Science.gov

Sample records for beam pick-up based

  1. PAL-XFEL cavity beam position monitor pick-up design and beam test

    NASA Astrophysics Data System (ADS)

    Lee, Sojeong; Park, Young Jung; Kim, Changbum; Kim, Seung Hwan; Shin, Dong Cheol; Han, Jang-Hui; Ko, In Soo

    2016-08-01

    As an X-ray Free Electron Laser, PAL-XFEL is about to start beam commissioning. X-band cavity beam position monitor (BPM) is used in the PAL-XFEL undulator beam line. Prototypes of cavity BPM pick-up were designed and fabricated to test the RF characteristics. Also, the beam test of a cavity BPM pick-up was done in the Injector Test Facility (ITF). In the beam test, the raw signal properties of the cavity BPM pick-up were measured at a 200 pC bunch charge. According to the RF test and beam test results, the prototype cavity BPM pick-up design was confirmed to meet the requirements of the PAL-XFEL cavity BPM system.

  2. Pick-Up and Kicker Electrodes for the CR

    SciTech Connect

    Peschke, C.; Nolden, F.; Thorndahl, L.

    2006-03-20

    The collector ring (CR) of the proposed GSI project FAIR includes a fast stochastic cooling system for exotic nuclei and antiprotons. To reach a good signal to noise ratio of the pick-up even with a low number of particles, a novel pick-up and kicker electrode system based on slotlines is presented. The sensitivity and noise properties of electrode models are calculated. These are compared with other types of electrodes. Different options for signal processing and layout of a pick-up or kicker with many electrodes for different beam velocities are discussed.

  3. Picking up the pieces.

    PubMed

    Metcalfe, Sarah

    2014-11-01

    The idea of managing patients who have experienced unimaginable horror or suffering can be very daunting. As general practitioners (GPs) we are often the first port of call for people after a significant event or, alternatively, become involved when the patient emerges from the tertiary care system. Part of our role is to help 'pick up the pieces', whether the effects have been predominantly physical, psychological or a combination of both. Sometimes the person before you is fragmented, the pieces so fragile and far flung, that putting them back together seems an impossible task. PMID:25551866

  4. Slow-wave synchronous pick-up and kicker

    SciTech Connect

    DiMassa, G.

    1988-01-01

    Slow-wave synchronous pick-up (PU) and Kicker (K) are proposed for the stochastic cooling of bunched beams in RHIC. A corrugated waveguide is used to support a slow wave that is synchronous with the beam.

  5. Type-I superconductor pick-up coil in superconducting quantum interference device-based ultra-low field nuclear magnetic resonance

    SciTech Connect

    Hwang, Seong-min Kim, Kiwoong; Kyu Yu, Kwon; Lee, Seong-Joo; Hyun Shim, Jeong; Körber, Rainer; Burghoff, Martin

    2014-02-10

    In ultra-low field nuclear magnetic resonance (ULF-NMR) with strong prepolarization field (B{sub p}), type-II superconducting pick-up coils may be vulnerable to flux pinning from the strong B{sub p}. Pick-up coils made of NbTi, Nb, and Pb were evaluated in terms of acquired NMR signal quality. The type-II pick-up coils showed degraded signals above 61 mT maximum exposure, while the Pb pick-up coil exhibited no such degradation. Furthermore, a negative counter pulse following a strong B{sub p} was shown to follow magnetic hysteresis loop to unpin the trapped flux in the type-II pick-up coil and restore the NMR signal.

  6. Pick-up ions at Pluto

    NASA Astrophysics Data System (ADS)

    Kecskemety, K.; Cravens, T. E.

    1993-04-01

    Methane molecules escaping from Pluto's atmosphere are ionized, and the resulting ions are picked up by the solar wind. The mass loading associated with this ion pick-up can produce a cometlike interaction of the solar wind with Pluto. Heavy ion gyroradii are as large as a half million km in the weak interplanetary magnetic field that exists at 30 AU, which is about an order of magnitude larger than the size of the 'interaction region'. We have calculated velocity space distributions of pick-up ions using numerically determined ion trajectories. The predicted pick-up ion fluxes are high enough to be detectable by standard charged particle detectors as far upstream of Pluto as 10 exp 6 km.

  7. Pick-up ions at Pluto

    NASA Technical Reports Server (NTRS)

    Kecskemety, K.; Cravens, T. E.

    1993-01-01

    Methane molecules escaping from Pluto's atmosphere are ionized, and the resulting ions are picked up by the solar wind. The mass loading associated with this ion pick-up can produce a cometlike interaction of the solar wind with Pluto. Heavy ion gyroradii are as large as a half million km in the weak interplanetary magnetic field that exists at 30 AU, which is about an order of magnitude larger than the size of the 'interaction region'. We have calculated velocity space distributions of pick-up ions using numerically determined ion trajectories. The predicted pick-up ion fluxes are high enough to be detectable by standard charged particle detectors as far upstream of Pluto as 10 exp 6 km.

  8. Pick-up and drop transfer of diamond nanosheets.

    PubMed

    Seshan, V; Island, J O; van Leeuwen, R; Venstra, W J; Schneider, B H; Janssens, S D; Haenen, K; Sudhölter, E J R; de Smet, L C P M; van der Zant, H S J; Steele, G A; Castellanos-Gomez, A

    2015-03-27

    Nanocrystalline diamond (NCD) is a promising material for electronic and mechanical micro- and nanodevices. Here we introduce a versatile pick-up and drop technique that makes it possible to investigate the electrical, optical and mechanical properties of as-grown NCD films. Using this technique, NCD nanosheets, as thin as 55 nm, can be picked-up from a growth substrate and positioned on another substrate. As a proof of concept, electronic devices and mechanical resonators are fabricated and their properties are characterized. In addition, the versatility of the method is further explored by transferring NCD nanosheets onto an optical fiber, which allows measuring its optical absorption. Finally, we show that NCD nanosheets can also be transferred onto two-dimensional crystals, such as MoS2, to fabricate heterostructures. Pick-up and drop transfer enables the fabrication of a variety of NCD-based devices without requiring lithography or wet processing. PMID:25742057

  9. Collision free pick up and movement of large objects

    SciTech Connect

    Drotning, W.D.; McKee, G.R.

    1998-08-01

    An automated system is described for the sensor-based precision docking and manipulation of large objects. Past work in the remote handling of large nuclear waste containers is extensible to the problems associated with the handling of large objects such as coils of flat steel in industry. Computer vision and ultrasonic proximity sensing as described here are used to control the precision docking of large objects, and swing damped motion control of overhead cranes is used to control the position of the pick up device and suspended payload during movement. Real-time sensor processing and model-based control are used to accurately position payloads.

  10. Advanced Petroleum-Based Fuels - Diesel Emissions Project (APBF-DEC): 2,000-Hour Performance of a NOx Adsorber Catalyst and Diesel Particle Filter System for a Medium-Duty, Pick-Up Diesel Engine Platform; Final Report

    SciTech Connect

    Not Available

    2007-03-01

    Presents the results of a 2,000-hour test of an emissions control system consisting of a nitrogen oxides adsorber catalyst in combination with a diesel particle filter, advanced fuels, and advanced engine controls in an SUV/pick-up truck vehicle platform.

  11. "Micro-robots" pick up a glass bead

    SciTech Connect

    2011-01-01

    "Micro-robots", which are really collections of particles animated by magnetic fields, pick up a glass bead and move it around the screen. Each movement is precisely controlled. The "asters" were designed by Alexey Snezkho and Igor Aronson at Argonne National Laboratory. Video courtesy Nature Materials. Read the full story at http://go.usa.gov/KAT

  12. Plasma wave, magnetic field and energetic ion observations in the ion pick-up region of Comet Giacobini-Zinner

    NASA Astrophysics Data System (ADS)

    Richardson, I. G.; Cowley, S. W. H.; Wenzel, K.-P.; Scarf, F. L.; Smith, E. J.; Tsurutani, B. T.; Sanderson, T. R.; Hynds, R. J.

    Simultaneous plasma wave, magnetic field, and energetic ion observations made by the ICE spacecraft in the extended ion pick-up region surrounding comet Giacobini-Zinner are examined to determine the conditions under which two characteristic wave emissions, electrostatic waves at a few kHz, and electromagnetic waves at a few tens of Hz, are generated. The data are consistent with the view that the kHz electrostatic emissions result from an instability of the pick-up photoelectron 'beam' produced when the angle alpha between the magnetic field and the solar wind velocity vector is less than about 60 deg, while the behavior of the tens of Hz electromagnetic waves suggests that they are generated by the pick-up ion 'ring' which is present when alpha exceeds about 60 deg.

  13. Design of a slim-type optical pick-up actuator using PMN-PT bimorphs

    NASA Astrophysics Data System (ADS)

    Ko, Byeongsik; Jung, Jung-Sub; Lee, Seung-Yop

    2006-12-01

    In this paper, a new optical pick-up actuator is proposed using PMN-PT (lead magnesium niobate-lead titanate) bimorphs for slim and small form factor optical disk drives. We suggest a novel structure enabling both tracking and focusing motions by changing the moving directions of the two parallel bimorphs. A cymbal-type flextensional structure is used as a displacement amplifier in order to meet the stroke requirement for optical pick-up actuators. We have performed the theoretical analyses for the bimorph actuator and displacement amplifier to predict the resultant force and displacement. The proposed actuator based on PMN-PT bimorphs and displacement amplifier has been manufactured, and the experimental results are compared to the analytical predictions. Experimental results agree well with the analytical predictions, showing that the cymbal structure amplifies the displacement twice and the focusing stroke is 52 µm at 10 V.

  14. Development of a tri-axial optical accelerometer using two DVD pick-up heads

    NASA Astrophysics Data System (ADS)

    Chu, Chih-Liang; Liao, Hong-Wei

    2008-12-01

    This study develops a low-cost, highly-sensitive, three-dimensional optical accelerometer in which the seismic mass comprises four rectangular blocks attached to the ends of a cross-form aluminum structure suspended on four thin steel strips. It is shown through ANSYS finite element (FE) simulations that the thin-strip suspension system restricts the seismic mass to just three degrees of motional freedom, namely one translational motion in the vertical direction and two rotational motions. These displacements are detected using two novel optical sensors based on commercial DVD optical pick-up heads. When the accelerometer experiences a vibrational force, the relative motion between the seismic mass and the base results in a change in the distribution of the reflected light spots on the surfaces of the four-quadrant photodetectors within the two pick-up heads. The resulting changes in the output voltage signals of the two pick-up heads are then used to calculate the corresponding acceleration of the base. The experimental results indicate that the resonance frequencies of the accelerometer in the X, Y and Z-axis directions are 130.51 Hz, 130.63 Hz and 130.90 Hz, respectively. Meanwhile, the sensitivities of the accelerometer in the X, Y and Z-axis directions are 21.28 V/g, 22.94 V/g and 22.75 V/g, respectively.

  15. Energetic cometary ion flows in the pick-up region of Comet Giacobini-Zinner

    NASA Astrophysics Data System (ADS)

    Richardson, I. G.; Cowley, S. W. H.; Hynds, R. J.; Daly, P. W.; Sanderson, T. R.; Wenzel, K.-P.

    The properties of energetic water-group ions in the extended pick-up region surrounding comet Giacobini-Zinner are examined using three-dimensional 65-95-keV ion observations from the EPAS instrument on the ICE spacecraft. The ion distribution is inferred to retain a significant ring-beam anisotropy beyond about 400,000 km from the comet though effects of partial scattering are also present. Closer to the comet, the ions are found to be isotropic, or nearly so, in the solar wind frame due to increased scattering by MHD waves.

  16. Lymph node pick up by separate stations: Option or necessity

    PubMed Central

    Morgagni, Paolo; Nanni, Oriana; Carretta, Elisa; Altini, Mattia; Saragoni, Luca; Falcini, Fabio; Garcea, Domenico

    2015-01-01

    AIM: To evaluate whether lymph node pick up by separate stations could be an indicator of patients submitted to appropriate surgical treatment. METHODS: One thousand two hundred and three consecutive gastric cancer patients submitted to radical resection in 7 general hospitals and for whom no information was available on the extension of lymphatic dissection were included in this retrospective study. RESULTS: Patients were divided into 2 groups: group A, where the stomach specimen was directly formalin-fixed and sent to the pathologist, and group B, where lymph nodes were picked up after surgery and fixed for separate stations. Sixty-two point three percent of group A patients showed < 16 retrieved lymph nodes compared to 19.4% of group B (P < 0.0001). Group B (separate stations) patients had significantly higher survival rates than those in group A [46.1 mo (95%CI: 36.5-56.0) vs 27.7 mo (95%CI: 21.3-31.9); P = 0.0001], independently of T or N stage. In multivariate analysis, group A also showed a higher risk of death than group B (HR = 1.24; 95%CI: 1.05-1.46). CONCLUSION: Separate lymphatic station dissection increases the number of retrieved nodes, leads to better tumor staging, and permits verification of the surgical dissection. The number of dissected stations could potentially be used as an index to evaluate the quality of treatment received. PMID:26015852

  17. Electric field by pick-up ions and electrons

    NASA Astrophysics Data System (ADS)

    Yamauchi, Masatoshi; Behar, Etienne; Nilsson, Hans; Holmstrom, Mats

    2016-04-01

    Observations by the Rosetta Plasma Consortium (RPC) showed increasing distortion of the solar wind flow as Rosetta approached the Sun, i.e., as the density of the newly born ions increased. This indicates azimuthal momentum transfer from the solar wind to the newly born ions because they are displaced by the solar wind electric field up to the ion gyroradius this the solar wind velocity, and conservation of the momentum (center of the mass) makes the solar wind to azimuthally shift by "counter action" of these pick-up ion motions. To understand this azimuthal momentum transfer, it is inevitable to model the electric field by the displacement of these pick-up ions and electrons. Although the E×B drift does not make charge separation when the scale size is larger than the ion gyroradius, ions and electrons move in the opposite direction to each other within the short distance up to a gyroradius, and therefore, the charge separation occurs. Thus, the newly-ionized neutrals (ion-electron pairs) create the electric field in the opposite (shielding) direction to the solar wind electric field (like the ionopause of Venus and Mars). However, such a newly induced "shielding" electric field will simultaneously be weakened by the solar wind electrons because the solar wind is also moved by this shielding electric field to reduce it, in the same way as the plasma oscillation (time scale of about 10‑4 s). In other words, the solar wind tries to maintain the solar wind electric field as far as the momentum allows. These two opposite effects must be combined when modelling the azimuthal electric field, and resultant ion/electron motions within a gyroradius, like the case for ROSETTA. Furthermore, the effect of the induced electric field by the pick-up ions and electrons will be different when the newly born ions are created as the result of photo-ionization and of the charge exchange because the electron effect is different between them. In the presentation, we model the

  18. Pick-Up Oxygen Ion Loss at Mars

    NASA Astrophysics Data System (ADS)

    Curry, S.; Liemohn, M. W.; Fang, X.; Ma, Y.

    2010-12-01

    The Mars pick-up ion transport model has been developed to study the relative role of kinetic processes on ion transport through near-Mars space. Mars does not have a strong, intrinsic dipole magnetic field and consequently the solar wind directly interacts with the dayside upper atmosphere causing particles to be stripped away from the atmosphere. The Mars Pickup Ion Model model calculates the detailed ion velocity space distribution (VSD) through a background magnetic and electric field model at specific locations. The main objective of this work is to robustly probe the sources of planetary ion escape from Mars' upper atmosphere. We explore three sources of ions: photoionization, charge exchange collisions, and impact ionization. Our results illustrate distinct differences in the velocity space distributions from the different source mechanisms, which can be used to decipher Mars ion observations according to their source population. Because the VSDs are non-Maxwellian and reveal asymmetirc, non-gyrotropic features, our simulation can uniquely investigate these distributions without using the Maxwellian assumptions of current MHD models. Our results help to further examine quantify the physical processes and source locations for specific VSD fine-structure features, and to put this into the context of real and virtual observations of escaping planetary ions.

  19. Application of FIB with micro pick-up to microstructural study of irradiated SiC/SiC composites.

    PubMed

    Ozawa, Kazumi; Kondo, Sosuke; Kishimoto, Hirotatsu; Kohyama, Akira

    2004-01-01

    The combination of focused ion beam (FIB) micro-processing and the lift-out technique using the micro pick-up system was applied to the preparation of TEM specimens of irradiated SiC/SiC composites. The deformation caused by microstructural evolution was observed in the pyrolitic carbon interphase, and several helium bubbles and cavities were detected in the CVI matrix. PMID:15582959

  20. Axial Vibration Characteristics Considering a Moving Pick-Up Unit for the Flexible Optical Disk System

    NASA Astrophysics Data System (ADS)

    Jo, Jun Hyeon; Rhim, Yoon Chul

    2011-09-01

    The axial vibration characteristics of the flexible optical disk are investigated experimentally considering the pick-up window and the geometry of a moving pick-up. The axial runout of the disk is measured by using a laser displacement sensor along the four perpendicular radial directions. Measurements are conducted with respect to the shapes of pick-up faces, which have different radius of curvatures, as well as to the positions of the moving pick-up. A flat stabilizer with damping orifices is used in the experiment and the disk is rotated at 8,000, 10,000, and 12,000 rpm. The axial runouts and the displacements of the disk are measured for 6 different shaped pick-ups. The smallest axial runout of 10 µm, which is well manageable for the current optical disk drive technology, is obtained when we use the curved pick-up with curvatures of 400 mm in the direction of disk rotation.

  1. Anticipatory Adjustments to Being Picked Up in Infancy

    PubMed Central

    Reddy, Vasudevi; Markova, Gabriela; Wallot, Sebastian

    2013-01-01

    Anticipation of the actions of others is often used as a measure of action understanding in infancy. In contrast to studies of action understanding which set infants up as observers of actions directed elsewhere, in the present study we explored anticipatory postural adjustments made by infants to one of the most common adult actions directed to them – picking them up. We observed infant behavioural changes and recorded their postural shifts on a pressure mat in three phases: (i) a prior Chat phase, (ii) from the onset of Approach of the mother’s arms, and (iii) from the onset of Contact. In Study 1, eighteen 3-month-old infants showed systematic global postural changes during Approach and Contact, but not during Chat. There was an increase in specific adjustments of the arms (widening or raising) and legs (stiffening and extending or tucking up) during Approach and a decrease in thrashing/general movements during Contact. Shifts in postural stability were evident immediately after onset of Approach and more slowly after Contact, with no regular shifts during Chat. In Study 2 we followed ten infants at 2, 3 and 4 months of age. Anticipatory behavioural adjustments during Approach were present at all ages, but with greater differentiation from a prior Chat phase only at 3 and 4 months. Global postural shifts were also more phase differentiated in older infants. Moreover, there was significantly greater gaze to the mother’s hands during Approach at 4 months. Early anticipatory adjustments to being picked up suggest that infants’ awareness of actions directed to the self may occur earlier than of those directed elsewhere, and thus enable infants’ active participation in joint actions from early in life. PMID:23840324

  2. On the stability of pick-up ion ring distributions in the outer heliosheath

    SciTech Connect

    Summerlin, Errol J.; Viñas, Adolfo F.; Moore, Thomas E.; Christian, Eric R.; Cooper, John F. E-mail: adolfo.figueroa-vinas-1@nasa.gov E-mail: eric.r.christian@nasa.gov

    2014-10-01

    The 'secondary energetic neutral atom (ENA)' hypothesis for the ribbon feature observed by the Interstellar Boundary Explorer (IBEX) posits that the neutral component of the solar wind continues beyond the heliopause and charge exchanges with interstellar ions in the Outer Heliosheath (OHS). This creates pick-up ions that gyrate about the draped interstellar magnetic field (ISMF) lines at pitch angles near 90° on the locus where the ISMF lies tangential to the heliopause and perpendicular to the heliocentric radial direction. This location closely coincides with the location of the ribbon feature according to the prevailing inferences of the ISMF orientation and draping. The locally gyrating ions undergo additional charge exchange and escape as free-flying neutral atoms, many of which travel back toward the inner solar system and are imaged by IBEX as a ribbon tracing out the locus described above. For this mechanism to succeed, the pick-up ions must diffuse in pitch angle slowly enough to permit secondary charge exchange before their pitch angle distribution substantially broadens away from 90°. Previous work using linear Vlasov dispersion analysis of parallel propagating waves has suggested that the ring distribution in the OHS is highly unstable, which, if true, would make the secondary ENA hypothesis incapable of rendering the observed ribbon. In this paper, we extend this earlier work to more realistic ring distribution functions. We find that, at the low densities necessary to produce the observed IBEX ribbon via the secondary ENA hypothesis, growth rates are highly sensitive to the temperature of the beam and that even very modest temperatures of the ring beam corresponding to beam widths of <1° are sufficient to damp the self-generated waves associated with the ring beam. Thus, at least from the perspective of linear Vlasov dispersion analysis of parallel propagating waves, there is no reason to expect that the ring distributions necessary to produce the

  3. On the inlet vortex system. [preventing jet engine damage caused by debris pick-up

    NASA Technical Reports Server (NTRS)

    Bissinger, N. C.; Braun, G. W.

    1974-01-01

    The flow field of a jet engine with an inlet vortex, which can pick up heavy debris from the ground and damage the engine, was simulated in a small water tunnel by means of the hydrogen bubble technique. It was found that the known engine inlet vortex is accompained by a vortex system, consisting of two inlet vortices (the ground based and the trailing one), secondary vortices, and ground vortices. Simulation of the ground effect by an inlet image proved that the inlet vortex feeds on free stream vorticity and can exist without the presence of a ground boundary layer. The structural form of the inlet vortex system was explained by a simple potential flow model, which showed the number, location, and the importance of the stagnation points. A retractable horizontal screen or an up-tilt of the engine is suggested as countermeasure against debris ingestion.

  4. Experience with the 1.7 GHz Schottky Pick-ups in the Tevatron

    SciTech Connect

    Jansson, A.; Lebrun, P.; Pasquinelli, R.; /Fermilab

    2004-07-01

    During a 2003 shutdown, new high-frequency Schottky pick-ups were installed in the Tevatron. These devices operate at 1.7 GHz (harmonic 36000 of the revolution frequency) and can in principle be used to measure tunes, chromaticities, momentum spread and transverse emittances of individual bunches. Only the transverse signal is used, as the longitudinal is dominated by coherent signal. The default mode of operation during a store is to sequentially acquire and analyze frequency data from different sets of bunches in the machine. This function is performed by an Open Access Client (OAC) written in Java/C++, running in the background. The resulting fit parameters are datalogged and can also be plotted in ''real time'' during the store. With an alternative setup, data from select bunches can be acquired continuously during the entire ramp (and squeeze), for analysis off-line. This paper describes the evolution, current status and performance of the acquisition and analysis software, and presents measurements with comparison to predictions and other measurement techniques. One example of such a measurement is the variation of beam-beam tune shift as a function of intensity and bunch position within a train.

  5. Not Just Being Lifted: Infants are Sensitive to Delay During a Pick-Up Routine.

    PubMed

    Fantasia, Valentina; Markova, Gabriela; Fasulo, Alessandra; Costall, Alan; Reddy, Vasudevi

    2015-01-01

    In the present study we observed whether infants show online adjustments to the mother's incipient action by looking at their sensitivity to changes as the pick-up unfolded. Twenty-three 3-month-old infants and their mothers were observed in the lab, where mothers were instructed (1) to pick-up their infants as they usually did (normal pick-up), and then (2) to delay the pick-up for 6 s after placing their hands on the infants' waist (delayed pick-up). In both Normal and Delayed conditions infant's body tension, affective displays and gaze shifts were coded during three phases: Approach, Contact, and Lift. Additionally, a measure of infants' head support in terms of head lag at the beginning and end of Lift was computed. Results showed that during normal pick-up infants tensed up their body during the Approach phase and increased their tension during contact, maintaining it through Lift; their head was also supported and in line with their body during Lift. When the pick-up was delayed, infants also tensed their body during Approach, yet this tension did not increase during the Contact phase and was significantly lower at Lift. Their head support was also lower in the Delayed condition and they shifted their gazes away from their mothers' face more often than in the Normal condition. These results suggest that infants are sensitive to changes of the timing of the pick-up sequence, which in turn may have affected their contribution to the interaction. PMID:26834674

  6. Not Just Being Lifted: Infants are Sensitive to Delay During a Pick-Up Routine

    PubMed Central

    Fantasia, Valentina; Markova, Gabriela; Fasulo, Alessandra; Costall, Alan; Reddy, Vasudevi

    2016-01-01

    In the present study we observed whether infants show online adjustments to the mother’s incipient action by looking at their sensitivity to changes as the pick-up unfolded. Twenty-three 3-month-old infants and their mothers were observed in the lab, where mothers were instructed (1) to pick-up their infants as they usually did (normal pick-up), and then (2) to delay the pick-up for 6 s after placing their hands on the infants’ waist (delayed pick-up). In both Normal and Delayed conditions infant’s body tension, affective displays and gaze shifts were coded during three phases: Approach, Contact, and Lift. Additionally, a measure of infants’ head support in terms of head lag at the beginning and end of Lift was computed. Results showed that during normal pick-up infants tensed up their body during the Approach phase and increased their tension during contact, maintaining it through Lift; their head was also supported and in line with their body during Lift. When the pick-up was delayed, infants also tensed their body during Approach, yet this tension did not increase during the Contact phase and was significantly lower at Lift. Their head support was also lower in the Delayed condition and they shifted their gazes away from their mothers’ face more often than in the Normal condition. These results suggest that infants are sensitive to changes of the timing of the pick-up sequence, which in turn may have affected their contribution to the interaction. PMID:26834674

  7. Pick-up ion energization at the termination shock

    SciTech Connect

    Gary, S Peter; Winske, Dan; Wu, Pin; Schwadron, N A

    2009-01-01

    One-dimensional hybrid simulations are used to investigate how pickup ions are energized at the perpendicular termination shock. Contrary to previous models based on pickup ion energy gain by repeated crossings of the shock front (shock surfing) or due to a reforming shock front, the present simulations show that pickup ion energy gain involves a gyro-phasedependent interaction with the inhomogeneous motional electric field at the shock. The process operates at all relative concentrations of pickup ion density.

  8. Skills and offensive tactics used in pick-up basketball games.

    PubMed

    Wang, Jianyu; Liu, Wenhao; Moffit, Jeffrey

    2009-10-01

    The purpose of this study was to describe skills and offensive tactics frequently used in pick-up basketball games. 65 participants were recruited from public basketball courts. An observational instrument was developed to analyze the performances of pick-up games. Participants' performances were videotaped and coded. Results indicated that the passing skills most frequently observed in the games were chest pass, overhead pass, and bounce pass. For dribbling, crossover dribble and change-of-pace dribble were frequently observed. Jump shot, set shot, and layup were also frequently used. The offensive tactics frequently used included drive, cut, and set screen. The study may be beneficial for helping young people prepare to play pick-up basketball games. PMID:20038001

  9. Detection of singly ionized energetic lunar pick-up ions upstream of earth's bow shock

    NASA Technical Reports Server (NTRS)

    Hilchenbach, M.; Hovestadt, D.; Klecker, B.; Moebius, E.

    1992-01-01

    Singly ionized suprathermal ions upstream of the earth's bow shock have been detected by using the time-of-flight spectrometer SULEICA on the AMPTE/IRM satellite. The data were collected between August and December 1985. The flux of the ions in the mass range between 23 and 37 amu is highly anisotropic towards the earth. The ions are observed with a period of about 29 days around new moon (+/- 3 days). The correlation of the energy of the ions with the solar wind speed and the interplanetary magnetic field orientation indicates the relation to the pick-up process. We conclude that the source of these pick-up ions is the moon. We argue that due to the impinging solar wind, atoms are sputtered off the lunar surface, ionized in the sputtering process or by ensuing photoionization and picked up by the solar wind.

  10. Detection of interstellar pick-up hydrogen in the solar system

    NASA Technical Reports Server (NTRS)

    Gloeckler, G.; Geiss, J.; Balsiger, H.; Fisk, L. A.; Galvin, A. B.; Ipavich, F. M.; Ogilvie, K. W.; Von Steiger, R.; Wilken, B.

    1993-01-01

    Interstellar hydrogen ionized primarily by the solar wind has been detected by the Solar Wind Ion Composition Spectrometer instrument on the Ulysses spacecraft at a distance of 4.8 AUs from the sun. This 'pick-up' hydrogen is identified by its distinct velocity distribution function, which drops abruptly at twice the local solar wind speed. From the measured fluxes of pick-up protons and singly charged helium, the number densities of neutral hydrogen and helium in the distant regions of the solar system are estimated to be 0.077 +/- 0.015 and 0.013 +/- 0.003 per cu cm, respectively.

  11. INTERSTELLAR PICK-UP IONS OBSERVED BETWEEN 11 AND 22 AU BY NEW HORIZONS

    SciTech Connect

    Randol, B. M.; McComas, D. J.; Schwadron, N. A.

    2013-05-10

    We report new observations by the Solar Wind Around Pluto instrument on the New Horizons spacecraft, which measures energy per charge (E/q) spectra of solar wind and interstellar pick-up ions (PUIs) between 11 AU and 22 AU from the Sun. The data provide an unprecedented look at PUIs as there have been very few measurements of PUIs beyond 10 AU. We analyzed the PUI part of the spectra by comparing them to the classic Vasyliunas and Siscoe PUI model. Our analysis indicates that PUIs are usually well-described by this distribution. We derive parameters relevant to PUI studies, such as the ionization rate normalized to 1 AU. Our result for the average ionization rate between 11 and 12 AU agrees with an independently derived average value found during the same time. Later, we find a general increase in the ionization rate, which is consistent with the increase in solar activity. We also calculate the PUI thermal pressure, which appears to be roughly consistent with previous results. Through fitting of the solar wind proton peaks in our spectra, we derive solar wind thermal pressures. Based on our analysis, we predict a ratio of PUI thermal pressure to solar wind thermal pressure just inside the termination shock to be between 100 and >1000.

  12. Hands-free device control using sound picked up in the ear canal

    NASA Astrophysics Data System (ADS)

    Chhatpar, Siddharth R.; Ngia, Lester; Vlach, Chris; Lin, Dong; Birkhimer, Craig; Juneja, Amit; Pruthi, Tarun; Hoffman, Orin; Lewis, Tristan

    2008-04-01

    Hands-free control of unmanned ground vehicles is essential for soldiers, bomb disposal squads, and first responders. Having their hands free for other equipment and tasks allows them to be safer and more mobile. Currently, the most successful hands-free control devices are speech-command based. However, these devices use external microphones, and in field environments, e.g., war zones and fire sites, their performance suffers because of loud ambient noise: typically above 90dBA. This paper describes the development of technology using the ear as an output source that can provide excellent command recognition accuracy even in noisy environments. Instead of picking up speech radiating from the mouth, this technology detects speech transmitted internally through the ear canal. Discreet tongue movements also create air pressure changes within the ear canal, and can be used for stealth control. A patented earpiece was developed with a microphone pointed into the ear canal that captures these signals generated by tongue movements and speech. The signals are transmitted from the earpiece to an Ultra-Mobile Personal Computer (UMPC) through a wired connection. The UMPC processes the signals and utilizes them for device control. The processing can include command recognition, ambient noise cancellation, acoustic echo cancellation, and speech equalization. Successful control of an iRobot PackBot has been demonstrated with both speech (13 discrete commands) and tongue (5 discrete commands) signals. In preliminary tests, command recognition accuracy was 95% with speech control and 85% with tongue control.

  13. What Skills and Tactics Are Needed to Play Adult Pick-Up Basketball Games?

    ERIC Educational Resources Information Center

    Wang, Jianyu; Liu, Wenhao; Moffit, Jeffrey

    2010-01-01

    The purpose of this study was to examine skill levels and performance patterns of regular players of pick-up basketball games. By a survey, 65 participants were identified as regular players and participated in the study. An observational instrument used to analyze game performance of the participants was developed and both content and construct…

  14. 41 CFR 102-41.230 - May SASPs pick up or store donated drug paraphernalia in their distribution centers?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false May SASPs pick up or store donated drug paraphernalia in their distribution centers? 102-41.230 Section 102-41.230 Public... SASPs pick up or store donated drug paraphernalia in their distribution centers? No, you must...

