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1

Electron EDM Search with Trapped Molecular Ions  

Science.gov (United States)

A sample of trapped molecular ions offers unique possibilities to search for a permanent electron electric dipole moment (EDM). Specifically, we plan to perform this search using the unpaired electron spins in the ^3?1 state of trapped HfF^+ molecular ions. The ions will be confined in a linear RF Paul trap, allowing for long electron spin coherence times for increased sensitivity to an electron EDM. Effective internal fields of the molecular ions should exceed 10^10 V/cm, and the molecules are easily polarized in ˜ 1V/cm electric fields due to a small ? doubling splitting in the ^3?1 state. HfF^+ molecular ions are created via laser ablation of a Hafnium target in the presence of a He + 1%SF6 supersonic expansion. The expansion cools the ions rovibrational and translational temperatures to a few Kelvin. We will report current experimental progress.

Stutz, Russell; Loh, Huanqian; Sinclair, Laura; Cornell, Eric

2008-05-01

2

Observable Electron EDM and Leptogenesis  

CERN Multimedia

In the context of the minimal supersymmetric seesaw model, the CP-violating neutrino Yukawa couplings might induce an electron EDM. The same interactions may also be responsible for the generation of the observed baryon asymmetry of the Universe via leptogenesis. We identify in a model-independent way those patterns within the seesaw models which predict an electron EDM at a level probed by planned laboratory experiments and show that negative searches on \\tau-> e \\gamma decay may provide the strongest upper bound on the electron EDM. We also conclude that a possible future detection of the electron EDM is incompatible with thermal leptogenesis, even when flavour effects are accounted for.

Joaquim, F R; Riotto, Antonio

2007-01-01

3

Advanced cold molecule electron EDM  

Directory of Open Access Journals (Sweden)

Full Text Available Measurement of a non-zero electric dipole moment (EDM of the electron within a few orders of magnitude of the current best limit of |de| < 1.05 × 10?27?e?cm [1] would be an indication of physics beyond the Standard Model. The ACME Collaboration is searching for an electron EDM by performing a precision measurement of electron spin precession in the metastable H3?1 state of thorium monoxide (ThO using a slow, cryogenic beam. We discuss the current status of the experiment. Based on a data set acquired from 14 hours of running time over a period of 2 days, we have achieved a 1-sigma statistical uncertainty of ?de = 1 × 10?28?e?cm/?T, where T is the running time in days.

Campbell Wesley C.

2013-08-01

4

CKM benchmarks for electron EDM experiments  

CERN Document Server

All current experiments searching for an electron EDM d_e are performed with atoms and diatomic molecules. Motivated by significant recent progress in searches for an EDM-type signal in diatomic molecules with an uncompensated electron spin, we provide an estimate for the expected signal in the Standard Model due to the CKM phase. We find that the main contribution originates from the effective electron-nucleon operator $\\bar{e} i\\gamma_5 e \\bar{N}N$, induced by a combination of weak and electromagnetic interactions at $O(G_F^2\\alpha^2)$, and not by the CKM-induced electron EDM itself. When the resulting atomic P,T-odd mixing is interpreted as an {\\it equivalent} electron EDM, this estimate leads to the benchmark $d_e^{equiv}(CKM) \\sim 10^{-38}$ ecm.

Pospelov, Maxim

2013-01-01

5

Search for a permanent EDM using laser cooled radioactive atom  

Science.gov (United States)

The search for the electric-dipole moment (EDM) of laser-cooled francium (Fr) atoms could lead to a measurement for the electron EDM. It is predicted that the electron EDM would be enhanced by approximately three orders of magnitude in heavy atoms such as Fr. Laser-cooling and trapping techniques are expected to suppress statistical and systematic errors in precision measurements. The magneto-optical trap was achieved using stable rubidium in a developing factory of laser-cooled radioactive atoms. In light of the results from the rubidium experiments, we found that an upgrade of each apparatus is preferred for Fr trapping.

Kawamura, Hirokazu; Ando, S.; Aoki, T.; Arikawa, H.; Ezure, S.; Harada, K.; Hayamizu, T.; Inoue, T.; Ishikawa, T.; Itoh, M.; Kato, K.; Kato, T.; Nataraj, H. S.; Sato, T.; Uchiyama, A.; Aoki, T.; Furukawa, T.; Hatakeyama, A.; Hatanaka, K.; Imai, K.; Murakami, T.; Shimizu, Y.; Wakasa, T.; Yoshida, H. P.; Sakemi, Y.

2014-03-01

6

Progress of the Jila Electron Edm Experiment  

Science.gov (United States)

Molecules can be advantageous for the search for the electron electric dipole moment (eEDM) due to the large effective electric field experienced by a bound, unpaired electron. Furthermore, the closely-spaced states of opposite parity make the molecules easy to polarize in the lab frame. The JILA eEDM experiment currently uses HfF^+ molecules in an ion trap to achieve long coherence times to reduce systematics. When an electric field is applied the eEDM signal is proportional to the shift in energy splitting between two Zeeman levels in a low-lying, metastable ^3?_1 state. We have previously shown efficient preparation of trapped HfF^+ molecules in the rovibronic ground state, X^1?^+(v=0,J=0). Here, we demonstrate coherent transfer of population from the ground state to the a^3?_1(v=0, J=1) state through an intermediate ^3?_{0+} state and efficient state read-out using photodissociation. In addition, we have begun to take spectroscopy data of the hyperfine and Zeeman structure of the eEDM science state in the presence of a rotating bias electric field and a magnetic field. A. E. Leanhardt et. al., Journal of Molecular Spectroscopy 270, 1-25 (2011). H. Loh et. al., Journal of Chemical Physics 135, 154308 (2011).

Loh, Huanqian; Cossel, Kevin C.; Grau, Matt; Gresh, Daniel N.; Ni, Kang-Kuen; Ye, Jun; Cornell, Eric A.

2013-06-01

7

Towards the electron EDM search: Theoretical study of HfF+  

CERN Document Server

We report ab initio relativistic correlation calculations of potential curves for ten low-lying electronic states, effective electric field on the electron and hyperfine constants for the ^3\\Delta_1 state of the HfF^+ cation that is suggested to be used as the working state in experiments to search for the electric dipole moment of the electron. Calculations show that HfF^+ has deeply bound ^1\\Sigma^+ ground state, its dissociation energy is D_e=6.4 eV. The ^3\\Delta_1 state is obtained to be the first excited state lying about 0.2 eV higher. The calculated effective electric field E_eff=W_d|\\Omega| acting on an electron in this state is 5.84*10^{24}Hz/(e*cm)

Petrov, A N; Mosyagin, N S; Titov, A V

2006-01-01

8

Theoretical study of HfF$^+$ for the electron EDM search  

CERN Document Server

We report ab initio relativistic correlation calculations of potential curves and electric dipole transition moments for ten low-lying electronic states, effective electric field on the electron, hyperfine constants and radiative lifetimes for the $^3\\Delta_1$ state of cation of the heavy transition metal fluoride HfF$^+$, which it is suggested to be used in experiments to search for the electric dipole moment of the electron. It is obtained that HfF$^+$ has deeply bound $^1\\Sigma^+$ ground state; its dissociation energy is $D_e=6.4$ eV. The $^3\\Delta_1$ state is obtained as the relatively long-lived, with lifetime equal to about 0.4 s.,first excited state lying about 0.2 eV higher. The calculated effective electric field, $E_{eff}=W_d|\\Omega|$, acting on an electron in this state is $5.84*10^{24} Hz/{e*cm}$. The obtained hyperfine constants are $A_{\\parallel}= -1239$ MHz for the $^{177}$Hf nucleus and $A_{\\parallel}= -58.1$ MHz for the $^{19}$F nucleus.

Petrov, A N; Titov, A V

2008-01-01

9

Towards the electron EDM search. Theoretical study of PbF  

CERN Document Server

We report ab initio relativistic correlation calculations of potential curves and spectroscopic constants for four lowest-lying electronic states of the lead monofluoride. We also calculated parameters of the spin-rotational Hamiltonian for the ground and the first excited states including P,T-odd and P-odd terms. In particular, we have obtained hyperfine constants of the $^{207}$Pb nucleus. For the $^2\\Pi_{1/2}$ state $A_\\perp=-6859.6$ MHz, $A_\\|=9726.9$ MHz and for the A$^2\\Sigma^+_{1/2}$ $A_\\perp=1720.8$ MHz, $A_\\|=3073.3$ MHz. Our values of the ground state hyperfine constants are in good agreement with the previous theoretical studies. We discuss and explain seeming disagreement in the sign of the constant $A_\\perp$ with the recent experimental data. The effective electric field on the electron $E_{eff}$, which is important for the planned experiment to search for the electric dipole moment of the electron, is found to be 3.3 * 10^{10} V/cm.

Baklanov, K I; Titov, A V; Kozlov, M G

2010-01-01

10

Improved Measurement of the Electron EDM  

Science.gov (United States)

The electron is predicted to be slightly aspheric,ootnotetextI. B. Khriplovich, S. K. Lamoreaux, CP Violation Without Strangeness (Springer, New York, 1997). though no experiment has ever observed this deviation. Comparing the measured and predicted shape provides a powerful test of the standard model of particle physics. The shape is also intimately related to one of the largest outstanding questions in cosmology: why is the universe almost entirely devoid of antimatter? The electron's shape can be characterised by its electric dipole moment (EDM), de, which measures the deviation of its electric interactions from purely spherical. According to the standard model, this EDM is de 10-38 e.cm -- some eleven orders of magnitude below the current experimental limit. Most extensions to the standard model predict much larger values, potentially accessible to measurement.ootnotetextE. D. Commins, Electric dipole moments of leptons, in Advances in Atomic, Molecular, and Optical Physics, Vol. 40, B. Bederson and H.Walther (Eds.), Academic Press, New York, pp. 1-56 (1999). Hence, the search for the electron EDM is a search for physics beyond the standard model. Moreover, a non-zero breaks time-reversal symmetry which, in many models of particle physics, is equivalent to breaking the symmetry between matter and antimatter, known as CP symmetry. New CP-breaking physics is thought to be needed to explain the existence of a material universe.ootnotetextA. D. Sakharov, Violation of CP invariance, C asymmetry, and baryon asymmetry of the universe, Pis'ma ZhETF 5, 32 (1967). *Sov. Phys. JETP Lett. 5, 24 (1967).] We have used cold, polar molecules to measure the electron EDM, obtaining the result de= (-2.4 ±5.7stat±1.5syst) x10-28 e.cm. We set a new upper limit of with 90% confidence. Our result, consistent with zero, indicates that the electron is spherical at this improved level of precision. Our measurement, of atto-eV energy shifts in a molecule, probes new physics at the tera-eV energy scale. Many extensions to the standard model, such as the minimal supersymmetric standard model, naturally predict large EDMs and our measurement places significant constraints on the parameters of these theories.ootnotetextE. D. Commins and D. DeMille, ``The electric dipole moment of the electron,'' Chapter 14 in Lepton Dipole Moments Eds. B. L. Roberts and W. J. Marciano, (World Scientific, Singapore 2010).

Hinds, E. A.

2011-06-01

11

Magnetic Field Stabilization for 129Xe EDM Search Experiment  

Science.gov (United States)

Magnetic field stabilization is a crucial condition parameter for many kinds of ultra-high precision measurements such as a search for an electric dipole moment (EDM). The instability of magnetic field strength often arises from the drift of current flow in a solenoid coil to generate the magnetic field. For our EDM search experiment with maser oscillating diamagnetic 129Xe atoms, we have developed a new stabilized current source based on a feedback system which is devised to correct the amount of current flow measured precisely with high-precision digital multimeter and standard resistor. Using this new current source, we have successfully reduced the drifts of coil current by at least a factor of 100 compared to commercially available current sources.

Furukawa, Takeshi; Inoue, Takeshi; Nanao, Tsubasa; Yoshimi, Akihiro; Tsuchiya, Masato; Hayashi, Hironori; Uchida, Makoto; Asahi, Koichiro

2011-09-01

12

Magnetic Field Stabilization for 129Xe EDM Search Experiment  

International Nuclear Information System (INIS)

Magnetic field stabilization is a crucial condition parameter for many kinds of ultra-high precision measurements such as a search for an electric dipole moment (EDM). The instability of magnetic field strength often arises from the drift of current flow in a solenoid coil to generate the magnetic field. For our EDM search experiment with maser oscillating diamagnetic 129Xe atoms, we have developed a new stabilized current source based on a feedback system which is devised to correct the amount of current flow measured precisely with high-precision digital multimeter and standard resistor. Using this new current source, we have successfully reduced the drifts of coil current by at least a factor of 100 compared to commercially available current sources.

2011-09-23

13

Precursor Experiments to Search for Permanent Electric Dipole Moments (EDMs) of Protons and Deuterons at COSY  

CERN Document Server

In this presentation we discuss a number of experiments on the search for proton or deuteron EDMs, which could be carried out at COSY-Juelich. Most promising is the use of an radio-frequency radial electric field flipper that would lead to the accumulation of a CP violating in-plane beam polarization by tiny spin rotations. Most crucial for storage ring searches for EDMs is the spin-coherence time, and we report on analytic evaluations which point at a much larger spin-coherence time for deuterons by about a factor of 200 compared to the one for protons, and at COSY, the spin coherence time for deuterons could amount to about 10 000 s.

Lehrach, Andreas; Morse, William; Nikolaev, Nikolai; Rathmann, Frank

2012-01-01

14

Nuclear spin maser and experimental search for {sup 129}Xe atomic EDM  

Energy Technology Data Exchange (ETDEWEB)

The present status of an active spin maser which is being developed for an experimental search for {sup 129}Xe atomic electric dipole moment (EDM) is presented. In order to realize the long term stability of maser frequency, systematic effects for the spin maser operation were investigated. The correlations in the maser frequency with the solenoid current, the environmental field and the cell temperature were found. With the solenoid current and environmental field being stabilized and the cell temperature lowered, a frequency precision of 7.9 nHz has been achieved for the maser operation.

Inoue, T., E-mail: inoue_t@cyric.tohoku.ac.jp [Tohoku University, Cyclotron and Radioisotope Center (Japan); Furukawa, T. [Tokyo Metropolitan University, Department of Physics (Japan); Yoshimi, A. [Okayama University, Research Core for Extreme Quantum World (Japan); Ichikawa, Y.; Chikamori, M.; Ohtomo, Y.; Tsuchiya, M.; Yoshida, N.; Shirai, H.; Uchida, M.; Suzuki, K.; Nanao, T.; Miyatake, H. [Tokyo Institute of Technology, Department of Physics (Japan); Ueno, H.; Matsuo, Y. [RIKEN Nishina Center (Japan); Fukuyama, T. [Ritsumeikan University (Japan); Asahi, K. [Tokyo Institute of Technology, Department of Physics (Japan)

2013-05-15

15

Electron EDM as a Sensitive Probe of PeV Scale Physics  

CERN Document Server

We give a quantitative analysis of the electric dipole moments as a probe of high scale physics. We focus on the electric dipole moment of the electron since the limit on it is the most stringent. Further, theoretical computations of it are free of QCD uncertainties. The analysis presented here first explores the probe of high scales via electron EDM within MSSM where the contributions to the EDM arise from the chargino and the neutralino exchanges in loops. Here it is shown that the electron EDM can probe mass scales from tens of TeV into the PeV range.The analysis is then extended to include a vectorlike generation which can mix with the three ordinary generations. Here new CP phases arise and it is shown that the electron EDM now has not only a supersymmetric contribution from the exchange of charginos and neutralinos but also a non-supersymmetric contribution from the exchange of W and Z bosons. It is further shown that the interference of the supersymmetric and the non-supersymmetric contribution leads t...

Ibrahim, Tarek; Nath, Pran

2014-01-01

16

Neutron diffraction and optics in noncentrosymmetric crystals New feasibility of a search for neutron EDM  

International Nuclear Information System (INIS)

Recently strong electric fields (up to 109 V/cm) have been discovered, which affect the neutrons moving in noncentrosymmetric crystals. Such fields allow for new polarization phenomena in the neutron diffraction and in the optics and provide, for instance, a new method of a search for the neutron electric dipole moment (EDM). A strong interplanar electric field of the crystal and a sufficiently long time for the neutron passage through the crystal for Bragg angle close to ?/2 in the case of Laue diffraction make it possible to exceed the sensitivity achieved with the magnetic resonance method using ultra cold neutrons (UCN method). The pilot setup has been created and mounted at the neutron beam at the WWR-M reactor in Gatchina. It allows to study the optics and the dynamical diffraction of polarized neutrons in thick (1-10 cm) crystals, using the direct diffraction beam and Bragg angles close to 90 deg. . The first experimental results are discussed on observing new effects in both the Laue diffraction and the optics of cold neutrons. These results confirm the opportunity to increase more than by an order of magnitude the sensitivity of the method to neutron EDM, using the diffraction angles close to 90 deg. and give a real prospect to exceed the sensitivity of the UCN method

2003-01-01

17

Broadband Velocity Modulation Spectroscopy of Molecular Ions for Use in the Jila Electron Edm Experiment  

Science.gov (United States)

The JILA electron electric dipole moment (eEDM) experiment will use a low-lying, metastable ^3?_1 state in trapped molecular ions of HfF^+ or ThF^+. Prior to this work, the low-lying states of these molecules had been investigated by PFI-ZEKE spectroscopy. However, there were no detailed studies of the electronic structure. The recently developed technique of frequency comb velocity modulation spectroscopy (VMS) provides broad-bandwidth, high-resolution, ion-sensitive spectroscopy, allowing the acquisition of 150 cm^{-1} of continuous spectra in 30 minutes over 1500 simultaneous channels. By supplementing this technique with cw-laser VMS, we have investigated the electronic structure of HfF^+ in the frequency range of 9950 to 14600 cm^{-1}, accurately fitting and assigning 16 rovibronic transitions involving 8 different electronic states including the X^1?^+ and a^3?_1 states. In addition, an observed ^3?_{0+} state with coupling to both the X and a states has been used in the actual eEDM experiment to coherently transfer population from the rovibronic ground state of HfF^+ to the eEDM science state. Furthermore, we report on current efforts of applying frequency comb VMS at 700 - 900 nm to the study of ThF^+, which has a lower energy ^3?_1 state and a greater effective electric field, and will provide increased sensitivity for a measurement of the eEDM. A. E. Leanhardt et. al., Journal of Molecular Spectroscopy 270, 1-25 (2011). B. J. Barker, I. O. Antonov, M. C. Heaven, K. A. Peterson, Journal of Chemical Physics 136, 104305 (2012). L. C. Sinclair, K. C. Cossel, T. Coffey, J. Ye, E. A. Cornell, Physical Review Letters 107, 093002 (2011). K.C. Cossel et. al., Chemical Physics Letters 546, 1-11 (2012).

Gresh, Daniel N.; Cossel, Kevin C.; Cornell, Eric A.; Ye, Jun

2013-06-01

18

Fermion EDMs with Minimal Flavor Violation  

CERN Document Server

We study the electric dipole moments (EDMs) of fermions in the standard model supplemented with right-handed neutrinos and its extension including neutrino seesaw mechanism under the framework of minimal flavor violation (MFV). In the quark sector, we find that the current experimental bound on the neutron EDM does not yield a~significant restriction on the scale of MFV. In addition, we consider how MFV may affect the contribution of the strong theta-term to the neutron EDM. For the leptons, the existing EDM data also do not lead to strict limits if neutrinos are Dirac particles. On the other hand, if neutrinos are Majorana in nature, we find that the constraints become substantially stronger. Moreover, the results of the latest search for the electron EDM by the ACME Collaboration are sensitive to the MFV scale of order a~few hundred GeV or higher. We also look at constraints from $CP$-violating electron-nucleon interactions that may be probed in atomic or molecular EDM searches.

He, Xiao-Gang; Li, Siao-Fong; Tandean, Jusak

2014-01-01

19

The radon EDM apparatus  

Science.gov (United States)

The observation of a permanent electric dipole moment (EDM) at current experimentally accessible levels would provide clear evidence of physics beyond the Standard Model. EDMs violate CP symmetry, making them a possible route to explaining the size of the observed baryon asymmetry in the universe. The Radon EDM Experiment aims to search for an EDM in radon isotopes whose sensitivity to CP-odd interactions is enhanced by octupole-deformed nuclei. A prototype apparatus currently installed in the ISAC hall at TRIUMF includes a gas handling system to move radon from a collection foil to a measurement cell and auxiliary equipment for polarization diagnostics and validation. The features and capabilities of the apparatus are described and an overview of the experimental design for a gamma-ray-anisotropy based EDM measurement is provided.

Tardiff, E. R.; Rand, E. T.; Ball, G. C.; Chupp, T. E.; Garnsworthy, A. B.; Garrett, P.; Hayden, M. E.; Kierans, C. A.; Lorenzon, W.; Pearson, M. R.; Schaub, C.; Svensson, C. E.

2014-01-01

20

Electron electric-dipole-moment searches based on alkali-metal- or alkaline-earth-metal-bearing molecules  

International Nuclear Information System (INIS)

We introduce four new molecules - YbRb, YbCs, YbSr+, and YbBa+ - that may prove fruitful in experimental searches for the electric-dipole moment (EDM) of the electron. These molecules can, in principle, be prepared at extremely low temperatures by photoassociating ultracold atoms and therefore may present an advantage over molecular-beam experiments. Here we discuss properties of these molecules and assess the effective electric fields they contribute to an electron EDM measurement.

2009-10-01

 
 
 
 
21

Search for the neutron EDM by crystal-diffraction method. Test experiment and future progress  

Science.gov (United States)

Possible future progress of the crystal-diffraction neutron electric dipole moment search experiment is discussed. A storage modification of the experiment is proposed. It is demonstrated that sensitivity of the method can be a few 10 -27 e cm for the BSO crystal with the size 10×10×10 cm 3 and expected luminosity of European Spallation Source (ESS).

Fedorov, V. V.; Voronin, V. V.; Braginetz, Yu. P.

2011-06-01

22

A search for the electric dipole of the electron  

International Nuclear Information System (INIS)

We report a new upper limit on the electric dipole moment (EDM) of the electron of de = 0.1 ± 3.2 x 10-26 e-cm. This precision is one hundred times better than any previously published limit and a factor of two better than that of unofficial reports. Recently there has been a great deal of theoretical interest in the possibility of a non-zero electron EDM. Models such as the left-right-symmetric Standard Model and an ''off-standard'' model with new heavy neutrinos are constrained by the new limit on de. A non-zero electron EDM would violate the time reversal and parity space-time symmetries. T-violation was observed in neutral kaon decay and is still not fully explained by the Standard Model. Our experimental technique involves searching for an energy shift, linear in applied electric field, between the mF = 1 and mF = -1 magnetic sublevels of the F=1 hyperfine level of the 62P1/2 ground state of atomic thallium. If the electron has a non-zero EDM, this thallium state will exhibit an atomic electric dipole moment that is roughly 600 times larger. The energy shift is detected with the technique of magnetic resonance spectroscopy, employing separated oscillating fields, applied to an atomic beam of thallium. In the approach, any relative phase-shift between the mF = ±1 components of the F=1 wavefunction acquired by the atom as it travels through an electric field is detected through interference with two separate oscillating magnetic fields located on either side of the electric field. The new level of precision is achieved through several improvements on previous experiments including employment of a vertical apparatus, two opposing atomic beams, and optical pumping for atomic state selection and analysis

1989-01-01

23

Proof of principle for a high sensitivity search for the electric dipole moment of the electron using the metastable a(1)[^3\\Sigma^+] state of PbO  

CERN Document Server

The metastable a(1)[^3\\Sigma^+] state of PbO has been suggested as a suitable system in which to search for the electric dipole moment (EDM) of the electron. We report here the development of experimental techniques allowing high-sensitivity measurements of Zeeman and Stark effects in this system, similar to those required for an EDM search. We observe Zeeman quantum beats in fluorescence from a vapor cell, with shot-noise limited extraction of the quantum beat frequencies, high counting rates, and long coherence times. We argue that improvement in sensitvity to the electron EDM by at least two orders of magnitude appears possible using these techniques.

Kawall, D; Bickman, S R; Jiang, Y; De Mille, D P

2003-01-01

24

Proposal for a Sensitive Search for the Electric Dipole Moment of the Electron with Matrix-Isolated Radicals  

International Nuclear Information System (INIS)

We propose using matrix-isolated paramagnetic diatomic molecules to search for the electric dipole moment of the electron (eEDM). As was suggested by Shapiro in 1968, the eEDM leads to a magnetization of a sample in the external electric field. In a typical condensed matter experiment, the effective field on the unpaired electron is of the same order of magnitude as the laboratory field, typically about 105 V/cm. We exploit the fact that the effective electric field inside heavy polar molecules is on the order of 1010 V/cm. This leads to a huge enhancement of the Shapiro effect. Statistical sensitivity of the proposed experiment may allow one to improve the current limit on eEDM by 3 orders of magnitude in a few hours accumulation time

2006-08-11

25

Standard model extensions for PV electron scattering, g-2, EDM: Overview  

CERN Document Server

I review how various extensions of the Standard Model, in particular supersymmetry and extra neutral gauge bosons, may affect low energy observables, including parity-violating electron scattering and related observables, as well as electric and magnetic dipole moments.

Erler, Jens

2011-01-01

26

Current trends in searches for new physics using measurements of parity violation and electric dipole moments in atoms and molecules  

CERN Document Server

We review current status of the study of parity and time invariance phenomena in atoms, nuclei and molecules. We focus on three most promising areas of research: (i) parity non-conservation in a chain of isotopes, (ii) search for nuclear anapole moments, and (iii) search for permanent electric dipole moments (EDM) of atoms and molecules which are caused by either, electron EDM or nuclear $T,P$-odd moments such as nuclear EDM and nuclear Schiff moment.

Dzuba, V A

2010-01-01

27

Introducing the new EDMS  

CERN Multimedia

We are very pleased to announce the arrival of a brand new EDMS: EDMS 6. The CERN Engineering and Equipment Data Management Service just got better than ever! EDMS is the de facto interface for all engineering related data and more. Currently there are more than 1.2 million documents and nearly 2 million files stored in EDMS.   What’s new? The first thing you will notice is the look and feel of EDMS 6; the new design not only makes it more modern but also more intuitive, so that the system is easier to use, regardless of your experience with EDMS. Whilst we have kept the key concepts, we have introduced more functionality and improved navigation within the interface, allowing for better performance to help you in your daily work. We have also added a personal slant to EDMS 6 so that you can now customise your list of favourite objects. Modifying data in EDMS is much simpler, allowing you to view all object data in a single window.  More functionality will be added in the ...

The EDMS Team

2014-01-01

28

The Berkeley search for the electron electric dipole moment  

Energy Technology Data Exchange (ETDEWEB)

The status of the Berkeley measurement of the electron electric dipole moment is presented. The electron electric dipole moment can only be non-zero if the fundamental symmetries C and T are violated. To date, no non-vanishing dipole moment has been measured. Although the Standard Model predicts a value of d{sub e} {approx}10{sup -37} e cm, approximately ten orders of magnitude smaller than we can measure, extensions of the model predicts non-zero EDM`s easily within experimental reach. The basic elements of the experiment are described, the current expectations of machine performance are provided. (author). 4 refs., 3 figs.

Ross, S.B. [Max-Planck-Institut fuer Quantenoptik, Garching (Germany)

1994-12-31

29

The prospects for a new search for the electron electric dipole moment in solid Gadolinium iron garnet ceramics  

CERN Document Server

We address a number of issues regarding solid state electron electric dipole moment (EDM) experiments, focusing on gadolinium iron garnet (abbreviated GdIG, chemical formula Gd$_3$Fe$_5$O$_{12}$) as a possible sample material. GdIG maintains its high magnetic susceptibility down to 4.2 K, which enhances the EDM-induced magnetization of a sample placed in an electric field. We estimate that lattice polarizability gives rise to an EDM enhancement factor of approximately 20. We also calculate the effect of the demagnetizing field for various sample geometries and permeabilities. Measurements of intrinsic GdIG magnetization noise are presented, and the fluctuation-dissipation theorem is used to compare our data with the measurements of the imaginary part of GdIG permeability at 4.2 K, showing good agreement above frequencies of a few hertz. We also observe how the demagnetizing field suppresses the noise-induced magnetic flux, confirming our calculations. The statistical sensitivity of an EDM search based on a so...

Sushkov, A O; Lamoreaux, S K

2008-01-01

30

PLANS FOR A NEUTRON EDM EXPERIMENT AT SNS  

Energy Technology Data Exchange (ETDEWEB)

The electric dipole moment of the neutron, leptons, and atoms provide a unique window to Physics Beyond the Standard Model. They are currently developing a new neutron EDM experiment (the nEDM Experiment). This experiment, which will be run at the 8.9 {angstrom} Neutron Line at the Fundamental Neutron Physics Beamline (FNPB) at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory, will search for the neutron EDM with a sensitivity two orders of magnitude higher than the present limit. In this paper, the motivation for the experiment, the experimental method, and the present status of the experiment are discussed.

ITO, TAKEYASU [Los Alamos National Laboratory

2007-01-31

31

Communication: theoretical study of ThO for the electron electric dipole moment search.  

Science.gov (United States)

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H(3)?1 state of ThO molecule was proposed and now prepared by the ACME Collaboration [http://www.electronedm.org]. To interpret the experiment in terms of eEDM and dimensionless constant kT, P characterizing the strength of the T,P-odd pseudoscalar-scalar electron-nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, Eeff, and a parameter of the T,P-odd pseudoscalar-scalar interaction, WT, P, in ThO is required. We report our results for Eeff (84 GV/cm) and WT, P (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H(3)?1 ? X(1)?(+) transition energy, which can serve as a measure of reliability of the obtained Eeff and WT, P values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the ?-doublets of H(3)?1. PMID:24329049

Skripnikov, L V; Petrov, A N; Titov, A V

2013-12-14

32

EDMS based workflow for Printing Industry  

Directory of Open Access Journals (Sweden)

Full Text Available Information is indispensable factor of any enterprise. It can be a record or a document generated for every transaction that is made, which is either a paper based or in electronic format for future reference. A Printing Industry is one such industry in which managing information of various formats, with latest workflows and technologies, could be a nightmare and a challenge for any operator or an user when each process from the least bit of information to a printed product are always dependendent on each other. Hence the information has to be harmonized artistically in order to avoid production downtime or employees pointing fingers at each other. This paper analyses how the implementation of Electronic Document Management System (EDMS could contribute to the Printing Industry for immediate access to stored documents within and across departments irrespective of geographical boundaries. The paper outlines initially with a brief history, contemporary EDMS system and some illustrated examples with a study done by choosing Library as a pilot area for evaluating EDMS. The paper ends with an imitative proposal that maps several document management based activities for implementation of EDMS for a Printing Industry.

Prathap Nayak

2012-03-01

33

Progress towards an atomic EDM measurement of Ra-225  

Science.gov (United States)

We are searching for the permanent electric dipole moment (EDM) of the Radium-225 nucleus. A nonzero nuclear EDM is a signature of CP- and T-violating interactions within nuclei. Currently, the best experimental limits on these interactions are derived from EDM measurements of Mercury-199. The Ra-225 radioisotope (half-life of 15 days) is an attractive alternative because, due to its peculiar shape (nuclear octupole deformation), it is predicted to be a few hundred to a few thousand times more sensitive to these types of interactions than Hg-199. In our measurement scheme, Ra atoms are first laser cooled and trapped in a magneto-optical trap and then transferred to an optical dipole trap (ODT), both of which have already been demonstrated. The ODT is moved to a magnetically-shielded science chamber, and then the atoms are transferred to a perpendicular ODT in which the EDM will be measured. Transfer efficiencies between the two ODT's as high as 60% have been demonstrated. We will report on progress towards measurements of atomic properties necessary for the EDM search and the EDM search itself. Research supported by DOE, Office of Nuclear Physics, contract No. DE-AC02-06CH11357.

Parker, Richard; Bailey, Kevin; Dietrich, Matthew; Greene, John; Holt, Roy; Kalita, Mukut; Korsch, Wolfgang; Lu, Zheng-Tian; Mueller, Peter; O'Conner, Tom; Singh, Jaideep

2012-03-01

34

Wire EDM for Refractory Materials  

Science.gov (United States)

In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

1982-01-01

35

EMERSE: The Electronic Medical Record Search Engine  

Digital Repository Infrastructure Vision for European Research (DRIVER)

EMERSE (The Electronic Medical Record Search Engine) is an intuitive, powerful search engine for free-text documents in the electronic medical record. It offers multiple options for creating complex search queries yet has an interface that is easy enough to be used by those with minimal computer experience. EMERSE is ideal for retrospective chart reviews and data abstraction and may have potential for clinical care as well.

Hanauer, David A.

2006-01-01

36

EDMS - Reaching the Million Mark  

CERN Multimedia

When Christophe Seith from the company Cegelec sat down to work on 14 May 2009 at 10:09 a.m. to create the EDMS document entitled "Rapport tournée PH semaine 20", little did he know that he would be the proud creator of the millionth EDMS document and the happy prize winner of a celebratory bottle of champagne to mark the occasion. In the run up to the creation of the millionth EDMS document the EDMS team had been closely monitoring the steady rise in the EDMS number generator, so as to ensure the switch from the six figured i.d. to seven figures would run smoothly and of course, to be able to congratulate the creator of the millionth EDMS document. From left to right: Stephan Petit (GS-ASE- EDS Section Leader), Christophe Delamare (GS- ASE Group Leader), Christophe Seith, creator of the millionth EDMS document, David Widegren, (GS-ASE- EPS Section Leader). The millionth EDMS document. For t...

2009-01-01

37

Progress towards a nuclear EDM measurement of Ra-225  

Science.gov (United States)

We are developing a long term program to search for the permanent electric dipole moment (EDM) of the Radium-225 nucleus. A nonzero nuclear EDM is a signature of of CP- and T-violating interactions within nuclei. Currently, the best experimental limits on these interactions are derived from EDM measurements of Mercury-199. The Ra-225 radioisotope (half-life of 15 days) is an attractive alternative because, due to its peculiar shape (octupole deformation), it is predicted to be 10^2-10^3 times more sensitive to these types of interactions than Hg-199. In our measurement scheme, Ra atoms are first laser cooled & trapped in a magneto-optical trap (MOT) and then transferred to an optical dipole trap (ODT), both of which have already been demonstrated. Currently being studied is the motion of this ODT into the science chamber and the transfer of atoms into a second ODT. We will report on progress towards measurements of atomic properties necessary for the EDM search and the EDM search itself.

Singh, Jaideep; Dietrich, M. R.; Kalita, M.; Parker, R. H.; Sulai, I. A.; Bailey, K.; Greene, J. P.; Mueller, P.; O'Connor, T. P.; Holt, R. J.; Lu, Z.-T.

2011-06-01

38

CKM benchmarks for electron electric dipole moment experiments  

Science.gov (United States)

All current experiments searching for an electron electric dipole moment (EDM) de are performed with atoms and diatomic molecules. Motivated by significant recent progress in searches for an EDM-type signal in diatomic molecules with an uncompensated electron spin, we provide an estimate for the expected signal in the Standard Model due to the Cabibbo-Kobayashi-Maskawa (CKM) phase. We find that the main contribution originates from the effective electron-nucleon operator e¯i?5eN¯N, induced by a combination of weak and electromagnetic interactions at O(GF2?2), and not by the CKM-induced electron EDM itself. When the resulting atomic P ,T-odd mixing is interpreted as an equivalent electron EDM, this estimate leads to the benchmark deequiv(CKM)˜10-38 ecm.

Pospelov, Maxim; Ritz, Adam

2014-03-01

39

Multiconfiguration Dirac-Hartree-Fock calculations of EDM for Ra, Hg, Yb  

Science.gov (United States)

Using multiconfiguration Dirac-Hartree-Fock (MCDHF) method, we calculated the atomic electric dipole moment (EDM) for Ra, Hg, Yb, arising from nuclear Schiff moment, (P,T)-odd electron-nucleon interactions, and interaction of electron EDM with nuclear electromagnetic field.

Gaigalas, Gediminas; Biero?, Jacek; Radži?t?, Laima

2014-04-01

40

Towards a new measurement of the neutron EDM - The nEDM experiment at PSI/TUM  

International Nuclear Information System (INIS)

Since the 1950's people search for electric dipole moments (EDM) of fundamental systems, an unambiguous manifestation of parity (P) and time reversal symmetry (T) - and therefore CP-violation. Whereas EDMs predicted by the Standard Model (SM) of particle physics are very small, most SM extensions (e.g. Supersymmetry) require large EDMs. These models are already strongly limited by experiments, and a further improvement of the sensitivity of these measurements can provide a unique opportunity to search for new physics. Speaking for the n-EDM collaboration based at PSI and TUM, I present an approach to measure the EDM of the neutron with an accuracy of 5.1028 e.cm or better, corresponding to an increase in sensitivity of nearly two orders of magnitude over the current limits. To achieve this goal, (i) new strong sources of ultra-cold neutrons are being built, as well as (ii) improved control of magnetic fields and (iii) means to control systematic effects is investigated. The final sensitivity goal will be reached in phases, (i) optimizing the existing room temperature apparatus of the former RAL/Sussex/ILL collaboration and gradually implementing new components (2008), (ii) improving the current limits by a factor of 4 by operating the improved apparatus at the strong UCN source at PSI (2009-2010) and (iii) operating a large scale spectrometer to reach the sensitivity goal (2011+)

2009-03-09

 
 
 
 
41

EDMS 6: modern and intuitive  

CERN Multimedia

As announced in Bulletin No. 14-15/2014 (see here), a new version of the system used to manage technical data and data concerning CERN equipment (EDMS, Engineering and Equipment Data Management Service) is now available.   A unique interface for all data linked to CERN’s engineering work, EDMS currently stores more than 1.2 million documents containing almost 2 million files, guaranteeing the transfer of protected information and knowledge to future generations of engineers and scientists at CERN, be it the design data and documentation for a specific object (technical specifications, test procedures, non-conformities, drawings, etc.) or technical information about the Laboratory’s infrastructure and scientific equipment. In a few months, the new EDMS 6 system will replace the current system definitively, offering its 13,000 users a more modern and intuitive interface that meets their expectations. “We've been working in close collaboration with some of ...

Anaïs Schaeffer

2014-01-01

42

Development of Thermal Ionizer for the Search of the Electron Electric Dipole Moment  

Science.gov (United States)

A non-zero Electric Dipole Moment (EDM) of an elementary particle means the violation of the time-reversal symmetry and the CP violation assuming the CPT invariance. The super symmetry model (SUSY) predicts the EDM large enough to be observed with the modern experimental technique. In alkali atoms, an electron EDM results in an atomic EDM enhanced by the factor ˜Z^3?^2, especially francium (Fr) has the largest enhancement factor ˜ 1150. However Fr is a radioactive atom with a finite life time, we need to establish the technique to produce over 10^7 atoms/sec, cool and collect them quickly into laser trap apparatus as a cold dense cloud of neutral atoms to measure the EDM accurately. Thermal Ionizer produce the high intensity Fr ion using a fusion reaction of ^18O+^197Au->^210Fr+5n with a primary beam energy E^18O ˜100 MeV. This ionizer consists of the Au target surrounded by the high temperature oven to stop the ion spreading out. Thanks to the small extraction electrode hole, we can realize the small emittance Fr beam, and the high transmission efficiency. We have achieved to produce over ˜10^4 atom/sec, and transport them along 3 meter without losing the Fr ions.

Hayamizu, Tomohiro; Oikawa, Akihito; Takahashi, Toshiya; Yoshida, Hidetomo; Itoh, Masatoshi; Sakemi, Yasuhiro

2009-10-01

43

Edme Mariotte and Newton's Cradle  

Science.gov (United States)

The first recorded experiments describing the phenomena made popular by Newton's cradle appear to be those conducted by Edme Mariotte around 1670. He was quoted in Newton's "Principia," along with Wren, Wallis, and Huygens, as having conducted pioneering experiments on the collisions of pendulum balls. Each of these authors concluded that momentum…

Cross, Rod

2012-01-01

44

Optimizing the Machining Parameters of Micro-EDM for Inconel 718  

Directory of Open Access Journals (Sweden)

Full Text Available This paper aims to study on the feasibility of micron size hole manufacturing using micro Electric Discharge Machining (Micro-EDM. Main and auxiliary unit of the micro-EDM machine tool and their functions are described in some detail. The technological and electrical parameters that are effective in Micro-EDM are stated explicitly. Geometry of the machined micro-holes and resolidified material around the hole entrance are observed. Several descriptive pictures, obtained by Scanning Electron Microscope (SEM are included to understand the phenomena. EDM is an important process in the field of micro machining. However, a number of issues remain to be solved in order to successfully implement it an industrial environment. This study investigates the optimization of machining parameters for machining in micro EDM. Here, the overcut and the Metal Removal Rate (MRR and Tool wear ratio are targeted. The study focuses on a specific combination of electrode and work piece material and proposes a typical method for micro EDM process optimization. The cutting of the Inconel 718 using Micro EDM with a brass electrode by using Taguchi methodology has been reported. The Taguchi method is used to formulate the experiment layout, to analyze the effect of each parameter on the machining characteristics and to predict the optimal choice for each EDM parameters like Discharge current, Pulse on time, Pulse off time. It found that these parameters have a significant influence on the machining characteristics such as Metal Removal Rate (MRR, Overcut and Tool wear ratio.

R. Venkatesan

2012-01-01

45

Snapshot of Micro EDM technology for industry  

DEFF Research Database (Denmark)

In this paper, the performances and requirements of conventional Electrical Discharge Machining (EDM) and micro EDM technologies are described in order to explore obstacles to the introduction of micro EDM technologies into industrial environment. Special attention is given to machine tool accuracy, machining accuracy, electric pulses, pulse generators and environmental requirements. EDM has been widely used in toolmaking industry to produce dies, moulds and other tools for mass production. It was also found suitable for machining meso and micro structures, since its removal mechanism induces very low machining forces. In particular, a new technology called micro EDM milling, employing milling like strategies, was developed to enable the machining of 3D micro features. Keyword: Micro EDM milling,Microtechnologies,Pulse generator,Accuracy,Die-sinking EDM

Valentinčič, J.; Bissacco, Giuliano

2009-01-01

46

End-User Attitudes Towards EDM Use in Construction Project Work: Case Study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This article reports on a cross-sectional case study of a large construction project in which Electronic document management (EDM) was used. Attitudes towards EDM from the perspective of individual end users were investigated. Responses from a survey were combined with data from system usage log files to obtain an overview of attitudes prevalent in different user segments of the total population of 334 users. The survey was followed by semi-structured interviews with representative users. A s...

2007-01-01

47

The new neutron EDM experiment at the FRM-II  

International Nuclear Information System (INIS)

Since the 1950's people have been searching for electric dipole moments (EDMs) of fundamental particles. This is a very promising approach to find yet unknown manifestations of broken underlying symmetries in the early Universe. Although these experiments are among the most precise in physics, no EDM has been observed so far. In this talk a next generation approach with a sensitivity of -28 ecm (3?) for the neutron EDM based at the FRM-II neutron source is presented. Ramsey's method of separated oscillatory fields is applied to trapped ultra-cold neutrons (UCNs) in vacuum. For the investigation of systematic effects a sophisticated strategy of various means to control ambient parameters on an unprecedented level of accuracy is currently being set up. The construction is planned to be finished by end of 2013, followed by the first measurements with UCNs in 2014. An overview of the overall strategy, main systems for magnetic field control and magnetometry, as well as the current status of the ongoing implementation on site is shown.

2012-03-19

48

Search Hanford accessible reports electronically system configuration management plan  

Energy Technology Data Exchange (ETDEWEB)

This Software Configuration Management Plan (SCMP) provides the requirements for control of the Search Hanford Accessible Reports Electronically (SHARE) software and documentation. The SHARE system consists of the TOPIC Text Search and Retrieval software and the programs necessary to extract information from other sources to be placed in SHARE.

White, E.L.

1995-01-01

49

Double core polarization contribution to atomic PNC and EDM calculations  

CERN Document Server

We present a detailed study of the effect of the double core polarization (the polarization of the core electrons due to the simultaneous action of the electric dipole and parity-violating weak fields) for amplitudes of the $ss$ and $sd$ parity non-conserving transitions in Rb, Cs, Ba +, La 2+, Tl, Fr, Ra +, Ac 2+ and Th 3+ as well as electron EDM enhancement factors for the ground states of the above neutral atoms and Au. This effect is quite large and has the potential to resolve some disagreement between calculations in the literature. It also has significant consequences for the use of experimental data in the accuracy analysis.

Roberts, B M; Flambaum, V V

2013-01-01

50

Configuration interaction calculation of hyperfine and P,T-odd constants on ^{207}PbO excited states for the electron EDM experiments  

CERN Document Server

We report first configuration interaction calculations of hyperfine constants A_\\parallel and the effective electric field W_d acting on the electric dipole moment of the electron, in two excited electronic states of ^{207}PbO. The obtained hyperfine constants, A_\\parallel = -3826 MHz for the a(1) state and A_\\parallel = 4887 MHz for the B(1) state, are in very good agreement with the experimental data, -4113 MHz and 5000 \\pm 200 MHz, respectively. We find W_d = -(6.1 ^{+1.8}_{-0.6}) 10^{24} Hz/(e cm) for a(1), and W_d = (8.0 \\pm 1.6) 10^{24} Hz/(e cm) for B(1). The obtained values are analyzed and compared to recent relativistic coupled cluster results and a semiempirical estimate of W_d for the a(1) state.

Petrov, A N; Isaev, T A; Mosyagin, N S; De Mille, D P

2004-01-01

51

Search for scalar electrons at PEP  

International Nuclear Information System (INIS)

Experimental results from e+e- reactions at the Positron Electron Project (PEP) using the High Resolution Spectrometer (HRS) are presented. Events with two electrons, and no other charged particles, in the final state are studied. Limits are given for the production of scalar-electrons predicted by models based on supersymmetry. In particular the pair production of such particles through s-channel single photon annihilation and t-channel inelastic scattering is considered. The data are well described by quantum electrodynamics (QED) but we observe one event which is also consistent with a supersymmetric model. Using this single event we find that the mass, M/sub se/, of these scalar-electrons es excluded, to 95% CL, in the range 1.8 less than or equal to M/sub se/ less than or equal to 14.2 GeV/c2. A description of the HRS detector is given with particular emphasis on the electronic trigger system

1983-01-01

52

Search for excited electrons using the ZEUS detector  

International Nuclear Information System (INIS)

This paper reports a search for excited electrons at the HERA electron-proton collider. In a sample corresponding to an integrated luminosity of 26 nb-1, no evidence was found for any resonant state decaying into e-?, ?W- or e-Z0. Limits on the coupling strength of an excited electron have been determined for masses between 45 and 225 GeV. This study also reports the observation of the wide-angle e? Compton scattering process. (orig.)

1993-01-01

53

Micro-EDM for silicon microstructure fabrication  

Science.gov (United States)

Currently, most silicon microstructures used in microstructures are produced by photolithographic methods. The reason for this is the well-developed etching technology, used in microelectronics, that has been transferred to the microsystem domain. But since the making of an arbitrary shape or angle on silicon mainly depends on the crystal orientation, some severe limits exist in the production of 3D structures. Electro-discharge machining (EDM) is basically a thermal process. During the EDM process material is removed by electric sparking. It is therefore completely different from etching. In this work, micro-EDM is introduce as a potential approach for solving the above mentioned drawbacks. First, this work presents several testing experiments with different process parameters to investigate the influence of the micro-EDM process on the silicon structure. Main emphasis is put on the surface roughness and on avoiding microcracks generated by the sparking process. It is found that microstructures with a sufficiently low surface roughness and with small microcracks can be produced. The remainder of the work concentrates on making small beam structures, which is a common structure in many microsensor designs. It is found that for a wafer thickness of 650 micrometers , the thinnest beam that can be produced is about 30 micrometers wide. This means that micro-EDM can offer an aspect ratio of 20 in combination with a god dimensional control.

Song, Xiaozhong; Reynaerts, Dominiek; Meeusen, Wim; Van Brussel, Hendrik

1999-03-01

54

Can electronic search engines optimize screening of search results in systematic reviews: an empirical study  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Most electronic search efforts directed at identifying primary studies for inclusion in systematic reviews rely on the optimal Boolean search features of search interfaces such as DIALOG® and Ovid™. Our objective is to test the ability of an Ultraseek® search engine to rank MEDLINE® records of the included studies of Cochrane reviews within the top half of all the records retrieved by the Boolean MEDLINE search used by the reviewers. Methods Collections were created using the MEDLINE bibliographic records of included and excluded studies listed in the review and all records retrieved by the MEDLINE search. Records were converted to individual HTML files. Collections of records were indexed and searched through a statistical search engine, Ultraseek, using review-specific search terms. Our data sources, systematic reviews published in the Cochrane library, were included if they reported using at least one phase of the Cochrane Highly Sensitive Search Strategy (HSSS, provided citations for both included and excluded studies and conducted a meta-analysis using a binary outcome measure. Reviews were selected if they yielded between 1000–6000 records when the MEDLINE search strategy was replicated. Results Nine Cochrane reviews were included. Included studies within the Cochrane reviews were found within the first 500 retrieved studies more often than would be expected by chance. Across all reviews, recall of included studies into the top 500 was 0.70. There was no statistically significant difference in ranking when comparing included studies with just the subset of excluded studies listed as excluded in the published review. Conclusion The relevance ranking provided by the search engine was better than expected by chance and shows promise for the preliminary evaluation of large results from Boolean searches. A statistical search engine does not appear to be able to make fine discriminations concerning the relevance of bibliographic records that have been pre-screened by systematic reviewers.

Clifford Tammy J

2006-02-01

55

The neutron EDM experiment at the SNS  

Science.gov (United States)

A non-zero neutron electric dipole moment (EDM) would violate both parity and time reversal symmetry and measurement of this quantity will help to understand the source of baryon asymmetry in the universe. An effort is underway at the Spallation Neutron Source at Oak Ridge National Laboratory to measure the neutron EDM by detecting a modulation in the neutron spin precession frequency correlated with reversal of a strong electric field. In this experiment, ultra-cold neutrons are produced in liquid helium where the EDM is measured in situ. A trace amount of ^3He is used as a co-magnetometer and as a detector of the neutron spin precession. Experimental details and projected results will be presented.

