; Kempf, Achim

    2013-01-01

    We consider quantum signalling between two-level quantum systems in a cavity, in the pertubative regime of the earliest possible arrival times of the signal. We present two main results: First we find that, perhaps surprisingly, the analogue of amplitude modulated signalling (Alice using her energy eigenstates |g>, |e>, as in the Fermi problem) is generally sub-optimal for communication. Namely, e.g., phase modulated signalling (Alice using, e.g., |+>,|e>-states) overcomes the quantum noise a...

  20. CRAB Cavity in CERN SPS

    OpenAIRE

    Kim, H. J.; Sen, T.

    2012-01-01

    Beam collisions with a crossing angle at the interaction point have been applied in high intensity colliders to reduce the effects of parasitic collisions which induce emittance growth and beam lifetime deterioration. The crossing angle causes the geometrical reduction of the luminosity. Crab cavity can be one of the most promising ways to compensate the crossing angle and to realize effective head-on collisions. Moreover, the crab crossing mitigates the synchro-betatron resonances due to the...

  1. Retention proposal in complex cavities.

    OpenAIRE

    Pedro Alvarez Rodríguez; Eduardo M. Curbeira Hernández; Eduardo Duarte Marrero; Yisell Peláez Rivas; Aracelis Navarro Sánchez

    2003-01-01

    Background: Dental Operatory is the main structure in which Odontology lies. It is not an easy discipline that gives enjoyable results with little effort due to the difficulties that a correct reconstruction of a destroyed dental element offers.The frequency with which pulpar injury occurs while anchoring additional retainers in complex cavities, the technical difficulties the lack of these devices cause and the need to simplify dental procedures lead this study to show the advantages to subs...

  2. Superconducting versus normal conducting cavities

    OpenAIRE

    Podlech, Holger

    2013-01-01

    One of the most important issues of high-power hadron linacs is the choice of technology with respect to superconducting or room-temperature operation. The favour for a specific technology depends on several parameters such as the beam energy, beam current, beam power and duty factor. This contribution gives an overview of the comparison between superconducting and normal conducting cavities. This includes basic radiofrequency (RF) parameters, design criteria, limitations, required RF and plu...

  3. LHC crab-cavity aspects and strategy

    International Nuclear Information System (INIS)

    The 3rd LHC Crab Cavity workshop (LHC-CC09) took place at CERN in October 2009. It reviewed the current status and identified a clear strategy towards a future crab-cavity implementation. Following the success of crab cavities in KEK-B and the strong potential for luminosity gain and leveling, CERN will pursue crab crossing for the LHC upgrade. We present a summary and outcome of the variousworkshop sessions which have led to the LHC crab-cavity strategy, covering topics like layout, cavity design, integration, machine protection, and a potential validation test in the SPS.

  4. Cavity lining in primary teeth.

    Science.gov (United States)

    Chauhan, Ravi

    2016-03-01

    Data sourcesEmbase, Medline, Cochrane Central, Biomed Central and Open Grey databases and bibliographies of identified studies.Study selectionRandomised controlled trials investigating humans with primary caries lesions receiving operative treatment involving caries removal and restoration, with minimum two treatment groups comparing different cavity treatments before restoration (no lining versus lining) were included.Data extraction and synthesisData were extracted independently by two reviewers and study quality assessed using the Cochrane risk of bias tool. Random effect meta-analysis was carried out.ResultsThree studies involving a total of 89 patients were included. All the studies involved primary teeth and were conducted in Brazil. Follow-up periods ranged from 26-53 months. All the studies were considered to be at high risk of bias. Restoring the cavity without lining did not significantly affect the risk of failure. The quality of the evidence was low.ConclusionsCurrent evidence does not support strong recommendations to use or not to use liners after caries removal and before restoring cavities. Our findings are restricted to primary teeth after selective excavation, with only one liner (calcium hydroxide) being used for comparison. PMID:27012571

  5. Novel Geometries for the LHC Crab Cavity

    International Nuclear Information System (INIS)

    In 2017 the LHC is envisioned to increase its luminosity via an upgrade. This upgrade is likely to require a large crossing angle hence a crab cavity is required to align the bunches prior to collision. There are two possible schemes for crab cavity implementation, global and local. In a global crab cavity the crab cavity is far from the IP and the bunch rotates back and forward as it traverses around the accelerator in a closed orbit. For this scheme a two-cell elliptical squashed cavity at 800 MHz is preferred. To avoid any potential beam instabilities all the parasitic modes of the cavities must be damped strongly, however crab cavities have lower order and same order modes in addition to the usual higher order modes and hence a novel damping scheme must be used to provide sufficient damping of these modes. In the local scheme two crab cavities are placed at each side of the IP two start and stop rotation of the bunches. This would require crab cavities much smaller transversely than in the global scheme but the frequency cannot be increased any higher due to the long bunch length of the LHC beam. This will require a novel compact crab cavity design. A superconducting version of a two rod coaxial deflecting cavity as a suitable design is proposed in this paper.

  6. Construction of cavity fabrication facility in KEK

    International Nuclear Information System (INIS)

    In the development of the superconducting cavity for accelerator that is the main composition equipment of international linear collider (ILC), electron beam welding (EBW) becomes an important process on the cavity of which the Nb material is used. The technology of EBW influences the cavity performance that is cavity gradient. Because of EBW in the equator part of cavities and large amount of process is needed for cavity manufacturing process. In KEK we constructs the pilot plant where the superconducting cavity processing technology by EBW. A clean room was completed as of March of 2010, and the main process equipment except EBW and the CP processor were installed in a clean room. As for the EBW machine, it is scheduled to install it in March, 2011. (author)

  7. SPS RF System an Accelerating Cavity

    CERN Multimedia

    1975-01-01

    The picture shows one of the two initially installed cavities. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also gradually increased: by end 1980 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412017X, 7411048X.

  8. Scaled experiments of explosions in cavities

    Science.gov (United States)

    Grun, J.; Cranch, G. A.; Lunsford, R.; Compton, S.; Walton, O. R.; Weaver, J.; Dunlop, W.; Fournier, K. B.

    2016-05-01

    Consequences of an explosion inside an air-filled cavity under the earth's surface are partly duplicated in a laboratory experiment on spatial scales 1000 smaller. The experiment measures shock pressures coupled into a block of material by an explosion inside a gas-filled cavity therein. The explosion is generated by suddenly heating a thin foil that is located near the cavity center with a short laser pulse, which turns the foil into expanding plasma, most of whose energy drives a blast wave in the cavity gas. Variables in the experiment are the cavity radius and explosion energy. Measurements and GEODYN code simulations show that shock pressures measured in the block exhibit a weak dependence on scaled cavity radius up to ˜25 m/kt1/3, above which they decrease rapidly. Possible mechanisms giving rise to this behavior are described. The applicability of this work to validating codes used to simulate full-scale cavity explosions is discussed.

  9. Automated image capture and defects detection by cavity inspection camera

    International Nuclear Information System (INIS)

    The defects as pit and scar make electric/magnetic field enhance and it cause field emission and quench in superconducting cavities. We used inspection camera to find these defects, but the current system which operated by human often mistake file naming and require long acquisition time. This study aims to solve these problems with introduction of cavity driving automation and defect inspection. We used rs232c of serial communication to drive of motor and camera for the automation of the inspection camera, and we used defect inspection software with defects reference images and pattern match software with the OpenCV lib. By the automation, we cut down the acquisition time from 8 hours to 2 hours, however defect inspection software is under preparation. The defect inspection software has a problem of complexity of image back ground. (author)

  10. Multimode Strong Coupling in Superconducting Cavity Piezo-electromechanics

    CERN Document Server

    Han, Xu; Tang, Hong X

    2016-01-01

    High frequency mechanical resonators subjected to low thermal phonon occupancy are easier to be prepared to the ground state by direct cryogenic cooling. Their extreme stiffness, however, poses a significant challenge for external interrogations. Here we demonstrate a superconducting cavity piezo-electromechanical system in which multiple modes of a bulk acoustic resonator oscillating at $10\\,\\textrm{GHz}$ are coupled to a planar microwave superconducting resonator with a cooperativity exceeding $2\\times10^{3}$, deep in the strong coupling regime. By implementation of the non-contact coupling scheme to reduce mechanical dissipation, the system exhibits excellent coherence characterized by a frequency-quality factor product of $7.5\\times10^{15}\\,\\textrm{Hz}$. Interesting dynamics of temporal oscillations of the microwave energy is observed, implying the coherent conversion between phonons and photons. The demonstrated high frequency cavity piezo-electromechanics is compatible with superconducting qubits, repre...

  11. Efeitos pleiotrópicos das estatinas na sepse

    Directory of Open Access Journals (Sweden)

    Silvana Menegoto Nogueira Di Giusto

    2014-04-01

    Full Text Available O objetivo do presente estudo foi revisar os efeitos da terapia com estatinas em pacientes com quadro de sepse. Foi realizada uma busca bibliográfica de artigos na base de dados MEDLINE/PubMed, SciELO e LILACS, no período de publicação delimitado entre 2009 e 2013. Foram incluídos artigos referentes a ensaios clínicos randomizados controlados e estudos de coorte observacionais clínicos. Foram encontrados diversos estudos clínicos e observacionais que investigaram o efeito do uso de estatinas em infecções e em sepse, tanto de uso contínuo pré-hospitalar (com ou sem interrupção durante internação ou com início imediato pós-internação. Alguns estudos descrevem prováveis efeitos positivos e benéficos da terapia com estatinas no quadro de sepse, dentre eles a melhora dos parâmetros inflamatórios e da taxa de mortalidade, porém, esses resultados não se sustentam quando são aplicados métodos estatísticos que levam em conta diferentes variáveis, tais como idade, sexo, comorbidades e gravidade da doença. Até o momento nenhum estudo demonstrou evidências sólidas e significativas quanto à redução de mortalidade e morbidade no quadro séptico associado ao uso de estatinas, indicando que seu efeito benéfico e protetor ainda não foi plenamente delimitado, sendo necessários mais estudos que confirmem os resultados até agora encontrados. 

  12. Efeito residual de temephós em larvas de Aedes aegypti

    OpenAIRE

    Maria de Lourdes G Macoris; Maria Teresa M Andrighetti; Luiz Takaku

    1995-01-01

    Uma das estratégias de controle do Aedes aegypti é o uso do larvicida temephós, cujo efeito residual prolongado permite a programação de tratamentos focais. O objetivo deste estudo é verificar a duração do efeito residual do temephós simulando-se uma situação de campo. Recipientes plásticos com capacidade de um e cinco litros, foram tratados com temephós e seu efeito residual testado a cada trinta dias. Foram observadas diferentes durações do efeito residual, o qual foi maior nos recipientes ...

  13. As diferentes modalidades da crioterapia e os seus efeitos na resistência passiva muscular

    OpenAIRE

    Pereira, Luís Filipe Mendes

    2011-01-01

    Objectivo: A aplicação de crioterapia no tratamento de lesões faz parte do quotidiano dos fisioterapeutas e desportistas. Apesar do seu efeito analgésico e anti-inflamatório ser consensual, existe actualmente pouca informação relativamente ao seu efeito ao nível das propriedades visco-elásticas do tecido muscular. Deste modo, este estudo pretende analisar as diferentes modalidades da crioterapia e os seus efeitos, bem como o efeito da crioterapia na resistência passiva muscular...

  14. Observation and characterization of cavity Rydberg polaritons

    Science.gov (United States)

    Ningyuan, Jia; Georgakopoulos, Alexandros; Ryou, Albert; Schine, Nathan; Sommer, Ariel; Simon, Jonathan

    2016-04-01

    We experimentally demonstrate the emergence of a robust quasiparticle, the cavity Rydberg polariton, when an optical cavity photon hybridizes with a collective Rydberg excitation of a laser-cooled atomic ensemble. Free-space Rydberg polaritons have recently drawn intense interest as tools for quantum information processing and few-body quantum science. Here, we explore the properties of their cavity counterparts in the single-particle sector, observing an enhanced lifetime and slowed dynamics characteristic of cavity dark polaritons. We measure the range of cavity frequencies over which the polaritons persist, corresponding to the spectral width available for polariton quantum dynamics, and the speed limit for quantum information processing. Further, we observe a cavity-induced suppression of inhomogeneous broadening channels and demonstrate the formation of Rydberg polaritons in a multimode cavity. In conjunction with recent demonstrations of Rydberg-induced cavity nonlinearities, our results point the way towards using cavity Rydberg polaritons as a platform for creating high-fidelity photonic quantum materials and, more broadly, indicate that cavity dark polaritons offer enhanced stability and control uniquely suited to optical quantum information processing applications beyond the Rydberg paradigm.

  15. Cavities Formation in Sedimentary Deposits

    Czech Academy of Sciences Publication Activity Database

    Kulaviak, Lukáš; Růžička, Marek; Drahoš, Jiří; Hladil, Jindřich

    Bratislava: Slovak Society of Chemical Engineering , 2008 - (Markoš, J.), s. 241 ISBN 978-80-227-2903-1. [35th International Conference of Slovak Society of Chemical Engineering . Tatranské Matliare (SK), 26.05.2008-30.05.2008] R&D Projects: GA ČR GA104/07/1110; GA ČR GA104/06/1418; GA AV ČR IAAX00130702; GA ČR GP104/06/P287 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z30130516 Keywords : suspension * cavities * stromatactis Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  16. Broadband tuning of optomechanical cavities

    Science.gov (United States)

    Wiederhecker, Gustavo S.; Manipatruni, Sasikanth; Lee, Sunwoo; Lipson, Michal

    2011-01-01

    We demonstrate broadband tuning of an optomechanical microcavity optical resonance by exploring the large optomechanical coupling of a double-wheel microcavity and its uniquely low mechanical stiffness. Using a pump laser with only 13 mW at telecom wavelengths we show tuning of the silicon nitride microcavity resonances over 32 nm. This corresponds to a tuning power efficiency of only 400 $\\mu$W/nm. By choosing a relatively low optical Q resonance ($\\approx$18,000) we prevent the cavity from reaching the regime of regenerative optomechanical oscillations. The static mechanical displacement induced by optical gradient forces is estimated to be as large as 60 nm.

  17. Mass renormalization in cavity QED

    International Nuclear Information System (INIS)

    We show that the presence of a background medium and a boundary surface or surfaces in cavity QED produces no change in the energy shift of a free charged particle due to its coupling to the fluctuating electromagnetic field of the vacuum. This clarifies that the electromagnetic and the observed mass of the charged particle are not affected by the modification of the field of the vacuum. The calculations are nonrelativistic and restricted to the dipole approximation but are otherwise based on the general requirements of causality.

  18. Broadband Tuning of Optomechanical Cavities

    OpenAIRE

    Wiederhecker, Gustavo S.; Manipatruni, Sasikanth; Lee, Sunwoo; Lipson, Michal

    2010-01-01

    We demonstrate broadband tuning of an optomechanical microcavity optical resonance by exploring the large optomechanical coupling of a double-wheel microcavity and its uniquely low mechanical stiffness. Using a pump laser with only 13 mW at telecom wavelengths we show tuning of the silicon nitride microcavity resonances over 32 nm. This corresponds to a tuning power efficiency of only 400 $\\mu$W/nm. By choosing a relatively low optical Q resonance ($\\approx$18,000) we prevent the cavity from ...

  19. Broadband Tuning of Optomechanical Cavities

    CERN Document Server

    Wiederhecker, Gustavo S; Lee, Sunwoo; Lipson, Michal

    2010-01-01

    We demonstrate broadband tuning of an optomechanical microcavity optical resonance by exploring the large optomechanical coupling of a double-wheel microcavity and its uniquely low mechanical stiffness. Using a pump laser with only 13 mW at telecom wavelengths we show tuning of the silicon nitride microcavity resonances over 32 nm. This corresponds to a tuning power efficiency of only 400 $\\mu$W/nm. By choosing a relatively low optical Q resonance ($\\approx$18,000) we prevent the cavity from reaching the regime of regenerative optomechanical oscillations. The static mechanical displacement induced by optical gradient forces is estimated to be as large as 60 nm.

  20. Basketballs as spherical acoustic cavities

    Science.gov (United States)

    Russell, Daniel A.

    2010-06-01

    The sound field resulting from striking a basketball is found to be rich in frequency content, with over 50 partials in the frequency range of 0-12 kHz. The frequencies are found to closely match theoretical expectations for standing wave patterns inside a spherical cavity. Because of the degenerate nature of the mode shapes, explicit identification of the modes is not possible without internal investigation with a microphone probe. A basketball proves to be an interesting application of a boundary value problem involving spherical coordinates.

  1. Photoluminescence microscopy on air-suspended carbon nanotubes coupled to photonic crystal nanobeam cavities

    Science.gov (United States)

    Miura, R.; Imamura, S.; Shimada, T.; Ohta, R.; Iwamoto, S.; Arakawa, Y.; Kato, Y. K.

    2014-03-01

    Because carbon nanotubes are room-temperature telecom-band emitters and can be grown on silicon substrates, they are ideal for coupling to silicon photonic cavities.[2,3 In particular, as-grown air-suspended carbon nanotubes show excellent optical properties, but cavity modes with large fields in the air are needed in order to achieve efficient coupling. Here we investigate individual air-suspended nanotubes coupled to photonic crystal nanobeam cavities. We utilize cavities that confine air-band modes which have large fields in the air. Dielectric mode cavities are also prepared for comparison. We fabricate the devices from silicon-on-insulator substrates by using electron beam lithography and dry etching to form the nanobeam structure. The buried oxide layer is removed by wet etching, and carbon nanotubes are grown onto the cavities by chemical vapor deposition. We perform photoluminescence imaging and excitation spectroscopy to find the positions of the nanotubes and identify their chiralities. For both types of devices, cavity modes with quality factors of ~3000 are observed within the nanotube emission peak. Work supported by SCOPE, KAKENHI, The Telecommunications Advancement Foundation, The Toyota Physical and Chemical Research Institute, Project for Developing Innovation Systems of MEXT, Japan and the Photon Frontier Network Program of MEXT, Japan.

  2. Nitrogen-Doped 9-Cell Cavity Performance in a Test Cryomodule for LCLS-II

    CERN Document Server

    Gonnella, Dan; Furuta, Fumio; Ge, Mingqi; Hall, Daniel; Ho, Vivian; Hoffstaetter, Georg; Liepe, Matthias; O'Connell, Tim; Posen, Sam; Quigley, Peter; Sears, James; Veshcherevich, Vadim; Grassellino, Anna; Romanenko, Alexander; Sergatskov, Dmitri

    2014-01-01

    The superconducting RF linac for LCLS-II calls for 1.3 GHz 9-cell cavities with an average intrinsic quality factor Q0 of 2.7x10^10 at 2 K and 16 MV/m accelerating gradient. Two niobium 9-cell cavities, prepared with nitrogen-doping at Fermilab, were assembled into the Cornell Horizontal Test Cryomodule (HTC) to test cavity performance in a cryomodule that is very similar to a full LCLS-II cryomodule. The cavities met LCLS-II specifications with an average quench field of 17 MV/m and an average Q0 of 3x10^10. The sensitivity of the cavities' residual resistance to ambient magnetic field was determined to be 0.5 nOhm/mG during fast cool down. In two cool downs, a heater attached to one of the cavity beam tubes was used to induce large horizontal temperature gradients. Here we report on the results of these first tests of nitrogen-doped cavities in cryomodule, which provide critical information for the LCLS-II project.

  3. Preparation of two and four-atom entangled states

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A scheme for preparing two and four-atom entangled states is presented. It is based on atom-cavity-field interactions. Firatly, the cav ity is prepared in the superposition of the number states through the atom under going a two-photon transition, the secondly, the two or four identical two-lev el atoms, which are all initially in their ground states, are sent through the c avity sequentially and can make resonant single-photon transition in the cavity . Then atomic entangled states are created and the cavity is left in the vacuum state.

  4. Considerations relating to the presence of water in the reactor cavity during severe accidents

    International Nuclear Information System (INIS)

    The purpose of this paper is to present some of the factors, both positive and negative, associated with the presence of water in the reactor cavity. The presence of water in the reactor cavity is one of the factors whose influence on the evolution of severe accidents must be determined since, on the one hand, it has an impact on some of the most significant severe accident phenomena and, on the other, it could be an important factor when preparing accident management strategies resulting from containment analyses. In spite of the initial intuitive impression that water in the reactor cavity must always be beneficial, certain phenomena, such as the following must also be taken into account before developing accident management strategies: - Higher production of steam - Possibility of steam explosions - Increased production of H2 due to oxidation of steel components of the melted core ejected from the vessel - More oxidation energy released due to the presence of oxygen in the cavity (Author)

  5. The effect of cavity disinfectants on the sealing ability of dentin bonding system: An in vitro study

    Directory of Open Access Journals (Sweden)

    Sharma Vivek

    2009-01-01

    Full Text Available Aim: This study was conducted to determine the effect of three cavity disinfectants (chlorhexidine gluconate based-Consepsis; benzalkonium chloride-based Tubulicid Red, iodine-potassium iodide/copper-sulphate based Ora-5 on the microleakage of a dentin bonding system, Clearfil SE Bond. Materials and Methods: Class V cavities were prepared on 45 extracted molars. The respective experimentalgroups were treated with cavity disinfectants and Clearfil SE Bond. Preparations without cavity disinfectants served as negative control and those with neither disinfectant nor dentin bonding resin application served as positive controls. After the cavity preparations were restored with resin composite (Clearfil APX, the specimens were subjected to dye penetration. Statistical analysis was performed using ANOVA (Kruskal-Wallis test. Results: Unlike Conspesis and Tubulicid Red, Ora-5 exhibited significantly higher microleakage and adversely affected the sealing ability of Clearfil SE bond. Only Consepsis and Tubulicid Red could be used as cavity disinfectants with Clearfil SE bond, without its sealing abilities being adversely affected. Conclusions: 1 Consepsis and Tubulicid Red can be used as cavity disinfectants with Clearfil SE Bond, without the sealing ability of Clearfil SE bond being affected. 2 Ora-5 is not an appropriate disinfectant to be used with this dentin bonding system, because it alters its sealing ability.