  15. 41 CFR 102-41.230 - May SASPs pick up or store donated drug paraphernalia in their distribution centers?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false May SASPs pick up or store donated drug paraphernalia in their distribution centers? 102-41.230 Section 102-41.230 Public... SASPs pick up or store donated drug paraphernalia in their distribution centers? No, you must...

  16. 41 CFR 102-41.230 - May SASPs pick up or store donated drug paraphernalia in their distribution centers?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false May SASPs pick up or store donated drug paraphernalia in their distribution centers? 102-41.230 Section 102-41.230 Public... SASPs pick up or store donated drug paraphernalia in their distribution centers? No, you must...

  17. 41 CFR 102-41.230 - May SASPs pick up or store donated drug paraphernalia in their distribution centers?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false May SASPs pick up or store donated drug paraphernalia in their distribution centers? 102-41.230 Section 102-41.230 Public... SASPs pick up or store donated drug paraphernalia in their distribution centers? No, you must...

  18. 41 CFR 102-41.230 - May SASPs pick up or store donated drug paraphernalia in their distribution centers?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false May SASPs pick up or store donated drug paraphernalia in their distribution centers? 102-41.230 Section 102-41.230 Public... SASPs pick up or store donated drug paraphernalia in their distribution centers? No, you must...

  19. Origin of the O(+) pick-up ions in the hehiosphere

    NASA Technical Reports Server (NTRS)

    Geiss, J.; Gloeckler, G.; Mall, U.

    1994-01-01

    The main sources for the ions in the interplanetary medium are the solar wind and the interstellar gas intruding into the heliosphere. Other sources, i.e. comets and planets can, however, contribute significantly locally. We present approximate expressions for deriving fluxes of pick-up ions originating from local neutral gas sources. Since the Io-torus is thought to be a relatively strong emitter of fast atoms, particular O and S, we used the O(+) data obtained by SWICS-Ulysses as a function of distance from Jupiter, both in and out-off the ecliptic plane in order to recognize a possible contribution of the Ionian source to the measured O(+). We find that - except for a very limited zone near the Jovian magnetosphere - the contribution of the Io-torus to the O(+) fluxes is minor, thus confirming our previous results on the pick-up H(+), He(+), N(+), O(+), and Ne(+) fluxes of interstellar origin.

  20. Strong Seasonal Variation of Martian Pick-up Ions and Reflected Ions

    NASA Astrophysics Data System (ADS)

    Yamauchi, Masatoshi; Hara, Takuya; Lundin, Rickard; Dubinin, Edik; Fedorov, Andrei; Frahm, Rudy; Futaana, Yoshifumi; Holmstrom, Mats; Barabash, Stas

    2015-04-01

    Mars Express (MEX) has operated for more than 10 years in the environment of Mars, providing solar wind ion observations by the Analyzer of Space Plasmas and Energetic Atoms (ASPERA-3) experiment's ion mass analyzer (IMA). In the region just outside the bow shock of Mars, IMA frequently observes ring-like distributed ions that include both pick-up ions of exospheric origin and reflected solar wind by the bow shock (Yamauchi et al., 2012). Although there are some restrictions imposed when using the IMA measurements, the length and quality of the IMA data is sufficient to statistically diagnose the seasonal and solar cycle variation. According to this long-term observation, the observation probability of the ring-like distributed ions outside the bow shock with certain intensity strongly depends on the season, i.e., the flux of these ions varies by nearly one order of magnitude every two years. A careful examination reveals that the variation of pick-up ions is locked to the distance from the Sun rather than the tilt angle of the rotation axis. This indicates that the planetary scale variation of solar UV has a drastic effect on the formation of the pick-up ions. Solar cycle effects are not distinguishable partly because they are masked by the seasonal effects and partly because MEX and IMA are optimum for such observations due to the instrumental limitations (FOV and energy range) and the lack of the magnetometer experiment on the Mars Express spacecraft

  1. A non-dominated sorting genetic algorithm for a bi-objective pick-up and delivery problem

    NASA Astrophysics Data System (ADS)

    Velasco, N.; Dejax, P.; Guéret, C.; Prins, C.

    2012-03-01

    Some companies must transport their personnel within facilities. This is especially the case for oil companies that use helicopters to transport engineers, technicians and assistant personnel from platform to platform. This operation has the potential to become expensive if the transportation routes are not correctly planned and provide a bad quality of service. Here this issue is modelled as a pick-up and delivery problem where a set of transportation requests should be scheduled in routes, minimizing the total transportation cost while the most urgent requests are satisfied by priority. To solve the problem, a method based on a Non-dominated Sorting Genetic Algorithm (NSGA-II) is proposed. This algorithm is tested on both randomly generated and real instances provided by a petroleum company. The results show that the proposed algorithm improves the best-known solutions.

  2. Kinetic modeling of Europa's neutral atmosphere and pick-up ions

    NASA Astrophysics Data System (ADS)

    Tenishev, V.; Rubin, M.; Borovikov, D.; Jia, X.; Combi, M. R.; Gombosi, T. I.

    2013-12-01

    Europa was the highest priority outer planet exploration target in the 2007 NASA Science Plan, the 2006 Solar System Exploration Roadmap, and the 2003 planetary sciences Decadal Survey. The in-depth exploration of the plasma environment of Jupiter's moon Europa and investigation of its interaction with moon's surface and atmosphere remains a central objective of any proposed Europa Jupiter System Mission. The neutral species in Europa's atmosphere are mostly provided by ion sputtering of the water ice surface. Energetic ions and electrons from the Jovian magnetosphere produce molecular oxygen O2, the dominant species in Europa's atmosphere. Very close to the moon's surface the probability for collisional interaction between the species is close to the limit for a surface bound exosphere. The main loss mechanisms for neutrals are electron impact ionization, photoionization, as well as escape when neutral particles leave Europa's Hill sphere at roughly 8.7 Europa radii. The neutral and plasma environment of Europa are a tightly coupled system. A detailed study of this system requires coupled models of both the plasma and neutral environment. In this study we use coupled state-of-the-art computer models developed at the University of Michigan. In particular we include the BATSRUS MHD code of the Space Weather Modeling Framework (SWMF) and the Adaptive Mesh Particle Simulator (AMPS) model based on the DSMC method that both have well proven heritage in numerous space applications. In this investigation we calculate the plasma distribution in the vicinity of Europa at different locations along its orbit. The energetic ion flux derived from these calculations is used for simulation of the neutral particle sputtering that form Europa's atmosphere. The subsequent ionization of these neutral particles is the source of the pick-up ions. Populations of the neutrals and ions are calculated by tracing trajectories of the individual particles with accounting for both Europa

  3. Phase space diffusion and anisotropic pick-up ion distributions in the solar wind: an injection study

    NASA Astrophysics Data System (ADS)

    Chalov, S. V.; Fahr, H. J.

    1998-07-01

    Pick-up ions are produced all over the interplanetary space by ionization of neutral interstellar atoms. Over the last decade it was generally expected that after pick-up these ions quickly are isotropized in the velocity space comoving with the solar wind by strong pitch-angle scattering, though not assimilating to the thermodynamic state of solar wind ions. Recent studies of pick-up ion data obtained with plasma analyzers on AMPTE and ULYSSES have, however, revealed that during extended time periods substantially anisotropic distributions prevail. In this paper we want to improve the understanding of the evolutionary behaviour of pick-up ions in interplanetary phase space by an pick-up ion injection study taking into account all relevant diffusion terms describing pitch angle scattering, adiabatic cooling, drifts and energy diffusion. For particles injected at 1 AU the resulting distribution function stays substantially anisotropic up to distances of the order of 6 AU, unless increased isotropic turbulence levels and non-dissipative wave spectra are considered. The average bulk velocity of pick-up ions within this distance range is smaller than the solar wind velocity by factors of between 0.6 and 1.0. Pick-ups are shown to substantially become spread out from that solar wind parcel into which they were originally injected. Derivations of interstellar gas parameters using pick-up ion flux data can only be dared with additional care in the interpretation. As a consequence the location of the LISM helium cone axis and the LISM helium temperature are faked in the associated He(+) pick-up ion flux pattern.

  4. Stellar wind interaction and pick-up ion escape of the Kepler-11 "super-Earths"

    NASA Astrophysics Data System (ADS)

    Kislyakova, K. G.; Johnstone, C. P.; Odert, P.; Erkaev, N. V.; Lammer, H.; Lüftinger, T.; Holmström, M.; Khodachenko, M. L.; Güdel, M.

    2014-02-01

    Aims: We study the interactions between stellar winds and the extended hydrogen-dominated upper atmospheres of planets. We estimate the resulting escape of planetary pick-up ions from the five "super-Earths" in the compact Kepler-11 system and compare the escape rates with the efficiency of the thermal escape of neutral hydrogen atoms. Methods: Assuming the stellar wind of Kepler-11 is similar to the solar wind, we use a polytropic 1D hydrodynamic wind model to estimate the wind properties at the planetary orbits. We apply a direct simulation Monte Carlo model to model the hydrogen coronae and the stellar wind plasma interaction around Kepler-11b-f within a realistic expected heating efficiency range of 15-40%. The same model is used to estimate the ion pick-up escape from the XUV heated and hydrodynamically extended upper atmospheres of Kepler-11b-f. From the interaction model, we study the influence of possible magnetic moments, calculate the charge exchange and photoionization production rates of planetary ions, and estimate the loss rates of pick-up H+ ions for all five planets. We compare the results between the five "super-Earths" and the thermal escape rates of the neutral planetary hydrogen atoms. Results: Our results show that a huge neutral hydrogen corona is formed around the planet for all Kepler-11b-f exoplanets. The non-symmetric form of the corona changes from planet to planet and is defined mostly by radiation pressure and gravitational effects. Non-thermal escape rates of pick-up ionized hydrogen atoms for Kepler-11 "super-Earths" vary between ~6.4 × 1030 s-1 and ~4.1 × 1031 s-1, depending on the planet's orbital location and assumed heating efficiency. These values correspond to non-thermal mass loss rates of ~1.07 × 107 g s-1 and ~6.8 × 107 g s-1 respectively, which is a few percent of the thermal escape rates.

  5. Stellar wind interaction and pick-up ion escape of the Kepler-11 "super-Earths"

    NASA Astrophysics Data System (ADS)

    Kislyakova, Kristina; Johnstone, Colin; Odert, Petra; Erkaev, Nikolai; Lammer, Helmut; Lüftinger, Theresa; Holmstöm, Mats; Khodachenko, Maxim; Güdel, Manuel

    2014-05-01

    We present the results of modeling of the interactions between stellar wind and the extended hydrogen-dominated upper atmospheres of planets and estimate the resulting escape of planetary pick-up ions from the 5 «super-Earths» in the compact Kepler-11 system. We compare the escape rates with the efficiency of the thermal escape of neutral hydrogen atoms. Assuming the stellar wind of Kepler-11 is similar to the solar wind, we used a polytropic 1D hydrodynamic wind model to estimate the wind properties at the planetary orbits. We applied a Direct Simulation Monte Carlo Model to model the hydrogen coronae and the stellar wind plasma interaction around Kepler-11b-f planets within a realistic expected heating efficiency range of 15-40%. The same model was used to estimate the ion pick-up escape from the XUV heated and hydrodynamically extended upper atmospheres of Kepler-11b-f. Modeling clarifies the influence of possible magnetic moments on escape processes and allows to estimate the charge exchange and photoionization production rates of planetary ions as well as the loss rates of pick-up H+ ions for all five planets. This study presents also the comparison of the results between the five 'super-Earths' and in a more general sense also with the thermal escape rates of the neutral planetary hydrogen atoms. Our results show that for all Kepler-11b-f exoplanets, a huge neutral hydrogen corona is formed around the planet. The non-symmetric form of the corona changes from planet to planet and is defined mostly by radiation pressure, charge-exchange and gravitational effects. According to our estimates, nonthermal escape rates of pick-up ionized hydrogen atoms for Kepler-11 «super-Earths» vary between ~ 6.4 × 1030 s-1 and ~ 4.1 × 1031 s-1 depending on the planet's orbital location and assumed heating efficiency. These values correspond to non-thermal mass loss rates of ~ 1.07 × 107 g·s-1 and ~ 6.8 × 107 g·s-1 respectively, which is a few percent of the thermal

  6. Comparison of picked-up protons and water group ions upstream of Comet Halley's bow shock

    NASA Technical Reports Server (NTRS)

    Neugebauer, M.; Coates, A. J.; Neubauer, F. M.

    1990-01-01

    The similarities and differences between the picked-up cometary protons and water-group (WG) ions upstream of the bow shock of Comet Halley are examined using measurements obtained by the ion mass spectrometer and plasma analyzer experiments on board Giotto. It was found that the dependencies of the pitch angle and the energy diffusion rates of the cometary protons and WG ions on the ion densities and on the angle alpha between the interplanetary field and the solar wind velocity vector were very different. This finding could not be explained in terms of presently available theories and models.

  7. Seasonal variation of Martian pick-up ions: Evidence of breathing exosphere

    NASA Astrophysics Data System (ADS)

    Yamauchi, M.; Hara, T.; Lundin, R.; Dubinin, E.; Fedorov, A.; Sauvaud, J.-A.; Frahm, R. A.; Ramstad, R.; Futaana, Y.; Holmstrom, M.; Barabash, S.

    2015-12-01

    The Mars Express (MEX) Ion Mass Analyser (IMA) found that the detection rate of the ring-like distribution of protons in the solar wind outside of the bow shock to be quite different between Mars orbital summer (around perihelion) and orbital winter (around aphelion) for four Martian years, while the north-south asymmetry is much smaller than the perihelion-aphelion difference. Further analyses using eight years of MEX/IMA solar wind data between 2005 and 2012 has revealed that the detection frequency of the pick-up ions originating from newly ionized exospheric hydrogen with certain flux strongly correlates with the Sun-Mars distance, which changes approximately every two years. Variation due to the solar cycle phase is not distinguishable partly because this effect is masked by the seasonal variation under the MEX capability of plasma measurements. This finding indicates that the variation in solar UV has a major effect on the formation of the pick-up ions, but this is not the only controlling factor.

  8. Loss of Water from Saturn's E-Ring Through Ion Pick-Up

    NASA Technical Reports Server (NTRS)

    Leisner, J. S.; Russell, C. T.; Dougherty, M. K.; Blanco-Cano, X.; Smith, E. J.; Tsurutani, B. T.

    2005-01-01

    One of the possible loss processes for Saturn s E-ring is ionization followed by acceleration by the electric field associated with the corotating magnetized plasma. It is possible to determine if this process is occurring by detecting electromagnetic waves at the gyrofrequency of water group ions. If the energy the particle gains in this pick-up process is sufficiently great, the picked up ions will generate ion cyclotron waves. Pioneer 11 and Voyager 1 both observed intervals of such waves associated with water group ions during their passes through Saturn s E-ring. Presently the magnetometer onboard the Cassini spacecraft is also seeing water group ion cyclotron oscillations. The Cassini data allow the spatial and temporal behavior of the waves to be mapped in ways not possible during the previous flybys. Analyses of these waves allow us to study the rate of mass loading and its latitudinal and local time variation. In conjunction with previous data, we can then determine the variation as the inclination of the ring to the Sun changes, in accordance with Saturn's seasons. These waves may be the clue to how Saturn powers its magnetosphere as the newly born ions could be the driver for the radial motion of the plasma and to how the E-ring may play the equivalent role to that of Io in the jovian magnetosphere.

  9. A contactless methodology of picking up micro-particles from rigid surfaces by acoustic radiation force

    NASA Astrophysics Data System (ADS)

    Jia, Kun; Yang, Keji; Fan, Zongwei; Ju, Bing-Feng

    2012-01-01

    Controlled movement and pick up of small object from a rigid surface is a primary challenge in many applications. In this paper, a contactless methodology of picking up micro-particles within deionized water from rigid surfaces by acoustic radiation force is presented. In order to achieve this, an acoustic radiation force was generated by 1.75 MHz transducers. A custom built setup facilitates the optimization of the sound field by varying the parameters such as sound source size and source position. The three-dimensional pressure distributions are measured and its relative sound field is also characterized accordingly. The standing wave field has been formed and it is mainly composed of two obliquely incident plane waves and their reflectors. We demonstrated the gripping and positioning of silica beads, SiO2, and aluminum micro-particles of 100 μm to 500 μm in size with this method using acoustic radiation force. The acoustic radiation force generated is well controlled, contactless, and in the tens of nano-Newton range which allowed us to manipulate relative big micro objects such as MEMS components as well as moving objects such as living cells. The proposed method provided an alternative form of contactless operating environment with scalable dimensions suitable for the manipulating of small objects. This permits high-throughput processing and reduction in time required for MEMS assembling, cell biomechanics, and biotechnology applications.

  10. Comparison of high altitude pick-up ions at Mars and Venus

    NASA Astrophysics Data System (ADS)

    Curry, S.; Luhmann, J. G.; Liemohn, M. W.; McEnulty, T.; Wang, Y.; Johnson, B. C.; Fang, X.; Ma, Y.

    2013-12-01

    In the absence of a dipole magnetic field, the atmospheres of Mars and Venus are especially susceptible to scavenging, but each planet has unique physical processes controlling their planetary ion distributions and atmospheric escape. We present a comparison of virtual detections of atmospheric pick-up ions at Mars and Venus using the combined results from magnetohydrodynamic and test particle simulations. Pick-up ions form when the solar wind directly interacts with the neutral atmosphere, causing the newly created ions to be accelerated by the background convective electric field. In these weakly magnetized environments, heavy ion species can have gyroradii on the planetary scale size. In order to address the role of individual ion motion, this study will provide velocity space distributions and individual particle traces for different species at each planet in multiple locations. It will also quantify the influence of the remnant crustal magnetic fields at Mars and stronger gravitational field at Venus. Additionally, results for different solar conditions will be presented and compared with data observations in order to better describe the evolution of atmospheric volatiles at Mars and Venus.

  11. Sealed vacuum canister and method for pick-up and containment of material

    DOEpatents

    Stoutenburgh, R.R.

    1996-02-13

    A vacuum canister is described including a housing with a sealed vacuum chamber having a predetermined vacuum pressure therein and a valve having a first port for fluid communication with the vacuum chamber and a second port for receiving at least one of a fluid and a particulate material. The valve is operable between a first position to seal the vacuum chamber and retain the predetermined vacuum within the vacuum chamber, and a second position to access the vacuum chamber to permit vacuum fluid flow through the valve from the second port into the vacuum chamber. The vacuum canister, in the operation to pick up material with the valve in the second position, when the second port is located adjacent at least one of a fluid and a particulate material, is effective to displace through the valve at least one of a fluid and a particulate material into the housing. The vacuum canister is desirably suitable for picking up and containing hazardous material such as radioactive material, in which the vacuum canister includes a protective layer of lead having a predetermined thickness that is effective to shield radiation emitted from the radioactive material contained within the housing. Advantageously, the vacuum canister includes a vacuum means for establishing a predetermined vacuum pressure within the vacuum chamber. 6 figs.

  12. Sealed vacuum canister and method for pick-up and containment of material

    DOEpatents

    Stoutenburgh, Roger R.

    1996-01-01

    A vacuum canister including a housing with a sealed vacuum chamber having a predetermined vacuum pressure therein and a valve having a first port for fluid communication with the vacuum chamber and a second port for receiving at least one of a fluid and a particulate material. The valve is operable between a first position to seal the vacuum chamber and retain the predetermined vacuum within the vacuum chamber, and a second position to access the vacuum chamber to permit vacuum fluid flow through the valve from the second port into the vacuum chamber. In operation of the vacuum canister to pick up material with the valve in the second position, when the second port is located adjacent at least one of a fluid and a particulate material, is effective to displace through the valve at least one of a fluid and a particulate material into the housing. The vacuum canister is desirably suitable for picking up and containing hazardous material such as radioactive material, in which the vacuum canister includes a protective layer of lead having a predetermined thickness that is effective to shield radiation emitted from the radioactive material contained within the housing. Advantageously, the vacuum canister includes a vacuum means for establishing a predetermined vacuum pressure within the vacuum chamber.

  13. 41 CFR 102-36.135 - How much time do we have to pick up excess personal property that has been approved for transfer?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... to pick up excess personal property that has been approved for transfer? 102-36.135 Section 102-36... pick up excess personal property that has been approved for transfer? Normally, you have 15 calendar days from the date of GSA allocation to pick up the excess personal property for transfer, and you...

  14. Titan's atmospheric sputtering and neutral torus produced by magnetospheric and pick-up ions

    NASA Astrophysics Data System (ADS)

    Michael, M.; Smith, H. T.; Johnson, R. E.; Shematovich, V.; Leblanc, F.; Ledvina, S.; Luhmann, J. H.

    As Titan does not possess an intrinsic magnetic field, Kronian magnetospheric ions can penetrate Titan's exobase as can locally produced pick-up ions (e.g. Shematovich et al. 2003). This can cause atmospheric loss and heating of the exobase region. Penetration by slowed and deflected magnetospheric ions and by the pick-up ions is described here using a 3-D Monte Carlo model (Michael et al. 2004). The incident ions can lead to the production of fast neutrals that collide with other atmospheric neutrals producing the ejection of both atomic and molecular nitrogen and heating. The recently calculated dissociation cross sections of N2 are used in the present model (Tully and Johnson 2002). The incident flux of slowed magnetospheric N+ ions and pick-up C2H5+ ions is estimated from the work of Brecht et al. (2000). These ions, which have energies less than 1.2 keV, were shown to be more efficient in ejecting material from Titan's atmosphere than the non-deflected co-rotating ions used earlier (Lammer et al. 1993). The loss rates are comparable or larger than those produced by photo-dissociation. Exobse heating rates are given and the loss rates of N and N2 are then used as a source of nitrogen for the Titan neutral torus. If atmospheric sputtering is important this torus will contain both atomic and molecular nitrogen and, therefore, will provide a distributed source of both atomic and molecular nitrogen ions that will be readily detected by Cassini (Smith et al. 2004) Acknowledgment: This work is supported by NASA's Planetary Atmospheres Program and by the CAPS-Cassini Instrument. Brecht, S.H., J.G. Luhmann, and D.J. Larson, J. Geophys. Res., 105, 13119, 2000. Lammer, H., and S.J. Bauer,. Planet. Space Sci., 41, 657, 1993. Shematovich, V.I.,et al, J. Geophys. Res., 108, 5086, 10.1029/2003JE002096, 2003. Michael, M. et al., submitted, Icarus, 2004. Smith, H.T., et al., Titan Aeronomy Workshop, Paris, January 7-9, 2004. Tully, C., R.E. Johnson, J. Chem. Phys. 117, 6556

  15. A Monolithic Confocal Laser Coupler For an Optical Pick-up

    NASA Astrophysics Data System (ADS)

    Mizuno, Takeshi; Doi, Masato; YoshinobuHiguchi, YoshinobuHiguchi; Taniguchi, Takehiro; NobukataOkano, NobukataOkano; Nakao, Takashi; Narui, Hironobu; Matsuda, Osamu

    1999-04-01

    We propose a novel optical pick-up using a confocal lasercoupler for an optical disk player. The laser coupler consists of aglass window and a monolithic optical element which includes a laserdiode, 8 photodiodes, and a pyramid-shaped prism mirror positionednear the confocal plane which acts as a knife edge and aphoto-coupler. The focusing-error signal is detected using theconfocal knife edge (CKE) method and the tracking-error signal isdetected using the CKE push-pull method. The jitter of Compact Disc(CD) readout was 6.7 ns at a line velocity of 1.2 m/s, and the DCoffsets of the tracking-error signal were sppressed to less than 1/3for a radial lens displacement of ±400 µm compared to theconventional push-pull method.

  16. Fast pick up technique for high quality heterostructures of bilayer graphene and hexagonal boron nitride

    SciTech Connect

    Zomer, P. J. Guimarães, M. H. D.; Brant, J. C.; Tombros, N.; Wees, B. J. van

    2014-07-07

    We present a fast method to fabricate high quality heterostructure devices by picking up crystals of arbitrary sizes. Bilayer graphene is encapsulated with hexagonal boron nitride to demonstrate this approach, showing good electronic quality with mobilities ranging from 17 000 cm{sup 2} V{sup −1} s{sup −1} at room temperature to 49 000 cm{sup 2} V{sup −1} s{sup −1} at 4.2 K, and entering the quantum Hall regime below 0.5 T. This method provides a strong and useful tool for the fabrication of future high quality layered crystal devices.

  17. Escape of Nitrogen from Titan's atmosphere driven by magnetospheric and pick-up ions

    NASA Astrophysics Data System (ADS)

    Michael, M.; Liu, M.; Johnson, R. E.; Luhmann, J. G.; Shematovich, V. I.

    2003-05-01

    The nitrogen rich atmosphere of Titan is a significant source of the neutrals in Saturn's magnetosphere. As Titan does not posses an intrinsic magnetic field, energetic Kronian magnetospheric ions penetrate Titan's atmospheric exobase as can local pick-up ions (e.g. Shematovich et al. 2003). Penetration by energetic ions is described here using a 3-D Monte Carlo model. The incident ions can lead directly or indirectly to the production of fast neutrals that collide with other atmospheric neutrals. This leads to dissociation and the ejection of both atomic and molecular nitrogen. The recently calculated dissociation cross sections of N2 are used in the present model (Tully and Johnson 2002). The incident flux of slowed magentospheric N+ ions and pick-up C2H_5+ ions is estimated from the work of Brecht et al. (2000). These ions of energy less than 1.2 keV are shown to be more efficient in ejecting material from Titan's atmosphere than the higher energy corotating ions described in early estimates (Lammer et al. 1998). This incident flux of ions are used in the model and the results are used as a source of nitrogen for the Saturnian plasma torus. Acknowledgment: This work is supported by NASA:s Planetary Atmospheres Program. References Brecht, S.H., J.G. Luhmann, and D.J. Larson, J. Geophys. Res., 105, 13119, 2000. Lammer, H. W. Stumptner, and S.J. Bauer, Planet. Space Sci., 46, 1207, 1998. Shematovich, V.I., R.E. Johnson, M. Michael and J.G. Luhmann, J. Geophys. Res., in press, 2003. Tully, C., R.E. Johnson, J. Chem. Phys. 117, 6556-6561, 2002.

  18. Generalized Jeans' Escape of Pick-Up Ions in Quasi-Linear Relaxation

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Khazanov, G. V.

    2011-01-01

    Jeans escape is a well-validated formulation of upper atmospheric escape that we have generalized to estimate plasma escape from ionospheres. It involves the computation of the parts of particle velocity space that are unbound by the gravitational potential at the exobase, followed by a calculation of the flux carried by such unbound particles as they escape from the potential well. To generalize this approach for ions, we superposed an electrostatic ambipolar potential and a centrifugal potential, for motions across and along a divergent magnetic field. We then considered how the presence of superthermal electrons, produced by precipitating auroral primary electrons, controls the ambipolar potential. We also showed that the centrifugal potential plays a small role in controlling the mass escape flux from the terrestrial ionosphere. We then applied the transverse ion velocity distribution produced when ions, picked up by supersonic (i.e., auroral) ionospheric convection, relax via quasi-linear diffusion, as estimated for cometary comas [1]. The results provide a theoretical basis for observed ion escape response to electromagnetic and kinetic energy sources. They also suggest that super-sonic but sub-Alfvenic flow, with ion pick-up, is a unique and important regime of ion-neutral coupling, in which plasma wave-particle interactions are driven by ion-neutral collisions at densities for which the collision frequency falls near or below the gyro-frequency. As another possible illustration of this process, the heliopause ribbon discovered by the IBEX mission involves interactions between the solar wind ions and the interstellar neutral gas, in a regime that may be analogous [2].

  19. Endocrinological profile and follicular development in cyclic ewes subjected to repeated ovum pick-up.

    PubMed

    Valasi, I; Theodosiadou, E; Fthenakis, G C; Papanikolaou, T; Deligiannis, C; Kalogiannis, D; Chadio, S; Amiridis, G S

    2013-05-01

    Blood concentrations of progesterone, FSH and oestradiol in Karagouniko ewes subjected to laparoscopic ovum pick-up (OPU) at specific stages of induced oestrous cycle, were measured. Twenty-four cyclic ewes were randomly allocated into four equal groups (A, B, C and D). Oestrus was synchronized with progestagen intravaginal sponges and detected by teaser rams (oestrus: day 0). In group A, during the induced oestrous cycle, OPU was performed on days 4, 9 and 14 (sessions A1, A2 and A3, respectively). In group B and group D, OPU was performed once, on day 9 and 14, respectively. In group C (controls), endoscopic observation of follicular population was performed three times, as in group A. Starting at sponge removal, progesterone was measured in blood samples collected on 22 daily occasions and oestradiol in samples collected on 27 occasions collected at various time-points starting 2h before to 24h after OPU. Follicular populations did not differ among A1, A2, A3 or between C1, C2, C3 and A1, A2, A3 or A1, B, D, respectively. Oocytes of better quality (category '1' or '2') were collected at A3 session compared with A1 (P<0.05). Progesterone concentration and oestrous cycle length did not differ among groups. Decreased oestradiol concentrations followed by FSH increase were recorded 3-5h after OPU. The results confirm the regulatory role of oestradiol on FSH secretion. The quality of collected oocytes was improved in subsequent pick-up sessions in the oestrous cycle. Moreover, OPU at specific stages of the luteal phase of the cycle, even when applied repeatedly, do not affect the normal oestrous cycle length of ewes. PMID:23523233

  20. Influence of applied magnetic field strength and frequency response of pick-up coil on the magnetic barkhausen noise profile

    NASA Astrophysics Data System (ADS)

    Vashista, M.; Moorthy, V.

    2013-11-01

    The influence of applied magnetic field strength and frequency response of the pick-up coil on the shape of Magnetic Barkhausen Noise (MBN) profile have been studied. The low frequency MBN measurements have been carried out using 5 different MBN pick-up coils at two different ranges of applied magnetic field strengths on quenched and tempered (QT) and case-carburised and tempered (CT) 18CrNiMo7 steel bar samples. The MBN pick-up coils have been designed to obtain different frequency response such that the peak frequency response varies from ˜4 kHz to ˜32 kHz and the amplitude of low frequency signals decreases gradually. At lower applied magnetic field strength of ±14,000 A/m, all the pick-up coils produced a single peak MBN profile for both QT and CT sample. However, at higher applied magnetic field strength of ±22,000 A/m, the MBN profile showed two peaks for both QT and CT samples for pick-up coils with peak frequency response up to ˜17 kHz. Also, there is systematic reduction in peak 2 for QT sample and asymmetric reduction in the heights of peak 1 and peak 2 for CT sample with increase in peak frequency response of the pick-up coils. The decreasing sensitivity of pick-up coils with increasing peak frequency response to MBN signal generation is indicated by the gradual reduction in width of MBN profile and height of peak 2 in the QT sample. The drastic reduction in peak 1 as compared to peak 2 in the CT sample shows the effect of decreasing low frequency response of the pick-up coils on lowering skin-depth of MBN signal detection. This study clearly suggests that it is essential to optimise both maximum applied magnetic field strength and frequency response of the MBN pick-up coil for maximising the shape of the MBN profile for appropriate correlation with the magnetisation process and hence the material properties.

  1. The use of gas chromatography for the quantitative determination of micro-amounts of insecticide picked up by mosquitos*

    PubMed Central

    Pennell, J. T.; Miskus, R.; Craig, R.