Crawford, Christopher

2010-10-01

56

Search for excited electrons in ep collisions at HERA  

International Nuclear Information System (INIS)

A search for excited electrons is performed using the full e±p data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb-1. The electroweak decays of excited electrons e* ?e?, e* ?eZ and e* ??W with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for excited electron production is found. Mass dependent exclusion limits on e* production cross sections and on the ratio f/? of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited electron searches. The e* production via contact interactions is also addressed for the first time in ep collisions. (orig.)

2008-05-29

57

Search for excited electrons in ep collisions at HERA  

International Nuclear Information System (INIS)

A search for excited electrons is performed using the full e±p data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb-1. The electroweak decays of excited electrons e*?e?, e*?eZ and e*??W with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for excited electron production is found. Mass dependent exclusion limits on e* production cross sections and on the ratio f/? of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited electron searches. The e* production via contact interactions is also addressed for the first time in ep collisions

2008-08-14

58

Search for excited electrons in ep collisions at HERA  

Energy Technology Data Exchange (ETDEWEB)

A search for excited electrons is performed using the full e{sup {+-}}p data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb{sup -1}. The electroweak decays of excited electrons e*{yields}e{gamma}, e*{yields}eZ and e*{yields}{nu}W with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for excited electron production is found. Mass dependent exclusion limits on e* production cross sections and on the ratio f/{lambda} of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited electron searches. The e* production via contact interactions is also addressed for the first time in ep collisions.

Aaron, F.D.; Alexa, C. [National Institute for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Andreev, V. [Lebedev Physical Institute, Moscow (Russian Federation); Antunovic, B.; Aplin, S. [DESY, Hamburg (Germany); Asmone, A. [Dipartimento di Fisica, Universita di Roma Tre and INFN Roma 3, Roma (Italy); Astvatsatourov, A. [Inter-University Institute for High Energies ULB-VUB, Universiteit Antwerpen, Antwerpen (Belgium); Bacchetta, A. [DESY, Hamburg (Germany); Backovic, S. [Faculty of Science, University of Montenegro, Podgorica (Montenegro); Baghdasaryan, A. [Yerevan Physics Institute, Yerevan (Armenia); Baranov, P. [Lebedev Physical Institute, Moscow (Russian Federation); Barrelet, E. [LPNHE, Universites Paris VI and VII, IN2P3-CNRS, Paris (France); Bartel, W.; Beckingham, M. [DESY, Hamburg (Germany); Begzsuren, K. [Institute of Physics and Technology of the Mongolian Academy of Sciences, Ulaanbaatar (Mongolia); Behnke, O. [Physikalisches Institut, Universitaet Heidelberg, Heidelberg (Germany); Belousov, A. [Lebedev Physical Institute, Moscow (Russian Federation); Berger, N. [Institut fuer Teilchenphysik, ETH, Zuerich (Switzerland); Bizot, J.C. [LAL, Universite Paris-Sud, CNRS/IN2P3, Orsay (France); Boenig, M.-O. [Institut fuer Physik, TU Dortmund, Dortmund (Germany)] (and others)

2008-08-14

59

Study of the Diffusion of Carbon, Its Sources, and Effect on Finishing Micro-EDM Performance of Cemented Carbide  

Science.gov (United States)

Apart from the necessity of surface modification based on different applications, in most of the cases, diffusion of carbon or foreign particles on the workpiece surface during micro-electrodischarge machining (micro-EDM) is avoidable, especially in finishing micro-EDM. This study aims to investigate different sources of materials that migrate to the machined surface during fine-finishing of micro-EDM of cemented tungsten carbide (WC-Co). The machined surfaces have been examined under scanning electron microscope and energy dispersive x-ray to investigate the changes in chemical composition. It has been observed that during finishing of micro-EDM, the major source of materials' transfer to both the workpiece and electrode is the diffusion of carbon that comes from the decomposition of the hydrocarbon dielectric. In addition, materials from both workpiece and electrode transfer to each other based on machining conditions and discharge energy. The migration occurs more frequently at lower gap voltages during die-sinking with micro-EDM because of low spark gap and stationary tool electrode. Milling micro-EDM results in lower amount of carbon migration and fewer surface defects that improve the overall surface finish significantly.

Jahan, M. P.; Rahman, M.; Wong, Y. S.

2012-08-01

60

Search for oscillations of muon neutrinos to electron neutrinos  

International Nuclear Information System (INIS)

The author has searched in the heavy liquid bubble chamber BEBC for electron neutrino charge current events which could arise from oscillation of the muon neutrinos (average energy ?1.5 GeV) obtained with a low energy proton beam at the CERN PS targeted 825 m upstream from BEBC. The appearance of electron neutrino CC interactions provides a sensitive indication of nu/sub ?/ ? nu/sub e/ oscillation. The author observed 460 muon neutrino CC events and 4 electron neutrino CC events with an estimated background of 3.5 electron neutrino CC events. Using the likelihood ratio method to test the oscillation hypothesis, the author finds no evidence for nu/sub ?/ ? nu/sub e/ oscillation and set the limits ?m"2 ? 0.13 eV"2 (maximal mixing) and sin"22theta ? 0.018 for ?m2 = 3 eV"2 at 90% confidence level

1986-01-01

 
 
 
 
61

Searching of Double Electron Capture in the TGV Experiment  

CERN Multimedia

The first investigations of the rare nuclear process - double electron capture of $^{106}$Cd have been performed using the low-background multi-detector spectrometer TGV-2 (Telescope Germanium Vertical). The preliminary results of calculations of experimental data obtained using 11.3 and 10 g of enriched $^{106}$Cd, and 14.5 g of natural Cd were presented. The sensitivity of T$_{1/2}^{EC/EC}>2.6\\cdot10^{19}$y (90\\% CL) was obtained for the searching of double electron capture of $^{106}$Cd ($0^{+} - 0^{+}$) in the investigation of natural Cd.

Brudanin, V B; Briançon, C; Benes, P; Vylov, T D; Gusev, K N; Egorov, V G; Klimenko, A A; Kovalenko, V E; Korolev, N A; Salamatin, A V; Timkov, V V; Cermák, P; Shirchenko, M V; Shitov, Yu A; Stekl, I

2004-01-01

62

Query Log Analysis of an Electronic Health Record Search Engine  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We analyzed a longitudinal collection of query logs of a full-text search engine designed to facilitate information retrieval in electronic health records (EHR). The collection, 202,905 queries and 35,928 user sessions recorded over a course of 4 years, represents the information-seeking behavior of 533 medical professionals, including frontline practitioners, coding personnel, patient safety officers, and biomedical researchers for patient data stored in EHR systems. In this paper, we presen...

Yang, Lei; Mei, Qiaozhu; Zheng, Kai; Hanauer, David A.

2011-01-01

63

Search techniques in electronic dictionaries: a classification for translators  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Translators, and language professionals in general, have long claimed that dictionaries are deficient, especially regarding access and updating of content. Some authors have also noted that these deficiencies are compounded by the fact that language professionals do not receive (proper) training in dictionary use, and therefore do not fully benefit from them. Electronic dictionaries include new search capabilities, not found in traditional dictionaries, that could meet users’ needs. However...

Pastor, Vero?nica; Alcina Caudet, Amparo

2010-01-01

64

Broadband velocity modulation spectroscopy of HfF^+: towards a measurement of the electron electric dipole moment  

CERN Document Server

Precision spectroscopy of trapped HfF^+ will be used in a search for the permanent electric dipole moment of the electron (eEDM). While this dipole moment has yet to be observed, various extensions to the standard model of particle physics (such as supersymmetry) predict values that are close to the current limit. We present extensive survey spectroscopy of 19 bands covering nearly 5000 cm^(-1) using both frequency-comb and single-frequency laser velocity-modulation spectroscopy. We obtain high-precision rovibrational constants for eight electronic states including those that will be necessary for state preparation and readout in an actual eEDM experiment.

Cossel, Kevin C; Sinclair, Laura C; Coffey, Tyler; Skripnikov, Leonid V; Petrov, Alexander N; Mosyagin, Nikolai S; Titov, Anatoly V; Field, Robert W; Meyer, Edmund R; Cornell, Eric A; Ye, Jun

2012-01-01

65

Development of the Measurement System for the Search of an Electric Dipole Moment of the Electron with Laser-Cooled Francium Atoms  

Directory of Open Access Journals (Sweden)

Full Text Available We plan to measure the permanent electric dipole moment (EDM of the electron, which has the sensitivity to the CP violation in theories beyond the standard model by using the laser-cooled francium (Fr atom. This paper reports the present status of the EDM measurement system. A high voltage application system was constructed in order to produce the strong electric field (100 kV/cm needed for the experiment. After conditioning, the leakage current was 10 pA when a high voltage of 43 kV was applied. Also, a drift of an environmental field was measured at the planned location of the Fr-EDM experiment. The drift is suppressed at present down to the level of 10 pT by installing a 4-layermagnetic shield. Improvements are still needed to reach the required field stability of 1 fT.

Inoue T.

2014-03-01

66

Empirical Modeling of EDM Parameters Using Grey Relational Analysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Optimization of multi criteria problems is a great need of producers to product precision parts with low costs. Many methods such as Taguchi and Response Surface Methodology have been employed for optimization of EDM process. However there are few researches involve the optimization of multi-response problem in EDM process. The attempt of this paper is to optimize multiple performance characteristics of EDM process using Grey relational analysis based on Taguchi orthogonal array. The r...

2008-01-01

67

CryoEDM: A cryogenic experiment to measure the neutron electric dipole moment  

International Nuclear Information System (INIS)

CryoEDM is an experiment that aims to measure the electric dipole moment (EDM) of the neutron to a precision of 10-28 e cm. A description of CryoEDM, the apparatus, technologies and commissioning is presented.

2009-12-01

68

SEARCH FOR A NEUTRON ELECTRIC DIPOLE MOMENT  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To search for evidence of a breakdown of symmetry under the time reversal transformation, a magnetic resonance measurement is made to detect an electric dipole moment (EDM) of ultracold neutrons stored for periods ?60s in the presence of a strong electric field. The measured neutron EDM is (0.3 ± 4.8) x 10-25 ecm.

Morse, J.

1984-01-01

69

EDM Machine Modified For Micro Drilling In DAC Experiments  

Science.gov (United States)

A JOEMARS Electric discharge machine (EDM) has been modified for micro drilling of gasket holes for high pressure experiments using a diamond anvil cell. We were able to use normal tungsten carbide drill bits that are used for drilling micro holes manually with the EDM. The drilled holes were free of burr formation and had a nice surface finish.

Lonappan, Dayana; Shekar, N. V. Chandra; Sundaram, L. M.; Edwin, T.; Sahu, P. Ch.

2011-07-01

70

Adoption processes for EDM, EDI and BIM technologies in the construction industry  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Three strategically important uses of IT in the construction industry are the storage and management of project documents on webservers (EDM), the electronic handling of orders and invoices between companies (EDI) and the use of 3-D models including non-geometrical attributes for integrated design and construction (BIM). In a broad longitudinal survey study of IT use in the Swedish Construction Industry the extent of use of these techniques was measured in 1998, 2000 and 2007. The results sho...

2011-01-01

71

Library Instruction and College Student Self-Efficacy in Electronic Information Searching.  

Science.gov (United States)

Explores whether library instruction can enhance college students' self-efficacy in electronic information searching. Assesses self-efficacy before and after library instruction; examines how self-esteem is related to students' attitudes toward acquiring electronic search skills, their emotions, and search performance; and discusses implications…

Ren, Wen-Hua

2000-01-01

72

LIPSS Free-Electron Laser Searches for Dark Matter  

Energy Technology Data Exchange (ETDEWEB)

A variety of Dark Matter particle candidates have been hypothesized by physics Beyond the Standard Model (BSM) in the very light (10{sup -6} - 10{sup -3} eV) range. In the past decade several international groups have conducted laboratory experiments designed to either produce such particles or extend the boundaries in parameter space. The LIght Pseudo-scalar and Scalar Search (LIPSS) Collaboration, using the 'Light Shining through a Wall' (LSW) technique, passes the high average power photon beam from Jefferson Lab's Free-Electron Laser through a magnetic field upstream from a mirror and optical beam dump. Light Neutral Bosons (LNBs), generated by coupling of photons with the magnetic field, pass through the mirror ('the Wall') into an identical magnetic field where they revert to detectable photons by the same coupling process. While no evidence of LNBs was evident, new scalar coupling boundaries were established. New constraints were also determined for hypothetical para-photons and for millicharged fermions. We will describe our experimental setup and results for LNBs, para-photons, and milli-charged fermions. Plans for chameleon particle searches are underway.

Afanaciev, Andrei; Beard, Kevin; Biallas, George; Boyce, James R; Minarni, M; Ramdon, R; Robinson, Taylor; Shinn, Michelle D

2011-09-01

73

Development of a cryogenic detector using superheated superconducting tin granules in EDM measurement and life measurement of neutrons  

International Nuclear Information System (INIS)

EDM measurement and life measurement of neutrons is carried out by using the ultra cold neutrons produced originally in liquid helium through the superthermal method. The detection of UCNs and electrons in the low-temperature environment improves the efficiency highly. We reports our current experiments on the detection of neutrons using superheated superconducting granules (SSG) and the future planning. (author)

2001-12-01

74

Electric Dipole Moments of Neutron and Electron in Supersymmetric Model  

CERN Document Server

The electric dipole moments (EDMs) of the neutron and the electron are reviewed within the framework of the supersymmetric standard model (SSM) based on grand unified theories coupled to N=1 supergravity. Taking into account one-loop and two-loop contributions to the EDMs, we explore SSM parameter space consistent with experiments and discuss predicted values for the EDMs. Implications of baryon asymmetry of our universe for the EDMs are also discussed.

Aoki, M; Sugamoto, A; Oshimo, N; Aoki, Mayumi; Kadoyoshi, Tomoko; Sugamoto, Akio; Oshimo, Noriyuki

1997-01-01

75

The neutron EDM in the SM: a review  

International Nuclear Information System (INIS)

We review the status of the electric dipole moment (EDM) of neutron in the Standard Model (SM). The contributions of the strong and electroweak interactions are discussed separately. In each case the structure of Lagrangian and the sources of CP violation are specified, and subsequently calculational details are given. These two contributions to the neutron EDM exist in any extension of the SM including supersymmetry, two-doublet models as well as models with more than three generations of fermions. We briefly discuss the status of the neutron EDM in such extensions and give the relevant literature. (author)

2000-01-01

76

Construction Of An Apparatus And Preliminary Measurements For A Search For The Electric Dipole Moment Of The Electron Using Lead Monoxide  

CERN Document Server

We have developed a vapor cell and heater for an experiment to search for an electric dipole moment (EDM) of the electron using the metastable state a(1)[3?+] of lead monoxide. Using our apparatus and the method of quantum beat spectroscopy, we have measured the g-factors of the a(1)(3?+) state. We obtain (g∥)? = 1.8571 ± 0.0041 for the J = 1? component and ( g∥)+ = 1.8584 ± 0.0045 for the J = 1+ component. We also establish a limit on the difference of the g-factors of dgg=2˙ g&dvbm0;- -g&dvbm0;+ g∥- + g∥+ < 2.3 · 10?3 (90% CL). In the course of our measurements, we have demonstrated shot-noise limited sensitivity to the Zeeman quantum beat frequency of 35HzHz . We point out relatively straightforward improvements, which should increase the statistical sensitivity to 100mHzHz in the near future. With this level of sensitivity, it should be possible to measure an...

Bay, F

2003-01-01

77

Search Hanford accessible reports electronically system design description. Revision 1  

Energy Technology Data Exchange (ETDEWEB)

The Search Hanford Accessible Records Electronically (SHARE) system was produced by a combined team of personnel from Westinghouse Hanford Company (WHC) Corrective Action Data Systems (CADS) and Information Resource Management (IRM) Information and Scientific Systems (ISS) organizations. The ESQD Text Evaluation and exchange Tool (ETEXT) prototype was used as a basis for the requirements used to support this design/build effort. TOPIC was used to build the SHARE application. TOPIC is a text search and retrieval software product produced by the Verity Corporation. The TOPIC source code is not provided with the product, and the programs cannot be changed. TOPIC can be customized for special requirements. The software is fully documented. Help messages, menu and screen layouts, command edits and options, and internal system design are all described in the TOPIC documentation. This System Design Description (SDD) will not reiterate the TOPIC documentation and design. Instead, it will focus on the SHARE installation of TOPIC. This SDD is designed to assist the SHARE database/infobase administrator (DBA) in maintaining and supporting the application. It assumes that the assigned DBA is knowledgeable in using the TOPIC product, and is also knowledgeable in using a personal computer (PC), Disk Operating System (DOS) commands, and the document WHC-CM-3-10. SHARE is an Impact Level 4 system, and all activities related to SHARE must conform with the WHC-CM-3-10 procedures for an Impact Level 4 system. The Alternatives Analysis will be treated as a level 3-Q document, to allow for reference by potential future projects.

Gilomen, T.L.

1995-12-31

78

Neutron storage time measurement for the neutron EDM experiment  

Science.gov (United States)

A new experiment to search for the neutron electric dipole moment (nEDM) is under development for installation at the Spallation Neutron Source (SNS) at Oakridge National Laboratory. The experiment will use ultra-cold neutrons (UCN) stored in superfluid helium, along with ^3He atoms acting as a neutron spin analyzer and comagnetometer. One crucial factor affecting the ultimate sensitivity of the experiment is the neutron storage time that can be obtained in the acrylic measurement cell. The acrylic cell walls will be coated with deuterated polystyrene (dPS), which is expected to give a wall loss factor of ˜< 10-5 per bounce when cooled below the point where upscattering by hydrogen impurities contribute to UCN losses. We are currently preparing a measurement at Los Alamos to verify that a 10-5 wall loss factor can be achieved in a dPS coated acrylic test cell. The planned measurement will investigate the temperature dependence of the UCN storage time in the dPS coated test cell between room temperature and below 20 K.

Griffith, W. Clark; Ito, Takeyasu; Ramsey, John; Makela, Mark; Clayton, Steven; Hennings-Yeomans, Raul; Saidur Rahaman, M.; Currie, Scott; Womack, Todd; Sondheim, Walter; Cooper, Martin

2010-11-01

79

Metallurgical Effects from Conventional, EDM, and Electrochemical Drilling.  

Science.gov (United States)

Poor surface integrity of a small deep hole can serve as an initiation point for failure. The drilling methods evaluated in this study were peck drilling, shaped tube electrolytic machining (STEM drilling) and electric discharge (EDM) drilling. All three ...

J. E. Fuller

1980-01-01

80

Foldy-Wouthuysen transformed EDM operator in atomic system  

CERN Document Server

We present a generalized Schiff transformation on electric dipole moments (EDM) in quantum field theory. By the unitary transformation, the time and parity violating interaction $ ig \\bar \\psi \\sigma_{\\mu \

Asaga, T; Hiramoto, M; Asaga, Tomoko; Fujita, Takehisa; Hiramoto, Makoto

2000-01-01

 
 
 
 
81

Vertical EDM (Electric Discharge Machining) Using Modular Programming.  

Science.gov (United States)

The usual function of computer numerically controlled (CNC) machining programs is to specify a sequence of machining operations. When CNC is applied to electric discharge machining (EDM), the possibilities and needs are much greater. This paper describes ...

J. E. Fuller

1989-01-01

82

A search for electron cyclotron maser emission from compact binaries  

CERN Document Server

Unipolar induction (UI) is a fundamental physical process, which occurs when a conducting body transverses a magnetic field. It has been suggested that UI is operating in RX J0806+15 and RX J1914+24, which are believed to be ultra-compact binaries with orbital periods of 5.4 min and 9.6 min respectively. The UI model predicts that those two sources may be electron cyclotron maser sources at radio wavelengths. Other systems in which UI has been predicted to occur are short period extra-solar terrestrial planets with conducting cores. If UI is present, circularly polarised radio emission is predicted to be emitted. We have searched for this predicted radio emission from short period binaries using the VLA and ATCA. In one epoch we find evidence for a radio source, coincident in position with the optical position of RX J0806+15. Although we cannot completely exclude that this is a chance alignment between the position of RX J0806+15 and an artifact in the data reduction process, the fact that it was detected at ...

Ramsay, Gavin; Wu, Kinwah; Slee, Bruce; Saxton, Curtis

2007-01-01

83

Micro-Hole Multi-Point Punching System Using Punch and Die Made by EDM  

Science.gov (United States)

In this research a multi-point micro punch and die system was developed. The process of electric discharge machining (EDM) was used to produce both the punch and die. The punches were machined from a 5 mm diameter tungsten and a 10 mm diameter tool steel round rods by wire electric discharge machining (WEDM), using a 200 µm diameter wire electrode. The die holes were made using the punch as the electrode. The EDM process of the holes was carried out on a newly developed desktop EDM machine. The punch and die placed on a micro-die set and then on a micro press were used to produce micro-holes using an automatic control system developed for this process. Experiments to produce 50 µm to 67 µm square micro-holes on 50 µm thick aluminum, 30 µm thick copper and 20 µm thick stainless steel foils were conducted. The capabilities of multi-point punching using the tungsten punch and a tool steel punch were examined and tungsten was chosen as the material of choice for making the punch tool. A scanning electron microscope confirmed that the holes produced are clean, and the sheared surfaces smooth. The punch tool showed no signs of deformation or cracks even after repeated punching.

Broomfield, Mark; Mori, Toshihiko; Mikuriya, Teruaki; Tachibana, Kazushi

84

Machining of Cemented Tungsten Carbide using EDM  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, we investigate the possibility of machining cemented tungsten carbide WC+6% Co by using copper. Tungsten carbide is hard and brittle with low thermal conductivity and low thermal expansion. The high resistant to abrasive wear and high melting point are the main reason for the selection of these materials for large number of applications such as machining tool and die material. The hardness of WC+Co primarily depends on the average grain size and cobalt content. The difficulty when machining cemented tungsten carbide comes from the thermal stress. The micro cracks enlarge, which leads to macro crack and fragmentation. This can be referred to the low thermal expansion, thermal conductivity and brittleness, which create a high thermal stress. Generally, cooling and removal of the cracked particles are difficult. In order to develop the optimal machining process for the desirable machining response, L9 Taguchi Orthogonal Array (OA were used. This orthogonal array is used for optimization of the following variables; Peak-Current (IP, pulse ON-Time (ON, pulse OFF-Time (OFF and Gap-Voltage (GAP. The results show that it’s possible to EDMing WC-Co using copper electrode at very low energy setting but at the expense of material removal rate MRR.

A.M.A. Rani

2011-01-01

85

Using a helical micro-tool in micro-EDM combined with ultrasonic vibration for micro-hole machining  

Science.gov (United States)

This paper presents a novel process using micro-electro-discharge- machining (micro-EDM) combined with ultrasonic vibration by a helical micro-tool electrode to drill and finish micro-holes. During the machining processes, a micro-tool is directly fabricated by wire electro-discharge grinding (WEDG) using micro-EDM combined with various methods for machining the micro-hole and by ultrasonic vibration to finish the hole wall. In this work, circular micro-holes are machined in a high nickel alloy by cylindrical and helical electrodes. Using a helical micro-tool electrode for micro-EDM combined with ultrasonic vibration (HE-MEDM-UV) can substantially reduce the EDM gap, taper and machining time for deep micro-hole drilling. In addition, using a helical micro-tool with micro ultrasonic vibration finishing (HE-MUVF), good surface quality and less taper of the hole wall can be obtained by applying a suitable electrode step variation, rotational speed and ultrasonic amplitude with a machining time of approximately 25 min. According to scanning electron microscopy (SEM) micrographs and atomic force microscopy (AFM) measurement, HE-MUVF can indeed improve the surface roughness from 1.345 µm Rmax before finishing to 0.58 µm Rmax after HE-MUVF. This result demonstrates that using HE-MEDM-UV combined with MUVF can yield micro-holes of precise shape and smooth surface.

Hung, Jung-Chou; Lin, Jui-Kuan; Yan, Biing-Hwa; Liu, Hung-Sung; Ho, Ping-Hsing

2006-12-01

86

A search for single electron production in electron positron annihilation at E = 29 GeV  

International Nuclear Information System (INIS)

This thesis presents experimental results from the ASP detector which took data on e+e- interactions in the PEP storage ring at SLAC. Its design was particularly suitable for searching for production of supersymmetric particles. The motivations for and phenomenology of Supersymmetry are discussed. In particular, the production of a single supersymmetric electron (''selectron'', e) in combination with a supersymmetric photon (''photino'', ?) would result in events in which a single electron and no other particles are observed in the detector at an e+e- collider such as PEP, provided the masses of these particles are not too large. Such events would also result from the production of a single supersymmetric W-boson (''wino'', W) in combination with a supersymmetric neutrino (''sneutrino'', ?). These processes make it possible to search for electrons and winos with masses greater than the beam energy. Observation of these unusual events would distinctly indicate the production of new particles. The ASP detector was designed to be hermetic and to provide efficient event reconstruction for low multiplicity events. The detector is described and its performance is evaluated; it is found to be well-suited to this study. The data sample collected with the detector was thoroughly analyzed for evidence of single-electron events. The various possible background processes are considered and Monte Carlo calculations of the distributions from single selectron and single wino production are presented. Using this information an efficient off-line event selection process was developed, and it is described in detail. 82 refs., 41 figs., 4 tabs

1989-01-01

87

Study of an ultrafine w-EDM technique  

Science.gov (United States)

A precision ultrafine w-EDM (wire electrical discharge machining) technique specifically for machining intricate parts and structures is developed in this paper. A thumb-sized and versatile w-EDM device equipped with a complete control system for wire tension (ultrafine tungsten wire of 13 µm diameter) is designed and employed for the study of ultrafine w-EDM. The tension of the wire electrode is controlled by magnetic repulsive force to steady the wire during machining. Ultrafine wire cutting can be conducted in vertical-, horizontal- or slantwise-wire arrangements. Via some experiments, optimal machining conditions including discharge capacitance, feed rate, wire tension and the appropriate design for the w-EDM device are obtained. Two miniature samples including a micro of Taipei's landmark 101 building and a micro relay are fabricated and the feasibility of the proposed approach is verified. It is confirmed that the ultrafine w-EDM technique using an ultrafine tungsten wire of 13 µm was realized successfully.

Chen, Shun-Tong; Yang, Hong-Ye; Du, Chih-Wei

2009-11-01

88

AN IMPROVED TOPOLOGICAL DESCRIPTOR EDm AND ITS APPLICATION  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english In this paper, on the basis of the topological index EDm derived from ionicity index matrix, improved distance matrix and branching degree matrix, we proposed the new topological descriptor EDm' by introducing the bond angle into hidden hydrogen graph of molecules and using the geometric distance in [...] stead of the sum of bond length between two vertexes. The EDm describes the molecular structure more accurately, and realizes unique characterization to cis-trans isomers. The quantitative structure-property relationship (QSPR) models, with correlation coefficients (R) in the range of 0.984-1.000 for the boiling point (b.p.), the standard enthalpy of formation ( DfHm?), the molar refraction (Rm) and the molar volume (Vm) of some cis-trans isomers for alkenes, are subsequently developed by index EDm'. Moreover, the good stability and predictive ability of the models were demonstrated by LOO (leave-one-out) method and RSP (random sampling prediction) method, which further manifests the index EDm has high potential of wide applications in QSPR study.

NIE, CHANGMING; WU, YAXIN; WU, RONGYAN; WEN, SONGNIAN.

89

AN IMPROVED TOPOLOGICAL DESCRIPTOR EDm AND ITS APPLICATION  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, on the basis of the topological index EDm derived from ionicity index matrix, improved distance matrix and branching degree matrix, we proposed the new topological descriptor EDm' by introducing the bond angle into hidden hydrogen graph of molecules and using the geometric distance instead of the sum of bond length between two vertexes. The EDm describes the molecular structure more accurately, and realizes unique characterization to cis-trans isomers. The quantitative structure-property relationship (QSPR models, with correlation coefficients (R in the range of 0.984-1.000 for the boiling point (b.p., the standard enthalpy of formation ( DfHm?, the molar refraction (Rm and the molar volume (Vm of some cis-trans isomers for alkenes, are subsequently developed by index EDm'. Moreover, the good stability and predictive ability of the models were demonstrated by LOO (leave-one-out method and RSP (random sampling prediction method, which further manifests the index EDm has high potential of wide applications in QSPR study.

CHANGMING NIE

2012-03-01

90

Hybrid micromachining using a nanosecond pulsed laser and micro EDM  

Science.gov (United States)

Micro electrical discharge machining (micro EDM) is a well-known precise machining process that achieves micro structures of excellent quality for any conductive material. However, the slow machining speed and high tool wear are main drawbacks of this process. Though the use of deionized water instead of kerosene as a dielectric fluid can reduce the tool wear and increase the machine speed, the material removal rate (MRR) is still low. In contrast, laser ablation using a nanosecond pulsed laser is a fast and non-wear machining process but achieves micro figures of rather low quality. Therefore, the integration of these two processes can overcome the respective disadvantages. This paper reports a hybrid process of a nanosecond pulsed laser and micro EDM for micromachining. A novel hybrid micromachining system that combines the two discrete machining processes is introduced. Then, the feasibility and characteristics of the hybrid machining process are investigated compared to conventional EDM and laser ablation. It is verified experimentally that the machining time can be effectively reduced in both EDM drilling and milling by rapid laser pre-machining prior to micro EDM. Finally, some examples of complicated 3D micro structures fabricated by the hybrid process are shown.

Kim, Sanha; Kim, Bo Hyun; Chung, Do Kwan; Shin, Hong Shik; Chu, Chong Nam

2010-01-01

91

Study of an ultrafine w-EDM technique  

International Nuclear Information System (INIS)

A precision ultrafine w-EDM (wire electrical discharge machining) technique specifically for machining intricate parts and structures is developed in this paper. A thumb-sized and versatile w-EDM device equipped with a complete control system for wire tension (ultrafine tungsten wire of 13 µm diameter) is designed and employed for the study of ultrafine w-EDM. The tension of the wire electrode is controlled by magnetic repulsive force to steady the wire during machining. Ultrafine wire cutting can be conducted in vertical-, horizontal- or slantwise-wire arrangements. Via some experiments, optimal machining conditions including discharge capacitance, feed rate, wire tension and the appropriate design for the w-EDM device are obtained. Two miniature samples including a micro of Taipei's landmark 101 building and a micro relay are fabricated and the feasibility of the proposed approach is verified. It is confirmed that the ultrafine w-EDM technique using an ultrafine tungsten wire of 13 µm was realized successfully

2009-11-01

92

Surface finishing of micro-EDM holes using deionized water  

International Nuclear Information System (INIS)

In this paper, with the use of deionized water, a finishing process of micro hole surfaces processed by micro electrical discharge machining (micro-EDM) is investigated. A micro hole is machined by micro-EDM using deionized water as a dielectric fluid. The inner surface of the hole is finished successfully via electrochemical dissolution in deionized water. The effects of finishing conditions such as the resistivity of deionized water, the voltage, the tool rotation and the finishing time on the surface quality and accuracy of the shape were investigated. After a finishing process using deionized water with a resistivity of 2 M? cm, a voltage of 80 V, a tool rotation of 1200 rpm and a finishing time of 6 min, the surface roughness was reduced considerably from 0.225 µm Ra after micro-EDM to 0.066 µm Ra

2009-04-01

93

Surface finishing of micro-EDM holes using deionized water  

Science.gov (United States)

In this paper, with the use of deionized water, a finishing process of micro hole surfaces processed by micro electrical discharge machining (micro-EDM) is investigated. A micro hole is machined by micro-EDM using deionized water as a dielectric fluid. The inner surface of the hole is finished successfully via electrochemical dissolution in deionized water. The effects of finishing conditions such as the resistivity of deionized water, the voltage, the tool rotation and the finishing time on the surface quality and accuracy of the shape were investigated. After a finishing process using deionized water with a resistivity of 2 M? cm, a voltage of 80 V, a tool rotation of 1200 rpm and a finishing time of 6 min, the surface roughness was reduced considerably from 0.225 µm Ra after micro-EDM to 0.066 µm Ra.

Chung, Do Kwan; Shin, Hong Shik; Kim, Bo Hyun; Park, Min Soo; Chu, Chong Nam

2009-04-01

94

Empirical Modeling of EDM Parameters Using Grey Relational Analysis  

Directory of Open Access Journals (Sweden)

Full Text Available Optimization of multi criteria problems is a great need of producers to product precision parts with low costs. Many methods such as Taguchi and Response Surface Methodology have been employed for optimization of EDM process. However there are few researches involve the optimization of multi-response problem in EDM process. The attempt of this paper is to optimize multiple performance characteristics of EDM process using Grey relational analysis based on Taguchi orthogonal array. The response table and response graph for each level of the machining parameters is obtained and optimal levels of machining parameters including pulse on time, discharge current, discharge voltage and duty factor are found. The multiple performance characteristics including material removal rate, electrode wear ratio and surface roughness is considered.

A. Doniavi

2008-01-01

95

EDM and the resulting hydrogen embrittlement of maraging steel  

Science.gov (United States)

The use of electrical discharge machining (EDM), or spark erosion as it is sometimes called, introduces hydrogen into maraging steel 250 such that brittle fracture surfaces result from embrittlement accelerated by slow-strain-rate tensile tests. Brittle fracture features indicate potential premature failure due to hydrogen embrittlement. Experimental control was provided by test specimens machined by abrasive waterjet, a machining technique that does not evolve hydrogen as a part of the machining process. Hydrogen concentration measurements indicate the hydrogen concentration of specimens fabricated by EDM is approximately 0.5 ppm, while that of specimens machined by abrasive waterjet is approximately 0.1 ppm. On the basis of constant-load tests, the time to failure of test specimens machined by EDM and loaded to 50% of the yield strength is estimated to be a minimum of 30 years.

Quick, Terrence M.

1993-10-01

96

Searches for double ?+, ?+/EC and double electron-capture decays  

International Nuclear Information System (INIS)

Searches have been made for the ?+/EC and EC/EC decays of 58Ni and for the ?+?+, ?+/EC, and EC/EC decays of 106Cd. No positive evidence for any of these decays has been found. We have established lower limits on the half lives of 58Ni and 106Cd against such decays approximately 200 times and 4 times greater, respectively, than previous limits. 22 references

1984-01-01

97

The Cold Dark Matter Search test stand warm electronics card  

Energy Technology Data Exchange (ETDEWEB)

A card which does the signal processing for four SQUID amplifiers and two charge sensitive channels is described. The card performs the same functions as is presently done with two custom 9U x 280mm Eurocard modules, a commercial multi-channel VME digitizer, a PCI to GPIB interface, a PCI to VME interface and a custom built linear power supply. By integrating these functions onto a single card and using the power over Ethernet standard, the infrastructure requirements for instrumenting a Cold Dark Matter Search (CDMS) detector test stand are significantly reduced.

Hines, Bruce; /Colorado U., Denver; Hansen, Sten; /Fermilab; Huber, Martin; /Colorado U., Denver; Kiper, Terry; /Fermilab; Rau, Wolfgang; /Queen' s U., Kingston; Saab, Tarek; /Florida U.; Seitz, Dennis; Sundqvist, Kyle; /UC, Berkeley; Mandic, Vuk; /Minnesota U.

2010-11-01

98

A New Method For A Sensitive Deuteron EDM Experiment  

CERN Document Server

In this paper a new method is presented for particles in storage rings which could reach a statistical sensitivity of 10**(-27) e cm for the deuteron EDM. This implies an improvement of two orders of magnitude over the present best limits on the T-odd nuclear forces ksi parameter.

Semertzidis, Y K; Auzinsh, M; Balakin, V; Bazhan, A; Bennett, G W; Carey, R M; Cushman, P B; Debevec, P T; Dudnikov, A; Farley, F J M; Hertzog, D W; Iwasaki, M; Jungmann, Klaus; Kawall, D; Khazin, B I; Khriplovich, I B; Kirk, B; Kuno, Y; Lazarus, D M; Leipuner, L B; Logashenko, V; Lynch, K R; Marciano, W J; McNabb, R; Meng, W; Miller, J P; Morse, W M; Onderwater, Gerco; Orlov, Yu F; Ozben, C S; Prig, R; Rescia, S; Roberts, B L; Shafer-Ray, N; Silenko, A; Stephenson, E J; Yoshimura, K

2003-01-01

99

Search for multiple electron scattering sequences in simple systems  

International Nuclear Information System (INIS)

Complete text of publication follows. Double differential spectra of electrons ejected in ion-atom or ion-solid collisions are in the focus of general interest for a long time. These spectra are relatively easy to measure, and they show many fine details relevant for the collisions dynamics. In the past decade special effort has been devoted to understand the high energy part of the electron spectra. Significantly enhanced emission of fast electrons far above the so-called binary encounter energy was observed in both ion-atom and ion-solid collisions. In some cases, fast electrons have been identified from double, triple and quadruple scattering by the projectile and target cores. The ejected electron gains energy in every encounter with the projectile in such processes. This mechanism is often referred to as Fermi-shuttle acceleration. Most of the experiments were performed with dressed heavy projectiles and heavy target atoms, where the cross section is large enough for observing multiple scattering processes. No quantum calculations were possible at such complexity, only classical trajectory Monte-Carlo (CTMC) calculations have been performed for modeling these collisions. Surprisingly, quantitative agreement has been found for many collision systems. Moreover, the analysis of the classical particle trajectories allows one to identify multiple scattering events in the classical sense. The aim of this work is to study the process for simpler collision systems, which can be handled by both classical and quantum calculations. The relevant cross sections might be too small to be measured, but they can be identified and compared in classical and quantum calculations. In the present work, as a first step, we apply the CTMC method for 25 keV He2+ + H collisions at selected impact parameter (b) values. The first results, calculated differential ionization probabilities at b = 0.05 a.u, are shown in Fig. 1. The electron yield above 13.6 eV kinetic energy is expected to originate from multiple scattering. An additional feature is the predicted large enhancement of the electron yield at backward observation angles

2007-01-01

100

The search for permanent electric dipole moments  

Energy Technology Data Exchange (ETDEWEB)

Permanent electric dipole moments (EDMs) of fundamental systems with spin - particles, nuclei, atoms or molecules violate parity and time reversal invariance. Invoking the CPT theorem, time reversal violation implies CP violation. Although CP-violation is implemented in the standard electro-weak theory, EDM generated this way remain undetectably small. However, this CP-violation also appears to fail explaining the observed baryon asymmetry of our universe. Extensions of the standard theory usually include new sources of CP violation and often predict sizeable EDMs. EDM searches in different systems are complementary and various efforts worldwide are underway and no finite value has been established yet. The prototype of an EDM search is the pursuit of the EDM of the neutron. It has the longest history and at the same time is at the forefront of present research. The talk aims at giving an overview of the field with emphasis on our efforts within an international collaboration at PSI, nedm.web.psi.ch.

Kirch, Klaus [PSI-Villigen - ETH Zürich

2013-02-13

 
 
 
 
101

The fabrication of a micro-spiral structure using EDM deposition in the air  

International Nuclear Information System (INIS)

A novel micromachining method to deposit a micro-3D spiral structure in air using electrical discharge machining (EDM) with a brass electrode was presented. During the deposition process, a 3D spiral structure is obtained only by the feed of the z-axis in the vertical direction. Furthermore, the obtained structure can be formed and repeated stably even in the upside-down direction under a gravity environment. It is seen that the material components of a micro-spiral structure are almost the same as those of an electrode by the energy spectrum analysis of a micro-spiral structure. According to scanning electron microscope photographs, the micro-spiral appears to feature a layered material organism structure and has compact bonding with the body material. In order to understand the forming mechanism of this kind of micro-spiral structure, simulation analysis is conducted. The track of the deposition particles can be obtained by simulation, which determines the shape of the deposited structure. According to the simulation results, the track of the deposition particles is consistent with that of EDM experiments. It is further found that the distribution of the electromagnetic field in a discharge channel has an important influence on the deposited structure and the track of the deposition particles

2008-03-01

102

The fabrication of a micro-spiral structure using EDM deposition in the air  

Science.gov (United States)

A novel micromachining method to deposit a micro-3D spiral structure in air using electrical discharge machining (EDM) with a brass electrode was presented. During the deposition process, a 3D spiral structure is obtained only by the feed of the z-axis in the vertical direction. Furthermore, the obtained structure can be formed and repeated stably even in the upside-down direction under a gravity environment. It is seen that the material components of a micro-spiral structure are almost the same as those of an electrode by the energy spectrum analysis of a micro-spiral structure. According to scanning electron microscope photographs, the micro-spiral appears to feature a layered material organism structure and has compact bonding with the body material. In order to understand the forming mechanism of this kind of micro-spiral structure, simulation analysis is conducted. The track of the deposition particles can be obtained by simulation, which determines the shape of the deposited structure. According to the simulation results, the track of the deposition particles is consistent with that of EDM experiments. It is further found that the distribution of the electromagnetic field in a discharge channel has an important influence on the deposited structure and the track of the deposition particles.

Chi, Guanxin; Wang, Zhenlong; Xiao, K.; Cui, Jingzhi; Jin, Baidong

2008-03-01

103

Co-option of EDM2 to distinct regulatory modules in Arabidopsis thaliana development  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Strong immunity of plants to pathogenic microorganisms is often mediated by highly specific mechanisms of non-self recognition that are dependent on disease resistance (R genes. The Arabidopsis thaliana protein EDM2 is required for immunity mediated by the R gene RPP7. EDM2 is nuclear localized and contains typical features of transcriptional and epigenetic regulators. In addition, to its role in immunity, EDM2 plays also a role in promoting floral transition. This developmental function of EDM2, but not its role in RPP7-mediated disease resistance, seems to involve the protein kinase WNK8, which physically interacts with EDM2 in nuclei. Results Here we report that EDM2 affects additional developmental processes which include the formation of leaf pavement cells and leaf expansion as well as the development of morphological features related to vegetative phase change. EDM2 has a promoting effect of each of these processes. While WNK8 seems not to exhibit any vegetative phase change-related function, it has a promoting effect on the development of leaf pavement cells and leaf expansion. Microarray data further support regulatory interactions between WNK8 and EDM2. The fact that the effects of EDM2 and WNK8 on leaf pavement cell formation and leaf expansion are co-directional, while WNK8 counteracts the promoting effect of EDM2 on floral transition, is surprising and suggests that WNK8 can modulate the activity of EDM2. Conclusion We propose that EDM2 has been co-opted to distinct regulatory modules controlling a set of different processes in plant immunity and development. WNK8 appears to modulate some functions of EDM2.

Tsuchiya Tokuji

2010-09-01

104

Hedonic and utilitarian search for electronic word-of-mouth and implications on purchase value  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Online information search is often seen as a highly utilitarian task but consumers' increasingly diverse ways of using the Web have brought forth more hedonic information search patterns. At the same time, the impact of electronic word-of-mouth (eWOM) on consumer purchase decisions is increasing. The purpose of this study is to investigate the differences between hedonic and utilitarian eWOM search patterns in the light of purchase value. Using survey data from 1660 customers of two travel ag...

Po?yry, Essi

2011-01-01

105

Laser irradiated enhancement of the atomic electron capture rate in search of new physics  

International Nuclear Information System (INIS)

Electron capture processes are important in the search for new physics. In this context, a high capture rate is desired. We investigate the possibility of enhancing the electron capture rate by irradiating laser beam to 'atom'. The possibility of such enhancement can be understood as a consequence of an enhancement of the electron wave function at the origin, ?(0), through an increased effective mass of the electron. We find that an order of magnitude enhancement can be realized by using a laser with intensity on the order of 1010 W/mm2 and a photon energy on the order of 10-3 eV. (author)

2007-03-01

106

Energy Data Management (EDM) in a liberalised energy market  

International Nuclear Information System (INIS)

This article discusses the role of Energy Data Management (EDM) in a liberalised Swiss energy market in the light of increasing international dynamics in this area. The requirements placed on such EDM systems are reviewed and the changes necessary in the structures and processes of electricity supply organisations are discussed. A possible design for future software systems is presented. Such systems have to be flexible enough to cover various structural possibilities as Swiss legislation on the subject has not yet been passed. The handling of data on energy-flow balances when third-party power is transferred in shared mains systems is discussed and scheduling aspects of power generation and transmission are looked at. The billing of power to customers with a free choice of supplier is looked at, as is the situation involving utilities that supply not only electricity but gas, district heating and water too

2004-01-01

107

Studies for Obtaining a Small Holle, Rapid EDM Drilling Machine  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper studies the obtaining of an experimental rapid drilling machine, through EDM process for small holes. The best parameters such as peak current, pulse frequency, duty factor and electrode rotation speed were studied for best machining characteristics. An electrolytic copper rod 0.8 mm diameter was selected as a tool electrode. The experiments generate output responses such as maximum material removal rate (MRR) and the dependence with peak current, duty factor and electrode rotation...

Mihai Simon; Lucian Grama

2011-01-01

108

“Mathematical modeling of EDM hole drilling using response surface methodology”  

Directory of Open Access Journals (Sweden)

Full Text Available This paper reports an experimental investigation of EDM drilling of Ø2 mm holes on Inconel 718using brass electrode. The effect of process parameters (discharge current, pulse on and off times, andcapacitance on process outputs (material removal rate and electrode wear rate was determined based onminimum number of experiments. The mathematical modeling of process has been done using response surfacemethodology. The results show that the developed model can achieve reliable prediction of experimentalresults within acceptable accuracy

N. G. Alvi

2012-05-01

109

Electronic Book Usage Patterns as Observed at an Academic Library: Searches and Viewings  

Directory of Open Access Journals (Sweden)

Full Text Available In 2009, e-book usage statistics were evaluated at Laurentian University, Canada, to provide a better understanding in how the e-book collection has been utilized as well as to give direction for further collection development. The number of e-books, the number of viewings and the number of searches were examined. The size of the collection grew from a single book in 2002 to more than 60,000 in 2008. The pattern of purchase varied from that of bulk purchasing of large e-book collections to a more selective purchase from 2005 to 2007 and then back to that of bulk purchasing in 2008. Both viewings and searches have increased from year to year at a greater pace than the size e-book collection. The number of searches also appeared to provide a viable means to measure the use of an e-book collection rather than relying entirely on viewings or downloads. Ratios were calculated when comparing viewings and searches to the size of the collection. The largest viewings per e-book and searches per e-book ratios were observed in those years when purchasing was done more selectively. It is also clear that the electronic reference collection has seen far greater use then the electronic monographs. Furthermore, usage of electronic monographs also appeared to be directly proportional to the size of the collection.

Alain R. Lamothe

2010-07-01

110

Optimizing the Machining Parameters of Micro-EDM for Inconel 718  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper aims to study on the feasibility of micron size hole manufacturing using micro Electric Discharge Machining (Micro-EDM). Main and auxiliary unit of the micro-EDM machine tool and their functions are described in some detail. The technological and electrical parameters that are effective in Micro-EDM are stated explicitly. Geometry of the machined micro-holes and resolidified material around the hole entrance are observed. Several descriptive pictures, obtained by Scanning Ele...

Manikandan, R.; Venkatesan, R.

2012-01-01

111

Enhancement of the electron electric dipole moment in gadolinium garnets  

CERN Multimedia

Effects caused by the electron electric dipole moment (EDM) in gadolinium garnets are considered. Experimental studies of these effects could improve current upper limit on the electron EDM by several orders of magnitude. We suggest a consistent theoretical model and perform calculations of observable effects in gadolinium gallium garnet and gadolinium iron garnet. Our calculation accounts for both direct and exchange diagrams.

Mukhamedjanov, T N; Sushkov, O P

2003-01-01

112

Search of non-standard strong gravity at nuclear scale using electron spin geodetic precession  

Directory of Open Access Journals (Sweden)

Full Text Available The MTV-G project was started in 2011 to explore a strong gravitational field at a nuclear scale in an electron double scattering experiment, utilizing an experimental technique of the MTV experiment, which searches a electron’s T-Violating transverse polarization in nuclear beta decay at TRIUMF-ISAC. In addition to this new experiment, we have also performed a re-analysis of spectroscopic data of exotic atoms, in a gravitational point of view. From these two studies, we set new constraints on possible new Yukawa interaction at sub-mm scale, as a test of gravitational inverse square law.

Tanaka Saki

2014-03-01

113

Analysis of Different Tool Material On MRR and Surface Roughness of Mild Steel In EDM  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, experiments were performed todetermine parameters effecting surface roughness (SRalong with structural analysis of surfaces with respect tomaterial removal parameters. Experimental work wasconducted on Mildl steel with copper, brass and graphiteas tool electrodes with kerosene oil as dielectric fluid.The data compiled during experimentation has beenused to yield responses in respect of material removalrate (MRR and SR. Detailed analysis of structuralfeatures of machined surface was done by usingScanning Electron Microscope (SEM and opticalmicroscope to understand the mode of heat affected zone(HAZ, which alternatively affects structure of machinedworkpiece and hence tool life. While investigatingelectric discharge machining (EDM surface bymicrographs, it was observed that molten mass has beenremoved from surface as ligaments and sheets. In somecases, it is removed as chunks, which being in moltenstate stuck to surface. All three specimens machined bydifferent electrodes showed different pattern of HAZs.

Mr. V.D.Patel*, Mr. U.J. Patel

114

Electron electric dipole moment experiment using electric-fieldquantized slow cesium atoms  

Energy Technology Data Exchange (ETDEWEB)

A proof-of-principle electron electric dipole moment (e-EDM)experiment using slow cesium atoms, nulled magnetic fields, and electricfield quantization has been performed. With the ambient magnetic fieldsseen by the atoms reduced to less than 200 pT, an electric field of 6MV/m lifts the degeneracy between states of unequal lbar mF rbar and,along with the low (approximately 3 m/s) velocity, suppresses thesystematic effect from the motional magnetic field. The low velocity andsmall residual magnetic field have made it possible to induce transitionsbetween states and to perform state preparation, analysis, and detectionin regions free of applied static magnetic and electric fields. Thisexperiment demonstrates techniques that may be used to improve the e-EDMlimit by two orders of magnitude, but it is not in itself a sensitivee-EDM search, mostly due to limitations of the laser system.

Amini, Jason M.; Munger Jr., Charles T.; Gould, Harvey.