  6. Deterministic cavity quantum electrodynamics with trapped ions

    International Nuclear Information System (INIS)

    We have employed radio-frequency trapping to localize a single 40Ca+-ion in a high-finesse optical cavity. By means of laser Doppler cooling, the position spread of the ion's wavefunction along the cavity axis was reduced to 42 nm, a fraction of the resonance wavelength of ionized calcium (λ = 397 nm). By controlling the position of the ion in the optical field, continuous and completely deterministic coupling of ion and field was realized. The precise three-dimensional location of the ion in the cavity was measured by observing the fluorescent light emitted upon excitation in the cavity field. The single-ion system is ideally suited to implement cavity quantum electrodynamics under cw conditions. To this end we operate the cavity on the D3/2-P1/2 transition of 40Ca+ (λ 866 nm). Applications include the controlled generation of single-photon pulses with high efficiency and two-ion quantum gates

  7. Silicon Integrated Cavity Optomechanical Transducer

    Science.gov (United States)

    Zou, Jie; Miao, Houxun; Michels, Thomas; Liu, Yuxiang; Srinivasan, Kartik; Aksyuk, Vladimir

    2013-03-01

    Cavity optomechanics enables measurements of mechanical motion at the fundamental limits of precision imposed by quantum mechanics. However, the need to align and couple devices to off-chip optical components hinders development, miniaturization and broader application of ultrahigh sensitivity chip-scale optomechanical transducers. Here we demonstrate a fully integrated and optical fiber pigtailed optomechanical transducer with a high Q silicon micro-disk cavity near-field coupled to a nanoscale cantilever. We detect the motion of the cantilever by measuring the resonant frequency shift of the whispering gallery mode of the micro-disk. The sensitivity near the standard quantum limit can be reached with sub-uW optical power. Our on-chip approach combines compactness and stability with great design flexibility: the geometry of the micro-disk and cantilever can be tailored to optimize the mechanical/optical Q factors and tune the mechanical frequency over two orders of magnitudes. Electrical transduction in addition to optical transduction was also demonstrated and both can be used to effectively cool the cantilever. Moreover, cantilevers with sharp tips overhanging the chip edge were fabricated to potentially allow the mechanical cantilever to be coupled to a wide range of off-chip systems, such as spins, DNA, nanostructures and atoms on clean surfaces.

  8. Malignant melanoma of the oral cavity

    OpenAIRE

    M.S. Hashemi Pour

    2006-01-01

    Oral malignant melanoma is a rare disease. The common sites of its occurrence are the palate and gingiva with the maxillary arch being affected 80% of the time. Because of their presence at relatively obscure areas in the oral cavity, most of the malignant melanomas of the oral cavity are diagnosed at a late stage. These lesions are associated with poor prognosis. The dental clinician must therefore carefully examine the head, neck, and oral cavity, and any pigmented lesion that may ex...

  9. Hybrid Microwave-Cavity Heat Engine

    OpenAIRE

    Bergenfeldt, Christian; Samuelsson, Peter; Sothmann, Björn; Flindt, Christian; Büttiker, Markus

    2013-01-01

    We propose and analyze the use of hybrid microwave cavities as quantum heat engines. A possible realization consists of two macroscopically separated quantum dot conductors coupled capacitively to the fundamental mode of a microwave cavity. We demonstrate that an electrical current can be induced in one conductor through cavity-mediated processes by heating up the other conductor. The heat engine can reach Carnot efficiency with optimal conversion of heat to work. When the system delivers the...

  10. Effects of subsurface cavity expansion in clays

    OpenAIRE

    Au, SKA; Yeung, AT; Soga, K; Cheng, YM

    2007-01-01

    Subsurface cavity expansion in clay induced by compaction grouting can generate upward displacement of clay and/or increase in effective stress leading to consolidation, resulting in settlement compensation and/or shear strength enhancement respectively. However, the two potential benefits of subsurface cavity expansion may offset each other. Experiments and numerical simulations on the engineering behaviour of E-grade kaolin induced by subsurface pressure-controlled cavity expansion were con...

  11. Development of a cavity enhanced aerosol albedometer

    OpenAIRE

    Zhao, W.; Xu, X.; Dong, M.; Chen, W.; X. Gu; Hu, C; Huang, Y.; Gao, X; Huang, W.; Zhang, W

    2014-01-01

    We report on the development of a cavity enhanced aerosol single scattering albedometer incorporating incoherent broad-band cavity-enhanced spectroscopy (IBBCEAS) approach and an integrating sphere (IS) for simultaneous in situ measurements of aerosol scattering and extinction coefficients in the exact same sample volume. The cavity enhanced albedometer employed a blue light-emitting diode (LED) based IBBCEAS approach for the measurement of wavelength-resolv...

  12. Status of ERL superconducting spoke cavity development

    International Nuclear Information System (INIS)

    We have launched a 5-year research program to develop superconducting spoke cavity for laser Compton scattered (LCS) photon sources. For realizing a wide use of LCS X-ray and gamma-ray sources in academic and industrial applications, we adopt 325-MHz superconducting spoke cavity to electron beam drivers. In this paper, we present our developing status of cavity shape optimization and fabrication design. (author)

  13. Theory of clustered-cavity gyroklystron

    Science.gov (United States)

    Nusinovich, G. S.; Antonsen, T. M.; Guo, H.; Granatstein, V. L.

    2002-09-01

    An analytical theory of a new device configuration, a clustered-cavity gyroklystron, is developed. The device considered has two clusters of cavities: an input cluster and an output cluster. The results show that, by using a cluster cavity concept, the bandwidth of gyroklystrons can be enlarged significantly without sacrifice of gain or efficiency which may lead to the development of a new type of high power, moderate bandwidth millimeter-wave amplifier. The theory has also been used to analyze the effect of stagger tuning between cavity frequencies within a single cluster, as well as between different clusters on the bandwidth and gain of the device.

  14. Single-mode cavity with HOMs absorber

    International Nuclear Information System (INIS)

    We present a new 500 MHz cavity which has a simple damped structure for the 1.5 GeV high-brilliant VUV ring. The feature of the cavity design is that higher-order modes (HOMs) propagate out from the cavity through the beam duct with a large diameter and are absorbed in resistive parts in the duct. A low power measurement on a prototype model of the cavity was carried out and the Q-values of HOMs were confirmed to strongly reduce. Thus the coupled-bunch instabilities due to HOMs are expected to be sufficiently suppressed. (author)

  15. Design studies of SSC coupled cavity linac

    International Nuclear Information System (INIS)

    The SSC coupled cavity linac (CCL) will be a side coupled structure operating at 1284 MHz to accelerate a nominal 25 mA H- beam from 70 MeV to 600 MeV. The authors present results of both cavity design and beam dynamics studies. Each accelerating cavity is optimized by SUPERFISH; coupled cavity characteristics in the region of low-, mid- and high-energies are checked by MAFIA-3D. MAFIA-3D was also used to design the bridge coupler systems. The beam dynamics and error analysis are simulated by CCLDYN and CCLTRACE. Possible future upgrade of the CCL to 1 GeV is also discussed

  16. Optimization of a lasertron double output cavity

    International Nuclear Information System (INIS)

    Double output cavities have been used experimentally to increase the efficiency of high-power klystrons. We have used particle-in-cell simulations with the 2 + 1/2 dimensional code MASK to optimize the design of double output cavities for the lasertron under development at SLAC. We discuss design considerations for double output cavities (e.g., optimum choice of voltages and phases, efficiency, wall interception, breakdown). We describe how one calculates the cavity impedance matrix from the gap voltages and phases. Some results of the effect of varying voltage, perveance, and pulse are reported

  17. Introductory lecture on waveguides and cavities

    International Nuclear Information System (INIS)

    This lecture has two parts: waveguides and cavities. Basic topics are discussed which can serve as bases for the following lectures. Many of the results obtained in the first part concerning waveguides are applied in the second part in the discussion on cavity properties, since a cavity can be considered as a part of a waveguide, a cavity resonant mode being a superposition of two counter-travelling waves in the waveguide. In deriving most of the mathematical formulas, complex number representation - that is, phasor forms - are used. For the final results, however, real number representations are also provided as much as possible as an aid to a more intuitive understanding. (author)

  18. Mechanical Properties of Ingot Nb Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Ciovati, Gianluigi; Dhakal, Pashupati; Kneisel, Peter; Mammosser, John; Matalevich, Joseph; Rao Myneni, Ganapati

    2014-07-01

    This contribution presents the results of measurements of the resonant frequency and of strain along the contour of a single-cell cavity made of ingot Nb subjected to increasing uniform differential pressure, up to 6 atm. The data were used to infer mechanical properties of this material after cavity fabrication, by comparison with the results from simulation calculations done with ANSYS. The objective is to provide useful information about the mechanical properties of ingot Nb cavities which can be used in the design phase of SRF cavities intended to be built with this material.

  19. Design of the ILC Crab Cavity System

    Energy Technology Data Exchange (ETDEWEB)

    Adolphsen, C.; Beard, C.; Bellantoni, L.; Burt, G.; Carter, R.; Chase, B.; Church, M.; Dexter, A.; Dykes, M.; Edwards, H.; Goudket, P; Jenkins, R.; Jones, R.M.; Kalinin,; Khabiboulline, T.; Ko, K.; Latina, A.; Li, Z.; Ma, L.; McIntosh, P.; Ng, C.; /SLAC /Daresbury /Fermilab /Cockcroft Inst. Accel. Sci. Tech. /CERN

    2007-08-15

    The International Linear Collider (ILC) has a 14 mrad crossing angle in order to aid extraction of spent bunches. As a result of the bunch shape at the interaction point, this crossing angle at the collision causes a large luminosity loss which can be recovered by rotating the bunches prior to collision using a crab cavity. The ILC baseline crab cavity is a 9-cell superconducting dipole cavity operating at a frequency of 3.9 GHz. In this paper the design of the ILC crab cavity and its phase control system, as selected for the RDR in February 2007 is described in fuller detail.

  20. Design of the ILC Crab Cavity System

    International Nuclear Information System (INIS)

    The International Linear Collider (ILC) has a 14 mrad crossing angle in order to aid extraction of spent bunches. As a result of the bunch shape at the interaction point, this crossing angle at the collision causes a large luminosity loss which can be recovered by rotating the bunches prior to collision using a crab cavity. The ILC baseline crab cavity is a 9-cell superconducting dipole cavity operating at a frequency of 3.9 GHz. In this paper the design of the ILC crab cavity and its phase control system, as selected for the RDR in February 2007 is described in fuller detail

  1. Temperature stabilization of optofluidic photonic crystal cavities

    DEFF Research Database (Denmark)

    Kamutsch, Christian; Smith, Cameron L.C.; Graham, Alexandra;

    2009-01-01

    demonstrate a PhC cavity with a quality factor of Q15 000 that exhibits a temperature-independent resonance. Temperature-stable cavities constitute a major building block in the development of a large suite of applications from high-sensitivity sensor systems for chemical and biomedical applications to......We present a principle for the temperature stabilization of photonic crystal (PhC) cavities based on optofluidics. We introduce an analytic method enabling a specific mode of a cavity to be made wavelength insensitive to changes in ambient temperature. Using this analysis, we experimentally...

  2. Optically coupled cavities for wavelength switching

    International Nuclear Information System (INIS)

    An optical bistable device which presents hysteresis behavior is proposed and experimentally demonstrated. The system finds applications in wavelength switching, pulse reshaping and optical bistability. It is based on two optically coupled cavities named master and slave. Each cavity includes a semiconductor optical amplifier (SOA), acting as the gain medium of the laser, and two pair of fiber Bragg gratings (FBG) which define the lasing wavelength (being different in each cavity). Finally, a variable optical coupler (VOC) is employed to couple both cavities. Experimental characterization of the system performance is made analyzing the effects of the coupling coefficient between the two cavities and the driving current in each SOA. The properties of the hysteretic bistable curve and switching can be controlled by adjusting these parameters and the loss in the cavities. By selecting the output wavelength (λ1 or λ2) with an external filter it is possible to choose either the invert or non-invert switched signal. Experiments were developed employing both optical discrete components and a photonic integrated circuit. They show that for 8 m-long cavities the maximum switching frequency is about 500 KHz, and for 4 m-long cavities a minimum rise-time about 21 ns was measured. The switching time can be reduced by shortening the cavity lengths and using photonic integrated circuits.

  3. Engineering topological materials in microwave cavity arrays

    CERN Document Server

    Anderson, Brandon M; Owens, Clai; Schuster, David I; Simon, Jonathan

    2016-01-01

    We present a scalable architecture for the exploration of interacting topological phases of photons in arrays of microwave cavities, using established techniques from cavity and circuit quantum electrodynamics. A time-reversal symmetry breaking (non-reciprocal) flux is induced by coupling the microwave cavities to ferrites, allowing for the production of a variety of topological band structures including the $\\alpha=1/4$ Hofstadter model. Effective photon-photon interactions are included by coupling the cavities to superconducting qubits, and are sufficient to produce a $\

  4. Fabrication of Glass Micro-Cavities for Cavity QED Experiments

    CERN Document Server

    Roy, Arpan

    2011-01-01

    We report a process for fabricating high quality, defect-free spherical mirror templates suitable for developing high finesse optical Fabry-Perot resonators. The process utilizes the controlled reflow of borosilicate glass and differential pressure to produce mirrors with 0.3 nanometer surface roughness. The dimensions of the mirrors are in the 0.5-5mm range making them suitable candidates for integration with on-chip neutral atom and ion experiments where enhanced interaction between atoms and photons are required. Moreover the mirror curvature, dimension and placement is readily controlled and the process can easily provide an array of such mirrors. We show that cavities constructed with these mirror templates are well suited to quantum information applications such as single photon sources and atom-photon entanglement.

  5. Optimization of the output cavity for a three cavity X-band gyroklystron amplifier

    International Nuclear Information System (INIS)

    Experimental results of the Univ. of Maryland three-cavity gyroklystron indicate that interactions past the output cavity have enhanced the tube's efficiency. The tube operated at 10 GHz in the TE01 mode. At beam parameters of 425 kV, 204 A, and α=0.7, the three-cavity gyroklystron produced 27 MW at 32% efficiency with gain of 36 dB and pulse energy of 39 J. Four different three-cavity circuits were studied experimentally. These circuits differed mainly in the geometry of the output cavity. Each of these circuits was found to have two distinct operating regimes, which were controlled by the magnetic guide field taper across the circuit. By observing the effects of perturbing the guide field after the output cavity; and using an electric field probe in the output cavity it is shown that one regime corresponds to a CARM-like interaction after the output cavity

  6. Anatomy and Disorders of the Oral Cavity of Ornamental Fish.

    Science.gov (United States)

    Roberts-Sweeney, Helen E

    2016-09-01

    Ornamental fish represent the largest and most diverse group of exotic animals kept as pets. The specific oral anatomy of each family or selected species has evolved to suit the natural environment, feeding behaviors, food or prey type, and location of the food/prey in the water column. The anatomy can change over the life of the animal, from fry to adult. The oral cavity of fish is susceptible to many problems including infectious and parasitic diseases, trauma, and neoplasia. Diagnosis may involve wet mount preparations of exfoliative cytology from the lesion, histopathology, and bacterial or fungal culture. PMID:27497201

  7. Multipartite entangled states in coupled quantum dots and cavity QED

    International Nuclear Information System (INIS)

    We investigate the generation of multipartite entangled state in a system of N quantum dots embedded in a microcavity and examine the emergence of genuine multipartite entanglement by three different characterizations of entanglement. At certain times of dynamical evolution one can generate multipartite entangled coherent exciton states or multiqubit W states by initially preparing the cavity field in a superposition of coherent states or the Fock state with one photon, respectively. Finally, we study environmental effects on multipartite entanglement generation and find that the decay rate for the entanglement is proportional to the number of excitons

  8. Controlling dipole squeezing of two atoms inside a cavity via manipulating an atom outside the cavity

    Institute of Scientific and Technical Information of China (English)

    Liu Tang-Kun; Wang Ji-Suo; Feng Jian; Zhan Ming-Sheng

    2004-01-01

    Considering that three two-level atoms are initially in the GHZ single state and two of the atoms are simultaneously put into a cavity initially in the coherent state, we investigate the dipole squeezing properties of the two atoms inside the cavity under the condition of resonant interaction. It is shown that dipole squeezing properties of the two atoms inside the cavity are strongly affected by rotation manipulating of the atom outside the cavity.

  9. Investigation of Microscopic Materials Limitations of Superconducting RF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Anlage, Steven [University of Maryland

    2014-07-23

    The high-field performance of SRF cavities is often limited by breakdown events below the intrinsic limiting surface fields of Nb, and there is abundant evidence that these breakdown events are localized in space inside the cavity. Also, there is a lack of detailed understanding of the causal links between surface treatments and ultimate RF performance at low temperatures. An understanding of these links would provide a clear roadmap for improvement of SRF cavity performance, and establish a cause-and-effect ‘RF materials science’ of Nb. We propose two specific microscopic approaches to addressing these issues. First is a spatially-resolved local microwave-microscope probe that operates at SRF frequencies and temperatures to discover the microscopic origins of breakdown, and produce quantitative measurements of RF critical fields of coatings and films. Second, RF Laser Scanning Microscopy (LSM) has allowed visualization of RF current flow and sources of nonlinear RF response in superconducting devices with micro-meter spatial resolution. The LSM will be used in conjunction with surface preparation and characterization techniques to create definitive links between physical and chemical processing steps and ultimate cryogenic microwave performance. We propose to develop RF laser scanning microscopy of small-sample Nb pieces to establish surface-processing / RF performance relations through measurement of RF current distributions on micron-length scales and low temperatures.

  10. Hydrodynamic Drag on Streamlined Projectiles and Cavities

    KAUST Repository

    Jetly, Aditya

    2016-04-19

    The air cavity formation resulting from the water-entry of solid objects has been the subject of extensive research due to its application in various fields such as biology, marine vehicles, sports and oil and gas industries. Recently we demonstrated that at certain conditions following the closing of the air cavity formed by the initial impact of a superhydrophobic sphere on a free water surface a stable streamlined shape air cavity can remain attached to the sphere. The formation of superhydrophobic sphere and attached air cavity reaches a steady state during the free fall. In this thesis we further explore this novel phenomenon to quantify the drag on streamlined shape cavities. The drag on the sphere-cavity formation is then compared with the drag on solid projectile which were designed to have self-similar shape to that of the cavity. The solid projectiles of adjustable weight were produced using 3D printing technique. In a set of experiments on the free fall of projectile we determined the variation of projectiles drag coefficient as a function of the projectiles length to diameter ratio and the projectiles specific weight, covering a range of intermediate Reynolds number, Re ~ 104 – 105 which are characteristic for our streamlined cavity experiments. Parallel free fall experiment with sphere attached streamlined air cavity and projectile of the same shape and effective weight clearly demonstrated the drag reduction effect due to the stress-free boundary condition at cavity liquid interface. The streamlined cavity experiments can be used as the upper bound estimate of the drag reduction by air layers naturally sustained on superhydrophobic surfaces in contact with water. In the final part of the thesis we design an experiment to test the drag reduction capacity of robust superhydrophobic coatings deposited on the surface of various model vessels.

  11. Superconducting cavities developments efforts at RRCAT

    International Nuclear Information System (INIS)

    Superconducting RE cavities are the work-horse for many existing and proposed linear accelerators. Raja Ramanna Centre for Advanced Technology (RRCAT) has initiated a comprehensive R and D program for development of Superconducting RF cavities suitable for high energy accelerator application like SNS and ADS. For the initial phase of technology demonstration several prototype 1.3 GHz single cell-cavities have been developed. The work began with development of prototype single cell cavities in aluminum and copper. This helped in development of cavity manufacturing process, proving various tooling and learning on various mechanical and RF qualification processes. The parts manufacturing was done at RRCAT and Electron beam welding was carried out at Indian industry. These cavities further served during commissioning trials for various cavity processing infrastructure being developed at RRCAT and are also a potential candidate for Niobium thin film deposition R and D. Based on the above experience, few single cell cavities were developed in fine grain niobium. The critical technology of forming and machining of niobium and the intermediate RF qualification were developed at RRCAT. The EB welding of bulk niobium cavities was carried out in collaboration with IUAC, New Delhi at their facility. As a next logical step efforts are now on for development of multicell cavities. The prototype dumbbells and end group made of aluminium, comprising of RF and HOM couplers ports have also been developed, with their LB welding done at Indian industry. In this paper we shall present the development efforts towards manufacturing of 1.3 GHz single cell cavities and their initial processing and qualification. (author)

  12. Scheme for realizing assisted cloning of an unknown two-atom entangled state via cavity QED

    Institute of Scientific and Technical Information of China (English)

    Zhan You-Bang

    2008-01-01

    This paper proposes a scheme where one can realize quantum cloning of an unknown two-atom entangled state with assistance of a state preparer in cavity QED.The first stage of the scheme requires usual teleportation.In the second stage of the scheme,with the assistance of the preparer,the perfect copies of an unknown atomic entangled state can be produced.

  13. The use of thermovision camera to observe physiological and pathological conditions of oral cavity mucous membrane

    Science.gov (United States)

    Dąbrowski, M.; Dulski, R.; Żmuda, S.; Zaborowski, P.; Pogorzelski, C.

    2002-06-01

    This article presents initial results of investigations of the temperature distribution changes in oral cavity mucous membrane. The investigations aimed to prepare a model of temperature changes existing within mucosal membrane in physiological conditions and to compare those changes with those under pathological conditions. Our investigations were carried out using an infrared imaging system. A representative group of patients was tested.

  14. [Estimation of antimicrobial means action efficacy in children oral cavities by pH-test].

    Science.gov (United States)

    Guliamov, S S

    2009-01-01

    Possibility of mixed saliva pH determination in the efficacy of antimicrobial mean action was assessed using fluctuations in hydrogen index (pH following consumption of sweets in teenagers according to Stephan curve). Antimicrobial activity of chlorhexidine-containing preparation Eludrile and Elgidium-tooth paste, as well as furacillin solution in oral cavities of teenagers was estimated. PMID:19365352

  15. The HIE-ISOLDE Superconducting Cavities: Surface Treatment and Niobium Thin Film Coating

    CERN Document Server

    Lanza, G; Ferreira, L M A; Gustafsson, A E; Pasini, M; Trilhe, P; Palmieri, V

    2010-01-01

    CERN has designed and prepared new facilities for the surface treatment and niobium sputter coating of the HIE-ISOLDE superconducting cavities. We describe here the design choices, as well as the results of the first surface treatments and test coatings.

  16. External cavity quantum cascade laser

    International Nuclear Information System (INIS)

    In this paper we review the progress of the development of mid-infrared quantum cascade lasers (QCLs) operated in an external cavity configuration. We concentrate on QCLs based on the bound-to-continuum design, since this design is especially suitable for broadband applications. Since they were first demonstrated, these laser-based tunable sources have improved in performance in terms of output power, duty cycle, operation temperature and tuneability. Nowadays they are an interesting alternative to FTIRs for some applications. They operate at room temperature, feature a high spectral resolution while being small in size. They were successfully used in different absorption spectroscopy techniques. Due to their vast potential for applications in industry, medicine, security and research, these sources enjoy increasing interest within the research community as well as in industry. (topical review)

  17. Cavity Voltage Phase Modulation MD

    CERN Document Server

    Mastoridis, T; Butterworth, A; Molendijk, J; Tuckmantel, J

    2012-01-01

    The LHC RF/LLRF system is currently setup for extremely stable RF voltage to minimize transient beam loading eects. The present scheme cannot be extended beyond nominal beam current since the demanded power would push the klystrons to saturation. For beam currents above nominal (and possibly earlier), the cavity phase modulation by the beam will be not be corrected (transient beam loading), but the strong RF feedback and One-Turn Delay feedback will still be active for loop and beam stability in physics. To achieve this, the voltage set point will be adapted for each bunch. The goal of this MD was to test an iterative algorithm that would adjust the voltage set point to achieve the optimal phase modulation for klystron forward power considerations.