    1964-01-01

    The test method recommended by the WHO Expert Committee on Insecticides for determining the susceptibility or resistance of adult mosquitos to insecticides has been evaluated quantitatively by the use of gas chromatography to measure the amount of dieldrin picked up by adult Culex quinquefasciatus Say (= C. pipiens fatigans Wiedemann). A strain homozygous for dieldrin-resistance was used to determine the pick-up as a function of time and concentration of dieldrin. The results of experiments using electron-capture detection with gas chromatography suggest that the pick-up is a linear function of the concentration on the paper and also of the time of exposure, even of the 24-hour exposure to the 4.0% dieldrin paper. PMID:14122446

  2. Solar cycle variation of interstellar neutral He, Ne, O density and pick-up ions along the Earth's orbit

    NASA Astrophysics Data System (ADS)

    Sokół, Justyna M.; Bzowski, Maciej; Kubiak, Marzena A.; Möbius, Eberhard

    2016-06-01

    We simulated the modulation of the interstellar neutral (ISN) He, Ne, and O density and pick-up ion (PUI) production rate and count rate along the Earth's orbit over the solar cycle (SC) from 2002 to 2013 to verify if SC-related effects may modify the inferred ecliptic longitude of the ISN inflow direction. We adopted the classical PUI model with isotropic distribution function and adiabatic cooling, modified by time- and heliolatitude-dependent ionization rates and non-zero injection speed of PUIs. We found that the ionization losses have a noticeable effect on the derivation of the ISN inflow longitude based on the Gaussian fit to the crescent and cone peak locations. We conclude that the non-zero radial velocity of the ISN flow and the energy range of the PUI distribution function that is accumulated are of importance for a precise reproduction of the PUI count rate along the Earth orbit. However, the temporal and latitudinal variations of the ionization in the heliosphere, and particularly their variation on the SC time-scale, may significantly modify the shape of PUI cone and crescent and also their peak positions from year to year and thus bias by a few degrees the derived longitude of the ISN gas inflow direction.

  3. OBSERVATIONS OF ISOTROPIC INTERSTELLAR PICK-UP IONS AT 11 AND 17 AU FROM NEW HORIZONS

    SciTech Connect

    Randol, B. M.; McComas, D. J.; Elliott, H. A.; Gosling, J. T.; Schwadron, N. A.

    2012-08-10

    We report new observations by the Solar Wind Around Pluto (SWAP) instrument on the New Horizons spacecraft of an energy-per-charge (E/q) spectrum of interstellar pick-up ions (PUIs) from an unprecedented heliocentric distance of 17 AU. This E/q spectrum is fit well by an isotropic PUI distribution function combined with the detailed response of the SWAP instrument. In contrast to earlier work, we are also able to fit an isotropic PUI model to an E/q spectrum measured by SWAP at 11.3 AU by explicitly including two additional effects. These are (1) the E/q-dependent geometric factor of SWAP, which increases with decreasing E/q owing to effects associated with the post-acceleration of particles exiting the electrostatic analyzer portion of the instrument; and (2) a solar wind distribution, the model spectrum of which contributes significantly to the low-E/q part of the overall model owing, presumably, to secondary particles produced within the instrument.

  4. Mars atmospheric loss and isotopic fractionation by pick-up-ion sputtering and photochemical escape

    NASA Technical Reports Server (NTRS)

    Jakosky, B. M.; Pepin, R. O.; Johnson, R. E.; Fox, J. L.

    1994-01-01

    We examine the effects of loss of constituents of the Martian atmosphere due to sputtering by solar-wind pick-up ions and photochemical escape during the last 3.8 billion years. Sputtering is capable of efficiently removing species from the upper atmosphere to space, including the light noble gases; nitrogen and oxygen are removed by both sputtering ad photochemical processes. Due to diffusive separation (by mass) above the homopause, removal from the top of the atmosphere will fractionate the isotopes of each species, with the lighter isotope being preferentially lost. This allows current measurements of the isotopic ratios to be used as a measure of the atmospheric evolution as integrated over geologic time. For carbon and oxygen, isotopic fractionation is buffered by exchange of atmospheric species with non-atmospheric reservoirs of CO2 and H2O. This allows us to determine the size of the non-atmospheric reservoirs which are capable of mixing with the atmosphere; these reservoirs can be CO2 absorbed in the regolith and/or H2O in the polar ice caps. Such an exchangeable reservoir is required in order to keep the fractionation of the atmospheric gases as low as is observed.

  5. Picking Up the Mantle of "Expert": Assigned Roles, Assertion of Identity, and Peer Recognition within a Programming Class

    ERIC Educational Resources Information Center

    Fields, Deborah; Enyedy, Noel

    2013-01-01

    Changing an established role in a classroom is difficult. It involves constructing a new set of relations within a community. In this article we investigate how students with newly developed interest and experience in programming developed outside the classroom pick up and establish their roles as experts in programming within the classroom…

  6. 77 FR 40385 - Withdrawal of Regulatory Guide 7.3; Procedures for Picking Up and Receiving Packages of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-09

    ... Packaging Requirements for Shipment and Receipt of Radioactive Material,'' which was issued in March 28... Radioactive Material AGENCY: Nuclear Regulatory Commission. ACTION: Notice of withdrawal; correction. SUMMARY... Commission) is withdrawing RG 7.3, ``Procedures for Picking Up and Receiving Packages of Radioactive...

  7. Oocyte recovery by ovum pick up and embryo production in river buffaloes (Bubalus bubalis).

    PubMed

    Manjunatha, B M; Ravindra, J P; Gupta, P S P; Devaraj, M; Nandi, S

    2008-08-01

    Ovum pick up (OPU) was conducted twice a week for 12 weeks in six cycling, non-descriptive (local breed), Indian buffaloes to study the efficiency of OPU on recovery of oocytes for embryo production. OPU was performed using an ultrasound equipment with a 5-MHz transvaginal transducer, a single-lumen, 18-gauge, 55-cm-long needle and a constant vacuum pressure of 110 mmHg. The number and size of follicles were determined before puncture. The recovered oocytes were graded, washed, matured for 24 h and then fertilized with frozen-thawed semen, followed by embryo culture on the oviductal monolayer. The mean number of follicles observed per animal per session did not differ between animals or between puncture sessions. A mean number of 3.62 +/- 0.32 mm follicles were observed, 2.90 +/- 0.15 mm follicles were punctured and 1.21 +/- 0.07 oocytes were recovered per animal per session, with an average recovery rate of 42%. Of the total oocytes recovered, 64% were suitable for in vitro embryo production (grade A + B) whereas 36% were classified to be of grades C + D. A mean number of 0.25 +/- 0.2 transferable embryos was produced in vitro per buffalo per session with a transferable embryo production rate of 32%. In conclusion, this study demonstrated that twice-a-week OPU could be applied repeatedly, without any adverse effects on the follicular growth and oocyte recovery and that recovered oocytes could be used for in vitro embryo production in buffaloes. PMID:18282214

  8. Comparison of ultrasound-guided vs laparoscopic transvaginal ovum pick-up (OPU) in simmental heifers.

    PubMed

    Santl, B; Wenigerkind, H; Schernthaner, W; Mödl, J; Stojkovic, M; Prelle, K; Holtz, W; Brem, G; Wolf, E

    1998-07-01

    Transvaginal ovum pick-up (OPU) offers several advantages over standard embryo transfer procedures. For a systematic comparison of the ultrasound-guided (U-OPU) and the laparoscopic OPU (L-OPU) method, groups of Simmental heifers were subjected to 1 of the 2 OPU-methods for 8 wk (15 sessions) followed by a treatment-free interval of 11 wk and then another 8-wk period of OPU using the alternative method. Parameters that were evaluated included the number of follicles aspirated, number and morphology of recovered cumulus-oocyte complexes (COCs), and developmental capacity of oocytes after in vitro maturation (IVM) and fertilization (IVF). Blood samples were also taken from the donors twice a wk for progesterone measurement. To evaluate effects of long-term OPU on subsequent fertility of donors, all heifers (n = 14) were inseminated during the first natural estrus after the OPU experiment. The proportion of Class I oocytes was significantly (P < 0.001) higher after U-OPU than after L-OPU (38.7% vs 21.0%). Following IVM/IVF, this difference in oocyte quality was reflected by the cleavage rate (U-OPU: 58.1%; L-OPU: 52.1%; P < 0.05) and the rate of development to morulae and blastocysts (U-OPU: 27.1%; L-OPU: 13.9%; P < 0.001). Among other factors, the greater changes in vacuum pressure during L-OPU vs U-OPU might be responsible for the difference in oocyte quality. This problem may be overcome by a more flexible system for regulating the vacuum. Progesterone levels were higher during the L-OPU than the U-OPU periods. Seven donors (50%) were diagnosed pregnant by ultrasonography on Day 28 and by palpation per rectum on Day 42. PMID:10734477

  9. Comparative pick-up ion distributions at Mars and Venus: Consequences for atmospheric deposition and escape

    NASA Astrophysics Data System (ADS)

    Curry, Shannon M.; Luhmann, Janet; Ma, Yingjuan; Liemohn, Michael; Dong, Chuanfei; Hara, Takuya

    2015-09-01

    Without the shielding of a substantial intrinsic dipole magnetic field, the atmospheres of Mars and Venus are particularly susceptible to similar atmospheric ion energization and scavenging processes. However, each planet has different attributes and external conditions controlling its high altitude planetary ion spatial and energy distributions. This paper describes analogous test particle simulations in background MHD fields that allow us to compare the properties and fates, precipitation or escape, of the mainly O+ atmospheric pick-up ions at Mars and Venus. The goal is to illustrate how atmospheric and planetary scales affect the upper atmospheres and space environments of our terrestrial planet neighbors. The results show the expected convection electric field-related hemispheric asymmetries in both precipitation and escape, where the degree of asymmetry at each planet is determined by the planetary scale and local interplanetary field strength. At Venus, the kinetic treatment of O+ reveals a strong nightside source of precipitation while Mars' crustal fields complicate the simple asymmetry in ion precipitation and drive a dayside source of precipitation. The pickup O+ escape pattern at both Venus and Mars exhibits low energy tailward escape, but Mars exhibits a prominent, high energy 'polar plume' feature in the hemisphere of the upward convection electric field while the Venus ion wake shows only a modest poleward concentration. The overall escape is larger at Venus than Mars (2.1 ×1025 and 4.3 ×1024 at solar maximum, respectively), but the efficiency (likelihood) of O+ escaping is 2-3 times higher at Mars. The consequences of these comparisons for pickup ion related atmospheric energy deposition, loss rates, and detection on spacecraft including PVO, VEX, MEX and MAVEN are considered. In particular, both O+ precipitation and escape show electric field controlled asymmetries that grow with energy, while the O+ fluxes and energy spectra at selected spatial

  10. Single-particle strength in neutron-rich 69Cu from the 70Zn(d ,3He)69Cu proton pick-up reaction

    NASA Astrophysics Data System (ADS)

    Morfouace, P.; Franchoo, S.; Sieja, K.; Stefan, I.; de Séréville, N.; Hammache, F.; Assié, M.; Azaiez, F.; Borcea, C.; Borcea, R.; Grassi, L.; Guillot, J.; Le Crom, B.; Lefebvre, L.; Matea, I.; Mengoni, D.; Napoli, D.; Petrone, C.; Stanoiu, M.; Suzuki, D.; Testov, D.

    2016-06-01

    We have performed the 70Zn(d ,3He)69Cu proton pick-up reaction in direct kinematics using a deuteron beam at 27 MeV. The outgoing 3He particles were detected at the focal-plane detection system of an Enge split-pole spectrometer. The excitation-energy spectrum was reconstructed up to 7 MeV and spectroscopic factors were obtained after analysis of the angular distributions in the finite-range distorted-wave Born approximation. The results show three new angular distributions for which the π f7 /2 strength was measured and a lower limit of the centroid is established. State-of-the-art shell-model calculations are performed and predict a π f7 /2 strength that lies too high in energy in comparison to our experimental results.

  11. Long term effect of Ovum Pick-up in buffalo species.

    PubMed

    Neglia, Gianluca; Gasparrini, Bianca; Vecchio, Domenico; Boccia, Lucia; Varricchio, Ettore; Di Palo, Rossella; Zicarelli, Luigi; Campanile, Giuseppe

    2011-02-01

    The aim of this study was to evaluate the effect of an Ovum Pick-up (OPU) treatment carried out for 9 months in buffalo (Bubalus bubalis) species. Eight pluriparous non-lactating buffalo cows underwent OPU for 9 months. Recovered cumulus enclosed oocytes (COCs) were classified and COCs suitable for in vitro embryo production (IVEP) were in vitro matured (IVM), fertilized (IVF) and cultured (IVC) to the blastocyst (Bl) stage. Animals were monitored for a total period of 270 days, but at the summer solstice, follicular turnover decreased and at the 68-day of the trial, we decided to increase the OPU sampling interval from 3-4 to 7 days. It was therefore possible to distinguish two phases: a first phase (18 sessions), during which OPU was carried out twice weekly and a second phase (16 sessions) during which OPU sessions were performed weekly. This reduction did not modify the percentage of good quality COCs, while the incidence of grade D COCs decreased (P<0.01). Furthermore, embryo production was higher in the second phase, either if embryos were calculated on the total recovered COCs (8.3% vs. 21.4%; P<0.01) and on grade A+B COCs (13.0% vs. 32.1%; P<0.01), that supposedly should have given similar blastocyst yield. During the total period of the trial it was possible to distinguish a first period of 6 months (34 sessions) characterized by blastocyst production (0.36 blastocyst/buffalo/session), followed by an unproductive period of 3 months (12 sessions), during which embryos were not produced. During the first 6 months a higher (P<0.01) number of follicles (5.06 vs. 3.71), small follicles (3.38 vs. 2.07), total COCs (2.58 vs. 1.56) and good quality (A+B) COCs (1.51 vs. 0.94) per subject/session were recorded compared to the last 3 months. No Blastocyst were produced during the second period, even if the percentage of grade A+B COCs was similar to that recorded during the first period. In conclusion, buffalo cows submitted to repeated OPU sampling for a 9-month

  12. The 4.8 GHz LHC Schottky pick-up system

    SciTech Connect

    Caspers, Fritz; Jimenez, Jose Miguel; Jones, Rhodri Owain; Kroyer, Tom; Vuitton, Christophe; Hamerla, Timothy W.; Jansson, Andreas; Misek, Joel; Pasquinelli, Ralph J.; Seifrid, Peter; Sun, Ding; /Fermilab

    2007-06-01

    The LHC Schottky observation system is based on traveling wave type high sensitivity pickup structures operating at 4.8 GHz. The choice of the structure and operating frequency is driven by the demanding LHC impedance requirements, where very low impedance is required below 2 GHz, and good sensitivity at the selected band at 4.8 GHz. A sophisticated filtering and triple down -mixing signal processing chain has been designed and implemented in order to achieve the specified 100 dB instantaneous dynamic range without range switching. Detailed design aspects for the complete systems and test results without beam are presented and discussed.

  13. 41 CFR 102-37.60 - How much time does a transferee have to pick up or remove surplus property from holding agency...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false How much time does a transferee have to pick up or remove surplus property from holding agency premises? 102-37.60 Section 102-37... Provisions Donation Overview § 102-37.60 How much time does a transferee have to pick up or remove...

  14. The fundamental power coupler and pick-up of the 56 MHz SRF cavity for RHIC

    SciTech Connect

    Wu, Q.; Bellavia, S.; Ben-Zvi, I.; Pai, C.

    2011-03-28

    A fundamental power coupler (FPC) is designed to provide fast tuning the 56MHz SRF cavity in RHIC. The FPC will be inserted from one of the chemical cleaning ports at the rear end of the cavity with magnetic coupling to the RF field. The size and the location of the FPC are decided based on the required operational external Q of the cavity. The cavity is beam driven, and the FPC is designed with variable coupling that would cover a range of power levels. It is thermally isolated from the base temperature of the cavity, which is 4.2K. A 1kW power amplifier will be used to close an amplitude control feedback loop. In this paper, we discuss the coupling factor of the FPC with the chosen design.

  15. Developmental competence of different quality bovine oocytes retrieved through ovum pick-up following in vitro maturation and fertilization.

    PubMed

    Saini, N; Singh, M K; Shah, S M; Singh, K P; Kaushik, R; Manik, R S; Singla, S K; Palta, P; Chauhan, M S

    2015-12-01

    In the present study, oocytes retrieved from cross bred Karan Fries cows by ovum pick-up technique were graded into Group 1 and Group 2, based on the morphological appearance of the individual cumulus-oocyte complexes (COCs). To analyze whether the developmental potential of the COCs bears a relation to morphological appearance, relative expression of a panel of genes associated with; (a) cumulus-oocyte interaction (Cx43, Cx37, GDF9 and BMP15), (b) fertilization (ZP2 and ZP3), (c) embryonic development (HSF1, ZAR1 and bFGF) and (d) apoptosis and survival (BAX, BID and BCL-XL, MCL-1, respectively) was studied at two stages: germinal vesicle (GV) stage and after in vitro maturation. The competence was further corroborated by evaluating the embryonic progression of the presumed zygotes obtained from fertilization of the graded COCs. The gene expression profile and development rate in pooled A and B grade (Group 1) COCs and pooled C and D grade (Group 2) COCs were determined and compared according to the original grades. The results of the study demonstrated that the morphologically characterized Group 2 COCs showed significantly (P<0.05) lower expression for most of the genes related to cumulus-oocyte interplay, fertilization and embryonic development, both at GV stage as well as after maturation. Group 1 COCs also showed greater expression of anti-apoptotic genes (BCL-XL and MCL1) both at GV stage and after maturation, while pro-apoptotic genes (BAX and BID) showed significantly (P<0.05) elevated expression in poor quality COCs at both the stages. The cleavage rate in Group 1 COCs was significantly higher than that of Group 2 (74.46±7.06 v. 31.57±5.32%). The development of the presumed zygotes in Group 2 oocytes proceeded up to 8- to 16-cell stages only, while in Group 1 it progressed up to morulae (35.38±7.11%) and blastocyst stages (9.70±3.15%), indicating their better developmental potential. PMID:26165355

  16. Cometary kilometric radio waves and plasma waves correlated with ion pick-up effect at Comet Halley

    NASA Technical Reports Server (NTRS)

    Oya, H.; Morioka, A.; Miyake, W.; Smith, E. J.; Tsurutani, B. T.

    1985-01-01

    Bow-shock movements at Comet Halley are inferred from the discrete spectra of the cometary kilometric radiation (30-195 kHz); the observed emissions can be interpreted as being generated and propagating from the moving shock. The shock motion is possibly associated with the time variation of the solar wind and cometary outgassing. It is concluded that these plasma wave phenomena are manifestations of ion pick-up processes, which occur even in a remote region 7 million to 10 million km from the cometary nucleus.

  17. Cometary kilometric radio waves and plasma waves correlated with ion pick-up effect at Comet Halley

    NASA Astrophysics Data System (ADS)

    Oya, H.; Morioka, A.; Miyake, W.; Smith, E. J.; Tsurutani, B. T.

    Bow-shock movements at Comet Halley are inferred from the discrete spectra of the cometary kilometric radiation (30-195 kHz); the observed emissions can be interpreted as being generated and propagating from the moving shock. The shock motion is possibly associated with the time variation of the solar wind and cometary outgassing. It is concluded that these plasma wave phenomena are manifestations of ion pick-up processes, which occur even in a remote region 7 million to 10 million km from the cometary nucleus.

  18. Design and evaluation of pick-up truck mounted boom for elevation of a multiband radiometer system

    NASA Technical Reports Server (NTRS)

    Bauer, M. E. (Principal Investigator); Tsuchida, R.

    1981-01-01

    Three concepts were considered for the boom design: a one-piece boom with a trolley, a folding boom, and a telescoping boom. The telescoping boom was selected over the other two concepts because of its easy manual operation. The boom is designed to mount on the bed of a pick-up truck and elevate the radiometer system 8 meters above the ground and 4 meters away from the truck. The selection of the boom components is discussed with justification of the final choice. Results of performance tests and one season's operation of the completed boom are reported.

  19. 41 CFR 102-37.60 - How much time does a transferee have to pick up or remove surplus property from holding agency...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) FEDERAL MANAGEMENT REGULATION PERSONAL PROPERTY 37-DONATION OF SURPLUS PERSONAL PROPERTY General Provisions Donation Overview § 102-37.60 How much time does a transferee have to pick up or remove...

  20. 41 CFR 102-37.60 - How much time does a transferee have to pick up or remove surplus property from holding agency...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) FEDERAL MANAGEMENT REGULATION PERSONAL PROPERTY 37-DONATION OF SURPLUS PERSONAL PROPERTY General Provisions Donation Overview § 102-37.60 How much time does a transferee have to pick up or remove...

  1. 41 CFR 102-37.60 - How much time does a transferee have to pick up or remove surplus property from holding agency...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) FEDERAL MANAGEMENT REGULATION PERSONAL PROPERTY 37-DONATION OF SURPLUS PERSONAL PROPERTY General Provisions Donation Overview § 102-37.60 How much time does a transferee have to pick up or remove...

  2. 41 CFR 102-37.60 - How much time does a transferee have to pick up or remove surplus property from holding agency...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) FEDERAL MANAGEMENT REGULATION PERSONAL PROPERTY 37-DONATION OF SURPLUS PERSONAL PROPERTY General Provisions Donation Overview § 102-37.60 How much time does a transferee have to pick up or remove...

  3. Pick-up, transport and release of a molecular cargo using a small-molecule robotic arm

    NASA Astrophysics Data System (ADS)

    Kassem, Salma; Lee, Alan T. L.; Leigh, David A.; Markevicius, Augustinas; Solà, Jordi

    2016-02-01

    Modern-day factory assembly lines often feature robots that pick up, reposition and connect components in a programmed manner. The idea of manipulating molecular fragments in a similar way has to date only been explored using biological building blocks (specifically DNA). Here, we report on a wholly artificial small-molecule robotic arm capable of selectively transporting a molecular cargo in either direction between two spatially distinct, chemically similar, sites on a molecular platform. The arm picks up/releases a 3-mercaptopropanehydrazide cargo by formation/breakage of a disulfide bond, while dynamic hydrazone chemistry controls the cargo binding to the platform. Transport is controlled by selectively inducing conformational and configurational changes within an embedded hydrazone rotary switch that steers the robotic arm. In a three-stage operation, 79-85% of 3-mercaptopropanehydrazide molecules are transported in either (chosen) direction between the two platform sites, without the cargo at any time fully dissociating from the machine nor exchanging with other molecules in the bulk.

  4. Electronic Transport of Encapsulated WSe2 Fabricated by Pick-up of Pre-patterned hBN

    NASA Astrophysics Data System (ADS)

    Yang, Yafang; Watanabe, Kenji; Taniguchi, Takashi; Jarillo-Herrero, Pablo; MIT Team

    We report high quality WSe2 devices encapsulated between two hexagonal boron nitride (hBN) flakes using a pick-up method with etched hBN flakes. Previous work on graphene has shown that sample disorder can be greatly reduced via isolation from charge impurities in the substrate by means of encapsulation. However, the effect of encapsulation still remains unknown for dichalcogenides devices. Besides, the quality of contact to TMDs is also a critical factor limiting the transport performance of such devices. To measure the transport properties of dichalcogenide devices as a function of temperature, low resistance electrical contacts must be made to the material. To achieve this, we encapsulate few-layer WSe2 in hexagonal boron nitride that has been patterned to allow ionic liquid doping of the contact region. This technique simultaneously protects the WSe2 surface above and below, resulting in the highest mobility few-layer WSe2 devices reported to date.

  5. Embodied intersubjective engagement in mother–infant tactile communication: a cross-cultural study of Japanese and Scottish mother–infant behaviors during infant pick-up

    PubMed Central

    Negayama, Koichi; Delafield-Butt, Jonathan T.; Momose, Keiko; Ishijima, Konomi; Kawahara, Noriko; Lux, Erin J.; Murphy, Andrew; Kaliarntas, Konstantinos

    2015-01-01

    This study examines the early development of cultural differences in a simple, embodied, and intersubjective engagement between mothers putting down, picking up, and carrying their infants between Japan and Scotland. Eleven Japanese and ten Scottish mothers with their 6- and then 9-month-old infants participated. Video and motion analyses were employed to measure motor patterns of the mothers’ approach to their infants, as well as their infants’ collaborative responses during put-down, pick-up, and carry phases. Japanese and Scottish mothers approached their infants with different styles and their infants responded differently to the short duration of separation during the trial. A greeting-like behavior of the arms and hands was prevalent in the Scottish mothers’ approach, but not in the Japanese mothers’ approach. Japanese mothers typically kneeled before making the final reach to pick-up their children, giving a closer, apparently gentler final approach of the torso than Scottish mothers, who bent at the waist with larger movements of the torso. Measures of the gap closure between the mothers’ hands to their infants’ heads revealed variably longer duration and distance gap closures with greater velocity by the Scottish mothers than by the Japanese mothers. Further, the sequence of Japanese mothers’ body actions on approach, contact, pick-up, and hold was more coordinated at 6 months than at 9 months. Scottish mothers were generally more variable on approach. Measures of infant participation and expressivity indicate more active participation in the negotiation during the separation and pick-up phases by Scottish infants. Thus, this paper demonstrates a culturally different onset of development of joint attention in pick-up. These differences reflect cultures of everyday interaction. PMID:25774139

  6. Cytoskeletal and mitochondrial properties of bovine oocytes obtained by Ovum Pick-Up: the effects of follicle stimulation and in vitro maturation.

    PubMed

    Somfai, Tamás; Matoba, Satoko; Inaba, Yasushi; Nakai, Michiko; Imai, Kei; Nagai, Takashi; Geshi, Masaya

    2015-12-01

    Follicle stimulation by follicular stimulating hormone (FSH) is known to improve developmental competence of bovine oocytes obtained by Ovum Pick-Up (OPU); however, the exact factors in oocytes affected by this treatment have remained unclear. We compared in vitro matured (IVM) oocytes obtained at the immature stage from cows by OPU either without or with stimulation with FSH (non-stimulated and stimulated OPU, respectively) to those obtained by superstimulation and in vivo maturation in terms of cytoskeleton morphology, mitochondrial distribution, intracellular adenosine triphosphate (ATP) content and H2 O2 levels at the metaphase-II stage and intracellular Ca(2+) levels after in vitro fertilization (IVF). Confocal microscopy after immunostaining revealed reduced size of the meiotic spindle, associated with increased tendencies of microfilament degradation and insufficient mitochondrial re-distribution in non-stimulated OPU-derived IVM oocytes compared with those collected by stimulated OPU, which in turn resembled in vivo matured oocytes. However, there was no difference in mitochondrial functions between oocytes obtained by stimulated or non-stimulated OPU in terms of ATP content, cytoplasmic H2 O2 levels, base Ca(2+) levels and the frequencies and amplitudes of Ca(2+) oscillations after IVF. Larger size of metaphase spindles in oocytes obtained by stimulated OPU may reflect and potentially contribute to their high developmental competence. PMID:26154026

  7. STEM Picks Up Speed

    ERIC Educational Resources Information Center

    Demski, Jennifer

    2009-01-01

    Algebra, geometry, earth science, physics--these require patience and perseverance to master. That kind of academic stamina is hard to advertise to kids nurtured on the instant engagement and gratification of modern digital technology. And there's little hope they'll be sustained by an intrinsic interest in math and science; they have to be shown…

  8. Picking Up the Pieces

    ERIC Educational Resources Information Center

    Robelen, Erik W.

    2005-01-01

    A school devastated by Hurricane Katrina, which struck southeastern Louisiana on August 29, reopens--but for teachers, the real work is just beginning. First, there was the storm. Roofing was ripped off some of the beige, block like buildings that make up Bonnabel High's nondescript campus nestled in a suburban neighborhood near the New Orleans…

  9. Electronic Transport of Encapsulated WSe2 Fabricated by Pick-up of Pre-patterned hBN

    NASA Astrophysics Data System (ADS)

    Yang, Yafang; Churchill, Hugh; Watanabe, Kenji; Taniguchi, Takashi; Jarillo-Herrero, Pablo

    2015-03-01

    We report high quality WSe2 devices encapsulated between two hexagonal boron nitride (hBN) flakes using a pick-up method with etched hBN flakes. Previous work on graphene has shown that sample disorder can be greatly reduced via isolation from charge impurities in the substrate by means of encapsulation. However, the effect of encapsulation still remains unknown for dichalcogenides devices. Besides, the quality of contact to TMDs is also a critical factor limiting the transport performance of such devices. To measure the transport properties of dichalcogenide devices as a function of temperature, low resistance electrical contacts must be made to the material. To achieve this, we encapsulate few-layer WSe2 in hexagonal boron nitride that has been patterned to allow ionic liquid doping of the contact region. This technique simultaneously protects the WSe2 surface above and below, resulting in the highest mobility few-layer WSe2 devices reported to date. We acknowledge support from ONR Young Investigator Award N00014-13-1-0610.

  10. Phenotypic correlations between ovum pick-up in vitro production traits and pregnancy rates in Zebu cows.

    PubMed

    Vega, W H O; Quirino, C R; Serapião, R V; Oliveira, C S; Pacheco, A

    2015-01-01

    The growth of the Gyr breed in Brazil in terms of genetic gain for milk, along with conditions for market, has led to the use of ovum pick-up in vitro production (OPU-IVP) as a leader in biotechnology for the multiplication of genetic material. The aim of this study was to investigate phenotypic correlations between OPU-IVP-linked characteristics and pregnancy rates registered in an embryo transfer program using Gyr cows as oocyte donors. Data collected from 211 OPU sessions and 298 embryo transfers during the years 2012 and 2013 were analyzed and statistical analysis was performed. Estimates of simple Pearson correlations were calculated for NVcoc and PVcoc (number and proportion of viable cumulus-oocyte complexes, respectively); NcleavD4 and PcleavD4 (number and proportion of cleaved embryos on day 4 of culture, respectively); NTembD7 and PTembD7 (number and proportion of transferable embryos on day 7 of culture, respectively); NPrD30 and PPrD30 (number and proportion of pregnancies 30 days after transfer, respectively); and NPrD60 and PPrD60 (number and proportion of pregnancies 60 days after transfer, respectively). Moderate to moderately high correlations were found for all numerical characteristics, suggesting these as the most suitable parameters for selection of oocyte donors in Gyr programs. NVcoc is proposed as a selection trait due to positive correlations with percentage traits and pregnancy rates 30 and 60 days after transfer. PMID:26214412

  11. Pico Lantern: Surface reconstruction and augmented reality in laparoscopic surgery using a pick-up laser projector.

    PubMed

    Edgcumbe, Philip; Pratt, Philip; Yang, Guang-Zhong; Nguan, Christopher; Rohling, Robert

    2015-10-01

    The Pico Lantern is a miniature projector developed for structured light surface reconstruction, augmented reality and guidance in laparoscopic surgery. During surgery it will be dropped into the patient and picked up by a laparoscopic tool. While inside the patient it projects a known coded pattern and images onto the surface of the tissue. The Pico Lantern is visually tracked in the laparoscope's field of view for the purpose of stereo triangulation between it and the laparoscope. In this paper, the first application is surface reconstruction. Using a stereo laparoscope and an untracked Pico Lantern, the absolute error for surface reconstruction for a plane, cylinder and ex vivo kidney, is 2.0 mm, 3.0 mm and 5.6 mm, respectively. Using a mono laparoscope and a tracked Pico Lantern for the same plane, cylinder and kidney the absolute error is 1.4 mm, 1.5 mm and 1.5 mm, respectively. These results confirm the benefit of the wider baseline produced by tracking the Pico Lantern. Virtual viewpoint images are generated from the kidney surface data and an in vivo proof-of-concept porcine trial is reported. Surface reconstruction of the neck of a volunteer shows that the pulsatile motion of the tissue overlying a major blood vessel can be detected and displayed in vivo. Future work will integrate the Pico Lantern into standard and robot-assisted laparoscopic surgery. PMID:26024818

  12. Catalytic Propulsion and Magnetic Steering of Soft, Patchy Microcapsules: Ability to Pick-Up and Drop-Off Microscale Cargo.