2007-04-05

115

Monitoring local crustal movements using high precision GPS network and EDM baseline  

Science.gov (United States)

Finnish Geodetic Institute (FGI) established in a co-operation with Posiva Ltd. high precision GPS networks at Olkiluoto, Kivetty and Romuvaara in 1994-1995. The goal of the work is to study local crustal deformations at the areas, which were selected as candidates for a disposal of spent nuclear fuel used in Finland. The studies are now concentrated at Olkiluoto, because the Government and the Parliament have ratified the positive policy decision that makes it possible to establish the final disposal at Olkiluoto. The GPS network at Olkiluoto includes ten reinforced concrete pillars located in different geological blocks. The FGI has observed the network semiannually since 1995. The GPS observations were made in 24 h sessions with Ashtech Z-12 GPS receivers equipped with Ashtech Dorne Margolin Choke Ring antennas. The computations were made with Bernese GPS software using the L1 and L2 frequencies and the ionosphere models. According to the 14 measurements campaigns the largest baselines change rates are about 0.5 mm ± 0.1-0.2 mm per year. We have noticed that some GPS sessions yield baseline lengths, which are systematically longer than the mean of all campaigns. The systematic error is most probably due to the ionosphere modeling. In order to solve this scaling problem we established a 511 m baseline for electronic distance measurements (EDM) between two pillars in the spring 2002. We will measure the distance between these stations with Mekometer 5000 during the GPS measurement campaigns. Two Mekometer measurements were performed in 2002. The differences between the GPS and the EDM measurements are few tenth of millimeter. More measurement campaigns are needed to determine possible crustal movements at the Olkiluoto investigation area. GPS observations and electronic distance measurements will be continued semiannually.

Ahola, J.; Ollikainen, M.

2003-04-01

116

A search for excited fermions in electron-proton collisions at HERA  

International Nuclear Information System (INIS)

A search for excited states of the standard model fermions was performed using the ZEUS detector at the HERA electron-proton collider, operating at a centre of mass enery of 296 GeV. In a sample corresponding to an integrated luminosity of 0.55 pb-1, no evidence was found for any resonant state decaying into final states composed of a fermion and a gauge boson. Limits on the coupling strength times branching ratio of excited fermions are presented for masses between 50 GeV and 250 GeV, extending previous search regions significantly. (orig.)

1994-01-01

117

Search for a permanent electric-dipole moment using atomic indium  

International Nuclear Information System (INIS)

We propose indium (In) as a possible candidate for observing the permanent electric dipole moment (EDM) arising from violations of parity (P) and time-reversal (T) symmetries. This atom has been laser cooled and therefore the measurement of its EDM has the potential of improving on the current best EDM limit for a paramagnetic atom, which comes from thallium. We report the results of our calculations of the EDM enhancement factor due to the electron EDM and the ratio of the atomic EDM to the electron-nucleus scalar-pseudoscalar (S-PS) interaction coupling constant in In within the framework of the relativistic coupled cluster theory. It might be possible to get new limits for the electron EDM and the S-PS CP-violating coupling constant by combining the results of our calculations with the measured value of the EDM of In when it is available. These limits could have important implications for the standard model (SM) of particle physics.

2011-09-01

118

Combined Sensor Package COMARS+ for Measuring Aerothermal and Radiation Loads on the Exomars EDM Capsule Back Cover  

Science.gov (United States)

Based on the former flight instrumentation experience combined aerothermal sensor package COMARS+ has been developed to perform radiative and convective heat flux measurements on the EDM back cover TPS of ExoMars EDM flight in 2016.

Guelhan, A.; Siebe, F.; Thiele, T.

2014-06-01

119

The Computational Complexity of Orientation Search Problems in Cryo-Electron Microscopy  

CERN Multimedia

In this paper we study the problem of determining three-dimensional orientations for noisy projections of randomly oriented identical particles. The problem is of central importance in the tomographic reconstruction of the density map of macromolecular complexes from electron microscope images and it has been studied intensively for more than 30 years. We analyze the computational complexity of the orientation problem and show that while several variants of the problem are $NP$-hard, inapproximable and fixed-parameter intractable, some restrictions are polynomial-time approximable within a constant factor or even solvable in logarithmic space. The orientation search problem is formalized as a constrained line arrangement problem that is of independent interest. The negative complexity results give a partial justification for the heuristic methods used in orientation search, and the positive complexity results on the orientation search have some positive implications also to the problem of finding functionally...

Mielik"ainen, T; Ukkonen, E; Mielik\\"ainen, Taneli; Ravantti, Janne; Ukkonen, Esko

2004-01-01

120

Positional accuracy study of a micro-EDM machine  

Science.gov (United States)

Micro-electrodischarge machining is used to machine small features such as holes, cavities and slots with high aspect ratios in electrically-conductive materials for various applications including medical implants, printing devices, dies and spray nozzles. In this study, the positional accuracy of a micro-EDM machine was assessed while simulating the machining of an array of holes. The measurement involved the use of a diffraction grid plate and non-contact scanning head. This enabled various conclusions to be drawn as to the relative deviations experienced when machining small features such as (phi) 50 micrometers holes.

Almond, Heather J.; Bhogal, Jagmohan; Allen, David M.

1999-03-01

 
 
 
 
121

Temperature Distribution Measurement in EDM Arc Plasma Using Spectroscopy  

Science.gov (United States)

This paper describes the measurement of temperature distribution in EDM arc plasma using spectroscopic analysis. The temperature distribution measurement was achieved by using a lens system to magnify the image of the plasma and a mask to limit the plasma region to be observed. The fluxes of two different wavelength spectra radiated from the arc plasma were measured simultaneously with optical fibers and photomultipliers, after which the temperature distribution was computed from the radiant fluxes using the line pair method and Ablel's inversion. Also, the influences of machining conditions, such as electrode shape, gap distance and discharge current, on the temperature distribution were investigated.

Natsu, Wataru; Ojima, Satoyuki; Kobayashi, Teruki; Kunieda, Masanori

122

Studies for obtaining a small holle, rapid edm drilling machine  

Directory of Open Access Journals (Sweden)

Full Text Available This paper studies the obtaining of an experimental rapid drilling machine, through EDM process for small holes. The best parameters such as peak current, pulse frequency, duty factor and electrode rotation speed were studied for best machining characteristics. An electrolytic copper rod 0.8 mm diameter was selected as a tool electrode. The experiments generate output responses such as maximum material removal rate (MRR and the dependence with peak current, duty factor and Electrode rotation, parameters. Finally, parameters were optimized for maximum MRR with desired surface roughness value and used for sizing the component for a better small rapid drilling machine.

Mihai ?imon

2011-12-01

123

Studies for Obtaining a Small Holle, Rapid EDM Drilling Machine  

Directory of Open Access Journals (Sweden)

Full Text Available This paper studies the obtaining of an experimental rapid drilling machine, through EDM process for small holes. The best parameters such as peak current, pulse frequency, duty factor and electrode rotation speed were studied for best machining characteristics. An electrolytic copper rod 0.8 mm diameter was selected as a tool electrode. The experiments generate output responses such as maximum material removal rate (MRR and the dependence with peak current, duty factor and electrode rotation, parameters. Finally, parameters were optimized for maximum MRR with desired surface roughness value and used for sizing the component for a better small rapid drilling machine.

Mihai Simon

2011-11-01

124

Vertical EDM (electric discharge machining) using modular programming  

Energy Technology Data Exchange (ETDEWEB)

The usual function of computer numerically controlled (CNC) machining programs is to specify a sequence of machining operations. When CNC is applied to electric discharge machining (EDM), the possibilities and needs are much greater. This paper describes a modular system of programming in which various functions are carried out by subroutines contained in the controller memory. The subroutines are made more versatile by using variables. Such functions as orbiting, cavity inspection, electrode wear measurement and compensation, and multiple cavities are possible. 3 refs., 9 figs.

Fuller, J.E.

1989-01-01

125

High Voltage Test Apparatus for a Neutron EDM Experiment and Lower Limit on the Dielectric Strength of Liquid Helium at Large Volumes  

CERN Document Server

A new search for a permanent electric dipole moment (EDM) of the neutron is underway using ultracold neutrons produced and held in a bath of superfluid helium. Attaining the target sensitivity requires maintaining an electric field of several tens of kilovolts per centimeter across the experimental cell, which is nominally 7.5 cm wide and will contain about 4 liters of superfluid. The electrical properties of liquid helium are expected to be sufficient to meet the design goals, but little is known about these properties for volumes and electrode spacings appropriate to the EDM experiment. Furthermore, direct application of the necessary voltages from an external source to the experimental test cell is impractical. An apparatus to amplify voltages in the liquid helium environment and to test the electrical properties of the liquid for large volumes and electrode spacings has been constructed. The device consists of a large-area parallel plate capacitor immersed in a 200 liter liquid helium dewar. Preliminary r...

Long, J C; Boissevain, J G; Clark, D J; Cooper, M D; Gómez, J J; Lamoreaux, S K; Mischke, R E; Penttila, S I

2006-01-01

126

Wire EDM Fatigue Study with Application to Multi-Lug Breech Mechanisms.  

Science.gov (United States)

A fatigue study was conducted to evaluate wire electrical discharge machining (EDM) as a manufacturing method for the production of the intricate lug geometry on multi-lug breech mechanisms. The wire EDM process produces a thin surface layer of recast mat...

V. J. Olmstead S. Tauscher

1997-01-01

127

Numerical prediction of heat affected layer in the EDM of aeronautical alloys  

Science.gov (United States)

Electrical discharge machining is a popular non-traditional machining process, optimum for accurate machining of complex geometries in hard materials. EDM has been used for decades for machining pieces for the aeronautical industry, but surface integrity, and consequently the reliability of the machined parts have been questioned for long time due to the thermal nature of this machining process. In recent years, efforts have been put on modeling of the EDM process, being thermal modeling of the process one promising alternative. In a previous publication an original model of the EDM process was presented and it was used to predict material removal rate and surface finish for the EDM of steel. In the present article the capability of that modeling tool to characterize discharge properties and to predict recast layer distribution when EDMing an aeronautical alloy will be analyzed. EDM process of Inconel 718 has been studied and discharge properties have been obtained for four different EDM regimes. The capability of the model to reflect the behavior of more energetic regimes is discussed. Gathered information has been used to simulate the evolution of the recast layer generation process. Obtained results have been validated comparing them with experimental measurements, revealing a good correlation between predictions and experimental data. Finally, energetic efficiency of the discharge process has been simulated for the adjusted EDM regimes.

Izquierdo, B.; Plaza, S.; Sánchez, J. A.; Pombo, I.; Ortega, N.

2012-10-01

128

Neutrino scattering on atomic electrons in searches for the neutrino magnetic moment.  

Science.gov (United States)

The scattering of a neutrino on atomic electrons is considered in the situation where the energy transferred to the electrons is comparable to the characteristic atomic energies, as relevant to the current experimental search for the neutrino magnetic moment. The process is induced by the standard electroweak interaction as well as by the possible neutrino magnetic moment. Quantum-mechanical sum rules are derived for the inclusive cross section at a fixed energy deposited in the atomic system, and it is shown that the differential over the energy transfer cross section is given, modulo very small corrections, by the same expression as for free electrons, once all possible final states of the electronic system are taken into account. Thus, the atomic effects effectively cancel in the inclusive process. PMID:21231219

Voloshin, M B

2010-11-12

129

Neutrino scattering on atomic electrons in searches for neutrino magnetic moment  

CERN Document Server

The scattering of a neutrino on atomic electrons is considered in the situation where the energy transferred to the electrons is comparable to the characteristic atomic energies, as relevant for the current experimental search for neutrino magnetic moment. The process is contributed by the standard electroweak interaction as well as by the possible neutrino magnetic moment. Quantum mechanical sum rules are derived for the inclusive cross section at a fixed energy deposited in the atomic system, and it is shown that the differential over the energy transfer cross section is given, modulo very small corrections, by the same expression as for free electrons, once all possible final states of the electronic system are taken into account. Thus the atomic effects effectively cancel in the inclusive process.

Voloshin, M B

2010-01-01

130

Search for light-speed anisotropies using Compton scattering of high-energy electrons  

CERN Document Server

Based on the high sensitivity of Compton scattering off ultra relativistic electrons, the possibility of anisotropies in the speed of light is investigated. The result discussed in this contribution is based on the gamma-ray beam of the ESRF's GRAAL facility (Grenoble, France) and the search for sidereal variations in the energy of the Compton-edge photons. The absence of oscillations yields the two-sided limit of 1.6 x 10^{-14} at 95 % confidence level on a combination of photon and electron coefficients of the minimal Standard Model Extension (mSME). This new constraint provides an improvement over previous bounds by one order of magnitude.

Rebreyend, Dominique

2010-01-01

131

Search for Light-Speed Anisotropies Using Compton Scattering of High-Energy Electrons  

Science.gov (United States)

Based on the high sensitivity of Compton scattering off ultra relativistic electrons, the possibility of anisotropies in the speed of light is investigated. The result discussed in this contribution is based on the ?-ray beam of the ESRF's GRAAL facility (Grenoble, France) and the search for sidereal variations in the energy of the Compton-edge photons. The absence of oscillations yields the two-sided limit of 1.6 × 10-14 at 95% confidence level on a combination of photon and electron coefficients of the minimal Standard-Model Extension (mSME). This new constraint provides an improvement over previous bounds by one order of magnitude.

Rebreyend, D.; Bocquet, J.-P.; Moricciani, D.; Bellini, V.; Beretta, M.; Casano, L.; Dangelo, A.; di Salvo, R.; Fantini, A.; Franco, D.; Gervino, G.; Ghio, F.; Giardina, G.; Girolami, B.; Giusa, A.; Gurzadyan, V. G.; Kashin, A.; Knyazyan, S.; Lapik, A.; Lehnert, R.; Levi Sandri, P.; Lleres, A.; Mammoliti, F.; Mandaglio, G.; Manganaro, M.; Margarian, A.; Mehrabyan, S.; Messi, R.; Nedorezov, V.; Perrin, C.; Randieri, C.; Rudnev, N.; Russo, G.; Schaerf, C.; Sperduto, M.-L.; Sutera, M.-C.; Turinge, A.; Vegna, V.

2011-12-01

132

Search of non-standard strong gravity at nuclear scale using electron spin geodetic precession  

Science.gov (United States)

The MTV-G project was started in 2011 to explore a strong gravitational field at a nuclear scale in an electron double scattering experiment, utilizing an experimental technique of the MTV experiment, which searches a electron's T-Violating transverse polarization in nuclear beta decay at TRIUMF-ISAC. In addition to this new experiment, we have also performed a re-analysis of spectroscopic data of exotic atoms, in a gravitational point of view. From these two studies, we set new constraints on possible new Yukawa interaction at sub-mm scale, as a test of gravitational inverse square law.

Tanaka, Saki; Nakaya, Yusuke; Narikawa, Reiya; Ninomiya, Kazufumi; Onishi, Junichi; Pearson, Matthew; Openshaw, Robert; Saiba, Shuntaro; Tanuma, Ryosuke; Totsuka, Yumi; Murata, Jiro

2014-03-01

133

An Electron Antineutrino Disappearance Search Using High-Rate 8Li Production and Decay  

CERN Document Server

This paper introduces a novel, high-intensity source of electron antineutrinos from the production and subsequent decay of 8Li. When paired with an existing ~1 kton scintillator-based detector, this =6.4 MeV source opens a wide range of possible searches for beyond standard model physics via studies of the inverse beta decay interaction. In particular, the experimental design described here has unprecedented sensitivity to electron antineutrino disappearance at $\\Delta m^2\\sim$ 1 eV$^2$ and features the ability to distinguish between the existence of zero, one, and two sterile neutrinos.

Bungau, A; Alonso, J R; Barletta, W; Barlow, R; Bartoszek, L; Calabretta, L; Calanna, A; Campo, D; Conrad, J M; Djurcic, Z; Kamyshkov, Y; Shaevitz, M H; Shimizu, I; Smidt, T; Spitz, J; Wascko, M; Winslow, L A; Yang, J J

2012-01-01

134

Database Search Strategies for Proteomic Data Sets Generated by Electron Capture Dissociation Mass Spectrometry  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Large data sets of electron capture dissociation (ECD) mass spectra from proteomic experiments are rich in information; however, extracting that information in an optimal manner is not straightforward. Protein database search engines currently available are designed for low resolution CID data, from which Fourier transform ion cyclotron resonance (FT-ICR) ECD data differs significantly. ECD mass spectra contain both z-prime and z-dot fragment ions (and c-prime and c-dot); ECD mass spectra con...

2009-01-01

135

Search for Electron Neutrino Appearance in a 250 km Long-baseline Experiment  

CERN Multimedia

We present a search for electron neutrino appearance from accelerator produced muon neutrinos in the K2K long baseline neutrino experiment. One candidate event is found in the data corresponding to an exposure of 4.8*10^19 protons on target. The expected background in the absence of neutrino oscillations is estimated to be 2.4+-0.6 events and is dominated by mis-identification of events from neutral current pi^0 production. We exclude the \

Ahn, M H; Ashie, Y; Bhang, H; Boyd, S; Casper, D; Choi, J H; Fukuda, S; Fukuda, Y; Gran, R; Hara, T; Hasegawa, M; Hasegawa, T; Hayashi, K; Hayato, Y; Hill, J; Ichikawa, A K; Ikeda, A; Inagaki, T; Ishida, T; Ishii, T; Ishitsuka, M; Itow, Y; Iwashita, T; Jang, H I; Jang, J S; Jeon, E J; Joo, K K; Jung, C K; Kajita, T; Kameda, J; Kaneyuki, K; Kato, I; Kearns, E; Kibayashi, A; Kielczewska, D; Kim, B J; Kim, C O; Kim, J Y; Kim, S B; Kobayashi, K; Kobayashi, T; Koshio, Y; Kropp, W R; Learned, J G; Lim, S H; Lim, I T; Maesaka, H; Maruyama, T; Matsuno, S; Mauger, C; McGrew, C; Minamino, A; Mine, S; Miura, M; Miyano, K; Morita, T; Moriyama, S; Nakahata, M; Nakamura, K; Nakano, I; Nakata, F; Nakaya, T; Nakayama, S; Namba, T; Nambu, R; Nishikawa, K; Nishiyama, S; Noda, S; Obayashi, Y; Okada, A; Oyama, Y; Pac, M Y; Park, H; Saji, C; Sakuda, M; Sarrat, A; Sasaki, T; Sasao, N; Scholberg, K; Sekiguchi, M; Sharkey, E; Shiozawa, M; Shiraishi, K K; Smy, M B; Sobel, H W; Stone, J L; Suga, Y; Sulak, L R; Suzuki, A; Suzuki, Y; Takeuchi, Y; Tamura, N; Tanaka, M; Totsuka, Y; Ueda, S; Vagins, M R; Walter, C W; Wang, W; Wilkes, R J; Yamada, S; Yamamoto, S; Yanagisawa, C; Yokoyama, H; Yoo, J; Yoshida, M; Zalipska, J

2004-01-01

136

Full energy photo electron peak position of monitored proportional counter in BESIII drift chamber searched automatically  

International Nuclear Information System (INIS)

By adopting simplex method algorithm, 55Fe 5.9 keV X-ray full energy photo electron peak position searched automatically in monitored proportional counter of BES III drift chamber is reported. Applied simplex method to the monitor proportional counter of BES III drift chamber, it's proved to have a good converge properties and the chamber can be monitored automatically, real-timely and precisely. (authors)

2009-01-01

137

A fatigue study of electrical discharge machine (EDM) strain-gage balance materials  

Science.gov (United States)

A fatigue study was undertaken to determine how much electrical-discharge-machine (EDM) processing affected the fatigue life of balance materials: EDM and regular milling-machine (MM) samples were compared. Simulation of a typical balance stress configuration was devised for the fatigue testing in order to obtain results more closely related to balance situations. The fatigue testing of the EDM and MM specimens has indicated that the EDM technique does indeed reduce the fatigue life of 15-5PH steel, the first balance material tested. This conclusion was based on comparisons of the specimen fatigue lives with theoretical and manufacturer's data. Hence the EDM surface effects are detrimental to the fatigue life of this balance material.

Rhew, Ray D.

1989-01-01

138

An on-line monitoring system for a micro electrical discharge machining (micro-EDM) process  

Science.gov (United States)

A pulse-type discriminating system to monitor the process of micro electrical discharge machining (micro-EDM) is developed and implemented. The specific features are extracted and the pulses from a RC-type power source are classified into normal, effective arc, transient short circuit and complex types. An approach to discriminate the pulse type according to three durations measured at three pre-determined voltage levels of a pulse is proposed. The developed system is verified by using simulated signals. Discrimination of the pulse trains in actual machining processes shows that the pulses are mainly the normal type for micro wire-EDM and micro-EDM milling. The pulse-type distribution varies during the micro-EDM drilling process. The percentage of complex-type pulse increases monotonically with the drilling depth. It starts to drop when the gap condition is seriously deteriorated. Accordingly, an on-line monitoring strategy for the micro-EDM drilling process is proposed.

Liao, Y. S.; Chang, T. Y.; Chuang, T. J.

2008-03-01

139

An on-line monitoring system for a micro electrical discharge machining (micro-EDM) process  

International Nuclear Information System (INIS)

A pulse-type discriminating system to monitor the process of micro electrical discharge machining (micro-EDM) is developed and implemented. The specific features are extracted and the pulses from a RC-type power source are classified into normal, effective arc, transient short circuit and complex types. An approach to discriminate the pulse type according to three durations measured at three pre-determined voltage levels of a pulse is proposed. The developed system is verified by using simulated signals. Discrimination of the pulse trains in actual machining processes shows that the pulses are mainly the normal type for micro wire-EDM and micro-EDM milling. The pulse-type distribution varies during the micro-EDM drilling process. The percentage of complex-type pulse increases monotonically with the drilling depth. It starts to drop when the gap condition is seriously deteriorated. Accordingly, an on-line monitoring strategy for the micro-EDM drilling process is proposed

2008-03-01

140

Development of electronic information search and documentation system to preserve knowledge about fast reactors  

International Nuclear Information System (INIS)

The necessity to preserve the knowledge gained in the process of fast reactors development and operation is quite obvious. For this purpose it is necessary to set up electronic libraries and suitable search systems. All the documents that contain certain information about the objects from the given field of knowledge can be referred to as sources of knowledge, i.e. they are articles, preprints, papers, clarification notes, reports, catalogs and other sources. These sources of knowledge can be found in various places, institutions, archives, etc. Usually they are kept in libraries. These sources can have different forms, e.g. electronic, printed, photo, microfiche, etc. The information about these sources of knowledge is placed in catalogs that make the process of searching for required documents much easier. Catalogs usually have a subject heading identifier, index of authors, index of topics, key words and summaries. In a certain sense, catalogs can be also considered as sources of knowledge. There are a lot of various sources of knowledge and experience in the nuclear industry under the subject of 'Fast Reactors'. All of them are in different states in terms of convenience of their use and even possibility to use this knowledge and experience once again. In the best case these sources are in the form of electronic documents that contain not only the information about certain knowledge and experience but this very knowledge and experience in the digitized electronic form. These types of catalogs are the most suitable and simple for their use. There are libraries where knowledge and experience are only kept as nondigitized images of documents. It is not so convenient to work with this information but still it is quite real to get it. If a catalogs only contains information about knowledge and experience but neither is available in electronic form, then in order to get the access to this information it will be necessary either to digitize it or to get its non-electronic copy (usually, hard copy). But even if the entire scope of information about knowledge and experience is presented in electronic catalogs, nevertheless there will be a certain problem to work with it, as to work with a lot of intangible sources may turn out to be much more time- and labor-consuming than to work with it within a single system. Two problems have to be solved in terms of knowledge preservation. The first one is related to transformation of all the sources into electronic form. The second one is related to effective search for the required information by means of the catalogs available. The first problem can be solved rather easily. All the published sources of knowledge can be scanned and transformed into electronic form. Thus, instead of printed catalogs that contain the information about sources of knowledge there will be electronic catalogs. Though this activity seems rather simple, it is still very labor-and time-consuming, because the number of these sources is tremendous. We cannot say that the first problem can be promptly solved because it will require not only great financial expenses but also significant organizational efforts. To solve the second problem is much more complicated, as currently there are no effective search systems oriented towards a specific field of knowledge that could run in heterogeneous and worldwide search environment. At the same time this problem can be solved much faster than the first one, because in this case we mean the development of a software product independent of any organizational measures. The conditions required to cope with this problem imply the availability of electronic catalogs that contain the information about sources of knowledge and their accessibility in the computer network

2005-02-14

 
 
 
 
141

Database search strategies for proteomic data sets generated by electron capture dissociation mass spectrometry.  

Science.gov (United States)

Large data sets of electron capture dissociation (ECD) mass spectra from proteomic experiments are rich in information; however, extracting that information in an optimal manner is not straightforward. Protein database search engines currently available are designed for low resolution CID data, from which Fourier transform ion cyclotron resonance (FT-ICR) ECD data differs significantly. ECD mass spectra contain both z-prime and z-dot fragment ions (and c-prime and c-dot); ECD mass spectra contain abundant peaks derived from neutral losses from charge-reduced precursor ions; FT-ICR ECD spectra are acquired with a larger precursor m/z isolation window than their low-resolution CID counterparts. Here, we consider three distinct stages of postacquisition analysis: (1) processing of ECD mass spectra prior to the database search; (2) the database search step itself and (3) postsearch processing of results. We demonstrate that each of these steps has an effect on the number of peptides identified, with the postsearch processing of results having the largest effect. We compare two commonly used search engines: Mascot and OMSSA. Using an ECD data set of modest size (3341 mass spectra) from a complex sample (mouse whole cell lysate), we demonstrate that search results can be improved from 630 identifications (19% identification success rate) to 1643 identifications (49% identification success rate). We focus in particular on improving identification rates for doubly charged precursors, which are typically low for ECD fragmentation. We compare our presearch processing algorithm with a similar algorithm recently developed for electron transfer dissociation (ETD) data. PMID:19821632

Sweet, Steve M M; Jones, Andrew W; Cunningham, Debbie L; Heath, John K; Creese, Andrew J; Cooper, Helen J

2009-12-01

142

Characterization of a 1/2-scale prototype magnet at cryogenic temperatures for the SNS nEDM experiment  

Science.gov (United States)

The observation of a permanent electric dipole moment of the neutron at the current level of experimental sensitivity would indicate new physics beyond the Standard Model of particle interactions. In addition, it might also explain the mystery behind the matter-antimatter asymmetry of the Universe. Given these tantalizing implications, a new multi-institutional effort to measure the neutron electric dipole moment (nEDM) using ultra-cold neutrons and polarized ^3He in a bath of superfluid ^4He is currently underway at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The search for the nEDM asks for stringent requirements on the uniformity of the magnetic environment at cryogenic temperatures. We present measurements of the uniformity of a half-scale version of the coil that will be used for the experiment. The measurements are performed while the coil is at a temperature of 90 K. The results are in good agreement with previous room temperature measurements which suggest that magnetic non-uniformities due to thermal contraction are under control.

Perez Galvan, Adrian; Filippone, Bradley

2011-10-01

143

Search for pair production of the scalar top quark in the electron+muon final state  

Energy Technology Data Exchange (ETDEWEB)

We report the result of a search for the pair production of the lightest supersymmetric partner of the top quark ({tilde t}{sub 1}) in p{bar p} collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider corresponding to an integrated luminosity of 5.4 fb{sup -1}. The scalar top quarks are assumed to decay into a b quark, a charged lepton, and a scalar neutrino ({tilde {nu}}), and the search is performed in the electron plus muon final state. No significant excess of events above the standard model prediction is detected, and improved exclusion limits at the 95% C.L. are set in the (M{sub {tilde t}{sub 1}}, M{sub {tilde {nu}}}) mass plane.

Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Alexeev, G.D.; Alkhazov, G.; Altona, A.; Alverson, G.; Alves, G.A.

2010-09-01

144

EDM constraints and CP asymmetries of B processes in supersymmetric models  

International Nuclear Information System (INIS)

We demonstrate that electric dipole moments (EDMs) strongly constrain possible SUSY contributions to the CP asymmetries of B processes; LL and/or RR flavour mixings between second and third generations are severely restricted by the experimental limit on the mercury EDM, and so therefore are their possible contributions to the CP asymmetries of B->?K and B->?'K. We find that SUSY models with dominant LR and RL mixing through non-universal A-terms is the only way to accommodate the apparent deviation of CP asymmetries from those expected in the Standard Model without conflicting with the EDM bounds or with any other experimental results

2005-07-07

145

A miniaturized EDM device suitable to fixing on a robot  

Science.gov (United States)

A miniaturized EDM (Electro Discharge Machining) device has been designed which is suitable to fixing on robot, and the whole system can motion mobile working. A novel control strategy of differential driving principle has been presented in order to solve the problem that electrode can't be revolved owing compact size has been resolved. Coaxial forced vibration of electrode is benefit for the evacuation of debris, and it helps to achieve stable and efficient machining. Analysis of harmonic response and the theoretical value of amplitude have been carried out. The optimal design of ultrasonic motor has been implemented using animate function of ANSYS and optimal design means, and the interference between teeth of stator has been avoided. Auto-frequency tracking has been completed, and electrode lateral vibration of electrode has been eliminated. Finally, the holes with figures of ?85?m circle, Y have been machined.

Tang, Yongjun; Guo, Zhongning; Zhang, Yongjun

2007-10-01

146

The Investigation of EDM Parameters on Electrode Wear Ratio  

Directory of Open Access Journals (Sweden)

Full Text Available Electrical Discharge Machining (EDM is a well-established machining option for manufacturing geometrically complex or hard material parts that are extremely difficult-to-machine by conventional machining processes. The non-contact machining technique has been continuously evolving from a mere tool and die making process. In this study, the influence of different electro discharge machining parameters (current, pulse on-time, pulse off-time, arc voltage on the electrode wear ratio as a result of application copper electrode to hot work steel DIN1.2344 has been investigated. Design of the experiment was chosen as full factorial. Artificial neural network has been used to choose proper machining parameters and to reach certain electrode wear ratio. Finally a hybrid model has been designed to reduce the artificial neural network errors. The experiment results indicated a good performance of proposed method in optimization of such a complex and non-linear problems.

Reza Atefi

2012-05-01

147

Geant4 Developments for the Radon Electric Dipole Moment Search at TRIUMF  

International Nuclear Information System (INIS)

An experiment is being developed at TRIUMF to search for a time-reversal violating electric dipole moment (EDM) in odd-A isotopes of Rn. Extensive simulations of the experiment are being performed with GEANT4 to study the backgrounds and sensitivity of the proposed measurement technique involving the detection of ? rays emitted following the ? decay of polarized Rn nuclei. GEANT4 developments for the RnEDM experiment include both realistic modelling of the detector geometry and full tracking of the radioactive ?, ?, internal conversion, and x-ray processes, including the ?-ray angular distributions essential for measuring an atomic EDM.

2011-09-23

148

New bounds on the electric dipole moment of the electron and on T-odd electron-nucleon coupling  

International Nuclear Information System (INIS)

The electric dipole moment (EDM) of the electron, together with the hyperfine coupling, induces an EDM in atoms and molecules with closed electron shells. Experiments with "1"2"9Xe and TIF have yielded bounds on the EDM of the electron (d/Vertical BareVertical Bar = (0.4 +- 1.4) x 10"-"2"3 cm; (0.9 +- 1.3) x 10"-"2"3 cm) and on the T-odd scalar electron-nucleon coupling constant

1985-11-01

149

A search for direct electron production in anti pp interactions at 70 GeV/c  

International Nuclear Information System (INIS)

A search for directly produced electrons in 70 GeV/c anti pp interactions has been performed using BEBC equipped with a hydrogen filled track sensitive target surrounded by a hydrogen/neon blanket. No candidates for single electron production with momentum psub(e) > 500 MeV/c were found in a sample of 66,000 primary interactions. This result places an upper limit of 2.5 ?b on the cross section for single esup(+-) production at the 90% confidence level. The corresponding upper limit on the charmed particle production cross section is 14 ?b. From the observation of 7 events producing an e+e- pair with mass msub(e)sub(+)sub(e)sub(-) > msub(?)0 the esup(+-)/?sup(+-) ratio from this source is estimated to be (0.7 +- 0.2) x 10-4. (orig.)

1981-01-01

150

Search for muon-electron and muon-positron conversion in sulfur  

Energy Technology Data Exchange (ETDEWEB)

An experiment to search for the neutrinoless conversion of a muon into an electron or a positron in the processes ..mu../sup -/ + /sup 32/S ..-->.. e/sup -/ + /sup 32/S and ..mu../sup -/ + /sup 32/S ..-->.. e/sup +/ + /sup 32/Sisup(*) has been carried out at SIN. No evidence for the occurrence of these conversion processes has been found. The resulting new upper limits (under certain assumption about coherence), relative to ordinary muon capture, are 7 X 10/sup -11/ (90% CL) for ..mu../sup -/ ..-->.. e/sup -/conversion and 9 X 10/sup -10/ (90% CL) for ..mu../sup -/ ..-->.. e/sup +/ conversion. The measured momentum spectra of the electrons and positrons are compatible with the background spectra expected from bound muon decay and radiative muon capture.

Badertscher, A.; Borer, K.; Czapek, G.; Flueckiger, A.; Haenni, H.; Hahn, B.; Hugentobler, E.; Markees, A.; Marti, T.; Moser, U. (Bern Univ. (Switzerland). Abt. fuer Hochenergiephysik)

1982-03-29

151

A search for muon-electron and muon-positron conversion in sulfur  

International Nuclear Information System (INIS)

An experiment to search for the neutrinoless conversion of a muon into an electron or a positron in the processes ?"- + "3"2S ? e"- + "3"2S and ?"- + "3"2S ? e"+ + "3"2Sisup(*) has been carried out at SIN. No evidence for the occurrence of these conversion processes has been found. The resulting new upper limits (under certain assumption about coherence), relative to ordinary muon capture, are 7 X 10"-"1"1 (90% CL) for ?"- ? e"-conversion and 9 X 10"-"1"0 (90% CL) for ?"- ? e"+ conversion. The measured momentum spectra of the electrons and positrons are compatible with the background spectra expected from bound muon decay and radiative muon capture. (orig.)

1982-03-29

152

Stochastic search, fragmentation, electronic and reactivity properties of neutral and cationic hydrogenated Li6 clusters  

Science.gov (United States)

In this study we investigated the lowest energy structures of neutral and cationic Li6Hn (n = 0–7) clusters using ab initio calculations based on DFT and CCSD(T) methods. We used the stochastic search method to obtain the global minimum on the potential energy surface of hydrogenated lithium clusters. For the lowest-energy isomers of the clusters, the relative stabilities, electronic and reactivity properties are presented depending on the binding energies, second energy difference, chemical hardness, chemical potential, softness, electrophilicity index, ionization potentials, electron affinities and HOMO–LUMO energy gaps. We also studied the fragmentation energies of neutral and cationic hydrogenated lithium clusters. In particular, the fragmentation energies of cationic clusters are compared with experimental data. The results are in good agreement with most available experimental findings.

Muz, ?skender; Ati?, Murat; Canko, Osman

2014-05-01

153

The prospects for an electron electric dipole moment search with ferroelectric (Eu,Ba)TiO$_3$ ceramics  

CERN Document Server

We propose to use ferroelectric (Eu,Ba)TiO$_3$ ceramics just above their magnetic ordering temperature for a sensitive electron electric dipole moment search. We have synthesized a number of such ceramics with various Eu concentrations and measured their properties relevant for such a search: permeability, magnetization noise, and ferroelectric hysteresis loops. The results of our measurements indicate that a search for the electron electric dipole moment with Eu$_{0.5}$Ba$_{0.5}$TiO$_3$ should lead to an order of magnitude improvement on the current best limit.

Sushkov, A O; Lamoreaux, S K

2009-01-01

154

Simulation of Fatigue Crack Initiation at Corrosion Pits With EDM Notches  

Science.gov (United States)

Uniaxial fatigue tests were conducted to compare the fatigue life of laboratory produced corrosion pits, similar to those observed in the shuttle main landing gear wheel bolt-hole, and an electro-discharged-machined (EDM) flaw. EDM Jaws are used to simulate corrosion pits during shuttle wheel (dynamometer) testing. The aluminum alloy, (AA 7050) laboratory fatigue tests were conducted to simulate the local stress level contained in the wheel bolt-hole. Under this high local stress condition, the EDM notch produced a fatigue life similar to test specimens containing corrosion pits of similar size. Based on the laboratory fatigue test results, the EDM Jaw (semi-circular disc shaped) produces a local stress state similar to corrosion pits and can be used to simulate a corrosion pit during the shuttle wheel dynamometer tests.

Smith, Stephen W.; Newman, John A.; Piascik, Robert S.

2003-01-01

155

Updating of EXPLOR and EDM models and the reference case study simulation  

Energy Technology Data Exchange (ETDEWEB)

The definition of the tasks in the contract relating to Explor and EDM is as follows: Projections of I/O coefficients for 1980, 1985 and 1990. Updating of exogeneous Explor data. Re-estimation of EDM equations using the latest historical data. The basis for the projections and updating of the exogeneous data for Explor is the database of the Cambridge Multisectoral Dynamic Model (MDM), of the UK economy.

Hughes, C.

1983-01-01

156

Modeling and Analysis of MRR, EWR and Surface Roughness in EDM Milling through Response Surface Methodology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Problem statement: Electrical Discharge Machining (EDM) has grown over the last few decades from a novelty to a mainstream manufacturing process. Though, EDM process is very demanding but the mechanism of the process is complex and far from completely understood. It is difficult to establish a model that can accurately predict the performance by correlating the process parameters. The optimum processing parameters are essential to increase the production rate and decrease the machining...

2010-01-01

157

Development of an Eco-Friendly Electrical Discharge Machine (E-EDM) Using TRIZ Approach  

Science.gov (United States)

Electrical Discharge Machine (EDM) is one of the non-traditional machining processes. EDM process is based on thermoelectric energy between the work and an electrode. A pulse discharge occurs in a small gap between the work piece and the electrode and removes the unwanted material from the parent metal through melting and vaporization. The electrode and the work piece must have an electrical conductivity in order to generate the spark. Dielectric fluid acts as a spark conductor, concentrating the energy to a very narrow region. There are various types of products can be produced and finished using EDM such as Moulds, Dies, Parts of Aerodynamics, Automotives and Surgical components. This research work reveals how an Eco friendly EDM (E-EDM) can be modeled to replace die electric fluid and introducing ozonised oxygen in to EDM to eliminate harmful effects generated while machining by using dielectric, to make pollution free machining environment through a new design of EEDM using TRIZ (a Russian acronym for Theory of Inventive Problem Solving) approach, since Eco friendly design is the need of the hour.

Sreebalaji, V. S.; Saravanan, R.

158

Variationally localized search direction method for constrained optimization of non-orthogonal, localized orbitals in electronic structure calculations  

Science.gov (United States)

A new method for the constrained optimization of non-orthogonal, spatially localized orbitals using direct energy minimization techniques, in the context of electronic structure calculations, is presented. The variationally localized search direction (VLSD) method, as it was named, ensures that strict localization constraints are imposed upon the search direction vectors exactly, analytically and in a fully variational fashion. In contrast, the truncated search direction (TSD) method, of standard use in many electronic structure approaches with localization constraints, relies on the approximation that the truncated search direction vectors of the unconstrained problem resemble the exact search direction vectors of the constrained problem. With the TSD method, in order to maintain the localization constraints, a part of the pre-calculated information that is stored in the search direction vectors has to be deleted via an ad hoc, non-variational truncation step. The results on an extensive set of test molecules show that, in general, calculations with the VLSD method require less iterations to converge than with the TSD method for any size of the localization region. It was found that in calculations on certain systems where the TSD method is forced to delete a very large amount of information, the VLSD method is capable of achieving convergence in up to three times less iterations. Validation tests show that structural and electronic properties calculated with either method are accurate and in agreement with other electronic structure approaches.

Ruiz-Serrano, Álvaro; Skylaris, Chris-Kriton

2013-10-01

159

Effects of Heat Treatments on the On-Line Service Life of a Press Die Manufactured by W-Edm  

Science.gov (United States)

Effects of heat treatments on the on-line service life of a press die manufactured by W-EDM are studied. In this work, four manufacturing processes for a press die are considered: (1) milling and then grinding, (2) wire-cut electric discharge machining (W-EDM), (3) low temperature heat treatment after W-EDM, and (4) high temperature heat treatment after W-EDM. On-line punching experiments for an automobile part of BL646-chain are performed. The amount of wear of the die and punch, roll-over and burnish depth in the punched chain are measured every 1,000 strokes. Overall productivities are carefully compared. Finally, it is concluded that heat treatment after W-EDM for a press die can enhance its on-line service life. Especially, high temperature heat treatment after W-EDM is very attractive as a fast and cheap manufacturing method for a press die.

Choi, Kye-Kwang; Lee, Yong-Shin

160

Searching for biosignatures using electron paramagnetic resonance (EPR) analysis of manganese oxides.  

Science.gov (United States)

Manganese oxide (Mn oxide) minerals from bacterial sources produce electron paramagnetic resonance (EPR) spectral signatures that are mostly distinct from those of synthetic simulants and abiogenic mineral Mn oxides. Biogenic Mn oxides exhibit only narrow EPR spectral linewidths (?500 G), whereas abiogenic Mn oxides produce spectral linewidths that are 2-6 times broader and range from 1200 to 3000 G. This distinction is consistent with X-ray structural observations that biogenic Mn oxides have abundant layer site vacancies and edge terminations and are mostly of single ionic species [i.e., Mn(IV)], all of which favor narrow EPR linewidths. In contrast, abiogenic Mn oxides have fewer lattice vacancies, larger particle sizes, and mixed ionic species [Mn(III) and Mn(IV)], which lead to the broader linewidths. These properties could be utilized in the search for extraterrestrial physicochemical biosignatures, for example, on Mars missions that include a miniature version of an EPR spectrometer. PMID:21970705

Kim, Soon Sam; Bargar, John R; Nealson, Kenneth H; Flood, Beverly E; Kirschvink, Joseph L; Raub, Timothy D; Tebo, Bradley M; Villalobos, Mario

2011-10-01

 
 
 
 
161

Search Hanford Accessible Reports Electronically system test plan and documentation: Revision 1  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this document is to describe the following items: the approach, resources, and sequence of the testing activities; identifies the components and features to be tested; the personnel responsible for testing; the risks associated with this plan; and test cases and procedures. This document contains all test documentation for the SHARE system. The Search Hanford Accessible Reports Electronically (SHARE) testing process is based upon WHC-CM-3-10, Software Practices, Section SP-3.3 REV 0, and Appendix J REV 0. These procedures and guidelines are based on IEEE Standard 829-1983. The planning in this document was further influenced through guidance in IEEE Standard 1012-1986. This document contains the System, Acceptance, Integration and Component Test Plans, Designs, Procedures, and Cases for SHARE. The Test Cases and procedures have been attached to the document.

White, E.L.

1994-12-07

162

Demonstration of surface electron rejection with interleaved germanium detectors for dark matter searches  

Energy Technology Data Exchange (ETDEWEB)

The SuperCDMS experiment in the Soudan Underground Laboratory searches for dark matter with a 9-kg array of cryogenic germanium detectors. Symmetric sensors on opposite sides measure both charge and phonons from each particle interaction, providing excellent discrimination between electron and nuclear recoils, and between surface and interior events. Surface event rejection capabilities were tested with two {sup 210}Pb sources producing ?130 beta decays/hr. In ?800 live hours, no events leaked into the 8–115 keV signal region, giving upper limit leakage fraction 1.7 × 10{sup ?5} at 90% C.L., corresponding to < 0.6 surface event background in the future 200-kg SuperCDMS SNOLAB experiment.

Agnese, R.; Balakishiyeva, D.; Saab, T.; Welliver, B. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Anderson, A. J.; Figueroa-Feliciano, E.; Hertel, S. A.; McCarthy, K. A. [Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Basu Thakur, R. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illnois 61801 (United States); Bauer, D. A.; Holmgren, D.; Hsu, L.; Loer, B.; Schmitt, R. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Borgland, A.; Brandt, D.; Brink, P. L.; Do Couto E Silva, E.; Godfrey, G. L.; Hasi, J. [SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Collaboration: The SuperCDMS Collaboration; and others

2013-10-14

163

New Results from MiniBooNE: A Search for Electron Antineutrino Appearance at $\\sim$1 eV$^2$  

Energy Technology Data Exchange (ETDEWEB)

These proceedings summarize the first MiniBooNE electron antineutrino appearance search results, corresponding to a data sample collected for 3.39 x 10{sup 20} protons on target (POT). The search serves as a direct test of the LSND oscillation signature, and provides complementary information which can be used in studies addressing the MiniBooNE neutrino-mode low-energy excess.

Karagiorgi, Georgia S.; Collaboration, for the MiniBooNE

2009-10-01

164

Calculation of Neutron EDM in quenched and full QCD  

CERN Document Server

We report on a direct lattice calculation of the neutron EDM(NEDM) using the external electric field method in both quenched and full QCD. In quenched QCD, we use a $24^3\\times 32$ lattice at $\\beta=2.6$ with the Iwasaki gauge action and the clover fermion action to examine the viability of this method. In particular we investigate possible effects of violation of the periodic boundary condition of the external electric field on the NEDM signal. We also study the quark mass dependence of NEDM in quenched QCD, and observe that NEDM seems to remain non-zero toward the chiral limit because of the quenched artifact. In 2-flavor full QCD we employ configurations generated by the CP-PACS collaboration on a $24^3\\times 48$ lattice at $\\beta=2.1$ with the same gluon and quark actions as in the quenched case. Since the number of configurations is limited, we employ 8 different source points per one configuration and take an average over them. Our preliminary result at three quark masses ($m_{PS}/m_V\\simeq 0.81, 0.76, ...

Shintani, E; Ishizuka, N; Kanaya, K; Kuramashi, Y; Okawa, M; Ukawa, A; Yoshié, T

2006-01-01

165

On machine measurements of electrode wear in micro EDM milling  

DEFF Research Database (Denmark)

The electrode wear in micro electrical discharge milling (micro EDM milling) is one of the main problems to be solved in order to improve machining accuracy. Most common, the electrode wear is measured on machine by touching the reference point with the tip of the electrode (Touch method) after machining a certain number of layers. The reduction of the electrode length due to the wear (linear wear) is used to modify the electrode trajectory. A laser scan micrometer (LSM) is implemented on the machine mostly to acquire electrode profiles after dressing of the electrode is applied. It is also an alternative solution to measure the linear and volumetric wear, which in principle should be more accurate compared to the measurements performed by The Touch method. In this paper, the performance of the two systems, namely Touch and LSM, were compared. The experimental results show that the accuracy of the electrode length measurement by the Touch method is enough accurate for the linear wear estimation, but the volumetric wear should be measured by LSM system.

Valentincic, J.; Bissacco, Giuliano

2003-01-01

166

Search for an admixture of sterile neutrino in the electron spectrum from tritium $\\beta$-decay  

CERN Document Server

We propose an experiment intended for search for an admixture of sterile neutrino with mass m$_s$ in the range of 1-8 keV that may be detected as specific distortion of the electron energy spectrum during tritium decay. The distortion is spread over large part of the spectrum so to reveal it one can use a detector with relatively poor (near 10-15%) energy resolution. A classic proportional counter is a simple natural choice for a tritium $\\beta$-decay detector. The method we are proposing is original in two respects. First, the counter is produced as a whole from fully-fused quartz tube allowing to measure current pulse directly from anode while providing high stability for a long time. Second, a modern digital acquisition technique can be used in measurements at ultrahigh count rate - up to 10$^6$ Hz. As a result an energy spectrum of tritium electrons containing up to 10$^{12}$ counts may be collected in a month of live time measurements. Due to high statistics an upper limit down to 10$^{-3}$..10$^{-5}$ ca...

Abdurashitov, D; Likhovid, N; Lokhov, A; Tkachev, I; Yants, V

2014-01-01

167

Search for the density effect in inner-shell ionization by ultra relativistic electron impact  

International Nuclear Information System (INIS)

We have extended the measurements of K- and L-shell ionization cross sections by electron impact into the ultra relativistic energy region, 0.9 <= E <= 2.0 GeV, in order to search for a saturation of the cross section. The phenomenon, which is due to the target medium, is called density effect. It is predicted to occur at several hundred MeV impact energy and preferentially for low Z target elements. Theoretical calculations are presented, based on the one-photon exchange approximation. The absolute measurements of the K- and L-shell cross sections for Ni(K), Cu(K), Ag(K,L) and Au(L) performed at the 2.5 GeV electron synchrotron of the University Bonn, however, exhibit that the cross sections show no saturation but are still increasing. Furthermore, from the KX-ray yields, obtained at 0.9 and 2.0 GeV by bombarding the low Z elements S, Ca, Mn, Ni and Ge, we obtain for the corresponding cross section ratio sigmasub(K)(2 GeV)/sigmasub(K)(0.9 GeV) = 1.08 +- 0.012 on the average. (orig./WL)

1982-01-01

168

Search for a New Gauge Boson in Electron-Nucleus Fixed-Target Scattering by the APEX Experiment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling ?? to electrons. Such a particle A? can be produced in electron-nucleus fixed-target scattering and then decay to an e[superscript +]e[superscript -] pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175–250 MeV, found no evidence for an A??e[superscript +]e[superscript -] reaction, and set an upper...

2011-01-01

169

Secondary scintillation yield from GEM and THGEM gaseous electron multipliers for direct dark matter search  

Science.gov (United States)

The search for alternatives to PMTs as photosensors in optical TPCs for rare event detection has significantly increased in the last few years. In particular, in view of the next generation large volume detectors, the use of photosensors with lower natural radioactivity, such as large area APDs or GM-APDs, with the additional possibility of sparse surface coverage, triggered the intense study of secondary scintillation production in micropattern electron multipliers, such as GEMs and THGEMs, as alternatives to the commonly used uniform electric field region between two parallel meshes. The much higher scintillation output obtained from the electron avalanches in such microstructures presents an advantage in those situations. The accurate knowledge of the amount of such scintillation is important for correct detector simulation and optimization. It will also serve as a benchmark for software tools developed and/or under development for the calculation of the amount of such scintillation.The secondary scintillation yield, or electroluminescence yield, in the electron avalanches of GEMs and THGEMs operating in gaseous xenon and argon has been determined for different gas pressures. At 1 bar, THGEMs deliver electroluminescence yields that are more than one order of magnitude higher when compared to those achieved in GEMs and two orders of magnitude when compared to those achieved in a uniform field gap. The THGEM electroluminescence yield presents a faster decrease with pressure when comparing to the GEM electroluminescence yield, reaching similar values to what is achieved in GEMs for xenon pressures of 2.5 bar, but still one order of magnitude higher than that produced in a uniform field gap. Another exception is the GEM operating in argon, which presents an electroluminescence yield similar to that produced in a uniform electric field gap, while the THGEM achieves yields that are more than one order of magnitude higher.