  18. Cavity pressure history of contained nuclear explosions

    International Nuclear Information System (INIS)

    Knowledge of pressure in cavities created by contained nuclear explosions is useful for estimating the possibility of venting radioactive debris to the atmosphere. Measurements of cavity pressure, or temperature, would be helpful in evaluating the correctness of present code predictions of underground explosions. In instrumenting and interpreting such measurements it is necessary to have good theoretical estimates of cavity pressures. In this paper cavity pressure is estimated at the time when cavity growth is complete. Its subsequent decrease due to heat loss from the cavity to the surrounding media is also predicted. The starting pressure (the pressure at the end of cavity growth) is obtained by adiabatic expansion to the final cavity size of the vaporized rock gas sphere created by the explosion. Estimates of cavity size can be obtained by stress propagation computer codes, such as SOC and TENSOR. However, such estimates require considerable time and effort. In this paper, cavity size is estimated using a scheme involving simple hand calculations. The prediction is complicated by uncertainties in the knowledge of silica water system chemistry and a lack of information concerning possible blowoff of wall material during cavity growth. If wall material blows off, it can significantly change the water content in the cavity, compared to the water content in the ambient media. After cavity growth is complete, the pressure will change because of heat loss to the surrounding media. Heat transfer by convection, radiation and conduction is considered, and its effect on the pressure is calculated. Analysis of cavity heat transfer is made difficult by the complex nature of processes which occur at the wall where melting, vaporization and condensation of the gaseous rock can all occur. Furthermore, the melted wall material could be removed by flowing or dripping to the cavity floor. It could also be removed by expansion of the steam contained in the melt (blowoff) and by

  19. Scheme for Implementation of Quantum Game in Cavity QED

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-Chun; CAO Shu-Ai; WU Yue-Qin; FANG Mao-Fa; LI Huai-Fan; ZHENG Xiao-Juan; ZHAO Ren; WANG Xin-Wen; LI Ze-Hua

    2008-01-01

    We propose an experimentally feasible scheme to implement two-player quantum game in cavity quantum electrodynamics (QED). During the process, the cavity is only virtually excited, thus our scheme is insensitive to the cavity field states and cavity decay. The scheme can be realized in the range of current cavity QED techniques.

  20. Scheme for Implementation of Quantum Game in Cavity QED

    International Nuclear Information System (INIS)

    We propose an experimentally feasible scheme to implement two-player quantum game in cavity quantum electrodynamics (QED). During the process, the cavity is only virtually excited, thus our scheme is insensitive to the cavity field states and cavity decay. The scheme can be realized in the range of current cavity QED techniques.

  1. Carcinomas of the nasal cavity

    International Nuclear Information System (INIS)

    Between 1969-1985, 45 patients with carcinomas of the nasal cavity proper received curative treatment. Of these, 30 had squamous cell carcinoma, 1 un-differentiated carcinoma, 9 adenocarcinoma and 5 adenoid cystic carcinoma. 18 Patients were treated with definitive radiotherapy (interstitial brachy-therapy in 5 patients and external beam therapy in 13 patients), 27 received surgery and radiotherapy. Median length of follow-up was 11 years (range 2.8-16.8 years). 36 Patients had no evidence of disease at the last follow-up visit. All 14 patients with carcinoma of nasal septum had the disease controlled. 9/31 Patients with lesions of lateral wall and floor died of the disease, 5 of uncontrolled local disease, 2 of distant metastases, 2 of both. Disease specific survival rates at 5 and 10 years were 83 and 80%, the corresponding overall survival rates were 75 and 60%. Blindness occurred in 4 patients, 2 due to orbital exenteration and 2 to radiation injury to the cornea and optic pathway. Other infrequent side effects were bone necrosis, dental decay, nasal stenosis and septal perforation. This study indicated that prognosis of patients with nasal cavity carcinoma was better than that of patients with maxillary sinus cancer treated during the same era. In addition, the study showed that carcinoma of the nasal septum were smaller than those of lateral wall and floor at diagnosis, so that excellent control could be achieved by definitive radiotherapy; when accessible, interstitial brachytherapy might be the treatment of choice in such patients. (author). 18 refs.; 4 figs.; 2 tabs

  2. Efeito protetor do aleitamento materno contra a obesidade infantil

    Directory of Open Access Journals (Sweden)

    Balaban Geni

    2004-01-01

    Full Text Available OBJETIVO: Apresentar uma revisão da literatura sobre a hipótese de que o aleitamento materno teria um efeito protetor contra a obesidade infantil, a plausibilidade biológica dessa hipótese e os mecanismos potencialmente envolvidos. FONTES DOS DADOS: Informações coletadas a partir de artigos publicados em revistas científicas indexadas, livros e teses de pós-graduação. A maioria dos artigos foi identificada a partir das bases de dados MEDLINE e Scielo, usando as palavras-chave "aleitamento materno", "sobrepeso", "obesidade", "crianças" e "adolescentes". O período pesquisado foi de 1980 a 2002. Outros artigos foram identificados a partir das referências bibliográficas citadas nos primeiros artigos. SÍNTESE DOS DADOS: A maioria dos estudos revisados relatou um efeito protetor do aleitamento materno contra a obesidade infantil; alguns estudos não encontraram associação entre aleitamento materno e obesidade; um estudo, com um pequeno tamanho amostral, relatou maior adiposidade entre as crianças que receberam aleitamento materno. Diferentes definições de exposição e desfecho dificultam a comparação entre os estudos. Imprinting metabólico foi sugerido como um mecanismo potencialmente envolvido para explicar a associação. Aspectos comportamentais também podem estar envolvidos. CONCLUSÃO: O aleitamento materno parece ter um efeito protetor contra a obesidade infantil, porém essa questão merece uma investigação mais aprofundada.

  3. Efeitos colaterais do metilfenidato Side effects of methylphenidate

    Directory of Open Access Journals (Sweden)

    Giuseppe Pastura

    2004-01-01

    Full Text Available OBJETIVOS: Revisar os principais efeitos colaterais do metilfenidato, em curto e longo prazos, no tratamento de crianças com Transtorno do Déficit de Atenção (TDAH. FONTES DE DADOS: Revisão de literatura nos últimos doze anos através de pesquisa no Medline e Lilacs. RESULTADOS: Dentre os efeitos colaterais que surgem em curto prazo, prevalecem a redução de apetite, insônia, cefaléia e dor abdominal, sendo a maioria autolimitada, dose-dependente e de média intensidade. Dentre aqueles em longo prazo, são descritas alterações discretas de pressão arterial e freqüência cardíaca e uma possível discreta diminuição da estatura. O abuso e a dependência ao medicamento são observados muito raramente. CONCLUSÕES: O perfil de efeitos colaterais do metilfenidato é seguro, não parecendo justificar o seu uso constrito no Brasil, ante os benefícios robustos amplamente demonstrados na literatura.OBJECTIVE: To review main short-term and long-term side effects of methylphenidate in the treatment of Attention-Deficit Disorder in children. SOURCE OF DATA: a 12-year review in Medline and Lilacs. RESULTS: Among those side effects showed in the short-term, anorexia, insomnia, headache and abdominal pain are the most common ones, being the majority self-limited, dose-dependent and of medium intensity. Long-term side effects consist of mild blood pressure and heart rate increase and possible light growth suppression effect. Abuse and dependency are very rare. CONCLUSIONS: Methylphenidate side effects profile is safe and does not seem to justify its restricted use in Brazil, considering its solid benefits widely demonstrated in literature.

  4. Cavity Pressure Behaviour in Micro Injection Moulding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.;

    2010-01-01

    as well as with the filling of the cavity by the polymer melt. In this paper, two parameters derived from cavity pressure over time (i.e. pressure work). The influence of four µIM parameters (melt temperature, mould temperature, injection speed, aand packing pressure) on the two pressure...

  5. Spallation neutron source RF cavity bias system

    International Nuclear Information System (INIS)

    The Spallation Neutron Source r.f. cavity bias system is described under the topic headings: bias system, r.f. cavity, cables, d.c. bias power supply, transistor regulator and control system. Calculation of 4 core 300 mm solid aluminium cable inductance, coaxial shunt frequency response and transistor regulator computed frequency response, are discussed in appendices 1-3. (U.K.)

  6. Cavity-enhanced absorption for optical refrigeration

    CERN Document Server

    Seletskiy, Denis V; Sheik-Bahae, Mansoor

    2009-01-01

    A 20-fold increase over the single path optical absorption is demonstrated with a low loss medium placed in a resonant cavity. This has been applied to laser cooling of Yb:ZBLAN glass resulting in 90% absorption of the incident pump light. A coupled-cavity scheme to achieve active optical impedance matching is analyzed.

  7. Large grain cavities from pure niobium ingot

    Science.gov (United States)

    Myneni, Ganapati Rao; Kneisel, Peter; Cameiro, Tadeu

    2012-03-06

    Niobium cavities are fabricated by the drawing and ironing of as cast niobium ingot slices rather than from cold rolled niobium sheet. This method results in the production of niobium cavities having a minimum of grain boundaries at a significantly reduced cost as compared to the production of such structures from cold rolled sheet.

  8. High-current SRF cavity design

    Science.gov (United States)

    Meidlinger, D.; Grimm, T. L.; Hartung, W.

    2006-07-01

    For high current applications, it is desirable for the cavity shape to have a low longitudinal loss factor and to have a high beam-breakup threshold current. This paper briefly describes three different cavities designed for this purpose: a six-cell elliptical cavity for particles traveling at the speed of light, a two-cell elliptical cavity for subluminal particle speeds, and a single cell cavity which uses the TM012 mode for acceleration. SUPERFISH simulations predict the peak fields in both of the elliptical cavities will not exceed the TeSLA values by more than 10% but both will have 28.7% larger apertures. The elliptical designs assume the bunch frequency equals the accelerating mode frequency. The beam pipe radius is chosen so that the cutoff frequency is less than twice that of the accelerating mode. Hence all of the monopole and dipole higher-order modes (HOMs) that can be driven by the beam have low loaded Q values. This simplifies the problem of HOM damping. The TM012 cavity is predicted to have much higher peak fields than a π-mode elliptical cavity, but offers potential advantages from its simplified shape; it is essentially a circular waveguide with curved end plates. This basic shape results in easier fabrication and simplified tuning.

  9. High-current SRF cavity design

    International Nuclear Information System (INIS)

    For high current applications, it is desirable for the cavity shape to have a low longitudinal loss factor and to have a high beam-breakup threshold current. This paper briefly describes three different cavities designed for this purpose: a six-cell elliptical cavity for particles traveling at the speed of light, a two-cell elliptical cavity for subluminal particle speeds, and a single cell cavity which uses the TM012 mode for acceleration. SUPERFISH simulations predict the peak fields in both of the elliptical cavities will not exceed the TeSLA values by more than 10% but both will have 28.7% larger apertures. The elliptical designs assume the bunch frequency equals the accelerating mode frequency. The beam pipe radius is chosen so that the cutoff frequency is less than twice that of the accelerating mode. Hence all of the monopole and dipole higher-order modes (HOMs) that can be driven by the beam have low loaded Q values. This simplifies the problem of HOM damping. The TM012 cavity is predicted to have much higher peak fields than a π-mode elliptical cavity, but offers potential advantages from its simplified shape; it is essentially a circular waveguide with curved end plates. This basic shape results in easier fabrication and simplified tuning

  10. Superconducting accelerating four-cell cavity

    CERN Multimedia

    1980-01-01

    A close view of the four-cell cavity. This was a prototype designed for LEP2 (LEP1 had warm copper cavities as accelerating elements). The first successful tests were made in December 1980 - reaching a Q = 10^6. (see photo 8012650X)

  11. Efeito dos incêndios florestais na qualidade do ar

    OpenAIRE

    Miranda, Ana Isabel

    1998-01-01

    Os incêndios florestais podem ser considerados como um processo de combustão natural em grande escala, que consome diversas espécies vegetais numa área geográfica específica Consequentemente, consistem numa fonte potencial de elevadas quantidades de poluentes para a atmosfera, sendo indispensável conhecer o seu impacto na qualidade do ar. O objectivo principal deste trabalho consiste no estudo do efeito das emissões dos incêndios florestais na qualidade do ar. Para tal, foram d...

  12. O EFEITO CHAMARIZ NAS DECISÕES DE INVESTIMENTO

    Directory of Open Access Journals (Sweden)

    César Augusto Tibúrcio Silva

    2012-03-01

    Full Text Available O estudo das fi nanças comportamentais vem ganhando destaque e sendo objeto de diversos trabalhos acadêmicos. Muitos conceitos tradicionais de economia, sobre o homem econômico, têm sido questionados, ao se considerarem aspectos observados na prática. Principalmente, a partir dos modernos estudos de economia comportamental, aponta-se que o homem se comporta de maneira enviesada e irracional, para tomar suas decisões. É infl uenciado por detalhes que podem levá-lo a fazer escolhas menos vantajosas, relacionadas ao seu dinheiro, e nem mesmo se dar conta disso. O efeito chamariz refere-se à infl uência que um item, a ser escolhido, exerce sobre aqueles que farão uma escolha, inclusive levando- os a tomar uma decisão que, anteriormente, era duvidosa, ou até mesmo a mudar uma escolha anterior. Esse efeito mostra como o homem cria falsas bases de comparação, para simplifi car um ambiente de escolha entre opções. O trabalho faz uma pesquisa sobre uma decisão de investimento, em que há duas situações, com a presença ou não de um chamariz, algo que pode infl uenciar a decisão fi nal dos investidores. Participaram da pesquisa 386 alunos de graduação do curso de Ciências Contábeis, de cinco universidades, do Distrito Federal. Os alunos foram considerados investidores capazes de analisar índices de liquidez e de julgar qual seria a melhor opção para investir. Viu-se que as pessoas se sentem incentivadas a investir em empresas nas quais foi criada uma falsa base de comparação, pela presença do chamariz. Esse efeito é observado com maior intensidade em alguns grupos específi cos de investidores. Sugere-se a elaboração de novas pesquisas na área, com o objetivo de observar esse efeito em outras situações e de divulgar o estudo das fi nanças comportamentais.

  13. Efeito do colesterol na atividade da (Na+/K+) ATPase

    OpenAIRE

    Oliveira, Liliana Patrícia Alves

    2012-01-01

    O alumínio é o metal mais abundante na crosta terrestre sendo a sua exposição cada vez maior nas sociedades industrializadas. Numa sociedade cada vez mais envelhecida onde o número de casos de doenças neurodegenerativas tendem a aumentar, parece importante esclarecer os mecanismos celulares da neurotoxicidade do alumínio de forma a prevenir os seus efeitos. Estudos in vivo e in vitro indicam que a exposição a alumínio inibe a atividade da (Na+/K+)ATPase, proteína responsável...

  14. O Efeito de Pulfrich e a Esclerose Múltipla

    OpenAIRE

    Ferreira, J.; Abegão Pinto, L; D. Amado; Cunha, JP

    2011-01-01

    Introdução: O efeito de Pulfrich é um fenómeno psicofísico em que o movimento lateral/pendular de um objecto num plano bidimensional pode ser interpretado pelo córtex visual como um movimento tridimensional devido à diferença relativa do tempo de latência entre os dois olhos. Objectivo: Determinar se a neuropatia óptica desmielinizante unilateral ou assimétrica origina o fenómeno de Pulfrich. Métodos: Pesquisámos em 22 doentes com o diagnóstico de neuropatia óptica desmielinizante a per...

  15. Optomechanical photon shuttling between photonic cavities

    CERN Document Server

    Li, Huan

    2014-01-01

    Mechanical motion of photonic devices driven by optical forces provides a profound means of coupling between optical fields. The current focus of these optomechanical effects has been on cavity optomechanics systems in which co-localized optical and mechanical modes interact strongly to enable wave-mixing between photons and phonons and backaction cooling of mechanical modes. Alternatively, extended mechanical modes can also induce strong nonlocal effects on propagating optical fields or multiple localized optical modes at distances. Here, we demonstrate a novel multi-cavity optomechanical device: a "photon see-saw", in which torsional optomechanical motion can shuttle photons between two photonic crystal nanocavities. The resonance frequencies of the two cavities, one on each side of the see-saw, are modulated anti-symmetrically by the device's rotation. Pumping photons into one cavity excites optomechanical self-oscillation which strongly modulates the inter-cavity coupling and shuttles photons to the other...

  16. Air flow in a collapsing cavity

    CERN Document Server

    Peters, Ivo R; Lohse, Detlef; van der Meer, Devaraj

    2013-01-01

    We experimentally study the airflow in a collapsing cavity created by the impact of a circular disk on a water surface. We measure the air velocity in the collapsing neck in two ways: Directly, by means of employing particle image velocimetry of smoke injected into the cavity and indirectly, by determining the time rate of change of the volume of the cavity at pinch-off and deducing the air flow in the neck under the assumption that the air is incompressible. We compare our experiments to boundary integral simulations and show that close to the moment of pinch-off, compressibility of the air starts to play a crucial role in the behavior of the cavity. Finally, we measure how the air flow rate at pinch-off depends on the Froude number and explain the observed dependence using a theoretical model of the cavity collapse.

  17. Vertical external cavity surface emitting semiconductor lasers

    CERN Document Server

    Holm, M

    2001-01-01

    Active stabilisation showed a relative locked linewidth of approx 3 kHz. Coarse tuning over 7 nm was achieved using a 3-plate birefingent filter plate while fine-tuning using cavity length change allowed tuning over 250 MHz. Vertical external cavity semiconductor lasers have emerged as an interesting technology based on current vertical cavity semiconductor laser knowledge. High power output into a single transverse mode has attracted companies requiring good fibre coupling for telecommunications systems. The structure comprises of a grown semiconductor Bragg reflector topped with a multiple quantum well gain region. This is then included in an external cavity. This device is then optically pumped to promote laser action. Theoretical modelling of AIGaAs based VECSEL structures was undertaken, showing the effect of device design on laser characteristics. A simple 3-mirror cavity was constructed to assess the static characteristics of the structure. Up to 153 mW of output power was achieved in a single transver...

  18. HOM dampers for KEKB crab cavity

    International Nuclear Information System (INIS)

    KEKB accelerator is a high luminosity electron positron collider with high beam currents. Two crab cavities were installed in the KEKB ring in January 2007 and the crab crossing operation was started. The ferrite HOM dampers of the crab cavity successfully absorbed HOM powers more than 10 kW and enabled the cavity operation with high beam currents. KEKB recently achieved the world record of the luminosity of 21 nb-1s-1. The HOM dampers contributed to stable operations of the crab cavity at high beam currents. We will present HOM dampers for the crab cavity, absorbed HOM powers in the HOM dampers during high beam current operations and an addition of SiC HOM damper for higher beam current operations. (author)

  19. Casimir forces of metallic microstructures into cavities

    Science.gov (United States)

    Kenanakis, George; Soukoulis, Costas M.; Economou, Eleftherios N.

    2015-08-01

    A theoretical estimate of the Casimir force of a metallic structure embedded into a cubic cavity is proposed. We demonstrate that by calculating the eigenmodes of the system we can determine the Casimir force, which can be either attractive or repulsive, by simply changing the geometry of the structures relative to the walls of the cavity. In this analysis, several cases of structures are taken into account, from rectangular slabs to chiral "omega" particles, and the predicted data are consistent with recent literature. We demonstrate that the sidewalls of the studied cavity contribute decisively to the repulsive Casimir force between the system and the nearby top surface of the cavity. Finally, we provide evidence that the medium embedded into the studied cavity (and especially its permittivity) can change the intensity of the Casimir force, while its repulsive nature, once established (owing to favorable geometrical features), remains quite robust.

  20. Statistics of magnetoconductance in ballistic cavities

    International Nuclear Information System (INIS)

    The statistical properties of magnetoconductance in ballistic microcavities are investigated numerically. The distribution of conductance for chaotic cavities is found to follow the renormalized Porter-Thomas distribution suggested by random-matrix theory for the Gaussian ensemble while the conductance distribution of regular cavities in magnetic fields is nonuniversal and shifted towards the maximum value for a given number of open channels. The renormalized Porter-Thomas distribution implies a universal dependence of fluctuation amplitude on the mean conductance for chaotic cavities in the absence of time-reversal symmetry. The fluctuation amplitude for regular cavities is found to be larger than the saturation value of the fluctuation amplitude of chaotic cavities predicted by random-matrix theory. The change of the mean conductance as a function of the external magnetic field is consistent with semiclassical predictions

  1. In Vitro Evaluation of Access Cavity Location Effect on Fracture Resistance of Maxillary Central Endodontically Treated Teeth

    OpenAIRE

    Shirinzad, M.; Z. Khamverdi; S. Ghorbani

    2014-01-01

    Introduction & Objective: Preparation of access cavity to root canal is a critical phase in endo-dontic treatment. The purpose of this study was to evaluate the effect of access cavity loca-tion (labial or palatal) on fracture resistance of endodontically treated maxillary central teeth. Materials & Methods: In this experimental laboratorial study, 84 intact human maxillary central incisors with similar dimensions were selected. The teeth were divided into 4 test groups as follows: Group 1 : ...

  2. Hard dental tissue minimal-invasive preparation using contemporary polymer rotating instruments and laser

    OpenAIRE

    Beloica Miloš; Vulićević Zoran R.; Mandinić Zoran; Radović Ivana; Jovičić Olivera; Carević Momir; Tekić Jasmina

    2014-01-01

    Goal of contemporary dentistry is to decrease the patient’s discomfort during treatment. Dentists aim to achieve maximum with the newly developed dental materials as well as with new cavity preparation techniques in the shortest time span. Since the development of the first constructed borer (drilling machine) for caries removal, the preparation techniques have considerably changed. The progress of dental materials as well as the cavity preparation techniqu...

  3. HIE-ISOLDE cavity production – results from thermal modelling of the cavity during sputtering

    CERN Document Server

    Kupiainen, P

    2013-01-01

    The HIE-ISOLDE project is in the phase of cavity production and optimization. Cavities are made of copper and sputtered niobium. We build an ANSYS model to model thermal distributions and heat flows in the cavity structure. We limited the analysis to handle the cavity during sputtering and investigated the effect of different coating power. The aim was to check how results compare to experimental data and vary boundary conditions to improve the model. With two boundary conditions (fixed room and cavity top temperatures), we observed a power loss due to fixed temperature, as expected. The temperature gradient between the bottom and top cavity did not reach the values of the experimental data. With one boundary condition (fixed temperature on sputtering chamber structure), the expected linear proportionality was observed clearly between the temperatures of the cavity and the power. The temperature gradients were also observed to increase with power. We observed an offset in the data compared to experimental dat...