    PubMed

    Lu, Annie Xi; Liu, Yijing; Oh, Hyuntaek; Gargava, Ankit; Kendall, Eric; Nie, Zhihong; DeVoe, Don L; Raghavan, Srinivasa R

    2016-06-22

    We describe the creation of polymeric microcapsules that can exhibit autonomous motion along defined trajectories. The capsules are made by cross-linking aqueous microdroplets of the biopolymer chitosan using glutaraldehyde. A coflow microfluidic tubing device is used to generate chitosan droplets containing nanoparticles (NPs) with an iron (Fe) core and a platinum (Pt) shell. The droplets are then incubated in a Petri dish with the cross-linking solution, and an external magnet is placed below the Petri dish to pull the NPs together as a collective "patch" on one end of each droplet. This results in cross-linked capsules (∼150 μm in diameter) with an anisotropic (patchy) structure. When these capsules are placed in a solution of H2O2, the Pt shell of the NPs catalyzes the decomposition of H2O2 into O2 gas, which is ejected from the patchy end in the form of bubbles. As a result, the capsules (which are termed micromotors) move in a direction opposite to the bubbles. Furthermore, the micromotors can be steered along specific paths by an external magnet (the magnetic response arises due to the Fe in the core of the NPs). A given micromotor can thus be directed to meet with and adhere to an inert capsule, i.e., a model cargo. Adhesion occurs due to the soft nature of the two structures. Once the cargo is picked up, the micromotor-cargo pair can be moved along a specific path to a destination, whereupon the cargo can be released from the micromotor. We believe these soft micromotors offer significant benefits over their existing hard counterparts because of their biocompatibility, biodegradability, and ability to encapsulate a variety of payloads. PMID:27295420

  13. Ovarian follicular dynamics, follicle deviation, and oocyte yield in Gyr breed (Bos indicus) cows undergoing repeated ovum pick-up.

    PubMed

    Viana, J H M; Palhao, M P; Siqueira, L G B; Fonseca, J F; Camargo, L S A

    2010-04-15

    The objective of this study was to evaluate ovarian follicular dynamics during intervals between successive ovum pick-up (OPU) and determine its effects on the number and quality of recovered cumulus-oocyte complexes (COCs) in Zebu cows (Bos indicus). Pluriparous nonlactating Gyr cows (Bos indicus; n=10) underwent four consecutive OPU sessions at 96-h intervals. The dynamics of ovarian follicular growth between OPU sessions was monitored by twice-daily ultrasonographic examinations. A single dominant follicle (DF) or two codominant (CDF) follicles (>9mm) were present in 63.3% (19 of 30) of intervals studied, with follicle deviation beginning when the future dominant follicle (F1) achieved a diameter of 6.2+/-0.3mm. The phenomenon of codominance was observed in four (13.3%) of the inter-OPU intervals. The remaining intervals (36.6%, 11 of 30) were characterized by a greater follicular population, lower rate of follicular growth, and a smaller diameter F1 (P<0.0001). There was a tendency (P=0.08) toward an increase in the number of recovered COCs when dominant follicles were not present (NDF). The quality of COCs was not affected by the presence of a single dominant follicle, but codominant follicles resulted in recovery of a lower proportion of viable embryos (40.0%, 62.1%, and 63.6%; P<0.05) and higher proportions of degenerate COCs (56.0%, 30.3%, and 28.6%; P<0.05) for CDF, NDF, and DF respectively. We concluded that, in Zebu cows, (a) repeated follicle aspirations altered ovarian follicular dynamics, perhaps by increasing follicular growth rate; (b) follicular dominance could be established in cows undergoing twice-a-week OPU; and (c) the presence of a dominant follicle during short inter-OPU intervals may not affect COC quality, except when a codominant follicle was present. PMID:20071017

  14. Effects of eCG and FSH on ovarian response, recovery rate and number and quality of oocytes obtained by ovum pick-up in Holstein cows.

    PubMed

    Sendag, Sait; Cetin, Yunus; Alan, Muhammet; Hadeler, Klaus-Gerd; Niemann, Heiner

    2008-06-01

    The goal of the present study was to compare the ovarian response, oocyte yields per animal, and the morphological quality of oocytes collected by ultrasound guided follicular aspiration from Holstein cows treated either with FSH or eCG. Twenty four normal cyclic, German Holstein cows were randomly divided into two groups. Fourteen cows received 3000 IU eCG on day-4 prior to ovum pick-up (OPU) (day 0), 2 days later (day-2), 625 microg cloprostenol was administered. On day-1 GnRH was administered i.m. and 24h later OPU (day 0) was performed. In ten cows a total dose of 500 IU follicle stimulating hormone (Pluset) was administered intramuscularly in a constant dosage for 4 days with intervals of 12h, starting on day-5. Luteolysis was induced by application of 625 microg cloprostenol on day-2. On day-1 (24h after the last FSH treatment) GnRH was administered i.m. and 24h later OPU (day 0) was performed. Ovarian follicles were visualized on the ultrasound monitor, counted and recorded. All visible antral follicles were punctured. Recovered oocytes were graded morphologically based on the cumulus investment. Average follicle number in ovaries was higher in FSH group than eCG group (p<0.05). Oocyte yields per animal did not differ between FSH and eCG groups. The proportion of grade A oocytes was higher in the FSH group in the than eCG group (p<0.05). Likewise, rate of grade C oocytes in FSH group were lower than eCG group (p<0.05). In conclusion, these results suggest that ovarian response, follicle number in ovaries and oocyte quality are affected by the type of gonadotropin and FSH is better alternative than eCG for OPU treatment. PMID:18294785

  15. Ovum pick up in swine: the influence of aspiration vacuum pressure on oocyte recovery from preovulatory follicles.

    PubMed

    Brüssow, K P; Torner, H; Rátky, J; Hunter, M G; Nürnberg, G

    1997-01-01

    Endoscopical ovum pick up (OPU) in swine is a minimal invasive and reliable technique to aspirate oocytes from preovulatory follicles for studying intrafollicular development and oocyte maturation as well as for IVM/IVF-programs. The aim of the present study was to determine the effect of different aspiration vacuum pressures on oocyte recovery and on the morphology of cumulus oocyte complexes (COCs). Oestrus of crossbred Landrace gilts (n = 33) was synchronized by feeding altrenogest and follicular growth was stimulated with 1,000 IU PMSG 24 h after the last altrenogest application. On day 4 after PMSG application preovulatory healthy follicles of > 5 mm diameter were aspirated laparoscopically. Aspiration was carried out using a two-way cannula and an electronic aspiration pump. Five different vacuum pressures were used: 10, 17, 32, 47 and 66 ml water/min, corresponding to 30, 60, 125, 250 and 375 mm Hg, respectively. Fluids from different follicles were pooled per ovary and the morphology of cumulus oocyte complexes (COCs) was determined microscopically immediately after aspiration. COCs were classified into oocytes with intact cumulus (i.e. compact or slightly expanded COC), oocytes with corona radiata and denuded oocytes. A total of 695 follicles were aspirated and 501 COCs recovered. Increasing the aspiration pressure stepwise from 10 ml water/min up to 66 ml water/min resulted in a decrease in oocyte recovery rate. A significant higher (P < 0.05) rate of oocyte recovery (77.4% v.s. 59.8%) was achieved using a vacuum pressure of 17 ml water/min compared to 66 ml water/min, respectively. There was a tendency to reduce the portion of COCs with intact cumulus from 82 to 88% to 77% if the vacuum pressure increased to more than 47 ml water/min. A higher aspiration pressure provoked an increase (P < 0.05) in the number of denuded oocytes: 0 to 3% at 10 to 32 ml water/min, respectively, compared to 10% at 47 ml water/min to 17% at 66 ml water/min. These results

  16. Laparoscopic ovum pick-up and in vitro production of sika deer embryos: effect of season and culture conditions.

    PubMed

    Locatelli, Y; Vallet, J C; Huyghe, F P; Cognié, Y; Legendre, X; Mermillod, P

    2006-09-15

    Amongst the 200 deer subspecies worldwide, more than 40 are considered as endangered. In vitro embryo production may represent an efficient way to produce and disseminate offspring from sparse remaining individuals in these species. With a view to establishing a method of in vitro embryo production, we assessed the ovarian response after hormonal stimulation (oFSH), oocyte yield following laporoscopic ovum pick-up (LOPU) and oocyte developmental competence according to seasonal reproductive status in sika deer (Cervus nippon nippon). Twelve adult sika deer hinds were allocated between two groups and submitted weekly to oFSH follicular growth stimulation followed by LOPU. Hinds in Group A (n=6) were treated first during the breeding season (5 weeks), and then during the non-breeding season (3 weeks). Hinds in Group B (n=6) were submitted to similar procedures but in the reverse order (treated first during the non-breeding season). Cumulus-oocytes complexes (COC) recovered from Group B were allowed to mature in vitro for 24 h in TCM-199 medium supplemented with oFSH, goat follicular fluid and 100 microM cysteamine. In vitro fertilization was performed with frozen/thawed semen in SOFaa medium supplemented with 20% estrous sheep serum and presumptive zygotes were cultured in the presence or absence of ovine oviductal epithelial cell monolayer (oOEC) in SOFaa-BSA medium. Mean number of follicles aspirated per hind per session decreased significantly between breeding and non-breeding season in Group A (9.8+/-0.7 versus 3.2+/-0.7, mean+/-S.E.M., respectively, P<0.001) but did not change between the non-breeding and the subsequent breeding season in Group B (5.3+/-0.7 and 5.7+/-0.7, respectively, P>0.05). Irrespective of the season, good quality COC with complete and compact cumulus investments were recovered allowing a high cleavage rate after in vitro maturation and fertilization. Whereas development to the blastocyst stage did not occur in SOF medium alone, high

  17. Pick-up ions at Comet P/Halley's bow shock - Observations with the IIS spectrometer on Giotto. [Implanted In Spectrometer

    NASA Technical Reports Server (NTRS)

    Wilken, B.; Johnstone, A.; Coates, A.; Amata, E.; Borg, H.

    1987-01-01

    Gaseous material expanding from the nucleus of Comet Halley into space forms the neutral coma around the comet. Ionization in the solar UV radiation removes particles from the coma and injects them into the solar wind plasma. These freshly created ions are accelerated by the interplanetary electric field on cycloidal trajectories with gyrocenters moving with the speed of the magnetic field lines. In the solar wind frame of reference these particles move along the magnetic field lines with a fixed pitch angle. Pitch-angle scattering and energy diffusion reduce quickly the initial energy anisotropy which is associated with the narrow pick-up structures. First observations of heavy cometary pick-up ions (water group ions) at the bow shock are presented. The evolution of the distribution function in the vicinity of the shock and radial density profiles are discussed.

  18. Do umbilical outpouchings affect the behaviour or clinical condition of pigs during 6 h housing in a pre-transport pick-up facility?

    PubMed

    Schild, Sarah-Lina Aa; Rousing, Tine; Jensen, Henrik E; Barington, Kristiane; Herskin, Mette S

    2015-08-01

    This study focused on behavioural and clinical effects of umbilical outpouchings (UOs) in pigs. Matched pairs of pigs with UOs (diameter 12 cm; range 4-20; diagnosed p.m. as hernia or non-hernia) and controls (N=28) were compared during a 6-h stay in a pick-up facility. Overall, skin lesion scores were increased after the 6-h stay. Behaviour of the UO-pigs differed from the controls (a shorter latency to lie down (P<0.05) and decreased aggression (P<0.05)). Pigs with umbilical hernia showed e.g. increased sitting (P<0.05) and decreased lying (P<0.05) compared to pigs with non-hernia UOs. No effects of the size of the OUs were found. These results are among the first to establish knowledge about UO-pigs and suggest that a stay in a pick-up facility can be challenging for pig welfare. The behavioural findings suggest that UO-pigs, and especially pigs with hernia, may be less fit for mixing and housing in barren environments. PMID:26267102

  19. In-situ observations of cometary pick-up ions greater than 0.2 AU upstream of Comet Halley - ICE observations

    NASA Astrophysics Data System (ADS)

    Wenzel, K.-P.; Sanderson, T. R.; Richardson, I. G.; Cowley, S. W. H.; Hynds, R. J.; Bame, S. J.; Zwickl, R. D.; Smith, E. J.; Tsurutani, B. T.

    1986-08-01

    Burst-like enhancements of energetic ions were observed by the EPAS instrument on the International Cometary Explorer (ICE) during its closest approach to (28 x 10 to the 6th km upstream of) Comet P/Halley, in late March 1986. The ion intensity was modulated by the varying solar wind speed (the latter reaching maxima of around 600 km/s), as was found to be the case for heavy cometary ions accelerated by pick-up in the solar wind flow, during the ICE encounter with Comet P/Giacobini-Zinner (G-Z). Therefore it is concluded that the observed pick-up ions (most probably greater than or equal to 65 keV oxygen ions) are produced by heavy neutrals from Comet Halley. The observations of energetic ions at such large distances suggest the presence, in the neutral atmosphere surrounding the nucleus, of a component with an ionization scale length of 5-10 million km, resulting from a relatively high expansion speed of a few km/s and/or an ionization time scale of a few times 10 to the 6ths.

  20. Beam current sensor

    DOEpatents

    Kuchnir, Moyses; Mills, Frederick E.

    1987-01-01

    A current sensor for measuring the DC component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivites in the nano-ampere range.

  1. Beam current sensor

    DOEpatents

    Kuchnir, M.; Mills, F.E.

    1984-09-28

    A current sensor for measuring the dc component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivities in the nano-ampere range.

  2. TOPOLOGY FOR A DSP BASED BEAM CONTROL SYSTEM IN THE AGS BOOSTER.

    SciTech Connect

    DELONG,J.BRENNAN,J.M.HAYES,T.LE,T.N.SMITH,K.

    2003-05-12

    The AGS Booster supports beams of ions and protons with a wide range of energies on a pulse-by-pulse modulation basis. This requires an agile beam control system highly integrated with its controls. To implement this system digital techniques in the form of Digital Signal Processors, Direct Digital Synthesizers, digital receivers and high speed Analog to Digital Converters are used. Signals from the beam and cavity pick-ups, as well as measurements of magnetic field strength in the ring dipoles are processed in real time. To facilitate this a multi-processor topology with high bandwidth data links is being designed.

  3. Case of ovarian hyperstimulation and oocyte pick-up during very early period of unnoticed pregnancy followed by ongoing normal pregnancy.

    PubMed

    Takenaka, Hiroshi; Nakao, Kazuki; Horikawa, Michiharu; Negishi, Hiroaki

    2016-04-01

    We report a case of unnoticed pregnancy that was maintained during low estrogen and progesterone circumstances, that showed menses-like bleeding, and was then discovered after ovarian hyperstimulation during the next period. The patient was 39 years old and primigravid. She underwent intrauterine insemination, followed by luteal support with human chorionic gonadotrophin and progestin; however, she experienced menstruation-like bleeding 15 days later. As low estradiol and progesterone levels were confirmed on the 2nd day of bleeding, ovarian hyperstimulation of short protocol for in vitro fertilization was commenced. Although 13 mature follicles were observed, only six oocytes were retrieved and one developed into a blastocyst. Four days after oocyte pick-up, a gestational sac was seen in utero. The fetus is currently growing uneventfully. This case suggests that pregnancy can be maintained during ovarian hyperstimulation, even if menstruation-like bleeding is shown in low-progesterone circumstances. PMID:26869522

  4. Quantification of rolling circle amplified DNA using magnetic nanobeads and a Blu-ray optical pick-up unit.

    PubMed

    Donolato, Marco; Antunes, Paula; de la Torre, Teresa Zardán Gómez; Hwu, En-Te; Chen, Ching-Hsiu; Burger, Robert; Rizzi, Giovanni; Bosco, Filippo Giacomo; Strømme, Maria; Boisen, Anja; Hansen, Mikkel Fougt

    2015-05-15

    We present the first implementation of a Blu-ray optical pickup unit (OPU) for the high-performance low-cost readout of a homogeneous assay in a multichamber microfluidic disc with a chamber thickness of 600 μm. The assay relies on optical measurements of the dynamics of magnetic nanobeads in an oscillating magnetic field applied along the light propagation direction. The laser light provided by the OPU is transmitted through the sample chamber and reflected back onto the photo detector array of the OPU via a mirror. Spectra of the 2nd harmonic photo detector signal vs. the frequency of the applied magnetic field show a characteristic peak due to freely rotating magnetic nanobeads. Beads bound to ~1 μm coils of DNA formed off-chip by padlock probe recognition and rolling circle amplification show a different dynamics and the intensity of the characteristic peak decreases. We have determined the optimum magnetic bead concentration to 0.1mg/mL and have measured the response vs. concentration of DNA coils formed from Escherichia Coli. We have found a limit of detection of 10 pM and a dynamic range of about two orders of magnitude, which is comparable to the performance obtained using costly and bulky laboratory equipment. The presented device leverages on the advanced but low-cost technology of Blu-ray OPUs to provide a low-cost and high-performance magnetic bead-based readout of homogeneous bioassays. The device is highly flexible and we have demonstrated its use on microfluidic chambers in a disc with a thickness compatible with current optical media mass-production facilities. PMID:25453736

  5. Pick up a book or "google it?" a survey of radiologist and trainee-preferred references and resources.

    PubMed

    Niederhauser, Blake D; Liaw, Kevin; McDonald, Robert J; Thomas, Kristen B; Hudson, Kathleen T; Kallmes, David F

    2014-02-01

    The purpose of this study was to investigate radiologist and trainee-preferred sources for solving imaging questions. The institutional review board determined this study to be exempt from informed consent requirements. Web-based surveys were distributed to radiology staff and trainees at 16 academic institutions. Surveys queried ownership and use of tablet computers and habits of utilization of various electronic and hardcopy resources for general reference. For investigating specific cases, respondents identified a single primary resource. Comparisons were performed using Fisher's exact test. For staff, use of Google and online journals was nearly universal for general imaging questions (93 [103/111] and 94 % [104/111], respectively). For trainees, Google and resident-generated study materials were commonly utilized for such questions (82 [111/135] and 74 % [100/135], respectively). For specific imaging questions, online journals and PubMed were rarely chosen as a primary resource; the most common primary resources were STATdx for trainees and Google for staff (44 [55/126] and 52 % [51/99], respectively). Use of hard copy journals was nearly absent among trainees. Sixty percent of trainees (78/130) own a tablet computer versus 41 % of staff (46/111; p = 0.005), and 71 % (55/78) of those trainees reported at least weekly use of radiology-specific tablet applications, compared to 48 % (22/46) of staff (p < 0.001). Staff radiologists rely heavily on Google for both general and specific imaging queries, while residents utilize customized, radiology-focused products and apps. Interestingly, residents note continued use of hard copy books but have replaced hard copy journals with online resources. PMID:24052213

  6. Cherenkov Light-based Beam Profiling for Ultrarelativistic Electron Beams

    SciTech Connect

    Adli, E.; Gessner, S. J.; Corde, S.; Hogan, M. J.; Bjerke, H. H.

    2015-02-09

    We describe a beam profile monitor design based on Cherenkov light emitted from a charged particle beam in an air gap. The main components of the profile monitor are silicon wafers used to reflect Cherenkov light onto a camera lens system. The design allows for measuring large beam sizes, with large photon yield per beam charge and excellent signal linearity with beam charge. Furthermore, the profile monitor signal is independent of the particle energy for ultrarelativistic particles. Different design and parameter considerations are discussed. A Cherenkov light-based profile monitor has been installed at the FACET User Facility at SLAC. Finally, we report on the measured performance of this profile monitor.

  7. Clinic Attendance for Antiretroviral Pills Pick-Up among HIV-Positive People in Nepal: Roles of Perceived Family Support and Associated Factors

    PubMed Central

    Kikuchi, Kimiyo; Ghimire, Mamata; Shibanuma, Akira; Pant, Madhab Raj; Poudel, Krishna C.; Jimba, Masamine

    2016-01-01

    Introduction HIV-positive people’s clinic attendance for medication pick-up is critical for successful HIV treatment. However, limited evidence exists on it especially in low-income settings such as Nepal. Moreover, the role of family support in clinic attendance remains under-explored. Therefore, this study was conducted to examine the association between perceived family support and regular clinic attendance and to assess factors associated with regular clinic attendance for antiretroviral pills pick-up among HIV-positive individuals in Nepal. Methods A cross-sectional study was conducted among 423 HIV-positive people in three districts of Nepal. Clinic attendance was assessed retrospectively for the period of 12 months. To assess the factors associated, an interview survey was conducted using a semi-structured questionnaire from July to August, 2015. Multiple logistic regression models were used to assess the factors associated with regular clinic attendance. Results Of 423 HIV-positive people, only 32.6% attended the clinics regularly. They were more likely to attend them regularly when they received high family support (AOR = 3.98, 95% CI = 2.29, 6.92), participated in support programs (AOR = 1.68, 95% CI = 1.00, 2.82), and had knowledge on the benefits of antiretroviral therapy (AOR = 2.62, 95% CI = 1.15, 5.99). In contrast, they were less likely to attend them regularly when they commuted more than 60 minutes to the clinics (AOR = 0.53, 95% CI = 0.30, 0.93), when they self-rated their health status as being very good (AOR = 0.13, 95% CI = 0.04, 0.44), good (AOR = 0.14, 95% CI = 0.04, 0.46), and fair (AOR = 0.21, 95% CI = 0.06, 0.70). Conclusion HIV-positive individuals are more likely to attend the clinics regularly when they receive high family support, know the benefits of antiretroviral therapy, and participate in support programs. To improve clinic attendance, family support should be incorporated with HIV care programs in resource limited settings

  8. Improved embryo development in Japanese black cattle by in vitro fertilization using ovum pick-up plus intracytoplasmic sperm injection with dithiothreitol.

    PubMed

    Oikawa, Toshinori; Itahashi, Tomoko; Numabe, Takashi

    2016-01-01

    The purpose of this study was to determine whether dithiothreitol (DTT) treatment of sperm and ethanol activation improve embryo production by intracytoplasmic sperm injection (ICSI). Further, we compared ICSI with standard in vitro fertilization (IVF) in oocytes obtained from cattle. We demonstrated that DTT reduced the disulfide bond in the bovine sperm head. Using oocytes obtained from a slaughterhouse, ICSI-DTT treatment without ethanol showed the highest rate of blastocyst formation. We applied these results to fertilization using ovum pick-up (OPU). Eleven Japanese black cattle served as donors for OPU plus standard IVF (OPU-IVF). Of them, four donors with low embryo development rates were selected to determine whether embryo development was enhanced by OPU plus ICSI (OPU-ICSI). We assessed effects on embryo development following IVF and ICSI in oocytes obtained using OPU. Blastocyst rates were significantly higher for OPU-ICSI than for OPU-IVF. Our results suggest that OPU-ICSI improves the blastocyst development rate in donors with low embryo production compared with the standard OPU-IVF. PMID:26460690

  9. Anti-Muellerian hormone levels in plasma of Holstein-Friesian heifers as a predictive parameter for ovum pick-up and embryo production outcomes

    PubMed Central

    VERNUNFT, Andreas; SCHWERHOFF, Mona; VIERGUTZ, Torsten; DIEDERICH, Mike; KUWER, Andreas

    2014-01-01

    The aim of this study was to investigate whether plasma anti-Muellerian hormone (AMH) levels of Holstein-Friesian heifers could be used to predict ovum pick-up (OPU) and embryo production outcomes. Plasma samples and data were collected from 64 heifers, which underwent repeated OPU with subsequent in vitro embryo production followed by embryo flushing after superovulation. AMH levels were significantly positively correlated with the number of follicles aspirated per OPU session (r = 0.45), recovered oocytes per OPU (r =0.43) and in vitro produced embryos per OPU (r = 0.28). No significant correlations between AMH and in vivo produced embryos were ascertained. Our results suggest that correlations between AMH and outcomes of an OPU-IVF program are too low to use AMH as a precise predictive parameter for the success of a particular OPU procedure in Holstein-Friesian heifers. However, AMH can help to identify groups of very good or very poor oocyte donors. PMID:25482112

  10. The effects of twisting and type of aspiration needle on the efficiency of transvaginal ultrasound-guided ovum pick-up in cattle.

    PubMed

    Sasamoto, Yoshihiko; Sakaguchi, Minoru; Katagiri, Seiji; Yamada, Yutaka; Takahashi, Yoshiyuki

    2003-10-01

    The effects of twisting and type (single- or double-lumen) of aspiration needle on the efficiency of transvaginal ultrasound-guided ovum pick-up (US-guided OPU) were investigated in cattle. The first study using slaughterhouse ovaries revealed that twisting of the needle during follicle aspiration improved the oocyte recovery rate without deleterious effects on the attachment of cumulus layers. Vacuum pressure affected the oocyte recovery and cumulus attachment, regardless of the needle type. The needle type did not affect the oocyte recovery or cumulus attachment with an optimized vacuum pressure. In the second study, US-guided OPU was performed in live cows using two types of needles with a vacuum pressure of 75 mmHg. The needle type did not affect the oocyte recovery or cumulus attachment of the recovered oocytes. The results revealed that twisting of the needle is effective in follicle aspiration, and suggested that a single-lumen needle is as useful as a double-lumen needle for US-guided OPU in cattle. PMID:14600345

  11. Improved embryo development in Japanese black cattle by in vitro fertilization using ovum pick-up plus intracytoplasmic sperm injection with dithiothreitol

    PubMed Central

    OIKAWA, Toshinori; ITAHASHI, Tomoko; NUMABE, Takashi

    2015-01-01

    The purpose of this study was to determine whether dithiothreitol (DTT) treatment of sperm and ethanol activation improve embryo production by intracytoplasmic sperm injection (ICSI). Further, we compared ICSI with standard in vitro fertilization (IVF) in oocytes obtained from cattle. We demonstrated that DTT reduced the disulfide bond in the bovine sperm head. Using oocytes obtained from a slaughterhouse, ICSI-DTT treatment without ethanol showed the highest rate of blastocyst formation. We applied these results to fertilization using ovum pick-up (OPU). Eleven Japanese black cattle served as donors for OPU plus standard IVF (OPU-IVF). Of them, four donors with low embryo development rates were selected to determine whether embryo development was enhanced by OPU plus ICSI (OPU-ICSI). We assessed effects on embryo development following IVF and ICSI in oocytes obtained using OPU. Blastocyst rates were significantly higher for OPU-ICSI than for OPU-IVF. Our results suggest that OPU-ICSI improves the blastocyst development rate in donors with low embryo production compared with the standard OPU-IVF. PMID:26460690

  12. What is the most relevant standard of success in assisted reproduction?: The cumulated singleton/twin delivery rates per oocyte pick-up: the CUSIDERA and CUTWIDERA.

    PubMed

    Germond, Marc; Urner, Françoise; Chanson, Alain; Primi, Marie-Pierre; Wirthner, Daniel; Senn, Alfred

    2004-11-01

    National and international registries are essential tools for establishing new standards and comparing success rates, but they do not take into account the total pregnancy/delivery rate per oocyte recovery. In Switzerland and Germany, because of legal constraints, a maximum of three two-pronuclear zygotes are allocated for transfer whereas all the supernumerary pronuclear zygotes are immediately cryopreserved, preventing selection of the transferred embryos. We report on a 10 years' experience (1993-2002) of our centre which performs transfers of unselected embryos and cryopreservation at the two-pronuclear zygote stage. As approximately 30% of all deliveries are from cryo cycles, it is essential to take into account the contribution of the cryo transfers, and we propose therefore to evaluate, as a measure of IVF performance, the cumulated delivery rate per oocyte pick-up. This delivery rate is broken down further into the cumulated singleton delivery rate (CUSIDERA) and the cumulated twin delivery rate (CUTWIDERA). The sum (S) of these two rates is a measure of efficacy while the ratio CUTWIDERA/S as a percentage is a measure of safety of IVF treatments. Using these new indexes, the average 10 year efficacy and safety of our IVF programme were 26 and 19%, respectively. Both CUSIDERA and CUTWIDERA can be calculated easily in any clinical situation and yield useful parameters for patient counselling and internal/external benchmarking purposes. PMID:15358719

  13. Ovum pick up, in vitro embryo production, and pregnancy rates from a large-scale commercial program using Nelore cattle (Bos indicus) donors.

    PubMed

    Pontes, J H F; Melo Sterza, F A; Basso, A C; Ferreira, C R; Sanches, B V; Rubin, K C P; Seneda, M M

    2011-06-01

    The objective was to clarify in vitro production of bovine embryos in Brazil. Data from 656 ovum pick-up/in vitro production (OPU/IVP) procedures, performed on 317 Nelore (Bos indicus) donors, without hormone stimulation or control of ovarian follicular waves, were analysed. Donors were subjected to OPU from one to nine times (no specific schedule), with < 15 d between consecutive procedures. There were 20,848 oocytes, of which 15,747 (75.53%) were considered viable, 5,446 embryos were obtained, 5,398 embryos were immediately transferred, resulting in 1,974 pregnancies (36.57%) at Day 30 and 1,788 (33.12%) pregnancies at Day 60. The average number of total and viable oocytes produced per OPU session was (mean ± SEM) 30.84 ± 0.88 and 23.35 ± 0.7 (average of 8.1 ± 0.3 embryos and 3.0 ± 0.1 pregnancies per OPU-IVP procedure). Since oocyte production varied widely among donor, they were designated as very high, high, intermediate, and low, with 58.94 ± 2.04, 32.61 ± 0.50, 22.13 ± 0.50, and 10.26 ± 0.57 oocytes, respectively, produced by 78, 80, 79, and 80 donors. The number of viable oocytes recovered ranged from 0 to 128; since donors with numerous viable oocytes produced many viable embryos and pregnancies, oocyte production was useful for donor selection. However, there was no significant effect of the number of OPU sessions per donor on mean numbers of oocytes produced. In conclusion, we confirmed field reports of high oocyte production by some Nelore donors and demonstrated individual variation in oocyte yield, which was associated with embryo production and pregnancy rates. PMID:21334055

  14. Picking up the pieces”—Meanings of receiving home nursing care when being old and living with advanced cancer in a rural area

    PubMed Central

    Devik, Siri Andreassen; Hellzen, Ove; Enmarker, Ingela

    2015-01-01

    Rural home nursing care is a neglected area in the research of palliative care offered to older cancer patients. Because access to specialized services is hampered by long distances and fragmented infrastructure, palliative care is often provided through standard home nursing services and delivered by general district nurses. This study aimed to illuminate the lived experience and to interpret the meaning of receiving home nursing care when being old and living with advanced cancer in a rural area in Norway. Narrative interviews were conducted with nine older persons, and a phenomenological hermeneutic approach was used to interpret the meaning of the lived experience. The analysis revealed three themes, each with subthemes: being content with what one gets, falling into place, and losing one's place. The phrase picking up the pieces was found useful to sum up the meaning of this lived experience. The three respective themes refer to how the pieces symbolize the remaining parts of life or available services in their environment, and how the older persons may see themselves as pieces or bricks in a puzzle. A strong place attachment (physical insideness, social insideness, and autobiographical insideness) is demonstrated by the informants in this study and suggests that the rural context may provide an advantageous healthcare environment. Its potential to be a source of comfort, security, and identity concurs with cancer patients’ strong desire for being seen as unique persons. The study shows that district nurses play an essential role in the provision of palliative care for older rural patients. However, the therapeutic value of being in one's familiar landscape seems to depend on how homecare nurses manage to locate it and use it in a more or less person-centred manner. Communication skills and attentiveness to psychosocial aspects of patient care stand out as important attributes for nursing in this context. PMID:26362533

  15. "Picking up the pieces" - Meanings of receiving home nursing care when being old and living with advanced cancer in a rural area.