Monteiro, C. M. B.; Fernandes, L. M. P.; Veloso, J. F. C. A.; Oliveira, C. A. B.; dos Santos, J. M. F.

2012-07-01

170

Secondary scintillation yield from GEM and THGEM gaseous electron multipliers for direct dark matter search  

International Nuclear Information System (INIS)

The search for alternatives to PMTs as photosensors in optical TPCs for rare event detection has significantly increased in the last few years. In particular, in view of the next generation large volume detectors, the use of photosensors with lower natural radioactivity, such as large area APDs or GM-APDs, with the additional possibility of sparse surface coverage, triggered the intense study of secondary scintillation production in micropattern electron multipliers, such as GEMs and THGEMs, as alternatives to the commonly used uniform electric field region between two parallel meshes. The much higher scintillation output obtained from the electron avalanches in such microstructures presents an advantage in those situations. The accurate knowledge of the amount of such scintillation is important for correct detector simulation and optimization. It will also serve as a benchmark for software tools developed and/or under development for the calculation of the amount of such scintillation. The secondary scintillation yield, or electroluminescence yield, in the electron avalanches of GEMs and THGEMs operating in gaseous xenon and argon has been determined for different gas pressures. At 1 bar, THGEMs deliver electroluminescence yields that are more than one order of magnitude higher when compared to those achieved in GEMs and two orders of magnitude when compared to those achieved in a uniform field gap. The THGEM electroluminescence yield presents a faster decrease with pressure when comparing to the GEM electroluminescence yield, reaching similar values to what is achieved in GEMs for xenon pressures of 2.5 bar, but still one order of magnitude higher than that produced in a uniform field gap. Another exception is the GEM operating in argon, which presents an electroluminescence yield similar to that produced in a uniform electric field gap, while the THGEM achieves yields that are more than one order of magnitude higher.

2012-07-24

171

Optimization of EDM Process Parameters on Titanium Super Alloys Based on the Grey Relational Analysis  

Directory of Open Access Journals (Sweden)

Full Text Available Electrical discharge machining (EDM is a unconventional machining process for the machining of complex shapes and hard materials that are difficult of machining by conventional machining process. In this paper deals with the optimization of EDM process parameters using the grey relational analysis (GRA based on an orthogonal array for the multi response process. The experiments are conducted on Titanium super alloys with copper electrode based on the Taguchi design of experiments L27 orthogonal array by choosing various parameters such as peak current, pulse on time, pulse off time and tool lift time for EDM process to obtain multiple process responses namely Metal removal rate (MRR and Tool Wear Rate (TWR. The combination of Taguchi method with GRA enables to determine the optimal parameters for multiple response process. Gray relational analysis is used to obtain a performance index called gray relational grade to optimize the EDM process with higher MRR and lower TWR and it is clearly found that the performance of the EDM has greatly increased by optimizing the responses the influence of individual machining parameters also investigated by using analysis of variance for the grey relational grade.

J. Laxman, Dr. K. Guru Raj

2014-05-01

172

XENON100 Dark Matter Search: Scintillation Response of Liquid Xenon to Electronic Recoils  

Science.gov (United States)

Dark matter is one of the missing pieces necessary to complete the puzzle of the universe. Numerous astrophysical observations at all scales suggest that 23 % of the universe is made of nonluminous, cold, collisionless, nonbaryonic, yet undiscovered dark matter. Weakly Interacting Massive Particles (WIMPs) are the most well-motivated dark matter candidates and significant efforts have been made to search for WIMPs. The XENON100 dark matter experiment is currently the most sensitive experiment in the global race for the first direct detection of WIMP dark matter. XENON100 is a dual-phase (liquid-gas) time projection chamber containing a total of 161 kg of liquid xenon (LXe) with a 62kg WIMP target mass. It has been built with radiopure materials to achieve an ultra-low electromagnetic background and operated at the Laboratori Nazionali del Gran Sasso in Italy. WIMPs are expected to scatter off xenon nuclei in the target volume. Simultaneous measurement of ionization and scintillation produced by nuclear recoils allows for the detection of WIMPs in XENON100. Data from the XENON100 experiment have resulted in the most stringent limits on the spin-independent elastic WIMP-nucleon scattering cross sections for most of the significant WIMP masses. As the experimental precision increases, a better understanding of the scintillation and ionization response of LXe to low energy (well as to interpret dark matter results such as annual modulation, measurement of the scintillation yield of low-energy electrons in LXe was performed in 2011, with the dedicated setup mentioned above. The results from this measurement are discussed in Chap. 6. Finally, the results for the latest science data from XENON100 to search for WIMPs, comprising 225 live-days taken over 13 months during 2011 and 2012 are explained in Chap. 7.

Lim, Kyungeun Elizabeth

173

Searching for electronic journal articles to support academic tasks. A case study of the use of the Finnish National Electronic Library (FinELib  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction. We analyse how academic status and discipline influence the major search methods used by university academic staff for obtaining electronic articles for teaching, research and keeping up to date in their field. Method. The data consist of a nationwide Web-survey of the end-users of FinELib, The Finnish National Electronic Library. The number of respondents was 900. Analysis. Cross tabulations and multivariate analyses were used for answering research questions. Results. Keyword searching in journal and reference databases were clearly the most important access methods in all disciplines compared to browsing, chaining or obtaining material from colleagues. Academic status and discipline influenced the patterning of search methods used. Keyword searching in databases was more common in natural sciences, engineering and medicine than in other disciplines. Semi-directed searching comprised of browsing, chaining and colleagues as sources of access. It was significantly more common in humanities than in other disciplines. Conclusion. Patterns of searching for journal articles are changing because of the provision of digital information resources. In particular, the role of colleagues is diminishing.

Pertti Vakkari

2006-01-01

174

Search for a new gauge boson in electron-nucleus fixed-target scattering by the APEX experiment.  

Science.gov (United States)

We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling ?' to electrons. Such a particle A' can be produced in electron-nucleus fixed-target scattering and then decay to an e + e- pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175-250 MeV, found no evidence for an A'? e+ e- reaction, and set an upper limit of ?'/? ~/= 10(-6). Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces. PMID:22181599

Abrahamyan, S; Ahmed, Z; Allada, K; Anez, D; Averett, T; Barbieri, A; Bartlett, K; Beacham, J; Bono, J; Boyce, J R; Brindza, P; Camsonne, A; Cranmer, K; Dalton, M M; de Jager, C W; Donaghy, J; Essig, R; Field, C; Folts, E; Gasparian, A; Goeckner-Wald, N; Gomez, J; Graham, M; Hansen, J-O; Higinbotham, D W; Holmstrom, T; Huang, J; Iqbal, S; Jaros, J; Jensen, E; Kelleher, A; Khandaker, M; LeRose, J J; Lindgren, R; Liyanage, N; Long, E; Mammei, J; Markowitz, P; Maruyama, T; Maxwell, V; Mayilyan, S; McDonald, J; Michaels, R; Moffeit, K; Nelyubin, V; Odian, A; Oriunno, M; Partridge, R; Paolone, M; Piasetzky, E; Pomerantz, I; Qiang, Y; Riordan, S; Roblin, Y; Sawatzky, B; Schuster, P; Segal, J; Selvy, L; Shahinyan, A; Subedi, R; Sulkosky, V; Stepanyan, S; Toro, N; Walz, D; Wojtsekhowski, B; Zhang, J

2011-11-01

175

Prospects for an electron electric-dipole-moment search with ferroelectric (Eu,Ba)TiO3 ceramics  

International Nuclear Information System (INIS)

We propose to use ferroelectric (Eu,Ba)TiO3 ceramics just above their magnetic ordering temperature for a sensitive electron electric-dipole-moment search. We have synthesized a number of such ceramics with various europium concentrations and measured their properties relevant for such a search: permeability, magnetization noise, and ferroelectric hysteresis loops. We also identify and estimate the likely systematics: the magnetoelectric effect, hysteresis-loop heating, and ferroelectric relaxation currents. Our measurements and estimates indicate that a search for the electron electric dipole moment with Eu0.5Ba0.5TiO3 could lead to an order of magnitude improvement on the current best limit, if the systematic effects can be controlled.

2010-02-01

176

The nEDM experiment at the Paul Scherrer Institute, Switzerland  

Science.gov (United States)

A permanent electric dipole moment of the neutron would be a sign of combined charge-conjugation and parity (CP) violation. The prediction of the Standard Model (SM) of particle physics for the neutron EDM is about 10-31 e cm and at the same time CP violation in the SM is insufficient in order to explain the observed baryon asymmetry of the universe (BAU). Several extensions of the SM aiming at explaining the observed BAU also predict values for the neutron EDM up to just below the current best experimental limit of dn <2.9×10-26e cm (90%C.L.) [1]. Our collaboration aims at improving the experimental sensitivity to the nEDM by two orders of magnitude which will probe a large part of the parameter space for these models.

Zenner, Johannes; nEDM Collaboration

2013-10-01

177

A new electrode wear compensation method for improving performance in 3D micro EDM milling  

Science.gov (United States)

As one of the non-traditional manufacturing processes, micro electrical discharge machining (EDM) has been widely applied for manufacturing precise and complex microstructures. However, a number of issues remain to be studied before micro EDM can become a reliable processing method. Efforts to get higher machining quality and to improve efficiency have been carried out. The electrode wear compensation method is one of the key factors in micro EDM milling. This paper proposes a new electrode wear compensation method, the combination of the linear compensation method (LCM) and the uniform wear method (UWM), called the CLU method. This approach combines LCM, UWM and the theoretical model. Experimental results indicate that machining performance such as material removal rate, electrode wear ratio and surface roughness using the proposed method has been improved compared to that by the uniform wear method.

Yu, Hui-Lan; Luan, Ji-Jie; Li, Jian-Zhong; Zhang, Yu-Sheng; Yu, Zu-Yuan; Guo, Dong-Ming

2010-05-01

178

EDM processing of tungsten monocrystal with given diameter and profile of holes and cavities along the depth  

International Nuclear Information System (INIS)

In this paper, a new method of material processing is treated, which is the broaching of deep holes with a variety of diameters and shapes uniformly by electrical discharges machining (EDM). The experimental results of surface structure after EDM is shown. (author)

1999-01-01

179

Practical evaluation of optical-proximity effect correction by EDM methodology  

Science.gov (United States)

Practical evaluation method for optical proximity effect correction (OPC) feasibility is newly proposed using EDM (Exposure-Defocus and Mask fabrication latitude) methodology. In this method, printed image on a wafer is characterized by process latitude functions derived from EDM methodology in terms of exposure latitude, depth of focus, and mask line width latitude. In this paper, effectiveness of the process latitude functions will be verified by applying them to intraproximity effect evaluation for isolated lines and angled lines, and also to interproximity effect evaluation for T-shaped patterns and lines & spaces (L/S) patterns in i-line lithography.

Sugawara, Minoru; Kawahira, Hiroichi; Tsudaka, Keisuke; Nozawa, Satoru

1995-05-01

180

The use of energy-data management systems (EDM) in the gas supply industry; Einsatz von Energiedaten-Managementsystemen (EDM) in der Gasversorgung  

Energy Technology Data Exchange (ETDEWEB)

The new background legal conditions created by the Energiewirtschaftsgesetz (Energy Management Act) and the Verbaendevereinbarung Gas (Inter-Association Agreement for Gas) produce radical changes in the requirements made on dataprocessing systems used by the supply utilities and by new entrants to the market. This article presents new ideas and conceptual solutions, such as the Energy Data Management (EDM) system and provides orientational notes and information for implementation of the new requirements for both existing traders and new entrants to the market. (orig.) [German] Die neuen gesetzlichen Rahmenbedingungen durch das Energiewirtschaftsgesetz (EnWG) und die Verbaendevereinbarung Gas bewirken durchgreifende Veraenderungen der Anforderungen an die DV-Systeme in den Versorgungsunternehmen und bei den neuen Marktteilnehmern. Dieser Anteil zeigt neue Konzeptionen und Loesungsansaetze, wie z.B. das Energiedaten-Managementsystem (EDM) auf und gibt orientierende Hinweise und Informationen fuer die Umsetzung der neuen Anforderungen fuer die bisherigen und neuen Marktteilnehmer. (orig.)

Groepl, A. [Systema Unternehmensberatung fuer Informationstechnik GmbH, Mannheim (Germany)

2000-09-01

 
 
 
 
181

Search for Long-Lived Particles Decaying into Electron or Photon Pairs with the D0 Detector  

International Nuclear Information System (INIS)

In this Letter we report on a search for long-lived particles that decay into final states with two electrons or photons. Such long-lived particles arise in a variety of theoretical models, such as hidden valleys and supersymmetry with gauge-mediated breaking. By precisely reconstructing the direction of the electromagnetic shower we are able to probe much longer lifetimes than previously explored. We see no evidence of the existence of such long-lived particles and interpret this search as a quasi model-independent limit on their production cross section, as well as a limit on a long-lived fourth generation quark

2008-09-12

182

Search for long-lived particles decaying into electron or photon pairs with the D0 detector  

CERN Document Server

In this Letter we report on a search for long-lived particles that decay into final states with two electrons or photons. Such long-lived particles arise in a variety of theoretical models, like hidden valleys and supersymmetry with gauge-mediated breaking. By precisely reconstructing the direction of the electromagnetic shower we are able to probe much longer lifetimes than previously explored. We see no evidence of the existence of such long-lived particles and interpret this search as a quasi model-independent limit on their production cross section, as well as a limit on a long-lived fourth generation quark.

Abazov, V M; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguiló, E; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Aoki, M; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; sman, B; Assis-Jesus, A C S; Atramentov, O; Avila, C; Badaud, F; Bagby, AL; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Barfuss, A F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benítez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Böhnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Bu, X B; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K; Chan, K M; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M C; Crepe-Renaudin, S; Cuplov, V; Cutts, D; Cwiok, M; Da Motta, H; Das, A; Davies, G; De, K; De Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Dliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; García, C; García-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gel, D; Gerber, C E; Gershtein, Yu; Gillberg, D; Ginther, G; Gollub, N; Gmez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, P; Grivaz, J F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutíerrez, G; Gutíerrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Kalk, J M; Karmanov, D; Kasper, P A; Katsanos, I; Kau, D; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Yu M; Khatidze, D; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J P; Kozelov, A V; Kraus, J; Kühl, T; Kumar, A; Kupco, A; Kura, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, W M; Leflat, A; Lellouch, J; Li, J; Li, L; Li, Q Z; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajícek, M; Love, P; Lubatti, H J; Luna, R; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Millet, T; Mitrevski, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osman, N; Osta, J; Otec, R; Oteroy-Garzon, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E; Polozov, P; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rich, P; Rieger, J; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Savage, G; Sawyer, L

2008-01-01

183

Relationship of Surface Roughness with Current and Voltage During Wire EDM  

Directory of Open Access Journals (Sweden)

Full Text Available Wire EDM is in use for a long time for cutting punches and dies, shaped pockets and other machine parts. Surface finish of the machined surface mainly depends on current and voltage used during machining. In the present research experimental investigations have been conducted to establish relationships of job surface finish with current and voltage. Brass wires of diameters 0.3, 0.25, 0.20 and 0.15 mm were used. Work materials tested were mild steel, aluminum, cemented carbide, copper and stainless steel. After machining each material with specific current and voltage the hardness and the job surface roughness were measured and their surfaces were observed under an electron-scanning microscope. Results of the experiments show that in general the machined surface becomes rougher with increase in current and voltage. Microstructures of the specimens also show that craters on the finished surface become larger as a result of using higher current and voltage. It was also found that wires of smaller diameters give smoother surface than those cut with larger diameters. It has been established that machining of carbides should be limited to wires with diameter equal to or less than 0.15 mm. Use of wires of greater diameters causes frequent wire breakage. A statistical analysis was done to pick up the most probabilistic data from the bank of data obtained from the experiments. Finally, mathematical relationships have been developed between job surface finish with current and voltage within the specified ranges for a few work materials.

Ahsan Ali Khan

2006-01-01

184

Avaliação da geração de microtrincas do aço rápido ABNT M2 no processo EDM com adição de SiC = Evaluation of microcrack formation of ABNT M2 high speed steel in the EDM process, with addition of silicon carbide powder  

Directory of Open Access Journals (Sweden)

Full Text Available É sabido que a Usinagem por Descargas Elétricas (EDM é um processo térmico em que pode haver temperaturas muito elevadas (superiores a 1.200°C na região de usinagem. Consequentemente é fácil de entender o fato de as peças usinadas por EDM apresentarem camadas superficiais endurecidas, refundidas e com elevado número de microtrincas superficiais. A formação de microtrincas está associada com o desenvolvimento de altas tensões térmicas que excedem a tensão máxima de resistência do material. Além disso, as microtrincas superficiais penetram em profundidade com extensões que dependem da energia de descarga. O trabalho proposto tem por objetivo estudar o efeito da adição de pó de SiC em vários fluidos dielétricos, sobre a geração de microtrincas superficiais, no aço rápido ABNT M2, durante a usinagem por descargas elétricas. Os resultados apresentados mostramredução da quantidade de microtrincas nas superfícies usinadas, quando se adiciona pó de SiC ao dielétrico, quando comparadas com as usinadas com EDM convencional.It is known that Electrical Discharge Machining (EDM is a thermal process in which extremely high temperatures (in excess of 1200°C can occur in the machining area. Consequently, it is easy tounderstand that during each electric discharge, high temperatures are generated, causing local fusion or even evaporation of the machined material. In each discharge, a crater is formed in the material and a small crater is formed in the electrode. Of every meltedmaterial produced in each discharge, only 15% or less is removed using dielectric fluid. The remaining melted material solidifies, forming a wrinkled surface. The characteristics of theobtained surface – overlap of craters, globules of sullage, chimneys, bubbles (formed when the gases arrested are liberated through the resolidified material – are revealed through an analysis using a scanning electron microscope. The proposed work has as its objective to study the effect of the addition of SiC powder into several dielectric fluids, on microcrack formation of high-speed steel (ABNT M2, during electrical discharge machining. The results show that the samples machined with the addition of SiC powders presentedsignificant reduction in the number of microcracks in the machined surface, when compared with those machined with conventional EDM.

Jean Robert Pereira Rodrigues

2008-07-01

185

Traveling wire electrode increases productivity of Electrical Discharge Machining /EDM/ equipment  

Science.gov (United States)

Traveling wire electrode on electrical discharge machining /EDM/ equipment reduces the time requirements for precision cutting. This device enables cutting with a minimum of lost material and without inducing stress beyond that inherent in the material. The use of wire increases accuracy and enables tighter tolerances to be maintained.

Kotora, J., Jr.; Smith, S. V.

1967-01-01

186

Analysis of aerosol emission and hazard evaluation of electrical discharge machining (EDM) process.  

Science.gov (United States)

The safety and environmental aspects of a manufacturing process are important due to increased environmental regulations and life quality. In this paper, the concentration of aerosols in the breathing zone of the operator of Electrical Discharge Machining (EDM), a commonly used non traditional manufacturing process is presented. The pattern of aerosol emissions from this process with varying process parameters such as peak current, pulse duration, dielectric flushing pressure and the level of dielectric was evaluated. Further, the HAZOP technique was employed to identify the inherent safety aspects and fire risk of the EDM process under different working conditions. The analysis of aerosol exposure showed that the concentration of aerosol was increased with increase in the peak current, pulse duration and dielectric level and was decreased with increase in the flushing pressure. It was also found that at higher values of peak current (7A) and pulse duration (520 micros), the concentration of aerosols at breathing zone of the operator was above the permissible exposure limit value for respirable particulates (5 mg/m(3)). HAZOP study of the EDM process showed that this process is vulnerable to fire and explosion hazards. A detailed discussion on preventing the fire and explosion hazard is presented in this paper. The emission and risk of fire of the EDM process can be minimized by selecting proper process parameters and employing appropriate control strategy. PMID:20720340

Jose, Mathew; Sivapirakasam, S P; Surianarayanan, M

2010-01-01

187

Surface Integrity of Inconel 718 by Wire-EDM at Different Energy Modes  

Science.gov (United States)

Inconel alloys including IN 718 alloy are widely used in turbomachinery industry due to their superior mechanical properties. Inconel alloys are very difficult to machine using cutting and grinding. Wire electrical discharge machining (W-EDM) is an alternative process to manufacture complex Inconel parts. However, little research has been done on surface integrity by W-EDMed IN 718. This study focuses on surface integrity of IN 718 by W-EDM at different modes of discharge energy. The results show that the EDMed surface topography shows dominant coral reef microstructures at high energy mode, while random microvoids are dominant at low energy modes. The average roughness can be significantly reduced at low energy mode. A thick white layer is predominantly discontinuous and non-uniform at relative high energy modes. Microvoids are confined within the thick white layers and no microcracks were found in the subsurface. A thin white layer by trim cut at low energy mode becomes continuous, uniform, and is free of voids. Compared to the bulk, white layers have dramatic reduction in microhardness. In addition, surface alloying from wire electrode and water dielectric is obvious in main cut, but it can be minimized in trim cuts.

Li, L.; Wei, X. T.; Guo, Y. B.; Li, W.; Liu, J. F.

2014-05-01

188

Study of surface integrity using the small area EDM process with a copper-tungsten electrode  

Energy Technology Data Exchange (ETDEWEB)

The present study performs the small area electro-discharge machining (EDM) process with a low wear-rate copper-tungsten electrode of diameter 1.5 mm to establish the influence of the EDM parameters on various aspects of the surface integrity of AISI 1045 carbon steel. The residual stress induced by the EDM process is measured using the Hole-Drilling Strain-Gage Method. The experimental results reveal that the values of material removal rate (MRR), surface roughness (SR), hole enlargement (HE), average white layer thickness (WLT), and induced residual stress tend to increase at higher values of pulse current and pulse-on duration. However, for an extended pulse-on duration, it is noted that the MRR, SR, and surface crack density all decrease. Furthermore, the results indicate that obvious cracks are always evident in thicker white layers. A smaller pulse current (i.e. 1 A) tends to increase the surface crack density, while a prolonged pulse-on duration (i.e. 23 {mu}s) widens the opening degree of the surface crack, thereby reducing the surface crack density. The EDM hole drilling process induces a compressive residual stress within the workpiece. A linear relationship is identified between the maximum residual stress and the average white layer thickness. It is determined that the residual stress can be controlled effectively by specifying an appropriate pulse-on duration.

Lee, H.-T.; Hsu, F.-C.; Tai, T.-Y

2004-01-15

189

Study of surface integrity using the small area EDM process with a copper-tungsten electrode  

International Nuclear Information System (INIS)

The present study performs the small area electro-discharge machining (EDM) process with a low wear-rate copper-tungsten electrode of diameter 1.5 mm to establish the influence of the EDM parameters on various aspects of the surface integrity of AISI 1045 carbon steel. The residual stress induced by the EDM process is measured using the Hole-Drilling Strain-Gage Method. The experimental results reveal that the values of material removal rate (MRR), surface roughness (SR), hole enlargement (HE), average white layer thickness (WLT), and induced residual stress tend to increase at higher values of pulse current and pulse-on duration. However, for an extended pulse-on duration, it is noted that the MRR, SR, and surface crack density all decrease. Furthermore, the results indicate that obvious cracks are always evident in thicker white layers. A smaller pulse current (i.e. 1 A) tends to increase the surface crack density, while a prolonged pulse-on duration (i.e. 23 ?s) widens the opening degree of the surface crack, thereby reducing the surface crack density. The EDM hole drilling process induces a compressive residual stress within the workpiece. A linear relationship is identified between the maximum residual stress and the average white layer thickness. It is determined that the residual stress can be controlled effectively by specifying an appropriate pulse-on duration

2004-01-15

190

Laser-pumped cesium magnetometers for the PSI-nEDM experiment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Die vorliegende Arbeit beschreibt die Entwicklung eines Magnetfeldsensors mit hoher Auflösung für ein Grundlagenforschungsprojekt im Rahmen einer internationalen Kollaboration unter Beteilung der Freiburger Atomphysikgruppe. Das Ziel des Projekts ist die Durchführung eines Experiments am Paul Scherrer Institut (PSI) zur Bestimmung des elektrischen Dipolmoments des Neutrons (nEDM: neutron electric dipole moment), d. Die mögliche Existenz und vor allem die Grösse eines solchen Dipolmoments...

Gro?ger, Stephan; Weis, Antoine; Dousse, Jean-claude; Daum, Manfred

2006-01-01

191

Surface defects in PMD-EDM of titanium alloy, Ti-6246  

International Nuclear Information System (INIS)

Titanium alloys which are categorized as lightweight materials, poses greater strength and toughness are usually known to create major challenges during machining. Electrical discharge machining (EDM) which is very prominent amongst the non-conventional machining methods is expected to be used quite extensively in machining titanium alloys. EDM process is known to cause surface damaged layers which consists of three types of surfaces; spattered, recast and heat affected zone. This project was undertaken to study the machining performance of EDM and powder mixed dielectric-electrical discharge machining (PMDEDM) in machining Ti-6246 with respect to the surface integrity of machined surface by using copper tungsten (CuW) electrode. The machining parameters considered are voltage (V), current (I), pulse on time(Ton), interval time (Toff) and concentration of the SiC powder (C) in dielectric fluid. The respected responses investigated include surface alteration and overcut. It was found that PMD-EDM process produced less damaging effect on the surface layer of the machined surface and widened the overcut. (author)

2007-11-26

192

OPTIMIZATION OF OPERATING PARAMETERS FOR EDM PROCESS BASED ON THE TAGUCHI METHOD AND ARTIFICIAL NEURAL NETWORK  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper the complexity of electrical discharge machining process which is very difficult to determine optimal cutting parameters for improving cutting performance has been reported. Optimization of operating parameters is an important step in machining, particularly for operating unconventional machiningprocedure like EDM. A suitable selection of machining parameters for the electrical discharge machining process relies heavily on the operators’ technologies and experience because of their numerous and diverse range. Machining parameters tables provided by the machine tool builder can not meet the operators’ requirements, since for anarbitrary desired machining time for a particular job, they do not provide the optimal machining conditions. An approach to determine parameters setting is proposed. Based on the Taguchi parameter design method and the analysis of variance, the significant factors affecting the machining performance such as total machining time, oversize and taper for a hole machined by EDM process, are determined.Artificial neural networks are highly flexible modeling tools with an ability to learn the mapping between input variables and output feature spaces. The superiority of using artificial neural networks inmodeling machining processes make easier to model the EDM process with dimensional input and output spaces. On the basis of the developed neural network model, for a required total machining time, oversize and taper the corresponding process parameters to be set in EDM by using the developed and trained ANN are determined.

A.Thillaivanan,

2010-12-01

193

Optimization Of Edm Parameters Using Taguchi Method And Grey Relational Analysis For Mild Steel Is 2026  

Directory of Open Access Journals (Sweden)

Full Text Available Optimization is one of the techniques used in manufacturing sectors to arrive for the best manufacturing conditions, which is an essential need for industries towards manufacturing of quality products at lower cost. This paper aims to investigate the optimal set of process parameters such as current, pulse ON and OFF time in Electrical Discharge Machining (EDM process to identify the variations in three performance characteristics such as rate of material removal, wear rate on tool, and surface roughness value on the work material for machining Mild Steel IS 2026 using copper electrode. Based on the experiments conducted on L9 orthogonal array, analysis has been carried out using Grey Relational Analysis, a Taguchi method. Response tables and graphs were used to find the optimal levels of parameters in EDM process. The confirmation experiments were carried out to validate the optimal results. Thus, the machining parameters for EDM were optimized for achieving the combined objectives of higher rate of material removal, lower wear rate on tool, and lower surface roughness value on the work material considered in this work. The obtained results show that the Taguchi Grey relational Analysis is being effective technique to optimize the machining parameters for EDM process.

RAGHURAMAN S, THIRUPPATHI K, PANNEERSELVAM T, SANTOSH S

2013-07-01

194

Search for Associated Chargino-Neutralino Production in Final States with Two Electrons and an additional Lepton  

Science.gov (United States)

We present a search for chargino-neutralino production based on approximately 300 pb-1 of Tevatron Run II data collected in proton anti-proton collisions at ?s = 1.96 TeV with the Collider Detector at Fermilab (CDF). We perform a blind analysis and we check our predictions of the Standard Model backgrounds in control regions before analyzing the signal region. The results presented here are obtained in events where we firstly identify two electrons and then select an additional electron or muon as a third lepton. The data are used to constrain the SUSY parameter space.

Griffiths, Martin

2005-04-01

195

Diseño y prueba de un sistema de control de espaciamiento y potencia para Micro-EDM  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish Una vertiente en la evolución de los procesos de manufactura contempla reducir el tamaño de la máquina herramienta de manera proporcional al tamaño de la pieza de trabajo. Las nuevas propuestas para los procesos de micro-manufactura, como micro-EDM (micro-Electrical Discharge Machining), requieren d [...] e parámetros de proceso hasta ahora poco explorados para realizar tareas que demandan alta precisión y productividad. En este trabajo se presenta el desarrollo de un sistema de control de espaciamiento (gap) y de suministro de potencia para realizar procesos de manufactura mediante micro-EDM. Con el objetivo de explorar los valores de los parámetros de manufactura que permitieran mayor remoción de material se utilizó el diseño de experimentos Taguchi. La configuración experimental utiliza un sistema de control acoplado a un circuito RC para controlar el espaciamiento entre el electrodo y la pieza de trabajo, además de un electrodo de cobre de 0.7mm de diámetro. Abstract in english A trend in the evolution of manufacturing processes shows a tendency towards the reduction of the size of the machine tool in a manner proportional to the size of part. Emerging technologies such as micro EDM require process parameters that have been seldom explored in the literature, to perform tas [...] ks that require high precision and productivity. This article presents the development of a circuit for power supply and gap control for micro EDM. To test the circuit, the selection of process parameters that maximize removal rates was explored using a Taguchi experimental design. The experimental confi guration of the micro EDM process used 0.7 mm copper electrodes, controlled by a micro-controller based RC circuit.

Chaides, Oscar; Horacio, Ahuett; Abiud, Flores; Alberto, Caballero; Leopoldo, Ruiz.

196

CP violating electron-nucleon interactions in multi-Higgs doublet and leptoquark models  

International Nuclear Information System (INIS)

CP violating electron-nucleon interactions and the resulting atomic electric dipole moments (EDM) are studied in several models. It is demonstrated that in the standard model these interactions are very small and are well below the experimental upper bounds. In multi-Higgs doublet models, the four-fermi interactions, can be quite large. In some range of parameters, the contribution of these interactions to the atomic EDM can exceed the contribution of the electron EDM. In leptoquark models the contribution from the tensor interaction is always the dominant one. 20 refs

1992-01-01

197

Measurement of the electron electric dipole moment using GdIG  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A new method for the detection of the electron edm using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the samples magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron edm of 5E-24 e-cm, which is a factor of 40 below the limit obtained from the only previous solid-state edm experiment. The result is limited by the imperfect disc...

Heidenreich, B. J.; Elliott, O. T.; Charney, N. D.; Virgien, K. A.; Bridges, A. W.; Mckeon, M. A.; Peck, S. K.; Krause, Jr; Gordon, J. E.; Hunter, L. R.; Lamoreaux, S. K.

2005-01-01

198

Measurement of the electron electric dipole moment using GdIG  

CERN Document Server

A new method for the detection of the electron edm using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the samples magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron edm of 5E-24 e-cm, which is a factor of 40 below the limit obtained from the only previous solid-state edm experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization.

Heidenreich, B J; Charney, N D; Virgien, K A; Bridges, A W; McKeon, M A; Peck, S K; Krause, D; Gordon, J E; Hunter, L R; Lamoreaux, S K

2005-01-01

199

Limit on the Electron Electric Dipole Moment in Gadolinium-Iron Garnet  

International Nuclear Information System (INIS)

A new method for the detection of the electron electric dipole moment (EDM) using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the sample's magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron EDM of 5x10-24e cm, which is a factor of 40 below the limit obtained from the only previous solid-state EDM experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization

2005-12-16

200

Pengaruh Arc On dan Arc Off Time Terhadap Kekasaran Permukaan dan Laju Pembuangan Geram Hasil Pemesinan Sinking EDM  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Sinking type electro discharge machine (EDM) is the nwst popular non conventional machining method in the current decade based on modern CNC controlled. Although the EDM process has been used for decades, it is still widely misunderstood by many in manufacturing. The EDM is used when the work piece material is too hard, or the shape or location of the detail cannot easily be conventionally machined e.g. high precision mold and die with high surface quality. The performance of this process can...

Suhardjono Suhardjono

2004-01-01

 
 
 
 
201

Search for scalar and vector leptoquarks in electron-proton collisions at ?S = 300 GeV  

International Nuclear Information System (INIS)

A search for a resonant state coupled to an electron-quark pair has been performed using collisions of the electron beam of 26.7 GeV and the proton beam of 820 GeV. With the integrated luminosity of 26.6 ± 1.6 nb-1, scalar and vector leptoquarks have been searched for in the neutral current and charged current samples. The selected events agreed well with the prediction of the Standard Model, and no evidence has been found for production of leptoquarks decaying into e- + jet or ? + jet. Limits on the coupling strength of scalar (vector) leptoquarks to electron and quark have been determined for masses from 50 (40) GeV to 225 GeV. A limit on the leptoquark mass has been also obtained at the 95% confidence level assuming that either left-handed or right-handed coupling exists to the electron-quark pair with electroweak strength. The mass limit depends on the cross section determined by the choice of quantum numbers. Leptoquarks are ruled out for masses below 216 GeV with the largest cross section and below 105 GeV with the smallest cross section. (author) 102 refs

1993-01-01

202

Searching for Kaluza-Klein Dark Matter Signatures in the LAT Electron Flux  

CERN Document Server

We present here the prospects for the GLAST Large Area Telescope (LAT) detection of the signature of the lightest Kaluza-Klein particle (LKP). It decays by direct annihilation into electron-positron pairs that may be detectable in the high energy electron flux. We discuss the LAT capability for detecting the high energy (20 GeV - ~1 TeV) cosmic ray electron flux and we analyze the LAT sensitivity to detect LKP-produced electrons for various particle masses. We include an analysis of the diffusive propagation of the electrons in the galaxy.

Moiseev, A A; Ormes, J F; Titarchuk, L G

2007-01-01

203

A search for strong-field direct two electron ionization using coincidence spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

We report on our program in detecting two-electron ionization using electron-electron and electron-ion coincidence measurements. The coincidence techniques have been applied to the multiphoton ionization (MPI) of xenon atoms with 0.527 [mu]m excitation. The results show that direct two electron ionization is not occurring which is in variance with an earlier report. We also present a polarization study on the MPI of helium at 0.62 [mu]m and discuss these results in context of existing models.

Agostini, P.; Mevel, E.; Breger, P. (CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Service de Recherches sur les Surfaces et de l' Irradiation de la Matiere); Walker, B.; Yang, B.; DiMauro, L.F. (Brookhaven National Lab., Upton, NY (United States))

1993-01-01

204

A search for strong-field direct two electron ionization using coincidence spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

We report on our program in detecting two-electron ionization using electron-electron and electron-ion coincidence measurements. The coincidence techniques have been applied to the multiphoton ionization (MPI) of xenon atoms with 0.527 {mu}m excitation. The results show that direct two electron ionization is not occurring which is in variance with an earlier report. We also present a polarization study on the MPI of helium at 0.62 {mu}m and discuss these results in context of existing models.

Agostini, P.; Mevel, E.; Breger, P. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Service de Recherches sur les Surfaces et de l`Irradiation de la Matiere; Walker, B.; Yang, B.; DiMauro, L.F. [Brookhaven National Lab., Upton, NY (United States)

1993-05-01

205

Electronic Serials Usage Patterns as Observed at a Medium-Size University: Searches and Full-Text Downloads  

Directory of Open Access Journals (Sweden)

Full Text Available while library budgets remain either stagnant or on the decrease, it becomesnecessary to evaluate the use of a library's electronic collection. In 2006, usagestatistics were evaluated at Laurentian University, Canada, to provide direction tocollection development and identify high-cost low-use electronic serials.Searches and full-text downloads were studied. A sharp increase in use wasobserved in and around 2004 which can be explained by the introduction, inOntario, of the 'double cohort', by the rapid increase in the number of electronicresources subscribed to at Laurentian, and by the adoption of OpenURLtechnology. Heavily used electronic serials are identified. Turnaways,connections by IP address and Bradford's 20:80 rule are also examined. Theapplication of a cost-per-download ratio provided a practical method foridentifying underused products.

Alain Lamothe

2008-06-01

206

Search for excited and exotic electrons i the e? decay channel in ppbar collisions at ? s = 1.96 Tev  

International Nuclear Information System (INIS)

We present a search for excited and exotic electrons (e*) decaying to an electron and a photon, both with high transverse momentum. We use 202 pb-1 of data collected in p(bar p) collisions at ?s = 1.96 TeV with the CDF II detector. No signal above standard model expectation is seen for associated ee* production. We discuss the e* sensitivity in the parameter space of the excited electron mass Me* and the compositeness energy scale ?. In the contact interaction model, we exclude 132 GeV/c2 e* 2 for ? = Me* at 95% confidence level (C.L.). In the gauge-mediated model, we exclude 126 GeV/c2 e* 2 at 95% C.L. for the phenomenological coupling f/? ? 10-2 GeV-1

2005-01-01

207

The generalized simulated annealing algorithm in the low energy electron diffraction search problem  

International Nuclear Information System (INIS)

We present in this work results concerning the application of the generalized simulated annealing (GSA) algorithm to the LEED search problem. The influence of the visiting distribution function (defined by the so-called qV parameter) in the effectiveness of the method was investigated by the application of the algorithm to structural searches for optimization of two to ten parameters in a theory-theory comparison for the CdTe(110) system. Results, obtained with the scaling relation and probability of convergence as a function of the number of parameters to be varied, indicate the fast simulated annealing (FSA) (qV = 2.0) approach as the best search machine

2005-01-12

208

Search for Electron Neutrino Appearance at the ?m2?1 eV2 Scale  

International Nuclear Information System (INIS)

The MiniBooNE Collaboration reports first results of a search for ?e appearance in a ?? beam. With two largely independent analyses, we observe no significant excess of events above the background for reconstructed neutrino energies above 475 MeV. The data are consistent with no oscillations within a two-neutrino appearance-only oscillation model

2007-06-08

209

Optimization of Electrical and Non Electrical Factors in EDM for Machining Die Steel Using Copper Electrode by Adopting Taguchi Technique  

Digital Repository Infrastructure Vision for European Research (DRIVER)

EDM machining is used for very hard and complex cutting of conducting materials with higher surface finish and close dimensions. EDM process parameters are affected by both electrical and non electrical parameters. In these paper cutting of hard material high carbon high chromium (HCHcr) D3 steel is done on electro discharge machine with copper as cutting tool electrode. This paper presents a work on the performance parameter optimization for material removal rate (MRR) and electrode wear rat...

2013-01-01

210

Identifying quality improvement intervention publications - A comparison of electronic search strategies  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The evidence base for quality improvement (QI interventions is expanding rapidly. The diversity of the initiatives and the inconsistency in labeling these as QI interventions makes it challenging for researchers, policymakers, and QI practitioners to access the literature systematically and to identify relevant publications. Methods We evaluated search strategies developed for MEDLINE (Ovid and PubMed based on free text words, Medical subject headings (MeSH, QI intervention components, continuous quality improvement (CQI methods, and combinations of the strategies. Three sets of pertinent QI intervention publications were used for validation. Two independent expert reviewers screened publications for relevance. We compared the yield, recall rate, and precision of the search strategies for the identification of QI publications and for a subset of empirical studies on effects of QI interventions. Results The search yields ranged from 2,221 to 216,167 publications. Mean recall rates for reference publications ranged from 5% to 53% for strategies with yields of 50,000 publications or fewer. The 'best case' strategy, a simple text word search with high face validity ('quality' AND 'improv*' AND 'intervention*' identified 44%, 24%, and 62% of influential intervention articles selected by Agency for Healthcare Research and Quality (AHRQ experts, a set of exemplar articles provided by members of the Standards for Quality Improvement Reporting Excellence (SQUIRE group, and a sample from the Cochrane Effective Practice and Organization of Care Group (EPOC register of studies, respectively. We applied the search strategy to a PubMed search for articles published in 10 pertinent journals in a three-year period which retrieved 183 publications. Among these, 67% were deemed relevant to QI by at least one of two independent raters. Forty percent were classified as empirical studies reporting on a QI intervention. Conclusions The presented search terms and operating characteristics can be used to guide the identification of QI intervention publications. Even with extensive iterative development, we achieved only moderate recall rates of reference publications. Consensus development on QI reporting and initiatives to develop QI-relevant MeSH terms are urgently needed.

Rubenstein Lisa V

2011-08-01

211

Effect of Surface Quality of Brass Coating Wire on Wire EDM Characteristics  

Science.gov (United States)

The purpose of this study is to develop a new type of wire electrode, in which piano wire with very high tensile strength is coated with electrically conductive layer, such as brass or zinc, in order to attain high speed and high precision wire EDM. In this report, using a trial-made thin wire of 50?m in diameter, the optimum thickness and quality of brass layer were experimentally investigated for higher performance fine wire EDM. Furthermore, the influence of the tensile strength of piano wire used as a core wire was discussed. As a result, the coated brass with copper content of 60-70% is effective and the thickness of coated brass is needed to be more than 1.45?m for high removal rate.

Okada, Akira; Yamauchi, Toshiyuki; Arizono, Kimihiko; Uno, Yoshiyuki

212

On-line collection and transfer of radioactive noble gas isotopes for radon EDM measurements  

Science.gov (United States)

An apparatus has been developed for on--line collection and transfer to a measurement cell of radon isotopes for optical pumping studies and electric dipole moment (EDM) measurements. Specific isotopes are predicted to have large atomic EDMs due to nuclear octupole deformation or vibration resulting in enhanced sensitivity to CP violation. A low energy isotope separator beam is stopped in a foil. After collection, the foil is heated and the noble gas atoms are cryopumped to a cold finger and then transferred with a buffer gas to a measurement cell. The apparatus has been tested with ^120Xe produced from a ^120Cs beam at the TRIUMF ISAC facility, and greater than 40% efficiency for transfer from the foil to the cell has been demonstrated. The apparatus may also be useful for other measurements with gaseous targets including laser spectroscopy and precision half--life measurements.

Nuss-Warren, Sarah; Tardiff, Eric; Warner, Tim; Ball, Gordon; Behr, John; Chupp, Tim; Coulter, Kevin; Hackman, Greg; Hayden, Michael; Pearson, Matthew; Phillips, Andrew; Smith, Martin; Svensson, Carl

2004-05-01

213

Erosion Rate, Surface Finish and Electrode Wear in Electric Discharge Machining (EDM) of Dental Alloys.  

Canada Institute for Scientific and Technical Information (Canada)

A precise fit of dental restorations is critical in all aspects of prosthetic dentistry. Fabrication of a prosthesis with a high degree of accuracy is difficult due to the dimensional changes of different dental materials. EDM is an extremely accurate non-contact machining process with a precision as small as 0.002 mm. The objectives of this study were to investigate how changes in amperage and on-time of the EDM process affect the metal removal rate (MRR) and surface finish (Ra) of representative dental materials. The percentage of electrode wear (PEW) of representative electrode materials in different metal-electrode combinations was also studied. Three representative dental metals (workpieces) were used; Type III gold (Ney), Olympia ceramo-metal Alloy (Jelenko) and titanium (Ti) (Rematitan). Type III gold and ceramometal alloy were cast in bars 6mm square and 30 mm in length. Ti ingots were used as provided by manufacturer.

1997-01-01

214

Micro-hole machining using micro-EDM combined with electropolishing  

Science.gov (United States)

This paper presents a novel process of using micro-electro-discharge- machining (micro-EDM) combined with electropolishing to improve the surface roughness of micro-holes. During the machining process, a tool is fabricated by wire electro-discharge grinding (WEDG) directly by using micro-EDM for machining the micro-hole and by electropolishing to finish the hole wall. In this work, various micro-holes are machined on the high nickel alloy. By the electropolishing method, high surface quality of the hole wall is obtained by applying a suitable electrolytic voltage and an appropriate concentration of electrolyte in about 5 min of machining time. The taper and burrs of the inlet of holes are reduced, even for difficult- to-machine special-shaped micro-holes. The surface roughness reduced from 2.11 µm Rmax before grinding to 0.69 µm Rmax after electropolishing.

Hung, Jung-Chou; Yan, Biing-Hwa; Liu, Hung-Sung; Chow, Han-Ming

2006-08-01

215

EDM, SCC defect depth analysis using a multi-parameter algorithm  

International Nuclear Information System (INIS)

Eddy Current Testing (ECT) is a nondestructive technique. It is used for an evaluation of a materials' integrity, especially, Steam Generator (SG) tubing in nuclear plants, due to its rapid inspection, safe and easy operation. For the depth measurement of defects, Electro Discharge Machined (EDM) notches that have several defects are prepared, and the Multi-Parameter Algorithm (MPA) was applied. We analyzed the Stress Corrosion Crack (SCC) of a tube pulled out from a Retired Steam Generator (RSG) of the Kori-1. The MPA is a crack shape estimation program developed in Argonne National Laboratory (ANL). To evaluate the MP algorithm, we compared the defect profile with the fractography of the defect. In the following sections, the basic structure of the computer-aided data analysis algorithm used as a means of a more accurate and efficient processing of the ECT data, and the defects depth analysis results of the EDM and SCC are described

2005-05-26

216

Integration of micro milling highspeed spindle on a microEDM-milling machine set-up  

DEFF Research Database (Denmark)

In order to cope with repositioning errors and to combine the fast removal rate of micro milling with the precision and small feature size achievable with micro EDM milling, a hybrid micro-milling and micro-EDM milling centre was built and tested. The aim was to build an affordable set-up, easy to use and adapt to an existing device, not to build a complete new machine. The design requirements will be presented and the set-up described. A geometrical model of the set-up following the small displacement torsor concept is proposed and verified by comparing a simulated and manufactured pocket done by micro milling. Examples of test parts are shown and used as an experimental validation.

De Grave, Arnaud; Hansen, Hans Nørgaard

2009-01-01

217

The Influence of EDM Parameters in Finishing Stage on Surface Quality, MRR and EWR  

Directory of Open Access Journals (Sweden)

Full Text Available The adequate selection of manufacturing conditions is one of the most important aspects to take into consideration in the die-sinking Electrical Discharge Machining (EDM of conductive martial, as these conditions are the ones that are to determine such important characteristics as: surface roughness, Electrode Wear Ratio (EWR and Material Removal Rate(MRR, among others. In this research, the influence of different EDM parameters (current, pulse on-time, pulse off-time, arc voltage on the surface quality ,material removal rate and electrode wear ratio as a result of application copper electrode to cold work steel DIN1.2379 has been investigated. Design of the experiments was chosen full factorial in finishing stage. Finally, the artificial neural network has been employed to predict the surface quality, material removal rate and electrode wear ratio. The experiment results indicated a good performance of proposed method in optimization of such a complex and non-linear problems.

Reza Atefi

2012-05-01

218

Electron identification and reconstruction with the OPERA ECC bricks and search for muon neutrino to electron neutrino oscillations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The procedure for event location in OPERA ECC has been optimazed for penetrating particles while is less efficient for electrons. For this reason new procedure has been defined in order to recover event with an electromagnetic shower in its final state not located with the standard one. The new procedure include the standard procedure during which several electromagnetic shower hint has been defined by means of the available data. In case the event is not located, the presence of an ele...

Tenti, Matteo

2012-01-01

219

Perspective of edm method for creation of construction units from single and polycrystal silicon  

International Nuclear Information System (INIS)

In this paper the new EDM method in non-conventional field its employment is proposed the problem of manufacture holes and spaces in high-ohm material is considered as an example, this method was used for broaching holes and spaces in body of silicon specular reflectors which intended for operation under laser and concentrated solar radiation in solar cells of large single-unit power and also for conversion of concentrated solar radiation. (author)

1999-01-01

220

Feasibility of wear compensation in micro EDM milling based on discharge counting and discharge population characterization  

DEFF Research Database (Denmark)

This paper investigates the applicability of real time wear compensation in micro EDM milling based on discharge counting and discharge population characterization. Experiments were performed involving discharge counting and tool electrode wear measurement in a wide range of process parameters settings involving different current pulse shapes. A strong correlation is found between average discharge energy of the populations and wear and material removal per discharge. A validation was carried out showing the feasibility of the proposed approach.

Bissacco, Giuliano; Hansen, Hans Nørgaard

2011-01-01

 
 
 
 
221

Search for heavy particles decaying into electron-positron pairs in p-pbar collisions  

CERN Document Server

We present results of searches for technirho, techniomega, and Z' particles, using the decay channels technirho, techniomega, Z' -> e+e-. The search is based on 124.8 pb-1 of data collected by the D0 detector at the Fermilab Tevatron during 1992-1996. In the absence of a signal, we set 95% C.L. upper limits on the cross sections for the processes p pbar -> technirho, techniomega, Z' -> e+e- as a function of the mass of the decaying particle. For certain model parameters, we exclude the existence of degenerate technirho and techniomega states with masses below about 200 GeV. We exclude a Z' with mass below 670 GeV, assuming that it has the same couplings to fermions as the Z boson.