  4. On the field dependent surface resistance of niobium on copper cavities

    CERN Document Server

    Junginger, Tobias

    2015-01-01

    The surface resistance Rs of superconducting cavities prepared by sputter coating a thin niobium film on a copper substrate increases significantly stronger with the applied RF field compared to cavities of bulk material. A possible cause is that due to the thermal boundary resistance between the copper substrate and the niobium film Rs is enhanced due to global heating of the inner cavity wall. Introducing helium gas in the cavity and measuring its pressure as a function of applied field allowed to conclude that the inner surface of the cavity is heated up by only 60+/-60 mK when Rs increases with Eacc by 100 nOhm. This is more than one order of magnitude less than what one would expect from global heating. Additionally the effect of cooldown speed and low temperature baking have been investigated in the framework of these experiments. It is shown that for current state of the art niobium on copper cavities there is only a detrimental effect of low temperature baking. A fast cooldown results in a lowered Rs.

  5. Jaynes-Cummings Models with trapped surface-state electrons in THz cavities

    CERN Document Server

    Zhang, Miao; Huang, J S; Wei, L F

    2009-01-01

    An electron floating on the liquid Helium is proposed to be trapped (by a micro-electrode set below the liquid Helium) in a high finesse cavity. Two lowest levels of the vertical motion of the electron acts as a two-level "atom", which could resonantly interact with the THz cavity. In the Lamb-Dicke regime, wherein the electron's in-plane activity region is much smaller than the wavelength of the cavity mode, the famous Jaynes-Cummings model (JCM) could be realized. By applying an additional external classical laser beam to the electron, a driven JCM could also be implemented. With such a driven JCM certain quantum states, e.g., coherent states and the Schrodinger cat states, of the THz cavity field could be prepared by one-step evolution. The numerical results show that, for the typical parameters of the cavity and electron on liquid Helium, a strong coupling between the artificial atom and the THz cavity could be obtained.

  6. Development of high pressure rinsing set up for 650 MHz, 5- cell superconducting RF cavity cleaning

    International Nuclear Information System (INIS)

    High pressure rinsing (HPR) is an ultra-cleanliness process for the surface preparation of high field superconducting RF cavities. Any dust particle or chemical residue on the interior of cavity causes field emission. Jets of high pressure (80-100 bar) ultra pure water dislodge surface contaminants that normally resist removal with conventional rinsing procedures, leading to substantial reduction in field emission and better cavity performance. For cleaning of 650 MHz, 5-cell SRF cavities, a high pressure rinsing set up has been developed at RRCAT. The HPR tool has a rotating wand coaxial with the vertically mounted SRF cavity that is moving up and down. Fan style spray nozzles are attached to the end of the rotating wand and the water jets emerging from spray nozzles scan the entire internal surface of the cavity. The set-up was installed in a specially built clean area meeting cleanliness class 100 standards. The ultrapure water with resistivity 2 ≥ 18 MΩ-cm required for rinsing is obtained from a dedicated water purification system installed for this purpose. The paper describes the salient design and constructional details of the high pressure rinsing set up. Characterization of water jet parameters based on the momentum transfer between the water jet and a load cell is also presented. (author)

  7. Prototype superconducting radio-frequency cavity for LEP

    CERN Multimedia

    1985-01-01

    This niobium superconducting cavity was part of the prototype stages for an upgrade to LEP, known as LEP-2. Superconducting cavities would eventually replace the traditional copper cavities and allow beam energies of 100 GeV.

  8. Cluster state quantum computation in coupled cavity arrays

    CERN Document Server

    Angelakis, D G; Angelakis, Dimitris G.; Kay, Alastair

    2007-01-01

    We propose a scheme for cluster state quantum computation in an array of coupled cavities. Each cavity is doped with a single two-level system. The detuning of the atomic level spacing and photonic frequency can be externally controlled and tuned to achieve photon blockade in the array. We show that in such a regime, long-lived light-matter excitations (polaritons) are generated, and the polaritons effectively become two-level systems which interact through an XY Hamiltonian. A protocol is proposed where the cluster state is prepared in four steps using a part of the available physical qubits as gate ``mediators" and the rest as the logical qubits. The long life of the polaritonic qubits and the ability to perform individual addressing in this system allows for both the efficient preparation of the cluster state and the successful completion of the necessary individual measurements at the end. Possible implementations using coupled defects in photonic crystals, toroidal microcavities and superconducting qubit...

  9. Microleakage of three self-etch bonding agents in class 5 composite cavities

    Directory of Open Access Journals (Sweden)

    Saeed Nemati Anaraki

    2016-07-01

    Full Text Available Background and Aims: Microleakage is one of the most common problems in bonding systems, which cause different clinical shortcomings such as post operative sensitivity, marginal discoloration and pulp necrosis that can decrease those using bonding systems. The aim of this study was to compare the microleakage of three self etch bonding agents (generation 6 and 7 in class 5 composite cavities. Materials and Methods: In this experimental study, 30 facial class 5 cavities were prepared in 30 human premolar teeth which were freshly extracted for orthodontic purposes. Cl V cavities were prepared in 2*3*2 mm dimensions. Occlusal margins were in enamel and gingival ones in cementum and randomly divided into 3 groups of 10 each. Then the cavities were treated by clearhil SE Bond (Kuraray, Japan, G Bond (GC, Japan, and Opti Bond Solo Plus (Kerr, USA, according to the manufacturers’ insductions. Then the cavities were filled using Z100 resin composite. The specimens were then immersed in a 50% AgNo solution for 24 hrs. Then, the teeth were cut buccolingually to be evaluated for dye penetration with stereomicroscope. Data were analyzed using Kruskal-Wallis test. Results: This study revealed that Opti bond solo plus had type1 microleakage (dye penetration up to 1/3 of cavity in 80% of specimen, and type 4 microleakage (along axial wall in 10%. Clearfil SE bond had no leakage in 50%, type1 in 40% and type 2 (up to 2/3 of cavity in 10%. But there was no significant difference in the microleakage at the gingival margins between 3 groups (P>0.05. Conclusion: Clearfil SE Bond and G bond could prevent microleakage more effectively than that of Opti Bond Solo Plus on the occlusal margins. However, no difference in the microleakage on the gingival surfaces was found.

  10. Efeito priming entre figuras de partes do corpo

    Directory of Open Access Journals (Sweden)

    Oliveira, Felipe Santos de

    2010-01-01

    Full Text Available Um estímulo visual (letra, palavra ou objeto pode ter um efeito duradouro sobre o processamento de estímulos subsequentes. Neste trabalho, investigamos o efeito priming de figuras de mãos humanas (esquerda/direita, vista palmar/dorsal sobre o Tempo de Reação Manual (TRM em uma tarefa usando as mesmas figuras como estímulo alvo. Os pares de figuras podiam ser iguais ou não, de acordo com parâmetros como lateralidade ou vista. Três experimentos foram realizados (lateralidade, vista e cor. Neles, a figura de uma mão não-informativa era apresentada por 200 ms no centro de uma tela de computador. Após 1000ms, uma segunda mão era apresentada no mesmo local até a resposta, a qual consistia em pressionar o interruptor esquerdo ou o direito dependendo da lateralidade (Exp. I, da vista (Exp. II ou da cor (Exp. III do estímulo alvo. Os resultados mostraram que a apresentação prévia da figura de uma mão influencia o TRM ao segundo estímulo apenas quando a seleção da resposta é baseada em uma característica corporal (lateralidade ou vista.

  11. Cryogenic rf test of the first plasma etched SRF cavity

    OpenAIRE

    Upadhyay, J.; Palczewski, A.; Popović, S.; Valente-Feliciano, A. -M.; Im, D.; Phillips, L; Vušković, L.

    2016-01-01

    Plasma etching has a potential to be an alternative processing technology for superconducting radio frequency (SRF) cavities. An apparatus and a method are developed for plasma etching of the inner surfaces of SRF cavities. To test the effect of the plasma etching on the cavity rf performance, a 1497 MHz single cell SRF cavity is used. The single cell cavity is mechanically polished, buffer chemically etched afterwards and rf tested at cryogenic temperatures for a baseline test. This cavity i...

  12. Present status of superconducting cavity developments

    Energy Technology Data Exchange (ETDEWEB)

    Ouchi, Nobuo; Kusano, Joichi; Hasegawa, Kazuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1997-11-01

    An R and D work of a superconducting (SC) cavity for the high intensity proton linac has begun at JAERI in collaboration with KEK. The RF field calculation and the structural analysis have been made to determine the cavity shape in the proton energy range between 100 and 1500 MeV. The results indicate the feasibility of a SC proton linac. A vertical test stand with clean room, water rinsing system, cavity evacuation pumping system, cryostat and data acquisition system has been installed to demonstrate the cavity performance. A single cell cavity of {beta}=0.5 has been fabricated and tested at the test stand to obtain the Q-value and the maximum surface electric field strength. The measured Q-values have been found to be high enough for our requirement while the field strength was limited to about 75% of the specification by the multipacting. We describe the preliminary design of the SC cavity, the overview of the vertical test stand and experimental results of the single cell cavity. (author)

  13. Present status of superconducting cavity developments

    International Nuclear Information System (INIS)

    An R and D work of a superconducting (SC) cavity for the high intensity proton linac has begun at JAERI in collaboration with KEK. The RF field calculation and the structural analysis have been made to determine the cavity shape in the proton energy range between 100 and 1500 MeV. The results indicate the feasibility of a SC proton linac. A vertical test stand with clean room, water rinsing system, cavity evacuation pumping system, cryostat and data acquisition system has been installed to demonstrate the cavity performance. A single cell cavity of β=0.5 has been fabricated and tested at the test stand to obtain the Q-value and the maximum surface electric field strength. The measured Q-values have been found to be high enough for our requirement while the field strength was limited to about 75% of the specification by the multipacting. We describe the preliminary design of the SC cavity, the overview of the vertical test stand and experimental results of the single cell cavity. (author)

  14. Optimized Multi-Ion Cavity Coupling

    Science.gov (United States)

    Begley, Stephen; Vogt, Markus; Gulati, Gurpreet Kaur; Takahashi, Hiroki; Keller, Matthias

    2016-06-01

    Recent technological advances in cavity quantum electrodynamics (CQED) are paving the way to utilize multiple quantum emitters confined in a single optical cavity. In such systems, it is crucially important to control the quantum mechanical coupling of individual emitters to the cavity mode. In this regard, combining ion trap technologies with CQED provides a particularly promising approach due to the well-established motional control over trapped ions. Here, we experimentally demonstrate coupling of up to five trapped ions in a string to a high-finesse optical cavity. By changing the axial position and spacing of the ions in a fully deterministic manner, we systematically characterize their coupling to the cavity mode through visibility measurements of the cavity emission. In good agreement with the theoretical model, the results demonstrate that the geometrical configuration of multiple trapped ions can be manipulated to obtain optimal cavity coupling. Our system presents a new ground for exploring CQED with multiple quantum emitters, enabled by the highly controllable collective light-matter interaction.

  15. Resonant-cavity antenna for plasma heating

    International Nuclear Information System (INIS)

    This patent describes a magnetic confinement plasma device having a plasma. The plasma is immersed in a strong magnetic field and confined within an evacuated plasma chamber. A wave launcher for launching electromagnetic waves in the range of frequencies of 10 MHz to 200 MHz energizes and thereby heats the plasma. The wave launcher is spaced-apart from the plasma. The wave launcher comprises: a resonant cavity, including resonant chamber walls for containing electromagnetic fields; connection means connecting the resonant cavity to a transmission line carrying electromagnetic wave energy to the resonant cavity; at least one capacitive reactive element, and at least one inductive reactive element disposed within the resonant cavity; the capacitive reactive member separated from the chamber walls of the resonant cavity by a first predefined gap, with the capacitive reactive member and the chamber walls of the resonant cavity oriented approximately tangential to the strong magnetic field; the capacitive and the inductive reactive elements spaced apart from the plasma a second predetermined distance which at least partially determines the frequency of the launched waves; and the resonant cavity cooperating with the capacitive and the inductive reactive elements so as to launch electromagnetic waves in the range of frequencies, toward the plasma

  16. Construction of cavity fabrication facility in KEK (2)

    International Nuclear Information System (INIS)

    In developing superconducting cavities for accelerator which are major components of the International Linear Collider (ILC), electron beam welding (EBW) is absolutely necessary because Nb material is used for cavities. The technology of EBW influences the cavity performance that is cavity accelerator gradient. Because of EBW in the equator part of cavities and large amount of process is needed for cavity manufacturing process. In KEK we constructed the cavity fabrication facility which is a pilot plant for the superconducting cavity processing technology. As of March in 2010, clean room was completed and the major equipment, the EBW and CP treatment equipment, have been installed in the clean room in April, 2011. (author)

  17. Demonstration of superconducting micromachined cavities

    International Nuclear Information System (INIS)

    Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing

  18. Cancer of the oral cavity

    International Nuclear Information System (INIS)

    Squamous cell carcinomas of the oral cavity are curable. When early tumor (T1 and T2) is diagnosed and treated, cure rates by surgery or irradiation are high. The choice of therapeutic modalities for these lesions is complex and depends on the site of origin and size of the tumor, the presence or absence of nodal metastases, and the age, physical, medical, and socioeconomic status of the patient. Other factors include the willingness of the patient to return for a protracted course of radiation therapy, the skill of the physician, and the relative morbidity and cosmesis of the two forms of treatment. In general, surgery may be considered for early (T1) lesions if the deformity resulting from surgery is minimal. If resection involves major morbidity, such as a deformity that alters cosmesis or the function of the speech and swallowing mechanisms, then radiation therapy is preferred. For medium-sized (T2) tumors, superficial radiation therapy is the treatment of choice, for it controls the disease and preserves normal function and anatomy. Surgery is reserved for radiation failures. Extensive disease (T3 and T4) often associated with bone and muscle involvement and cervical lymph node metastases is rarely curable by radiation therapy or surgery alone; a combined approach using radiation therapy and surgery is therefore the procedure of choice

  19. Demonstration of superconducting micromachined cavities

    Energy Technology Data Exchange (ETDEWEB)

    Brecht, T., E-mail: teresa.brecht@yale.edu; Reagor, M.; Chu, Y.; Pfaff, W.; Wang, C.; Frunzio, L.; Devoret, M. H.; Schoelkopf, R. J. [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States)

    2015-11-09

    Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing.

  20. Demonstration of superconducting micromachined cavities

    Science.gov (United States)

    Brecht, T.; Reagor, M.; Chu, Y.; Pfaff, W.; Wang, C.; Frunzio, L.; Devoret, M. H.; Schoelkopf, R. J.

    2015-11-01

    Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing.

  1. FPGA based real time RF cavity simulator for superconducting RF cavity

    International Nuclear Information System (INIS)

    RF cavity is one of the most important component in an accelerator, it is used for producing appropriate electromagnetic fields to accelerate the charged particles. The response of RF cavity to an input RF signal depends on the various operating conditions. Actual operating conditions of RF cavity are difficult to create in lab and also RF cavity is not easily available which limits the study and testing of RF systems that involve RF cavity. This calls for the requirement of a real time hardware model of the RF cavity which can be integrated with other RF systems for their testing in lab. This limitation is even more severe for superconducting RF cavities which need to be operated with the required cryogenics. Thus a real time hardware model of the superconducting RF cavity has been realized on FPGA. Real time RF Cavity simulator can be used to study the response of RF cavity under various operating conditions and for testing and optimization of other RF sub-systems particularly the Low Level RF feedback control systems in lab

  2. The nasal cavity microbiota of healthy adults

    OpenAIRE

    Bassis, Christine M.; Tang, Alice L.; Young, Vincent B.; Pynnonen, Melissa A

    2014-01-01

    Background The microbiota of the nares has been widely studied. However, relatively few studies have investigated the microbiota of the nasal cavity posterior to the nares. This distinct environment has the potential to contain a distinct microbiota and play an important role in health. Results We obtained 35,142 high-quality bacterial 16S rRNA-encoding gene sequence reads from the nasal cavity and oral cavity (the dorsum of the tongue and the buccal mucosa) of 12 healthy adult humans and dep...

  3. Clamshell microwave cavities having a superconductive coating

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, D. Wayne (Los Alamos, NM); Arendt, Paul N. (Los Alamos, NM); Piel, Helmut (Wuppertal, DE)

    1994-01-01

    A microwave cavity including a pair of opposing clamshell halves, such halves comprised of a metal selected from the group consisting of silver, copper, or a silver-based alloy, wherein the cavity is further characterized as exhibiting a dominant TE.sub.011 mode is provided together with an embodiment wherein the interior concave surfaces of the clamshell halves are coated with a superconductive material. In the case of copper clamshell halves, the microwave cavity has a Q-value of about 1.2.times.10.sup.5 as measured at a temperature of 10K and a frequency of 10 GHz.

  4. Cavity-Controlled Chemistry in Molecular Ensembles

    Science.gov (United States)

    Herrera, Felipe; Spano, Frank C.

    2016-06-01

    The demonstration of strong and ultrastrong coupling regimes of cavity QED with polyatomic molecules has opened new routes to control chemical dynamics at the nanoscale. We show that strong resonant coupling of a cavity field with an electronic transition can effectively decouple collective electronic and nuclear degrees of freedom in a disordered molecular ensemble, even for molecules with high-frequency quantum vibrational modes having strong electron-vibration interactions. This type of polaron decoupling can be used to control chemical reactions. We show that the rate of electron transfer reactions in a cavity can be orders of magnitude larger than in free space for a wide class of organic molecular species.

  5. RF cavity evaluation with the code SUPERFISH

    International Nuclear Information System (INIS)

    The computer code SUPERFISH calculates axisymmetric rf fields and is most applicable to re-entrant cavities of an Alvarez linac. Some sample results are shown for the first Alvarez's in NUMATRON project. On the other hand the code can also be effectivily applied to TE modes excited in an RFQ linac when the cavity is approximately considered as positioning at an infinite distance from the symmetry axis. The evaluation was made for several RFQ cavities, models I, II and a test linac named LITL, and useful results for the resonator design were obtained. (author)

  6. Micro-Cavity Fluidic Dye Laser

    DEFF Research Database (Denmark)

    Helbo, Bjarne; Kristensen, Anders; Menon, Aric Kumaran

    2003-01-01

    We have successfully designed, fabricated and characterized a micro-cavity fluidic dye laser with metallic mirrors, which can be integrated with polymer based lab-on-a-chip microsystems without further processing steps. A simple rate-equation model is used to predict the average pumping power...... threshold for lasing as function of cavity-mirror reflectance, laser dye concentration and cavity length. The laser device is characterized using the laser dye Rhodamine 6G dissolved in ethanol. Lasing is observed, and the influence of dye concentration is investigated....

  7. Cavity-controlled chemistry in molecular ensembles

    CERN Document Server

    Herrera, Felipe

    2015-01-01

    The demonstration of strong and ultrastrong coupling regimes of cavity QED with polyatomic molecules has opened new routes to control chemical dynamics at the nanoscale. We show that strong resonant coupling of a cavity field with an electronic transition can effectively decouple collective electronic and nuclear degrees of freedom in a disordered molecular ensemble, even for molecules with high-frequency quantum vibrational modes having strong electron-vibration interactions. This type of polaron decoupling can be used to control chemical reactions. We show that the rate of electron transfer reactions in a cavity can be orders of magnitude larger than in free space, for a wide class of organic molecular species.

  8. Shallow Cavities in Multiple-Planet Systems

    OpenAIRE

    Duffell, Paul C.; Dong, Ruobing

    2014-01-01

    Large cavities are often observed in protoplanetary disks, which might suggest the presence of planets opening gaps in the disk. Multiple planets are necessary to produce a wide cavity in the gas. However, multiple planets may also be a burden to the carving out of very deep gaps. When additional planets are added to the system, the time-dependent perturbations from these additional satellites can stir up gas in the gap, suppressing cavity opening. In this study, we perform two-dimensional nu...

  9. LHC Crab Cavity Coupler Test Boxes

    CERN Document Server

    Mitchell, James; Burt, Graeme; Calaga, Rama; Macpherson, Alick; Montesinos, Eric; Silva, Subashini; Tutte, Adam; Xiao, Binping

    2016-01-01

    The LHC double quarter wave (DQW) crab cavities have two different types of Higher Order Mode (HOM) couplers in addition to a fundamental power coupler (FPC). The FPC requires conditioning, so to achieve this we have designed a radio-frequency (RF) quarter wave resonator to provide high transmission between two opposing FPCs. For the HOM couplers we must ensure that the stop-band filter is positioned at the cavity frequency and that peak transmission occurs at the same frequencies as the strongest HOMs. We have designed two test boxes which preserve the cavity spectral response in order to test the couplers.

  10. Coherent cavity networks with complete connectivity

    OpenAIRE

    Kyoseva, Elica S.; Beige, Almut; Kwek, Leong Chuan

    2011-01-01

    When cavity photons couple to an optical fiber with a continuum of modes, they usually leak out within a finite amount of time. However, if the fiber is about one meter long and linked to a mirror, photons bounce back and forth within the fiber on a much faster time scale. As a result, {\\em dynamical decoupling} prevents the cavity photons from entering the fiber. In this paper we use the simultaneous dynamical decoupling of a large number of distant cavities from the fiber modes of linear op...

  11. Q degradations in superconducting niobium cavities

    International Nuclear Information System (INIS)

    In the past year, several laboratories around the world have observed degradations of the Q value of superconducting niobium cavities made from high thermal conductivity niobium under certain cooldown conditions. Especially under slow cooldown or warmup to temperatures < 200 K of larger systems severe degradations have been reported. A systematic study of the influence of the cooldown speed, warmup conditions, multiple cooldowns and chemical surface treatment on cavity performance of cavities manufactured from niobium of different purity has been conducted. Possible cures such as anodic oxidation are being explored and results of these investigations are reported

  12. Entanglement of separate nitrogen-vacancy centers coupled to a whispering-gallery mode cavity

    CERN Document Server

    Yang, W L; Feng, M; Du, J F

    2010-01-01

    We present a quantum electrodynamical model involving nitrogen-vacancy centers coupled to a whispering-gallery mode cavity. Two schemes are considered to create W state and Bell state, respectively. One of the schemes makes use of the Raman transition with the cavity field virtually excited; The other enables the Bell state preparation and quantum information transfer by virtue of dark state evolution and adiabatic passage, which is tolerant to ambient noise and experimental parameter fluctuations. We justify our schemes by considering the experimental feasibility and challenge using currently available technology.