    PubMed

    Devik, Siri Andreassen; Hellzen, Ove; Enmarker, Ingela

    2015-01-01

    Rural home nursing care is a neglected area in the research of palliative care offered to older cancer patients. Because access to specialized services is hampered by long distances and fragmented infrastructure, palliative care is often provided through standard home nursing services and delivered by general district nurses. This study aimed to illuminate the lived experience and to interpret the meaning of receiving home nursing care when being old and living with advanced cancer in a rural area in Norway. Narrative interviews were conducted with nine older persons, and a phenomenological hermeneutic approach was used to interpret the meaning of the lived experience. The analysis revealed three themes, each with subthemes: being content with what one gets, falling into place, and losing one's place. The phrase picking up the pieces was found useful to sum up the meaning of this lived experience. The three respective themes refer to how the pieces symbolize the remaining parts of life or available services in their environment, and how the older persons may see themselves as pieces or bricks in a puzzle. A strong place attachment (physical insideness, social insideness, and autobiographical insideness) is demonstrated by the informants in this study and suggests that the rural context may provide an advantageous healthcare environment. Its potential to be a source of comfort, security, and identity concurs with cancer patients' strong desire for being seen as unique persons. The study shows that district nurses play an essential role in the provision of palliative care for older rural patients. However, the therapeutic value of being in one's familiar landscape seems to depend on how homecare nurses manage to locate it and use it in a more or less person-centred manner. Communication skills and attentiveness to psychosocial aspects of patient care stand out as important attributes for nursing in this context. PMID:26362533

  16. Effects of ovum pick-up frequency and FSH stimulation: a retrospective study on seven years of beef cattle in vitro embryo production.

    PubMed

    De Roover, R; Feugang, J M N; Bols, P E J; Genicot, G; Hanzen, Ch

    2008-04-01

    The aim of this retrospective study was to compare the number of follicles, cumulus oocyte complexes (COCs) and cultured In Vitro Produced (IVP) embryos obtained from 1396 non-stimulated Ovum Pick-up (OPU) sessions on 81 donor animals in a twice weekly OPU scheme. Results were obtained from 640 sessions following FSH-LH superstimulation, on 112 donors subjected to OPU once every 2 weeks. The stimulation protocol started with the insertion of an ear implant containing 3 mg norgestomet (Crestar, Intervet, Belgium) 8 days before puncture (day -8). The dominant follicle was ablated by ultrasound-guided follicle puncture on day -6. On day -3 and day -2, cows were injected with FSH (Ovagen, ICP) twice daily (8 am to 8 pm), i.e. a total dose of 160 mug FSH and 40 mug LG per donor per stimulation cycle. Animals were punctured 48 h after the last FSH injection (day 0). Progesterone implants were removed the next day. Stimulated donor cows were treated with this protocol at 14-day intervals. Follicles were visualized with a Dynamic Imaging ultrasound scanner, equipped with a 6.5 MHz sectorial probe. Follicles were punctured with 55 cm long, 18 gauge needles at an aspiration pressure corresponding to a flow rate of 15 ml/min. Cumulus oocyte complexes were recovered and processed in a routine IVF set-up. Results demonstrate that, expressed per session, FSH stimulation prior to OPU increases production efficiency with significantly more follicles punctured and oocytes retrieved. However, when overall results during comparable 2-week periods are considered (four non-stimulated sessions vs one stimulated), more follicles are punctured and more oocytes are retrieved using the non-stimulated protocol. No significant differences in the number of cultured embryos could be detected, indicating that FSH/LH stimulation prior to OPU might have a positive effect on in vitro oocyte developmental competence as more embryos are cultured with less, presumably better-quality, oocytes. PMID

  17. Differential gene expression in cumulus oocyte complexes collected by ovum pick up from repeat breeder and normally fertile Holstein Friesian heifers.

    PubMed

    Puglisi, Roberto; Cambuli, Caterina; Capoferri, Rossana; Giannino, Laura; Lukaj, Aleksander; Duchi, Roberto; Lazzari, Giovanna; Galli, Cesare; Feligini, Maria; Galli, Andrea; Bongioni, Graziella

    2013-09-01

    The aim of this study was to establish whether perturbed gene expression during cumulus oocyte development causes repeat breeding in cattle. In this study, a repeat breeder was defined as a normal estrous cycling animal that did not become pregnant after three inseminations despite the absence of clinically detectable reproductive disorders. Transcripts of genes extracted from cumulus oocyte complexes (COC) that were collected from three repeat breeder and three normally fertile Holstein Friesian heifers were compared. Up to 40 COC were collected from each heifer by means of repeated sessions of ovum pick up in the absence of hormonal stimulation; immediately plunged into liquid nitrogen; and stored at -80°C until analysis. For each heifer, RNA was extracted from the pooled COC and hybridized on GeneChip(®) Bovine Gene Array (Affymetrix). Analysis of gene expression profiles of repeat breeder and control COC showed that 178 genes were differentially expressed (log2 fold change>1.5). Of these genes, 43 (24%) were up-regulated and 135 (76%) were down-regulated in repeat breeder relative to control heifers. This altered pattern of expression occurred in genes involved in several cellular biological processes and cellular components such as metabolism, angiogenesis, substrate/ion transport, regulation/signaling, cell adhesion and cytoskeleton. From these, 13 genes potentially involved in cumulus oocyte growth were subjected to validation by qRT-PCR and nine genes (annexin A1, ANXA1; lactoferrin, LTF; interferon stimulated exonuclease 20kDa, ISG20/HEM45; oxidized low density lipoprotein receptor 1, OLR1; fatty acid desaturase 2, FADS2; glutathione S-transferase A2 and A4, GSTA2 and GSTA4; glutathione peroxidase 1, GPX1; endothelin receptor type A, EDNRA) were confirmed to be differentially expressed. This study identified potential marker genes for fertility in dairy cattle. PMID:23911014

  18. Cherenkov Light-based Beam Profiling for Ultrarelativistic Electron Beams

    DOE PAGESBeta

    Adli, E.; Gessner, S. J.; Corde, S.; Hogan, M. J.; Bjerke, H. H.

    2015-02-09

    We describe a beam profile monitor design based on Cherenkov light emitted from a charged particle beam in an air gap. The main components of the profile monitor are silicon wafers used to reflect Cherenkov light onto a camera lens system. The design allows for measuring large beam sizes, with large photon yield per beam charge and excellent signal linearity with beam charge. Furthermore, the profile monitor signal is independent of the particle energy for ultrarelativistic particles. Different design and parameter considerations are discussed. A Cherenkov light-based profile monitor has been installed at the FACET User Facility at SLAC. Finally,more » we report on the measured performance of this profile monitor.« less

  19. Paradoxical effects of bovine somatotropin treatment on the ovarian follicular population and in vitro embryo production of lactating buffalo donors submitted to ovum pick-up.

    PubMed

    Ferraz, M L; Sá Filho, M F; Batista, E O S; Watanabe, Y F; Watanabe, M R; Dayan, A; Joaquim, D C; Accorsi, M R; Gimenes, L U; Vieira, L M; Baruselli, P S

    2015-03-01

    The aim of the present study was to evaluate the effect of bovine somatotropin (bST; 500mg) administration on lactating buffalo donors submitted to two different ovum pick-up (OPU) and in vitro embryo production schemes with a 7 or 14d intersession OPU interval. A total of 16 lactating buffalo cows were randomly assigned into one of four experimental groups according to the bST treatment (bST or No-bST) and the OPU intersession interval (7 or 14d) in a 2×2 factorial design (16 weeks of OPU sessions). The females submitted to OPU every 14d had a larger (P<0.001) number of ovarian follicles suitable for puncture (15.6±0.7 vs. 12.8±0.4) and an increased (P=0.004) number of cumulus-oocyte complexes (COCs) recovered (10.0±0.5 vs. 8.5±0.3) compared to the 7d interval group. However, a 7 or 14d interval between OPU sessions had no effect (P=0.34) on the number of blastocysts produced per OPU (1.0±0.1 vs. 1.3±0.2, respectively). In addition, bST treatment increased (P<0.001) the number of ovarian follicles suitable for puncture (15.3±0.5 vs. 12.1±0.4) but reduced the percentage (18.9% vs. 10.9%; P=0.009) and the number (1.4±0.2 vs. 0.8±0.1; P=0.003) of blastocysts produced per OPU session compared with the non-bST-treated buffaloes. In conclusion, the 14d interval between OPU sessions and bST treatment efficiently increased the number of ovarian follicles suitable for puncture. However, the OPU session interval had no effect on embryo production, and bST treatment reduced the in vitro blastocyst outcomes in lactating buffalo donors. PMID:25623138

  20. Prolonging the interval from ovarian hyperstimulation to laparoscopic ovum pick-up improves oocyte yield, quality, and developmental competence in goats.

    PubMed

    Abdullah, R B; Liow, S L; Rahman, A N M A; Chan, W K; Wan-Khadijah, W E; Ng, S C

    2008-09-15

    The objective was to evaluate the effect of the interval between ovarian hyperstimulation and laparoscopic ovum pick-up (LOPU) on quality and developmental competence of goat oocytes before and after in vitro maturation (IVM) and intracytoplasmic sperm injection (ICSI). Estrus was synchronized with an intravaginal insert containing 0.3g progesterone (CIDR) for 10d, combined with a luteolytic treatment of 125 microg cloprostenol 36 h prior to CIDR removal. Ovaries were hyperstimulated with 70 mg FSH and 500 IU hCG given im 36, 60, or 72 h prior to LOPU (n=15, 16, and 7 does, respectively). For these groups, oocyte retrieval rates (mean+/-S.E.M.) were 24.7+/-2.9, 54.5+/-4.7, and 82.8+/-4.6% (P<0.001), and the proportions of cumulus-oocyte complexes (COC) with more than five layers of cumulus cells were 29.7+/-8.3, 37.6+/-6.9, and 37.3+/-7.0% (P<0.001). The proportion of IVM oocytes was highest at 72 h (82.1+/-2.8%; P<0.05), with no significant difference between 36 and 60 h (57.3+/-8.9% and 69.0+/-8.4%). Cleavage rates of ICSI embryos were 4.2+/-4.2, 70.9+/-8.4, and 78.9+/-8.2% with LOPU 36, 60, and 72 h post FSH/hCG (P<0.01), with a lower proportion of Grade-A embryos (P<0.05) following LOPU at 36 h compared to 60 and 72 h (29.7+/-8.3%, 37.6+/-6.9%, and 37.3+/-7.0%). In summary, a prolonged interval from FSH/hCG to LOPU improved oocyte retrieval rate and oocyte quality. Therefore, under the present conditions, LOPU 60 or 72 h after FSH/hCG optimized yields of good-quality oocytes for IVM and embryo production in goats. PMID:18579196

  1. Ovarian Follicular Dynamics, Ovarian Follicular Growth, Oocyte Yield, In vitro Embryo Production and Repeated Oocyte Pick Up in Thai Native Heifers Undergoing Superstimulation

    PubMed Central

    Chasombat, J.; Nagai, T.; Parnpai, R.; Vongpralub, T.

    2013-01-01

    The objective of this study was to compare the effectiveness of the protocols for superstimulation of follicular growth in Thai native heifers. Heifers (n = 20) were randomly divided into four groups of five heifers/group. Heifers were given a single dose by i.m. administration of 100 mg Follicle Stimulating Hormone dissolved in polyvinylpyrrolidone (FSHp) at 24 h. Ovum pick up (OPU) occurred at 72 h (F24O72 protocol; Group 1) or 96 h (F24O96 protocol; Group 2), and at 36 h and OPU at 72 h (F36O72 protocol; Group 3) or 96 h (F36O96 protocol; Group 4) after follicular ablation. The dynamics of ovarian follicular growth were monitored by twice-daily ultrasonographic examinations. Blood sample collections were performed every 12 h after initiation of treatment for assessment of FSH, E2 and P4 profiles. All heifers were subjected to eight repeated sequential sessions of OPU. The follicular deviation commenced 24±5.32 h after follicular ablation in all groups. The circulatory FSH surged quickly from 24 to 36 h (>0.8 ng/ml) after follicular ablation and circulatory estrogen levels steadily increased from 36 h until OPU in all groups. At the end of the OPU sessions, the mean number of aspirated follicles/heifer/session in F36O72 protocol (Group 3) and F36O96 protocol (Group 4) were higher than in the two other groups (p<0.05). The number of cumulus-oocyte complexes (COCs), cleaved and day 8 blastocysts rates in the F36O72 protocol (Group 3) were higher than in the other groups (p<0.05). It can be concluded that a single dose i.m. administration of 100 mg FSHp at 36 h and OPU at 72 h after follicular ablation (F36O72 protocol; Group 3) was the most effective protocol for superstimulation of follicular growth for repeated OPU and subsequent in vitro embryo production in Thai native heifers. PMID:25049814

  2. Two different schemes of twice-weekly ovum pick-up in dairy heifers: effect on oocyte recovery and ovarian function.

    PubMed

    Petyim, S; Båge, R; Hallap, T; Bergqvist, A-S; Rodríguez-Martínez, H; Larsson, B

    2003-06-01

    The aim of the present study was to compare two different schemes of twice-weekly ovum pick-up (OPU), continuous (C) and discontinuous (DC), with special emphasis on differences in oocyte yield and quality, estrous cyclicity, ovarian dynamics, and progesterone production. Subsequent to characterization of their normal estrous cycles (pre-OPU period), eight dairy heifers were subjected to 4 months of twice-weekly OPU under two different schemes: the DC (OPU restricted to Days 0-12 of the cycle) and the C schemes. Effects of the two different schemes on oocyte yield, quality, and in vitro competence, together with effects on ovarian dynamics and progesterone production, were monitored. The mean numbers of punctured follicles and recovered oocytes per session were slightly higher (not significant (n.s.)) using the DC scheme, but in total, similar numbers of oocytes were obtained. The quality of the oocytes as well as cleavage rate after in vitro fertilization of the oocytes did not differ between the two OPU schemes. There was no influence of a corpus luteum (CL) producing progesterone on the oocyte yield and quality, whereas the presence of dominant follicles appeared to decrease the number of recovered ooctyes. During the pre-OPU period, all heifers showed normal cyclicity. In the DC scheme, the heifers showed regular and normal cyclic activity throughout the puncture period, with one to two complete follicular waves during the interval from the last OPU to the next estrus. In the C scheme, the heifers occasionally revealed cyclicities with irregular interestrous intervals and weaker signs of estrus. No complete follicular waves were seen during the OPU period in this scheme. The CL developed from the ovulation of the preovulatory follicles in the DC scheme showed similar characteristics to the CLs of the pre-OPU period; however, the CL-like structures from the puncture of follicles, in both the DC and the C schemes, revealed a shorter life span and inferior

  3. Beam-based alignment of the final focus test beam

    SciTech Connect

    Tenenbaum, P.; Burke, D.; Helm, R.; Irwin, J.; Raimondi, P.; Oide, K.; Floettmann, K.

    1995-12-01

    Beam-based alignment of quadrupole and sextupole magnets is crucial for the overall performance of linear collider final focus systems, especially for elimination of backgrounds and higher-order aberrations. At the Final Focus Test Beam (FFTB), alignment tolerances required for achieving the desired spot size are 100 microns in the horizontal and 30 microns in the vertical. Using a combination of independent magnet power supplies, hi-h-resolution stripline beam position monitors and precision magnet movers, the FFTB can be aligned to these tolerances in about 8 hours. Description of the algorithm, presentation of alignment results, and possible improvements to the system are discussed.

  4. Effect of repeated eCG treatments and ovum pick-up on ovarian response and oocyte recovery during early pregnancy in suckling beef cows.

    PubMed

    Aller, J F; Mucci, N C; Kaiser, G G; Callejas, S S; Alberio, R H

    2012-07-01

    This study was designed to evaluate in suckling early pregnant beef cows with and without eCG-pre-stimulation: (i) the influence of day gestation (from 40 to 101 days) and the consecutive eCG treatments on the follicular growth induced by means of ultrasound-guided transvaginal follicle ablation (FA; all follicles ≥ 5 mm) and the number and quality oocytes recovered by ovum pick-up (OPU) and (ii) the possible effects of repeated hormonal stimulation and FA/OPU on pregnancy outcome. Twelve suckling early pregnant Angus cows (40 days post fixed-time artificial insemination) were randomly assigned to each of two groups (n=6 group(-1)). Group 1 treatments included: FA (Day 0), eCG (1600 IU; Day 1) and OPU (Day 5). Group 2: as cited Group 1 with no eCG treatment. In both groups, OPU was repeated five times (Days 45, 59, 73, 87 and 101 of gestation). The numbers (mean ± SEM) of class II (5-9 mm; 4.3 ± 0.9) and class III (≥10 mm; 2.5 ± 0.4) follicles visualized per cow per OPU session in eCG-treated cows were greater (P<0.05) than for non-treated cows (0.9 ± 0.1 and 0.9 ± 0.1, respectively). In contrast, the number (mean ± SEM) of class I (<5mm) follicles per cow per OPU session was lower for cows with eCG treatment (2.8 ± 0.4) than for non-treated cows (5.7 ± 0.5). The mean number of aspirated follicles was not significantly different (P<0.05) between eCG-treated cows and non-treated cows at 45 and 59 days of pregnancy. However, the mean number of aspirated follicles was greater (P=0.03) in eCG-treated cows than non-treated cows from 73 day of pregnancy onwards. The numbers (mean ± SEM) of recovered oocytes and viable oocytes/cow/session were greater (P<0.05) for eCG-treated cows (2.2 ± 0.2 and 1.6 ± 0.4, respectively) than for non-treated cows (1.0 ± 0.2 and 0.9 ± 0.2, respectively). No donor pregnancies were lost either during or following OPU procedure. We can conclude that (1) eCG-treated pregnant suckled cows can be a source of oocytes for IVF at

  5. In vivo collection of follicular fluid and granulosa cells from individual follicles of different diameters in cattle by an adapted ovum pick-up system

    PubMed Central

    2013-01-01

    Background Most studies on granulosa cell (GC) function in cattle have been performed using GC and follicular fluid (FF) samples collected from slaughterhouse ovaries. Using this approach, the follicular developmental stage and functional status are unknown and indirectly inferred, limiting data interpretation. Ultrasound-guided follicle aspiration has previously been used to recover GC or FF samples, but this was mostly carried out in large follicles or pools of small follicles, without recording the efficiency of recovery. The present study was aimed at adapting and evaluating an ovum pick-up (OPU) system for the in vivo recovery of FF and GC from individual follicles of different diameters. Methods In the first trial, the losses of fluid inside the tubing system were calculated using a conventional or an adapted-OPU system. Blood plasma volumes equivalent to the amount of FF in follicles of different diameters were aspirated using a conventional OPU Teflon circuit. The OPU system was then adapted by connecting 0.25 mL straws to the circuit. A second trial evaluated the efficiency of FF recovery in vivo. Follicles ranging from 4.0 to 16.8 mm in diameter were aspirated individually using the conventional or adapted-OPU systems. A third trial assessed the in vivo recovery of GC and the subsequent amount of RNA obtained from the follicles of different diameters from Holstein and Gir cattle. Results In Trial I, the plasma recovery efficiency was similar (P > 0.05) for the volumes expected for 12 and 10 mm follicles, but decreased (P < 0.05) for smaller follicles (45.7+/−4.0%, 12.4+/−4.3% and 0.0+/−0.0% for 8, 6, and 4 mm follicles, respectively). Using the adaptation, the losses intrinsic to the aspiration system were similar for all follicle diameters. In Trial II, the expected and recovered volumes of FF were correlated (r = 0.89) and the efficiency of recovery was similar among follicles <12 mm, while larger follicles had a progressive increase

  6. Beam Breakup Effects in Dielectric Based Accelerators

    SciTech Connect

    Schoessow, P.; Kanareykin, A.; Jing, C.; Kustov, A.; Altmark, A.; Power, J. G.; Gai, W.

    2009-01-22

    The dynamics of the beam in structure-based wakefield accelerators leads to beam stability issues not ordinarily found in other machines. In particular, the high current drive beam in an efficient wakefield accelerator loses a large fraction of its energy in the decelerator structure, resulting in physical emittance growth, increased energy spread, and the possibility of head-tail instability for an off axis beam, all of which can lead to severe reduction of beam intensity. Beam breakup (BBU) effects resulting from parasitic wakefields provide a potentially serious limitation to the performance of dielectric structure based wakefield accelerators as well. We report on experimental and numerical investigation of BBU and its mitigation. The experimental program focuses on BBU measurements at the AWA facility in a number of high gradient and high transformer ratio wakefield devices. New pickup-based beam diagnostics will provide methods for studying parasitic wakefields that are currently unavailable. The numerical part of this research is based on a particle-Green's function beam breakup code we are developing that allows rapid, efficient simulation of beam breakup effects in advanced linear accelerators. The goal of this work is to be able to compare the results of detailed experimental measurements with the accurate numerical results and to design an external FODO channel for the control of the beam in the presence of strong transverse wakefields.

  7. Fast Beam-Based BPM Calibration

    SciTech Connect

    Bertsche, K.; Loos, H.; Nuhn, H.-D.; Peters, F.; /SLAC

    2012-10-15

    The Alignment Diagnostic System (ADS) of the LCLS undulator system indicates that the 33 undulator quadrupoles have extremely high position stability over many weeks. However, beam trajectory straightness and lasing efficiency degrade more quickly than this. A lengthy Beam Based Alignment (BBA) procedure must be executed every two to four weeks to re-optimize the X-ray beam parameters. The undulator system includes RF cavity Beam Position Monitors (RFBPMs), several of which are utilized by an automatic feedback system to align the incoming electron-beam trajectory to the undulator axis. The beam trajectory straightness degradation has been traced to electronic drifts of the gain and offset of the BPMs used in the beam feedback system. To quickly recover the trajectory straightness, we have developed a fast beam-based procedure to recalibrate the BPMs. This procedure takes advantage of the high-precision monitoring capability of the ADS, which allows highly repeatable positioning of undulator quadrupoles. This report describes the ADS, the position stability of the LCLS undulator quadrupoles, and some results of the new recovery procedure.

  8. Optical encoder based on a nondiffractive beam

    SciTech Connect

    Lutenberg, Ariel; Perez-Quintian, Fernando; Rebollo, Maria A

    2008-05-01

    Optical encoders are used in industrial and laboratory motion equipment to measure rotations and linear displacements. We introduce a design of an optical encoder based on a nondiffractive beam. We expect that the invariant profile and radial symmetry of the nondiffractive beam provide the design with remarkable tolerance to mechanical perturbations. We experimentally demonstrate that the proposed design generates a suitable output sinusoidal signal with low harmonic distortion. Moreover, we present a numerical model of the system based on the angular spectrum approximation whose predictions are in excellent agreement with the experimental results.

  9. QUADRUPOLE BEAM-BASED ALIGNMENT AT RHIC.

    SciTech Connect

    NIEDZIELA, J.; MONTAG, C.; SATOGATA, T.

    2005-05-16

    Successful implementation of a beam-based alignment algorithm, tailored to different types of quadrupoles at RHIC, provides significant benefits to machine operations for heavy ions and polarized protons. This algorithm was used to calibrate beam position monitor centers relative to interaction region quadrupoles to maximize aperture. This approach was also used to determine the optimal orbit through transition jump quadrupoles to minimize orbit changes during the transition jump for heavy ion acceleration. This paper provides background discussion and results from first measurements during the RHIC 2005 run.

  10. Liquid Crystal-based Beam Steering Technologies for NASA Applications

    NASA Technical Reports Server (NTRS)

    Pouch, John; Nguyen, Hung; Miranda, Felix; Bos, Philip; Lavrentovich, Oleg; Wang, Xinghua; Pishnyak, Oleg; Kreminska, Liubov; Golovin, Andrii

    2006-01-01

    Liquid crystal-based beam steering devices can provide electronic beam scanning to angles above 1 milliradian, sub-microradian beam pointing accuracy, as well as wave-front correction to maintain output optical beam quality. The liquid crystal technology effort will be summarized, and the potential application of the resulting devices to NASA space-based scenarios will be described.

  11. EDITORIAL: Negative ion based neutral beam injection

    NASA Astrophysics Data System (ADS)

    Hemsworth, R. S.

    2006-06-01

    It is widely recognized that neutral beam injection (NBI), i.e. the injection of high energy, high power, beams of H or D atoms, is a flexible and reliable system that has been the main heating system on a large variety of fusion devices, and NBI has been chosen as one of the three heating schemes of the International Tokomak Reactor (ITER). To date, all the NBI systems but two have been based on the neutralization (in a simple gas target) of positive hydrogen or deuterium ions accelerated to <100 keV/nucleon. Above that energy the neutralization of positive ions falls to unacceptably low values, and higher energy neutral beams have to be created by the neutralization of accelerated negative ions (in a simple gas target), as this remains high (approx60%) up to >1 MeV/nucleon. Unfortunately H- and D- are difficult to create, and the very characteristic that makes them attractive, the ease with which the electron is detached from the ion, means that it is difficult to create high concentrations or fluxes of them, and it is difficult to avoid substantial, collisional, losses in the extraction and acceleration processes. However, there has been impressive progress in negative ion sources and accelerators over the past decade, as demonstrated by the two pioneering, operational, multi-megawatt, negative ion based, NBI systems at LHD (180 keV, H0) and JT-60U (500 keV, D0), both in Japan. Nevertheless, the system proposed for ITER represents a substantial technological challenge as an increase is required in beam energy, to 1 MeV, D0, accelerated ion (D-) current, to 40 A, accelerated current density, 200 A m-2 of D-, and pulse length, to 1 h. At the Fourth IAEA Technical Meeting on Negative Ion Based Neutral Beam Injectors, hosted by the Consorzio RFX, Padova, Italy, 9-11 May 2005, the status of the R&D aimed at the realization of the injectors for ITER was presented. Because of the importance of this development to the success of the ITER project, participants at that

  12. Picking up Clues from the Discard Pile

    NASA Technical Reports Server (NTRS)

    2008-01-01

    As NASA's Phoenix Mars Lander excavates trenches, it also builds piles with most of the material scooped from the holes. The piles, like this one called 'Caterpillar,' provide researchers some information about the soil.

    On Aug. 24, 2008, during the late afternoon of the 88th Martian day after landing, Phoenix's Surface Stereo Imager took separate exposures through red, green and blue filters that have been combined into this approximately true-color image.

    This conical pile of soil is about 10 centimeters (4 inches) tall. The sources of material that the robotic arm has dropped onto the Caterpillar pile have included the 'Dodo' and ''Upper Cupboard' trenches and, more recently, the deeper 'Stone Soup' trench.

    Observations of the pile provide information, such as the slope of the cone and the textures of the soil, that helps scientists understand properties of material excavated from the trenches.

    For the Stone Soup trench in particular, which is about 18 centimeters (7 inches) deep, the bottom of the trench is in shadow and more difficult to observe than other trenches that Phoenix has dug. The Phoenix team obtained spectral clues about the composition of material from the bottom of Stone Soup by photographing Caterpillar through 15 different filters of the Surface Stereo Imager when the pile was covered in freshly excavated material from the trench.

    The spectral observation did not produce any sign of water-ice, just typical soil for the site. However, the bigger clumps do show a platy texture that could be consistent with elevated concentration of salts in the soil from deep in Stone Soup. The team chose that location as the source for a soil sample to be analyzed in the lander's wet chemistry laboratory, which can identify soluble salts in the soil.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  13. Optical encoder based on a nondiffractive beam

    NASA Astrophysics Data System (ADS)

    Lutenberg, A.; Perez Quintián, F.; Rebollo, M. A.

    2007-09-01

    Nowadays most industrial and laboratory motion measuring equipment makes use of optical encoders to measure rotation and linear displacements with sub-micrometrical resolution. In this work we introduce a new design of an optical encoder based on a non diffractive beam, a binary amplitude grating and a monolithic photodetector. Two theoretical models of the system are proposed and implemented to obtain numerical results. The performance of the design is also investigated through experimental measurements. Finally, the experimental results are compared with the models predictions.

  14. ALCBEAM - Neutral beam formation and propagation code for beam-based plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Bespamyatnov, I. O.; Rowan, W. L.; Liao, K. T.

    2012-03-01

    ALCBEAM is a new three-dimensional neutral beam formation and propagation code. It was developed to support the beam-based diagnostics installed on the Alcator C-Mod tokamak. The purpose of the code is to provide reliable estimates of the local beam equilibrium parameters: such as beam energy fractions, density profiles and excitation populations. The code effectively unifies the ion beam formation, extraction and neutralization processes with beam attenuation and excitation in plasma and neutral gas and beam stopping by the beam apertures. This paper describes the physical processes interpreted and utilized by the code, along with exploited computational methods. The description is concluded by an example simulation of beam penetration into plasma of Alcator C-Mod. The code is successfully being used in Alcator C-Mod tokamak and expected to be valuable in the support of beam-based diagnostics in most other tokamak environments. Program summaryProgram title: ALCBEAM Catalogue identifier: AEKU_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKU_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 66 459 No. of bytes in distributed program, including test data, etc.: 7 841 051 Distribution format: tar.gz Programming language: IDL Computer: Workstation, PC Operating system: Linux RAM: 1 GB Classification: 19.2 Nature of problem: Neutral beams are commonly used to heat and/or diagnose high-temperature magnetically-confined laboratory plasmas. An accurate neutral beam characterization is required for beam-based measurements of plasma properties. Beam parameters such as density distribution, energy composition, and atomic excited populations of the beam atoms need to be known. Solution method: A neutral beam is initially formed as an ion beam which is extracted from

  15. Optimization of beam configuration in laser fusion based on the laser beam pattern

    SciTech Connect

    Xu, Teng; Xu, Lixin; Wang, Anting; Gu, Chun; Wang, Shengbo; Liu, Jing; Wei, Ankun

    2013-12-15

    A simple method based on the laser beam pattern is proposed and numerically demonstrated to optimize a beam configuration for direct drive laser fusion. In this method, both the geometrical factor G{sub l} and the single beam factor B{sub l} are considered. By diminishing the product of B{sub l}·G{sub l}, the irradiation nonuniformity can be decreased to the order of 10{sup −5}. This optimization method can be applied on the design of irradiation systems for an arbitrary number of beams and any axially symmetric beam patterns.

  16. STED microscopy based on axially symmetric polarized vortex beams

    NASA Astrophysics Data System (ADS)

    Zhehai, Zhou; Lianqing, Zhu

    2016-03-01

    A stimulated emission depletion (STED) microscopy scheme using axially symmetric polarized vortex beams is proposed based on unique focusing properties of such kinds of beams. The concept of axially symmetric polarized vortex beams is first introduced, and the basic principle about the scheme is described. Simulation results for several typical beams are then shown, including radially polarized vortex beams, azimuthally polarized vortex beams, and high-order axially symmetric polarized vortex beams. The results indicate that sharper doughnut spots and thus higher resolutions can be achieved, showing more flexibility than previous schemes based on flexible modulation of both phase and polarization for incident beams. Project supported by the National Natural Science Foundation of China (Grant Nos. 61108047 and 61475021), the Natural Science Foundation of Beijing, China (Grant No. 4152015), the Program for New Century Excellent Talents in Universities of China (Grant No. NCET-13-0667), and the Top Young Talents Support Program of Beijing, China (Grant No. CIT&TCD201404113).

  17. Capacitive beam position monitors for the low-β beam of the Chinese ADS proton linac

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Wu, Jun-Xia; Zhu, Guang-Yu; Jia, Huan; Xue, Zong-Heng; Zheng, Hai; Xie, Hong-Ming; Kang, Xin-Cai; He, Yuan; Li, Lin; Denard, Jean Claude

    2016-02-01

    Beam Position Monitors (BPMs) for the low-β beam of the Chinese Accelerator Driven Subcritical system (CADS) Proton linac are of the capacitive pick-up type. They provide higher output signals than that of the inductive type. This paper will describe the design and tests of the capacitive BPM system for the low-β proton linac, including the pick-ups, the test bench and the read-out electronics. The tests done with an actual proton beam show a good agreement between the measurements and the simulations in the time domain. Supported by National Natural Science Foundation of China (11405240) and “Western Light” Talents Training Program of Chinese Academy of Sciences

  18. A compact spin-exchange optical pumping system for 3He polarization based on a solenoid coil, a VBG laser diode, and a cosine theta RF coil

    NASA Astrophysics Data System (ADS)

    Lee, Sungman; Kim, Jongyul; Moon, Myung Kook; Lee, Kye Hong; Lee, Seung Wook; Ino, Takashi; Skoy, Vadim R.; Lee, Manwoo; Kim, Guinyun

    2013-02-01

    For use as a neutron spin polarizer or analyzer in the neutron beam lines of the HANARO (High-flux Advanced Neutron Application ReactOr) nuclear research reactor, a 3He polarizer was designed based on both a compact solenoid coil and a VBG (volume Bragg grating) diode laser with a narrow spectral linewidth of 25 GHz. The nuclear magnetic resonance (NMR) signal was measured and analyzed using both a built-in cosine radio-frequency (RF) coil and a pick-up coil. Using a neutron transmission measurement, we estimated the polarization ratio of the 3He cell as 18% for an optical pumping time of 8 hours.