Abazov, V M; Abdesselam, A; Abolins, M; Abramov, V; Acharya, B S; Adams, D L; Adams, M; Ahmed, S N; Alexeev, G D; Alves, G A; Amos, N; Anderson, E W; Baarmand, M M; Babintsev, V V; Babukhadia, L R; Bacon, Trevor C; Baden, A; Baldin, B Yu; Balm, P W; Todorova-Nová, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Begel, M; Belyaev, A; Beri, S B; Bernardi, G; Bertram, I; Besson, A; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Blazey, G C; Blessing, S; Böhnlein, A; Bozhko, N; Borcherding, F; Bos, Kors; Brandt, A; Breedon, R; Briskin, G M; Brock, R; Brooijmans, G; Bross, A; Buchholz, D; Bühler, M; Büscher, V; Burtovoi, V S; Butler, J M; Canelli, F; Carvalho, W S; Casey, D; Casilum, Z; Castilla-Valdez, H; Chakraborty, D; Chan, K M; Chekulaev, S V; Cho, D K; Choi, S; Chopra, S; Christenson, J H; Chung, M; Claes, D; Clark, A R; Cochran, J; Coney, L; Connolly, B; Cooper, W E; Coppage, D; Cummings, M A C; Cutts, D; Davis, G A; Davis, K; De, K; De Jong, S J; Del Signore, K; Demarteau, M; Demina, R; Demine, P; Denisov, D S; Denisov, S P; Desai, S V; Diehl, H T; Diesburg, M; DiLoreto, G; Doulas, S; Draper, P; Ducros, Y; Dudko, L V; Duensing, S; Duflot, L; Dugad, S R; Dyshkant, A; Edmunds, D; Ellison, J; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Estrada, J; Evans, H; Evdokimov, V N; Fahland, T; Fehér, S; Fein, D; Ferbel, T; Filthaut, Frank; Fisk, H E; Fisyak, Yu; Flattum, E M; Fleuret, F; Fortner, M R; Frame, K C; Fuess, S; Gallas, E; Galjaev, A N; Gao, M; Gavrilov, V; Genik, R J; Genser, K; Gerber, C E; Gershtein, Yu; Gilmartin, R; Ginther, G; Gómez, B; Gómez, G; Goncharov, P I; González-Solis, J L; Gordon, H; Goss, L T; Gounder, K; Goussiou, A; Graf, N; Graham, G; Grannis, P D; Green, J A; Greenlee, H; Grinstein, S; Groer, L S; Grünendahl, S; Sen-Gupta, A; Gurzhev, S N; Gutíerrez, G; Gutíerrez, P; Hadley, N J; Haggerty, H; Hagopian, S L; Hagopian, V; Hall, R E; Hanlet, P; Hansen, S; Hauptman, J M; Hays, C; Hebert, C; Hedin, D; Heinson, A P; Heintz, U; Heuring, T C; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Huang, Y; Illingworth, R; Ito, A S; Jaffré, M; Jain, S; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jones, M; Jöstlein, H; Juste, A; Kahn, S; Kajfasz, E; Kalinin, A M; Karmanov, D E; Karmgard, D J; Kehoe, R; Kharchilava, A I; Kim, S K; Klima, B; Knuteson, B; Ko, W; Kohli, J M; Kostritskii, A V; Kotcher, J; Kotwal, A V; Kozelov, A V; Kozlovskii, E A; Krane, J; Krishnaswamy, M R; Krivkova, P; Krzywdzinski, S; Kubantsev, M A; Kuleshov, S; Kulik, Y; Kunori, S; Kupco, A; Kuznetsov, V E; Landsberg, G L; Leflat, A; Leggett, C; Lehner, F; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linn, S L; Linnemann, J T; Lipton, R; Lucotte, A; Lueking, L H; Lundstedt, C; Luo, C; Maciel, A K A; Madaras, R J; Malyshev, V L; Manankov, V; Mao, H S; Marshall, T; Martin, M I; Martin, R D; Mauritz, K M; May, B; Mayorov, A A; McCarthy, R; McDonald, J; McMahon, T; Melanson, H L; Merkin, M; Merritt, K W B; Miao, C; Miettinen, H; Mihalcea, D; Mishra, C S; Mokhov, N V; Mondal, N K; Montgomery, H E; Moore, R W; Mostafa, M A; Da Motta, H; Nagy, E; Nang, F; Narain, M; Narasimham, V S; Neal, H A; Negret, J P; Negroni, S; Nunnemann, T; O'Neil, D C; Oguri, V; Olivier, B; Oshima, N; Padley, P; Pan, L J; Papageorgiou, K; Para, A; Parashar, N; Partridge, R; Parua, N; Paterno, M; Patwa, A; Pawlik, B; Perkins, J; Peters, M; Peters, O; Petroff, P; Piegaia, R; Piekarz, H; Pope, B G; Popkov, E; Prosper, H B; Protopopescu, S D; Qian, J; Raja, R; Rajagopalan, S; Ramberg, E; Rapidis, P A; Reay, N W; Reucroft, S; Rha, J; Ridel, M; Rijssenbeek, M; Rockwell, T; Roco, M T; Rubinov, P; Ruchti, R C; Rutherfoord, John P; Sabirov, B M; Santoro, A F S; Sawyer, L; Schamberger, R D; Schellman, H; Schwartzman, A; Sen, N; Shabalina, E; Shivpuri, R K; Shpakov, D; Shupe, M A; Sidwell, R A; Simák, V; Singh, H; Singh, J B; Sirotenko, V I; Slattery, P F; Smith, E; Smith, R P; Snihur, R; Snow, G A; Snow, J; Snyder, S; Solomon, J; Sorin, V; Sosebee, M; Sotnikova, N; Soustruznik, K; Souza, M; Stanton, N R; Steinbruck, G; Stephens, R W; Stichelbaut, F; Stoker, D; Stolin, V; Stoyanova, D A; Strauss, M; Strovink, M; Stutte, L; Sznajder, A; Taylor, W; Tentindo-Repond, S; Tripathi, S M; Trippe, T G; Turcot, A S; Tuts, P M; Van Gemmeren, P; Vaniev, V; Van Kooten, R; Varelas, N; Vertogradov, L S; Volkov, A A; Vorobev, A P; Wahl, H D; Wang, H; Wang, Z M; Warchol, J; Watts, G; Wayne, M; Weerts, H; White, A; White, J T; Whiteson, D; Wightman, J A; Wijngaarden, D A; Willis, S; Wimpenny, S J; Womersley, J; Wood, D R; Yamada, R; Yamin, P; Yasuda, T; Yatsunenko, Yu A; Yip, K; Youssef, S; Yu, J; Yu, Z; Zanabria, M E; Zheng, H; Zhou, Z; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G; Zylberstejn, A

2001-01-01

222

Search for heavy particles decaying into electron-positron pairs in pp collisions.  

Science.gov (United States)

We present results of searches for technirho (rho(T)), techniomega (omega(T)), and Z' particles, using the decay channels rho(T),omega(T),Z'-->e(+)e(-). The search is based on 124.8 pb(-1) of data collected by the D0 detector at the Fermilab Tevatron during 1992-1996. In the absence of a signal, we set 95% C.L. upper limits on the cross sections for the processes pp-->rho(T),omega(T),Z'-->e(+)e(-) as a function of the mass of the decaying particle. For certain model parameters, we exclude the existence of degenerate rho(T) and omega(T) states with masses below about 200 GeV. We exclude a Z' with mass below 670 GeV, assuming that it has the same couplings to fermions as the Z boson. PMID:11497822

Abazov, V M; Abbott, B; Abdesselam, A; Abolins, M; Abramov, V; Acharya, B S; Adams, D L; Adams, M; Ahmed, S N; Alexeev, G D; Alves, G A; Amos, N; Anderson, E W; Baarmand, M M; Babintsev, V V; Babukhadia, L; Bacon, T C; Baden, A; Baldin, B; Balm, P W; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Begel, M; Belyaev, A; Beri, S B; Bernardi, G; Bertram, I; Besson, A; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Blazey, G; Blessing, S; Boehnlein, A; Bojko, N I; Borcherding, F; Bos, K; Brandt, A; Breedon, R; Briskin, G; Brock, R; Brooijmans, G; Bross, A; Buchholz, D; Buehler, M; Buescher, V; Burtovoi, V S; Butler, J M; Canelli, F; Carvalho, W; Casey, D; Casilum, Z; Castilla-Valdez, H; Chakraborty, D; Chan, K M; Chekulaev, S V; Cho, D K; Choi, S; Chopra, S; Christenson, J H; Chung, M; Claes, D; Clark, A R; Cochran, J; Coney, L; Connolly, B; Cooper, W E; Coppage, D; Cummings, M A; Cutts, D; Davis, G A; Davis, K; De, K; de Jong, S J; Del Signore, K; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Di Loreto, G; Doulas, S; Draper, P; Ducros, Y; Dudko, L V; Duensing, S; Duflot, L; Dugad, S R; Dyshkant, A; Edmunds, D; Ellison, J; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Estrada, J; Evans, H; Evdokimov, V N; Fahland, T; Feher, S; Fein, D; Ferbel, T; Filthaut, F; Fisk, H E; Fisyak, Y; Flattum, E; Fleuret, F; Fortner, M; Frame, K C; Fuess, S; Gallas, E; Galyaev, A N; Gao, M; Gavrilov, V; Genik, R J; Genser, K; Gerber, C E; Gershtein, Y; Gilmartin, R; Ginther, G; Gómez, B; Gómez, G; Goncharov, P I; González Solís, J L; Gordon, H; Goss, L T; Gounder, K; Goussiou, A; Graf, N; Graham, G; Grannis, P D; Green, J A; Greenlee, H; Grinstein, S; Groer, L; Grünendahl, S; Gupta, A; Gurzhiev, S N; Gutierrez, G; Gutierrez, P; Hadley, N J; Haggerty, H; Hagopian, S; Hagopian, V; Hall, R E; Hanlet, P; Hansen, S; Hauptman, J M; Hays, C; Hebert, C; Hedin, D; Heinson, A P; Heintz, U; Heuring, T; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Huang, Y; Illingworth, R; Ito, A S; Jaffré, M; Jain, S; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jones, M; Jöstlein, H; Juste, A; Kahn, S; Kajfasz, E; Kalinin, A M; Karmanov, D; Karmgard, D; Kehoe, R; Kharchilava, A; Kim, S K; Klima, B; Knuteson, B; Ko, W; Kohli, J M; Kostritskiy, A V; Kotcher, J; Kotwal, A V; Kozelov, A V; Kozlovsky, E A; Krane, J; Krishnaswamy, M R; Krivkova, P; Krzywdzinski, S; Kubantsev, M; Kuleshov, S; Kulik, Y; Kunori, S; Kupco, A; Kuznetsov, V E; Landsberg, G; Leflat, A; Leggett, C; Lehner, F; Li, J; Li, Q Z; Lima, J G; Lincoln, D; Linn, S L; Linnemann, J; Lipton, R; Lucotte, A; Lueking, L; Lundstedt, C; Luo, C; Maciel, A K; Madaras, R J; Malyshev, V L; Manankov, V; Mao, H S; Marshall, T; Martin, M I; Martin, R D; Mauritz, K M; May, B; Mayorov, A A; McCarthy, R; McDonald, J; McMahon, T; Melanson, H L; Merkin, M; Merritt, K W; Miao, C; Miettinen, H; Mihalcea, D; Mishra, C S; Mokhov, N; Mondal, N K; Montgomery, H E; Moore, R W; Mostafa, M; da Motta, H; Nagy, E; Nang, F; Narain, M; Narasimham, V S; Neal, H A; Negret, J P; Negroni, S; Nunnemann, T; O'Neil, D; Oguri, V; Olivier, B; Oshima, N; Padley, P; Pan, L J; Papageorgiou, K; Para, A; Parashar, N; Partridge, R; Parua, N; Paterno, M; Patwa, A; Pawlik, B; Perkins, J; Peters, M; Peters, O; Pétroff, P; Piegaia, R; Piekarz, H; Pope, B G; Popkov, E; Prosper, H B; Protopopescu, S; Qian, J; Raja, R; Rajagopalan, S; Ramberg, E; Rapidis, P A; Reay, N W; Reucroft, S; Rha, J; Ridel, M; Rijssenbeek, M; Rockwell, T; Roco, M; Rubinov, P; Ruchti, R; Rutherfoord, J; Sabirov, B M; Santoro, A; Sawyer, L; Schamberger, R D; Schellman, H; Schwartzman, A; Sen, N; Shabalina, E; Shivpuri, R K; Shpakov, D; Shupe, M; Sidwell, R A; Simak, V; Singh, H; Singh, J B; Sirotenko, V; Slattery, P; Smith, E; Smith, R P; Snihur, R; Snow, G R; Snow, J; Snyder, S; Solomon, J; Sorín, V; Sosebee, M; Sotnikova, N; Soustruznik, K; Souza, M; Stanton, N R; Steinbrück, G; Stephens, R W; Stichelbaut, F; Stoker, D; Stolin, V; Stoyanova, D A; Strauss, M; Strovink, M; Stutte, L; Sznajder, A; Taylor, W; Tentindo-Repond, S; Tripathi, S M; Trippe, T G; Turcot, A S; Tuts, P M; van Gemmeren, P; Vaniev, V; Van Kooten, R; Varelas, N; Vertogradov, L S; Volkov, A A; Vorobiev, A P; Wahl, H D; Wang, H; Wang, Z M; Warchol, J; Watts, G; Wayne, M; Weerts, H; White, A; White, J T; Whiteson, D; Wightman, J A; Wijngaarden, D A; Willis, S; Wimpenny, S J; Womersley, J; Wood, D R; Yamada, R; Yamin, P; Yasuda, T; Yatsunenko, Y A; Yip, K; Youssef, S; Yu, J; Yu, Z; Zanabria, M; Zheng, H; Zhou, Z; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G; Zylberstejn, A

2001-08-01

223

Order of Magnitude Smaller Limit on the Electric Dipole Moment of the Electron  

CERN Document Server

The Standard Model (SM) of particle physics is known to be incomplete. It fails to explain dark matter, and why matter survived annihilation with antimatter following the Big Bang. Proposed extensions to the SM, such as weak-scale Supersymmetry (SUSY), may explain these phenomena by positing the existence of new particles and new interactions that are not symmetric under the time-reversal (T) transformation. These same theories nearly always predict a small, yet potentially measurable, asymmetric charge distribution directed along the spin ($\\vec{S}$) of the electron, an electric dipole moment (EDM, $\\vec{d_e}=d_e \\vec{S}/(\\hbar/2)$), which is also asymmetric under T. The predicted value of $d_e$ in these SM extensions is typically in the range of $10^{-27}$-$10^{-30}$ $e$ cm, orders of magnitude larger than is predicted by the SM. Here, we report a new search for the electron EDM using the polar molecule thorium monoxide (ThO). Our result, $d_e = (-2.1 \\pm 3.7_\\mathrm{stat} \\pm 2.5_\\mathrm{syst})\\times 10^{-...

Baron, Jacob; DeMille, David; Doyle, John M; Gabrielse, Gerald; Gurevich, Yulia V; Hess, Paul W; Hutzler, Nicholas R; Kirilov, Emil; Kozyryev, Ivan; O'Leary, Brendon R; Panda, Cristian D; Petrik, Elizabeth S; Spaun, Ben; Vutha, Amar C; West, Adam D

2014-01-01

224

Linear programming analysis of the $R$-parity violation within EDM-constraints  

CERN Document Server

The constraint on the $R$-parity violating supersymmetric interactions is discussed in the light of current experimental data of the electric dipole moment of neutron, $^{129}$Xe , $^{205}$Tl, and $^{199}$Hg atoms, and YbF and ThO molecules. To investigate the constraints without relying upon the assumption of the dominance of a particular combination of couplings over all the rest, an extensive use is made of the linear programming method in the scan of the parameter space. We give maximally possible values for the EDMs of the proton, deuteron, $^3$He nucleus, $^{211}$Rn, $^{225}$Ra, $^{210}$Fr, and the $R$-correlation of the neutron beta decay within the constraints from the current experimental data of the EDMs of neutron, $^{129}$Xe, $^{205}$Tl, and $^{199}$Hg atoms, and YbF and ThO molecules using the linear programming method. It is found that the $R$-correlation of the neutron beta decay and hadronic EDMs are very useful observables to constrain definite regions of the parameter space of the $R$-parity...

Yamanaka, Nodoka; Kubota, Takahiro

2014-01-01

225

A high-efficiency approach for fabricating mass micro holes by batch micro EDM  

Science.gov (United States)

This work is a follow-up study based on previous research. The study presents a novel approach for effective production of mass micro holes. Initially, a set of micro w-EDM mechanisms is designed and mounted on the developed precise tabletop CNC machine tool to fabricate the micro electrode array. The tension of the micro wire is precisely controlled by a magnetic force. Furthermore, micro vibrations of the wire during discharging are effectively suppressed by the developed vibration suppression system. To fabricate the mass micro holes, a microstructure array with a high-aspect ratio of 10 × 10 micro squared electrodes, width and height of 21 µm and 700 µm, respectively, for each electrode and 24 µm spacing between two electrodes is fabricated first by using the proposed 'reverse w-EDM' machining strategy. The electrodes array is directly utilized to drill the mass micro holes by bath micro EDM on the same machine. An array of 900 through-holes of the same size is successfully fabricated via the modified peck-drilling method on a 30 µm thick stainless-steel plate. A tip at the free end of the micro electrode is designed and fabricated as a circular-pyramid shape. Experimental results verified that the spiky end form eliminates debris adhering to the edges of the micro holes. Analytical results demonstrate satisfactory hole geometric accuracy, dimensional accuracy and surface roughness. Furthermore, mass micro holes can be fabricated efficiently using the proposed technique.

Chen, Shun-Tong

2007-10-01

226

Development of a high precision tabletop versatile CNC wire-EDM for making intricate micro parts  

Science.gov (United States)

The micro-electrical discharge machining (micro-EDM) process has been proved to be appropriate for making 3D micro parts that are difficult and even impossible to manufacture by other processes. In this paper a high precision tabletop CNC wire electrical discharge machine (wire EDM) designed specifically for machining complex shape micro parts or structures is developed. In the machine developed, a novel micro-wire-cutting mechanism is designed, an approach to control wire tension by magnetic force is proposed and a servo feed control strategy, in accordance with the measured gap voltage, is designed and implemented. To verify the functions and capabilities of the machine developed, several thick micro outer and internal spur gears and rack are machined. It shows that the taper angle along the wall or cavity of a part that appears when other micro-EDM processes are applied can be avoided. A very good dimensional accuracy of 1 µm and a surface finish of Rmax equal to 0.64 µm are achieved. The satisfactory cutting of a miniature 3D pagoda with a micro-hooked structure also reveals that the machine developed is versatile, and can be used as a new tool for making intricate micro parts.

Liao, Yunn-Shiuan; Chen, Shun-Tong; Lin, Chang-Sheng

2005-02-01

227

Modeling and Analysis of MRR, EWR and Surface Roughness in EDM Milling through Response Surface Methodology  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: Electrical Discharge Machining (EDM has grown over the last few decades from a novelty to a mainstream manufacturing process. Though, EDM process is very demanding but the mechanism of the process is complex and far from completely understood. It is difficult to establish a model that can accurately predict the performance by correlating the process parameters. The optimum processing parameters are essential to increase the production rate and decrease the machining time, since the materials, which are processed by EDM and even the process is very costly. This research establishes empirical relations regarding machining parameters and the responses in analyzing the machinability of the stainless steel. Approach: The machining factors used are voltage, rotational speed of electrode and feed rate over the responses MRR, EWR and Ra. Response surface methodology was used to investigate the relationships and parametric interactions between the three controllable variables on the MRR, EWR and Ra. Central composite experimental design was used to estimate the model coefficients of the three factors. The responses were modeled using a response surface model based on experimental results. The significant coefficients were obtained by performing Analysis Of Variance (ANOVA at 95% level of significance. Results: The variation in percentage errors for developed models was found within 5%. Conclusion: The developed models show that voltage and rotary motion of electrode are the most significant machining parameters influencing MRR, EWR and Ra. These models can be used to get the desired responses within the experimental range.

A. K.M.S. Iqbal

2010-01-01

228

Aspects on the optimization of die-sinking EDM of tungsten carbide-cobalt  

Directory of Open Access Journals (Sweden)

Full Text Available At present, due to their properties, the tungsten carbide-cobalt (WC-Co composite materials are in huge demand by industry to manufacture special tools, dies/molds and components under erosion. The powder metallurgy is the usual process applied to obtain WC-Co products, but in some cases this process is unable to produce tools of very complex shapes and highly intricate details. Thus, additional conventional and non-conventional machining processes are required. In this context, the electrical discharge machining (EDM is an efficient alternative process. However, the EDM parameters have to be properly set for any different tungsten carbide-cobalt composition and electrode material to achieve an appropriate level of machining performance. In this work, a special grade of tungsten carbide-cobalt was used as workpiece and a copper-tungsten alloy as electrode. Experiments on important EDM electrical and non-electrical parameter settings with reference to material removal rate, electrode wear ratio and surface roughness were carried out under typical rough and finish machining. This paper contributes with an attempt to provide insightful guidelines to optimize electrical discharge machining of WC-Co composite materials using CuW alloy electrodes.

Fred Lacerda Amorim

2010-12-01

229

Search for new candidates for the neutrino-oriented mass determination by electron-capture  

CERN Document Server

This proposal is part of an extended program dedicated to the neutrino-mass determination in the electron-capture sector, which aims at ultra-precise mass measurements by Penning traps in combination with cryogenic micro-calorimetry for atomic de-excitation measurements. Here, precise mass measurements with ISOLTRAP are proposed for the orbital electron-capture nuclides $^{194}$Hg and $^{2o2}$Pb, as well as their daughters, with the goal to determine accurately their Q-values. These values are expected to be the smallest ones among a great variety of known electron-capture precursors. Therefore, these nuclides are strong candidates for an improved electron-neutrino mass determination. We ask for 8 shifts of on-line beam at ISOLDE for mass measurements of $^{194}$Hg, $^{194}$ Au, $^{2o2}$Pb, and $^{2o2}$Tl at ISOLTRAP.

Herfurth, F; Boehm, C; Blaum, K; Lunney, D; Beck, D; Rosenbusch, M

2008-01-01

230

Ozone absorption spectroscopy in search of low-lying electronic states  

Science.gov (United States)

A spectrometer capable of detecting ozone absorption features 9 orders of magnitude weaker than the Hartley band has been employed to investigate the molecule's near-infrared absorption spectrum. At this sensitivity a wealth of information on the low-lying electronically excited states often believed to play a role in atmospheric chemistry is available in the form of vibrational and rotational structure. We have analyzed these spectra using a combination of digital filtering and isotope substitution and find evidence for three electronically excited states below 1.5 eV. The lowest of these states is metastable, bound by approximately 0.1 eV and probably the (3)A2 rather than the (3)B2 state. Its adiabatic electronic energy is 1.24 +/- 0.01 eV, slightly above the dissociation energy of the ground state. Two higher states, at 1.29 +/- 0.03 and 1.48 +/- 0.03 eV are identified as the (3)B2 and the (3)B1, respectively. Combined with other recent theoretical and experimental data on the low-lying electronic states of ozone, these results imply that these are, in fact, the lowest three excited states; that is, there are no electronically excited states of ozone lying below the energy of O(3P) + O2((3)Sigma(-), v = 0). Some of the implications for atmospheric chemistry are considered.

Anderson, S. M.; Mauersberger, K.

1995-01-01

231

Influence of Span 20 Surfactant and Graphite Powder Added in Dielectric Fluid on EDM of Titanium Alloy  

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes an experimental study to evaluate the effect of Span20 surfactant and Graphite powder (additives added to the dielectric fluid on the machining characteristics of the Titanium alloy using Electrical Discharge Machining (EDM. Variation of material removal rate, surface roughness and tool wear rate with respect to the variation in discharge current is evaluated. Comparison is made between the performance characteristics of the Titanium alloy with and without additives added to the dielectric fluid in the machining process. Increase in Material Removal Rate (MRR and decrease in Tool Wear Rate (TWR and Surface Roughness (SR were observed, when the material is machined with additives added in the dielectric fluid compared to the machining of the alloy without additives added in the dielectric fluid. The Scanning Electron Microscope (SEM photograph observed that the recast layer thickness is low and on the machined upper surface less micro cracks and craters are formed. Energy Dispersive Spectroscopy (EDS analysis also indicates that some amounts of material were transferred from electrode to workpiece.

Murahari Kolli

2014-05-01

232

Improved search for Muon-neutrino to electron-neutrino oscillations in MINOS.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report the results of a search for ?(e) appearance in a ?(?) beam in the MINOS long-baseline neutrino experiment. With an improved analysis and an increased exposure of 8.2 × 10(20) protons on the NuMI target at Fermilab, we find that 2 sin(2) (?(23))sin(2)(2?(13))<0.12(0.20) at 90% confidence level for ? = 0 and the normal (inverted) neutrino mass hierarchy, with a best-fit of 2sin(2) (?(23))sin(2)(2?(13)) = 0.041(-0.031)(+0.047) (0.079(-0.053) (+0.071)). The ?(13) = 0 hypothesi...

Adamson, P.; Auty, Dj; Ayres, Ds; Backhouse, C.; Barr, G.; Betancourt, M.; Bishai, M.; Blake, A.; Bock, Gj; Boehnlein, Dj; Bogert, D.; Cao, Sv; Cavanaugh, S.; Cherdack, D.; Childress, S.

2011-01-01

233

Electronic Book Usage Patterns as Observed at an Academic Library: Searches and Viewings  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In 2009, e-book usage statistics were evaluated at Laurentian University, Canada, to provide a better understanding in how the e-book collection has been utilized as well as to give direction for further collection development. The number of e-books, the number of viewings and the number of searches were examined. The size of the collection grew from a single book in 2002 to more than 60,000 in 2008. The pattern of purchase varied from that of bulk purchasing of large e-book collections to a ...

Lamothe, Alain R.

2010-01-01

234

Results of a search for double positron decay and electron-positron conversion of 78Kr  

Science.gov (United States)

The results of a search for the 2? + and K? + decay modes of 78Kr, in a coincidence experiment using a high pressure ionization chamber of enriched 78Kr inside an enceinte of sodium iodine scintillators, are presented. After 4434 hours of counting time, the half-life lower limits obtained are T{1}/{2}( K? +) 0? ? 5.8×10 21y and T{1}/{2}(2? +) 0?+2? ? 2.0×10 21y at 68% C.L.

Sáenz, C.; García, E.; Klimenko, A.; Kuzminov, V.; Metlinsky, N.; Morales, A.; Morales, J.; Novikov, V.; Nuñez-Lagos, R.; Ortiz de Solórzano, A.; Pomansky, A.; Pritytchenko, V.; Puimedón, J.; Salinas, A.; Sarsa, M.; Villar, J. A.

1994-05-01

235

Search for Muon-Neutrino to Electron-Neutrino Transitions in MINOS  

International Nuclear Information System (INIS)

This Letter reports on a search for ????e transitions by the MINOS experiment based on a 3.14x1020 protons-on-target exposure in the Fermilab NuMI beam. We observe 35 events in the Far Detector with a background of 27±5(stat)±2(syst) events predicted by the measurements in the Near Detector. If interpreted in terms of ????e oscillations, this 1.5? excess of events is consistent with sin2(2?13) comparable to the CHOOZ limit when |?m2|=2.43x10-3 eV2 and sin2(2?23)=1.0 are assumed.

2009-12-31

236

Improved Search for Muon-Neutrino to Electron-Neutrino Oscillations in MINOS  

International Nuclear Information System (INIS)

We report the results of a search for ?e appearance in a ?? beam in the MINOS long-baseline neutrino experiment. With an improved analysis and an increased exposure of 8.2x1020 protons on the NuMI target at Fermilab, we find that 2sin2(?23)sin2(2?13)2(?23)sin2(2?13)=0.041-0.031+0.047(0.079-0.053+0.071). The ?13=0 hypothesis is disfavored by the MINOS data at the 89% confidence level.

2011-10-28

237

Search for Lepton Flavor Violation in the Decay tau -> electron gamma  

Energy Technology Data Exchange (ETDEWEB)

A search for the non-conservation of lepton flavor in the decay {tau}{sup {+-}} {yields} e{sup {+-}}{gamma} has been performed with 2.07 x 10{sup 8} e{sup +}e{sup -} {yields} {tau}{sup +}{tau}{sup -} events collected by the BABAR detector at the PEP-II storage ring at a center-of-mass energy near 10.58 GeV. They find no evidence for a signal and set an upper limit on the branching ratio of {Beta}({tau}{sup {+-}} {yields} e{sup {+-}}{gamma}) < 1.1 x 10{sup -7} at 90% confidence level.

Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; /Annecy, LAPP; Grauges, E.; /Barcelona, IFAE; Palano, A.; Pappagallo, M.; Pompili, A.; /Bari U. /INFN, Bari; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; /Beijing, Inst. High Energy Phys.; Eigen, G.; Ofte, I.; Stugu, B.

2005-08-26

238

Results of a search for double positron decay and electron-positron conversion of 78Kr  

International Nuclear Information System (INIS)

The preliminary results of a search for the 2?+ and K?+ in a coincidence experiment using a high pressure ionization chamber of enriched 78Kr inside a NaI scintillator are presented in this paper. After 4434 hours of counting time, the half-time limits obtained are T1/2(K?+)0??5.8*1021 y and T1/2(2?+)0?+2??2.0*1021 y at 68% C.L. These are the best world limits for the 2?+ and K?+ decay modes. (authors). 6 refs., 3 figs

1993-02-06

239

An Electron Fixed Target Experiment to Search for a New Vector Boson A' Decaying to e+e-  

CERN Document Server

We describe an experiment to search for a new vector boson A' with weak coupling alpha' > 6 x 10^{-8} alpha to electrons (alpha=e^2/4pi) in the mass range 65 MeV < m_A' < 550 MeV. New vector bosons with such small couplings arise naturally from a small kinetic mixing of the "dark photon" A' with the photon -- one of the very few ways in which new forces can couple to the Standard Model -- and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiation off an electron beam, and could appear as narrow resonances with small production cross-section in the trident e+e- spectrum. We summarize the experimental approach described in a proposal submitted to Jefferson Laboratory's PAC35, PR-10-009. This experiment, the A' Experiment (APEX), uses the electron beam of the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory (CEBAF) at energies of ~1-4 GeV incident on 0.5-10% radiation length Tungsten wire mesh targets, and me...

Essig, Rouven; Toro, Natalia; Wojtsekhowski, Bogdan

2010-01-01

240

Indirect search for color octet electron at next generation linear colliders  

CERN Document Server

In this study we investigated indirect manifestations of color octet electron at the next generation linear colliders: International Linear Collider (ILC) and Compact Linear Collider (CLIC). Namely, production of two gluons via color octet electron exchange is considered. Signal and background analysis have been performed taking into account initial state radiation and beamstrahlung. We show that color octet electron (e_(8)) manifestation will be seen upto M(e_(8))=1.75 TeV and 1.70 TeV at ILC and CLIC with sqrt(s)=0.5 TeV, respectively. CLIC with sqrt(s)=3 TeV will be sensitive upto M(e_(8)=6.88 TeV.

Akay, A N; Sahin, M; Sultansoy, S

2010-01-01

 
 
 
 
241

Slow electron scattering from Ag, Pd, Pt, Ru and Y atoms: Search for nanocatalysts  

International Nuclear Information System (INIS)

Electron elastic total cross sections (TCSs) for Ag, Pd, Pt, Ru and Y atoms are calculated in the electron energy range 0 ? E ? 7.0 eV using the complex angular momentum (CAM) method. The imaginary part of the CAM is used to distinguish between shape resonances and bound states of the negative ions formed during the collision. Using our Au TCS as the template for nanocatalysts, we conclude that these atoms represent excellent candidates for nanocatalysts individually or in various combinations.

2012-11-05

242

Search for Excited or Exotic Electron Production Using the Dielectron + Photon Signature at CDF in Run II  

Energy Technology Data Exchange (ETDEWEB)

The author presents a search for excited or exotic electrons decaying to an electron and a photon with high transverse momentum. An oppositely charged electron is produced in association with the excited electron, yielding a final state dielectron + photon signature. The discovery of excited electrons would be a first indication of lepton compositeness. They use {approx} 202 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV with the Collider Detector at Fermilab during March 2001 through September 2003. The data are consistent with standard model expectations. Upper limits are set on the experimental cross-section {sigma}({bar p}p {yields} ee* {yields} ee{gamma}) at the 95% confidence level in a contact-interaction model and a gauge-mediated interaction model. Limits are also presented as exclusion regions in the parameter space of the excited electron mass (M{sub e*}) and the compositeness energy scale ({Lambda}). In the contact-interaction model, for which there are no previously published limits, they find M{sub e*} < 906 GeV is excluded for M{sub e*} = {Lambda}. In the gauge-mediated model, the exclusion region in the M{sub e*} versus the phenomenological coupling f/{Lambda} parameter space is extended to M{sub e*} < 430 GeV for f/{Lambda} {approx} 10{sup -2} GeV{sup -1}. In comparison, other experiments have excluded M{sub e*} < 280 GeV for f/{Lambda} {approx} 10{sup -2} GeV{sup -1}.

Gerberich, Heather Kay; /Duke U.

2004-07-01

243

An Electron Fixed Target Experiment to Search for a New Vector Boson A' Decaying to e+e-  

Energy Technology Data Exchange (ETDEWEB)

We describe an experiment to search for a new vector boson A' with weak coupling {alpha}' {approx}> 6 x 10{sup -8} {alpha} to electrons ({alpha} = e{sup 2}/4{pi}) in the mass range 65 MeV < m{sub A'} < 550 MeV. New vector bosons with such small couplings arise naturally from a small kinetic mixing of the 'dark photon' A' with the photon - one of the very few ways in which new forces can couple to the Standard Model - and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiation off an electron beam, and could appear as narrow resonances with small production cross-section in the trident e{sup +}e{sup -} spectrum. We summarize the experimental approach described in a proposal submitted to Jefferson Laboratory's PAC35, PR-10-009. This experiment, the A' Experiment (APEX), uses the electron beam of the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory (CEBAF) at energies of {approx} 1-4 GeV incident on 0.5-10% radiation length Tungsten wire mesh targets, and measures the resulting e{sup +}e{sup -} pairs to search for the A' using the High Resolution Spectrometer and the septum magnet in Hall A. With a {approx} 1 month run, APEX will achieve very good sensitivity because the statistics of e{sup +}e{sup -} pairs will be {approx} 10,000 times larger in the explored mass range than any previous search for the A' boson. These statistics and the excellent mass resolution of the spectrometers allow sensitivity to {alpha}'/{alpha} one to three orders of magnitude below current limits, in a region of parameter space of great theoretical and phenomenological interest. Similar experiments could also be performed at other facilities, such as the Mainz Microtron.

Essig, Rouven; Schuster, Philip; /SLAC; Toro, Natalia; /Stanford U., Phys. Dept.; Wojtsekhowski, Bogdan; /Jefferson Lab

2010-06-11

244

Perspectives for indirect dark matter search with AMS-2 using cosmic-ray electrons and positrons  

Energy Technology Data Exchange (ETDEWEB)

The AMS-2 experiment will be launched with the Space Shuttle Discovery and installed on the International Space Station in 2010. It is designed to perform precision spectroscopy of many different cosmic-ray species including electrons and positrons. While the nature of dark matter is as yet unknown, dark matter annihilating in the Galactic halo is a well-motivated source of cosmic-ray electrons and positrons. The cosmic-ray positron fraction data available so far show significant deviations between different measurements and from the expectation for purely secondary production. The differences between the measurements up to particle energies of 6 GeV can be understood in a framework of charge-sign-dependent solar modulation and the spectra show excellent agreement if corrected for these time-dependent effects. Recent observations of an excess in the high-energy electron spectrum by ATIC might be connected to the excess in the positron fraction. A possible source of both signatures could be dark matter annihilation or a nearby pulsar. A measurement of the anisotropy of high-energy electrons could distinguish between both scenarios. Therefore the sky coverage of AMS-2 will be discussed in addition to possible dark matter scenarios and the sensitivity of the AMS-2 experiment to these effects.

Beischer, B; Von Doetinchem, P; Gast, H; Kirn, T; Schael, S [I. Physikalisches Institut, RWTH Aachen University, 52074 Aachen (Germany)], E-mail: Stefan.Schael@physik.rwth-aachen.de

2009-10-15

245

Search for electron decay mode e"- ? ? + ?_e with prototype of Borexino detector  

International Nuclear Information System (INIS)

The prototype of the Borexino detector Counting Test Facility, located in the Gran Sasso laboratory, has been used to obtain a bound on the stability of the electron. The new lower limit on the mean lifetime defined on 32.1 days of data set is ?(e"- ? ? + ?_e) ? 4.6 · 10"2"6 years (90 % C.L.)

2002-01-01

246

LHC collision event at CMS showing four high energy electrons (CMS Higgs search)  

CERN Document Server

11sec animation of a Higgs->ZZ->4e candidate in CMS. Real CMS proton-proton collision events in which 4 high energy electrons (orange lines and towers) are observed. The event shows characteristics expected from the decay of a Higgs boson but is also consistent with background Standard Model physics processes.

CMS Collaboration

2011-01-01

247

Performances of the electromagnetic calorimeter and search for new gauge bosons in the di-electron channel at the LHC  

International Nuclear Information System (INIS)

The Standard Model of particle physics has known a tremendous rise during the twentieth century. Built up, from the early thirties to the seventies, this theory describing elementary particles and their interactions (electromagnetic, weak, strong) has now been intensively tested by LEP and Tevatron colliders. Besides its success, some problems remain and have lead to new theories attempting to go beyond the standard model. Many of them are predicting the existence of a new gauge boson Z', which is supposed to be observed at the TeV scale. Data recorded by the LHC since autumn 2008 are a new opportunity to check the consistency of the Standard Model and to search for new physics evidence. The work that has been done by the ATLAS collaboration during the last four years has focused on understanding detector's behaviour and analysing the very first collected collisions. This thesis is reflecting these two aspects. Therefore, the first part of this thesis describes the characterisation of a pathology of ATLAS liquid argon calorimeter electronics and of coherent noise bursts that have both been observed since the beginning of ATLAS operation. The policy deployed to preserve data quality is also detailed. The second part is focusing on the search for new Z' gauge boson. In case this particle was to exist, its decay into an electron and a positron would lead to a new massive resonance in the dielectron invariant mass spectrum. Therefore electron reconstruction and identification performances are closely looked at, especially at high transverse momentum. Analysis made on the 4.9 fb-1 of collected data is reported. As no significant excess with respect to Standard Model predictions is observed, the dielectron invariant mass spectrum is interpreted to derive mass limits concerning the existence of new Z' gauge bosons appearing in grand unification theories (E6) and effective sequential standard model (SSM). These limits and those derived by the CMS collaboration are the best ever set on such new bosons. (author)

2012-01-01

248

Search for muon-neutrino to electron-neutrino transitions in MINOS.  

Science.gov (United States)

This Letter reports on a search for nu(mu) --> nu(e) transitions by the MINOS experiment based on a 3.14x10(20) protons-on-target exposure in the Fermilab NuMI beam. We observe 35 events in the Far Detector with a background of 27+/-5(stat)+/-2(syst) events predicted by the measurements in the Near Detector. If interpreted in terms of nu(mu) --> nu(e) oscillations, this 1.5sigma excess of events is consistent with sin2(2theta(13)) comparable to the CHOOZ limit when |Delta m2|=2.43x10(-3) eV2 and sin2(2theta(23))=1.0 are assumed. PMID:20366304

Adamson, P; Andreopoulos, C; Arms, K E; Armstrong, R; Auty, D J; Ayres, D S; Backhouse, C; Barnes, P D; Barr, G; Barrett, W L; Becker, B R; Belias, A; Bernstein, R H; Betancourt, M; Bhattacharya, D; Bishai, M; Blake, A; Bock, G J; Boehm, J; Boehnlein, D J; Bogert, D; Bower, C; Cavanaugh, S; Chapman, J D; Cherdack, D; Childress, S; Choudhary, B C; Cobb, J H; Coelho, J A B; Coleman, S J; Cronin-Hennessy, D; Culling, A J; Danko, I Z; de Jong, J K; Devenish, N E; Diwan, M V; Dorman, M; Erwin, A R; Escobar, C O; Evans, J J; Falk, E; Feldman, G J; Frohne, M V; Gallagher, H R; Godley, A; Goodman, M C; Gouffon, P; Gran, R; Grashorn, E W; Grzelak, K; Habig, A; Harris, D; Harris, P G; Hartnell, J; Hatcher, R; Heller, K; Himmel, A; Holin, A; Howcroft, C; Huang, X; Hylen, J; Irwin, G M; Isvan, Z; Jaffe, D E; James, C; Jensen, D; Kafka, T; Kasahara, S M S; Koizumi, G; Kopp, S; Kordosky, M; Koskinen, D J; Krahn, Z; Kreymer, A; Lang, K; Ling, J; Litchfield, P J; Litchfield, R P; Loiacono, L; Lucas, P; Ma, J; Mann, W A; Marshak, M L; Marshall, J S; Mayer, N; McGowan, A M; Mehdiyev, R; Meier, J R; Messier, M D; Metelko, C J; Michael, D G; Miller, W H; Mishra, S R; Mitchell, J; Moore, C D; Morfín, J; Mualem, L; Mufson, S; Musser, J; Naples, D; Nelson, J K; Newman, H B; Nichol, R J; Nicholls, T C; Ochoa-Ricoux, J P; Oliver, W P; Ospanov, R; Paley, J; Para, A; Patterson, R B; Patzak, T; Pavlovi?, Z; Pawloski, G; Pearce, G F; Petyt, D A; Pittam, R; Plunkett, R K; Rahaman, A; Rameika, R A; Raufer, T M; Rebel, B; Reichenbacher, J; Rodrigues, P A; Rosenfeld, C; Rubin, H A; Ryabov, V A; Sanchez, M C; Saoulidou, N; Schneps, J; Schreiner, P; Shanahan, P; Smart, W; Smith, C; Sousa, A; Speakman, B; Stamoulis, P; Strait, M; Tagg, N; Talaga, R L; Thomas, J; Thomson, M A; Thron, J L; Tinti, G; Toner, R; Tsarev, V A; Tzanakos, G; Urheim, J; Vahle, P; Viren, B; Ward, D R; Watabe, M; Weber, A; Webb, R C; West, N; White, C; Whitehead, L; Wojcicki, S G; Wright, D M; Yang, T; Zhang, K; Zheng, H; Zois, M; Zwaska, R

2009-12-31

249

Search for muon-neutrino to electron-neutrino transitions in MINOS.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This Letter reports on a search for nu(mu) --> nu(e) transitions by the MINOS experiment based on a 3.14x10(20) protons-on-target exposure in the Fermilab NuMI beam. We observe 35 events in the Far Detector with a background of 27+/-5(stat)+/-2(syst) events predicted by the measurements in the Near Detector. If interpreted in terms of nu(mu) --> nu(e) oscillations, this 1.5sigma excess of events is consistent with sin2(2theta(13)) comparable to the CHOOZ limit when |Delta m2|=2.43x10(-3) eV2 ...

Adamson, P.; Andreopoulos, C.; Arms, Ke; Armstrong, R.; Auty, Dj; Ayres, Ds; Backhouse, C.; Barnes, Pd; Barr, G.; Barrett, Wl; Becker, Br; Belias, A.; Bernstein, Rh; Betancourt, M.; Bhattacharya, D.

2009-01-01

250

Improved search for Muon-neutrino to electron-neutrino oscillations in MINOS.  

Science.gov (United States)

We report the results of a search for ?(e) appearance in a ?(?) beam in the MINOS long-baseline neutrino experiment. With an improved analysis and an increased exposure of 8.2 × 10(20) protons on the NuMI target at Fermilab, we find that 2 sin(2) (?(23))sin(2)(2?(13))<0.12(0.20) at 90% confidence level for ? = 0 and the normal (inverted) neutrino mass hierarchy, with a best-fit of 2sin(2) (?(23))sin(2)(2?(13)) = 0.041(-0.031)(+0.047) (0.079(-0.053) (+0.071)). The ?(13) = 0 hypothesis is disfavored by the MINOS data at the 89% confidence level. PMID:22107623

Adamson, P; Auty, D J; Ayres, D S; Backhouse, C; Barr, G; Betancourt, M; Bishai, M; Blake, A; Bock, G J; Boehnlein, D J; Bogert, D; Cao, S V; Cavanaugh, S; Cherdack, D; Childress, S; Coelho, J A B; Corwin, L; Cronin-Hennessy, D; Danko, I Z; de Jong, J K; Devenish, N E; Diwan, M V; Dorman, M; Escobar, C O; Evans, J J; Falk, E; Feldman, G J; Frohne, M V; Gallagher, H R; Gomes, R A; Goodman, M C; Gouffon, P; Graf, N; Gran, R; Grzelak, K; Habig, A; Hartnell, J; Hatcher, R; Himmel, A; Holin, A; Huang, X; Hylen, J; Irwin, G M; Isvan, Z; Jaffe, D E; James, C; Jensen, D; Kafka, T; Kasahara, S M S; Koizumi, G; Kopp, S; Kordosky, M; Kreymer, A; Lang, K; Lefeuvre, G; Ling, J; Litchfield, P J; Loiacono, L; Lucas, P; Mann, W A; Marshak, M L; Mathis, M; Mayer, N; McGowan, A M; Mehdiyev, R; Meier, J R; Messier, M D; Michael, D G; Miller, W H; Mishra, S R; Mitchell, J; Moore, C D; Mualem, L; Mufson, S; Musser, J; Naples, D; Nelson, J K; Newman, H B; Nichol, R J; Nowak, J A; Ochoa-Ricoux, J P; Oliver, W P; Orchanian, M; Paley, J; Patterson, R B; Pawloski, G; Pearce, G F; Phan-Budd, S; Plunkett, R K; Qiu, X; Ratchford, J; Rebel, B; Rosenfeld, C; Rubin, H A; Sanchez, M C; Schneps, J; Schreckenberger, A; Schreiner, P; Shanahan, P; Sharma, R; Sousa, A; Tagg, N; Talaga, R L; Thomas, J; Thomson, M A; Toner, R; Torretta, D; Tzanakos, G; Urheim, J; Vahle, P; Viren, B; Walding, J J; Weber, A; Webb, R C; White, C; Whitehead, L; Wojcicki, S G; Yang, T; Zwaska, R

2011-10-28

251

Improved Search for Muon-Neutrino to Electron-Neutrino Oscillations in MINOS  

Energy Technology Data Exchange (ETDEWEB)

We report the results of a search for {nu}{sub e} appearance in a {nu}{sub {mu}} beam in the MINOS long-baseline neutrino experiment. With an improved analysis and an increased exposure of 8.2 x 10{sup 20} protons on the NuMI target at Fermilab, we find that 2sin{sup 2}({theta}{sub 23})sin{sup 2}(2{theta}{sub 13}) < 0.12(0.20) at 90% confidence level for {delta} = 0 and the normal (inverted) neutrino mass hierarchy, with a best-fit of 2sin{sup 2}({theta}{sub 23})sin{sub 2}(2{theta}{sub 13}) = 0.041{sub -0.031}{sup +0.047}(0.079{sub -0.053}{sup +0.071}). The {theta}{sub 13} = 0 hypothesis is disfavored by the MINOS data at the 89% confidence level.

Bishai M.; Diwan, M.V..; Jaffe, D.E.; Ling, J.; Viren, B.; Whitehead, L.

2011-10-28

252

Search for Electron Antineutrino Appearance at the ?m2˜1eV2 Scale  

Science.gov (United States)

The MiniBooNE Collaboration reports initial results from a search for ?¯???¯e oscillations. A signal-blind analysis was performed using a data sample corresponding to 3.39×1020 protons on target. The data are consistent with background prediction across the full range of neutrino energy reconstructed assuming quasielastic scattering, 200

Aguilar-Arevalo, A. A.; Anderson, C. E.; Brice, S. J.; Brown, B. C.; Bugel, L.; Conrad, J. M.; Djurcic, Z.; Fleming, B. T.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Gonzales, J.; Grange, J.; Green, C.; Green, J. A.; Imlay, R.; Johnson, R. A.; Karagiorgi, G.; Katori, T.; Kobilarcik, T.; Linden, S. K.; Louis, W. C.; Mahn, K. B. M.; Marsh, W.; Mauger, C.; McGary, V. T.; Metcalf, W.; Mills, G. B.; Moore, C. D.; Mousseau, J.; Nelson, R. H.; Nienaber, P.; Nowak, J. A.; Osmanov, B.; Pavlovic, Z.; Perevalov, D.; Polly, C. C.; Ray, H.; Roe, B. P.; Russell, A. D.; Shaevitz, M. H.; Sorel, M.; Spitz, J.; Stancu, I.; Stefanski, R. J.; Tayloe, R.; Tzanov, M.; van de Water, R. G.; Wascko, M. O.; White, D. H.; Wilking, M. J.; Zeller, G. P.; Zimmerman, E. D.

2009-09-01

253

Search for Electron Antineutrino Appearance at the ?m2?1 eV2 Scale  

International Nuclear Information System (INIS)

The MiniBooNE Collaboration reports initial results from a search for ????e oscillations. A signal-blind analysis was performed using a data sample corresponding to 3.39x1020 protons on target. The data are consistent with background prediction across the full range of neutrino energy reconstructed assuming quasielastic scattering, 200?QE<3000 MeV: 144 electronlike events have been observed in this energy range, compared to an expectation of 139.2±17.6 events. No significant excess of events has been observed, both at low energy, 200-475 MeV, and at high energy, 475-1250 MeV. The data are inconclusive with respect to antineutrino oscillations suggested by data from the Liquid Scintillator Neutrino Detector at Los Alamos National Laboratory.

2009-09-11

254

Search for electron antineutrino appearance at the deltam(2) approximately 1 eV(2) Scale.  