  13. Efeito das cipselas de Cichorium intybus em ratinhos expostos a CCI4

    OpenAIRE

    Oliveira, Sónia Marlene Rodrigues

    2009-01-01

    Cichorium intybus é amplamente utilizada na medicina tradicional devido aos seus supostos efeitos hepatoprotectores. Este trabalho teve por objectivo estudar os possíveis efeitos protectores do extracto de cipselas (frutos) de C. intybus no fígado, rim, baço, testículo e epidídimo de ratinhos. Realizaram-se análises histopatológicas e bioquímicas. Os efeitos protectores destas cipselas foram estudados por comparação com os controlos negativo e positivo, NaCl 0,9% e CCl4 em duas...

  14. Effect of Extension and Type of Composite-Restored Class II Cavities on Biomechanical Properties of Teeth: A Three Dimensional Finite Element Analysis.

    Directory of Open Access Journals (Sweden)

    Azam Valian

    2015-04-01

    Full Text Available Controversy exists regarding cavity preparation for restoration of interproximal caries in posterior teeth in terms of preserving the tooth structure and suitable stress distribution. This study aimed to assess the effect of extension and type of class II cavities and the remaining tooth structure in maxillary premolars restored with composite resin on the biomechanical properties of teeth using finite element method (FEM.Using FEM, eight three-dimensional (3D models of class II cavities in maxillary premolars with variable mesiodistal (MD dimensions, variable thickness of the residual wall in-between the mesial and distal cavities and different locations of the wall were designed. Other dimensions were the same in all models. Cavities were restored with composite resin. A load equal to the masticatory force (200N was applied to the teeth. Finite element analysis (FEA was used to calculate the von Mises stress.Stress in the enamel margin increased by increasing the MD dimensions of the cavities. Deviation of the residual wall between the mesial and distal cavities from the tooth center was found to be an important factor in increasing stress concentration in the enamel. Increasing the MD dimensions of the cavity did not cause any increase in stress concentration in dentin.Increasing the MD dimensions of the cavities, decreasing the thickness of the residual wall between the mesial and distal cavities and its deviation from the tooth center can increase stress concentration in the enamel but not in dentin.

  15. Perturbing Open Cavities: Anomalous Resonance Frequency Shifts in a Hybrid Cavity-Nanoantenna System.

    Science.gov (United States)

    Ruesink, Freek; Doeleman, Hugo M; Hendrikx, Ruud; Koenderink, A Femius; Verhagen, Ewold

    2015-11-13

    The influence of a small perturbation on a cavity mode plays an important role in fields like optical sensing, cavity quantum electrodynamics, and cavity optomechanics. Typically, the resulting cavity frequency shift directly relates to the polarizability of the perturbation. Here, we demonstrate that particles perturbing a radiating cavity can induce strong frequency shifts that are opposite to, and even exceed, the effects based on the particles' polarizability. A full electrodynamic theory reveals that these anomalous results rely on a nontrivial phase relation between cavity and nanoparticle radiation, allowing backaction via the radiation continuum. In addition, an intuitive model based on coupled mode theory is presented that relates the phenomenon to retardation. Because of the ubiquity of dissipation, we expect these findings to benefit the understanding and engineering of a wide class of systems. PMID:26613442

  16. Striped-double cavity fabry-perot interferometers using both glass and air cavities

    Energy Technology Data Exchange (ETDEWEB)

    Perry, S; Steinmetz, L

    1998-07-08

    We have used piezo-driven Fabry-Perot interferometers in the past far many continuous velocity-time measurements of fast moving surfaces. In order to avoid the annoying drift of some of these devices, we have developed and used inexpensive, solid glass, striped etalons with lengths up to 64 mm. Usable apertures are 35 mm by 80 mm with a finess of 25. A roundabout technique was devised for double cavity operation. We built a passive thermal housing for temperature stability, with tilt and height adjustments. We have also developed and used our first fixed etalon air-spaced cavity with a rotatable glass double- cavity insert. The rotation allows the referee cavity fractional order to be adjusted separately from that of the main cavity. It needs very little thermal protection, and eliminates the need for a roundabout scheme for double cavity operation, but is more costly than the solid glass version I

  17. Efeito da urina de vaca no estado nutricional da alface

    Directory of Open Access Journals (Sweden)

    Nelson Licínio C. de Oliveira

    2010-08-01

    Full Text Available Existem diversos relatos da utilização da urina de vaca em hortaliças, todavia sua eficácia carece de comprovação. Objetivou-se avaliar o efeito da urina de vaca no estado nutricional da alface. O experimento foi constituído de 12 tratamentos, esquema de parcelas subdivididas, em blocos ao acaso, com quatro repetições. Nas parcelas foram alocadas as vias de aplicação (solo ou foliar e nas subparcelas as concentrações das soluções (0,00; 0,25; 0,50; 0,75; 1,00 e 1,25% v/v. Aplicou-se 60 mL de solução/planta, divididos em cinco aplicações de 5; 5; 10; 20 e 20 mL/planta, aos 7, 14, 21, 28 e 35 após o transplante, respectivamente. Durante o ciclo avaliou-se o índice SPAD e na colheita a massa da matéria seca de cabeça (MSCA e os teores de N, P, K, Ca, Mg, S, Na, Zn, Fe, Mn, Cu e B na matéria seca das folhas (MSF, caule (MSC e raízes (MSR. Em ambas as vias de aplicação o índice SPAD apresentou incremento linear às concentrações e resposta quadrática ao longo do tempo. A MSCA teve comportamento linear às concentrações, com aumento de 25,9 e 35,4% nas aplicações via foliar e solo, respectivamente. Não houve efeito de concentrações sobre teores de nutrientes na MSF e MSC. Na MSR, via solo, os teores de P e K apresentaram pontos de máximo enquanto Fe e Mn de mínimo; o Na apresentou incremento linear às concentrações via foliar. Os efeitos da urina sobre o crescimento da alface provavelmente são devidos a fatores outros que não somente a quantidade de nutrientes veiculados nas soluções.

  18. Ion-cavity system for quantum networks

    International Nuclear Information System (INIS)

    Full text: A single atom interacting with a single mode of a cavity allows us to probe the quantum interaction between light and matter. In the context of quantum networks, such a system can provide an interface between stationary and flying qubits, making it possible for single photons to transport quantum information between the network nodes. We study a single 40Ca+ ion trapped inside a high-finesse optical resonator. First, we demonstrate and characterize a single-photon source, in which a vacuum-stimulated Raman process transfers atomic population between two Zeeman states of the ion, creating a single photon in the cavity. We evaluate the photon statistics by measuring the second-order correlation function. Moreover, we obtain the photon temporal profile and investigate the dynamics of the process. Secondly, we perform Raman spectroscopy using the cavity. Residual motion of the ion introduces motional sidebands in the Raman spectrum and thus offers prospects for cavity-assisted cooling. (author)

  19. High-Q ferrite-tuned cavity

    International Nuclear Information System (INIS)

    Rapid cycling proton synchrotrons, such as the proposed LAMPF II accelerator, require approximately 10 MV per turn rf with 17% tuning range near 50 MHz. The traditional approach to ferrite-tuned cavities uses a ferrite which is longitudinally biased (rf magnetic field parallel to bias field). This method leads to unacceptably high losses in the ferrite. At Los Alamos, we are developing a cavity with transverse bias (rf magnetic field perpendicular to the bias field) that makes use of the tensor permeability of the ferrite. Initial tests of a small (10-cm-diam) quarter-wave singly re-entrant cavity tuned by several different ferrites indicate that the losses in the ferrite can be made negligible compared with the losses due to the surface resistivity of the copper cavity

  20. Working on an LHC superconducting cavity

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    The delicate superconducting equipment for CERN’s LHC collider has to be assembled in ultra-clean conditions to safeguard performance. Here we see the power supply being installed on one of the superconducting cavities.

  1. section of an accelerating cavity from LEP

    CERN Multimedia

    This is a section of an accelerating cavity from LEP, cut in half to show the layer of niobium on the inside. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment. These challenging requirements pushed European industry to new achievements. 256 of these cavities are now used in LEP to double the energy of the particle beams.

  2. On Catastrophe and Cavitation for Spherical Cavity

    Institute of Scientific and Technical Information of China (English)

    MingJIN; KefuHUANG; 等

    1999-01-01

    This work deals with catastrophe of a spherical cavity and cavitation of a spherical cavity for Hooke material with 1/2 Poisson's ratio.A nonlinear problem.which is the Cauchy traction problem,is solved analytically.The governing equations are written on the deformed region or on the present configuration.And the conditions are described on moving boundary.A closed form solution is found.Furthermore,a bifurcation solution in closed form is given from the trivial homogeneous solution of a solid sphere.The results indicate that there is a tangent bifurcation on the displacement-load curve for a sphere with a cavity.On the tangent bifurcation point,the cavity grows up suddenly,which is a kind of catastrophe,And there is a pitchfork bifurcation on the displacement-load curve for a solid sphere.On the pitchfork bifurcation point.there is a cavitation in the solid sphere.

  3. Photon filters in a microwave cavity

    CERN Document Server

    Larson, J

    2003-01-01

    In an earlier paper we have concluded that time-dependent parameters in atom-mode interaction can be utilized to modify the quantum field in a cavity. When an atom shoots through the cavity field, it is expected to experience a trigonometric time dependence of its coupling constant. We investigate the possibilities this offers to modify the field. As a point of comparison we use the solvable Rosen-Zener model, which has parameter dependencies roughly similar to the ones expected in a real cavity. We do confirm that by repeatedly sending atoms through the cavity, we can obtain filters on the photon states. Highly non-classical states can be obtained. We find that the Rosen-Zener model is more sensitive to the detuning than the case of a trigonometric coupling.

  4. Cavity-enhanced spectroscopy and sensing

    CERN Document Server

    Loock, Hans-Peter

    2014-01-01

    The book reviews the dramatic recent advances in the use of optical resonators for high sensitivity and high resolution molecular spectroscopy as well as for chemical, mechanical and physical sensing.  It encompasses a variety of cavities including those made of two or more mirrors, optical fiber loops, fiber gratings and spherical cavities. The book focuses on novel techniques and their applications. Each chapter is written by an expert and/or pioneer in the field. These experts also provide the theoretical background in optics and molecular physics where needed. Examples of recent breakthroughs include the use of frequency combs (Nobel prize 2005) for cavity enhanced sensing and spectroscopy, the use of novel cavity materials and geometries, the development of optical heterodyne detection techniques combined to active frequency-locking schemes. These methods allow the use and interrogation of optical resonators with a variety of coherent light sources for trace gas detection and sensing of strain, temperat...

  5. Malignant melanoma of the oral cavity

    Directory of Open Access Journals (Sweden)

    Ebenezer Jagadish

    2006-01-01

    Full Text Available Oral malignant melanoma is a rare disease. The common sites of its occurrence are the palate and gingiva with the maxillary arch being affected 80% of the time. Because of their presence at relatively obscure areas in the oral cavity, most of the malignant melanomas of the oral cavity are diagnosed at a late stage. These lesions are associated with poor prognosis. The dental clinician must therefore carefully examine the head, neck, and oral cavity, and any pigmented lesion that may exhibit growth potential must be biopsied. This article describes a case of malignant melanoma that was present in the oral cavity and briefly reviews the relevant literature that explains the nature of this lesion.

  6. Photonic crystal cavities with metallic Schottky contacts

    International Nuclear Information System (INIS)

    We report about the fabrication and analysis of high Q photonic crystal cavities with metallic Schottky-contacts. The structures are based on GaAs n-i membranes with an InGaAs quantum well in the i-region and nanostructured low ohmic metal top-gates. They are designed for photocurrent readout within the cavity and fast electric manipulations. The cavity structures are characterized by photoluminescence and photocurrent spectroscopy under resonant excitation. We find strong cavity resonances in the photocurrent spectra and surprisingly high Q-factors up to 6500. Temperature dependent photocurrent measurements in the region between 4.5 K and 310 K show an exponential enhancement of the photocurrent signal and an external quantum efficiency up to 0.26

  7. Reducing the convective losses of cavity receivers

    Science.gov (United States)

    Flesch, Robert; Grobbel, Johannes; Stadler, Hannes; Uhlig, Ralf; Hoffschmidt, Bernhard

    2016-05-01

    Convective losses reduce the efficiency of cavity receivers used in solar power towers especially under windy conditions. Therefore, measures should be taken to reduce these losses. In this paper two different measures are analyzed: an air curtain and a partial window which covers one third of the aperture opening. The cavity without modifications and the usage of a partial window were analyzed in a cryogenic wind tunnel at -173°C. The cryogenic environment allows transforming the results from the small model cavity to a large scale receiver with Gr≈3.9.1010. The cavity with the two modifications in the wind tunnel environment was analyzed with a CFD model as well. By comparing the numerical and experimental results the model was validated. Both modifications are capable of reducing the convection losses. In the best case a reduction of about 50 % was achieved.

  8. Wakefield Damping for the CLIC Crab Cavity

    Energy Technology Data Exchange (ETDEWEB)

    Ambattu, P.K.; Burt, G.; Dexter, A.C.; Carter, R.G.; /Cockcroft Inst. Accel. Sci. Tech. /Lancaster U.; Khan, V.; Jones, R.M.; /Cockcroft Inst. Accel. Sci. Tech. /Manchester U.; Dolgashev, V.; /SLAC

    2011-12-01

    A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

  9. Wakefield damping for the CLIC crab cavity

    CERN Document Server

    Ambattu, P K; Dexter, A C; Carter, R G; Khan, V; Jones, R M; Dolgashev, V

    2009-01-01

    A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

  10. WAKEFIELD DAMPING FOR THE CLIC CRAB CAVITY

    CERN Document Server

    Ambattu, P; Dexter, A; Carter, R; Khan, V; Jones, R; Dolgashev, V

    2009-01-01

    A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

  11. Nb3Sn for Radio Frequency Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Godeke, A.

    2006-12-18

    In this article, the suitability of Nb3Sn to improve theperformance of superconducting Radio-Frequency (RF)cavities is discussed.The use of Nb3Sn in RF cavitiesis recognized as an enabling technology toretain a veryhigh cavity quality factor (Q0) at 4.2 K and tosignificantly improve the cavity accelerating efficiency per unitlength(Eacc). This potential arises through the fundamental properties ofNb3Sn. The properties that are extensively characterized in theliterature are, however, mainly related to improvements in currentcarrying capacity (Jc) in the vortex state. Much less is available forthe Meissner state, which is of key importance to cavities. Relevantdata, available for the Meissner state is summarized, and it is shown howthis already validates the use of Nb3Sn. In addition, missing knowledgeis highlighted and suggestions are given for further Meissner statespecific research.

  12. LEP superconducting cavities go into storage

    CERN Multimedia

    Patrice Loïez

    2001-01-01

    Superconducting radio-frequency cavities from the LEP-2 phase (1996-2000) are put into storage in the tunnel that once housed the Intersecting Storage Rings (ISR), the world’s first proton collider, located at CERN.

  13. Barrier Cavities in the Brookhaven AGS

    International Nuclear Information System (INIS)

    In collaboration with KEK two barrier cavities, each generating 40 kV per turn have been installed in the Brookhaven AGS. Machine studies are described and their implications for high intensity operations are discussed

  14. Radiotherapy for Oral Cavity Cancer

    International Nuclear Information System (INIS)

    Eighty five patients of oral cavity cancer, treated with radiation at the Department of Therapeutic Radiology, Korea Cancer Center Hospital, during the period from March 1985 to September 1990 were analyzed retrospectively. Among 85 patients, 37 patients were treated with radiation only and 48 patients were treated with radiation following surgery And 70 patients received external irradiation only by 60Co with or without electron, the others were 7 patients for external irradiation plus interstitial implantation and 8 patients for external irradiation plus oral cone electron therapy. Primary sites were mobile tongue for 40 patients, mouth floor for 17 patients, palate for 12 patients, gingiva including retromolar trigone for 10 patients, buccal mucosa for 5 patients, and lip for 1 patient. According to pathologic classification, squamous cell carcinoma was the most common (77 patients). According to AJC TNM stage, stage I + II were 28 patients and stage III + IV were 57 patients. Acturial overall survival rate at 3 years was 43.9%, 3 year survival rates were 60.9% for stage I + II, and 23.1% for stage III + IV, respectively. As a prognostic factor, primary T stage was a significant factor (p<0.01). The others, age, location, lymph node metastasis, surgery, radiation dose, and cell differentiation were not statistically significant. Among those factors, radiation plus surgery was more effective than radiation only in T3 + T4 or in any N stage although it was not statistically sufficient(p<0.1). From those results, it was conclusive that definitive radiotherapy was more effective than surgery especially in the view of pertaining of anatomical integrity and function in early stage, and radiation plus surgery was considered to be better therapeutic tool in advanced stage

  15. A ''monochromatic'' RF-cavity

    International Nuclear Information System (INIS)

    The Electron-Positron-Accumulation ring (EPA)in the LEP injector chain acts as a particle buffer between the fast-cycling (100Hz) LEP Injector Linac (LIL) and the slow-cycling (0.8 Hz) CERN Proton Synchrotron (CPS). EPA has a circumference of 126m and has operated after start-up in June 1986 at 500 MeV. Only e- have been stored while e+ operation is scheduled for March 1987. The nominal EPA intensities are 2.5 X 1010 e- per bunch corresponding to a total current of 76 mA and 38 mA in 8 bunches. However, a current of 240 MA has already been stored. A nominal LIL pulse is 12 ns long but 25 ns is typical. The intensity is 9/pulse. In order to have a large longitudinal acceptance the lowest possible harmonic number h=8 was chosen for EPA yielding frf=19 MHz. The maximum r.f. voltage Vrf=50 kV is determined by the momentum acceptance (+-1.2%) of the bucket required by the e- LIL pulse. The longitudinal matching to the CPS did not impose further constraints except that adiabatic reduction of Vrf to about 10 kV prior to ejection is required if the CPS accelerates with frf=7.6 MHz. Since the 8 bunches are closely spaced, parasitic higher modes in the cavity have no time to decay. Therefore, efficient damping of these modes is required. Care was taken that other ring elements would not produce high-Q parasitic resonances

  16. The emission properties of an atom inside a cavity when manipulating the atoms outside the cavity

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen; YE Liu; XIONG Kuang-wei; ZHANG Jin

    2003-01-01

    Considering three two-level atoms initially in the GHZ state, then one atom of them is put into an initially empty cavity and made resonant interaction. It is shown that the emission properties of the atom inside the cavity can be affected only when both of the atoms outside the cavity have been manipulated. This conclusion can also be generalized to n two-level atoms.

  17. Early 500 MHz prototype LEP RF Cavity with superposed storage cavity

    CERN Multimedia

    1981-01-01

    The principle of transferring the RF power back and forth between the accelerating cavity and a side-coupled storage cavity was demonstrated with this 500 MHz prototype. In LEP, the accelerating frequency was 352.2 MHz, and accelerating and storage cavities were consequently larger. See also 8002294, 8006061, 8407619X, and Annual Reports 1980, p.115; 1981, p.95; 1985, vol.I, p.13.

  18. Cavity QED on a nanofiber using a composite photonic crystal cavity

    CERN Document Server

    Yalla, Ramachandrarao; Nayak, Kali P; Hakuta, Kohzo

    2014-01-01

    We demonstrate cavity QED conditions in the Purcell regime for single quantum emitters on the surface of an optical nanofiber. The cavity is formed by combining an optical nanofiber and a nanofabricated grating to create a composite photonic crystal cavity. Using this technique, significant enhancement of the spontaneous emission rate into the nanofiber guided modes is observed for single quantum dots. Our results pave the way for enhanced on-fiber light-matter interfaces with clear applications to quantum networks.

  19. Electrically Pumped Vertical-Cavity Amplifiers

    DEFF Research Database (Denmark)

    Greibe, Tine

    2007-01-01

    In this work, the design of electrically pumped vertical cavity semiconductor optical amplifiers (eVCAs) for use in a mode-locked external-cavity laser has been developed, investigated and analysed. Four different eVCAs, one top-emitting and three bottom emitting structures, have been designed and...... discussed. The thesis concludes with recommendations for further work towards the realisation of compact electrically pumped mode-locked vertical externalcavity surface emitting lasers....

  20. Collapse of Non-Axisymmetric Cavities

    OpenAIRE

    Enriquez, Oscar R.; Peters, Ivo R.; Gekle, Stephan; Schmidt, Laura; Versluis, Michel; van der Meer, Devaraj; Lohse, Detlef

    2009-01-01

    A round disk with a harmonic disturbance impacts on a water surface and creates a non-axisymmetric cavity which collapses under the influence of hydrostatic pressure. We use disks deformed with mode m=2 to m=6. For all mode numbers we find clear evidence for a phase inversion of the cavity wall during the collapse. We present a fluid dynamics video showing high speed imaging of different modes, pointing out the characteristic features during collapse.

  1. Resonance control in SRF cavities at FNAL

    Energy Technology Data Exchange (ETDEWEB)

    Schappert, W.; Pischalnikov, Y.; /Fermilab; Scorrano, M.; /INFN, Pisa

    2011-03-01

    The Lorentz force can dynamically detune pulsed Superconducting RF cavities. Considerable additional RF power can be required to maintain the accelerating gradient if no effort is made to compensate for this detuning. Compensation systems using piezo actuators have been used successfully at DESY and elsewhere to control Lorentz Force Detuning (LFD). Recently, Fermilab has developed an adaptive compensation system for cavities in the Horizontal Test Stand, in the SRF Accelerator Test Facility, and for the proposed Project X.

  2. Comments on Crab Cavity HOM Power

    CERN Document Server

    Calaga, Rama; CERN. Geneva. ATS Department

    2013-01-01

    Due to large beam current in the LHC and the luminosity upgrade (HL-LHC) which will further double the current, higher order mode (HOM) power of the superconducting crab cavities can easily reach a few kilowatts in the worst case scenario of resonant excitation. This report aims at estimating the HOM power to be extracted for a generalized HOM of crab cavity with realistic filling schemes in the LHC.

  3. Dynamically Reconfigurable Photonic Crystal Nanobeam Cavities

    OpenAIRE

    Frank, Ian W.; Deotare, Parag B.; McCutcheon, Murray W.; Loncar, Marko

    2009-01-01

    Wavelength-scale, high Q-factor photonic crystal cavities have emerged as a platform of choice for on-chip manipulation of optical signals, with applications ranging from low-power optical signal processing and cavity quantum electrodynamics, to biochemical sensing. Many of these applications, however, are limited by the fabrication tolerances and the inability to precisely control the resonant wavelength of fabricated structures. Various techniques for post-fabrication wavelength trimming an...

  4. LHC Crab Cavity Progress and Outlook

    CERN Document Server

    Calaga, R

    2013-01-01

    Three novel superconducting RF crab cavity designs proposed for the LHC luminosity upgrade have rapidly progressed. First Niobium prototypes are reaching close to the design performance and beyond. The highlights of the RF test results from the prototypes along with design modifications for initial beam tests in the SPS are presented. The status of the cryomodule development, integration into the SPS and the beam tests in view of validating the crab cavity system for LHC upgrade are addressed.