  19. Space chimp Enos returns to Patrick Air Force Base

    NASA Technical Reports Server (NTRS)

    1961-01-01

    Enos the chimpanzee that orbited the earth twice in a Mercury spacecraft arrives back at Patrick Air Force Base. Enos landed some 220 nautical miles south of Bermuda and was picked up up by the U.S.S. Stormes.

  20. Establishment of conditions for ovum pick up and IVM of jennies oocytes toward the setting up of efficient IVF and in vitro embryos culture procedures in donkey (Equus asinus).

    PubMed

    Goudet, Ghylène; Douet, Cécile; Kaabouba-Escurier, Aurore; Couty, Isabelle; Moros-Nicolás, Carla; Barrière, Philippe; Blard, Thierry; Reigner, Fabrice; Deleuze, Stefan; Magistrini, Michèle

    2016-07-15

    Most wild and domestic donkey breeds are currently endangered or threatened. Their preservation includes the creation of a Genome Resource Bank. Embryos cryopreservation allows the preservation of genetics from both male and female and is the fastest method to restore a breed. Because embryo production in vivo is limited in equids, our objective was to establish conditions for in vitro production of embryos in donkey using ovum pick up (OPU), IVM, IVF, and in vitro culture of zygotes. Donkey cumulus-oocyte complexes (COCs) were collected by transvaginal ultrasound-guided aspirations OPU in adult cyclic jennies and in vitro matured in tissue culture medium 199 supplemented with fetal calf serum and epidermal growth factor for 24, 30, 34, or 38 hours. They were preincubated with oviductal fluid for 30 minutes, coincubated with frozen-thawed donkey semen treated with procaine for 18 hours, and cultured for 30 hours in Dulbecco's Modified Eagle Medium-F12 supplemented with NaHCO3, fetal calf serum, and gentamycin. From the five OPU sessions, we collected 92 COCs in 193 follicles (48%) with an average of 4.2 COCs per jenny. All COCs were expanded after more than 24-hour IVM. At collection, jennies oocytes contained a germinal vesicle. Metaphase 1 oocytes were observed after 30-hour IVM and 44% were in metaphase 2 after 34-hour IVM. In our conditions, IVM of donkey oocytes was slower than IVM of equine oocytes and optimal duration for donkey oocytes IVM may be 34 hours. Only 15% of jennies oocytes contained two pronuclei after coincubation with donkey spermatozoa and none of them developed further after 48 hours post-IVF. Moreover, some parthenogenetic activation occurred. Thus, the treatment of donkey sperm with procaine may not be efficient for IVF. In conclusion, we established for the first time conditions for OPU in jennies with high recovery rates. We reported that IVM of jennies oocytes can produce 44% of metaphase 2 oocytes after 34 hours in culture

  1. Video-based beam position monitoring at CHESS

    NASA Astrophysics Data System (ADS)

    Revesz, Peter; Pauling, Alan; Krawczyk, Thomas; Kelly, Kevin J.

    2012-10-01

    CHESS has pioneered the development of X-ray Video Beam Position Monitors (VBPMs). Unlike traditional photoelectron beam position monitors that rely on photoelectrons generated by the fringe edges of the X-ray beam, with VBPMs we collect information from the whole cross-section of the X-ray beam. VBPMs can also give real-time shape/size information. We have developed three types of VBPMs: (1) VBPMs based on helium luminescence from the intense white X-ray beam. In this case the CCD camera is viewing the luminescence from the side. (2) VBPMs based on luminescence of a thin (~50 micron) CVD diamond sheet as the white beam passes through it. The CCD camera is placed outside the beam line vacuum and views the diamond fluorescence through a viewport. (3) Scatter-based VBPMs. In this case the white X-ray beam passes through a thin graphite filter or Be window. The scattered X-rays create an image of the beam's footprint on an X-ray sensitive fluorescent screen using a slit placed outside the beam line vacuum. For all VBPMs we use relatively inexpensive 1.3 Mega-pixel CCD cameras connected via USB to a Windows host for image acquisition and analysis. The VBPM host computers are networked and provide live images of the beam and streams of data about the beam position, profile and intensity to CHESS's signal logging system and to the CHESS operator. The operational use of VBPMs showed great advantage over the traditional BPMs by providing direct visual input for the CHESS operator. The VBPM precision in most cases is on the order of ~0.1 micron. On the down side, the data acquisition frequency (50-1000ms) is inferior to the photoelectron based BPMs. In the future with the use of more expensive fast cameras we will be able create VBPMs working in the few hundreds Hz scale.

  2. Simulation based analysis of laser beam brazing

    NASA Astrophysics Data System (ADS)

    Dobler, Michael; Wiethop, Philipp; Schmid, Daniel; Schmidt, Michael

    2016-03-01

    Laser beam brazing is a well-established joining technology in car body manufacturing with main applications in the joining of divided tailgates and the joining of roof and side panels. A key advantage of laser brazed joints is the seam's visual quality which satisfies highest requirements. However, the laser beam brazing process is very complex and process dynamics are only partially understood. In order to gain deeper knowledge of the laser beam brazing process, to determine optimal process parameters and to test process variants, a transient three-dimensional simulation model of laser beam brazing is developed. This model takes into account energy input, heat transfer as well as fluid and wetting dynamics that lead to the formation of the brazing seam. A validation of the simulation model is performed by metallographic analysis and thermocouple measurements for different parameter sets of the brazing process. These results show that the multi-physical simulation model not only can be used to gain insight into the laser brazing process but also offers the possibility of process optimization in industrial applications. The model's capabilities in determining optimal process parameters are exemplarily shown for the laser power. Small deviations in the energy input can affect the brazing results significantly. Therefore, the simulation model is used to analyze the effect of the lateral laser beam position on the energy input and the resulting brazing seam.

  3. Digital Beam Deflectors Based Partly on Liquid Crystals

    NASA Technical Reports Server (NTRS)

    Pouch, John J.; Miranda, Felix A.; Kreminska, Liubov; Pishnyak, Oleg; Golovin, Andrii; Winker, Bruce K.

    2007-01-01

    A digital beam deflector based partly on liquid crystals has been demonstrated as a prototype of a class of optical beam-steering devices that contain no mechanical actuators or solid moving parts. Such beam-steering devices could be useful in a variety of applications, including free-space optical communications, switching in fiber-optic communications, general optical switching, and optical scanning. Liquid crystals are of special interest as active materials in nonmechanical beam steerers and deflectors because of their structural flexibility, low operating voltages, and the relatively low costs of fabrication of devices that contain them.

  4. Applications of power beaming from space-based nuclear power stations. [Laser beaming to airplanes; microwave beaming to ground

    SciTech Connect

    Powell, J.R.; Botts, T.E.; Hertzberg, A.

    1981-01-01

    Power beaming from space-based reactor systems is examined using an advanced compact, lightweight Rotating Bed Reactor (RBR). Closed Brayton power conversion efficiencies in the range of 30 to 40% can be achieved with turbines, with reactor exit temperatures on the order of 2000/sup 0/K and a liquid drop radiator to reject heat at temperatures of approx. 500/sup 0/K. Higher RBR coolant temperatures (up to approx. 3000/sup 0/K) are possible, but gains in power conversion efficiency are minimal, due to lower expander efficiency (e.g., a MHD generator). Two power beaming applications are examined - laser beaming to airplanes and microwave beaming to fixed ground receivers. Use of the RBR greatly reduces system weight and cost, as compared to solar power sources. Payback times are a few years at present prices for power and airplane fuel.

  5. Arc-based smoothing of ion beam intensity on targets

    NASA Astrophysics Data System (ADS)

    Friedman, Alex

    2012-06-01

    By manipulating a set of ion beams upstream of a target, it is possible to arrange for a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy ("heavy-ion fusion"). Here, we consider an approach to such smoothing that is based on rapidly "wobbling" each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this is sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. It is found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.

  6. Arc-based smoothing of ion beam intensity on targets

    SciTech Connect

    Friedman, Alex

    2012-06-20

    Manipulating a set of ion beams upstream of a target, makes it possible to arrange a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy (“heavy-ion fusion”). Here, we consider an approach to such smoothing that is based on rapidly “wobbling” each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this is sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. We also found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.

  7. Arc-based smoothing of ion beam intensity on targets

    SciTech Connect

    Friedman, Alex

    2012-06-15

    By manipulating a set of ion beams upstream of a target, it is possible to arrange for a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy ('heavy-ion fusion'). Here, we consider an approach to such smoothing that is based on rapidly 'wobbling' each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this is sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. It is found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.

  8. Arc-based smoothing of ion beam intensity on targets

    DOE PAGESBeta

    Friedman, Alex

    2012-06-20

    Manipulating a set of ion beams upstream of a target, makes it possible to arrange a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy (“heavy-ion fusion”). Here, we consider an approach to such smoothing that is based on rapidly “wobbling” each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this ismore » sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. We also found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.« less

  9. Automatic learning-based beam angle selection for thoracic IMRT

    SciTech Connect

    Amit, Guy; Marshall, Andrea; Purdie, Thomas G. Jaffray, David A.; Levinshtein, Alex; Hope, Andrew J.; Lindsay, Patricia; Pekar, Vladimir

    2015-04-15

    Purpose: The treatment of thoracic cancer using external beam radiation requires an optimal selection of the radiation beam directions to ensure effective coverage of the target volume and to avoid unnecessary treatment of normal healthy tissues. Intensity modulated radiation therapy (IMRT) planning is a lengthy process, which requires the planner to iterate between choosing beam angles, specifying dose–volume objectives and executing IMRT optimization. In thorax treatment planning, where there are no class solutions for beam placement, beam angle selection is performed manually, based on the planner’s clinical experience. The purpose of this work is to propose and study a computationally efficient framework that utilizes machine learning to automatically select treatment beam angles. Such a framework may be helpful for reducing the overall planning workload. Methods: The authors introduce an automated beam selection method, based on learning the relationships between beam angles and anatomical features. Using a large set of clinically approved IMRT plans, a random forest regression algorithm is trained to map a multitude of anatomical features into an individual beam score. An optimization scheme is then built to select and adjust the beam angles, considering the learned interbeam dependencies. The validity and quality of the automatically selected beams evaluated using the manually selected beams from the corresponding clinical plans as the ground truth. Results: The analysis included 149 clinically approved thoracic IMRT plans. For a randomly selected test subset of 27 plans, IMRT plans were generated using automatically selected beams and compared to the clinical plans. The comparison of the predicted and the clinical beam angles demonstrated a good average correspondence between the two (angular distance 16.8° ± 10°, correlation 0.75 ± 0.2). The dose distributions of the semiautomatic and clinical plans were equivalent in terms of primary target volume

  10. Dynamic MEMS-based linear (1D) diffusers for laser beam homogenizing and beam shaping

    NASA Astrophysics Data System (ADS)

    Masson, J.; Bich, A.; Noell, W.; Voelkel, R.; Weible, K. J.; De Rooij, N. F.

    2009-08-01

    We present a dynamic laser beam shaper based on MEMS technology. We show a prototype of a dynamic diffuser made of single crystal silicon. A linearly deformable silicon micromembrane is used to diffuse a laser beam in one dimension. Resonance frequencies of the membrane can range from 1 kHz to 100 kHz. Diffusing angle can be tuned by adjusting the driving voltage. We measured a diffusing angle of 0.16° for an actuation voltage of 20 V.

  11. An electron beam profile instrument based on FBGs.

    PubMed

    Sporea, Dan; Stăncălie, Andrei; Becherescu, Nicu; Becker, Martin; Rothhardt, Manfred

    2014-01-01

    Along with the dose rate and the total irradiation dose measurements, the knowledge of the beam localization and the beam profile/energy distribution in the beam are parameters of interest for charged particle accelerator installations when they are used in scientific investigations, industrial applications or medical treatments. The transverse profile of the beam, its position, its centroid location, and its focus or flatness depend on the instrument operating conditions or on the beam exit setup. Proof-of-concept of a new type of charged particle beam diagnostics based on fiber Bragg gratings (FBGs) was demonstrated. Its operating principle relies on the measurement of the peak wavelength changes for an array of FBG sensors as function of the temperature following the exposure to an electron beam. Periodically, the sensor irradiation is stopped and the FBG are force cooled to a reference temperature with which the temperature influencing each sensor during beam exposure is compared. Commercially available FBGs, and FBGs written in radiation resistant optical fibers, were tested under electron beam irradiation in order to study their possible use in this application. PMID:25157554

  12. An Electron Beam Profile Instrument Based on FBGs

    PubMed Central

    Sporea, Dan; Stăncălie, Andrei; Becherescu, Nicu; Becker, Martin; Rothhardt, Manfred

    2014-01-01

    Along with the dose rate and the total irradiation dose measurements, the knowledge of the beam localization and the beam profile/energy distribution in the beam are parameters of interest for charged particle accelerator installations when they are used in scientific investigations, industrial applications or medical treatments. The transverse profile of the beam, its position, its centroid location, and its focus or flatness depend on the instrument operating conditions or on the beam exit setup. Proof-of-concept of a new type of charged particle beam diagnostics based on fiber Bragg gratings (FBGs) was demonstrated. Its operating principle relies on the measurement of the peak wavelength changes for an array of FBG sensors as function of the temperature following the exposure to an electron beam. Periodically, the sensor irradiation is stopped and the FBG are force cooled to a reference temperature with which the temperature influencing each sensor during beam exposure is compared. Commercially available FBGs, and FBGs written in radiation resistant optical fibers, were tested under electron beam irradiation in order to study their possible use in this application. PMID:25157554

  13. Ion beam analysis based on cellular nonlinear networks

    NASA Astrophysics Data System (ADS)

    Senger, V.; Tetzlaff, R.; Reichau, H.; Ratzinger, U.

    2011-07-01

    The development of a non- destructive measurement method for ion beam parameters has been treated in various projects. Although results are promising, the high complexity of beam dynamics has made it impossible to implement a real time process control up to now. In this paper we will propose analysing methods based on the dynamics of Cellular Nonlinear Networks (CNN) that can be implemented on pixel parallel CNN based architectures and yield satisfying results even at low resolutions.

  14. Recent progress in tailoring trap-based positron beams

    SciTech Connect

    Natisin, M. R.; Hurst, N. C.; Danielson, J. R.; Surko, C. M.

    2013-03-19

    Recent progress is described to implement two approaches to specially tailor trap-based positron beams. Experiments and simulations are presented to understand the limits on the energy spread and pulse duration of positron beams extracted from a Penning-Malmberg (PM) trap after the particles have been buffer-gas cooled (or heated) in the range of temperatures 1000 {>=} T {>=} 300 K. These simulations are also used to predict beam performance for cryogenically cooled positrons. Experiments and simulations are also presented to understand the properties of beams formed when plasmas are tailored in a PM trap in a 5 tesla magnetic field, then non-adiabatically extracted from the field using a specially designed high-permeability grid to create a new class of electrostatically guided beams.

  15. Dual-band relativistic backward wave oscillators based on a single beam and dual beams

    NASA Astrophysics Data System (ADS)

    Ting, Wang; Jian-de, Zhang; Bao-liang, Qian; Xiao-ping, Zhang

    2010-04-01

    Two types of relativistic backward wave oscillators (RBWOs) used to produce dual-band microwaves are proposed and investigated by use of the particle-in-cell (PIC) simulation code KARAT [V. P. Tarakanov, User's Manual for Code Karat (Berkeley Research Associates, Springfield, VA, 1992)]. The first type of RBWO, for generation of C-band and X-band microwaves, is designed based on a single beam and a sectioned structure. With an electron beam of 650 keV and 5.0 kA guided by a magnetic field of 2.0 T, an average power of 380 MW with a total power conversion efficiency of 11.7% is obtained and the frequencies are 5.48 and 9.60 GHz, respectively. By changing the distance between the two sections, single-band oscillations are realized with higher power conversion efficiency than that of the dual-band oscillation. The second type, based on a coaxial structure and dual parallel annular beams, is a dual-band RBWO designed with separated beam-wave interaction regions for generation of C-band and X-band microwaves. With a dual beam of 650 keV and 11.8 kA (the outer beam current is 6.4 kA and inner beam current is 5.4 kA) guided by a magnetic field of 2.0 T, an output power of 1400 MW with a total power conversion efficiency of 18.3% is generated and the frequencies are 4.60 and 8.40 GHz, respectively. PIC simulations demonstrate that the two beam-wave interaction regions operate independently. The two types of dual-band RBWO are also compared and analyzed.

  16. Formation mechanisms and optimization of trap-based positron beams

    NASA Astrophysics Data System (ADS)

    Natisin, M. R.; Danielson, J. R.; Surko, C. M.

    2016-02-01

    Described here are simulations of pulsed, magnetically guided positron beams formed by ejection from Penning-Malmberg-style traps. In a previous paper [M. R. Natisin et al., Phys. Plasmas 22, 033501 (2015)], simulations were developed and used to describe the operation of an existing trap-based beam system and provided good agreement with experimental measurements. These techniques are used here to study the processes underlying beam formation in more detail and under more general conditions, therefore further optimizing system design. The focus is on low-energy beams (˜eV) with the lowest possible spread in energies (<10 meV), while maintaining microsecond pulse durations. The simulations begin with positrons trapped within a potential well and subsequently ejected by raising the bottom of the trapping well, forcing the particles over an end-gate potential barrier. Under typical conditions, the beam formation process is intrinsically dynamical, with the positron dynamics near the well lip, just before ejection, particularly crucial to setting beam quality. In addition to an investigation of the effects of beam formation on beam quality under typical conditions, two other regimes are discussed; one occurring at low positron temperatures in which significantly lower energy and temporal spreads may be obtained, and a second in cases where the positrons are ejected on time scales significantly faster than the axial bounce time, which results in the ejection process being essentially non-dynamical.

  17. Beam-based Feedback for the Linac Coherent Light Source

    SciTech Connect

    Fairley, D.; Allison, S.; Chevtsov, S.; Chu, P.; Decker, F.J.; Emma, P.; Frisch, J.; Himel, T.; Kim, K.; Krejcik, P.; Loos, H.; Lahey, T.; Natampalli, P.; Peng, S.; Rogind, D.; Shoaee, H.; Straumann, T.; Williams, E.; White, G.; Wu, J.; Zelazney, M.; /SLAC

    2010-02-11

    Beam-based feedback control loops are required by the Linac Coherent Light Source (LCLS) program in order to provide fast, single-pulse stabilization of beam parameters. Eight transverse feedback loops, a 6 x 6 longitudinal feedback loop, and a loop to maintain the electron bunch charge were successfully prototyped in MATLAB for the LCLS, and have been maintaining stability of the LCLS electron beam at beam rates up to 30Hz. In the final commissioning phase of LCLS the beam will be operating at up to 120Hz. In order to run the feedback loops at beam rate, the feedback loops will be implemented in EPICS IOCs with a dedicated ethernet multi-cast network. This paper will discuss the design of the beam-based Fast Feedback System for LCLS. Topics include MATLAB feedback prototyping, algorithm for 120Hz feedback, network design for fast data transport, actuator and sensor design for single-pulse control and sensor readback, and feedback configuration and runtime control.

  18. Simulation Studies of Beam-Beam Effects of a Ring-Ring Electron-Ion Collider Based on CEBAF

    SciTech Connect

    Yuhong Zhang,Ji Qiang

    2009-05-01

    The collective beam-beam effect can potentially cause a rapid growth of beam sizes and reduce the luminosity of a collider to an unacceptably low level. The ELIC, a proposed ultra high luminosity electron-ion collider based on CEBAF, employs high repetition rate crab crossing colliding beams with very small bunch transverse sizes and very short bunch lengths, and collides them at up to 4 interaction points with strong final focusing. All of these features can make the beam-beam effect challenging. In this paper, we present simulation studies of the beam-beam effect in ELIC using a self-consistent strong-strong beam-beam simulation code developed at Lawrence Berkeley National Laboratory. This simulation study is used for validating the ELIC design and for searching for an optimal parameter set.

  19. Resonant microphone based on laser beam deflection

    NASA Astrophysics Data System (ADS)

    Roark, Kevin; Diebold, Gerald J.

    2004-07-01

    A microphone consisting of a flexible membrane coupled to a Helmholtz resonator can be constructed to have a resonance at a specific frequency making it, unlike conventional broadband microphones, a frequency selective detector of sound. The present device uses a laser beam reflected from the membrane and directed onto a split photodiode to record the motion of the membrane. Since the microphone has a lightly damped resonance, both the thermal noise fluctuations in the displacement of the membrane from its equilibrium position and the response of the microphone to sound at the resonance frequency are large. The large amplitude of both the signal and the noise fluctuations means that effect of amplifier noise on the microphone's sensitivity is diminished relative to that in broadband microphones. Applications of the microphone include photoacoustic detection of gases employing low power lasers.

  20. Study of Nuclei far From Stability by Using the CHIMERA 4{pi} Detector and Radioactive Beams at LNS

    SciTech Connect

    Cardella, G.; De Filippo, E.; Pagano, A.; Papa, M.; Pirrone, S.; Verde, G.; Amorini, F.; Anzalone, A.; Maiolino, C.; Auditore, L.; Loria, D.; Trifiro, A.; Trimarchi, M.; Cavallaro, S.; Lombardo, I.; Porto, F.; Rizzo, F.; Russotto, P.; Chatterjee, M. B.; Geraci, E.

    2009-08-26

    At LNS are available radioactive beams at tandem and intermediate energies provided respectively by the EXCYT and by the fragmentation FRIBS facilities. Using these beams, and the 4{pi} detector CHIMERA, we want to study excitation and decay of resonances in light exotic nuclei populated with pick-up stripping and other reaction mechanisms. Some preliminary results obtained with stable and unstable beams are reported.

  1. Quadrupole Beam-Based Alignment in the RHIC Interaction Regions

    SciTech Connect

    T. Satogata, J. Ziegler

    2011-03-01

    Continued beam-based alignment (BBA) efforts have provided significant benefit to both heavy ion and polarized proton operations at RHIC. Recent studies demonstrated previously unknown systematic beam position monitor (BPM) offset errors and produced accurate measurements of individual BPM offsets in the experiment interaction regions. Here we describe the algorithm used to collect and analyze data during the 2010 and early 2011 RHIC runs and the results of these measurements.

  2. Laser-based profile and energy monitor for H beams

    SciTech Connect

    Connolly,R.; Alessi, J.; Bellavia, S.; Dawson, C.; Degen, C.; Meng, W.; Raparia, D.; Russo, T.; Tsoupas, N.

    2008-09-29

    A beam profile and energy monitor for H{sup -} beams based on laser photoneutralization was built at Brookhaven National Laboratory (BNL)* for use on the High Intensity Neutrino Source (HMS) at Fermilab. An H{sup -} ion has a first ionization potential of 0.75eV and can be neutralized by light from a Nd:YAG laser ({lambda}=1064nm). To measure beam profiles, a narrow laser beam is stepped across the ion beam, removing electrons from the portion of the H{sup -} beam intercepted by the laser. These electrons are channeled into a Faraday cup by a curved axial magnetic field. To measure the energy distribution of the electrons, the laser position is fixed and the voltage on a screen in front of the Faraday cup is raised in small steps. We present a model which reproduces the measured energy spectrum from calculated beam energy and space-charge fields. Measurements are reported from experiments in the BNL linac MEBT at 750keV.

  3. Design of a neutrino source based on beta beams

    NASA Astrophysics Data System (ADS)

    Wildner, E.; Hansen, C.; Benedetto, E.; Jensen, E.; Stora, T.; Mendonca, T. Melo; Vlachoudis, V.; Bouquerel, E.; Marie-Jeanne, M.; Balint, P.; Fourel, C.; Giraud, J.; Jacob, J.; Lamy, T.; Latrasse, L.; Sortais, P.; Thuillier, T.; Mitrofanov, S.; Loiselet, M.; Keutgen, Th.; Delbar, Th.; Debray, F.; Trophime, C.; Veys, S.; Daversin, C.; Zorin, V.; Izotov, I.; Skalyga, V.; Chancé, A.; Payet, J.; Burt, G.; Dexter, A. C.; Kravchuk, V. L.; Marchi, T.; Cinausero, M.; Gramegna, F.; De Angelis, G.; Prete, G.; Collazuol, G.; Mezzetto, M.; Vardaci, E.; Di Nitto, A.; Brondi, A.; La Rana, G.; Moro, R.; Palladino, V.; Gelli, N.; Mazzocco, M.; Signorini, C.; Hirsh, T. Y.; Hass, M.; Berkovits, D.; Stahl, A.; Schaumann, M.; Wehner, J.

    2014-07-01

    "Beta beams" produce collimated pure electron (anti)neutrino beams by accelerating beta active ions to high energies and having them decay in a racetrack shaped storage ring of 7 km circumference, the decay ring. EUROnu beta beams are based on CERN infrastructures and existing machines. Using existing machines may be an advantage for the cost evaluation, but will also constrain the physics performance. The isotope pair of choice for the beta beam is He6 and Ne18. However, before the EUROnu studies one of the required isotopes, Ne18, could not be produced in rates that satisfy the needs for physics of the beta beam. Therefore, studies of alternative beta emitters, Li8 and B8, with properties interesting for a beta beam have been proposed and have been studied within EUROnu. These alternative isotopes could be produced by using a small storage ring, in which the beam traverses a target, creating the Li8 and B8 isotopes. This production ring, the injection linac and the target system have been evaluated. Measurements of the cross section of the reactions to produce the beta beam isotopes show interesting results. A device to collect the produced isotopes from the target has been developed and tested. However, the yields of Li8 and B8, using the production ring for production of Li8 and B8, is not yet, according to simulations, giving the rates of isotopes that would be needed. Therefore, a new method of producing the Ne18 isotope has been developed and tested giving good production rates. A 60 GHz ECRIS prototype, the first in the world, was developed and tested for ion production with contributions from EUROnu. The decay ring lattices for the Li8 and B8 have been developed and the lattice for He6 and Ne18 has been optimized to ensure the high intensity ion beam stability.

  4. Microfabricated cantilever-based detector for molecular beam experiments

    NASA Astrophysics Data System (ADS)

    Bachels, T.; Schäfer, R.

    1998-11-01

    A low cost detector for particles in molecular beam experiments is presented which can easily be mounted in a molecular beam apparatus. The detector is based on microfabricated cantilevers, which can be employed either as single sensors or as sensor arrays. The single cantilever technique has been used to measure the absolute number of atoms coming out of a pulsed laser vaporization cluster source. The particles are detected by the shift of the thermally excited resonance frequency of the cantilever due to the cluster deposition. We have determined with the single cantilever the ratio of neutral to ionized clusters and we have investigated the cluster generation at different source conditions. In addition to this, a microfabricated cantilever array has been used to measure molecular beam profiles, which opens new possibilities for molecular beam deflection experiments.

  5. Transformer ratio improvement for beam based plasma accelerators

    SciTech Connect

    O'Shea, Brendan; Rosenzweig, James; Barber, Samuel; Fukasawa, Atsushi; Williams, Oliver; Muggli, Patric; Yakimenko, Vitaly; Kusche, Karl

    2012-12-21

    Increasing the transformer ratio of wakefield accelerating systems improves the viability of present novel accelerating schemes. The use of asymmetric bunches to improve the transformer ratio of beam based plasma systems has been proposed for some time[1, 2] but suffered from lack appropriate beam creation systems. Recently these impediments have been overcome [3, 4] and the ability now exists to create bunches with current profiles shaped to overcome the symmetric beam limit of R {<=} 2. We present here work towards experiments designed to measure the transformer ratio of such beams, including theoretical models and simulations using VORPAL (a 3D capable PIC code) [5]. Specifically we discuss projects to be carried out in the quasi-nonlinear regime [6] at the UCLA Neptune Laboratory and the Accelerator Test Facility at Brookhaven National Lab.

  6. Ground Base Skylab Electron Beam Welds in Tantalum

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Comparison of ground-based (left) and Skylab (right) electron beam welds in pure tantalum (Ta) (10X magnification). Residual votices left behind in the ground-based sample after the electron beam passed were frozen into the grain structure. These occurred because of the rapid cooling rate at the high temperature. Although the thermal characteristics and electron beam travel speeds were comparable for the skylab sample, the residual vortices were erased in the grain structure. This may have been due to the fact that final grain size of the solidified material was smaller in the Skylab sample compared to the ground-based sample. The Skylab sample was processed in the M512 Materials Processing Facility (MPF) during Skylab SL-2 Mission. Principal Investigator was Richard Poorman.

  7. Control of Space-Based Electron Beam Free Form Fabrication

    NASA Technical Reports Server (NTRS)

    Seifzer. W. J.; Taminger, K. M.

    2007-01-01

    Engineering a closed-loop control system for an electron beam welder for space-based additive manufacturing is challenging. For earth and space based applications, components must work in a vacuum and optical components become occluded with metal vapor deposition. For extraterrestrial applications added components increase launch weight, increase complexity, and increase space flight certification efforts. Here we present a software tool that closely couples path planning and E-beam parameter controls into the build process to increase flexibility. In an environment where data collection hinders real-time control, another approach is considered that will still yield a high quality build.

  8. Individual information beam broadcasting system using a PAL-SLM based CGH beam former for the location based information services

    NASA Astrophysics Data System (ADS)

    Osawa, Shunichi; Itoh, Hideo; Nakamura, Yoshiyuki; Nishimura, Takuichi; Lin, Xin; Tokuda, Masamitsu

    2006-01-01

    As an implementation of ubiquitous information service environments, we have been researching location-based information service systems at indoor and short distance area. The system should provide adequate information services, which fit the user's attributes, such as language, knowledge level and the volume of information, what is so-called "Right now, Here, and for Me" information services. Keeping privacy and security of the user is an important issue. Spatial optical communication technique is used for the system because the technique is easy to implement a location- and direction-based communication system. Information broadcasting in an area can be realized by an omnidirectional modulated light emission. However, the omnidirectional beam causes spill out of secure information to others, and has lower energy conservation than a focused beam communication. In this paper, a new spatial optical information broadcasting system, which can focus modulated beams only to intended users. CGH (Computer Generated Hologram) technique on a SLM (Spatial Light Modulator) is proposed and demonstrated. The system is composed of a PAL-SLM (Parallel Aligned Nematic Liquid Crystal Spatial Light Modulator), an eye-safe semiconductor laser or a semiconductor laser pumped YAG laser for the beam emitter, and an infrared video camera with an infrared LED illuminator for user locator. Experimental results of beam deflecting characteristics are described on beam uniformity, deflecting angle and the enhancement, communication characteristics, and real time tracking of user with a corner-reflecting sheet.

  9. Beam Diagnostics Based on AC Modulation of System Parameters

    SciTech Connect

    Michael Tiefenback

    2004-11-10

    To improve the performance of operating accelerators, quantities such as lattice functions, beam transfer functions, betatron frequencies, etc, can be measured turn by turn with beam position monitors or from difference measurements using step changes in system parameters. Spectral measurements in closed orbit machines provide accurate values for some properties. But for open-ended systems and some measurements in closed-orbit machines, periodic modulation can be very useful for obtaining information about the beam line. Using examples from existing machines, we compare and contrast beam based modulation techniques and step function or passive measurements. For example, large amplitude dipole modulation in rings can be used in dedicated exploration of nonlinear optical properties without beam degradation, even allowing for tune spread effects. Low-level modulation can provide real-time system monitoring with no adverse effect on beam users. Examples considered include fully resonant dipole modulation in storage rings such as RHIC (hadrons) and PEP-II (electrons), and the continuous low-level modulation used in the CEBAF recirculating electron linac for real-time feedback to improve availability.