Science.gov (United States)

The MiniBooNE Collaboration reports initial results from a search for nu(mu)-->nu(e) oscillations. A signal-blind analysis was performed using a data sample corresponding to 3.39x10(20) protons on target. The data are consistent with background prediction across the full range of neutrino energy reconstructed assuming quasielastic scattering, 200

Aguilar-Arevalo, A A; Anderson, C E; Brice, S J; Brown, B C; Bugel, L; Conrad, J M; Djurcic, Z; Fleming, B T; Ford, R; Garcia, F G; Garvey, G T; Gonzales, J; Grange, J; Green, C; Green, J A; Imlay, R; Johnson, R A; Karagiorgi, G; Katori, T; Kobilarcik, T; Linden, S K; Louis, W C; Mahn, K B M; Marsh, W; Mauger, C; McGary, V T; Metcalf, W; Mills, G B; Moore, C D; Mousseau, J; Nelson, R H; Nienaber, P; Nowak, J A; Osmanov, B; Pavlovic, Z; Perevalov, D; Polly, C C; Ray, H; Roe, B P; Russell, A D; Shaevitz, M H; Sorel, M; Spitz, J; Stancu, I; Stefanski, R J; Tayloe, R; Tzanov, M; Van de Water, R G; Wascko, M O; White, D H; Wilking, M J; Zeller, G P; Zimmerman, E D

2009-09-11

255

Search for Scalar Leptoquark Pairs Decaying to Electrons and Jets in pp Collisions  

International Nuclear Information System (INIS)

We have searched for the pair production of first generation scalar leptoquarks in the eejj channel using the full data set (123 pb-1) collected with the D0 detector at the Fermilab Tevatron during 1992 endash 1996. We observe no candidates with an expected background of approximately 0.4 events. Comparing the experimental 95% confidence level upper limit to theoretical calculations of the cross section with the assumption of a 100% branching fraction of eq, we set a lower limit on the mass of a first generation scalar leptoquark of 225 GeV/c2. The results of this analysis rule out the interpretation of the excess of high Q2 events at DESY HERA as leptoquarks which decay exclusively to eq. copyright 1997 The American Physical Society

1997-12-01

256

Search for the Neutron Electric Dipole Moment at the SNS at Oak Ridge  

International Nuclear Information System (INIS)

The possible existence of a non-zero electric dipole moment (EDM) of the neutron is of fundamental interest for our understanding of the nature of electro-weak and strong interactions. The experimental search for this moment has the potential to reveal new sources of T and CP violation and to challenge calculations that propose extensions to the Standard Model. A new experiment being developed at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory seeks to lower the current EDM limit of the neutron by a factor of 50 to 100 over the present upper limit of 2.9x10-26 e cm.

2010-02-10

257

Electric dipole moment searches: Effect of linear electric field frequency shifts induced in confined gases, II  

CERN Document Server

The next generation of particle edm searches will be at such a high sensitivity that it will be possible for the results to be contaminated by a systematic error resulting from the interaction of the motional (E x v/c) magnetic field with stray field gradients. In this paper we extend previous work to present an analytic form for the frequency shift in the case of a rectangular storage vessel and discuss the implications of the result for the neutron edm experiment which will be installed at the SNS (Spallation Neutron Source) by the LANL collaboration

Golub, R

2008-01-01

258

Development of francium atomic beam for the search of the electron electric dipole moment  

Directory of Open Access Journals (Sweden)

Full Text Available For the measurement of the electron electric dipole moment using Fr atoms, a Fr ion-atom conversion is one of the most critical process. An ion-atom converter based on the “orthotropic” type of Fr source has been developed. This converter is able to convert a few keV Fr ion beam to a thermal atomic beam using a cycle of the surface ionization and neutralization. In this article, the development of the converter is reported.

Sato Tomoya

2014-03-01

259

Development of francium atomic beam for the search of the electron electric dipole moment  

Science.gov (United States)

For the measurement of the electron electric dipole moment using Fr atoms, a Fr ion-atom conversion is one of the most critical process. An ion-atom converter based on the "orthotropic" type of Fr source has been developed. This converter is able to convert a few keV Fr ion beam to a thermal atomic beam using a cycle of the surface ionization and neutralization. In this article, the development of the converter is reported.

Sato, Tomoya; Ando, S.; Aoki, T.; Arikawa, H.; Ezure, S.; Harada, K.; Hayamizu, T.; Inoue, T.; Ishikawa, T.; Itoh, M.; Kato, K.; Kato, T.; Kawamura, H.; Nataraj, H. S.; Uchiyama, A.; Aoki, T.; Furukawa, T.; Hatakeyama, A.; Hatanaka, K.; Imai, K.; Murakami, T.; Shimizu, Y.; Wakasa, T.; Yoshida, H. P.; Sakemi, Y.

2014-03-01

260

On the keV sterile neutrino search in electron capture  

CERN Multimedia

A joint effort of cryogenic microcalorimetry (CM) and high-precision Penning-trap mass spectrometry (PT-MS) in investigating atomic orbital electron capture (EC) can shed light on the possible existence of heavy sterile neutrinos with masses from 0.5 to 100 keV. Sterile neutrinos are expected to perturb the shape of the atomic de-excitation spectrum measured by CM after a capture of the atomic orbital electrons by a nucleus. This effect should be observable in the ratios of the capture probabilities from different orbits. The sensitivity of the ratio values to the contribution of sterile neutrinos strongly depends on how accurately the mass difference between the parent and the daughter nuclides of EC-transitions can be measured by, e.g., PT-MS. A comparison of such probability ratios in different isotopes of a certain chemical element allows one to exclude many systematic uncertainties and thus could make feasible a determination of the contribution of sterile neutrinos on a level below 1%. Several electron ...

Filianin, P E; Eliseev, S A; Gastaldo, L; Novikov, Yu N; Shabaev, V M; Tupitsyn, I I; Vergados, J

2014-01-01

 
 
 
 
261

Electron measurements and search for Higgs bosons in multi-lepton channels with the CMS experiment at LHC  

International Nuclear Information System (INIS)

This thesis presents three years of work with the CMS experiment, in the context of the first LHC collisions. Electron objects were studied in particular, as major tools for multi-lepton analyses, in particular the H ? ZZ(*) ? 4l analysis. During the first months of collisions, we took part in the validation of data registered by the electromagnetic calorimeter. We also measured the efficiency of the level-1 electron and photon trigger during the whole 2010 year. The plateau efficiency is of 99.6% (resp. 98.5 %) on electrons in the barrel part (resp. in the end cap part) of the calorimeter. In order to optimize the discovery potential, we built a new electron charge measurement algorithm. In CMS, this measurement is affected by the large amount of material present in the inner tracker. The performance of this algorithm was measured on 2010 data, for electrons from Z boson decay passing a standard selection. The probability of charge mis-identification is of 1.06% (0.19% with a specific selection), in agreement with the simulation. The physics analysis that was built during this PhD searches doubly charged Higgs bosons decaying into lepton pairs. For the amount of data registered in 2010, one background event is expected to pass the selection, while the amount of signal events depends on the mass hypothesis and on the model. One event was found on data, in agreement with the background expectation, hence the signal was excluded on larger mass ranges than previous experiments: a mass limit was set between 122 GeV/c2 and 176 GeV/c2, depending on the model. (author)

2011-01-01

262

Avaliação da Geração de Microtrincas do Aço Rápido ABNT M2 no Processo EDM com Adição de SiC - DOI: 10.4025/actascitechnol.v30i2.543 Evaluation of the Microcrack Generation of ABNT M2 High Speed Steel in EDM Process With Addition of Silicon Carbide Powder - DOI: 10.4025/actascitechnol.v30i2.543  

Directory of Open Access Journals (Sweden)

Full Text Available É sabido que a Usinagem por Descargas Elétricas (EDM, é um processo térmico onde pode-se ter temperaturas muito elevadas (superiores a 1200 °C na região de usinagem. Conseqüentemente é fácil de entender o fato das peças usinadas por EDM, apresentarem camadas superficiais endurecidas, refundidas e com elevado números de microtrincas superfíciais. A formação de microtrincas está associada com o desenvolvimento de altas tensões térmicas que excedem a tensão máxima de resistência do material. Além disso as microtrincas superficiais penetram em profundidade com extensões que dependem da energia de descarga. O trabalho proposto, tem por objetivo estudar o efeito da adição de pó de SiC em vários fluidos dielétricos, sobre a geração de microtrincas superficiais, no aço rápido ABNT M2, durante a usinagem por descargas elétricas. Os resultados apresentados mostram uma redução da quantidade de microtrincas nas superfícies usinadas, quando se adiciona pó de SiC ao dielétrico, quando comparadas com as usinadas com EDM convencional.It is known that Electrical Discharge Machining (EDM, it is a thermal process where it can be had very high temperatures (higter than 1200° C in the region of machining consequently is easy to understand that during each electric discharge, hight temperatures are generated, causing local fusion or even evaporation of the material machined. In each discharge, a crater is formed in the material and a small crater is formed in the electrode. Of every melted material produced in each discharge, only 15%, or minus, it is removed through the dielectric liquid. The remaining of the melted material solidifies forming a wrinkled surface. The characteristics of the surface obtained, overlap of craters, globules of sullage, “chimneys ", bubbles (formed when the gases arrested are liberated through the material resolidificado, they are revealed through an analysis by scanning electron microscope. O proposed work, has for objective to study the effect of the addition of powder of SiC in several dielectric fluids, on microcrack generation, in workpiece of the high speed steel (ABNT M2, during the electrical discharge machining. The presented results show that the samples machined with the addition of powders of SiC presented significant reduction of the number of microcrack in the surface machined, when compared with the machined with conventional EDM.

José Roberto Pereira Rodrigues

2008-10-01

263

Search for cosmic ray electron-positron anisotropies with the Pamela data  

International Nuclear Information System (INIS)

Using data taken by the Pamela experiment during 5 years of operation we studied the anisotropy in the arrival direction of cosmic ray electrons and positrons with energy above 40 GeV. We report on a study of anisotropy in the e± flux at different angular scales extending from 30° up to 90°, furthermore a directional analysis has been performed around the Sun direction. The observed distribution of arrival directions is consistent with the isotropic expectation at any angular scale used in this study and no significant evidence of strong anisotropies has been observed, also the analysis around the Sun direction did not show any significant excess.

2013-02-01

264

Search for electron screening of nuclear reactions at sub-Coulomb energies  

International Nuclear Information System (INIS)

The reaction 3He(d, p)4He has been investigated for E = 6 t 42 keV with the use of D projectiles and 3He atomic gas target nuclides as well as with 3He projectiles and D2 molecular gas target nuclides. These studies show for the first time the predicted effects of electron screening on low-energy fusion cross sections, i.e. a nearly exponential enhancement of the cross sections compared to the case of bare nuclei. The enhancement is about a factor of 2 smaller for the case d(3He, p)4He due to the molecular nature of the D2 target nuclides. The reactions 6Li(p, ?)3He and 7Li(p, ?)4He have also been studied for E = 10 to 65 keV with the use of solid LiF targets. The results also indicate an exponential enhancement due to the effects of electron screening. (orig.)

1989-04-01

265

Low Energy Electron and Nuclear Recoil Thresholds in the DRIFT-II Negative Ion TPC for Dark Matter Searches  

CERN Document Server

Understanding the ability to measure and discriminate particle events at the lowest possible energy is an essential requirement in developing new experiments to search for weakly interacting massive particle (WIMP) dark matter. In this paper we detail an assessment of the potential sensitivity below 10 keV in the 1 m^3 DRIFT-II directionally sensitive, low pressure, negative ion time projection chamber (NITPC), based on event-by-event track reconstruction and calorimetry in the multiwire proportional chamber (MWPC) readout. By application of a digital smoothing polynomial it is shown that the detector is sensitive to sulfur and carbon recoils down to 3.5 and 2.2 keV respectively, and 1.2 keV for electron induced tracks. The energy sensitivity is demonstrated through the 5.9 keV gamma spectrum of 55Fe, where the energy resolution is sufficient to identify the escape peak. In addition to recoil direction reconstruction for WIMP searches this sensitivity suggests new prospects for applications also in KK axion s...

Burgos, S; Forbes, J; Ghag, C; Gold, M; Hagemann, C; Kudryavtsev, V A; Lawson, T B; Loomba, D; Majewski, P; Muna, D; Murphy, A St J; Paling, S M; Petkov, A; Plank, S J S; Robinson, M; Sanghi, N; Snowden-Ifft, D P; Spooner, N J C; Turk, J; Tziaferi, E

2009-01-01

266

Second User Acceptance Test of the Electronic Document Management System at the Defense Finance and Accounting Service Operating Location Omaha, Nebraska.  

Science.gov (United States)

The overall evaluation objective was to determine whether the Electronic Document Management (EDM) system can satisfactorily execute vendor payment workflows while providing adequate security for system and production data. Specifically, we determined whe...

1997-01-01

267

A combined muon-neutrino and electron-neutrino oscillation search at MiniBooNE  

Energy Technology Data Exchange (ETDEWEB)

MiniBooNE seeks to corroborate or refute the unconfirmed oscillation result from the LSND experiment. If correct, the result implies that a new kind of massive neutrino, with no weak interactions, participates in neutrino oscillations. MiniBooNE searches for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations with the Fermi National Accelerator Laboratory 8 GeV beam line, which produces a {nu}{sub {mu}} beam with an average energy of {approx} 0.8 GeV and an intrinsic {nu}{sub e} content of 0.4%. The neutrino detector is a 6.1 m radius sphere filled with CH{sub 2}, viewed by 1540 photo-multiplier tubes, and located 541 m downstream from the source. This work focuses on the estimation of systematic errors associated with the neutrino flux and neutrino interaction cross section predictions, and in particular, on constraining these uncertainties using in-situ MiniBooNE {nu}{sub {mu}} charged current quasielastic (CCQE) scattering data. A data set with {approx} 100,000 events is identified, with 91% CCQE purity. This data set is used to measure several parameters of the CCQE cross section: the axial mass, the Fermi momentum, the binding energy, and the functional dependence of the axial form factor on four-momentum transfer squared. Constraints on the {nu}{sub {mu}} and {nu}{sub e} fluxes are derived using the {nu}{sub {mu}} CCQE data set. A Monte Carlo study of a combined {nu}{sub {mu}} disappearance and {nu}{sub e} appearance oscillation fit is presented, which improves the {nu}{sub {mu}} {yields} {nu}{sub e} oscillation sensitivity of MiniBooNE with respect to a {nu}{sub e} appearance-only fit by 1.2-1.5{sigma}, depending on the value of {Delta}m{sup 2}.

Monroe, Jocelyn R.; /Columbia U.

2006-07-01

268

High-speed micro electrode tool fabrication by a twin-wire EDM system  

International Nuclear Information System (INIS)

This paper describes a new machining process which combines twin-electro-wire together with two electro discharge circuits to rapidly fabricate micro electrode tools. The results show that transistor electro discharge and RC electro discharge circuits coexist to fabricate micro tools with rough and finish machining both on the same machine. Compared to conventional wire electro discharge grinding (WEDG) technology, a twin-wire EDM system that combines rough and finish machining into one process allows the efficient fabrication of micro tools. This high-speed micro tool fabrication process can be applied not only to micro electrode machining but also to micro punching tool and micro probing tips machining

2008-10-01

269

Development of assessment method for NPP organizations using organizational factors : SPOOM and EDM based  

Energy Technology Data Exchange (ETDEWEB)

Organizational factors have been known as an important contributor to plant safety. Previous studies associated with organization factors mainly deals with the aspect of safety of an organization. For an organization, however, effectiveness or the aspect of economy related with work activities is also important. This paper introduces a conceptual model, SPOOM and EDM (Self Poly-Oriented Organization Model and Evaluation Diamond Model), for evaluating an organization with respect to both safety and economy. It also shows how the proposed model can be applied for the evaluation of an NPP organization through the analysis of real event.

Kim, S. H.; Kim, Y. I.; Lee, Y. S.; Kim, C. S.; Jung, C. H. [Seoul National University, Seoul (Korea, Republic of); Kim, J. H. [KAERI, Taejon (Korea, Republic of)

2003-07-01

270

Relationship of Surface Roughness with Current and Voltage During Wire EDM  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Wire EDM is in use for a long time for cutting punches and dies, shaped pockets and other machine parts. Surface finish of the machined surface mainly depends on current and voltage used during machining. In the present research experimental investigations have been conducted to establish relationships of job surface finish with current and voltage. Brass wires of diameters 0.3, 0.25, 0.20 and 0.15 mm were used. Work materials tested were mild steel, aluminum, cemented carbide, copper and sta...

Ahsan Ali Khan; Munira Bt. Mohd Ali; Norhashimah Bt. Mohd Shaffiar

2006-01-01

271

Improving the efficiency of the emissions and dispersion modeling system (EDMS) Version 3.1  

Energy Technology Data Exchange (ETDEWEB)

As a follow-up to last year's technical review of Version 3.0, this paper presents a more detailed analysis of the inefficiencies of the modeling system. Current shortcomings with EDMS 3.1, primarily the ease of entering input data, the computational time needed, and the disk storage space needed, will be shown. The importance of each topic will be conveyed. Examples of each will be given, and recommendations for the improvement of the model will be presented.

Tino, V.R.

1999-07-01

272

Searches for Permanent Electric Dipole Moments - Some Recent Developments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Searches for permanent electric dipole moments (EDMs) of fundamental particles render the possibility to discover New Physics beyond present Standard Theory. New ideas for experiments have come up recently which may allow to lower present limits substantially or even find unambiguous effects. Such are predicted by a variety of speculative models. The identification of potential sources for CP and T-violation will require to study several systems, which all have different sen...

Jungmann, Klaus P.

2005-01-01

273

Radiation degradation behavior of chlorine-containing vinyl copolymers. Search for improved electron-beam resists  

International Nuclear Information System (INIS)

Vinyl copolymers with high radiation degradation sensitivity have been synthesized by copolymerizing vinylidene chloride (VDC), CH"2 = CCl"2, with methyl methacrylate (MMA), methacrylonitrile, methyl ?-chloroacrylate, and dimethyl itaconate using emulsion techniques. In addition, copolymers of methyl ?-chloroacrylate with methyl methacrylate and poly(?-chloroacrylonitrile) were studied. Introduction of vinylidene chloride into methyl methacrylate polymers caused a sharp increase in G/sub s/ even at relatively low VDC incorporation. Upon 29% VDC incorporation, the G/sub s/ value increased from 1.3 (homopolymer of MMA) to 3.4. G/sub s/ was found to be a linear function of copolymer content for several systems, but G/sub x/ was not. At higher VDC levels, the increase in G/sub s/ was countered by increases in G/sub x/. At lower VDC levels, G/sub x/ was suppressed below the values predicted by a linear G/sub x/ dependence on composition for such systems as VDC/MMA, MCA/MMA, and ?-chloroacrylonitrile/MMA. The VDC/MMA copolymer (29% VDC) gave a sensitivity of 4.0 x 10"-_5 C/cm_2 to electron beam exposure using the 0% unexposed resist thickness loss criterion and is 2 to 3 times more sensitive than PMMA. Poly(?-chloroacrylonitrile) is a negative resist with a sensitivity of 5 x 10"-_5 C/cm_2 using one-micron line images for testing

1980-01-01

274

Electric dipole moments of dyon and 'electron'  

International Nuclear Information System (INIS)

The electric and magnetic dipole moments of dyon fermions are calculated within N=2 supersymmetric Yang-Mills theory including the ?-term. It is found, in particular, that the gyroelectric ratio deviates from the canonical value of 2 for the monopole fermion (nm=1, ne=0) in the case ??0. Then, applying the S-duality transformation to the result for the dyon fermions, we obtain an explicit prediction for the electric dipole moment (EDM) of the charged fermion ('electron'). It is thus seen that the approach presented here provides a novel method for computing the EDM induced by the ?-term. (author)

2007-11-01

275

Electric Dipole Moments of Dyon and `Electron'  

Science.gov (United States)

The electric and magnetic dipole moments of dyon fermions are calculated within N = 2 supersymmetric Yang-Mills theory including the ?-term. It is found, in particular, that the gyroelectric ratio deviates from the canonical value of 2 for the monopole fermion (n_{m} = 1, n_{e} = 0) in the case ? ? 0. Then, applying the S-duality transformation to the result for the dyon fermions, we obtain an explicit prediction for the electric dipole moment (EDM) of the charged fermion (`electron'). It is thus seen that the approach presented here provides a novel method for computing the EDM induced by the ?-term.

Kobayashi, M.; Kugo, T.; Tokunaga, T.

2007-11-01

276

Fabrication of high-density micro holes by upward batch micro EDM  

International Nuclear Information System (INIS)

A large number of micro holes are needed for biomedical parts, ink-jet nozzles and micro droplet spraying parts. In this study, an inexpensive machining approach for producing a batch of micro holes is proposed. A set of previously introduced w-EDM mechanisms is employed to horizontally cut the batch micro electrodes precisely. Through the process arrangement, the micro electrodes and workpiece are not unloaded, repositioned and re-corrected until all the tasks are completed. The micro workpiece is clamped onto the specially designed jig and moved above the micro electrodes to perform machining of the mass micro holes by upward batch micro EDM. The entire procedure is carried out on a developed multifunctional tabletop CNC machine tool. An array of 400 through holes of the identical sizes is successfully fabricated on a stainless-steel plate with a thickness of 30 µm by using the modified peck-drilling method. Experimental results confirmed that the proposed approach could accelerate the removal of debris, reduce the occurrence of abnormal discharges and decrease the machining time

2008-08-01

277

Fabrication of high-density micro holes by upward batch micro EDM  

Science.gov (United States)

A large number of micro holes are needed for biomedical parts, ink-jet nozzles and micro droplet spraying parts. In this study, an inexpensive machining approach for producing a batch of micro holes is proposed. A set of previously introduced w-EDM mechanisms is employed to horizontally cut the batch micro electrodes precisely. Through the process arrangement, the micro electrodes and workpiece are not unloaded, repositioned and re-corrected until all the tasks are completed. The micro workpiece is clamped onto the specially designed jig and moved above the micro electrodes to perform machining of the mass micro holes by upward batch micro EDM. The entire procedure is carried out on a developed multifunctional tabletop CNC machine tool. An array of 400 through holes of the identical sizes is successfully fabricated on a stainless-steel plate with a thickness of 30 µm by using the modified peck-drilling method. Experimental results confirmed that the proposed approach could accelerate the removal of debris, reduce the occurrence of abnormal discharges and decrease the machining time.

Chen, Shun-Tong

2008-08-01

278

Status report on the nEDM project at the Paul Scherrer Institut, Switzerland  

Energy Technology Data Exchange (ETDEWEB)

A non-zero neutron electric dipole moment (nEDM) would violate time reversal and parity symmetry. Its detection would be a major discovery, but already improving the present upper limit of 2.9.10{sup -26} e.cm will further constrain theories beyond the Standard Model of particle physics, such as supersymmetry. The goal of the nEDM collaboration is to improve the current sensitivity by almost two orders of magnitude. This shall be achieved in two phases: Firstly by using an upgraded version of the former ILL-RAL-Sussex apparatus (oILL) at the new powerful ultracold neutron source at PSI. This source is expected to deliver neutron densities increased by a factor {approx}100 compared to the former location at ILL. Secondly a new spectrometer is being designed and developed in order to improve statistical sensitivity and enhance control over systematic effects. After moving the oILL spectrometer to Paul Scherrer Institut in 2009, numerous test measurements have been performed. The apparatus has been characterized in great detail and many new features have been installed. It is now ready for first measurements with ultracold neutrons. This talk presents the current achievements with focus on the alterations and improvements that have been implemented.

Franke, Beatrice [Paul Scherrer Institut, Villigen (Switzerland); Exzellenzcluster Universe, Muenchen (Germany); Collaboration: Neutron EDM-Collaboration

2011-07-01

279

Study of the Effects of Edm Notch Width on Eddy Current Signal Response  

Science.gov (United States)

A sometimes stated rule of thumb is that the eddy current signal from a fatigue crack can be 60% of the strength produced by a similarly sized, rectangular EDM notch. A study was conducted to explore the effect that the width of a discontinuity has on signal strength when inspecting low conductivity materials for small cracks with eddy current surface probes. EDM notches of different sizes and shapes were planted in Ti-6246 and IN-100 specimens. Each of the two materials received six 0.020 inch long by 0.010 inch deep notches and six 0.030 inch and 0.015 inch deep notches. Three of the notches of each size were rectangular shaped and three were semicircular shaped. One of the notches in each material size group was 0.005 inch wide, one was 0.003 inch wide and one was 0.001 inch wide. Each of the notches was scanned using absolute and differential pencil probes driven at several different frequencies. The experimental results were compared with numerically generated results, which allowed for a zero width notch to be considered. The results indicated that the signal reduction factor from a 0.005 inch wide, rectangular notch to a theoretical zero-width notch of the same size ranged from 25 to 42%.

Nakagawa, N.; Yang, M.; Larson, B. F.; Madison, E. M.; Raulerson, D.

2009-03-01

280

Investigating effects of process variables on MRR in EDM by using Taguchi parameter design approach  

Directory of Open Access Journals (Sweden)

Full Text Available The correct selection of manufacturing conditions is one of the most important aspects to take into consideration in the majority of manufacturing processes and, particularly, in processes related to Electrical Discharge Machining (EDM. It is a capable of machining geometrically complex or hard material components, that are precise and difficult-to-machine such as heat treated tool steels, composites, super alloys, ceramics, carbides, heat resistant steels etc. being widely used in die and mold making industries, aerospace, aeronautics and nuclear industries. OHNS-EN-31 is a high car bon alloy steel which achieves high degree of hardness with compressive strength and abrasive resistance. OHNS-EN-31 steel, which is popularly used in automotive type applications, like axle, bearings, spindle and molding dies etc. In this paper we have tried to investigate effect of machining parameter such as discharge current, pulse on time, and pulse of time on MRR in EDM while machining OHNS-EN-31 STEEL using Cu tool . A well-designed experimental scheme was used to reduce the total number of experiments. Parts of the experiment were conducted with the L18 orthogonal array based on the Taguchi method. The results of analysis of variance (ANOVA indicate that the proposed mathematical model can be adequately describe the performance within the limit of factors being studied. The optimal set of process parameters has also been predicted to maximize the MRR.

Amit Joshi

2012-08-01

 
 
 
 
281

Optimization of EDM Characteristics of WC/5ni Composites Using Response Surface Methodology  

Directory of Open Access Journals (Sweden)

Full Text Available Electric discharge machining (EDM has achieved remarkable success in the manufacture of conductive ceramic materials for the modern metal industry. The mathematical models are proposed for the modeling and analysis of the effects of machining parameters on the performance characteristics in the EDM process of WC/5Ni, Which is produced through powder metallurgy route. Response surface methodology (RSMis used to explain the influences of four machining parameters ; tool rotational speed(S, discharge current(C, pulse-on time(T and flushing pressure(P on the performance characteristics of the material removal rate (MRR, and surface roughness (Ra. The experiment plan adopts the central composite design (CCD. The separable influence of individual machining parameters and the interaction between these parameters are also investigated by using analysis of variance (ANOVA. This study highlights that the proposed mathematical models have proven to fit and predict values of performance characteristics close to those readings recorded experimentally with a 95% confidence interval. Results shows that are the two significant factors affecting material removal rate (MRR are discharge current and flushing pressure. The discharge current, flushing pressure and electrode rotation have statistical significance on the surface roughness (Ra.

V. Chandrasekaran

2013-11-01

282

Extension of traceable calibration for electronic distance measuring instruments beyond the length of the laboratory  

Science.gov (United States)

Electronic distance measuring instruments (EDMs) are devices used by surveyors where calibrated tape measures are not adequate or appropriate. Modern EDMs are generally accurate and reliable, are commonly capable of measuring up to 6 km, and may be combined with an electronic theodolite in a total station unit. Precise traceable calibration of EDMs is possible using a linear displacement interferometer, for example, with the respective reflectors in back-to-back configuration. Calibration data may be analysed for scale error and cyclical error. The distances so calibrated are usually constrained by the length of laboratory (and/or straight rails) available, as well as by the maximum working distance of the interferometer, but may be extended further with caution by the introduction of mirrors to fold the EDM beam. This paper describes the apparatus used to calibrate an EDM up to 200 m in a 60 m laboratory, and investigates some of the problems and artefacts that can arise, for example, from unwanted intermediate reflections of the EDM beam.

Forde, Lucy C.; Howick, Eleanor F.

2003-11-01

283

An estimate of the uncertainty due to counting statistics in a novel type of neutron EDM experiment  

Energy Technology Data Exchange (ETDEWEB)

A novel type of EDM experiment using ultracold neutrons produced in a superthermal source, coupled with the dressed neutron technique has been proposed. Here an estimate is made of the uncertainty in the electric dipole moment of neutron that would arise from neutron counting statistics in such an experiment

Thompson, D. (Rutherford Appleton Lab., Chilton (United Kingdom))

1992-03-01

284

A lower bound on hadronic EDMs from CP violation in D0-D¯ mixing in SUSY alignment models  

Science.gov (United States)

The SM predictions for CP violating effects in D meson systems are highly suppressed at the per mill level. Therefore, any experimental evidence for a sizable CP violation in D-D mixing would unambiguously point towards a New Physics (NP) signal. Within supersymmetric scenarios, the popular alignment models can naturally account for large, non-standard effects in D-D mixing. We demonstrate that, within alignment models, detectable CP violating effects in D-D mixing would unambiguously imply a lower bound for the electric dipole moment (EDM) of hadronic systems, like the neutron EDM and the mercury EDM, in the reach of future experimental sensitivities. The simultaneous evidence of CP violation in D meson systems together with non-vanishing hadronic EDMs would strongly support the idea of SUSY alignment models and disfavour gauge-mediated SUSY breaking models, SUSY models with MFV and non-Abelian SUSY flavour models. As a byproduct of our analysis, we study the correlation between the time dependent CP asymmetry in decays to CP eigenstates S and the semileptonic asymmetry a both model independently and in SUSY alignment models.

Altmannshofer, Wolfgang; Buras, Andrzej J.; Paradisi, Paride

2010-05-01

285

A Lower Bound on hadronic EDMs from CP Violation in D0-D0bar mixing in SUSY Alignment Models  

CERN Document Server

The SM predictions for CP violating effects in D meson systems are highly suppressed at the per mill level. Therefore, any experimental evidence for a sizable CP violation in D0-D0bar mixing would unambiguously point towards a New Physics (NP) signal. Within supersymmetric scenarios, the popular alignment models can naturally account for large, non-standard effects in D0-D0bar mixing. We demonstrate that, within alignment models, detectable CP violating effects in D0-D0bar mixing would unambiguously imply a lower bound for the electric dipole moment (EDM) of hadronic systems, like the neutron EDM and the mercury EDM, in the reach of future experimental sensitivities. The simultaneous evidence of CP violation in D meson systems together with non vanishing hadronic EDMs would strongly support the idea of SUSY alignment models and disfavour gauge-mediated SUSY breaking models, SUSY models with MFV and non-Abelian SUSY flavour models. As a byproduct of our analysis, we study the correlation between the time depen...

Altmannshofer, Wolfgang; Paradisi, Paride

2010-01-01

286

Searches for massive neutrino emission in {sup 14}C beta and {sup 55}Fe electron-capture decays  

Energy Technology Data Exchange (ETDEWEB)

In 1985 Simpson reported evidence for the emission of a 17 keV mass neutrino in a small fraction of tritium beta decays. An experimental controversy ensued in which a number of both positive and negative results were reported. The beta spectrum of {sup 14}C was collected in a unique {sup 14}C-doped planar germanium detector and a distortion was observed that initially confirmed Simpson`s result. Further tests linked this distortion to a splitting of the collected charge between the central detector and the surrounding guard ring in a fraction of the events. A second {sup 14}C measurement showed no evidence for emission of a 17 keV mass neutrino. In a related experiment, a high statistics electron-capture internal-bremsstrahlung photon spectrum of {sup 55}Fe was collected with a coaxial germanium detector. A local search for departures from a smooth shape near the endpoint was performed, using a second-derivative technique. An upper limit of 0.65% (95% C.L.) for the mixing Of a neutrino in the mass range 5--25 keV was established. The upper limit on the mixing of a 17 keV mass neutrino was 0.14% (95% C.L.).

Wietfeldt, F.E. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

1994-05-01

287

Search for positron trapping at quantum-dot like Cu nano particles on the surface of Fe using positron annihilation induced Auger electron spectroscopy (PAES)  

International Nuclear Information System (INIS)

This paper presents preliminary results of a search for evidence of trapping of positrons at quantum-dot like particles of Cu at the surface of Fe using positron annihilation induced Auger electron spectroscopy. In PAES energetic electron emission results from Auger transitions initiated by annihilation of core electrons with positrons trapped in an image-potential well at the surface. The further localization of positrons at Cu aggregates at the Fe surface should be signaled by a sharp enhancement of the Cu PAES intensities. Preliminary studies of PAES intensities as a function of the surface concentration of Cu at an Fe alloy surface provide evidence for such an enhancement. (orig.)

2004-01-01

288

Laser-driven optically-pumped Cs magnetometer array for a nEDM experiment  

International Nuclear Information System (INIS)

The Standard Model of Particle Physics predicts a static electric dipole moment for the neutron (nEDM) breaking time reversal and parity symmetry. This prediction is several orders of magnitude below the current best experimental limit dn -26 ecm (90 % CL). We are currently setting up a new experiment at the new ultra-cold neutron (UCN) source at the Paul Scherrer Institut, Switzerland, with the ultimate goal to improve the sensitivity limit by almost two orders of magnitude. Besides passive and active compensation of external magnetic fields we will use an array of laser-driven optically-pumped atomic cesium magnetometers to control and monitor the stability and homogeneity of the magnetic field at the neutron precession chamber. A first array of eight cesium magnetometers was used to obtain the field distribution and stability over the neutron precession volume on a sub-pT level. The setup and first results are presented.

2010-03-15

289

TECHNICAL NOTE: Fabrication of microelectrodes for EDM machining by a combined etching process  

Science.gov (United States)

In this note, multi-headed microelectrodes were machined by a combined sequence process of WEDG, ultrasonic-aided chemical etching and an electrochemical anodic etching procedure. Electrodes were cut to 0.1 mm by a wire EDM machine from an original diameter of 3 mm in the first step. Electrodes were continually machined by chemical etching and anodic electrochemical etching. During electrolysis, copper impurity produced on the anode is not easily removed from its matrix. A ultrasonic mechanism was utilized to agitate the ferric chloride solution to clean the surface impurity off the electrode. The performance of ultrasonic-aided chemical etching was also studied. Micro single electrodes and foil electrodes were processed by chemical etching. Multi-headed microelectrodes can be machined to 30 µm by the combined sequence etching technology proposed.

Weng, Feng-Tsai

2004-05-01

290

Simultaneous Processing Method for Micro-Rods and Holes Using EDM  

Science.gov (United States)

This paper describes a new method for micro-EDM drilling which utilizes the wear of rod electrodes. With this method, a pair of micro rod and micro hole can be machined in a single process, while with conventional methods, the micro rod electrode needs to be formed before machining the micro hole. Processing conditions were optimized for the new method to obtain higher aspect ratio for the micro rods. Results of experiments also showed the following: 1) This method can be applied to AISI1045, AISI304 and Kovar and any electrode diameter size. 2) From the second process, if machining many holes using the same electrode, the electrode shape can be regenerated with excellent repeatability and holes processed efficiently. 3) The influence of carbon adhering to the tip region of the rod electrode is large, which is why the rod electrode becomes needle sharp.

Yamazaki, Minoru; Mori, Noritosi; Suzuki, Takemi; Kunieda, Masanori

291

CryoEDM: a cryogenic experiment to measure the neutron Electric Dipole Moment  

International Nuclear Information System (INIS)

We have constructed an instrument, CryoEDM, to measure the neutron electric dipole moment to a precision of 10-28 e cm at the Institut Laue-Langevin. The main characteristic is that it is operating entirely in a cryogenic environment, at temperatures of 0.7 K within superfluid helium. Ultracold neutrons are produced in a superthermal source and stored within the superfluid in a storage cell which is held in a magnetic and electric field. NMR measurements are carried out to look for any shifts in the neutron Larmor precession frequency associated with the electric field and the neutrons are detected in-situ in the superfluid. Low temperature SQUID magnetometry is used to monitor the magnetic field. We report on the current status of the project that is now being commissioned and give an outlook on the future exploitation of the instrument.

2010-11-01

292

Higgs Mediated EDMs in the Next-to-MSSM: An Application to Electroweak Baryogenesis  

CERN Multimedia

We perform a study on the predictions of electric-dipole moments (EDMs) of neutron, Mercury (Hg), Thallium (Tl), deuteron, and Radium (Ra) in the framework of next-to-minimal supersymmetric standard model (NMSSM) with CP-violating parameters in the superpotential and soft-supersymmetry-breaking sector. We confine to the case in which only the physical tree-level CP phase $(\\phi'_\\lambda - \\phi'_\\kappa)$, associated with the couplings of the singlet terms in the superpotential and with the vacuum-expectation-values (VEVs), takes on a nonzero value. We found that the one-loop contributions from neutralinos are mostly small while the two-loop Higgs-mediated contributions of the Barr-Zee (BZ) type diagrams dominate. We emphasize a scenario motivated by electroweak baryogenesis.

Cheung, Kingman; Lee, Jae Sik; Senaha, Eibun

2011-01-01

293

Integrated management systems and workflow-based electronic document management: An empirical study  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: Many global organizations have aligned their strategy and operation via the ISO-based framework of integrated management system (IMS that allows them to merge quality, environment, health and safety management systems. In such context, having a robust electronic document management system (EDMS is essential, especially at global enterprises where a large amount of documents generated by processes flows through different work cultures. However, there is no "one-size-fits-all" design for EDMS because it depends on organizations' needs, size and resource allocation. This article discusses the interrelation between EDMS and IMS in order to suggest a best practice. Design/methodology/approach: This article methodologically based upon a qualitative, interpretivistic, longitudinal empirical study in a wind turbine factory. Findings and Originality/value: IMS improvement and effectiveness has been overlooking EDMS as a key factor in establishing appropriate technological support of the IMS processes. Rightful application of EDMS can further contribute to organizational learning, precision of documentation and cross-organisational collaboration. Research limitations/implications: Theorising on IMS needs a stronger perspective of the technological limitations and potentials of basing IMS on EDMS. Practical implications: IMS are complex systems involving a large number of administrative functions. EDMS provides a formal representation with automation potentials both heightening and securing document trustworthiness. Social implications: IMS has a tendency to stay with professionals, e.g. line managers and QA/QC/QMS professionals. The EDMS line of discussion suggests a broader inclusion. Originality/value: Researching IMS as a technological implementation is giving a better platform of aligning the IMS with other business processes and is bringing IMS closer to the operational activities within the enterprise.

Hang Thu Pho

2014-01-01

294

A mathematical model to choose effective cutting parameters in electroerosion, EDM  

Directory of Open Access Journals (Sweden)

Full Text Available urpose: Machining by electroerosion is a process of removal of material by fusion, vaporization and erosion, reserved essentially for conductor and semiconductor materials. It can be used to machine metals and alloys, the tempered steels, different type of ceramic alloys, other metallic carbides and even for harder materials such as polycrystalline diamond etc. The aim of this paper is to develop a mathematical model for the effect of cutting parameters on the machining by electro discharge machining used widely in industrial applications.Design/methodology/approach: It is about a study and detail analyzes effect of the cutting conditions in machining by electroerosion of steel 42CD4-42CrMo4 on the surface quality of the parts. The statistical method of the analysis of variance “ANOVA” makes it possible to release the considerable effects of the parameters of cut on the criteria of performance of machining by electroerosion, EDM.Findings: The result of the study shows that the nature of the electrode used and the different grades of the materials machined by Electro Discharge Machining, EDM, influence considerably the volume of the removal of material and the surface quality of the produced parts. However, more the resistivity of the electrode increases, more relative wear of the electrode will be important and more the volume of removal of material decreases.Research limitations/implications: This study needs more experimental results for evaluation of the cutting parameters in detail and introduce in the model developed here.Practical implications: This model developed based on the experimental study gives very simple choice of cutting parameters depending on the materials.Originality/value: A very simple model has been develop here after a comprehensive study and this model contains an experimental design, and application ANOVA analysis as a function of experimental results and allows to obtain a smooth surface and high quality machined pieces and can decrease at cost price of the pieces in the manufacturing engineering.

A. Medfai

2011-07-01

295

Search for excited electrons and muons in \\sqrt {s}=8 TeV proton-proton collisions with the ATLAS detector  

Science.gov (United States)

The ATLAS detector at the Large Hadron Collider is used to search for excited electrons and excited muons in the channel pp ? ??* ? ???, assuming that excited leptons are produced via contact interactions. The analysis is based on 13 fb-1 of pp collisions at a centre-of-mass energy of 8 TeV. No evidence for excited leptons is found, and a limit is set at the 95% credibility level on the cross section times branching ratio as a function of the excited-lepton mass m?*. For m?* ? 0.8 TeV, the respective upper limits on ?B(?* ? ??) are 0.75 and 0.90 fb for the e* and ?* searches. Limits on ?B are converted into lower bounds on the compositeness scale ?. In the special case where ? = m?*, excited-electron and excited-muon masses below 2.2 TeV are excluded.

Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Adomeit, S.; Adye, T.; Aefsky, S.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmad, A.; Ahmadov, F.; Ahsan, M.; Aielli, G.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alam, M. A.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alonso, F.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Ammosov, V. V.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Arfaoui, S.; Arguin, J.-F.; Argyropoulos, S.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Astbury, A.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, D.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, S.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartsch, V.; Bassalat, A.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beale, S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belloni, A.; Beloborodova, O. L.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernard, C.; Bernat, P.; Bernhard, R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertolucci, F.; Besana, M. I.; Besjes, G. J.; Bessidskaia, O.; Besson, N.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Bittner, B.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blocki, J.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boek, T. T.; Boelaert, N.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bolnet, N. M.; Bomben, M.; Bona, M.; Boonekamp, M.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Branchini, P.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Brendlinger, K.; Brenner, R.; Bressler, S.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Broggi, F.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brost, E.; Brown, G.; Brown, J.

2013-09-01

296

Energies, transition rates, and electron electric dipole moment enhancement factors for Ce IV and Pr V  

CERN Document Server

Energies, transition rates, and electron electric dipole moment (EDM) enhancement factors are calculated for low-lying states of Ce IV and Pr V using relativistic many-body perturbation theory. This study is related to recent investigations of the more complicated Gd IV ion, which is promising for electron EDM experiments. The ions Ce IV and Pr V both have a single valence electron, permitting one to carry out reliable ab-initio calculations of energy levels, transition rates and other atomic properties using well developed computational methods.

Savukov, I M; Safronova, U I; Safronova, M S

2003-01-01

297

Performance of Silver Coated Copper Tool with Kerosene-servotherm Dielectric in EDM of Monel 400TM  

Directory of Open Access Journals (Sweden)

Full Text Available Technologies to improve the material removal rate and reduce the tool removal rate, achieve the good surface finish and dimensional accuracy are very demanding in electrical discharge machining (EDM. The work focused on comparing performance of optimum silver coated copper tool electrode with conventionally used copper tool electrode using optimum proportionate kerosene-servotherm and commercial grade EDM oil in electrical discharge machining of Monel 400TM. The optimum thickness of silver coating over the copper tool electrode and optimum proportionate Kerosene-Servotherm dielectric were developed experimentally. The copper tool electrode with silver coating of five microns reported slightly more material removal rate, very low tool wear rate, better dimensional accuracy and good surface finish than copper tool electrode with Kerosene-Servotherm (75:25 dielectric.

Joel Daniel

2012-01-01

298

Optimization by Grey Relational Analysis of EDM Parameters in Machining Al-15% SiC MMC Using Multihole Electrode  

Directory of Open Access Journals (Sweden)

Full Text Available In this study the optimization of the Electrical Discharge Machining (EDM process with multiple performance characteristics based on orthogonal array with the Grey relational analysis was studied. The Grey relational analysis theory was used to resolve the complicated interrelationships among the multiple performance characteristics. In the present study, attempt was made to find the optimal machining conditions under which a blind-hole can be drilled using a multihole electrode. The Taguchi method was used to determine the relations between machining parameters and process characteristics. In this study, the machining parameters, namely electrode polarity, discharge current, pulse on time, pulse off time and dielectric pressure were optimized with considerations of multiple performance characteristics including machining time, electrode wear and surface roughness. Experimental results showed that machining performance in the EDM process can be improved effectively through this approach.

K. Balamurugan

2012-01-01

299

Microgravity Electron Electric Dipole Moment Experiment with a Cold Atom Beam  

Science.gov (United States)

New physics beyond the Standard Model: The small CP violation contained in the Standard Model is insufficient to account for the baryon/antibaryon asymmetry in the universe. New sources of CP violation are provided by extensions to the Standard Model. They contain CP-violating phases that couple directly to leptons and from which a large electron electric dipole moment (EDM) may be generated. Observation of an electron EDM would be proof of a Standard Model extension because the Standard Model only allows an electron EDM of less than 10(exppp -57) C-m (S.I. units; 1 C-m = 1.6 x 10(exp -21) e-cm). A null result, however, constrains models and improving the limit tightens constraints, further restricting the models.

Gould, Harvey

2003-01-01

300

Optimization by Grey Relational Analysis of EDM Parameters in Machining Al-15% SiC MMC Using Multihole Electrode  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study the optimization of the Electrical Discharge Machining (EDM) process with multiple performance characteristics based on orthogonal array with the Grey relational analysis was studied. The Grey relational analysis theory was used to resolve the complicated interrelationships among the multiple performance characteristics. In the present study, attempt was made to find the optimal machining conditions under which a blind-hole can be drilled using a multihole electrode. The T...

Murugesan, S.; Balamurugan, K.

2012-01-01

 
 
 
 
301

Predictive Modelling & Analysis of AISI 1045 Tool Steel in Die Sinking E.D.M. using Neural Network Approach  

Directory of Open Access Journals (Sweden)

Full Text Available Electrical Discharge Machining (EDM is a non conventional machining process, where electrically conductive materials are machined by using a precisely controlled spark that occurs between an electrode and a work piece in the presence of a dielectric fluid. It has been a demanding research area to model and optimize the EDM process in the present scenario. In this work a neural network model is presented for predictions of material removal rate (MRR & tool wear rate (TWR in die sinking electrical discharge machining (EDM process for American Iron and Steel Institute 1045 tool steel with copper electrode.Experimentation has been carried out on EDM of AISI 1045 tool Steel. The experimental results have been used to train ANN using Back-Propagation Algorithm which gives the optimum value of the performance parameters like Material Removal Rate (MRR and Tool Wear Rate (TWR based on the influence of various electrode materials and processing parameters such as Gap Voltage, Peak Current, Pulse on time and Pulse off time. According to the correlation coefficients diagram it was concluded that the ANN tool gives us the best possible predictions for the data we have trained.Also we are getting ANN MRR results very much closer to our experimental MRR values.This shows the values that are very much possible to correlate amongst one another apart from taking experiments and finally the values of experimental TWR and predicted TWR are nearly correlating with one another.This shows that the ANN can be trained enough to give us close results by predicting the values.

Samaddar Prasenjeet 1 , B. B. Patel 2 , K. B. Rathod

2013-08-01

302

Electronic search strategies to identify reports of cluster randomized trials in MEDLINE: low precision will improve with adherence to reporting standards  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Cluster randomized trials (CRTs present unique methodological and ethical challenges. Researchers conducting systematic reviews of CRTs (e.g., addressing methodological or ethical issues require efficient electronic search strategies (filters or hedges to identify trials in electronic databases such as MEDLINE. According to the CONSORT statement extension to CRTs, the clustered design should be clearly identified in titles or abstracts; however, variability in terminology may make electronic identification challenging. Our objectives were to (a evaluate sensitivity ("recall" and precision of a well-known electronic search strategy ("randomized controlled trial" as publication type with respect to identifying CRTs, (b evaluate the feasibility of new search strategies targeted specifically at CRTs, and (c determine whether CRTs are appropriately identified in titles or abstracts of reports and whether there has been improvement over time. Methods We manually examined a wide range of health journals to identify a gold standard set of CRTs. Search strategies were evaluated against the gold standard set, as well as an independent set of CRTs included in previous systematic reviews. Results The existing strategy (randomized controlled trial.pt is sensitive (93.8% for identifying CRTs, but has relatively low precision (9%, number needed to read 11; the number needed to read can be halved to 5 (precision 18.4% by combining with cluster design-related terms using the Boolean operator AND; combining with the Boolean operator OR maximizes sensitivity (99.4% but would require 28.6 citations read to identify one CRT. Only about 50% of CRTs are clearly identified as cluster randomized in titles or abstracts; approximately 25% can be identified based on the reported units of randomization but are not amenable to electronic searching; the remaining 25% cannot be identified except through manual inspection of the full-text article. The proportion of trials clearly identified has increased from 28% between the years 2000-2003, to 60% between 2004-2007 (absolute increase 32%, 95% CI 17 to 47%. Conclusions CRTs should include the phrase "cluster randomized trial" in titles or abstracts; this will facilitate more accurate indexing of the publication type by reviewers at the National Library of Medicine, and efficient textword retrieval of the subset employing cluster randomization.

Grimshaw Jeremy M

2010-02-01

303

Fabrication of a micro-spherical tool in EDM combined with Ni-diamond co-deposition  

International Nuclear Information System (INIS)

This paper demonstrates a novel fabrication process using electro-discharge-machining (EDM) combined with co-deposited Ni-diamond composites to build a unique micro-spherical diamond tool. A micro tool is made by a hybrid process including wire electro-discharge grinding, EDM spherical forming, electrochemical machining and co-deposition. Tungsten carbide material is used as the tool substrate. The influence of EDM spherical forming and co-deposition parameters on the tool geometry is presented. The experimental result shows a unique micro-spherical diamond tool can be successfully built with suitable spherical forming parameters that are a peak current of 3 A, pulse duration of 40 µs and spindle rotational speed of 0 rpm in the air, and in Ni-diamond co-deposition are a current density of 7 A dm?2, diamond particle size of 3 µm, diamond particle concentration of 10 g l?1 and rotational speed of 15 rpm. When using this method, the micro tool has a better geometric shape, uniform particle distribution and suitable particle adhesion quantity. The tool is tested to machine a mold provided with a micro-spherical cavity in a high nickel alloy

2008-04-01

304

Fabrication of a micro-spherical tool in EDM combined with Ni-diamond co-deposition  

Science.gov (United States)

This paper demonstrates a novel fabrication process using electro-discharge-machining (EDM) combined with co-deposited Ni-diamond composites to build a unique micro-spherical diamond tool. A micro tool is made by a hybrid process including wire electro-discharge grinding, EDM spherical forming, electrochemical machining and co-deposition. Tungsten carbide material is used as the tool substrate. The influence of EDM spherical forming and co-deposition parameters on the tool geometry is presented. The experimental result shows a unique micro-spherical diamond tool can be successfully built with suitable spherical forming parameters that are a peak current of 3 A, pulse duration of 40 µs and spindle rotational speed of 0 rpm in the air, and in Ni-diamond co-deposition are a current density of 7 A dm-2, diamond particle size of 3 µm, diamond particle concentration of 10 g l-1 and rotational speed of 15 rpm. When using this method, the micro tool has a better geometric shape, uniform particle distribution and suitable particle adhesion quantity. The tool is tested to machine a mold provided with a micro-spherical cavity in a high nickel alloy.