  5. Impacto do efeito suporte e do efeito informação sobre a recuperação de reservas

    Directory of Open Access Journals (Sweden)

    Cruz Júnior Antônio Camilo

    2001-01-01

    Full Text Available Apesar do desenvolvimento de modernas técnicas de tratamento de minérios, a estimativa de teores ainda é uma parte importante na avaliação de reservas minerais. Nesse trabalho é apresentado o formalismo das funções de recuperação (curvas tonelagem x teor com o objetivo de esclarecer os seus efeitos inerentes à atividade mineira, tais como: o efeito suporte e o efeito informação. Exemplos práticos, embora acadêmicos, são apresentados de modo a tornar mais didáticos e aplicáveis os textos originais de Matheron, 1981 e 1984. O estudo do efeito suporte e do efeito informação, considerando que a seleção de blocos é feita sem restrições (seleção livre, mostrou que a mudança de suporte e que a tomada de decisão sobre valores estimados degradam significativamente as curvas de parametrização, no sentido de perda econômica.

  6. Beam induced RF cavity transient voltage

    International Nuclear Information System (INIS)

    We calculate the transient voltage induced in a radio frequency (RF) cavity by the injection of a relativistic bunched beam into a circular accelerator. A simplified model of the beam induced voltage, using a single tone current signal, is generated and compared with the voltage induced by a more realistic model of a point-like bunched beam. The high Q limit of the bunched beam model is shown to be related simply to the simplified model. Both models are shown to induce voltages at the resonant frequency ωr of the cavity and at an integer multiple of the bunch revolution frequency (i.e. the accelerating frequency for powered cavity operation) hω0. The presence of two nearby frequencies in the cavity leads to a modulation of the carrier wave exp(jhω0t). A special emphasis is placed in this paper on studying the modulation function. These models prove useful for computing the transient voltage induced in superconducting RF cavities, which was the motivation behind this research. The modulation of the transient cavity voltage discussed in this paper is the physical basis of the recently observed and explained new kind of longitudinal rigid dipole mode which differs from the conventional Robinson mode

  7. Study of CSR longitudinal bunch compression cavity

    International Nuclear Information System (INIS)

    The scheme of longitudinal bunch compression cavity for the Cooling Storage Ring (CSR)is an important issue. Plasma physics experiments require high density heavy ion beam and short pulsed bunch,which can be produced by non-adiabatic compression of bunch implemented by a fast compression with 90 degree rotation in the longitudinal phase space. The phase space rotation in fast compression is initiated by a fast jump of the RF-voltage amplitude. For this purpose, the CSR longitudinal bunch compression cavity, loaded with FINEMET-FT-1M is studied and simulated with MAFIA code. In this paper, the CSR longitudinal bunch compression cavity is simulated and the initial bunch length of 238U72+ with 250 MeV/u will be compressed from 200 ns to 50 ns.The construction and RF properties of the CSR longitudinal bunch compression cavity are simulated and calculated also with MAFIA code. The operation frequency of the cavity is 1.15 MHz with peak voltage of 80 kV, and the cavity can be used to compress heavy ions in the CSR. (authors)

  8. Laser plasma interactions in fused silica cavities

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Xianzhong; Mao, Xianglei; Mao, Samuel S.; Yoo, Jong H.; Greif, Ralph; Russo, Richard E.

    2003-06-24

    The effect of laser energy on formation of a plasma inside a cavity was investigated. The temperature and electron number density of laser-induced plasmas in a fused silica cavity were determined using spectroscopic methods, and compared with laser ablation on a flat surface. Plasma temperature and electron number density during laser ablation in a cavity with aspect ratio of 4 increased faster with irradiance after the laser irradiance reached a threshold of 5 GW/cm{sup 2}. The threshold irradiance of particulate ejection was lower for laser ablation in a cavity compared with on a flat surface; the greater the cavity aspect ratio, the lower the threshold irradiance. The ionization of silicon becomes saturated and the crater depths were increased approximately by an order of magnitude after the irradiance reached the threshold. Phase explosion was discussed to explain the large change of both plasma characteristics and mass removal when irradiance increased beyond a threshold value. Self-focusing of the laser beam was discussed to be responsible for the decrease of the threshold in cavities.

  9. Flux expulsion variation in SRF cavities

    CERN Document Server

    Posen, S; Romanenko, A; Melnychuk, O; Sergatskov, D A; Martinello, M; Checchin, M; Crawford, A C

    2015-01-01

    Treating a cavity with nitrogen doping significantly increases $Q_0$ at medium fields, reducing cryogenic costs for high duty factor linear accelerators such as LCLS II. N-doping also makes cavities more sensitive to increased residual resistance due to trapped magnetic flux, making it critical to either have extremely effective magnetic shielding, or to prevent flux from being trapped in the cavity during cooldown. In this paper, we report on results of a study of flux expulsion. We discuss possible ways in which flux can be pinned in the inner surface, outer surface, or bulk of a cavity, and we present experimental results studying these mechanisms. We show that grain structure appears to play a key role and that a cavity that expelled flux poorly changed to expelling flux well after a high temperature furnace treatment. We further show that after furnace treatment, this cavity exhibited a significant improvement in quality factor when cooled in an external magnetic field. We conclude with implications for ...

  10. "Fine grain Nb tube for SRF cavities"

    Energy Technology Data Exchange (ETDEWEB)

    Robert E. Barber

    2012-07-08

    Superconducting radio frequency (SRF) cavities used in charged particle linear accelerators, are currently fabricated by deep drawing niobium sheets and welding the drawn dishes together. The Nb sheet has a non-uniform microstructure, which leads to unpredictable cavity shape and surface roughness, and inconsistent "spring-back" during forming. In addition, weld zones cause hot spots during cavity operation. These factors limit linear accelerator performance and increase cavity manufacturing cost. Equal channel angular extrusion (ECAE) can be used to refine and homogenize the microstructure of Nb tube for subsequent hydroforming into SRF cavities. Careful selection of deformation and heat treatment conditions during the processing steps can give a uniform and consistent microstructure in the tube, leading to improved deformability and lower manufacturing costs. Favorable microstructures were achieved in short test samples of RRR Nb tube, which may be particularly suitable for hydroforming into SRF cavity strings. The approach demonstrated could be applicable to microstructure engineering of other tube materials including tantalum, titanium, and zirconium.

  11. Cavity Mode Frequencies and Large Optomechanical Coupling in Two-Membrane Cavity Optomechanics

    CERN Document Server

    Li, J; Malossi, N; Vitali, D

    2015-01-01

    We study the cavity mode frequencies of a Fabry-Perot cavity containing two vibrating dielectric membranes and the corresponding optomechanical coupling. Due to optical interference, extremely large optomechanical coupling of the membrane relative motion is achieved when the two membranes are placed very close to a resonance of the inner cavity formed by the two membranes, and in the limit of highly reflective membranes. The upper bound of the coupling strength is given by the optomechanical coupling associated with the much shorter inner cavity, consistently with the analysis of A. Xuereb et al., Phys. Rev. Lett. 109, 223601 (2012).

  12. Vector cavity solitons in broad area Vertical-Cavity Surface-Emitting Lasers.

    Science.gov (United States)

    Averlant, Etienne; Tlidi, Mustapha; Thienpont, Hugo; Ackemann, Thorsten; Panajotov, Krassimir

    2016-01-01

    We report the experimental observation of two-dimensional vector cavity solitons in a Vertical-Cavity Surface-Emitting Laser (VCSEL) under linearly polarized optical injection when varying optical injection linear polarization direction. The polarization of the cavity soliton is not the one of the optical injection as it acquires a distinct ellipticity. These experimental results are qualitatively reproduced by the spin-flip VCSEL model. Our findings open the road to polarization multiplexing when using cavity solitons in broad-area lasers as pixels in information technology. PMID:26847004

  13. Efeito de uma classe de movimento em pessoas idosas institucionalizados

    OpenAIRE

    Pinheira, Vítor; Coutinho, António; Martins, Cláudia; Barata, Gonçalo; Batista, Joana; Duarte, Mariana

    2011-01-01

    Objectivo: Avaliar os efeitos de uma classe de movimento na força muscular, flexibilidade, equilíbrio, medo de queda, estado de saúde/qualidade de vida e desempenho físico, em pessoas idosas residentes em instituições para a terceira idade. Amostra: Amostra de conveniência constituída por 30 idosos, com uma média de idades de 79,40 ±1,37 anos, um IMC médio de 24,66 kg/m2 e que obtiveram uma pontuação mínima prévia de 10 pontos no Timed Up and Go Test. Material e Métodos: Estudo longitu...

  14. Entanglement dynamics of high-dimensional bipartite field states inside the cavities in dissipative environments

    Energy Technology Data Exchange (ETDEWEB)

    Tahira, Rabia; Ikram, Manzoor; Zubairy, M Suhail [Centre for Quantum Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Bougouffa, Smail [Department of Physics, Faculty of Science, Taibah University, PO Box 30002, Madinah (Saudi Arabia)

    2010-02-14

    We investigate the phenomenon of sudden death of entanglement in a high-dimensional bipartite system subjected to dissipative environments with an arbitrary initial pure entangled state between two fields in the cavities. We find that in a vacuum reservoir, the presence of the state where one or more than one (two) photons in each cavity are present is a necessary condition for the sudden death of entanglement. Otherwise entanglement remains for infinite time and decays asymptotically with the decay of individual qubits. For pure two-qubit entangled states in a thermal environment, we observe that sudden death of entanglement always occurs. The sudden death time of the entangled states is related to the number of photons in the cavities, the temperature of the reservoir and the initial preparation of the entangled states.

  15. High Field Studies on L-band Superconducting Cavities at KEK

    International Nuclear Information System (INIS)

    Several 1.3 GHz single-cell and nine-cell niobium cavities were fabricated to attain a higher maximum accelerating gradient and to understand the phenomena limiting it. Vertical cold tests at ∼1.8 K for the 4 single-cell cavities prepared by various surface treatments have been conducted 15 times. In eight of the tests, maximum accelerating gradients (Eacc, max) of more than 14 MV/m were obtained with no field emission. Furthermore, Eacc, max values of higher than 20 MV/m with a high Q0 value of ∼1010 were achieved repeatedly after heat treatment at 1400 degrees C. Once quenching was observed at Eacc, max (14 ∼ 20 MV/m), however, a common phenomenon resulting in Q0-deterioration occurred in every test. The cavity performances and the phenomenon at high fields are reported in this paper

  16. Non-destructive monitoring of Bloch oscillations in an optical cavity

    CERN Document Server

    Keßler, H; Venkatesh, B P; Georges, Ch; Hemmerich, A

    2016-01-01

    Bloch oscillations are a hallmark of coherent wave dynamics in periodic potentials. They occur as the response of quantum mechanical particles in a lattice if a weak force is applied. In optical lattices with their perfect periodic structure they can be readily observed and employed as a quantum mechanical force sensor, for example, for precise measurements of the gravitational acceleration. However, the destructive character of the measurement process in previous experimental implementations poses serious limitations for the precision of such measurements. In this article we show that the use of an optical cavity operating in the regime of strong cooperative coupling allows one to directly monitor Bloch oscillations of a cloud of cold atoms in the light leaking out of the cavity. Hence, with a single atomic sample the Bloch oscillation dynamics can be mapped out, while in previous experiments, each data point required the preparation of a new atom cloud. The use of a cavity-based monitor should greatly impro...

  17. Multiparty Quantum Secret Sharing of Classical Message using Cavity Quantum Electrodynamic System

    Institute of Scientific and Technical Information of China (English)

    HAN Lian-Fang; LIU Yi-Min; ZHANG Zhan-Jun

    2006-01-01

    @@ An experimental feasible scheme of multiparty secret sharing of classical messages is proposed, based on a cavity quantum electrodynamic system. The secret messages are imposed on atomic Bell states initially in the sender's possession by local unitary operations. By swapping quantum entanglement of atomic Bell states, the secret messages are split into several parts and each part is distributed to a separate party. In this case, any subset of the entire party group can not read out the secret message but the entirety via mutual cooperations. In this scheme, to discriminate atomic Bell states, additional classical fields are employed besides the same highly-detuned single-mode cavities used to prepare atomic Bell states. This scheme is insensitive to the cavity decay and the thermal field, and usual joint Bell-state measurements are unnecessary.

  18. Efeito de doses de paclobutrazol na cultura do alho

    Directory of Open Access Journals (Sweden)

    Resende Geraldo Milanez de

    2002-01-01

    Full Text Available O trabalho foi realizado no período de maio a outubro de 1991 no campo experimental do setor de olericultura da Ufla, Lavras, MG, com o objetivo de avaliar a influência de doses de paclobutrazol sobre o controle do pseudoperfilhamento e nas características morfológicas e comerciais do alho (Allium sativum L.. Utilizou-se o delineamento experimental de blocos ao acaso, com quatro doses de paclobutrazol (0, 500, 1.000 e 1.500 mg de i.a. L-1, em cinco repetições. Com o aumento das concentrações de paclobutrazol, houve uma redução na altura das plantas e no número de folhas por planta aos 60 e 90 dias após o plantio. A produtividade total e comercial de bulbos apresentou efeito significativo em relação às doses de paclobutrazol, sendo as concentrações de 725 e 778 mg L-1 as que proporcionaram as maiores produtividades. A porcentagem de bulbos pseudoperfilhados evidenciou efeito quadrático com o incremento das doses de paclobutrazol, cuja concentração de 1.163 mg L-1 propiciou maior redução na porcentagem de pseudoperfilhamento. A concentração de 744 mg L-1 de paclobutrazol proporcionou o maior peso médio de bulbo; e em relação a número de bulbilhos por bulbo, não se verificaram diferenças significativas entre os tratamentos.

  19. Teleportation of a Weak Coherent Cavity Field State

    Science.gov (United States)

    Cardoso, Wesley B.; Qiang, Wen-Chao; Avelar, Ardiley T.

    2016-07-01

    In this paper we propose a scheme to teleport a weak coherent cavity field state. The scheme relies on the resonant atom-field interaction inside a high-Q cavity. The mean photon-number of the cavity field is assumed much smaller than one, hence the field decay inside the cavity can be effectively suppressed.

  20. Teleportation of atomic states with a weak coherent cavity field

    Institute of Scientific and Technical Information of China (English)

    Zheng Shi-Biao

    2005-01-01

    A scheme is proposed for the teleportation of an unknown atomic state. The scheme is based on the resonant interaction of atoms with a coherent cavity field. The mean photon-number of the cavity field is much smaller than one and thus the cavity decay can be effectively suppressed. Another adwntage of the scheme is that only one cavity is required.

  1. Soliton laser: A computational two-cavity model

    DEFF Research Database (Denmark)

    Berg, P.; If, F.; Christiansen, Peter Leth;

    1987-01-01

    An improved computational two-cavity model of the soliton laser proposed and designed by Mollenauer and Stolen [Opt. Lett. 9, 13 (1984)] is obtained through refinements of (i) the laser cavity model, (ii) the pulse propagation in the fiber cavity, and (iii) the coupling between the two cavities. As...

  2. Teleportation of a Weak Coherent Cavity Field State

    Science.gov (United States)

    Cardoso, Wesley B.; Qiang, Wen-Chao; Avelar, Ardiley T.

    2016-02-01

    In this paper we propose a scheme to teleport a weak coherent cavity field state. The scheme relies on the resonant atom-field interaction inside a high-Q cavity. The mean photon-number of the cavity field is assumed much smaller than one, hence the field decay inside the cavity can be effectively suppressed.

  3. Control of ring lasers by means of coupled cavities

    DEFF Research Database (Denmark)

    Abitan, Haim; Andersen, Ulrik Lund; Skettrup, Torben;

    2000-01-01

    Summary form only. Coupling of optical cavities offers a means of controlling the properties of one cavity (e.g. a laser) by making adjustments to another, external cavity. In this contribution we consider a unidirectional ring laser (bow-tie laser) coupled to an external ring cavity. Using...

  4. Two cavity autoacceleration of an intense relativistic electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, P.D.; Lockner, T.R.

    1985-01-01

    Two autoacceleration cavities have been used to accelerate an 11-kA electron beam from 2 MeV to approx. =2.8 MeV. The two 40-..cap omega.. cavities each accelerated the beam by approx. =400 kV with no observable interaction between the two cavities over several cavity transmit times. 6 figs.

  5. Two cavity autoacceleration of an intense relativistic electron beam

    International Nuclear Information System (INIS)

    Two autoacceleration cavities have been used to accelerate an 11-kA electron beam from 2 MeV to approx. =2.8 MeV. The two 40-Ω cavities each accelerated the beam by approx. =400 kV with no observable interaction between the two cavities over several cavity transmit times. 6 figs

  6. Scheme for implementing quantum secret sharing via cavity QED

    Institute of Scientific and Technical Information of China (English)

    Chen Zhi-Hua; Lin Xiu-Min

    2005-01-01

    An experimentally feasible scheme for implementing quantum secret sharing via cavity quantum electrodynamics (QED) is proposed. The scheme requires the large detuning of the cavity field from the atomic transition, the cavity is only virtually excited, thus the requirement on the quality factor of the cavity is greatly loosened.

  7. Feasible schemes for preparation of all five-atom graph states

    International Nuclear Information System (INIS)

    We propose feasible schemes for preparation of all five-atom graph states by cavity quantum electrodynamics (QED). Our schemes require only the atom-cavity interaction with a large detuning which is available in current experiment so that these schemes are within the reach of the current technology

  8. Feasible schemes for preparation of all five-atom graph states

    Institute of Scientific and Technical Information of China (English)

    Zhang Jin

    2008-01-01

    We propose feasible schemes for preparation of all five-atom graph states by cavity quantum electrodynamics (QED). Our schemes require only the atom-cavity interaction with a large dettming which is available in current experiment so that these schemes axe within the reach of the current technology.

  9. IMRT in oral cavity cancer

    International Nuclear Information System (INIS)

    Except for early T1,2 N0 stages, the prognosis for patients with oral cavity cancer (OCC) is reported to be worse than for carcinoma in other sites of the head and neck (HNC). The aim of this work was to assess disease outcome in OCC following IMRT. Between January 2002 and January 2007, 346 HNC patients have been treated with curative intensity modulated radiation therapy (IMRT) at the Department of Radiation Oncology, University Hospital Zurich. Fifty eight of these (16%) were referred for postoperative (28) or definitive (30) radiation therapy of OCC. 40 of the 58 OCC patients (69%) presented with locally advanced T3/4 or recurred lesions. Doses between 60 and 70 Gy were applied, combined with simultaneous cisplatin based chemotherapy in 78%. Outcome analyses were performed using Kaplan Meier curves. In addition, comparisons were performed between this IMRT OCC cohort and historic in-house cohorts of 33 conventionally irradiated (3DCRT) and 30 surgery only patients treated over the last 10 years. OCC patients treated with postoperative IMRT showed the highest local control (LC) rate of all assessed treatment sequence subgroups (92% LC at 2 years). Historic postoperative 3DCRT patients and patients treated with surgery alone reached LC rates of ~70–80%. Definitively irradiated patients revealed poorest LC rates with ~30 and 40% following 3DCRT and IMRT, respectively. T1 stage resulted in an expectedly significantly higher LC rate (95%, n = 19, p < 0.05) than T2-4 and recurred stages (LC ~50–60%, n = 102). Analyses according to the diagnosis revealed significantly lower LC in OCC following definitive IMRT than that in pharyngeal tumors treated with definitive IMRT in the same time period (43% vs 82% at 2 years, p < 0.0001), while the LC rate of OCC following postoperative IMRT was as high as in pharyngeal tumors treated with postoperative IMRT (>90% at 2 years). Postoperative IMRT of OCC resulted in the highest local control rate of the assessed treatment

  10. JLab SRF Cavity Fabrication Errors, Consequences and Lessons Learned

    Energy Technology Data Exchange (ETDEWEB)

    Frank Marhauser

    2011-09-01

    Today, elliptical superconducting RF (SRF) cavities are preferably made from deep-drawn niobium sheets as pursued at Jefferson Laboratory (JLab). The fabrication of a cavity incorporates various cavity cell machining, trimming and electron beam welding (EBW) steps as well as surface chemistry that add to forming errors creating geometrical deviations of the cavity shape from its design. An analysis of in-house built cavities over the last years revealed significant errors in cavity production. Past fabrication flaws are described and lessons learned applied successfully to the most recent in-house series production of multi-cell cavities.

  11. Superconducting RF Cavity Frequency and Field Distribution Sensitivity Simulation

    CERN Document Server

    An, Sun

    2005-01-01

    Frequency and electromagnetic field distribution sensitivity of a superconducting RF (SRF) cavity due to cavity's small deformation are the fundamental phyical paramethers in cavity and tuner design. At low temperature, the frequency sensitivity can be obtained by measuring prototype cavity, but it is not easy to test the filed distribution sensitivity. This paper presents and describes a simulation method combining ANSYS and SUPERFISH to calculate the cavity frequency and field distribution variation due to cavity's small deformation caused by mechanical force, radiation force, thermal expansion etc.. As an example, the simulation results of the frequency and field flatness sensitivity on the SNS cavities were confirmed by their test results.