  10. Experimental demonstration of dielectric structure based two beam acceleration.

    SciTech Connect

    Gai, W.; Conde, M. E.; Konecny, R.; Power, J. G.; Schoessow, P.; Sun, X.; Zou, P.

    2000-11-28

    We report on the experimental results of the dielectric based two beam accelerator (step-up transformer). By using a single high charge beam, we have generated and extracted a high power RF pulse from a 7.8 GHz primary dielectric structure and then subsequently transferred to a second accelerating structure with higher dielectric constant and smaller transverse dimensions. We have measured the energy change of a second (witness) beam passing through the acceleration stage. The measured gradient is >4 times the deceleration gradient. The detailed experiment of set-up and results of the measurements are dimmed. Future plans for the development of a 100 MeV demonstration accelerator based on this technique is presented.

  11. Beam based alignment of C-shaped quadrupole magnets

    SciTech Connect

    Portmann, G.; Robin, D.

    1998-06-01

    Many storage rings have implemented a method of finding the positional offset between the electrical center of the beam position monitors (BPM) and the magnetic center of the adjacent quadrupole magnets. The algorithm for accomplishing this is usually based on modulating the current in the quadrupole magnet and finding the beam position that minimizes the orbit perturbation. When the quadrupole magnet is C-shaped, as it is for many light sources, the modulation method can produce an erroneous measurement of the magnetic center in the horizontal plane. When the current in a C-shaped quadrupole is changed, there is an additional dipole component in the vertical field. Due to nonlinearities in the hysteresis cycle of the C-magnet geometry, the beam-based alignment technique at the Advanced Light Source (ALS) deviated horizontally by .5 mm from the actual magnetic center. By modifying the technique, the offsets were measured to an accuracy of better than 50 {micro}m.

  12. Accelerator Based Neutron Beams for Neutron Capture Therapy

    SciTech Connect

    Yanch, Jacquelyn C.

    2003-04-11

    The DOE-funded accelerator BNCT program at the Massachusetts Institute of Technology has resulted in the only operating accelerator-based epithermal neutron beam facility capable of generating significant dose rates in the world. With five separate beamlines and two different epithermal neutron beam assemblies installed, we are currently capable of treating patients with rheumatoid arthritis in less than 15 minutes (knee joints) or 4 minutes (finger joints) or irradiating patients with shallow brain tumors to a healthy tissue dose of 12.6 Gy in 3.6 hours. The accelerator, designed by Newton scientific Incorporated, is located in dedicated laboratory space that MIT renovated specifically for this project. The Laboratory for Accelerator Beam Applications consists of an accelerator room, a control room, a shielded radiation vault, and additional laboratory space nearby. In addition to the design, construction and characterization of the tandem electrostatic accelerator, this program also resulted in other significant accomplishments. Assemblies for generating epithermal neutron beams were designed, constructed and experimentally evaluated using mixed-field dosimetry techniques. Strategies for target construction and target cooling were implemented and tested. We demonstrated that the method of submerged jet impingement using water as the coolant is capable of handling power densities of up to 6 x 10(sup 7) W/m(sup 2) with heat transfer coefficients of 10(sup 6)W/m(sup 2)-K. Experiments with the liquid metal gallium demonstrated its superiority compared with water with little effect on the neutronic properties of the epithermal beam. Monoenergetic proton beams generated using the accelerator were used to evaluate proton RBE as a function of LET and demonstrated a maximum RBE at approximately 30-40 keV/um, a finding consistent with results published by other researchers. We also developed an experimental approach to biological intercomparison of epithermal beams and

  13. Induced base transistor fabricated by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Chang, C.-Y.; Liu, W. C.; Jame, M. S.; Wang, Y. H.; Luryi, S.

    1986-09-01

    A novel three-terminal hot-electron device, the induced base transistor (IBT), has been fabricated by molecular beam epitaxy. Two-dimensional electron gas induced by the applied collector field in an undoped GaAs quantum well is used as the base of the IBT. The common-base current gain alpha has been achieved as high as 0.96 under a collector bias of 2.5 V and an emitter current of 3 mA.

  14. Sound beam manipulation based on temperature gradients

    SciTech Connect

    Qian, Feng; Quan, Li; Liu, Xiaozhou Gong, Xiufen

    2015-10-28

    Previous research with temperature gradients has shown the feasibility of controlling airborne sound propagation. Here, we present a temperature gradients based airborne sound manipulation schemes: a cylindrical acoustic omnidirectional absorber (AOA). The proposed AOA has high absorption performance which can almost completely absorb the incident wave. Geometric acoustics is used to obtain the refractive index distributions with different radii, which is then utilized to deduce the desired temperature gradients. Since resonant units are not applied in the scheme, its working bandwidth is expected to be broadband. The scheme is temperature-tuned and easy to realize, which is of potential interest to fields such as noise control or acoustic cloaking.

  15. Sound beam manipulation based on temperature gradients

    NASA Astrophysics Data System (ADS)

    Qian, Feng; Quan, Li; Liu, Xiaozhou; Gong, Xiufen

    2015-10-01

    Previous research with temperature gradients has shown the feasibility of controlling airborne sound propagation. Here, we present a temperature gradients based airborne sound manipulation schemes: a cylindrical acoustic omnidirectional absorber (AOA). The proposed AOA has high absorption performance which can almost completely absorb the incident wave. Geometric acoustics is used to obtain the refractive index distributions with different radii, which is then utilized to deduce the desired temperature gradients. Since resonant units are not applied in the scheme, its working bandwidth is expected to be broadband. The scheme is temperature-tuned and easy to realize, which is of potential interest to fields such as noise control or acoustic cloaking.

  16. MEMS-based diffractive optical-beam-steering technology

    NASA Astrophysics Data System (ADS)

    Winick, David A.; Duewer, Bruce E.; Chaudhury, Som; Wilson, John M.; Tucker, John; Eksi, Umut; Franzon, Paul D.

    1998-03-01

    This paper presents some results from phase-1 research into developing a beam steerer based on micro-mechanical diffractive elements. The position of these elements is electrostatically controlled, to allow dynamic programming of a 2D phase function. Feasibility prototypes were constructed in the MUMPs polysilicon surface micromachine process.

  17. Comparison of Beam-Based Alignment Algorithms for the ILC

    SciTech Connect

    Smith, J.C.; Gibbons, L.; Patterson, J.R.; Rubin, D.L.; Sagan, D.; Tenenbaum, P.; /SLAC

    2006-03-15

    The main linac of the International Linear Collider (ILC) requires more sophisticated alignment techniques than those provided by survey alone. Various Beam-Based Alignment (BBA) algorithms have been proposed to achieve the desired low emittance preservation. Dispersion Free Steering, Ballistic Alignment and the Kubo method are compared. Alignment algorithms are also tested in the presence of an Earth-like stray field.

  18. National negative-ion-based neutral-beam development plan

    SciTech Connect

    Cooper, W.S.; Pyle, R.V.

    1983-08-01

    The plan covers facilities required, program milestones, and decision points. It includes identification of applications, experiments, theoretical research areas, development of specific technologies and reactor development and demonstration facilities required to bring about the successful application of negative-ion-based neutral beams. Particular emphasis is placed on those activities leading to use on existing plasma confinement experiments or their upgrades.

  19. Nonlinear transmission line based electron beam driver.

    PubMed

    French, David M; Hoff, Brad W; Tang, Wilkin; Heidger, Susan; Allen-Flowers, Jordan; Shiffler, Don

    2012-12-01

    Gated field emission cathodes can provide short electron pulses without the requirement of laser systems or cathode heating required by photoemission or thermionic cathodes. The large electric field requirement for field emission to take place can be achieved by using a high aspect ratio cathode with a large field enhancement factor which reduces the voltage requirement for emission. In this paper, a cathode gate driver based on the output pulse train from a nonlinear transmission line is experimentally demonstrated. The application of the pulse train to a tufted carbon fiber field emission cathode generates short electron pulses. The pulses are approximately 2 ns in duration with emission currents of several mA, and the train contains up to 6 pulses at a frequency of 100 MHz. Particle-in-cell simulation is used to predict the characteristic of the current pulse train generated from a single carbon fiber field emission cathode using the same technique. PMID:23277977

  20. Nonlinear transmission line based electron beam driver

    NASA Astrophysics Data System (ADS)

    French, David M.; Hoff, Brad W.; Tang, Wilkin; Heidger, Susan; Allen-Flowers, Jordan; Shiffler, Don

    2012-12-01

    Gated field emission cathodes can provide short electron pulses without the requirement of laser systems or cathode heating required by photoemission or thermionic cathodes. The large electric field requirement for field emission to take place can be achieved by using a high aspect ratio cathode with a large field enhancement factor which reduces the voltage requirement for emission. In this paper, a cathode gate driver based on the output pulse train from a nonlinear transmission line is experimentally demonstrated. The application of the pulse train to a tufted carbon fiber field emission cathode generates short electron pulses. The pulses are approximately 2 ns in duration with emission currents of several mA, and the train contains up to 6 pulses at a frequency of 100 MHz. Particle-in-cell simulation is used to predict the characteristic of the current pulse train generated from a single carbon fiber field emission cathode using the same technique.

  1. Nonlinear transmission line based electron beam driver

    SciTech Connect

    French, David M.; Hoff, Brad W.; Tang Wilkin; Heidger, Susan; Shiffler, Don; Allen-Flowers, Jordan

    2012-12-15

    Gated field emission cathodes can provide short electron pulses without the requirement of laser systems or cathode heating required by photoemission or thermionic cathodes. The large electric field requirement for field emission to take place can be achieved by using a high aspect ratio cathode with a large field enhancement factor which reduces the voltage requirement for emission. In this paper, a cathode gate driver based on the output pulse train from a nonlinear transmission line is experimentally demonstrated. The application of the pulse train to a tufted carbon fiber field emission cathode generates short electron pulses. The pulses are approximately 2 ns in duration with emission currents of several mA, and the train contains up to 6 pulses at a frequency of 100 MHz. Particle-in-cell simulation is used to predict the characteristic of the current pulse train generated from a single carbon fiber field emission cathode using the same technique.

  2. Biomolecule Analogues 2-Hydroxypyridine and 2-Pyridone Base Pairing on Ice Nanoparticles.

    PubMed

    Rubovič, Peter; Pysanenko, Andriy; Lengyel, Jozef; Nachtigallová, Dana; Fárník, Michal

    2016-07-14

    Ice nanoparticles (H2O)N, N ≈ 450 generated in a molecular beam experiment pick up individual gas phase molecules of 2-hydroxypyridine and 2-pyridone (HP) evaporated in a pickup cell at temperatures between 298 and 343 K. The mass spectra of the doped nanoparticles show evidence for generation of clusters of adsorbed molecules (HP)n up to n = 8. The clusters are ionized either by 70 eV electrons or by two photons at 315 nm (3.94 eV). The two ionization methods yield different spectra, and their comparison provides an insight into the neutral cluster composition, ionization and intracluster ion-molecule reactions, and cluster fragmentation. Quite a few molecules were reported not to coagulate on ice nanoparticles previously. The (HP)n cluster generation on ice nanoparticles represents the first evidence for coagulating of molecules and cluster formation on free ice nanoparticles. For comparison, we investigate the coagulation of HP molecules picked up on large clusters ArN, N ≈ 205, and also (HP)n clusters generated in supersonic expansions with Ar buffer gas. This comparison points to a propensity for the (HP)2 dimer generation on ice nanoparticles. This shows the feasibility of base pairing for model of biological molecules on free ice nanoparticles. This result is important for hypotheses of the biomolecule synthesis on ice grains in the space. We support our findings by theoretical calculations that show, among others, the HP dimer structures on water clusters. PMID:26785038

  3. A beam hardening correction method based on HL consistency

    NASA Astrophysics Data System (ADS)

    Mou, Xuanqin; Tang, Shaojie; Yu, Hengyong

    2006-08-01

    XCT with polychromatic tube spectrum causes artifact called beam hardening effect. The current correction in CT device is carried by apriori polynomial from water phantom experiment. This paper proposes a new beam hardening correction algorithm that the correction polynomial depends on the relativity of projection data in angles, which obeys Helgasson-Ludwig Consistency (HL Consistency). Firstly, a bi-polynomial is constructed to characterize the beam hardening effect based on the physical model of medical x-ray imaging. In this bi-polynomial, a factor r(γ,β) represents the ratio of the attenuation contributions caused by high density mass (bone, etc.) to low density mass (muscle, vessel, blood, soft tissue, fat, etc.) respectively in the projection angle β and fan angle γ. Secondly, let r(γ,β)=0, the bi-polynomial is degraded as a sole-polynomial. The coefficient of this polynomial can be calculated based on HL Consistency. Then, the primary correction is reached, which is also more efficient in theoretical than the correction method in current CT devices. Thirdly, based on the result of a normal CT reconstruction from the corrected projection data, r(γ,β) can be estimated. Fourthly, the coefficient of bi-polynomial can also be calculated based HL Consistency and the final correction are achieved. Experiments of circular cone beam CT indicate this method an excellent property. Correcting beam hardening effect based on HL Consistency, not only achieving a self-adaptive and more precise correction, but also getting rid of regular inconvenient water phantom experiments, will renovate the correction technique of current CT devices.

  4. Beam-based alignment measurements of the LANSCE linac

    SciTech Connect

    McCrady, R. C.; Rybarcyk, L. J.

    2004-01-01

    We have made measurements of the alignment of the Los Alamos Neutron Science Center (LANSCE) Drift Tube linac (DTL) and Side Coupled linac (SCL) using beam position measurements and analyzing them with linear models. In the DTL, we varied the injection steering and focusing lattice strengths, measured the beam position after each DTL tank, and analyzed the data with a linear model using R-matrices that were either computed by the Trace-3D computer program or extracted from analysis of the data. The analysis model allowed for tank-to-tank misalignments. The measurements were made similarly in the SCL, where the analysis model allowed for misalignments of each quadrupole doublet lens. We present here the analysis techniques and the resulting beam-based alignment measurements.

  5. Beam halo definitions based upon moments of the particle distribution

    NASA Astrophysics Data System (ADS)

    Allen, C. K.; Wangler, T. P.

    2002-12-01

    Two different parameters for the quantitative description of beam halo are discussed. Both are based on moments of the particle distribution and represent a convenient and model-independent method for quantifying the magnitude of beam halo observed in either spatial or phase-space projections. One parameter is a measure of spatial profile of the beam and has been defined by Wangler and Crandall previously. The current authors defined a new parameter using kinematic invariants to quantify halo formation in 2D phase space. Here we expand the development and present detailed numerical results. Although the spatial-profile parameter and the phase-space halo parameter both reduce to the same value when the distribution has the elliptical symmetry, in general these parameters are not equal. Halo in the 1D spatial profiles is relatively easily measured, but is variable as the beam distribution evolves and can hide as it rotates in phase space. The 2D phase-space halo is more difficult to measure, but it varies more smoothly as the halo evolves. It provides a more reliable characterization of the halo as an intrinsic property of the beam.

  6. A configurable electronics system for the ESS-Bilbao beam position monitors

    NASA Astrophysics Data System (ADS)

    Muguira, L.; Belver, D.; Etxebarria, V.; Varnasseri, S.; Arredondo, I.; del Campo, M.; Echevarria, P.; Garmendia, N.; Feuchtwanger, J.; Jugo, J.; Portilla, J.

    2013-09-01

    A versatile and configurable system has been developed in order to monitorize the beam position and to meet all the requirements of the future ESS-Bilbao Linac. At the same time the design has been conceived to be open and configurable so that it could eventually be used in different kinds of accelerators, independent of the charged particle, with minimal change. The design of the Beam Position Monitors (BPMs) system includes a test bench both for button-type pick-ups (PU) and striplines (SL), the electronic units and the control system. The electronic units consist of two main parts. The first part is an Analog Front-End (AFE) unit where the RF signals are filtered, conditioned and converted to base-band. The second part is a Digital Front-End (DFE) unit which is based on an FPGA board where the base-band signals are sampled in order to calculate the beam position, the amplitude and the phase. To manage the system a Multipurpose Controller (MC) developed at ESSB has been used. It includes the FPGA management, the EPICS integration and Archiver Instances. A description of the system and a comparison between the performance of both PU and SL BPM designs measured with this electronics system are fully described and discussed.

  7. Beam shaping for laser-based adaptive optics in astronomy.

    PubMed

    Béchet, Clémentine; Guesalaga, Andrés; Neichel, Benoit; Fesquet, Vincent; González-Núñez, Héctor; Zúñiga, Sebastián; Escarate, Pedro; Guzman, Dani

    2014-06-01

    The availability and performance of laser-based adaptive optics (AO) systems are strongly dependent on the power and quality of the laser beam before being projected to the sky. Frequent and time-consuming alignment procedures are usually required in the laser systems with free-space optics to optimize the beam. Despite these procedures, significant distortions of the laser beam have been observed during the first two years of operation of the Gemini South multi-conjugate adaptive optics system (GeMS). A beam shaping concept with two deformable mirrors is investigated in order to provide automated optimization of the laser quality for astronomical AO. This study aims at demonstrating the correction of quasi-static aberrations of the laser, in both amplitude and phase, testing a prototype of this two-deformable mirror concept on GeMS. The paper presents the results of the preparatory study before the experimental phase. An algorithm to control amplitude and phase correction, based on phase retrieval techniques, is presented with a novel unwrapping method. Its performance is assessed via numerical simulations, using aberrations measured at GeMS as reference. The results predict effective amplitude and phase correction of the laser distortions with about 120 actuators per mirror and a separation of 1.4 m between the mirrors. The spot size is estimated to be reduced by up to 15% thanks to the correction. In terms of AO noise level, this has the same benefit as increasing the photon flux by 40%. PMID:24921496

  8. Cardiac rate detection method based on the beam splitter prism

    NASA Astrophysics Data System (ADS)

    Yang, Lei; Liu, Xiaohua; Liu, Ming; Zhao, Yuejin; Dong, Liquan; Zhao, Ruirui; Jin, Xiaoli; Zhao, Jingsheng

    2013-09-01

    A new cardiac rate measurement method is proposed. Through the beam splitter prism, the common-path optical system of transmitting and receiving signals is achieved. By the focusing effect of the lens, the small amplitude motion artifact is inhibited and the signal-to-noise is improved. The cardiac rate is obtained based on the PhotoPlethysmoGraphy (PPG). We use LED as the light source and use photoelectric diode as the receiving tube. The LED and the photoelectric diode are on the different sides of the beam splitter prism and they form the optical system. The signal processing and display unit is composed by the signal processing circuit, data acquisition device and computer. The light emitted by the modulated LED is collimated by the lens and irradiates the measurement target through the beam splitter prism. The light reflected by the target is focused on the receiving tube through the beam splitter prism and another lens. The signal received by the photoelectric diode is processed by the analog circuit and obtained by the data acquisition device. Through the filtering and Fast Fourier Transform, the cardiac rate is achieved. We get the real time cardiac rate by the moving average method. We experiment with 30 volunteers, containing different genders and different ages. We compare the signals captured by this method to a conventional PPG signal captured concurrently from a finger. The results of the experiments are all relatively agreeable and the biggest deviation value is about 2bmp.

  9. Red beam generation based on aperiodically poled lithium niobate

    NASA Astrophysics Data System (ADS)

    Figen, Ziya Gürkan; Akın, Onur

    2014-04-01

    We propose a novel device with a simple architecture for high-power red beam generation. The device is an optical parametric generator based on an aperiodically poled LiNbO3 grating in which both the optical parametric amplification and sum frequency generation processes are simultaneously phase matched. The pump is a quasi-continuous-wave laser operating at 1064 nm. Aperiodic gratings which enable simultaneous phase matching of the two processes were designed using a method that gives the flexibility to adjust the relative strength of these two processes. A model that takes the diffraction of the beams into account was developed to characterize the red beam generation performance of the device depending on the parameters: the relative strength of these processes, the length of the crystal, the average pump power, and the pump beam waist radius. If one uses the 2-D Fourier transform in the solution of the coupled-mode equations, the computation power required for performing such a characterization on a personal computer is prohibitively large. Owing to the circular symmetry of the system, we employ the Hankel transform to overcome this bottleneck.

  10. Beam splitting target reflector based compensation for angular drift of laser beam in laser autocollimation of measuring small angle deviations

    SciTech Connect

    Zhu Fan; Tan Jiubin; Cui Jiwen

    2013-06-15

    Beam splitting target reflector based compensation for the angular drift of laser beam in laser autocollimation is proposed in this article to improve the measurement accuracy and stability of small angle deviations. A beam splitting target reflector is used to replace the plane mirror in laser autocollimation to generate a reference beam when returning the measurement beam. The reference beam and measurement beam have the same angular drift, but have different sensitivities to the rotation angle of the reflector due to the unique characteristics of the reflector. Thus, the angular drift of laser beam in laser autocollimation can be compensated in real time by using the drift of reference beam. Experimental results indicate that an output stability of 0.085 arc sec in 2 h can be achieved after compensation. And a measurement accuracy of {+-}0.032 arc sec can be obtained over the range of {+-}1190 arc sec with an effective resolution of 0.006 arc sec. It is confirmed that the compensation method for the angular drift of laser beam is necessary for improving the measurement accuracy and stability in laser autocollimation.

  11. A power beaming based infrastructure for space power

    SciTech Connect

    Bamberger, J.A.

    1991-08-01

    At present all space mission power requirements are met by integral, on-board, self-contained power systems. To provide needed flexibility for space exploration and colonization, an additional approach to on-board, self-contained power systems is needed. Power beaming, an alternative approach to providing power, has the potential to provide increased mission flexibility while reducing total mass launched into space. Laser-power beaming technology provides a viable power and communication infrastructure that can be developed sequentially as it is applied to power satellite constellations in Earth orbit and to orbital transport vehicles transferring satellites and cargos to geosynchronous orbit and beyond. Coupled with nuclear electric propulsion systems for cargo transport, the technology can be used to provide global power to the Lunar surface and to Mars' surface and moons. The technology can be developed sequentially as advances in power system and propulsion system technology occur. This paper presents stepwise development of an infrastructure based on power beaming that can support the space development and exploration goals of the Space Exploration Initiative. Power scenarios based on commonality of power systems hardware with cargo transport vehicles are described. Advantages of this infrastructure are described. 12 refs., 4 figs., 1 tab.

  12. Beam-Based Solenoid Compensation for the PEP-II

    SciTech Connect

    Cai, Yunhai

    1999-08-26

    Commissioning the compensation system of the solenoid in the BaBar detector presents a challenging problem due to the complexity of the system, which uses twelve normal quadrupoles and twelve skew quadrupoles in each ring. The setting of these skew quadrupoles needs to be readjusted according to the machine optical parameters since the machines always have some unknown errors. In this paper, we will describe a beam based method to match the coupling and optics in the interaction region to compensate for the optical effects due to the solenoid. The method has been successfully used to find the wrong polarities and the wrong scaling factor of the skew quadrupoles in the early stage of the commissioning. It is being refined to set the skew quadrupoles in the machines in order to reduce the beam size at the interaction point and improve the luminosity of PEP-II.

  13. Filter model based dwell time algorithm for ion beam figuring

    NASA Astrophysics Data System (ADS)

    Li, Yun; Xing, Tingwen; Jia, Xin; Wei, Haoming

    2010-10-01

    The process of Ion Beam Figuring (IBF) can be described by a two-dimensional convolution equation which including dwell time. Solving the dwell time is a key problem in IBF. Theoretically, the dwell time can be solved from a two-dimensional deconvolution. However, it is often ill-posed]; the suitable solution of that is hard to get. In this article, a dwell time algorithm is proposed, depending on the characters of IBF. Usually, the Beam Removal Function (BRF) in IBF is Gaussian, which can be regarded as a headstand Gaussian filter. In its stop-band, the filter has various filtering abilities for various frequencies. The dwell time algorithm proposed in this article is just based on this concept. The Curved Surface Smooth Extension (CSSE) method and Fast Fourier Transform (FFT) algorithm are also used. The simulation results show that this algorithm is high precision, effective, and suitable for actual application.

  14. Performance of exponential coupler in the SPS with LHC type beam for transverse broadband instability analysis

    SciTech Connect

    de Maria,R.; Fox, J. D.; Hofle, W.; Kotzian, G.; Rumolo, G.; Salvant, B.; Wehrle, U.

    2009-05-25

    We present the performance and limitations of the SPS exponential coupler [1] for transverse instability measurements with LHC type beam. Data were acquired in 2008 in the SPS in the time domain with a bandwidth of up to 2.5 GHz. The data were filtered to extract the time evolution of transverse oscillations within the less than 5 ns long LHC type bunches. We describe the data filtering techniques and show the limitations of the pick-up due to propagating modes.

  15. Eringen's small length scale coefficient for buckling of nonlocal Timoshenko beam based on microstructured beam model

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; Challamel, N.; Wang, C. M.

    2013-09-01

    This paper presents the determination of Eringen's small length scale coefficient e0 for buckling of nonlocal Timoshenko beam from a microstructured beam model. The microstructured beam model is composed of discrete rigid elements (of equal length), which are connected by rotational and shear springs that model the bending and shearing behaviors in a beam. The exact solution of e0 is given for nonlocal Timoshenko beam with small length scale term appearing in the normal stress-strain relation only. It is shown that e0 approaches 1/√12 ≈0.289 which coincides with the one calibrated for nonlocal Euler beams.

  16. Trap-Based Beam Formation Mechanisms and the Development of an Ultra-High-Energy-Resolution Cryogenic Positron Beam

    NASA Astrophysics Data System (ADS)

    Natisin, Michael Ryan

    The focus of this dissertation is the development of a positron beam with significantly improved energy resolution over any beam resolution previously available. While positron interactions with matter are important in a variety of contexts, the range of experimental data available regarding fundamental positron-matter interactions is severely limited as compared to analogous electron-matter processes. This difference is due largely to the difficulties encountered in creating positron beams with narrow energy spreads. Described here is a detailed investigation into the physical processes operative during positron cooling and beam formation in state-of-the-art, trap-based beam systems. These beams rely on buffer gas traps (BGTs), in which positrons are trapped and cooled to the ambient temperature (300 K) through interactions with a molecular gas, and subsequently ejected as a high resolution pulsed beam. Experimental measurements, analytic models, and simulation results are used to understand the creation and characterization of these beams, with a focus on the mechanisms responsible for setting beam energy resolution. The information gained from these experimental and theoretical studies was then used to design, construct, and operate a next-generation high-energy-resolution beam system. In this new system, the pulsed beam from the BGT is magnetically guided into a new apparatus which re-traps the positrons, cools them to 50 K, and re-emits them as a pulsed beam with superior beam characteristics. Using these techniques, positron beams with total energy spreads as low as 6.9 meV FWHM are produced. This represents a factor of ˜ 5 improvement over the previous state-of-the-art, making it the largest increase in positron beam energy resolution since the development of advanced moderator techniques in the early 1980's. These beams also have temporal spreads of 0.9 mus FWHM and radial spreads of 1 mm FWHM. This represents improvements by factors of ˜2 and 10

  17. Optical encoder based on a nondiffractive beam III

    SciTech Connect

    Lutenberg, Ariel; Perez-Quintian, Fernando

    2009-09-20

    In two preceding works (Appl. Opt.47, 2201-2206, 2008APOPAI0003-693510.1364/AO.47.002201; Appl. Opt.48, 414-424, 2009APOPAI0003-693510.1364/AO.48.000414) we introduced the design of an optical encoder based on a nondiffractive beam and studied the dependence of its performance on its parameters (e.g., grating pitch, photodetector size). In those works we proposed different optimization criteria and concluded that the proposed design provides an output sinusoidal signal with high contrast and very low harmonic distortion, while having remarkable tolerance to variations in its parameters and to mechanical perturbations. In this work we (1) study how to improve the system performance by means of selecting appropriate photodetector geometry, (2) study the system performance for different nondiffractive beam geometries, and (3) quantify the output signal tolerance to vertical and lateral misalignment between the centers of the nondiffractive beam and the photodetector. As a consequence, we obtain new sets of optimal parameters that significantly improve the system performance and enhance its tolerance to mechanical perturbations and fabrication errors.

  18. Beam characteristics of fiber-based supercontinuum light sources with mirror- and lens-based beam collimators.

    PubMed

    Arnold, Ian J; Moosmüller, Hans; Sharma, Noopur; Mazzoleni, Claudio

    2014-06-01

    Commercially available supercontinuum light sources that cover most of the solar spectrum are well suited for instrumentation, where a well-collimated beam with wide spectral coverage is needed. Typically, the optical power is emitted from a single-mode photonic-crystal fiber and the output can either be collimated using a proprietary, permanently integrated, lens-based collimator or with a customer-provided, off-axis parabolic mirror. Here, we evaluate both approaches and conclude that, superior beam quality and collimation over the whole spectral range can be obtained with an off-axis parabolic mirror, however at the price of a more complex and bulky system requiring additional user alignment. PMID:24921577

  19. A method for calculating strain energy release rate based on beam theory

    NASA Technical Reports Server (NTRS)

    Sun, C. T.; Pandey, R. K.

    1993-01-01

    The Timoshenko beam theory was used to model cracked beams and to calculate the total strain energy release rate. The root rotation of the beam segments at the crack tip were estimated based on an approximate 2D elasticity solution. By including the strain energy released due to the root rotations of the beams during crack extension, the strain energy release rate obtained using beam theory agrees very well with the 2D finite element solution. Numerical examples were given for various beam geometries and loading conditions. Comparisons with existing beam models were also given.

  20. Digitally based pattern generator for an electron-beam welder

    SciTech Connect

    Whitten, L.G. III

    1981-02-19

    A digitally based deflection generator for an electron-beam welder is presented. Up to seven patterns of any shape are stored in programmable read-only memory (PROM). The pattern resolution is 39% at frequencies from 10 Hz to 1 kHz and can be x-t, y-t, or x-y formed. Frequency and pattern selections may be chosen by the welder computer or manually selected on the front panel. The ability to repeatedly synchronize two waveforms of any shape and frequency enables an unlimited variety of welds.

  1. The generation of arbitrary vector beams using a division of a wavefront-based setup

    NASA Astrophysics Data System (ADS)

    Kalita, Ranjan; Gaffar, Md; Boruah, Bosanta R.

    2016-07-01

    In this paper, we introduce an arbitrary vector-beam-forming scheme using a simple arrangement involving only one liquid crystal spatial light modulator. An arbitrary vector beam can be obtained by overlapping two orthogonally polarized beams. In most of the existing vector-beam-forming schemes the two orthogonally polarized beams are essentially copies of a single incident wavefront. However, in the proposed scheme the two orthogonally polarized beams correspond to two separated parts of a single incident wavefront. Taking a cue from the two-beam interference phenomenon, the present scheme can be referred to as a division of a wavefront-based scheme. The proposed setup offers certain important advantages and is more suitable for the generation of higher average-power vector beams. We demonstrate the working of the vector-beam-forming scheme by generating various vector beams such as radially polarized, azimuthally polarized, and Bessel–Gauss beams and also a boat-shaped beam in the focal volume of a low-numerical-aperture focusing lens. The boat-shaped beam comprises a dark center surrounded by intense light from all but one direction. The beam is realized at the focus of an azimuthally polarized beam in the presence of a moderate amount of coma in the beam. The experimental results obtained using the proposed setup are verified by comparing them with the theoretical results.

  2. Raton basin coalbed methane production picking up in Colorado

    SciTech Connect

    Hemborg, H.T.

    1996-11-11

    Coalbed methane production in the Raton basin of south-central Colorado and northeast New Mexico has advanced past pilot testing and is entering into a development stage that should stretch out over several years. At last count 85 wells were producing nearly 17.5 MMcfd of coalbed methane from the basin`s Raton and Vermejo formation coals (Early Paleocene to Latest Maastrichtian). This development work is currently restricted to roughly a 25 mile by 15 mile wide ``fairway`` centered about 20 miles west of Trinidad, Colo., in the headwater area of the Purgatoire River. The paper discusses the companies involved in the basin development, geology of the coal seam, and water disposal from coal seam dewatering.