Hung, Jung-Chou; Lien, Shao-Chun; Lin, Jui-Kuan; Huang, Fuang-Yuan; Yan, Biing-Hwa

2008-04-01

305

Electrical discharge machining (EDM) of Inconel 718 by using copper electrode at higher peak current and pulse duration  

Science.gov (United States)

This experimental work is an attempt to investigate the performance of Copper electrode when EDM of Nickel Based Super Alloy, Inconel 718 is at higher peak current and pulse duration. Peak current, Ip and pulse duration (pulse on-time), ton are selected as the most important electrical pulse parameters. In addition, their influence on material removal rate (MRR), electrode wear rate (EWR), and surface roughness (Ra) are experimentally investigated. The ranges of 10 mm diameter of Copper electrode are used to EDM of Inconel 718. After the experiments, MRR, EWR, and Ra of the machined surfaces need to be measured in order to evaluate the performance of the EDM process. In order to obtain high MRR, higher peak current in range of 20A to 40A and pulse duration in range of 200?s to 400?s were used. Experimental results have shown that machining at a highest peak current used of 40A and the lowest pulse duration of 200?s used for the experiment yields the highest material removal rate (MRR) with value 34.94 mm3/min, whereas machining at a peak current of 20A and pulse duration of 400?s yields the lowest electrode wear rate (EWR) with value -0.0101 mm3/min. The lowest surface roughness (Ra) is 8.53 ?m achieved at a lowest peak current used of 20A and pulse duration of 200?s.

Ahmad, S.; Lajis, M. A.

2013-12-01

306

Optimization of Electrical and Non Electrical Factors in EDM for Machining Die Steel Using Copper Electrode by Adopting Taguchi Technique  

Directory of Open Access Journals (Sweden)

Full Text Available EDM machining is used for very hard and complex cutting of conducting materials with higher surface finish and close dimensions. EDM process parameters are affected by both electrical and non electrical parameters. In these paper cutting of hard material high carbon high chromium (HCHcr D3 steel is done on electro discharge machine with copper as cutting tool electrode. This paper presents a work on the performance parameter optimization for material removal rate (MRR and electrode wear rate (EWR. There are electrical and non electrical factors which influences MRR and EWR such as voltage ,current pulse on time , pulse off time , dielectric fluid material , flushing pressure, tool rotation etc. In theses paper both the electrical factors and non electrical factors has been focused which governs MRR, EWR and there optimization. Paper is based on Design of experiment and optimization of EDM process parameters .The technique used is Taguchi technique which is a statistical decision making tool helps in minimizing the number of experiments and the error associated with it. The research showed that the peak current has significant effect on material removal rate.

Ajeet Bergaley

2013-08-01

307

Search for excited and exotic electrons in the e? decay channel in p anti-p collisions at ?s = 1.96 Tev  

International Nuclear Information System (INIS)

We present a search for excited and exotic electrons (e*) decaying to an electron and a photon, both with high transverse momentum. We use 202 pb"-"1 of data collected in p(bar p) collisions at ?s = 1.96 TeV with the CDF II detector. No signal above standard model expectation is seen for associated ee* production. We discuss the e* sensitivity in the parameter space of the excited electron mass M_e_* and the compositeness energy scale ?. In the contact interaction model, we exclude 132 GeV/c"2 < M_e_* < 879 GeV/c"2 for ? = M_e_* at 95% confidence level (C.L.). In the gauge-mediated model, we exclude 126 GeV/c"2 < M_e_* < 430 GeV/c"2 at 95% C.L. for the phenomenological coupling f/? ? 10"-"2 GeV"-"1

2005-01-01

308

Failure analysis of the Ringhals unit 3 EDM surfaces removed from the RPV outlet nozzle to safe end weld  

International Nuclear Information System (INIS)

During the 2000 RFO (Re-Fueling Outage) In-Service Inspection of the nozzle to safe end weld of the Hot Leg Reactor Pressure Vessel Nozzles in Ringhals 3 and 4, axially oriented defects in the Alloy 182 weld metal were detected. In the case of Ringhals 3, the defects were initially considered as being embedded and thus left for future consideration, whereas the defects in Ringhals 4 were judged as being surface breaking and removed by EDM (Electro Discharge Machining). During the RFO 2001, the defects in Ringhals 3 were also removed by EDM without applying any surface treatment subsequent to the sampling. The cavities were inspected using a standard ET technique for manufacturing control before the plant was allowed to return to service. After one cycle of operation, the cavities resulting from the boat sampling were inspected by ET and UT techniques and indications of renewed, shallow cracking were identified. The indications were pre-dominantly axially oriented, of limited depth and with surface breaking lengths varying from 4 to 18 mm. To investigate the cause of this cracking, it was decided to remove a second series of small boat samples from the areas with indications, prior to implementation of a permanent repair. To minimize the impact on the RFO schedule and the material loss that would have resulted from EDM boat sample removal, mini samples were removed manually, using a small axial grinder. The sampling was performed after nozzle decontamination and used a dry nozzle access system that had been specifically developed for the nozzle repair. The sample removal was completed in approximately two hours and a total of three samples were shipped to the Studsvik hot cell laboratories for failure analysis. The failure analysis revealed a typical surface morphology, resulting from the EDM process and confirmed that numerous micro-fissures may result from the process if it is utilized without proper optimization and care. On one of the boat samples, surface areas with higher micro-fissure density as well as macroscopic defects, probably related to process irregularities that had occurred during the initial sampling, were observed. Investigation of cross sections on the boat samples showed that in some case the surface defects resulting from the EDM process had lead to re-initiation of PWSCC of the Alloy 182 nozzle to safe end weld. The different stages of the failure analysis, as well as the conclusions that could be drawn from the metallographic examinations are presented in this paper. (authors)

2006-09-18

309

Economic Decision Making Model for Geothermal Sludge Disposal alternatives (EDM-GSD): Version 1. 0  

Energy Technology Data Exchange (ETDEWEB)

The Economic Decision Making Model for Geothermal Sludge Disposal Alternatives-Version 1.0'' (EDM-GSD 1.0) is a microcomputer-based dynamic model developed to assist in determining the benefits and costs of various geothermal solid waste treatment procedures. It is intended for use by geothermal managers in dealing with geothermal waste and treatment process issues as a means to assist in overcoming the technical and economic barriers to expanded geothermal energy utilization. The model is based on a 50MW flash plant. However, it is designed to provide the user with sufficient flexibility when inputing data to analyze all types of geothermal plants. Default values for economic and technical parameters can be overridden by the user through the input of specific data. In addition, data can be changed for any year of an analysis to account for desired changes in input parameters such as costs and distance to disposal sites. The results of the model will allow the user to: Determine current geothermal plant disposal costs; Evaluate the cost-effectiveness of alternative treatment techniques; and Evaluate the economic effects of changes in disposal regulations.

1987-09-01

310

Optimization of control parameters for SR in EDM injection flushing type on stainless steel 304 workpiece  

International Nuclear Information System (INIS)

The operating control parameters of injection flushing type of electrical discharge machining process on stainless steel 304 workpiece with copper tools are being optimized according to its individual machining characteristic i.e. surface roughness (SR). Higher SR during EDM machining process results for poor surface integrity of the workpiece. Hence, the quality characteristic for SR is set to lower-the-better to achieve the optimum surface integrity. Taguchi method has been used for the construction, layout and analysis of the experiment for each of the machining characteristic for the SR. The use of Taguchi method in the experiment saves a lot of time and cost of machining the experiment samples. Therefore, an L18 Orthogonal array which was the fundamental component in the statistical design of experiments has been used to plan the experiments and Analysis of Variance (ANOVA) is used to determine the optimum machining parameters for this machining characteristic. The control parameters selected for this optimization experiments are polarity, pulse on duration, discharge current, discharge voltage, machining depth, machining diameter and dielectric liquid pressure. The result had shown that the lower the machining diameter, the lower will be the SR.

2012-09-18

311

Pengaruh Arc On dan Arc Off Time Terhadap Kekasaran Permukaan dan Laju Pembuangan Geram Hasil Pemesinan Sinking EDM  

Directory of Open Access Journals (Sweden)

Full Text Available Sinking type electro discharge machine (EDM is the nwst popular non conventional machining method in the current decade based on modern CNC controlled. Although the EDM process has been used for decades, it is still widely misunderstood by many in manufacturing. The EDM is used when the work piece material is too hard, or the shape or location of the detail cannot easily be conventionally machined e.g. high precision mold and die with high surface quality. The performance of this process can be indicated by productivity and quality of product to be machined. An experiment to study the effect of machining parameter on productivity and surface quality has been done by varying the most important parameter arc on and arc off time. For this experiment a Charme Pulse CD-50M type sinking EDM machine is used to perform the machining process of tool steel SKD 11 material (55- 65 HRC with an copper electrode and esso lector 40 of dielectric fluid that having a density of 6.8 gr / cm3 and 1320C burning temperature for jet side flushing. The constant parameters are current 8 Ampere, voltage 40 volt and depth of machining 0.5 mm. The experimental data is analyzed by statistically program and the result are empirical formulas of the average roughness Ra = 0.624. A0.4. B-0.01 and the metal removal rate MRR = 0.2. A0.25.B0.53%2C where A is arc on time and B is arc off time. Abstract in Bahasa Indonesia : Electrical Discharge Machine (EDM sinking merupakan salah satu proses permesinan non konvensional yang berbasis komputer sebagai pengendali utamanya. Dimana EDM shinking digunakan untuk membuat rongga cetakan yang memiliki kontur yang kompleks dan kepresisian yang tinggi. Salah satu produk yang sering dikerjakaan oleh mesin EDM adalah dies dan mould yang memiliki kekerasan yang tinggi. Peranan dies dan mould pada proses manufaktur seperti deep drawing, forging, pengecoran dan lain-lain sangatlah berpengaruh terutama pada kualitas ketepatan dimensi, kepresisian dan kekasaran permukaan dies. Untuk meningkatkan produktivitas dan kualitas hasil produk sesuai dengan yang diharapkan maka pengetahuan paramater selama proses permesinan EDM haruslah baik. Suatu eksperimen yang bertujuan untuk mempelajari pengaruh arc on time dan arc off time terhadap kekasaran permukaan produk dilakukan untuk mengetahui karakteristik mesin EDM sinking. Eksperimen akan dilakukan pada mesin EDM sinking jenis Charme Pulse CD-50M dan benda kerja plat baja SKD 11 dengan kekerasan 55 s/d 61 HRC yang sering digunakan sebagai bahan dies, elektrode yang digunakan tembaga dan fluida dielectric adalah esso lector 40 dengan density 6,8 gr/cm3 pada temperature burning 132oC. Dalam pengujian ini analisa statistiknya untuk variable bebas adalah arc on time, arc of time. Adapun varible terikat (repon adalah kekasaran permukaan dan MRR (metal removal rate. Parameter pengujian yang konstan adalah arus listrik 8 ampere, voltase 40 volt, kedalaman pemotongan 0.5 mm, metode jet/side flushing dan untuk parameter pengujian yang tidak konstan adalah pulse on time, pulse of time dan waktu eksekusi tiap titik. Data yang diperoleh dianalisa statistik dengan software Minitab untuk mendapatkan persamaan empiris hubungan antara arc time dan arc off time terhadap kekasaran permukaan. Hasil dari pengujian ini didapatkan bahwa untuk off time konstan dan on time yang semakin naik didapatkan nilai kekasaran permukaan semakin besar dan nilai MRR semakin naik, untuk untuk on time yang konstan serta off time yang semakin naik didapatkan nilai kekasaran permukaan yang relatif konstan dan harga MRR semakin turun. Adapaun persamaan empiris yang didapatkan pada software minitab adalah: - Kekasaran Permukaan (Ra = 0.624.A0.4.B-0.01 - Metal Removal Rate (MRR = 0.2. A0.25.B-0.53 dimana A (arc on time, B (arc off time Kata kunci : Arc on time, arc off time, kekasaran permukaan, metal removal rate (MRR, EDM Sinking.

Suhardjono Suhardjono

2004-01-01

312

Search for neutral leptons  

Energy Technology Data Exchange (ETDEWEB)

At present we know of three kinds of neutral leptons: the electron neutrino, the muon neutrino, and the tau neutrino. This paper reviews the search for additional neutral leptons. The method and significance of a search depends upon the model used for the neutral lepton being sought. Some models for the properties and decay modes of proposed neutral leptons are described. Past and present searches are reviewed. The limits obtained by some completed searches are given, and the methods of searches in progress are described. Future searches are discussed. 41 references.

Perl, M.L.

1984-12-01

313

Search for neutral leptons  

International Nuclear Information System (INIS)

At present we know of three kinds of neutral leptons: the electron neutrino, the muon neutrino, and the tau neutrino. This paper reviews the search for additional neutral leptons. The method and significance of a search depends upon the model used for the neutral lepton being sought. Some models for the properties and decay modes of proposed neutral leptons are described. Past and present searches are reviewed. The limits obtained by some completed searches are given, and the methods of searches in progress are described. Future searches are discussed. 41 references

1984-11-03

314

Design for a fountain of YbF molecules to measure the electron's electric dipole moment  

International Nuclear Information System (INIS)

We propose an experiment to measure the electric dipole moment (EDM) of the electron using ultracold YbF molecules. The molecules are produced as a thermal beam by a cryogenic buffer gas source, and brought to rest in an optical molasses that cools them to the Doppler limit or below. The molecular cloud is then thrown upward to form a fountain in which the EDM of the electron is measured. A non-zero result would be unambiguous proof of new elementary particle interactions, beyond the standard model. (paper)

2013-05-01

315

An ionization chamber for coincidence experiments in a search for double beta positron decay and electron positron conversion of 78Kr  

International Nuclear Information System (INIS)

A search for double positron decay and electron capture with positron emission in the transition 78Kr(0+gs)?78Se(0+gs) has been carried out by using a high pressure ionization chamber surrounded by a set of NaI detectors. Coincidences between the emitted positron(s) and the two (four) consequent annihilation gammas have been looked for as signature(s) of the process(es). The ionization chamber of krypton gas (enriched up to 94.08% in the 78 isotope) registers the positron energy, whereas the set of sodium iodide scintillators searches for the annihilation gamma rays. The features and performances of the experimental device are presented and the results obtained for the half-life limits of the processes investigated are reported. ((orig.))

1995-03-15

316

Electron events from the scattering with solar neutrinos in the search of keV scale sterile neutrino dark matter  

Science.gov (United States)

In a previous work, we showed that it is possible to detect keV scale sterile neutrino dark matter ?s in a ? decay experiment using radioactive sources such as T3 or Ru106. The signals of this dark matter candidate are monoenergetic electrons produced in the neutrino capture process ?s+ N'?N+e-. These electrons have energy greater than the maximum energy of the electrons produced in the associated decay process N'?N+e-+? ¯e. Hence, signal electron events are well beyond the end point of the ? decay spectrum and are not polluted by the ? decay process. Another possible background, which is a potential threat to the detection of ?s dark matter, is the electron event produced by the scattering of solar neutrinos with electrons in target matter. In this article, we study in detail this possible background and discuss its implications for the detection of keV scale sterile neutrino dark matter. In particular, bound state features of electrons in Ru atoms are considered with care in the scattering process when the kinetic energy of the final electron is the same order of magnitude of the binding energy.

Liao, Wei; Wu, Xiao-Hong; Zhou, Hang

2014-05-01

317

Search for WW and WZ Resonances Decaying to Electron, Missing ET, and Two Jets in pp? Collisions at ?s=1.96??TeV.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Using data from 2: 9 fb(-1) of integrated luminosity collected with the CDF II detector at the Tevatron, we search for resonances decaying into a pair of on-shell gauge bosons, WW or WZ, where one W decays into an electron and a neutrino, and the other boson decays into two jets. We observed no statistically significant excess above the expected standard model background, and we set cross section limits at 95% confidence level on G* (Randall-Sundrum graviton), Z', and W' bosons. By comparing ...

Aaltonen, T.; Cabrera, Susana; Cuenca Almenar, Cristo?bal; A?lvarez Gonza?lez, B.; Casal, Bruno; Cuevas, Javier; Go?mez, G.; Rodrigo, Teresa; Ruiz Jimeno, Alberto; Scodellaro, Luca; Vila, Iva?n; Vilar, Roci?o

2010-01-01

318

Search for High Energy Electrons from New Neutral Massive Gauge Boson Decay in the CMS Detector at the LHC Using Monte Carlo Simulation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The existence of new heavy neutral massive boson Z? is a feature of many extensions of Standard Model models as the two-Higgs-doublet model (2HDM), the Hidden Abelian Higgs Model (HAHM), Left-Right Symmetric Model (LRSM), Sequential Standard Model (SSM) and Baryon number minus Lepton number Model (B-L). In the present work we search for two high energy electrons produced from decaying

Mansour, H. M. M.; Nady Bakhet

2013-01-01

319

Search for a new heavy gauge boson W? with event signature electron+missing transverse energy in pp? collisions at ?s=1.96??TeV  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present a search for a new heavy charged vector boson W? decaying to an electron-neutrino pair in pp? collisions at a center-of-mass energy of 1.96 TeV. The data were collected with the CDF II detector and correspond to an integrated luminosity of 5.3??fb-1. No significant excess above the standard model expectation is observed and we set upper limits on ?·B(W??e?). Assuming standard model couplings to fermions and the neutrino from the W? boson decay to be light, we exclud...

Aaltonen, T.; A?lvarez Gonza?lez, B.; Casal, Bruno; Cuevas, Javier; Palencia, Enrique; Rodrigo, Teresa; Ruiz Jimeno, Alberto; Scodellaro, Luca; Vila, Iva?n; Vilar, Roci?o; Go?mez, G.

2011-01-01

320

Results of a search for double positron decay and electron-positron conversion of [sup 78]Kr  

Energy Technology Data Exchange (ETDEWEB)

The results of a search for the 2[beta][sup +] and K[beta][sup +] decay modes of [sup 78]Kr, in a coincidence experiment using a high pressure ionization chamber of enriched [sup 78]Kr inside an enceinte of sodium iodine scintillators, are presented. After 4434 hours of counting time, the half-life lower limits obtained are T[sub 1/2](K[beta][sup +])[sub 0[nu

Saenz, C. (Instituto de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain)); Garcia, E. (Instituto de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain)); Klimenko, A. (Institute for Nuclear Research (Russian Academy of Sciences) (Russian Federation)); Kuzminov, V. (Institute for Nuclear Research (Russian Academy of Sciences) (Russian Federation)); Metlinsky, N. (Institute for Nuclear Research (Russian Academy of Sciences) (Russian Federation)); Morales, A. (Instituto de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain)); Morales, J. (Instituto de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain)); Novikov, V. (Institute for Nuclear Research (Russian Academy of Sciences) (Russian Federation)); Nunez-Lagos, R. (Instituto de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain)); Ortiz de Solorzano, A. (Instituto de Fisica Nuclear y Altas Energias, Universidad d

1994-05-01

 
 
 
 
321

Electronics  

... Electronics Electronics, an international, peer-reviewed Open Access journal. Electronics Submit to Electronics Login Register MDPI Journals A-Z For Authors For Editors ...Computers Cosmetics Crystals Dentistry Journal Diagnostics Diseases Diversity Econometrics Economies Education Sciences Electronics Energies Entropy Environments Fibers Foods Forests Future Internet Galaxies Games Genes ...Project Report Reply Retraction Review Short Note Technical Note Special Issue Page Electronics Electronics Home About this journal Indexing & Abstracting Instructions for ... 1 (2012) Electronics — Editors Journal Contact Electronics Editorial Office MDPI AG, Klybeckstrasse 64, 4057 Basel, Switzerland E-Mail: electronics@mdpi.com ...

322

Preliminary searches for hadron jets and for large transverse momentum electrons at the SPS anti pp collider  

International Nuclear Information System (INIS)

We present a preliminary analysis of the UA2 data collected during the last Collider run (20 nb"-"1 integrated luminosity) with particular emphasis on large transverse momentum hadron jets and on electrons having the configuration expected from the decay of electroweak bosons. The data provide very strong evidence of two-jet dominance in events with large transverse energy in the central region. Four electron candidates have been observed with a transverse momentum in excess of 20 GeV/c, which are associated with no other large transverse energy production within the UA2 acceptance. While this result is in all respects consistent with a W -> e? hypothesis, more work is needed to ensure that the background is well understood and to further ascertain electron identification. No electron pair was detected with an invariant mass in excess of 40 GeV/c"2. (orig.)

1983-05-01

323

The behavior of graphite and copper electrodes on the finish die-sinking electrical discharge machining (EDM of AISI P20 tool steel  

Directory of Open Access Journals (Sweden)

Full Text Available The machining parameter settings installed at CNC EDM machines are developed under optimum process conditions. Standard workpiece and electrode materials are used traditionally by machine manufacturers to establish the EDM parameter settings. However, this is not the usual situation of the tooling industry, where many different grades of workpiece and tool electrode materials are used. Consequently, the customers are required to develop their own process parameters, which normally demand many experimental tests. According to the aforementioned argument an experimental investigation on the EDM of AISI P20 tool steel under finish machining has been carried out. The tests were performed with graphite and copper as tool electrodes. Important EDM electrical parameters that influence the process performance were investigated. The measured technological outputs were the material removal rate Vw, volumetric relative wear J and workpiece surface finish Ra . The main conclusions can be summarized as follows: the best results for material removal rate Vw were reached when EDM with negative graphite electrodes. Graphite and copper tools presented similar results of Vw for positive polarity. For graphite and copper tools the lowest values of volumetric relative wear were achieved for positive polarity. The best surface roughness Ra was obtained for copper electrodes under negative polarity.

Fred L. Amorim

2007-12-01

324

Sensitive Search for a Permanent Muon Electric Dipole Moment  

CERN Document Server

We are proposing a new method to carry out a dedicated search for a permanent electric dipole moment (EDM) of the muon with a sensitivity at a level of 10^{-24} e cm. The experimental design exploits the strong motional electric field sensed by relativistic particles in a magnetic storage ring. As a key feature, a novel technique has been invented in which the g-2 precession is compensated with radial electric field. This technique will benefit greatly when the intense muon sources advocated by the developers of the muon storage rings and the muon colliders become available.

Semertzidis, Y K; Danby, G T; Jackson, J W; Larsen, R; Lazarus, D M; Meng, W; Morse, W M; Ozben, C; Prigl, R; Carey, R M; Miller, J P; Rind, O; Roberts, B L; Sulak, Lawrence R; Balakin, V; Bazhan, A; Dudnikov, A; Khazin, B I; Sylvestrov, G; Orlov, Yu F; Jungmann, Klaus; Debevec, P T; Hertzog, D W; Onderwater, Gerco; Stephenson, E J; Cushman, P B; Kronkvist, I J; Farley, Francis J M

2000-01-01

325

Search for excited electrons and muons in $\\sqrt{s}$=8 TeV proton-proton collisions with the ATLAS detector  

CERN Document Server

The ATLAS detector at the LHC is used to search for excited electrons and excited muons in the channel $pp -> ll^* -> ll\\gamma$, assuming that excited leptons are produced via contact interactions. The analysis is based on 13 fb$^{-1}$ of pp collisions at a centre-of-mass energy of 8 TeV. No evidence for excited leptons is found, and a limit is set at the 95% credibility level on the cross section times branching ratio as a function of the excited-lepton mass $m_l^*$. For $m_l^*$ > 0.8 TeV, the respective upper limits on $\\sigma^*B(l^* -> l\\gamma)$ are 0.75 fb and 0.90 fb for the $e^*$ and $\\mu^*$ searches. Limits on $\\sigma^*B$ are converted into lower bounds on the compositeness scale Lambda. In the special case where $\\Lambda = m_l^*$, excited-electron and excited-muon masses below 2.2 TeV are excluded.

Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Aefsky, Scott; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmad, Ashfaq; Ahmadov, Faig; Ahsan, Mahsana; Aielli, Giulio; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Astbury, Alan; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernard, Clare; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia, Olga; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare

2013-01-01

326

Search for Electron Antineutrino Appearance at the Delta m2?1??eV[superscript 2] Scale  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The MiniBooNE Collaboration reports initial results from a search for ?[over-bar] mu-->?[over-bar] e oscillations. A signal-blind analysis was performed using a data sample corresponding to 3.39×10[superscript 20] protons on target. The data are consistent with background prediction across the full range of neutrino energy reconstructed assuming quasielastic scattering, 200

Mcgary, Thanh; Katori, Teppei; Karagiorgi, Georgia Stelios; Conrad, Janet

2009-01-01

327

Search for High Energy Electrons from New Neutral Massive Gauge Boson Decay in the CMS Detector at the LHC Using Monte Carlo Simulation  

Directory of Open Access Journals (Sweden)

Full Text Available The existence of new heavy neutral massive boson Z? is a feature of many extensions of Standard Model models as the two-Higgs-doublet model (2HDM, the Hidden Abelian Higgs Model (HAHM, Left-Right Symmetric Model (LRSM, Sequential Standard Model (SSM and Baryon number minus Lepton number Model (B-L. In the present work we search for two high energy electrons produced from decayingheavy neutral massive boson in the events produced in proton-proton collisions at LHC and can be detected by CMS detector. We used the data which is produced from proton-proton collisions by Monte Carlo events generator for different energies at LHC, then we use the angular distribution, invariant mass, combined transverse momentum and combined rapidity distributions for the two high energy electrons produced from decay channel to detect thesignal. B-L extension of the SM model predicts the existence of aheavy neutral massive boson at high energies. From our results which we had simulated using MC programs forin the B-L extension of standard model, we predict a possible existence of new gaugeat LHC in the mass range 1 TeV to 1.5 TeV via electrons identification of the two high energy electrons by CMS detector.

Nady Bakhet

2013-05-01

328

Comment on "Search for new particles decaying into electron pairs of mass below 100 MeV/c^2"  

CERN Document Server

A re-analysis of data from electron-pair production following 160 A GeV 207Pb bombardment of nuclear emulsions indicates the production and decay of neutral particles of significantly lower invariant mass and shorter lifetimes than previously claimed (J. Phys. G: Nucl. Part. Phys. 34 (2007) 129-138).

de Boer, Fokke W N

2009-01-01

329

The search for a standard model Higgs at the LHC and electron identification using transition radiation in the ATLAS tracker  

Energy Technology Data Exchange (ETDEWEB)

The large Hadron Collider (LHC) will be ready for proton-proton collisions in the year 2005 and the ATLAS detector will be one of the two experiments at the LHC which will explore a new and higher energy range for particle physics. In this thesis, an analysis of the power of the ATLAS detector to detect a Standard Model Higgs boson has been performed. It is shown that it will be possible to discover a Higgs particle across the complete mass range from the lower limit defined by the reach of the LEP2 collider experiments to the upper theoretical limit around 1 TeV. The role of the inner tracking detector of ATLAS for the detection of conversions and the identification of the primary vertex in the detection of a Higgs particle in the Higgs to two photon decay channel is demonstrated with a detailed detector simulation. The identification of a 1 TeV Higgs particle requires a good understanding of both the signal and the backgrounds. The related uncertainties are covered in detail and it is shown that the Higgs can be identified in the H{yields}WW{yields}lvjj, H{yields}ZZ{yields}llvv and H{yields}ZZ{yields}lljj decay channels. The Transition Radiation Tracker (TRT) is a combined tracking and electron identification device which will be a part of the inner tracking detector of ATLAS. For a prototype of the TRT the electron identification performance is analysed and it is shown that the full scale TRT together with the calorimeters will provide the electron identification power required for a clean electron and photon signal at the LHC. For the prototype a rejection factor of 100 against pions was achieved with an electron efficiency of 90%. the importance of the TRT for a clear detection of a Higgs particle is demonstrated. 82 refs, figs, tabs.

Egede, U.

1998-01-01

330

The search for a standard model Higgs at the LHC and electron identification using transition radiation in the ATLAS tracker  

International Nuclear Information System (INIS)

The large Hadron Collider (LHC) will be ready for proton-proton collisions in the year 2005 and the ATLAS detector will be one of the two experiments at the LHC which will explore a new and higher energy range for particle physics. In this thesis, an analysis of the power of the ATLAS detector to detect a Standard Model Higgs boson has been performed. It is shown that it will be possible to discover a Higgs particle across the complete mass range from the lower limit defined by the reach of the LEP2 collider experiments to the upper theoretical limit around 1 TeV. The role of the inner tracking detector of ATLAS for the detection of conversions and the identification of the primary vertex in the detection of a Higgs particle in the Higgs to two photon decay channel is demonstrated with a detailed detector simulation. The identification of a 1 TeV Higgs particle requires a good understanding of both the signal and the backgrounds. The related uncertainties are covered in detail and it is shown that the Higgs can be identified in the H?WW?lvjj, H?ZZ?llvv and H?ZZ?lljj decay channels. The Transition Radiation Tracker (TRT) is a combined tracking and electron identification device which will be a part of the inner tracking detector of ATLAS. For a prototype of the TRT the electron identification performance is analysed and it is shown that the full scale TRT together with the calorimeters will provide the electron identification power required for a clean electron and photon signal at the LHC. For the prototype a rejection factor of 100 against pions was achieved with an electron efficiency of 90%. the importance of the TRT for a clear detection of a Higgs particle is demonstrated

331

Search for a Permanent Electric Dipole Moment of the Mercury Atom  

International Nuclear Information System (INIS)

There has been exciting progress in recent years in the search for a permanent electric dipole moment (EDM) of an atom, a molecule, or the neutron. An EDM along the axis of spin can exist only if time reversal symmetry (T) is violated. Although such a dipole has not yet been detected, mainstream theories of possible new physics, such as Supersymmetry, predict the existence of EDMs within reach of modern experiments. Here I discuss the results of our new experimental search for a permanent electric dipole moment of 199Hg utilizing a stack of four vapor cells. We find d(199Hg) (0.49±1.29stat±0.76syst)x10-29 e cm, and interpret this as a new upper bound, d(199Hg)-29 e cm(95% C.L.). This result improves our previous 199Hg limit by a factor of 7, and can be used to set new constraints on CP violation in physics beyond the Standard Model.

2009-12-17

332

Detection of EDM defects under Monju support plate using experimental data from remote field eddy current probes and a multi-frequency algorithm  

International Nuclear Information System (INIS)

This paper describes detection of electro-discharged machine (EDM) defects in magnetic steam generator (SG) tubes of Monju fast breeder reactor (FBR). The EDM defects are located under support plate (SP), on the outer tube surface and they are detected by a remote field eddy current probe. Using the experimental measurements and a multi frequency algorithm, the defect signal can be extracted from the SP signal. The parameters of the multi-frequency algorithm were calculated by comparing SP measurements with two-dimensional finite element simulations (FEM). (author)

2006-07-01

333

Data mining and accelerated electronic structure theory as a tool in the search for new functional materials  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A highly accelerated electronic structure implementation and data mining algorithms have been combined with structural data from the inorganic crystal structure database to generate materials properties for about 22,000 inorganic compounds. It is shown how data mining algorithms employed on the database can identify new functional materials with desired materials properties, resulting in a prediction of 136 novel materials with potential for use as detector materials for ionizing radiation. T...

Ortiz, Carlos; Eriksson, Olle; Klintenberg, Mattias

2009-01-01

334

Searching for authority: Archivists and electronic records in the New World at the Fin-de-Siecle  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The 1990's marked a turning point for archivists and electronic records management (ERM). Major conceptual solutions for ERM were proposed, and while these approaches have been adopted by some they have also generated intense debate and discussion. Three questions continue to remain unanswered. What is the authority for these approaches? How pervasive have these approaches been in influencing archival practice? How well known are these approaches across the archives field? This paper attempts...

Cox, Richard J.

2000-01-01

335

Energy levels and lifetimes of Gd IV and enhancement of the electron dipole moment  

CERN Document Server

We have calculated energy levels and lifetimes of 4f7 and 4f6 5d configurations of Gd IV using Hartree-Fock and configuration interaction methods. This allows us to reduce significantly the uncertainty of the theoretical determination of the electron electric dipole moment (EDM) enhancement factor in this ion and, correspondingly, in gadolinium-containing garnets for which such measurements were recently proposed. Our new value for the EDM enhancement factor of Gd+3 is -2.2 +- 0.5. Calculations of energy levels and lifetimes for Eu~III are used to control the accuracy.

Dzuba, V A; Johnson, W R; Safronova, U I

2002-01-01

336

Fabrication of a miniature diamond grinding tool using a hybrid process of micro-EDM and co-deposition  

Science.gov (United States)

A novel miniature diamond grinding tool usable for the precise micro-grinding of miniature parts is presented. A hybrid process that combines 'micro-EDM' with 'precision co-deposition' is proposed. The metal substrate is micro-EDMed to a 50 µm diameter and micro diamonds with 0-2 µm grains are 'electroformed' on the substrate surface, producing a miniature multilayered grinding tool. Nickel and diamond act as binders and cutters, respectively. A partition plate with an array of drilled holes is designed to ensure good convection in the electroforming solution. The dispersion of diamond grains and displacement of nickel ions are noticeably improved. A miniature funnel mould enables the diamond grains to converge towards the cathode to increase their deposition probability on the substrate, thereby improving their distribution on the substrate surface. A micro ZrO2 ceramic ferrule is finely ground by the developed grinding tool and then yields a surface roughness of Ra = 0.085 µm. The proposed approach is applied during the final machining process.

Chen, Shun-Tong; Lai, Yun-Cheng; Liu, Ching-Chang

2008-05-01

337

Study on an evaluation method of micro CMM spherical stylus tips by µ-EDM on-machine measurement  

Science.gov (United States)

This paper describes an on-machine measurement function of a micro electro-discharge machine (µ-EDM) to evaluate the quality of micro ball-ended stylus tips fabricated by a combination of wire-electro-discharge grinding (WEDG) and one-pulse-electro-discharge (OPED) technology. A low-voltage contacting trigger function without any capacitor between a stationary wire and the spindle of a µ-EDM was used to measure the outer profile and evaluate the forming quality. The measurement results show that the deviation of the largest radius between the micro ball-ended tip and stem is approximately 3 µm. Moreover, OPED/WEDG is also easily able to produce high-quality micro spherical stylus tips with a standard deviation as small as 0.7 µm through use of sharp-needle-shaped electrode tools. With further improvements in electro-discharge position, OPED and WEDG technology are promising and excellent approaches for manufacturing micro coordinate measurement machine (CMM) spherical stylus tips.

Sheu, Dong-Yea

2010-07-01

338

Fabrication of a miniature diamond grinding tool using a hybrid process of micro-EDM and co-deposition  

International Nuclear Information System (INIS)

A novel miniature diamond grinding tool usable for the precise micro-grinding of miniature parts is presented. A hybrid process that combines 'micro-EDM' with 'precision co-deposition' is proposed. The metal substrate is micro-EDMed to a 50 µm diameter and micro diamonds with 0–2 µm grains are 'electroformed' on the substrate surface, producing a miniature multilayered grinding tool. Nickel and diamond act as binders and cutters, respectively. A partition plate with an array of drilled holes is designed to ensure good convection in the electroforming solution. The dispersion of diamond grains and displacement of nickel ions are noticeably improved. A miniature funnel mould enables the diamond grains to converge towards the cathode to increase their deposition probability on the substrate, thereby improving their distribution on the substrate surface. A micro ZrO2 ceramic ferrule is finely ground by the developed grinding tool and then yields a surface roughness of Ra = 0.085 µm. The proposed approach is applied during the final machining process

2008-05-01

339

Laser in the axial electric field as a tool to search for P-, T- invariance violation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We consider rotation of polarization plane of the laser light when a gas laser is placed in a longitudinal electric field (10~kV/cm). It is shown that residual anisotropy of the laser cavity 10^{-6} and the sensitivity to the angle of polarization plane rotation about 10^{-11} -10^{-12} rad allows one to measure an electron EDM with the sensitivity about 10^{-30} e cm.

Baryshevsky, V. G.; Cherkas, S. L.; Matsukevich, D. N.

2005-01-01

340

Professional Microsoft search fast search, Sharepoint search, and search server  

CERN Document Server

Use Microsoft's latest search-based technology-FAST search-to plan, customize, and deploy your search solutionFAST is Microsoft's latest intelligent search-based technology that boasts robustness and an ability to integrate business intelligence with Search. This in-depth guide provides you with advanced coverage on FAST search and shows you how to use it to plan, customize, and deploy your search solution, with an emphasis on SharePoint 2010 and Internet-based search solutions.With a particular appeal for anyone responsible for implementing and managing enterprise search, this book presents t

Bennett, Mark; Kehoe, Miles; Voskresenskaya, Natalya

2010-01-01

 
 
 
 
341

Constraints on dark matter models from a Fermi LAT search for high-energy cosmic-ray electrons from the Sun  

Science.gov (United States)

During its first year of data taking, the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope has collected a large sample of high-energy cosmic-ray electrons and positrons (CREs). We present the results of a directional analysis of the CRE events, in which we searched for a flux excess correlated with the direction of the Sun. Two different and complementary analysis approaches were implemented, and neither yielded evidence of a significant CRE flux excess from the Sun. We derive upper limits on the CRE flux from the Sun’s direction, and use these bounds to constrain two classes of dark matter models which predict a solar CRE flux: (1) models in which dark matter annihilates to CREs via a light intermediate state, and (2) inelastic dark matter models in which dark matter annihilates to CREs.

Ajello, M.; Atwood, W. B.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Bouvier, A.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cecchi, C.; Charles, E.; Chekhtman, A.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cutini, S.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Do Couto E Silva, E.; Drell, P. S.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gehrels, N.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Iafrate, G.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kuss, M.; Latronico, L.; Lionetto, A. M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Ritz, S.; Schalk, T. L.; Sgrò, C.; Siegal-Gaskins, J.; Siskind, E. J.; Smith, P. D.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Tibaldo, L.; Tosti, G.; Troja, E.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vilchez, N.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Zimmer, S.

2011-08-01

342

Search for New Physics in High Mass Electron-Positron Events in ppbar Collisions at $\\sqrt{s}$ = 1.96 TeV  

CERN Document Server

We report the results of a search for a narrow resonance in electron-positron events in the invariant mass range of 150-950 GeV/c^2 using 1.3 fb^-1 of ppbar collision data at $\\sqrt{s}$ = 1.96 TeV collected by the CDF II detector at Fermilab. No significant evidence of such a resonance is observed and we interpret the results to exclude the standard model-like Z' with a mass below 923 GeV/c^2 and the Randall-Sundrum graviton with a mass below 807 GeV/c^2 for k/M_pl=0.1, both at the 95% confidence level. Combining with di-photon data excludes the Randall-Sundrum graviton for masses below 889 GeV/c^2 for k/M_pl=0.1.

Aaltonen, T; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bölla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, Yu; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carrillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca-Almenar, C; Cuevas-Maestro, J; Culbertson, R; Cully, J C; Da Ronco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; De Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, Mauro; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Dorr, C; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernández, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; García, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gómez, G; Gómez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimarães da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Höcker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lu, R S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Mäki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martinez-Ballarin, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtälä, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Movilla-Fernández, P A; Mülmenstädt, J; Mukherjee, A; Müller, T; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V

2007-01-01

343

"Do Users Do What They Think They Do?"- A Comparative Study of User Perceived and Actual Information Searching Behaviour in the National Electronic Library of Infection  

Science.gov (United States)

In the last decade, the Internet has profoundly changed the delivery of healthcare. Medical websites for professionals and patients are playing an increasingly important role in providing the latest evidence-based knowledge for professionals, facilitating virtual patient support groups, and providing an invaluable information source for patients. Information seeking is the key user activity on the Internet. However, the discrepancy between what information is available and what the user is able to find has a profound effect on user satisfaction. The UK National electronic Library of Infection (NeLI, www.neli.org.uk) and its subsidiary projects provide a single-access portal for quality-appraised evidence in infectious diseases. We use this national portal, as test-bed for investigating our research questions. In this paper, we investigate actual and perceived user navigation behaviour that reveals important information about user perceptions and actions, in searching for information. Our results show: (i) all users were able to access information they were seeking; (ii) broadly, there is an agreement between "reported" behaviour (from questionnaires) and "observed" behaviour (from web logs), although some important differences were identified; (iii) both browsing and searching were equally used to answer specific questions and (iv) the preferred route for browsing for data on the NeLI website was to enter via the "Top Ten Topics" menu option. These findings provide important insights into how to improve user experience and satisfaction with health information websites.

Roy, Anjana; Kostkova, Patty; Catchpole, Mike; Carson, Ewart

344

Searching for seismo-ionospheric earthquakes precursors: Total Electron Content disturbances before 2005-2006 seismic events  

CERN Document Server

During earthquakes preparation periods significant disturbances in the ionospheric plasma density are often observed. These anomalies are caused by lithosphere-atmosphere-ionosphere interaction, particularly by the seismic electric field penetrating from the ground surface into the ionosphere. The seismic electric field produces electromagnetic EB drift changing plasma density over the epicenter region and magnetically conjugated area. The paper is devoted to analysis of regular Global Positioning System observations and revelation of seismo-ionospheric precursors of earthquakes in Total Electron Content (TEC) of the ionosphere. Global and regional relative TEC disturbances maps (%) have been plotted for 2005-2006 M6, D<60 km seismic events and analyzed in order to determine general features of precursors. The obtained results agree with the recent published case-study investigations.

Romanovskaya, Yu V; Zolotov, O V; Starikova, N A; Lopatiy, V Z

2012-01-01

345

Zeeman interaction in ThO H3?1 for the electron electric-dipole-moment search  

Science.gov (United States)

The current limit on the electron's electric dipole moment, |de|geometric phases, due in part to its ?-doublet structure. These systematics can be further suppressed by operating the experiment under conditions where the g-factor difference between the ? doublets is minimized. We consider the g factors of the ThO H3?1 state both experimentally and theoretically, including dependence on ? doublets, the rotational level, and the external electric field. The calculated and measured values are in good agreement. We find that the g-factor difference between ? doublets is smaller in J =2 than in J =1 and reaches zero at an experimentally accessible electric field. This means that the H ,J=2 state should be even more robust against a number of systematic errors compared to H ,J=1.

Petrov, A. N.; Skripnikov, L. V.; Titov, A. V.; Hutzler, N. R.; Hess, P. W.; O'Leary, B. R.; Spaun, B.; DeMille, D.; Gabrielse, G.; Doyle, J. M.

2014-06-01

346

Search Cloud  

Science.gov (United States)

... Topics Drugs & Supplements Videos & Cool Tools ESPAÑOL Search Cloud To use the sharing features on this page, ... of Top 110 zoloft Share the MedlinePlus search cloud with your users by embedding our search cloud ...

347

A lower bound on hadronic EDMs from CP violation in D0-D-bar0 mixing in SUSY alignment models  

International Nuclear Information System (INIS)

The SM predictions for CP violating effects in D meson systems are highly suppressed at the per mill level. Therefore, any experimental evidence for a sizable CP violation in D0-D-bar0 mixing would unambiguously point towards a New Physics (NP) signal. Within supersymmetric scenarios, the popular alignment models can naturally account for large, non-standard effects in D0-D-bar0 mixing. We demonstrate that, within alignment models, detectable CP violating effects in D0-D-bar0 mixing would unambiguously imply a lower bound for the electric dipole moment (EDM) of hadronic systems, like the neutron EDM and the mercury EDM, in the reach of future experimental sensitivities. The simultaneous evidence of CP violation in D meson systems together with non-vanishing hadronic EDMs would strongly support the idea of SUSY alignment models and disfavour gauge-mediated SUSY breaking models, SUSY models with MFV and non-Abelian SUSY flavour models. As a byproduct of our analysis, we study the correlation between the time dependent CP asymmetry in decays to CP eigenstates Sf and the semileptonic asymmetry aSL both model independently and in SUSY alignment models.

2010-05-03

348

Search for a heavy particle decaying into electron-muon in $pp$ collisions at $\\sqrt{s} = 7$ TeV at LHC with the ATLAS detector  

CERN Document Server

In this thesis, a search for $e\\mu$ resonance of $\\tau$ sneutrino ($\\tilde{\\mu}_{\\tau}$) decay using $pp$ collision data of $\\sqrt{s}=7$ TeV collected by the ATLAS experiment at LHC is described. The Standard Model (SM) processes having electron and muon in the final state are estimated with Monte Carlo simulations. A matrix method was used to estimate the jet fake background. We first analysed the 35 pb$^{-1}$ data taken in 2010 from March to December and later updated the results with 1.07 fb$^{-1}$ data taken in 2011 from March 2011 to June 2011. Seeing no significance deviation of data from the SM prediction, we set the limit on the $\\tau$ sneutrino mass and also the limit of coupling parameter as function of $\\tilde{\\mu}_{\\tau}$ mass. $\\tau$ sneutrino of $m275\\GeV$. The limits on the production cross section of $\\tau$ sneutrino can also be interpreted to other models predicting a heavy particle decaying to electron and muon pair.

Zhang, Dongliang; Hou, S

349

Measurement of the Inclusive Electron Cross-Section from Heavy-Flavour Decays and Search for Compressed Supersymmetric Scenarios with the ATLAS Experiment  

CERN Document Server

The first part of this thesis presents the measurement of the inclusive cross-section for electron production from heavy-flavour decays in the electron transverse momentum range 7 GeV < pT < 26 GeV using 1.3 pb?1 of 7 TeV proton-proton collision data collected by the ATLAS experiment at the Large Hadron Collider in 2010. The measured value of the cross-section within the fiducial range of the analysis is ?_e^HF = 0.946 ± 0.020(stat.) ± 0.146(syst.) ± 0.032(lumi.) ?b. Theoretical predictions are in good agreement with the measurement. The second part of this thesis is a search for compressed supersymmetric scenarios in events with missing transverse energy, jets, and one isolated low-pT lepton in the final state using 4.7 fb-1 of ATLAS data collected at 7 TeV center-of-mass energy in 2011. No significant excess of events over the Standard Model expectation is observed and exclusion limits are derived for a number of supersymmetric models.

Backes, Moritz

350

Remedial design through effective electronic associations  

Energy Technology Data Exchange (ETDEWEB)

Black and Veatch Special Projects Corp. (BVSPC) used an environmental data management system (EDMS) to consolidate x-ray fluorescence (XRF), global positioning system (GPS), and laboratory analytical data into a unique and flexible electronic database. Cost savings were acknowledged in all phases of the remedial design due to the development and use of the EDMS and its distinct associations with various electronic software packages. The EDMS allowed effective and efficient completion of the remedial design investigation of the Oronogo-Duenweg Mining Belt Site. The Site is a 125-year old mining community in Jasper County, Missouri. Approximately 6,500 residences are now located within the 60 square-mile Superfund Site where lead and zinc were mined. Smelting and mining activities were conducted in several areas throughout the community. These operations left approximately 9 million tons of mine wastes at the Site upon completion of the mining activities. The purpose of the remedial design investigation was to quantify and identify the residential yards that were adversely affected by these activities.

Deis, J.L.; Wankum, R.D.

1999-07-01

351

The selection of phase composition of silicon nitride ceramics for shaping with the use of EDM machining  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: The purpose of this study is the selection of phase composition of Si3N4 matrix ceramics with the addition of conducting phases so as to make shaping of those materials possible by means of electro discharge machining (EDM. Silicon nitride matrix materials with the addition of oxide phases (Al2O3, MgO, ZrO2 and conducting phases (TiB2, TiN were sintered by the method of SPS (Spark Plasma Sintering. Additionally the effect of oxide phases on silicon nitride sintering capacity, the value of electric resistance of nitride ceramics depending on the addition of a conducting phase and the effect of sintering parameters on selected features of produced materials were determined.Design/methodology/approach: Materials were sintered with the use of a SPS device marked with FCT-HP D 5. Apparent density ?p was measured by the hydrostatic method. Hardness was determined by the Vicker’s method at the load of 980.7 mN with the use of a Future Tech Corp digital hardness tester FM7. For the purpose of those tests a surface was prepared with the use of a Struers cutting grinder ACUTOM. Measurements of Young’s modulus for sintered samples were carried out using a ultrasonic method of transverse and longitudinal wave speed measurement with the use of a Panametrics Epoch III detector. Resistance measurement was done with the use of Wheatstone and Thomson technical bridges.Findings: The addition of titanium nitride had no effect on the reduction of electric resistance of Si3N4 matrix ceramics. The lack of electric conductivity of those materials is the result of used additions influencing sintering capacity, mainly magnesium oxide. Si3N4 matrix materials with the addition of titanium diboride are characterised by low electrical resistance with high physical and mechanical features maintained. Electric conductivity of those materials and the initial electro discharge cutting attempts prove that it is possible to shape Si3N4 matrix ceramic materials with the addition of a TiB2 phase with the use of EDM process.Practical implications: The use of EDM will enable the production of elements with complicated shapes (impossible to achieve by other shaping methods from ceramic materials (with Si3N4 matrix.Originality/value: By the appropriate selection of a conducting phase addition it is possible to increase electric conductivity of silicone nitride matrix ceramics, for which it is possible to shape products by means of electro discharge machining.

P. Putyra

2011-09-01

352

Electronics  

CERN Multimedia

Although most people would scarcely be able to make it through the day without using some type of electronic device-computers, televisions, and MP3 players, to name a few-the inner workings of such devices remain a mystery to many. This insightful volume examines various components, such as electron tubes and semiconductors, that have been essential to electronics over the years, as well as the history of the field in general and its applications in everyday life.