  12. Superconducting drift-tube cavity development for the RIA driver

    International Nuclear Information System (INIS)

    This paper reports the design and development of two intermediate-velocity superconducting cavities and design of an associated cryomodule for the RIA driver linac. The two cavity types are a 115 MHz, βGEOM = 0.15 quarter-wave resonant (QWR) cavity, and a 173 MHz, βGEOM = 0.26 half-wave loaded cavity. Both cavities are well-corrected for dipole and quadrupole asymmetries in the accelerating field. The cryomodule is being designed to incorporate a separate vacuum system for cavity vacuum to provide a particulate-free environment for the superconducting cavities

  13. Efficient Characterization of Protein Cavities within Molecular Simulation Trajectories: trj_cavity.

    Science.gov (United States)

    Paramo, Teresa; East, Alexandra; Garzón, Diana; Ulmschneider, Martin B; Bond, Peter J

    2014-05-13

    Protein cavities and tunnels are critical in determining phenomena such as ligand binding, molecular transport, and enzyme catalysis. Molecular dynamics (MD) simulations enable the exploration of the flexibility and conformational plasticity of protein cavities, extending the information available from static experimental structures relevant to, for example, drug design. Here, we present a new tool (trj_cavity) implemented within the GROMACS ( www.gromacs.org ) framework for the rapid identification and characterization of cavities detected within MD trajectories. trj_cavity is optimized for usability and computational efficiency and is applicable to the time-dependent analysis of any cavity topology, and optional specialized descriptors can be used to characterize, for example, protein channels. Its novel grid-based algorithm performs an efficient neighbor search whose calculation time is linear with system size, and a comparison of performance with other widely used cavity analysis programs reveals an orders-of-magnitude improvement in the computational cost. To demonstrate its potential for revealing novel mechanistic insights, trj_cavity has been used to analyze long-time scale simulation trajectories for three diverse protein cavity systems. This has helped to reveal, respectively, the lipid binding mechanism in the deep hydrophobic cavity of a soluble mite-allergen protein, Der p 2; a means for shuttling carbohydrates between the surface-exposed substrate-binding and catalytic pockets of a multidomain, membrane-proximal pullulanase, PulA; and the structural basis for selectivity in the transmembrane pore of a voltage-gated sodium channel (NavMs), embedded within a lipid bilayer environment. trj_cavity is available for download under an open-source license ( http://sourceforge.net/projects/trjcavity ). A simplified, GROMACS-independent version may also be compiled. PMID:26580540

  14. Solution preparation

    International Nuclear Information System (INIS)

    Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results

  15. Dual-cavity basket promotes encapsulation in water in an allosteric fashion.

    Science.gov (United States)

    Chen, Shigui; Yamasaki, Makoto; Polen, Shane; Gallucci, Judith; Hadad, Christopher M; Badjić, Jovica D

    2015-09-30

    We prepared dual-cavity basket 1 to carry six (S)-alanine residues at the entrance of its two juxtaposed cavities (289 Å(3)). With the assistance of (1)H NMR spectroscopy and calorimetry, we found that 1 could trap a single molecule of 4 (K1 = 1.45 ± 0.40 × 10(4) M(-1), ITC), akin in size (241 Å(3)) and polar characteristics to nerve agent VX (289 Å(3)). The results of density functional theory calculations (DFT, M06-2X/6-31G*) and experiments ((1)H NMR spectroscopy) suggest that the negative homotropic allosterism arises from the guest forming C-H···π contacts with all three of the aromatic walls of the occupied basket's cavity. In response, the other cavity increases its size and turns rigid to prevent the formation of the ternary complex. A smaller guest 6 (180 Å(3)), akin in size and polar characteristics to soman (186 Å(3)), was also found to bind to dual-cavity 1, although giving both binary [1⊂6] and ternary [1⊂62] complexes (K1 = 7910 M(-1) and K2 = 2374 M(-1), (1)H NMR spectroscopy). In this case, the computational and experimental ((1)H NMR spectroscopy) results suggest that only two aromatic walls of the occupied basket's cavity form C-H···π contacts with the guest to render the singly occupied host flexible enough to undergo additional structural changes necessary for receiving another guest molecule. The structural adaptivity of dual-cavity baskets of type 1 is unique and important for designing multivalent hosts capable of effectively sequestering targeted guests in an allosteric manner to give stable supramolecular polymers. PMID:26348904

  16. Beam loading in magnicon deflection cavities

    Energy Technology Data Exchange (ETDEWEB)

    Hafizi, B. [ICARUS Research, Inc., Bethesda, MD (United States); Gold, S.H. [Naval Research Lab., Washington, DC (United States). Plasma Physics Div.

    1997-02-01

    The radio frequency (RF) source for the next linear collider (NLC) is required to generate a power of 1/2--1 GW per tube in a 200-ns pulse, or 100--200 J of energy in a pulse of up to a few {micro}s in duration, at a frequency of 10--20 GHz. A variety of RF sources are under investigation at the present time aimed at fulfilling the needs of the NLC. These include the X-band klystron, Gyroklystron, traveling-wave tube, harmonic convertor, chopper-driven traveling-wave tube, and magnicon. Here, analysis of the beam-deflection cavity interaction in a magnicon is presented and compared with experiment. For a driven cavity a dispersion relation is obtained wherein the interaction modifies the cold-cavity factor and the resonance frequency. In terms of a lumped-parameter equivalent circuit the interaction corresponds to a complex-values beam admittance Y{sub b} in parallel with the cavity admittance. The response of the gain cavities is modified by the same admittance. In a magnicon, Y{sub b} is a sensitive function of the solenoidal focusing magnetic field B{sub 0}, thus providing a convenient means of adjusting the cavity properties in experiments. When the relativistic gyrofrequency is twice the drive frequency, ImY{sub b} = 0 and the beam does not load the cavity. Analytical expressions of the variation of the detuning, instantaneous bandwidth (i.e., loaded quality factor) and gain with B{sub 0} are derived. Simulation results are presented to verify the linear analysis with ideal beams and to illustrate the modifications due to finite beam emittance. Results of the magnicon experiment at the Naval Research Laboratory are examined in the light of the analysis.

  17. Superconducting cavity material for the European XFEL

    Science.gov (United States)

    Singer, W.; Singer, X.; Brinkmann, A.; Iversen, J.; Matheisen, A.; Navitski, A.; Tamashevich, Y.; Michelato, P.; Monaco, L.

    2015-08-01

    Analysis of the strategy for superconducting cavity material procurement and quality management is done on the basis of the experience with the cavity production for the European x-ray free electron laser (EXFEL) facility. An adjustment of the material specification to EXFEL requirements, procurement of material, quality control (QC), documentation, and shipment to cavity producers have been worked out and carried out by DESY. A multistep process of qualification of the material suppliers included detailed material testing, single- and nine-cell cavity fabrication, and cryogenic radiofrequency tests. Production of about 25 000 semi-finished parts of high purity niobium and niobium-titanium alloy in a period of three years has been divided finally between companies Heraeus, Tokyo Denkai, Ningxia OTIC, and PLANSEE. Consideration of large-grain (LG) material as a possible option for the EXFEL has resulted in the production of one cryogenic module consisting of seven (out of eight) LG cavities. LG materials fulfilled the EXFEL requirements and showed even 25% to 30% higher unloaded quality factor. A possible shortage of the required quantity of LG material on the market led, however, to the choice of conventional fine-grain (FG) material. Eddy-current scanning (ECS) has been applied as an additional QC tool for the niobium sheets and contributed significantly to the material qualification and sorting. Two percent of the sheets have been rejected, which potentially could affect up to one-third of the cavities. The main imperfections and defects in the rejected sheets have been analyzed. Samples containing foreign material inclusions have been extracted from the sheets and electrochemically polished. Some inclusions remained even after 150 μm surface layer removal. Indications of foreign material inclusions have been found in the industrially fabricated and treated cavities and a deeper analysis of the defects has been performed.

  18. Nonprobabilistic teleportation of field state via cavity QED

    OpenAIRE

    De Carvalho, Carlos Renato; Guerra, Emerson S.; Jalbert, Ginette; Garreau, Jean Claude

    2007-01-01

    International audience In this article we discuss a teleportation scheme of coherent states of cavity field. The experimental realization proposed makes use of cavity quatum electrodynamics involving the interaction of Rydberg atoms with micromaser and Ramsey cavities. In our scheme the Ramsey cavities and the atoms play the role of auxiliary systems used to teleport the state from a micromaser cavity to another. We show that, even if the correct atomic detection fails in the first trials,...

  19. Availability of tree cavities in a sal forest of Nepal

    OpenAIRE

    Bhusal P; Czeszczewik D; Walankiewicz W; Churski M; Baral R; Lamichhane BR; Mikusinski G

    2016-01-01

    Tree cavities are important structural elements of forest ecosystem that host numerous birds, mammals and other cavity-dependent organisms. Pattern of cavity distribution in temperate and boreal forests are relatively well studied, yet little is known about cavities in tropical and subtropical forests. We compared cavity availability in relation to tree condition (living tree and snag), tree species and DBH class between two different sites in a subtropical deciduous sal forest in Nepal: the ...

  20. Superconducting RF cavity R&D for future accelerators

    OpenAIRE

    Ginsburg, C.M.

    2009-01-01

    High-beta superconducting radiofrequency (SRF) elliptical cavities are being developed for several accelerator projects including Project X, the European XFEL, and the International Linear Collider (ILC). Fermilab has recently established an extensive infrastructure for SRF cavity R&D for future accelerators, including cavity surface processing and testing and cavity assembly into cryomodules. Some highlights of the global effort in SRF R&D toward improving cavity performance, and Fermilab SR...

  1. The main linac cavity for Cornell's energy recovery linac: Cavity design through horizontal cryomodule prototype test

    International Nuclear Information System (INIS)

    Future particle accelerators will require continuous wave operation of SRF cavities capable of supporting high beam currents. An example of this is the Energy Recovery Linac (ERL) at Cornell University, a next generation light source designed to run high currents (100 mA) with a high bunch repetition rate (1.3 GHz). Obtaining the beam emittance necessary to meet design specification requires strong damping of higher-order modes that can lead to beam breakup. We discuss the optimization and verification of the accelerating cavity. Next we show that an ERL constructed from the optimized cavity geometry – including realistic shape errors – can support beam currents in excess of 300 mA while still maintaining beam stability. A niobium prototype 7-cell cavity was fabricated and tested in a horizontal cryomodule. We show that the prototype cavity exceeds quality factor and gradient specifications of 2×1010 at 16.2 MV/m at 1.8 K by 50%, reaching Q=(3.0±0.3)×1010. The prototype cavity also satisfies all design constraints and has a higher order mode spectrum consistent with the optimized shape geometry. At 1.6 K, the cavity set a record for quality factor of a multicell cavity installed in a horizontal cryomodule reaching Q=(6.1±0.6)×1010

  2. ANALYSIS OF THE SLOT HEATING OF THE COUPLED CAVITY LINAC CAVITY

    International Nuclear Information System (INIS)

    CCL cavities are figures of revolution about the beam axis. An automated tuning program sets up the geometry for a symmetric accelerating cavity and runs SUPERFISH [1] repetitively, varying the geometry to tune each cavity to the desired frequency for the electromagnetic fields. SUPERFISH [1] solves Maxwell's equations in 2-D. A large portion of the RF power (60-80%) applied to accelerate protons is a waste heat deposited on the inside of the copper cavity. This waste heat is removed most efficiently with water circulating through cooling passages. The waste heat needs to be removed in order to minimize thermal deformations and with it control the resonance of the cavities. A slot between the main cavity and coupled cavity receives additional heating that is not captured in the 2-D analysis. This heating causes deformation of the region and with it frequency shift. This paper covers the estimation of the slot heating and three-dimensional thermal and structural analysis of the CCL cavity

  3. Cavity cooling of free silicon nanoparticles in high-vacuum

    CERN Document Server

    Asenbaum, Peter; Nimmrichter, Stefan; Sezer, Ugur; Arndt, Markus

    2013-01-01

    Laser cooling has given a boost to atomic physics throughout the last thirty years since it allows one to prepare atoms in motional states which can only be described by quantum mechanics. Most methods, such as Doppler cooling, polarization gradient cooling or sub-recoil laser cooling rely, however, on a near-resonant and cyclic coupling between laser light and well-defined internal states. Although this feat has recently even been achieved for diatomic molecules, it is very hard for mesoscopic particles. It has been proposed that an external cavity may compensate for the lack of internal cycling transitions in dielectric objects and it may thus provide assistance in the cooling of their centre of mass state. Here, we demonstrate cavity cooling of the transverse kinetic energy of silicon nanoparticles propagating in genuine high-vacuum (< 10^8 mbar). We create and launch them with longitudinal velocities even down to v < 1 m/s using laser induced thermomechanical stress on a pristine silicon wafer. The ...

  4. Dissipated power measurements in the A0 SRF cavity system

    International Nuclear Information System (INIS)

    Fermilab operates a single TESLA 9-cell superconducting RF cavity in support of a photoelectron R and D beam line. Power going into the 1.8K cryogenic system via static heat leak and RF dissipation is measured from the rate of rise of the pressure in the helium bath. This paper describes the techniques used to determine the cryostat heat load and the RF performance of the cavity. A photo-injector has been constructed at Fermilab to produce a low-energy (14--18 MeV) electron beam with high charge per bunch (8 nC), short bunch length (1 mm RMS), and small transverse emittance (<20 mm mrad). The facility was used to commission a photo-cathode RF gun for the TESLA Test Facility (TTF) Linac at DESY. At present, the Fermilab machine is being used for R and D in bunch length compression and fast beam diagnostics; experiments in plasma wake field acceleration and channeling acceleration are in preparation

  5. Enhancing entanglement generation of two atoms in a cavity with white noise using classical driving fields

    Institute of Scientific and Technical Information of China (English)

    Jiansong Zhang; Aixi Chen

    2011-01-01

    We investigate the entanglement dynamics of a quantum system consisting of two two-level atoms in a cavity with classical driving fields in the presence of white noise. The cavity is initially prepared in the vacuum state. Generally, the entanglement of two atoms decreases with the intensity of the thermal fields and the coupling strength of the two-level atoms to the thermal fields. However, we find that the entanglement of the quantum system can be enhanced by adjusting the frequency and the strength of the classical driving fields in the presence of white noise.%@@ We investigate the entanglement dynamics of a quantum system consisting of two two-level atoms in a cavity with classical driving fields in the presence of white noise.The cavity is initially prepared in the vacuum state.Generally, the entanglement of two atoms decreases with the intensity of the thermal fields and the coupling 8trength of the two-level atoms to the thermal fields.However, we find that the entanglement of the quantum system can be enhanced by adjusting the frequency and the strength of the classical driving fields in the presence of white noise.

  6. Transferring of a Two-Mode Entangled State Between Two Cavities via Cavity QED

    Institute of Scientific and Technical Information of China (English)

    WU Tao; NI Zhi-Xiang; YE Liu

    2007-01-01

    We propose a scheme for transferring of a two-mode entanglement of zero- or one-photon entangled states between two cavities via atom-cavity field resonant interaction.In our proposal,in order to transfer the entangled state,we only need two identical two-level atoms and a two-mode cavity for receiving the teleported state.This scheme does not require Bell-state measurement and performing any transformations to reconstruct the initial state.And the transfer can occur with 100% success probability in a simple manner.And a network for transferring of a two-mode entangled state between cavities is suggested.This scheme can also be extended to transfer N-mode entangled state of cavity.

  7. Long Wave Infrared Cavity Enhanced Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Taubman, Matthew S.; Scott, David C.; Cannon, Bret D.; Myers, Tanya L.; Bonebrake, Christopher A.; Aker, Pam M.; Wojcik, Michael D.; Munley, John T.; Nguyen, Vinh T.; Schultz, John F.

    2004-10-01

    The principal goal of Pacific Northwest National Laboratory's (PNNL's) long wave infrared (LWIR) cavity enhanced sensor (CES) project is to explore ultra-sensitive spectroscopic techniques and apply them to the development of LWIR chemical sensors needed for detecting weapons proliferation. This includes detecting not only the weapons of mass destruction (WMDs) themselves, but also signatures of their production and/or detonation. The LWIR CES project is concerned exclusively with developing point sensors; other portions of PNNL's IR Sensors program address stand off detection. PNNL's LWIR CES research is distinguished from that done by others by the use quantum cascade lasers (QCLs) as the light source. QCLs are novel devices, and a significant fraction of our research has been devoted to developing the procedures and hardware required to implement them most effectively for chemical sensing. This report details the progress we have made on our LWIR CES sensor development. During FY02, PNNL investigated three LWIR CES implementations beginning with the easiest to implement, direct cavity-enhanced detection (simple CES), including a technique of intermediate difficulty, cavity-dithered phase-sensitive detection (FM recovery CES) through to the most complex technique, that of resonant sideband cavity-enhanced detection also known as noise-immune cavity-enhanced optical heterodyne molecular spectroscopy, or NICE-OHMS.

  8. Dispersive optomechanics: a membrane inside a cavity

    International Nuclear Information System (INIS)

    We present the results of theoretical and experimental studies of dispersively coupled (or 'membrane in the middle') optomechanical systems. We calculate the linear optical properties of a high finesse cavity containing a thin dielectric membrane. We focus on the cavity's transmission, reflection and finesse as a function of the membrane's position along the cavity axis and as a function of its optical loss. We compare these calculations with measurements and find excellent agreement in cavities with empty-cavity finesses in the range 104-105. The imaginary part of the membrane's index of refraction is found to be ∼10-4. We calculate the laser cooling performance of this system, with a particular focus on the less-intuitive regime in which photons 'tunnel' through the membrane on a timescale comparable to the membrane's period of oscillation. Lastly, we present calculations of quantum non-demolition measurements of the membrane's phonon number in the low signal-to-noise regime where the phonon lifetime is comparable to the QND readout time.

  9. A spherical cavity model for quadrupolar dielectrics.

    Science.gov (United States)

    Dimitrova, Iglika M; Slavchov, Radomir I; Ivanov, Tzanko; Mosbach, Sebastian

    2016-03-21

    The dielectric properties of a fluid composed of molecules possessing both dipole and quadrupole moments are studied based on a model of the Onsager type (molecule in the centre of a spherical cavity). The dielectric permittivity ε and the macroscopic quadrupole polarizability αQ of the fluid are related to the basic molecular characteristics (molecular dipole, polarizability, quadrupole, quadrupolarizability). The effect of αQ is to increase the reaction field, to bring forth reaction field gradient, to decrease the cavity field, and to bring forth cavity field gradient. The effects from the quadrupole terms are significant in the case of small cavity size in a non-polar liquid. The quadrupoles in the medium are shown to have a small but measurable effect on the dielectric permittivity of several liquids (Ar, Kr, Xe, CH4, N2, CO2, CS2, C6H6, H2O, CH3OH). The theory is used to calculate the macroscopic quadrupolarizabilities of these fluids as functions of pressure and temperature. The cavity radii are also determined for these liquids, and it is shown that they are functions of density only. This extension of Onsager's theory will be important for non-polar solutions (fuel, crude oil, liquid CO2), especially at increased pressures. PMID:27004882

  10. Spindle cell carcinoma of the nasal cavity

    Directory of Open Access Journals (Sweden)

    Mark D DeLacure

    2013-02-01

    Full Text Available Spindle cell carcinoma (SpCC is a unique variant of squamous cell carcinoma (SCC. SpCC confined to the nasal cavity is extremely rare, with only one case having been previously reported. We present a case report of nasal cavity SpCC and review the literature on this rare entity. A 29-year-old male presented with intermittent epistaxis from the left nasal cavity. On physical examination, the patient had an ulcerated mass in the left nasal vestibule and a biopsy showed a proliferation of spindle and epitheliod cells. The patient underwent wide local excision of the mass via a lateral alotomy approach and reconstruction with a composite conchal bowl skin and cartilage graft. Histologically, the mass had dyplastic squamous epithelium and spindle-shaped cells admixed with epitheliod cells. Immunohistochemistry was only positive for pancytokeratin AE1/AE3 and vimentin. Six months after surgery, the patient continues to have no evidence of disease. On literature review, only one previous case of SpCC confined to the nasal cavity was identified. We present a rare case of nasal cavity SpCC. No definite treatment protocol exists for this unique entity, but we believe that this tumor should primarily be treated with aggressive, wide local excision. Adjuvant radiation and/or chemotherapy have also been used anecdotally.

  11. CERN Developments for 704 MHz Superconducting Cavities

    CERN Document Server

    Capatina, O; Aviles Santillana, I; Arnau Izquierdo, G; Bonomi, R; Calatroni, S; Chambrillon, J; Gerigk, F; Garoby, R; Guinchard, M; Junginger, T; Malabaila, M; Marques Antunes Ferreira, L; Mikulas, S; Parma, V; Pillon, F; Renaglia, T; Schirm, K; Tardy, T; Therasse, M; Vacca, A; Valverde Alonso, N; Vande Craen, A

    2013-01-01

    The Superconducting Proton Linac (SPL) is an R&D effort coordinated by CERN in partnership with other international laboratories. It is aiming at developing key technologies for the construction of a multi-megawatt proton linac based on state-of-the-art RF superconducting technology, which would serve as a driver in new physics facilities for neutrinos and/or Radioactive Ion Beam (RIB). Amongst the main objectives of this R&D effort, is the development of 704 MHz bulk niobium beta=1 elliptical cavities, operating at 2 K with a maximum accelerating gradient of 25 MV/m, and the testing of a string of cavities integrated in a machine-type cryomodule. The cavity together with its helium tank had to be carefully designed in coherence with the innovative design of the cryomodule. New fabrication methods have also been explored. Five such niobium cavities and two copper cavities are in fabrication. The key design aspects are discussed, the results of the alternative fabrication methods presented and the stat...

  12. DISCHARGING MASTOID CAVITY: A CLINICAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Praveen Kumar

    2015-05-01

    Full Text Available CONTEXT: A discharging mastoid cavity is a frustrating condition for both patient and surgeon and can occur after a canal wall down mastoidectomy operation . AIMS: To determine the percentage of patients having a discharging mastoid cavity and to establish the aetiological factors responsible for it . SETTING: Academic tertiary care referral institution . DESIGN: Prospective study MATERIALS AND METHODS: One hundred and sixty nine patie nts with chronic suppurative otitis media with cholesteatoma who underwent a canal wall down mastoidectomy were included in the study . These patients were regularly followed up to detect the occurrence of discharging mastoid cavity . RESULTS: Forty one ( 24 . 26% patients had a discharging mastoid cavity after a mean follow up of 4 . 2 years . The main causes were tympanic membrane perforation with exposed middle ear mucosa and open eustachian tube in thirty two patients ( 78 . 04% , followed by meatal stenosis in twenty five patients ( 60 . 97% and high facial ridge in twenty patients ( 48 . 78% . CONCLUSIONS: Tympanic membrane perforation with exposure of middle ear mucosa , meatal stenosis and a high facial ridge are important causes for a discharging mastoid cavity .

  13. Unifying Brillouin scattering and cavity optomechanics

    Science.gov (United States)

    Van Laer, Raphaël; Baets, Roel; Van Thourhout, Dries

    2016-05-01

    So far, Brillouin scattering and cavity optomechanics have been mostly disconnected branches of research, although both deal with photon-phonon coupling. This begs for the development of a broader theory that contains both fields. Here, we derive the dynamics of optomechanical cavities from that of Brillouin-active waveguides. This explicit transition elucidates the link between phenomena such as Brillouin amplification and electromagnetically induced transparency. It proves that effects familiar from cavity optomechanics all have traveling-wave partners, but not vice versa. We reveal a close connection between two parameters of central importance in these fields: the Brillouin gain coefficient and the zero-point optomechanical coupling rate. This enables comparisons between systems as diverse as ultracold atom clouds, plasmonic Raman cavities, and nanoscale silicon waveguides. In addition, back-of-the-envelope calculations show that unobserved effects, such as photon-assisted amplification of traveling phonons, are now accessible in existing systems. Finally, we formulate both circuit- and cavity-oriented optomechanics in terms of vacuum coupling rates, cooperativities, and gain coefficients, thus reflecting the similarities in the underlying physics.

  14. CT findings of malignant nasal cavity tumors

    International Nuclear Information System (INIS)

    To evaluate the CT findings of malignant nasal cavity tumors. Retrospective analysis was performed on 20 patients with pathologically-proven malignant nasal cavity tumors. Using CT, we analysed their location, extent of bone destruction and of involvement of adjacent structures, and enhancing pattern. A total of 20 cases included nine squamous cell carcinomas, three olfactory neuroblastomas, three lymphomas, two polymorphic reticulosis, one adenoid cystic carcinoma, one undifferentiated carcinoma and one metastasis from renal cell carcinoma. All cases except one adenoid cystic carcinoma and one squamous cell carcinoma revealed bone destruction or erosion. Aggressive bone destruction and irregular enhancement were seen in eight cases of squamous cell carcinoma, seven cases of which showed involvement of the adjacent paranasal sinuses, nasopharynx, and orbit. Olfactory neuroblastomas were centered in the superior nasal cavity and the adjacent ethmoid sinus, and erosion or destruction of the cribriform plate had occurred. Lymphomas showed bilateral involvement, with uniform contrast enhancement. Polymorphic reticuloses showed perforation or erosion of the nasal septum, with bilateral involvement of the nasal cavity. The location, presence of bone destruction, involvement of adjacent structures, and enhancement pattern of tumor on CT can be helpful for the differential diagnosis of malignant nasal cavity tumors

  15. Impact of nitrogen doping of niobium superconducting cavities on the sensitivity of surface resistance to trapped magnetic flux

    Science.gov (United States)

    Gonnella, Dan; Kaufman, John; Liepe, Matthias

    2016-02-01

    Future particle accelerators such as the SLAC "Linac Coherent Light Source-II" (LCLS-II) and the proposed Cornell Energy Recovery Linac require hundreds of superconducting radio-frequency (SRF) niobium cavities operating in continuous wave mode. In order to achieve economic feasibility of projects such as these, the cavities must achieve a very high intrinsic quality factor (Q0) to keep cryogenic losses within feasible limits. To reach these high Q0's in the case of LCLS-II, nitrogen-doping of niobium cavities has been selected as the cavity preparation technique. When dealing with Q0's greater than 1 × 1010, the effects of ambient magnetic field on Q0 become significant. Here, we show that the sensitivity to RF losses from trapped magnetic field in a cavity's walls is strongly dependent on the cavity preparation. Specifically, standard electropolished and 120 °C baked cavities show a sensitivity of residual resistance from trapped magnetic flux of ˜0.6 and ˜0.8 nΩ/mG trapped, respectively, while nitrogen-doped cavities show a higher sensitivity of residual resistance from trapped magnetic flux of ˜1 to 5 nΩ/mG trapped. We show that this difference in sensitivities is directly related to the mean free path of the RF surface layer of the niobium: shorter mean free paths lead to less sensitivity of residual resistance to trapped magnetic flux in the dirty limit (ℓ ≪ ξ0), while longer mean free paths lead to lower sensitivity of residual resistance to trapped magnetic flux in the clean limit (ℓ ≫ ξ0). These experimental results are also shown to have good agreement with recent theoretical predictions for pinned vortex lines oscillating in RF fields.

  16. Probing anharmonicity of a quantum oscillator in an optomechanical cavity

    Science.gov (United States)

    Latmiral, Ludovico; Armata, Federico; Genoni, Marco G.; Pikovski, Igor; Kim, M. S.

    2016-05-01

    We present a way of measuring with high precision the anharmonicity of a quantum oscillator coupled to an optical field via radiation pressure. Our protocol uses a sequence of pulsed interactions to perform a loop in the phase space of the mechanical oscillator, which is prepared in a thermal state. We show how the optical field acquires a phase depending on the anharmonicity. Remarkably, one only needs small initial cooling of the mechanical motion to probe even small anharmonicities. Finally, by applying tools from quantum estimation theory, we calculate the ultimate bound on the estimation precision posed by quantum mechanics and compare it with the precision obtainable with feasible measurements such as homodyne and heterodyne detection on the cavity field. In particular we demonstrate that homodyne detection is nearly optimal in the limit of a large number of photons of the field and we discuss the estimation precision of small anharmonicities in terms of its signal-to-noise ratio.

  17. Observing different quantum trajectories in cavity QED

    CERN Document Server

    Santos, Marcelo França

    2011-01-01

    The experimental observation of quantum jumps is an example of single open quantum systems that, when monitored, evolve in terms of stochastic trajectories conditioned on measurements results. Here we present a proposal that allows the experimental observation of a much larger class of quantum trajectories in cavity QED systems. In particular, our scheme allows for the monitoring of engineered thermal baths that are crucial for recent proposals for probing entanglement decay and also for entanglement protection. The scheme relies on the interaction of a three-level atom and a cavity mode that interchangeably play the roles of system and probe. If the atom is detected the evolution of the cavity fields follows quantum trajectories and vice-versa.

  18. Dynamically Reconfigurable Photonic Crystal Nanobeam Cavities

    CERN Document Server

    Frank, Ian W; McCutcheon, Murray W; Loncar, Marko

    2009-01-01

    Wavelength-scale, high Q-factor photonic crystal cavities have emerged as a platform of choice for on-chip manipulation of optical signals, with applications ranging from low-power optical signal processing and cavity quantum electrodynamics, to biochemical sensing. Many of these applications, however, are limited by the fabrication tolerances and the inability to precisely control the resonant wavelength of fabricated structures. Various techniques for post-fabrication wavelength trimming and dynamical wavelength control -- using, for example, thermal effects, free carrier injection, low temperature gas condensation, and immersion in fluids -- have been explored. However, these methods are often limited by small tuning ranges, high power consumption, or the inability to tune continuously or reversibly. In this letter, by combining nano-electro-mechanical systems (NEMS) and nanophotonics, we demonstrate reconfigurable photonic crystal nanobeam cavities that can be continuously and dynamically tuned using elec...

  19. CEBAF cavity fabrication - a successful technology transfer

    International Nuclear Information System (INIS)

    Babcock ampersand Wilcox (B ampersand W) has successfully completed an R.F. accelerator technology transfer with Cornell University for CEBAF, the Continuous Electron Beam Accelerator Facility. With this transfer of technology, B ampersand W has commercially fabricated four niobium LE-5 R.F. cavities, 12 niobium spool pieces, and 12 niobium adaptors for CEBAF. The fourth niobium cavity was warm tuned to specification at the B ampersand W test facility. The industrialization of the accelerator technology benefits the scientific community because industry can provide large scale production resources, including standardized procedures, processes, and specifications, to assist in the construction of accelerator/collider projects. B ampersand W has taken laboratory technology and developed standardized industrial procedures and processes for the fabrication of the CEBAF/Cornell R.F. cavity. B ampersand W's industrialization of accelerator technology is discussed herein. 5 refs., 1 fig

  20. Plasmonic coaxial waveguide-cavity devices.

    Science.gov (United States)

    Mahigir, Amirreza; Dastmalchi, Pouya; Shin, Wonseok; Fan, Shanhui; Veronis, Georgios

    2015-08-10

    We theoretically investigate three-dimensional plasmonic waveguide-cavity structures, built by side-coupling stub resonators that consist of plasmonic coaxial waveguides of finite length, to a plasmonic coaxial waveguide. The resonators are terminated either in a short or an open circuit. We show that the properties of these waveguide-cavity systems can be accurately described using a single-mode scattering matrix theory. We also show that, with proper choice of their design parameters, three-dimensional plasmonic coaxial waveguide-cavity devices and two-dimensional metal-dielectric-metal devices can have nearly identical transmission spectra. Thus, three-dimensional plasmonic coaxial waveguides offer a platform for practical implementation of two-dimensional metal-dielectric-metal device designs. PMID:26367907

  1. Nitrogen doping study in ingot niobium cavities

    Energy Technology Data Exchange (ETDEWEB)

    Dhakal, Pashupati [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Ciovati, Gianluigi [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Kneisel, Peter [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Myneni, Ganapati Rao [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Makita, Junki [Old Dominion Univ., Norfolk, VA (United States)

    2015-09-01

    Thermal diffusion of nitrogen in niobium superconducting radio frequency cavities at temperature ~800 °C has resulted in the increase in quality factor with a low-field Q-rise extending to Bp > 90 mT. However, the maximum accelerating gradient of these doped cavities often deteriorates below the values achieved by standard treatments prior to doping. Here, we present the results of the measurements on ingot niobium cavities doped with nitrogen at 800 °C. The rf measurements were carried out after the successive electropolishing to remove small amount of material from the inner surface layer. The result showed higher breakdown field with lower quality factor as material removal increases.

  2. Minimum wakefield achievable by waveguide damped cavity

    International Nuclear Information System (INIS)

    The authors use an equivalent circuit to model a waveguide damped cavity. Both exponentially damped and persistent (decay t-3/2) components of the wakefield are derived from this model. The result shows that for a cavity with resonant frequency a fixed interval above waveguide cutoff, the persistent wakefield amplitude is inversely proportional to the external Q value of the damped mode. The competition of the two terms results in an optimal Q value, which gives a minimum wakefield as a function of the distance behind the source particle. The minimum wakefield increases when the resonant frequency approaches the waveguide cutoff. The results agree very well with computer simulation on a real cavity-waveguide system

  3. Enhancements to cavity quantum electrodynamics system

    CERN Document Server

    Cimmarusti, A D; Norris, D G; Orozco, L A

    2011-01-01

    We show the planned upgrade of a cavity QED experimental apparatus. The system consists of an optical cavity and an ensemble of ultracold $^{85}$Rb atoms coupled to its mode. We propose enhancements to both. First, we document the building process for a new cavity, with a planned finesse of $\\sim$20000. We address problems of maintaining mirror integrity during mounting and improving vibration isolation. Second, we propose improvements to the cold atom source in order to achieve better optical pumping and control over the flux of atoms. We consider a 2-D optical molasses for atomic beam deflection, and show computer simulation results for evaluating the design. We also examine the possibility of all-optical atomic beam focusing, but find that it requires unreasonable experimental parameters.

  4. Observing spin optodynamical analog of cavity optomechanics

    Science.gov (United States)

    Gerber, Justin; Kohler, Jonathan; Spethmann, Nicolas; Schreppler, Sydney; Stamper-Kurn, Dan

    2016-05-01

    Cavity Optomechanics has been realized in many diverse systems and led to many interesting results such as ponderomotive squeezing of light, beyond-SQL measurement sensitivity, and squeezing of mechanical oscillators. Optical cavities also allow sensitive measurements of the spin of an atomic ensemble. It has been proposed to utilize this sensitivity to realize an analog of optomechanics by measuring the precession of small excitations of a spin-oscillator around a transverse magnetic field. I will present our recent work in which we realize optomechanical analogs in our system such as cavity-assisted cooling and amplification and optical spring shifts. In addition, the presence of a high-energy `ground state' of the spin oscillator allows the realization of an effective negative mass oscillator which is demonstrated by an inverted sideband asymmetry. In our ongoing work we attempt to realize coherent quantum noise cancelation by coupling spin oscillation with mechanical oscillation.

  5. High brightness angled cavity quantum cascade lasers

    International Nuclear Information System (INIS)

    A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh brightness value of 156 MW cm−2 sr−1 is obtained, which marks the brightest QCL to date

  6. Beam cavity interaction computer code for linacs

    International Nuclear Information System (INIS)

    A computer code BCI was used to calculate the energy loss of beam bunches in two types of cavities being studied in ORNL. The merit of the proposed on-axis coupled structure for CHEER is discussed in terms of beam energy loss. A calculation for a simple structure consisting of two accelerating cells and a coupling cell is performed. The amplitude modulation of the wake field is interpreted as the excitation of the zero and π coupled-resonator modes and coupling coefficients are derived. Beam loading of a cw linear accelerator is studied by calculating the bunch energy loss and cavity energy when a cavity is excited resonantly with a series of beam bunches. Calculations of non-resonant excitation are also presented

  7. Cryogenic system for TRISTAN superconducting RF cavity

    International Nuclear Information System (INIS)

    Superconducting RF cavities will be installed in TRISTAN at KEK to upgrade the electron-positron beam energy to 33 GeV x 33 GeV. Two 5-cell cavities are coupled together, enclosed in a cryostat, and cooled by liquid helium pool boiling. The cryogenic system for the cavities is described and a system flow diagram constructed. Heat loads are estimated and component specifications are given. The capacity of the helium refrigerator is 4 kW at 4.4 K with liquid nitrogen precooling and two expansion turbines. The system is designed to be upgraded to 6.5 kW with added expansion turbines and compressors and the elimination of liquid nitrogen

  8. TM01 mode accelerating cavity optimization

    International Nuclear Information System (INIS)

    The cost of an accelerator depends greatly upon the effective use of rf power for particle acceleration. Before completing an accelerator design, an optimization of the accelerating cells relative to the effective shunt impedance should be made to measure the structure's efficiency in providing a high and effective acceleration of particles for a given rf power. Optimization of the accelerating cell resonant at f/sub r/ = 1350 MHz (TM01 mode) relative to the maximum effective shunt impedance ZT2 was performed at the Los Alamos Scientific Laboratory using the computer program SUPERFISH. The study was parametric; one parameter was changed while the others were held constant. Frequency adjustments were made by changing the cavity radius. Results presented in this report can be used to design similar cavities at different resonant frequencies or to design a more complicated cavity (TM02 mode) for the disk and washer structure

  9. Crab cavity for the B-factories

    International Nuclear Information System (INIS)

    In order to realize the crab crossing scheme desired for B-factories, we have designed single cell superconducting crab cavities operating in TMI 10 mode. A coaxial beam pipe was attached to damp dangerous monopole and dipole parasitic modes. We designed two kinds of cell shape depending on the method to cure the unwanted polarization of TMI 10 mode; one is a round cell which will be slightly polarized and the other is an extremely polarized (squashed) cell. Necessary kick voltage can be obtained with the present technology of superconducting cavities. We have measured the coaxial beam pipe and a squashed crab cavity of one-third scale copper/aluminum model. The Q of all the dangerous monopole and dipole modes are damped to less than the order of 100, as was expected by calculations. High Q of the crabbing mode is also assured with a notch filter

  10. Cover slip external cavity diode laser

    CERN Document Server

    Carr, Adra V; Waitukaitis, Scott R; Perreault, John D; Lonij, Vincent P A; Cronin, Alexander D

    2007-01-01

    The design of a 671 nm diode laser with a mode-hop-free tuning range of 40 GHz is described. This long tuning range is achieved by simultaneously ramping the external cavity length with the laser injection current. The external cavity consists of a microscope cover slip mounted on piezoelectric actuators. In such a configuration the laser output pointing remains fixed, independent of its frequency. Using a diode with an output power of 5-7 mW, the laser linewidth was found to be smaller than 30 MHz. This cover slip cavity and feedforward laser current control system is simple, economical, robust, and easy to use for spectroscopy, as we demonstrate with lithium vapor and lithium atom beam experiments.

  11. High brightness angled cavity quantum cascade lasers

    Energy Technology Data Exchange (ETDEWEB)

    Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M., E-mail: razeghi@eecs.northwestern.edu [Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, Illinois 60208 (United States)

    2015-03-02

    A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh brightness value of 156 MW cm{sup −2 }sr{sup −1} is obtained, which marks the brightest QCL to date.

  12. Coaxial cavity vircator with enhanced efficiency

    Science.gov (United States)

    Liu, G. Z.; Shao, H.; Yang, Z. F.; Song, Z. M.; Chen, C. H.; Sun, J.; Zhang, Y. P.

    2008-04-01

    A vircator with a coaxial cavity has the potential to increase the beam-microwave conversion efficiency. According to the E-field distribution pattern of the modes in the anode cavity of a coaxial vircator, the resonant frequency band of the injected electron beam and the lowest two operating modes are derived. The main frequency of the virtual cathode is also deduced. The optimal operating frequency and high-efficiency designing method of a coaxial cavity vircator is discussed. An experimental setup is designed and built to test the high-power microwave (HPM) generation mechanism described by theoretical analysis as well as increase the power efficiency. HPM frequency obtained in the experiment is in good agreement with the analysis. The power and energy efficiencies obtained in the experiment are, respectively, 8.7% and 6.8% with 50 ns pulse width. Frequency and phase stable HPM radiation is observed as well as pulse shortening is evidently depressed.

  13. Prominence mass supply and the cavity

    International Nuclear Information System (INIS)

    A prevalent but untested paradigm is often used to describe the prominence-cavity system: the cavity is under-dense because it is evacuated by supplying mass to the condensed prominence. The thermal non-equilibrium (TNE) model of prominence formation offers a theoretical framework to predict the thermodynamic evolution of the prominence and the surrounding corona. We examine the evidence for a prominence-cavity connection by comparing the TNE model with diagnostics of dynamic extreme ultraviolet (EUV) emission surrounding the prominence, specifically prominence horns. Horns are correlated extensions of prominence plasma and coronal plasma which appear to connect the prominence and cavity. The TNE model predicts that large-scale brightenings will occur in the Solar Dynamics Observatory Atmospheric Imaging Assembly 171 Å bandpass near the prominence that are associated with the cooling phase of condensation formation. In our simulations, variations in the magnitude of footpoint heating lead to variations in the duration, spatial scale, and temporal offset between emission enhancements in the other EUV bandpasses. While these predictions match well a subset of the horn observations, the range of variations in the observed structures is not captured by the model. We discuss the implications of our one-dimensional loop simulations for the three-dimensional time-averaged equilibrium in the prominence and the cavity. Evidence suggests that horns are likely caused by condensing prominence plasma, but the larger question of whether this process produces a density-depleted cavity requires a more tightly constrained model of heating and better knowledge of the associated magnetic structure.

  14. Electrostatically tunable optomechanical "zipper" cavity laser

    CERN Document Server

    Perahia, Raviv; Meenehan, Sean; Alegre, Thiago P Mayer; Painter, Oskar

    2010-01-01

    A tunable nanoscale "zipper" laser cavity, formed from two doubly clamped photonic crystal nanobeams, is demonstrated. Pulsed, room temperature, optically pumped lasing action at a wavelength of 1.3 micron is observed for cavities formed in a thin membrane containing InAsP/GaInAsP quantum-wells. Metal electrodes are deposited on the ends of the nanobeams to allow for micro-electro-mechanical actuation. Electrostatic tuning and modulation of the laser wavelength is demonstrated at a rate of 0.25nm/V^2 and a frequency as high as 6.7MHz, respectively.

  15. Progress in diagnostic techniques for sc cavities

    International Nuclear Information System (INIS)

    While routinely achieved performance characteristics of superconducting cavities have now reached a level which makes them useful in large scale applications, achieving this level has come only through the knowledge gained by systematic studies of performance limiting phenomena. Despite the very real progress that has been made, the routine performance of superconducting cavities still falls far short of both the theoretical expectations and the performance of a few exception examples. It is the task of systematically applied diagnostic techniques to reveal additional information concerning the response of superconducting surfaces to applied RF fields. Here recent developments in diagnostic techniques are discussed. 18 references, 12 figures

  16. Short-cavity squeezing in barium

    Science.gov (United States)

    Hope, D. M.; Bachor, H-A.; Manson, P. J.; Mcclelland, D. E.

    1992-01-01

    Broadband phase sensitive noise and squeezing were experimentally observed in a system of barium atoms interacting with a single mode of a short optical cavity. Squeezing of 13 +/- 3 percent was observed. A maximum possible squeezing of 45 +/- 8 percent could be inferred for out experimental conditions, after correction for measured loss factors. Noise reductions below the quantum limit were found over a range of detection frequencies 60-170 MHz and were best for high cavity transmission and large optical depths. The amount of squeezing observed is consistent with theoretical predictions from a full quantum statistical model of the system.

  17. Optical cavity resonator in an expanding universe

    Science.gov (United States)

    Kopeikin, Sergei M.

    2015-02-01

    We study the cosmological evolution of frequency of a standing electromagnetic wave in a resonant optical cavity placed to the expanding manifold described by the Robertson-Walker metric. Because of the Einstein principle of equivalence (EEP), one can find a local coordinate system (a local freely falling frame), in which spacetime is locally Minkowskian. However, due to the conformal nature of the Robertson-Walker metric the conventional transformation to the local inertial coordinates introduces ambiguity in the physical interpretation of the local time coordinate, . Therefore, contrary to a common-sense expectation, a straightforward implementation of EEP alone does not allow us to unambiguously decide whether atomic clocks based on quantum transitions of atoms, ticks at the same rate as the clocks based on electromagnetic modes of a cavity. To resolve this ambiguity we have to analyse the cavity rigidity and the oscillation of its electromagnetic modes in an expanding universe by employing the full machinery of the Maxwell equations irrespectively of the underlying theory of gravity. We proceed in this way and found out that the size of the cavity and the electromagnetic frequency experience an adiabatic drift in conformal (unphysical) coordinates as the universe expands in accordance with the Hubble law. We set up the oscillation equation for the resonant electromagnetic modes, solve it by the WKB approximation, and reduce the coordinate-dependent quantities to their counterparts measured by a local observer who counts time with atomic clock. The solution shows that there is a perfect mutual cancellation of the adiabatic drift of cavity's frequency by space transformation to local coordinates and the time counted by the clocks based on electromagnetic modes of cavity has the same rate as that of atomic clocks. We conclude that if general relativity is correct and the local expansion of space is isotropic there should be no cosmological drift of frequency of a

  18. Fundamental Research in Superconducting RF Cavity Design

    Energy Technology Data Exchange (ETDEWEB)

    Georg Hoffstaetter

    2012-11-13

    This is a 3-year SRF R&D proposal with two main goals: 1) to benefit near term high gradient SRF applications by understanding the causes of quench at high fields in present-day niobium cavities 2) to open the long-range prospects for SRF applications by experimentally verifying the recent exciting theoretical predication for new cavity materials such as Nb3Sn and MgB2. These predictions shwo that ultimately gradients of 100Mv/m to 200MV/m may become possible as material imperfections are overcome.

  19. Cavity-induced quantum cooperative phenomena

    Science.gov (United States)

    Plastina, F.; Falcone, G.; Francica, F.; Liberti, G.; Piperno, F.; Maniscalco, S.

    2010-09-01

    Two kinds of cooperative effects are discussed for two-level atoms (qubits) interacting with an electromagnetic resonator, both of them concerning Dicke super-radiance. The first is a static, critical phenomenon: the so-called super-radiant phase transition, occurring when a large number of qubits are coupled to a single cavity mode giving rise to a quantum phase transition for a critical value of the interaction strength. The second is a dynamic phenomenon, producing (among other effects) the generation and/or preservation of entanglement between qubits even in the presence of cavity losses.

  20. Cavity-induced quantum cooperative phenomena

    International Nuclear Information System (INIS)

    Two kinds of cooperative effects are discussed for two-level atoms (qubits) interacting with an electromagnetic resonator, both of them concerning Dicke super-radiance. The first is a static, critical phenomenon: the so-called super-radiant phase transition, occurring when a large number of qubits are coupled to a single cavity mode giving rise to a quantum phase transition for a critical value of the interaction strength. The second is a dynamic phenomenon, producing (among other effects) the generation and/or preservation of entanglement between qubits even in the presence of cavity losses.