Hollar, Sherman

2012-01-01

353

Electrons  

International Nuclear Information System (INIS)

Fast electrons are used to produce isotopes for studying the cooper metabolism: Cu-64 in a cyclotron and Cu-67 in a linear accelerator. Localized electrons are responsible for the chemical and physiological characteristics of the trace elements. Studied are I, Cu, Co, Zn, Mo, Mn, Fe, Se, Mg. The Cu/Mo and Cu/Zn interactions are investigated. The levels of molybdenum, sulfate and zinc in the food are analysed. The role of the electrons in free radicals is discussed. The protection action of peroxidases and super oxidases against electron dangerous effect on normal physiology is also considered. Calculation of radiation damage and radiation protection is made. (author)

1994-09-12

354

Straight hole micro EDM with a cylindrical tool using a variable capacitance method accompanied by ultrasonic vibration  

Science.gov (United States)

A micro hole machined by EDM with a cylindrical electrode has different hole entrance and exit diameters. This taper shape of the micro hole is caused both by tool wear and by eroded particles that induce secondary discharge during hole machining. In this paper, a novel method is proposed to reduce the difference between the entrance and exit diameters of the holes. The effects of feeding depth, applied capacitance and machining time on the formation of the tapered shape were observed experimentally. Based on these experiments, ultrasonic vibration was applied to reduce the secondary discharge and electrode wear, and capacitance was varied when the tool was approaching the exit of the hole. Using the proposed method, a straight micro hole was successfully fabricated.

Kim, Dong Jun; Yi, Sang Min; Lee, Young Soo; Chu, Chong Nam

2006-05-01

355

Search Patterns  

CERN Document Server

What people are saying about Search Patterns "Search Patterns is a delight to read -- very thoughtful and thought provoking. It's the most comprehensive survey of designing effective search experiences I've seen." --Irene Au, Director of User Experience, Google "I love this book! Thanks to Peter and Jeffery, I now know that search (yes, boring old yucky who cares search) is one of the coolest ways around of looking at the world." --Dan Roam, author, The Back of the Napkin (Portfolio Hardcover) "Search Patterns is a playful guide to the practical concerns of search interface design. It cont

Morville, Peter

2010-01-01

356

Search for new physics in high mass electron-positron events in p anti-p collisions at s**(1/2) = 1.96-TeV  

Energy Technology Data Exchange (ETDEWEB)

We report the results of a search for a narrow resonance in electron-positron events in the invariant mass range of 150-950 GeV/c{sup 2} using 1.3 fb{sup -1} of p{bar p} collision data at {radical}s=1.96 TeV collected by the CDF II detector at Fermilab. No significant evidence of such a resonance is observed and we interpret the results to exclude the standard model-like Z{prime} with a mass below 923 GeV/c{sup 2} and the Randall-Sundrum graviton with a mass below 807 GeV/c{sup 2} for k/{bar M}{sub pl} = 0.1, both at the 95% confidence level. Combining with di-photon data excludes the Randall-Sundrum graviton for masses below 889 GeV/c{sup 2} for k/{bar M}{sub pl} = 0.1

Aaltonen, T.; Abulencia, A.; Adelman, J.; Affolder, Anthony Allen; Akimoto, T.; Albrow, Michael G.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Anikeev, K.; Annovi, A. /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara

2007-07-01

357

Candidate molecular ions for an electron electric dipole moment experiment  

Science.gov (United States)

This paper is a theoretical work in support of a newly proposed experiment [R. Stutz and E. Cornell, Bull. Am. Soc. Phys. 89, 76 (2004)] that promises greater sensitivity to measurements of the electron’s electric dipole moment (EDM) based on the trapping of molecular ions. Such an experiment requires the choice of a suitable molecule that is both experimentally feasible and possesses an expectation of a reasonable EDM signal. We find that the molecular ions PtH+ and HfH+ are both suitable candidates in their low-lying ?3 states. In particular, we anticipate that the effective electric fields generated inside these molecules are approximately 73 and -17GV/cm , respectively. As a byproduct of this discussion, we also explain how to make estimates of the size of the effective electric field acting in a molecule, using commercially available nonrelativistic molecular structure software.

Meyer, Edmund R.; Bohn, John L.; Deskevich, Michael P.

2006-06-01

358

Search Combinators  

CERN Multimedia

The ability to model search in a constraint solver can be an essential asset for solving combinatorial problems. However, existing infrastructure for defining search heuristics is often inadequate. Either modeling capabilities are extremely limited or users are faced with a general-purpose programming language whose features are not tailored towards writing search heuristics. As a result, major improvements in performance may remain unexplored. This article introduces search combinators, a lightweight and solver-independent method that bridges the gap between a conceptually simple modeling language for search (high-level, functional and naturally compositional) and an efficient implementation (low-level, imperative and highly non-modular). By allowing the user to define application-tailored search strategies from a small set of primitives, search combinators effectively provide a rich domain-specific language (DSL) for modeling search to the user. Remarkably, this DSL comes at a low implementation cost to the...

Schrijvers, Tom; Wuille, Pieter; Samulowitz, Horst; Stuckey, Peter J

2012-01-01

359

Search for WH production with a light Higgs boson decaying to prompt electron-jets in proton-proton collisions at $\\sqrt{s}$=7 TeV with the ATLAS detector  

CERN Document Server

A search is performed for WH production with a light Higgs boson decaying to hidden-sector particles resulting in clusters of collimated electrons, known as electron-jets. The search is performed with 2.04 fb-1 of data collected in 2011 with the ATLAS detector at the LHC in proton-proton collisions at $\\sqrt{s}$=7 TeV. One event satisfying the signal selection criteria is observed, which is consistent with the expected background rate. Limits on the product of the WH production cross section and the branching ratio of a Higgs boson decaying to prompt electron-jets are calculated as a function of a Higgs boson mass in the range from 100 GeV to 140 GeV.

Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdelalim, Ahmed Ali; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Astbury, Alan; Atkinson, Markus; Auerbach, Benjamin; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagnaia, Paolo; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Begel, Michael; Behar Harpaz, Silvia; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bittner, Bernhard; Black, Curtis; Black, James; Black, Kevin; Blair, Robert

2013-01-01

360

Search for WH production with a light Higgs boson decaying to prompt electron-jets in proton-proton collisions at \\sqrt {s}=7 TeV with the ATLAS detector  

Science.gov (United States)

A search is performed for WH production with a light Higgs boson decaying to hidden-sector particles resulting in clusters of collimated electrons, known as electron-jets. The search is performed with 2.04 fb-1 of data collected in 2011 with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at \\sqrt {s}=7\\,{ { TeV}} . One event satisfying the signal selection criteria is observed, which is consistent with the expected background rate. Limits on the product of the WH production cross section and the branching ratio of a Higgs boson decaying to prompt electron-jets are calculated as a function of a Higgs boson mass in the range from 100 to 140 GeV.

Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdelalim, A. A.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Adomeit, S.; Adragna, P.; Adye, T.; Aefsky, S.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahsan, M.; Aielli, G.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alam, M. A.; Albert, J.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alonso, F.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amelung, C.; Ammosov, V. V.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aoun, S.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Arfaoui, S.; Arguin, J.-F.; Argyropoulos, S.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Artamonov, A.; Artoni, G.; Arutinov, D.; Asai, S.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Astbury, A.; Atkinson, M.; Auerbach, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, D.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baccaglioni, G.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagnaia, P.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, S.; Balek, P.; Balli, F.; Banas, E.; Banerjee, P.; Banerjee, Sw; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartsch, V.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battaglia, A.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beale, S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Begel, M.; Behar Harpaz, S.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellomo, M.; Belloni, A.; Beloborodova, O.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernat, P.; Bernhard, R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Bertella, C.; Bertin, A.; Bertolucci, F.; Besana, M. I.; Besjes, G. J.; Besson, N.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biscarat, C.; Bittner, B.; Black, C. W.; Black, J. E.; Black, K. M.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blocki, J.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boek, T. T.; Boelaert, N.; Bogaerts, J. A.; Bogdanchikov, A.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bolnet, N. M.; Bomben, M.; Bona, M.; Boonekamp, M.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borjanovic, I.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Branchini, P.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Bremer, J.; Brendlinger, K.; Brenner, R.; Bressler, S.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Broggi, F.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brown, G.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.; Buanes, T.; Buat, Q.

2013-04-01

 
 
 
 
361

Investigation of the effect of process parameters on the formation and characteristics of recast layer in wire-EDM of Inconel 718  

Energy Technology Data Exchange (ETDEWEB)

Inconel 718 is a high nickel content superalloy possessing high strength at elevated temperatures and resistance to oxidation and corrosion. The non-traditional manufacturing process of wire-electrical discharge machining (EDM) possesses many advantages over traditional machining during the manufacture of Inconel 718 parts. However, certain detrimental effects are also present and are due in large part to the formation of the recast layer. An experimental investigation was conducted to determine the main EDM parameters which contribute to recast layer formation in Inconel 718. It was found that average recast layer thickness increased primarily with energy per spark, peak discharge current, and current pulse duration. Over the range of parameters tested, the recast layer was observed to be between 5 and 9 {micro}m in average thickness, although highly variable in nature. The recast material was found to possess in-plane tensile residual stresses, as well as lower hardness and elastic modulus than the bulk material.

Newton, Thomas R [Georgia Institute of Technology; Melkote, Shreyes N [Georgia Institute of Technology; Watkins, Thomas R [ORNL; Trejo, Rosa M [ORNL; Riester, Laura [ORNL

2009-01-01

362

Analysis of Influence of micro-EDM Parameters on MRR, TWR and Ra in Machining Ni-Ti Shape Memory Alloy  

Directory of Open Access Journals (Sweden)

Full Text Available In the micro-machining and MEMS industry, micro-Electrical discharge machining (?-EDM is an important process. In this paper, the Taguchi design approach has been employed to investigate the micro-EDM parameters in order to achieve the highest Material Removal Rate (MRR, good surface quality and low Tool Wear Rate (TWR while machining Ni-Ti based Shape Memory Alloy (SMA. Based on these investigations, it has been observed that MRR is highly influenced by capacitance, discharge voltage and depends upon electrode material. TWR and Ra were found to be better at low energy levels. Tungsten electrode is recommended for better surface roughness and brass electrode for better MRR. SEM images have been used to observe the dimensional accuracy of micro-holes produced.

Mohammed Sarvar Rasheed

2012-10-01

363

Electronics  

International Nuclear Information System (INIS)

Some of the electronic equipment used in pulse counting and mean current radiation detection systems is described. This includes the high voltage supply, amplifier, amplitude discriminator, scalers or counters, ratemeters, single-channel pulse height analyser, multi-channel pulse height analyser, d.c. amplifiers, coincidence and anticoincidence units and gain stabilisers

1982-10-01

364

Clustering search  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the Clustering Search (CS as a new hybrid metaheuristic, which works in conjunction with other metaheuristics, managing the implementation of local search algorithms for optimization problems. Usually the local search is costly and should be used only in promising regions of the search space. The CS assists in the discovery of these regions by dividing the search space into clusters. The CS and its applications are reviewed and a case study for a problem of capacitated clustering is presented.

Alexandre César Muniz de Oliveira

2013-04-01

365

Working with Kolya Uraltsev for twenty-five years about Fundamental Dynamics and Symmetries and for the future -- like CP Violation & EDMs  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Working with Kolya Uraltsev was a real `marvel' for me about CP & T violation, QCD & its impact on transitions in heavy flavor hadrons, EDMs etc. etc. The goal was (and still is) to define fundamental parameters dynamics, how to measure them and compare SM forces with New Dynamics using the best theoretical tools. The correlations of them with accurate data were crucial for Kolya. Here is a review of CP asymmetries in $B$ & $D$ mesons and $\\tau$ decays, the impact of perturb...

Bigi, I. I.

2013-01-01

366

High electric field development for the SNS nEDM Experiment  

CERN Document Server

A new experiment to search for the permanent electric dipole moment of the neutron is being developed for installation at the Spallation Neutron Source at Oak Ridge National Laboratory. This experiment will be performed in liquid helium at ? 0:4 K and requires a large electric field (E ~ 75 kV/cm) to be applied in liquid helium. We have constructed a new HV test apparatus to study electric breakdown in liquid helium. Initial results demonstrated that it is possible to apply fields exceeding 100 kV/cm in a 1 cm gap between two electropolished stainless steel electrodes12 cm in diameter for a wide range of pressures.

Ito, T M; Clayton, S M; Crawford, C; Currie, S A; Griffith, W C; Ramsey, J C; Roberts, A L; Schmid, R; Seidel, G M; Wagner, D; Yao, W

2014-01-01

367

Search for electric dipole moment in 129Xe atom using active nuclear spin maser  

Directory of Open Access Journals (Sweden)

Full Text Available An experimental search for an electric dipole moment in the diamagnetic atom 129Xe is in progress through the precision measurement of spin precession frequency using an active nuclear spin maser. A 3He comagnetometer has been incorporated into the active spin maser system in order to cancel out the long-term drifts in the external magnetic field. Also, a double-cell geometry has been adopted in order to suppress the frequency shifts due to interaction with polarized Rb atoms. The first EDM measurement with the 129Xe active spin maser and the 3He comagnetometer has been conducted.

Ichikawa Y.

2014-03-01

368

Search for electric dipole moment in 129Xe atom using active nuclear spin maser  

Science.gov (United States)

An experimental search for an electric dipole moment in the diamagnetic atom 129Xe is in progress through the precision measurement of spin precession frequency using an active nuclear spin maser. A 3He comagnetometer has been incorporated into the active spin maser system in order to cancel out the long-term drifts in the external magnetic field. Also, a double-cell geometry has been adopted in order to suppress the frequency shifts due to interaction with polarized Rb atoms. The first EDM measurement with the 129Xe active spin maser and the 3He comagnetometer has been conducted.

Ichikawa, Y.; Chikamori, M.; Ohtomo, Y.; Hikota, E.; Sakamoto, Y.; Suzuki, T.; Bidinosti, C. P.; Inoue, T.; Furukawa, T.; Yoshimi, A.; Suzuki, K.; Nanao, T.; Miyatake, H.; Tsuchiya, M.; Yoshida, N.; Shirai, H.; Ino, T.; Ueno, H.; Matsuo, Y.; Fukuyama, T.; Asahi, K.

2014-03-01

369

Electronics  

CERN Document Server

Owen Bishop's First Course starts with the basics of electricity and component types, introducing students to practical work almost straight away. No prior knowledge of electronics is required. The approach is student-centred with self-test features to check understanding, including numerous activities suitable for practicals, homework and other assignments. Multiple choice questions are incorporated throughout the text in order to aid student learning. Key facts, formulae and definitions are highlighted to aid revision, and theory is backed up by numerous examp

Bishop, Owen

2010-01-01

370

Surface integrity evolution from main cut mode to finish trim cut mode in W-EDM of shape memory alloy  

Science.gov (United States)

Shape memory alloys such as Nitinol are widely used in medical, aerospace, actuator, and machine tool industries. However, Nitinol is a very difficult-to-machine material due to the superelasticity, high ductility, and severe strain-hardening. The machined surface should have tailored micro texture to enhance cell adhesion. This study explores the process capability of W-EDM (DI-water based dielectric) in machining Ni50.8Ti49.2 by one main cut (MC) mode followed by four trim cut (TC) modes. Experimental results show that the 6-sigma distributions of Ra are very different between MC mode and finish TC mode. Thick white layers (2-8 ?m) with microcracks in MC mode and very thin white layers (0-2 ?m) free of those defects in finish TC mode can be observed. However, microcracks would not propagate into the heat affected zone (HAZ) below the white layer. The microhardness of white layer by TC mode is about 50% higher than that by MC mode. In addition, Ni is the dominant element for the measured microhardness.

Liu, J. F.; Li, L.; Guo, Y. B.

2014-07-01

371

Search for a heavy gauge boson W' in the final state with an electron and large missing transverse energy in pp collisions at $\\sqrt{s}$ = 7 TeV  

CERN Document Server

A search for a heavy gauge boson W' has been conducted by the CMS experiment at the LHC in the decay channel with an electron and large transverse energy imbalance, using proton-proton collision data corresponding to an integrated luminosity of 36 inverse picobarns. No excess above standard model expectations is seen in the transverse mass distribution of the electron-(missing E_T) system. Assuming standard-model-like couplings and decay branching fractions, a W' boson with a mass less than 1.36 TeV/$c^2$ is excluded at 95% confidence level.

Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hammer, Josef; Haensel, Stephan; Hartl, Christian; Hoch, Michael; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kasieczka, Gregor; Kiesenhofer, Wolfgang; Krammer, Manfred; Liko, Dietrich; Mikulec, Ivan; Pernicka, Manfred; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Teischinger, Florian; Waltenberger, Wolfgang; Walzel, Gerhard; Widl, Edmund; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Benucci, Leonardo; Cerny, Karel; De Wolf, Eddi A.; Janssen, Xavier; Maes, Thomas; Mucibello, Luca; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Selvaggi, Michele; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Adler, Volker; Beauceron, Stephanie; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Devroede, Olivier; Gonzalez Suarez, Rebeca; Kalogeropoulos, Alexis; Maes, Joris; Maes, Michael; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Charaf, Otman; Clerbaux, Barbara; De Lentdecker, Gilles; Dero, Vincent; Gay, Arnaud; Hammad, Gregory Habib; Hreus, Tomas; Marage, Pierre Edouard; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wickens, John; Costantini, Silvia; Grunewald, Martin; Klein, Benjamin; Marinov, Andrey; Mccartin, Joseph; Ryckbosch, Dirk; Thyssen, Filip; Tytgat, Michael; Vanelderen, Lukas; Verwilligen, Piet; Walsh, Sinead; Zaganidis, Nicolas; Basegmez, Suzan; Bruno, Giacomo; Caudron, Julien; Ceard, Ludivine; De Favereau De Jeneret, Jerome; Delaere, Christophe; Demin, Pavel; Favart, Denis; Giammanco, Andrea; Grégoire, Ghislain; Hollar, Jonathan; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Ovyn, Severine; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Schul, Nicolas; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Alves, Gilvan; De Jesus Damiao, Dilson; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Carvalho, Wagner; Da Costa, Eliza Melo; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Mundim, Luiz; Nogima, Helio; Oguri, Vitor; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Silva Do Amaral, Sheila Mara; Sznajder, Andre; De Almeida Dias, Flavia; Ferreira Dias, Marco Andre; Tomei, Thiago; De Moraes Gregores, Eduardo; Da Cunha Marinho, Franciole; Novaes, Sergio F.; Padula, Sandra; Darmenov, Nikolay; Dimitrov, Lubomir; Genchev, Vladimir; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Tcholakov, Vanio; Trayanov, Rumen; Vankov, Ivan; Dyulendarova, Milena; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Marinova, Evelina; Mateev, Matey; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Wang, Jian; Wang, Jian; Wang, Xianyou; Wang, Zheng; Xu, Ming; Yang, Min; Zang, Jingjing; Zhang, Zhen; Ban, Yong; Guo, Shuang; Guo, Yifei; Li, Wenbo; Mao, Yajun; Qian, Si-Jin; Teng, Haiyun; Zhang, Linlin; Zhu, Bo; Zou, Wei; Cabrera, Andrés; Gomez Moreno, Bernardo; Ocampo Rios, Alberto Andres; Osorio Oliveros, Andres Felipe; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Lelas, Karlo; Plestina, Roko; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Dzelalija, Mile; Brigljevic, Vuko; Duric, Senka; Kadija, Kreso; Morovic, Srecko; Attikis, Alexandros; Galanti, Mario; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A.; Rykaczewski, Hans; Assran, Yasser; Mahmoud, Mohammed; Hektor, Andi; Kadastik, Mario; Kannike, Kristjan; Müntel, Mait; Raidal, Martti; Rebane, Liis; Azzolini, Virginia; Eerola, Paula; Czellar, Sandor; Härkönen, Jaakko; Heikkinen, Mika Aatos; Karimäki, Veikko; Kinnunen, Ritva; Klem, Jukka; Kortelainen, Matti J.; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Ungaro, Donatella; Wendland, Lauri; Banzuzi, Kukka; Korpela, Arja; Tuuva, Tuure; Sillou, Daniel; Besancon, Marc; Choudhury, Somnath; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Ferri, Federico; Ganjour, Serguei; Gentit, François-Xavier; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Marionneau, Matthieu; Millischer, Laurent; Rander, John; Rosowsky, André; Shreyber, Irina; Titov, Maksym; Verrecchia, Patrice; Baffioni, Stephanie; Beaudette, Florian; Bianchini, Lorenzo

2011-01-01

372

Search for a heavy gauge boson W' in the final state with an electron and large missing transverse energy in pp collisions at $\\sqrt{s}$ = 7 TeV  

CERN Multimedia

A search for a heavy gauge boson $W^{\\prime}$ has been conducted by the CMS experiment at the LHC in the decay channel with an electron and large transverse energy imbalance, MET, using proton-proton collision data corresponding to an integrated luminosity of $36~\\mathrm{pb}^{-1}$. No excess above standard model expectations is seen in the transverse mass distribution of the electron-MET system. Assuming standard-model-like couplings and decay branching fractions, a $W^{\\prime}$ boson with a mass less than $1.32~\\mathrm{TeV}/c^2$ is excluded at the 95% confidence level.

Puigh, Darren

373

A measurement of hadron production cross sections for the simulation of accelerator neutrino beams and a search for muon-neutrino to electron-neutrino oscillations in the delta m**2 about equals 1-eV**2 region  

Energy Technology Data Exchange (ETDEWEB)

A measurement of hadron production cross-sections for the simulation of accelerator neutrino beams and a search for muon neutrino to electron neutrino oscillations in the {Delta}m{sup 2} {approx} 1 eV{sup 2} region. This dissertation presents measurements from two different high energy physics experiments with a very strong connection: the Hadron Production (HARP) experiment located at CERN in Geneva, Switzerland, and the Mini Booster Neutrino Experiment (Mini-BooNE) located at Fermilab in Batavia, Illinois.

Schmitz, David W.; /Columbia U.

2008-01-01

374

Candidate molecular ions for an electron electric dipole moment experiment  

International Nuclear Information System (INIS)

This paper is a theoretical work in support of a newly proposed experiment [R. Stutz and E. Cornell, Bull. Am. Soc. Phys. 89, 76 (2004)] that promises greater sensitivity to measurements of the electron's electric dipole moment (EDM) based on the trapping of molecular ions. Such an experiment requires the choice of a suitable molecule that is both experimentally feasible and possesses an expectation of a reasonable EDM signal. We find that the molecular ions PtH+ and HfH+ are both suitable candidates in their low-lying 3? states. In particular, we anticipate that the effective electric fields generated inside these molecules are approximately 73 and -17 GV/cm, respectively. As a byproduct of this discussion, we also explain how to make estimates of the size of the effective electric field acting in a molecule, using commercially available nonrelativistic molecular structure software

2006-06-01

375

Station search  

Station search Station name: NRFA reference: Tip: e.g. 54010 Gauging authority ref: Tip: e.g. 2010 Watercourse: Tip: e.g. Stour Hydrometric Area: Tip: e.g. Severn Gauging authority region: Unspecified Anglian Midlands Rivers Agency (NI) North East North West SEPA South West Southern Thames Welsh… Related Searches: gauging stations

376

Strong P invariance, neutron EDM and minimal Left-Right parity at LHC  

CERN Document Server

In the minimal Left-Right model the choice of left-right symmetry is twofold: either generalized parity $\\mathcal P$ or charge conjugation $\\mathcal C$. In the minimal model with spontaneously broken strict $\\mathcal P$, a large tree-level contribution to strong CP violation can be computed in terms of the spontaneous phase $\\alpha$. Searches for the neutron electric dipole moments then constrain the size of $\\alpha$. Following the latest update on indirect CP violation in the kaon sector, a bound on $W_R$ mass at $20 \\text{ TeV}$ is set. Possible ways out of this bound, either by an additional relaxation mechanism or explicit breaking of $\\mathcal P$ are considered. To this end, the chiral loop of the neutron electric dipole moment at next-to-leading order is re-computed and provides an estimate of the weak contribution. Combining this constraint with other CP violating observables in the kaon sector allows for $M_{W_R} \\gtrsim 3 \\text{ TeV}$. On the other hand, $\\mathcal C$-symmetry is free from such constr...

Maiezza, Alessio

2014-01-01

377

Investigação no contexto brasileiro sobre gestão do conhecimento/aprendizagem/tecnologia de informação: pesquisa realizada na Scientific Electronic Library Online / Research in Brazilian context about knowledge management / learning / information technology: search conducted in Scientific Electronic Library Online  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este artigo investiga a produção científica sobre gestão do conhecimento/aprendizagem/tecnologia de informação por meio de pesquisa na Scientific Electronic Library Online. Primeiro de tudo, foram encontrados 194 artigos que abordavam esses termos separadamente. Num segundo momento, dos 194 artigos [...] foram selecionados 49 que tratavam da gestão do conhecimento organizacional, enfocando o processo e o nível de aprendizagem e utilizando ferramentas de tecnologia de informação. Nestes 49 artigos foi aplicada a classificação de aprendizagem proposta por Pawlowsky, Forslin e Reinhardt (2003), o que possibilitou selecionar oito artigos que apresentavam um maior número de ocorrências relativas à classificação. Por fim, esses oito artigos foram mapeados, constatando-se que a gestão do conhecimento organizacional se refere a um processo de mudança cultural, e que a aprendizagem é um elemento essencial a ser apoiado por ferramentas de tecnologia de informação. Essa constatação possibilitou ainda o entendimento de que (i) a tecnologia de informação pode auxiliar na gestão do conhecimento como um todo (alavancando, conduzindo e direcionando), e (ii) de que é necessário adaptar a tecnologia de informação ao contexto organizacional. Abstract in english This article investigates the scientific production of knowledge management/learning/technology of information, through search carried out in the Scientific Electronic Library Online. Initially, we analyzed 194 articles that discuss the terms individually and selected 49 articles that addressed the [...] management of organizational knowledge, focusing on the process and the level of organizational learning and the use of information technology tools. In these 49 articles, the classification proposed by Pawlowsky et al. (2003) about organizational learning has been applied. This procedure allowed the selection of 8 articles, which had a higher number of incidents relating to the classification. Finally, these 8 articles were mapped and, as a result, it was found that the perception that the organizational knowledge management refers to a process of cultural change and that learning is a key element to be supported by information technology tools has been confirmed. These conclusions allowed the following understandings: i) the possibility of information technology assists in the management of knowledge as a whole (lever, leads and directs), and (ii) the need to adapt the information technology to the organizational context.

Wagner, Igarashi; Deisy Cristina Corrêa, Igarashi; Eleonora Milano Falcão, Vieira; José Leomar, Todesco.

378

Investigação no contexto brasileiro sobre gestão do conhecimento/aprendizagem/tecnologia de informação: pesquisa realizada na Scientific Electronic Library Online Research in Brazilian context about knowledge management / learning / information technology: search conducted in Scientific Electronic Library Online  

Directory of Open Access Journals (Sweden)

Full Text Available Este artigo investiga a produção científica sobre gestão do conhecimento/aprendizagem/tecnologia de informação por meio de pesquisa na Scientific Electronic Library Online. Primeiro de tudo, foram encontrados 194 artigos que abordavam esses termos separadamente. Num segundo momento, dos 194 artigos foram selecionados 49 que tratavam da gestão do conhecimento organizacional, enfocando o processo e o nível de aprendizagem e utilizando ferramentas de tecnologia de informação. Nestes 49 artigos foi aplicada a classificação de aprendizagem proposta por Pawlowsky, Forslin e Reinhardt (2003, o que possibilitou selecionar oito artigos que apresentavam um maior número de ocorrências relativas à classificação. Por fim, esses oito artigos foram mapeados, constatando-se que a gestão do conhecimento organizacional se refere a um processo de mudança cultural, e que a aprendizagem é um elemento essencial a ser apoiado por ferramentas de tecnologia de informação. Essa constatação possibilitou ainda o entendimento de que (i a tecnologia de informação pode auxiliar na gestão do conhecimento como um todo (alavancando, conduzindo e direcionando, e (ii de que é necessário adaptar a tecnologia de informação ao contexto organizacional.This article investigates the scientific production of knowledge management/learning/technology of information, through search carried out in the Scientific Electronic Library Online. Initially, we analyzed 194 articles that discuss the terms individually and selected 49 articles that addressed the management of organizational knowledge, focusing on the process and the level of organizational learning and the use of information technology tools. In these 49 articles, the classification proposed by Pawlowsky et al. (2003 about organizational learning has been applied. This procedure allowed the selection of 8 articles, which had a higher number of incidents relating to the classification. Finally, these 8 articles were mapped and, as a result, it was found that the perception that the organizational knowledge management refers to a process of cultural change and that learning is a key element to be supported by information technology tools has been confirmed. These conclusions allowed the following understandings: i the possibility of information technology assists in the management of knowledge as a whole (lever, leads and directs, and (ii the need to adapt the information technology to the organizational context.

Wagner Igarashi

2008-06-01

379

Numerical study on the splitting of a vapor bubble in the ultrasonic assisted EDM process with the curved tool and workpiece.  

Science.gov (United States)

Electrical discharge machining (EDM) is a powerful and modern method of machining. In the EDM process, a vapor bubble is generated between the tool and the workpiece in the dielectric liquid due to an electrical discharge. In this process dynamic behavior of the vapor bubble affects machining process. Vibration of the tool surface affects bubble behavior and consequently affects material removal rate (MRR). In this paper, dynamic behavior of the vapor bubble in an ultrasonic assisted EDM process after the appearance of the necking phenomenon is investigated. It is noteworthy that necking phenomenon occurs when the bubble takes the shape of an hour-glass. After the appearance of the necking phenomenon, the vapor bubble splits into two parts and two liquid jets are developed on the boundaries of the upper and lower parts of the vapor bubble. The liquid jet developed on the upper part of the bubble impinges to the tool and the liquid jet developed on the lower part of the bubble impinges to the workpiece. These liquid jets cause evacuation of debris from the gap between the tool and the workpiece and also cause erosion of the workpiece and the tool. Curved tool and workpiece affect the shape and the velocity of the liquid jets during splitting of the vapor bubble. In this paper dynamics of the vapor bubble after its splitting near the curved tool and workpiece is investigated in three cases. In the first case surfaces of the tool and the workpiece are flat, in the second case surfaces of the tool and the workpiece are convex and in the third case surfaces of the tool and workpiece are concave. Numerical results show that in the third case, the velocity of liquid jets which are developed on the boundaries of the upper and lower parts of the vapor bubble after its splitting have the highest magnitude and their shape are broader than the other cases. PMID:22784706

Shervani-Tabar, M T; Seyed-Sadjadi, M H; Shabgard, M R

2013-01-01

380

Collaborative searching: social searching, together  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Information Retrieval (IR) is typically an individual pursuit where an individual searcher will engage with a search system, working alone, until their information need is satisfied. Yet in the real world there are many scenarios, both work-related and related to leisure, entertainment or hobbies, where we want to search as part of a team, maybe even a group of only two people. Collaborative Information Retrieval (CIR) refers to technologies which support collaboration in the retrieval proces...

Smeaton, Alan F.

2009-01-01

 
 
 
 
381

Study of the motion of electrons in non polar classical liquids. Measurement of Hall effect and f.i.r. search for low energy traps. Progress report  

International Nuclear Information System (INIS)

Progress is reported on experiments aimed at the measurement of the Hall mobility of injected electrons in classical non polar insulating liquids and the optical absorption associated with electrons captured by shallow traps in the liquefied rare gases. Theoretical work aimed at a better understanding of the trapping kinetics of electrons by SF_6 and O_2 dissolved in rare gas liquids was also carried out. Its conclusion is that the electric field dependence of the trapping probability can be explained, basically without adjustable parameters, by considering the Poole-Frenkel-Schotky ionization of the excited state of the traps. From the analysis of published data on the motion of electrons in liquid ethane it is tentatively concluded that at low temperatures the trapping of electrons in the liquid involves a Jahn-Teller like distortion of a single ethane molecule while at higher temperatures it is necessary to consider a small molecular cluster, possibly made up of 2 molecules

1981-01-01

382

Search for a new charged heavy vector boson decaying to an electron-neutrino pair in p anti-p collisions at s**(1/2) = 1.96 TeV  

Energy Technology Data Exchange (ETDEWEB)

We present results on a search for a heavy charged vector boson, W', decaying to an electron-neutrino pair in p{bar p} collisions at {radical}s = 1.96 TeV using a data sample corresponding to an integrated luminosity of 205 pb{sup -1}. We found no evidence of this decay channel, and set 95% confidence level limits on the production cross section times branching fraction assuming the light neutrino. We also set the limit on the W' boson mass at M{sub W'} > 788 GeV/c{sup 2}, assuming the standard model strength couplings.

Kim, Jieun; /Kyungpook Natl. U.

2005-06-01

383

Bolometric calibration of a super?uid 3He detector for Dark Matter search: direct measurement of the scintillated energy fraction for neutron, electron and muon events  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report on the calibration of a superfluid 3He bolometer developed for the search of non-baryonic Dark Matter. Precise thermometry is achieved by the direct measurement of thermal excitations using Vibrating Wire Resonators (VWRs). The heating pulses for calibration were produced by the direct quantum process of quasiparticle generation by other VWRs present. The bolometric calibration factor is Author manuscript, published in "Nuclear Instr. and Methods in Physics Research, A 574 (2007) 26...

Winkelmann, Clemens; Elbs, Johannes; Bunkov, Yuriy M.; Collin, Eddy; Godfrin, Henri; Krusius, Matti

2007-01-01

384

Development of a 3D touch trigger probe using micro spherical stylus machining by micro-EDM for micro-CMM  

Science.gov (United States)

This study develops a low-cost three-dimensional touch trigger probe for micro-CMM using micro spherical stylus machining by micro-EDM. The tip ball of the stylus, with a diameter smaller than 100 ?m, is made by a micro electro discharge machine with the method of wire electro discharge grinding (WEDG). The current study uses tungsten carbide (WC) as the material for the stylus. Experimental results show that, the tip ball roundness could amount to 2 ?m. Since the tip ball is not easily observable by naked eyes, we designed a micro imaging system to observe the probing in real time. This system is created with modified commercial webcam and microscope. The general design of the touch trigger probe is combined the stylus and suspension structure. When the stylus touches workpiece, it can be determined the time of probe trigger by measuring the motion of suspension structure. The stylus machined by micro-EDM was very fragile and the stylus handle of the tip ball was very thin. Therefore, the stylus handle bends easily that would result in the large measurement error or stylus break when the stylus touched workpiece. In this study we designed a measuring probe using a small chuck and an electrical circuit to measure the probe trigger. When the stylus touches the workpiece, the parallel circuit will switch on immediately and pick up the voltage variation of the resistor. Because the transistor always turns ON, it can avoid the problems of excessive energy and electrical noise.

Chu, Chih-Liang; Chen, Yi-Lin; Tai, Tzu-Yao; Liu, Yun-Hui; Chuang, Cheng-Hsin; Lu, Chin-Tu

2011-08-01

385

Station search  

…than Between AREA Value 1: AREA Value 2: SAAR: Unspecified Greater than Less than Between SAAR Value 1: SAAR Value 2: BFIHOST: Unspecified Greater than Less than Between BFIHOST Value 1: BFIHOST Value 2: PROPWET: Unspecified Greater than Less than Between PROPWET Value 1: PROPWET Value 2: FARL: Unspecified… Related Searches: gauging stations

386

Search Tips  

Science.gov (United States)

... collections: The Health Topics collection contains MedlinePlus Health Topic pages. The External Health Links collection contains links to ... and NIH publications. They appear on MedlinePlus Health Topic pages but they're listed individually in the search ...

387

New Experiment to Measure the Electron Electric Dipole Moment  

Science.gov (United States)

An electron can possess an electric dipole moment (edm) only if time reversal symmetry (T) is violated. No edm of any particle has yet been discovered. CP-violation, equivalent to T-violation by the CPT theorem, does occur in Kaon decays and can be accounted for by the standard model. However, this mechanism leads to an electron edm d(sub e) of the order of 10(exp -38) e cm, whereas the current experimental bound on d(sub e) is about 10(exp -27) e cm. However, well-motivated extensions of the standard model such as supersymmetric theories do predict that de could be as large as the current bound. In addition, CP violation in the early universe is required to explain the preponderance of matter over anti-matter, but the exact mechanism of this CP violation is unclear. For these reasons, we are undertaking a new experimental program to determine de to an improved accuracy of 10(exp -29) e cm. Our experiment will use laser-cooled, trapped Cesium atoms to measure the atomic edm d(sub Cs) that occurs if d(sub e) is not zero. In order to do this, we will measure the energy splitting between the atoms spin states in parallel electric and magnetic fields. The signature of an edm would be a linear dependence of the splitting on the electric field E due to the interaction - d(sub Cs) dot E. Our measurement will be much more sensitive than previous measurements because atoms can be stored in the trap for tens of seconds, allowing for much narrower Zeeman resonance linewidths. Also, our method eliminates the most important systematic errors, proportional to atomic velocity, which have limited previous experiments. In this presentation, we will describe the design of our new apparatus, which is presently under construction. An important feature of our experimental apparatus is that magnetic field noise will be suppressed to a very low value of the order of 1 fT/(Hz)1/2. This requires careful attention to the Johnson noise currents in the chamber, which have not been important in previous experiments. In addition we will present estimates of the limits of the various errors that we expect for our experiment.

Kittle, Melanie

2003-01-01

388

Searching for solvent cavities via electron photodetachment: The ultrafast charge-transfer-to-solvent dynamics of sodide in a series of ether solvents  

International Nuclear Information System (INIS)

It was recently predicted by simulations and confirmed by neutron diffraction experiments that the structure of liquid tetrahydrofuran (THF) contains cavities. The cavities can be quite large and have a net positive electrostatic potential, so they can serve as pre-existing traps for excess electrons created via photodetachment from various solutes. In this paper, we use electron photodetachment via charge-transfer-to-solvent (CTTS) excitation of sodide (Na-) to probe for the presence of pre-existing cavities in a series of ether solvents: THF, diethyl ether, 1,2-dimethoxyethane (DME), and diglyme (DG). We find that electrons photodetached from sodide appear after a time delay with their equilibrium spectrum in all of these solvents, suggesting that the entire series of ethers contains pre-existing solvent cavities. We then use the variation in electron recombination dynamics with CTTS excitation wavelength to probe the nature of the cavities in the different ethers. We find that the cavities that form the deepest electron traps turn on at about the same energy in all four ether solvents investigated, but that the density of cavities is lower in DG and DME than in THF. We also examine the dynamics of the neutral sodium species that remains following CTTS photodetachment of an electron from sodide. We find that the reaction of the initially created gas-phase-like Na atom to form a (Na+,e-) tight-contact pair occurs at essentially the same rate in all four ether solvents, indicating that only local solvent motions and not bulk solvent rearrangements are what is responsible for driving the partial ejection of the remaining Na valence electron.

2009-10-21

389

MiniBooNE oscillation searches  

Energy Technology Data Exchange (ETDEWEB)

The range of oscillation analyses being pursued by the MiniBooNE collaboration is described. Focus is given to the various searches for electron neutrino appearance, but the disappearance of muon neutrinos and the appearance search for electron anti-neutrinos are covered as well.

Brice, Stephen J.

2008-01-01

390

Search for a heavy particle decaying into an electron and a muon with the ATLAS detector in ?s = 7 TeV pp collisions at the LHC  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This Letter presents the first search for a heavy particle decaying into an e\\mu final state in sqrt(s)=7 TeV pp collisions at the LHC. The data were recorded by the ATLAS detector during 2010 and correspond to a total integrated luminosity of 35/pb. No excess above the Standard Model background expectation is observed. Exclusions at 95% confidence level are placed on two representative models. In an R-parity violating supersymmetric model, tau sneutrinos with a mass below 0.75 TeV are exclud...

2011-01-01

391

Search for a Heavy Particle Decaying into an Electron and a Muon with the ATLAS Detector in ?s=7??TeV pp collisions at the LHC  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This Letter presents the first search for a heavy particle decaying into an e±?? final state in ?s=7??TeV pp collisions at the LHC. The data were recorded by the ATLAS detector during 2010 and correspond to a total integrated luminosity of 35??pb-1. No excess above the standard model background expectation is observed. Exclusions at 95% confidence level are placed on two representative models. In an R-parity violating supersymmetric model, tau sneutrinos with a mass below 0.75 T...

2011-01-01

392

Search for a Heavy Particle Decaying into an Electron and a Muon with the ATLAS Detector in root s=7 TeV pp collisions at the LHC  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This Letter presents the first search for a heavy particle decaying into an e(+/-)mu(-/+) final state in root s = 7 TeV pp collisions at the LHC. The data were recorded by the ATLAS detector during 2010 and correspond to a total integrated luminosity of 35 pb(-1). No excess above the standard model background expectation is observed. Exclusions at 95% confidence level are placed on two representative models. In an R-parity violating supersymmetric model, tau sneutrinos with a mass below 0.75 ...

2011-01-01

393

Search for $\  

CERN Document Server

We present the results of a search for nu_mu ? nu_e oscillations in the NOMAD experiment at Cern. The experiment looked for the appearance of nu_e in a predominantly nu_mu wide-band neutrino beam at the CERN SPS. No evidence for oscillations was found. The 90% confidence limits obtained are Delta m^2 ~ 10 eV^2.

Astier, Pierre; Baldisseri, Alberto; Baldo-Ceolin, Massimilla; Banner, M; Bassompierre, Gabriel; Benslama, K; Besson, N; Bird, I; Blumenfeld, B; Bobisut, F; Bouchez, J; Boyd, S; Bueno, A G; Bunyatov, S A; Camilleri, L L; Cardini, A; Cattaneo, Paolo Walter; Cavasinni, V; Cervera-Villanueva, A; Challis, R C; Chukanov, A; Collazuol, G; Conforto, G; Conta, C; Contalbrigo, M; Cousins, R D; Daniels, D; De Santo, A; Degaudenzi, H M; Del Prete, T; Di Lella, L; Dignan, T; Dumarchez, J; Feldman, G J; Ferrari, A; Ferrari, R; Ferrère, D; Flaminio, Vincenzo; Fraternali, M; Gaillard, J M; Gangler, E; Geiser, A; Geppert, D; Gibin, D; Gninenko, S N; Godley, A; Gosset, J; Gouanère, M; Grant, A; Graziani, G; Guglielmi, A M; Gómez-Cadenas, J J; Gössling, C; Hagner, C; Hernando, J; Hong, T M; Hubbard, D B; Hurst, P; Hyett, N; Iacopini, E; Joseph, C L; Juget, F R; Kent, N; Kirsanov, M M; Klimov, O; Kokkonen, J; Kovzelev, A; Krasnoperov, A V; Kustov, D; La Rotonda, L; Lacaprara, S; Lachaud, C; Lakic, B; Lanza, A; Laveder, M; Letessier-Selvon, A A; Linssen, Lucie; Ljubicic, A; Long, J; Lupi, A; Lévy, J M; Marchionni, A; Martelli, F; Mendiburu, J P; Meyer, J P; Mezzetto, Mauro; Mishra, S R; Moorhead, G F; Méchain, X; Naumov, D V; Nefedov, Yu A; Nguyen-Mau, C; Nédélec, P; Orestano, D; Pastore, F; Peak, L S; Pennacchio, E; Pessard, H; Petti, R; Placci, A; Polesello, G; Pollmann, D; Polyarush, A Yu; Popov, B; Poulsen, C; Rebuffi, L; Renò, R; Rico, J; Riemann, P; Roda, C; Rubbia, André; Salvatore, F; Schahmaneche, K; Schmidt, B; Schmidt, T; Sconza, A; Sevior, M E; Shih, D; Sillou, D; Soler, F J P; Sozzi, G; Steele, D; Stiegler, U; Stipcevic, M; Stolarczyk, T; Tareb-Reyes, M; Taylor, G N; Tereshchenko, V V; Toropin, A N; Touchard, A M; Tovey, Stuart N; Tran, M T; Tsesmelis, E; Ulrichs, J; Vacavant, L; Valdata-Nappi, M; Valuev, V Yu; Vannucci, François; Varvell, K E; Veltri, M; Vercesi, V; Vidal-Sitjes, G; Vieira, J M; Vinogradova, T G; Weber, F V; Weisse, T; Wilson, F F; Winton, L J; Yabsley, B D; Zaccone, Henri; Zuber, K; Zuccon, P; do Couto e Silva, E

2003-01-01

394

Anomalon search  

International Nuclear Information System (INIS)

The results of an anomalon search using about three thousand projectile fragments produced by interaction in an emulsion of Fe nuclei of 1.9A GeV are presented. The mean free path of the fragments show a behaviour compatible with normal m.f.p. values of their components. Special care was devoted to investigating if there is a sample of fragments, with common features, which may be responsible for an ''anomalon'' effect. (orig.)

1985-05-06

395

Flushing Ring for EDM  

Science.gov (United States)

Removing debris more quickly lowers cutting time. Operation, cutting oil and pressurized air supplied to ring placed around workpiece. Air forces oil through small holes and agitates oil as it flows over workpiece. High flow rate and agitation dislodge and remove debris. Electrical discharge removes material from workpiece faster.

Earwood, L.

1985-01-01

396

CP Violation at Electron-Positron Colliders  

CERN Document Server

A detailed, model-independent study of CP violation at present and future electron-positron colliders is reported. Firstly, we investigate CP violation effects in $W$ boson and $t$ quark pair production in $e^+e^-$ annihilation and in two-photon fusion at a next $e^+e^-$ linear collider, where Compton-backscattered laser light off the electrons or positrons are employed as a powerful polarized photon source. Secondly, noting that there do not exist any direct measurements for the tau-lepton electric dipole moment (EDM), we address the importance of performing its direct measurements at $e^+e^-$ collisions off the Z-boson pole at TRISTAN, LEPII and CLEOII. We present a rough comparison of the potential of these experiments in the $\\tau$ EDM measurements. Finally, we report on our recent works for probing CP violation in the semileptonic decays of the tau lepton, which involve two different intermediate resonances with large ratios of widths to masses, and which can be most efficiently identified at the planned...

Baek, M S; Hagiwara, K

1997-01-01

397

Electronics Lab  

Science.gov (United States)

This Web site offers a one-stop shop for electronic projects with images, circuits with full descriptions, schematics and diagrams for printed circuit boards (PCBs), integrated circuits, and homemade electronic devices. This site supports an active electronics hobbyist community with free electronics articles, a blog, tutorials, question and answer area, design tips and hints, and an online electronics market with no registration required that allows people to buy and sell electronic parts and devices. This is a good site to search while the old soldering iron is heating up for electronics components, testing equipment, electronic kits, and detailed schematics and diagrams for almost any kind of electronic project including: amplifier, audio and noise, MIDI, counter, radio, simulators, sensors, measurement, temperature detectors, timing and timers, and video.

2009-08-05

398

Search for high mass resonances decaying into electron-positron pairs in proton-proton collisions at ?(s)=7 TeV with the ATLAS detector  

International Nuclear Information System (INIS)

The Standard Model of particle physics was developed to describe the fundamental particles, which form matter, and their interactions via the strong, electromagnetic and weak force. Although most measurements are described with high accuracy, some observations indicate that the Standard Model is incomplete. Numerous extensions were developed to solve these limitations. Several of these extensions predict heavy resonances, so-called Z' bosons, that can decay into an electron positron pair. The particle accelerator Large Hadron Collider (LHC) at CERN in Switzerland was built to collide protons at unprecedented center-of-mass energies, namely 7 TeV in 2011. With the data set recorded in 2011 by the ATLAS detector, a large multi-purpose detector located at the LHC, the electron positron pair mass spectrum was measured up to high masses in the TeV range. The properties of electrons and the probability that other particles are mis-identified as electrons were studied in detail. Using the obtained information, a sophisticated Standard Model expectation was derived with data-driven methods and Monte Carlo simulations. In the comparison of the measurement with the expectation, no significant deviations from the Standard Model expectations were observed. Therefore exclusion limits for several Standard Model extensions were calculated. For example, Sequential Standard Model (SSM) Z' bosons with masses below 2.10 TeV were excluded with 95% Confidence Level (C.L.).

2013-01-01

399

Search for high mass resonances decaying into electron-positron pairs in proton-proton collisions at {radical}(s)=7 TeV with the ATLAS detector  

Energy Technology Data Exchange (ETDEWEB)

The Standard Model of particle physics was developed to describe the fundamental particles, which form matter, and their interactions via the strong, electromagnetic and weak force. Although most measurements are described with high accuracy, some observations indicate that the Standard Model is incomplete. Numerous extensions were developed to solve these limitations. Several of these extensions predict heavy resonances, so-called Z' bosons, that can decay into an electron positron pair. The particle accelerator Large Hadron Collider (LHC) at CERN in Switzerland was built to collide protons at unprecedented center-of-mass energies, namely 7 TeV in 2011. With the data set recorded in 2011 by the ATLAS detector, a large multi-purpose detector located at the LHC, the electron positron pair mass spectrum was measured up to high masses in the TeV range. The properties of electrons and the probability that other particles are mis-identified as electrons were studied in detail. Using the obtained information, a sophisticated Standard Model expectation was derived with data-driven methods and Monte Carlo simulations. In the comparison of the measurement with the expectation, no significant deviations from the Standard Model expectations were observed. Therefore exclusion limits for several Standard Model extensions were calculated. For example, Sequential Standard Model (SSM) Z' bosons with masses below 2.10 TeV were excluded with 95% Confidence Level (C.L.).

Goeringer, Christian

2013-04-25

400

Selection Search on Meta Search Engine  

Directory of Open Access Journals (Sweden)

Full Text Available Existing meta search engine uses identical approach in terms of use of search engines for retrieval of link. They basically send request for links on fixed number of search engines and retrieve results and display aggregate result on screen by eliminating duplicates. In existing meta search engines there is no availability of user choice facility. There is a need to have selection dynamically. This paper discusses the need of dynamic selection of search engine in a meta search engine and discusses a model, which allows user to select search engines. Then, the meta search engine will send request to selected search engines and will generate aggregate result at last.

Mr. Biraj Patel

2013-08-01

 
 
 
 
401

Monophoton search  

CERN Document Server

We present a search for ADD, Branon large extra dimensions and dark matter pair-production with a final state of $\\gamma$ + missing transverse energy in pp collisions at $\\sqrt{s