  3. Picking up Galen: James Joyce in Cecilia Street.

    PubMed

    Lyons, J B

    1997-07-01

    James Joyce (1882-1941) registered as a student of the Catholic University Medical School, Cecilia Street, in 1902. His attendance in November was brief; by early December, Joyce was in Paris. A recently-acquired Guide for Medical Students, a booklet compiled by Ambrose Birmingham, dean of the Cecilia Street school, sheds light on this hitherto obscure episode. PMID:11619448

  4. Picking up Clues from the Discard Pile (Stereo)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    As NASA's Phoenix Mars Lander excavates trenches, it also builds piles with most of the material scooped from the holes. The piles, like this one called 'Caterpillar,' provide researchers some information about the soil.

    On Aug. 24, 2008, during the late afternoon of the 88th Martian day after landing, Phoenix's Surface Stereo Imager took separate exposures through its left eye and right eye that have been combined into this stereo view. The image appears three dimensional when seen through red-blue glasses.

    This conical pile of soil is about 10 centimeters (4 inches) tall. The sources of material that the robotic arm has dropped onto the Caterpillar pile have included the 'Dodo' and ''Upper Cupboard' trenches and, more recently, the deeper 'Stone Soup' trench.

    Observations of the pile provide information, such as the slope of the cone and the textures of the soil, that helps scientists understand properties of material excavated from the trenches.

    For the Stone Soup trench in particular, which is about 18 centimeters (7 inches) deep, the bottom of the trench is in shadow and more difficult to observe than other trenches that Phoenix has dug. The Phoenix team obtained spectral clues about the composition of material from the bottom of Stone Soup by photographing Caterpillar through 15 different filters of the Surface Stereo Imager when the pile was covered in freshly excavated material from the trench.

    The spectral observation did not produce any sign of water-ice, just typical soil for the site. However, the bigger clumps do show a platy texture that could be consistent with elevated concentration of salts in the soil from deep in Stone Soup. The team chose that location as the source for a soil sample to be analyzed in the lander's wet chemistry laboratory, which can identify soluble salts in the soil.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  5. Essays of a peripheral mind: Picking up rocks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2008 the Heinz Center released its report “The State of the Nation’s Ecosystems, 2008.” The current report provides sets of assessments on the status of the nation’s rangelands an area of approximately 1 billion acres. Unfortunately, on numerous occasions the report contains the phase “Data Gap...

  6. Physics papers get poor pick-up on social media

    NASA Astrophysics Data System (ADS)

    Lavender, Gemma

    2014-02-01

    A list of the 100 most popular scientific papers that were discussed on social media in 2013 - those that had the most "likes" on Facebook, Tweets or coverage in blogs - is dominated by papers in biology and the social sciences, with physics and mathematics papers only taking up a couple of places on the list.

  7. Seasonal Variation of Martian Pick-up Ions

    NASA Astrophysics Data System (ADS)

    Yamauchi, M.; Hara, T.; Lundin, R.; Dubinin, E.; Fedorov, A.; Sauvaud, J.-A.; Frahm, R.; Ramstad, R.; Futaana, Y.; Holmstrom, M.; Barabash, S.

    2015-10-01

    Statistics of Mars Express (MEX) ion mass analyser(IMA) data shows that ion production from exospheric hydrogen depends more on the Sun-Mars distance than the solar cycle phase or winter-summer hemispheric difference. This indicates that the EUV is not the only driver of the production of cold, exospheric-origin ions, and that the extension of the exosphere is strongly influenced by total irradiance that carries the majority of the solar energy to the Martian atmosphere.

  8. Hunt for improved carbon capture picks up speed

    SciTech Connect

    2010-01-01

    A high-throughput metal-organic framework synthesis instrument in action. Berkeley Lab chemist Jeffrey Long's lab will soon host a round-the-clock, robotically choreographed hunt for carbon-hungry materials. The Berkeley Lab chemist leads a diverse team of scientists whose goal is to quickly discover materials that can efficiently strip carbon dioxide from a power plant's exhaust, before it leaves the smokestack and contributes to climate change. They're betting on a recently discovered class of materials called metal-organic frameworks, which boast a record-shattering internal surface area. A sugar cube-sized piece, if unfolded and flattened, would more than blanket a football field. The crystalline material can also be tweaked to absorb specific molecules. More: http://newscenter.lbl.gov/feature-stories/2010/05/26/carbon-capture-search/

  9. Raton basin coalbed methane production picking up in Colorado

    USGS Publications Warehouse

    Hemborg, H. Thomas

    1996-01-01

    Coalbed methane production in the Raton basin of south-central Colorado and northeast New Mexico has gone over pilot testing and entered the development stage which is expected to last several years. The development work is restricted to roughly a 25 mile by 15 mile wide `fairway' centered about 20 miles west of Trinidad, Colorado. At last count, 85 wells were producing nearly 17.5 MMcfd of coalbed methane from the basin's Raton and Vermejo formation coals.

  10. High-performance spinning device for DVD-based micromechanical signal transduction

    NASA Astrophysics Data System (ADS)

    Hwu, En-Te; Chen, Ching-Hsiu; Bosco, Filippo G.; Wang, Wei-Min; Ko, Hsien-Chen; Hwang, Ing-Shouh; Boisen, Anja; Huang, Kuang-Yuh

    2013-04-01

    Here we report a high-throughput spinning device for nanometric scale measurements of microstructures with instrumentation details and experimental results. The readout technology implemented in the designed disc-like device is based on a DVD data storage optical pick-up unit (OPU). With a spinning mechanism, this device can simultaneously measure surface topography, mechanical deflections and resonance frequencies of several microfabricated beams at a high speed. In biochemical sensing applications, the OPU can measure bending changes of functionalized microcantilevers, providing a statistically robust and label-free bio-detection analysis of multiple compounds. The signal-to-noise ratio (S/N) is demonstrated from statistical measurements as 1.2 with arginine detection at 750 nM concentration. Practically, the OPU can measure up to 480 individual cantilever sensors per second with nanometer resolution. The opto-mechanical optimization of the device design and settings for biochemical detection are described.

  11. Beam-based optical tuning of the final focus test beam

    SciTech Connect

    Tenenbaum, P.; Burke, D.; Hartman, S.; Helm, R.; Irwin, J.; Iverson, R.; Raimondi, P.; Spence, W.; Bharadwaj, V.; Halling, M.

    1995-05-01

    In order to reduce the SLAC 46.6 GeV beam to submicron sizes, the Final Focus Test Beam (FFTB) must meet tight tolerances on many aberrations. These aberrations include: mismatch and coupling of the incoming beam; dispersion; chromaticity; lattice errors in the chromatic correction sections; lattice coupling; and residual sextupole content in the quadrupoles. In order to address these aberrations, the authors have developed a procedure which combines trajectory analysis, use of intermediate wire scanners, and a pair of novel beam size monitors at the IP. This procedure allows the FFTB IP spot to be reduced to sizes under 100 nanometers.

  12. Converter of laser beams with circular polarization to cylindrical vector beams based on anisotropic crystals

    NASA Astrophysics Data System (ADS)

    Paranin, Vyacheslav D.; Karpeev, Sergey V.; Kazanskiy, Nikolay L.; Krasnov, Andrey P.

    2016-03-01

    The optical system for converting laser beams with circular polarization to cylindrical vector beams on the basis of anisotropic crystals has been developed. The experimental research of beam formation quality has been carried out on the both polarization and structural characteristics. The research showed differences in the formation of the azimuthal and radial polarizations for Gaussian modes and Bessel beams. The boundaries of changes of the optical system parameters to form different types of polarizations with different amplitude and phase distributions have been identified.

  13. Instantaneous electron beam emittance measurement system based on the optical transition radiation principle

    NASA Astrophysics Data System (ADS)

    Jiang, Xiao-Guo; Wang, Yuan; Zhang, Kai-Zhi; Yang, Guo-Jun; Shi, Jin-Shui; Deng, Jian-Jun; Li, Jin

    2014-01-01

    One kind of instantaneous electron beam emittance measurement system based on the optical transition radiation principle and double imaging optical method has been set up. It is mainly adopted in the test for the intense electron-beam produced by a linear induction accelerator. The system features two characteristics. The first one concerns the system synchronization signal triggered by the following edge of the main output waveform from a Blumlein switch. The synchronous precision of about 1 ns between the electron beam and the image capture time can be reached in this way so that the electron beam emittance at the desired time point can be obtained. The other advantage of the system is the ability to obtain the beam spot and beam divergence in one measurement so that the calculated result is the true beam emittance at that time, which can explain the electron beam condition. It provides to be a powerful beam diagnostic method for a 2.5 kA, 18.5 MeV, 90 ns (FWHM) electron beam pulse produced by Dragon I. The ability of the instantaneous measurement is about 3 ns and it can measure the beam emittance at any time point during one beam pulse. A series of beam emittances have been obtained for Dragon I. The typical beam spot is 9.0 mm (FWHM) in diameter and the corresponding beam divergence is about 10.5 mrad.

  14. Ground-Based and Space-Based Laser Beam Power Applications

    NASA Technical Reports Server (NTRS)

    Bozek, John M.

    1995-01-01

    A space power system based on laser beam power is sized to reduce mass, increase operational capabilities, and reduce complexity. The advantages of laser systems over solar-based systems are compared as a function of application. Power produced from the conversion of a laser beam that has been generated on the Earth's surface and beamed into cislunar space resulted in decreased round-trip time for Earth satellite electric propulsion tugs and a substantial landed mass savings for a lunar surface mission. The mass of a space-based laser system (generator in space and receiver near user) that beams down to an extraterrestrial airplane, orbiting spacecraft, surface outpost, or rover is calculated and compared to a solar system. In general, the advantage of low mass for these space-based laser systems is limited to high solar eclipse time missions at distances inside Jupiter. The power system mass is less in a continuously moving Mars rover or surface outpost using space-based laser technology than in a comparable solar-based power system, but only during dust storm conditions. Even at large distances for the Sun, the user-site portion of a space-based laser power system (e.g., the laser receiver component) is substantially less massive than a solar-based system with requisite on-board electrochemical energy storage.

  15. Beam based alignment of sector-1 of the SLC linac

    SciTech Connect

    Emma, P.

    1992-03-01

    A technique is described which uses the beam to simultaneously measure quadrupole magnet and beam position monitor (BPM) transverse misalignments. The technique is applied to sector-1 of the SLC linac where simultaneous acceleration of electron and positron beams with minimal steering elements and BPMs makes quadrupole alignment critical for high transmission of the large transverse emittance positron beam. Simulation results as well as measurements are presented.

  16. Beam based alignment and its relevance in Indus-2.

    PubMed

    Jena, Saroj Kumar; Husain, Riyasat; Gandhi, M L; Agrawal, R K; Yadav, S; Ghodke, A D

    2015-09-01

    Initially in the Indus-2 storage ring, the closed orbit distortion (COD) could be best corrected to 1.3 mm rms in the horizontal and 0.43 mm rms in the vertical plane. The strength of the corrector magnets required high values for COD correction. This revealed that offsets in COD readout by the beam position monitors (BPMs) played a role in not achieving a rms COD lower than the above value. Thus, the offset between the electrical center of BPMs and the magnetic center of the nearest quadrupole magnet could be estimated using the beam based alignment (BBA) method. It prefers that the quadrupole magnet is able to be controlled individually and active shunt power supply (ASPS) system was designed for this purpose that works efficiently. This paper describes the methodology of BBA, topology of ASPS and its performance, and COD minimization using the measured BPM offsets. After BBA, the COD could be reduced to 0.45 mm rms and 0.2 mm rms in horizontal and vertical planes, respectively. PMID:26429436

  17. Beam based alignment and its relevance in Indus-2

    SciTech Connect

    Jena, Saroj Kumar; Husain, Riyasat; Gandhi, M. L.; Agrawal, R. K.; Yadav, S.; Ghodke, A. D.

    2015-09-15

    Initially in the Indus-2 storage ring, the closed orbit distortion (COD) could be best corrected to 1.3 mm rms in the horizontal and 0.43 mm rms in the vertical plane. The strength of the corrector magnets required high values for COD correction. This revealed that offsets in COD readout by the beam position monitors (BPMs) played a role in not achieving a rms COD lower than the above value. Thus, the offset between the electrical center of BPMs and the magnetic center of the nearest quadrupole magnet could be estimated using the beam based alignment (BBA) method. It prefers that the quadrupole magnet is able to be controlled individually and active shunt power supply (ASPS) system was designed for this purpose that works efficiently. This paper describes the methodology of BBA, topology of ASPS and its performance, and COD minimization using the measured BPM offsets. After BBA, the COD could be reduced to 0.45 mm rms and 0.2 mm rms in horizontal and vertical planes, respectively.

  18. Beam based alignment and its relevance in Indus-2

    NASA Astrophysics Data System (ADS)

    Jena, Saroj Kumar; Husain, Riyasat; Gandhi, M. L.; Agrawal, R. K.; Yadav, S.; Ghodke, A. D.

    2015-09-01

    Initially in the Indus-2 storage ring, the closed orbit distortion (COD) could be best corrected to 1.3 mm rms in the horizontal and 0.43 mm rms in the vertical plane. The strength of the corrector magnets required high values for COD correction. This revealed that offsets in COD readout by the beam position monitors (BPMs) played a role in not achieving a rms COD lower than the above value. Thus, the offset between the electrical center of BPMs and the magnetic center of the nearest quadrupole magnet could be estimated using the beam based alignment (BBA) method. It prefers that the quadrupole magnet is able to be controlled individually and active shunt power supply (ASPS) system was designed for this purpose that works efficiently. This paper describes the methodology of BBA, topology of ASPS and its performance, and COD minimization using the measured BPM offsets. After BBA, the COD could be reduced to 0.45 mm rms and 0.2 mm rms in horizontal and vertical planes, respectively.

  19. Quadrupole beam-based alignment in the RHIC interaction regions

    SciTech Connect

    Ziegler, J.; Satogata, T.

    2011-03-28

    Continued beam-based alignment (BBA) efforts have provided significant benefit to both heavy ion and polarized proton operations at RHIC. Recent studies demonstrated previously unknown systematic beam position monitor (BPM) offset errors and produced accurate measurements of individual BPM offsets in the experiment interaction regions. Here we describe the algorithm used to collect and analyze data during the 2010 and early 2011 RHIC runs and the results of these measurements. BBA data has been collected over the past two runs for all three of the active experimental IRs at RHIC, updating results from the 2005 run which were taken with incorrectly installed offsets. The technique was successfully applied to expose a systematic misuse of the BPM survey offsets in the control system. This is likely to benefit polarized proton operations as polarization transmission through acceleration ramps depends on RMS orbit control in the arcs, but a quantitative understanding of its impact is still under active investigation. Data taking is ongoing as are refinements to the BBA technique aimed at reducing systematic errors and properly accounting for dispersive effects. Further development may focus on non-triplet BPMs such as those located near snakes, or arc quadrupoles that do not have individually shunted power supplies (a prerequisite for the current method) and as such, will require a modified procedure.

  20. Beam-Based Alignment of Magnetic Field in the Fermilab Electron Cooler Cooling Section

    SciTech Connect

    Seletskiy, S. M.; Tupikov, V.

    2006-03-20

    The Fermilab Electron Cooling Project requires low effective anglular spread of electrons in the cooling section. One of the main components of the effective electron angles is an angle of electron beam centroid with respect to antiproton beam. This angle is caused by the poor quality of magnetic field in the 20 m long cooling section solenoid and by the mismatch of the beam centroid to the entrance of the cooling section. This paper focuses on the beam-based procedure of the alignment of the cooling section field and beam centroid matching. The discussed procedure allows to suppress the beam centroid angles below the critical value of 0.1 mrad.

  1. Neutralization efficiency estimation in a neutral beam source based on inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Vozniy, O. V.; Yeom, G. Y.

    2009-01-01

    This study examined the optimal conditions of neutral beam generation to maintain a high degree of neutralization and focusing during beam energy variation for a neutral beam source based on inductively coupled plasma with a three-grid ion beam acceleration system. The neutral beam energy distribution was estimated by measuring the energy profiles of ions that "survived" the neutralization after reflection. The energy measurements of the primary and reflected ions showed narrow distribution functions, each with only one peak. At higher beam energies, both the ratio of the ion energy loss to the primary energy and the degree of energy divergence decreased, confirming the precise alignment of the neutral beam. The neutralization efficiency of the neutral beam source with a three-grid acceleration system was found to be affected mainly by the beam angle divergence rather than by the particle translation energy.

  2. Neutralization efficiency estimation in a neutral beam source based on inductively coupled plasma

    SciTech Connect

    Vozniy, O. V.; Yeom, G. Y.

    2009-01-01

    This study examined the optimal conditions of neutral beam generation to maintain a high degree of neutralization and focusing during beam energy variation for a neutral beam source based on inductively coupled plasma with a three-grid ion beam acceleration system. The neutral beam energy distribution was estimated by measuring the energy profiles of ions that 'survived' the neutralization after reflection. The energy measurements of the primary and reflected ions showed narrow distribution functions, each with only one peak. At higher beam energies, both the ratio of the ion energy loss to the primary energy and the degree of energy divergence decreased, confirming the precise alignment of the neutral beam. The neutralization efficiency of the neutral beam source with a three-grid acceleration system was found to be affected mainly by the beam angle divergence rather than by the particle translation energy.

  3. The backward phase flow and FBI-transform-based Eulerian Gaussian beams for the Schroedinger equation

    SciTech Connect

    Leung Shingyu; Qian Jianliang

    2010-11-20

    We propose the backward phase flow method to implement the Fourier-Bros-Iagolnitzer (FBI)-transform-based Eulerian Gaussian beam method for solving the Schroedinger equation in the semi-classical regime. The idea of Eulerian Gaussian beams has been first proposed in . In this paper we aim at two crucial computational issues of the Eulerian Gaussian beam method: how to carry out long-time beam propagation and how to compute beam ingredients rapidly in phase space. By virtue of the FBI transform, we address the first issue by introducing the reinitialization strategy into the Eulerian Gaussian beam framework. Essentially we reinitialize beam propagation by applying the FBI transform to wavefields at intermediate time steps when the beams become too wide. To address the second issue, inspired by the original phase flow method, we propose the backward phase flow method which allows us to compute beam ingredients rapidly. Numerical examples demonstrate the efficiency and accuracy of the proposed algorithms.

  4. Hough Transform Based Corner Detection for Laser Beam Positioning

    SciTech Connect

    Awwal, A S

    2005-07-26

    In laser beam alignment in addition to detecting position, one must also determine the rotation of the beam. This is essential when a commissioning new laser beam for National Ignition Facility located at the Lawrence Livermore National Laboratory. When the beam is square, the positions of the corners with respect to one another provides an estimate of the rotation of the beam. This work demonstrates corner detection in the presence or absence of a second order non-uniform illumination caused by a spatial mask. The Hough transform coupled with illumination dependent pre-processing is used to determine the corner points. We show examples from simulated and real NIF images.

  5. Formation of buffer-gas-trap based positron beams

    SciTech Connect

    Natisin, M. R. Danielson, J. R. Surko, C. M.

    2015-03-15

    Presented here are experimental measurements, analytic expressions, and simulation results for pulsed, magnetically guided positron beams formed using a Penning-Malmberg style buffer gas trap. In the relevant limit, particle motion can be separated into motion along the magnetic field and gyro-motion in the plane perpendicular to the field. Analytic expressions are developed which describe the evolution of the beam energy distributions, both parallel and perpendicular to the magnetic field, as the beam propagates through regions of varying magnetic field. Simulations of the beam formation process are presented, with the parameters chosen to accurately replicate experimental conditions. The initial conditions and ejection parameters are varied systematically in both experiment and simulation, allowing the relevant processes involved in beam formation to be explored. These studies provide new insights into the underlying physics, including significant adiabatic cooling, due to the time-dependent beam-formation potential. Methods to improve the beam energy and temporal resolution are discussed.

  6. Planar metamaterial-based beam-scanning broadband microwave antenna

    NASA Astrophysics Data System (ADS)

    Dhouibi, Abdallah; Burokur, Shah Nawaz; de Lustrac, André

    2014-05-01

    The broadband directive emission from the use of waveguided metamaterials is numerically and experimentally reported. The metamaterials, which are composed of non-resonant circular complementary closed ring structures printed on a dielectric substrate, are designed to obey the refractive index of a Luneburg lens. An arc array of planar radiating slot antennas placed at the periphery of the lens is used as wave launchers. A prototype of the lens associated with the feed structures has been fabricated using standard lithography techniques. To experimentally demonstrate the broadband focusing properties and directive emissions, far-field radiation patterns have been measured. Furthermore, this metamaterial-based lens can be used to achieve beam-scanning with a coverage of up to 120 °. Far-field measurements agree qualitatively with calculated near-field distributions.

  7. Optical encoder based on a nondiffractive beam II

    SciTech Connect

    Lutenberg, Ariel; Perez-Quintian, Fernando

    2009-01-10

    In a previous work, we introduced the design of an optical encoder based on a nondiffractive beam and demonstrated that it generates a suitable output sinusoidal signal [Appl. Opt.47, 2201-2206 (2008)APOPAI0003-693510.1364/AO.47.002201]. In this work, we experimentally, analytically, and numerically study the dependence of the system performance on its parameters (grating pitch, photodetector size, etc.) and propose three different optimization criteria for which the tolerance to variations in the system parameters is also analyzed. We conclude that the proposed design generates a suitable output signal, with high contrast and very low harmonic distortion, while having a remarkable tolerance to variations in its parameters and to mechanical perturbations.

  8. Embedded design based virtual instrument program for positron beam automation

    NASA Astrophysics Data System (ADS)

    Jayapandian, J.; Gururaj, K.; Abhaya, S.; Parimala, J.; Amarendra, G.

    2008-10-01

    Automation of positron beam experiment with a single chip embedded design using a programmable system on chip (PSoC) which provides easy interfacing of the high-voltage DC power supply is reported. Virtual Instrument (VI) control program written in Visual Basic 6.0 ensures the following functions (i) adjusting of sample high voltage by interacting with the programmed PSoC hardware, (ii) control of personal computer (PC) based multi channel analyzer (MCA) card for energy spectroscopy, (iii) analysis of the obtained spectrum to extract the relevant line shape parameters, (iv) plotting of relevant parameters and (v) saving the file in the appropriate format. The present study highlights the hardware features of the PSoC hardware module as well as the control of MCA and other units through programming in Visual Basic.

  9. Planar metamaterial-based beam-scanning broadband microwave antenna

    SciTech Connect

    Dhouibi, Abdallah; Burokur, Shah Nawaz Lustrac, André de

    2014-05-21

    The broadband directive emission from the use of waveguided metamaterials is numerically and experimentally reported. The metamaterials, which are composed of non-resonant circular complementary closed ring structures printed on a dielectric substrate, are designed to obey the refractive index of a Luneburg lens. An arc array of planar radiating slot antennas placed at the periphery of the lens is used as wave launchers. A prototype of the lens associated with the feed structures has been fabricated using standard lithography techniques. To experimentally demonstrate the broadband focusing properties and directive emissions, far-field radiation patterns have been measured. Furthermore, this metamaterial-based lens can be used to achieve beam-scanning with a coverage of up to 120 °. Far-field measurements agree qualitatively with calculated near-field distributions.

  10. Packaging consideration of two-dimensional polymer-based photonic crystals for laser beam steering

    NASA Astrophysics Data System (ADS)

    Dou, Xinyuan; Chen, Xiaonan; Chen, Maggie Yihong; Wang, Alan Xiaolong; Jiang, Wei; Chen, Ray T.

    2009-02-01

    In this paper, we report the theoretical study of polymer-based photonic crystals for laser beam steering which is based on the superprism effect as well as the experiment fabrication of the two dimensional photonic crystals for the laser beam steering. Superprism effect, the principle for beam steering, was separately studied in details through EFC (Equifrequency Contour) analysis. Polymer based photonic crystals were fabricated through double exposure holographic interference method using SU8-2007. The experiment results were also reported.

  11. Adaptive beam shaper based on a single liquid crystal cell

    NASA Astrophysics Data System (ADS)

    Zenou, Michael; Reznikov, Mitya; Manevich, Michael; Varshal, Joseph; Reznikov, Yuriy; Kotler, Zvi

    2013-03-01

    We describe a method allowing rapid transformation of a Gaussian input laser beam into a variety of beam profiles such as top-hat and ring-shaped. A liquid crystal cell with a simple binary phase structure was designed and prepared using microlithographic processes. The new design provides an electrically tunable, variable mode, beam shaping device with millisecond response time (ton˜5 ms and toff˜35 ms).

  12. Accelerator development for a radioactive beam facility based on ATLAS.

    SciTech Connect

    Shepard, K. W.

    1998-01-08

    The existing superconducting linac ATLAS is in many respects an ideal secondary beam accelerator for an ISOL (Isotope separator on-line) type radioactive beam facility. Such a facility would require the addition of two major accelerator elements: a low charge state injector for the existing heavy ion linac, and a primary beam accelerator providing 220 MV of acceleration for protons and light ions. Development work for both of these elements, including the option of superconducting cavities for the primary beam accelerator is discussed.

  13. High-speed femtosecond laser beam shaping based on binary holography using a digital micromirror device.

    PubMed

    Cheng, Jiyi; Gu, Chenglin; Zhang, Dapeng; Chen, Shih-Chi

    2015-11-01

    In this Letter, we present a digital micromirror device (DMD)-based ultrafast beam shaper, i.e., DUBS. To our knowledge, the DUBS is the first binary laser beam shaper that can generate high-resolution (1140×912 pixels) arbitrary beam modes for femtosecond lasers at a rate of 4.2 kHz; the resolution and pattern rate are limited by the DMD. In the DUBS, the spectrum of the input pulsed laser is first angularly dispersed by a transmission grating and subsequently imaged to a DMD with beam modulation patterns; the transmission grating and a high-reflectivity mirror together compensate the angular dispersion introduced by the DMD. The mode of the output beam is monitored by a CCD camera. In the experiments, the DUBS is programmed to generate four different beam modes, including an Airy beam, Bessel beam, Laguerre-Gaussian (LG) beam, and a custom-designed "peace-dove" beam via the principle of binary holography. To verify the high shaping rate, the Airy beam and LG beam are generated alternately at 4.2 kHz, i.e., the maximum pattern rate of our DMD. The overall efficiency of the DUBS is measured to be 4.7%. With the high-speed and high-resolution beam-shaping capability, the DUBS may find important applications in nonlinear microscopy, optical manipulation, and microscale/nanoscale laser machining, etc. PMID:26512472

  14. GPU-based cone-beam reconstruction using wavelet denoising

    NASA Astrophysics Data System (ADS)

    Jin, Kyungchan; Park, Jungbyung; Park, Jongchul

    2012-03-01

    The scattering noise artifact resulted in low-dose projection in repetitive cone-beam CT (CBCT) scans decreases the image quality and lessens the accuracy of the diagnosis. To improve the image quality of low-dose CT imaging, the statistical filtering is more effective in noise reduction. However, image filtering and enhancement during the entire reconstruction process exactly may be challenging due to high performance computing. The general reconstruction algorithm for CBCT data is the filtered back-projection, which for a volume of 512×512×512 takes up to a few minutes on a standard system. To speed up reconstruction, massively parallel architecture of current graphical processing unit (GPU) is a platform suitable for acceleration of mathematical calculation. In this paper, we focus on accelerating wavelet denoising and Feldkamp-Davis-Kress (FDK) back-projection using parallel processing on GPU, utilize compute unified device architecture (CUDA) platform and implement CBCT reconstruction based on CUDA technique. Finally, we evaluate our implementation on clinical tooth data sets. Resulting implementation of wavelet denoising is able to process a 1024×1024 image within 2 ms, except data loading process, and our GPU-based CBCT implementation reconstructs a 512×512×512 volume from 400 projection data in less than 1 minute.

  15. Avalanche photodiode based detector for beam emission spectroscopy

    SciTech Connect

    Dunai, D.; Zoletnik, S.; Sarkoezi, J.; Field, A. R.

    2010-10-15

    An avalanche photodiode based (APD) detector for the visible wavelength range was developed for low light level, high frequency beam emission spectroscopy (BES) experiments in fusion plasmas. This solid state detector has higher quantum efficiency than photomultiplier tubes, and unlike normal photodiodes, it has internal gain. This paper describes the developed detector as well as the noise model of the electronic circuit. By understanding the noise sources and the amplification process, the optimal amplifier and APD reverse voltage setting can be determined, where the signal-to-noise ratio is the highest for a given photon flux. The calculations are compared to the absolute calibration results of the implemented circuit. It was found that for a certain photon flux range, relevant for BES measurements ({approx_equal}10{sup 8}-10{sup 10} photons/s), the new detector is superior to both photomultipliers and photodiodes, although it does not require cryogenic cooling of any component. The position of this photon flux window sensitively depends on the parameters of the actual experimental implementation (desired bandwidth, detector size, etc.) Several detector units based on these developments have been built and installed in various tokamaks. Some illustrative results are presented from the 8-channel trial BES system installed at Mega-Ampere Spherical Tokamak (MAST) and the 16-channel BES system installed at the Torus Experiment for Technology Oriented Research (TEXTOR).

  16. Design and proposal of dual line-of-defense perimeter watchdog incorporating optimally designed FBG based accelerometers and strain sensors using single optical fiber

    NASA Astrophysics Data System (ADS)

    Khan, Mohd. Mansoor; Sonkar, Ramesh Kumar

    2015-06-01

    Paper presents Opto-Mechanical intrusion sensor fence with FBGs attached to mechanical accelerometers and strain sensors, optimized on SolidWorks 2013 for desired frequency to 35 Hz, picking up accelerations/ strains and its deployment for perimeter security. The accelerometer structure consists of inertial mass supported by an L-shaped modified cantilever beam having non-uniform cross section area connected to base by a thin neck element which acts as strain concentrated centre hence an optimum zone for FBG sensors placement. Bragg wavelength shifts were obtained on Optigrating software for the obtained strain values on mechanical assembly of fence. CFD wind analysis is performed on the assembly to obtain the spot for accelerometer's placement to avoid false alarms up to wind velocities of 20 m/s.

  17. Two-color beam generation based on wakefield excitation

    NASA Astrophysics Data System (ADS)

    Bettoni, S.; Prat, E.; Reiche, S.

    2016-05-01

    Several beam manipulation methods have been studied and experimentally tested to generate two-color photon beams in free electron laser facilities to accommodate the user requests. We propose to use the interaction of the beam with an oscillating longitudinal wakefield source to obtain a suitable electron beam structure. The bunch generates two subpulses with different energies and delayed in time passing through a magnetic chicane after its longitudinal phase space has been modulated by the wakefield source. According to this approach the power of the emitted radiation is not degraded compared to the monochromatic beam, and the setup in the machine is quite simple because the bunch is manipulated only in the high energy section, where it is more rigid. We present the design applied to SwissFEL. We identified the parameters and the corresponding range of tunability of the time and energy separation among the two subbunches.

  18. Beam lifetime study based on momentum acceptance restriction by movable beam scraper

    NASA Astrophysics Data System (ADS)

    Kaneyasu, T.; Takabayashi, Y.; Iwasaki, Y.; Koda, S.

    2012-12-01

    The beam lifetime of the SAGA-LS electron storage ring was experimentally investigated using a movable beam scraper installed in a dispersive section. In addition to physical aperture restriction, the scraper could be used to reduce the momentum acceptance of the storage ring, enabling the evaluation of the Touschek effect. Lifetime measurements were performed with scraper scans, and the individual contributions of gas scattering and the Touschek effect were clarified. Our results confirm that the present method provides a basic understanding of lifetime limiting effects in the storage ring.

  19. Comparison of cone beam artifacts reduction: two pass algorithm vs TV-based CS algorithm

    NASA Astrophysics Data System (ADS)

    Choi, Shinkook; Baek, Jongduk

    2015-03-01

    In a cone beam computed tomography (CBCT), the severity of the cone beam artifacts is increased as the cone angle increases. To reduce the cone beam artifacts, several modified FDK algorithms and compressed sensing based iterative algorithms have been proposed. In this paper, we used two pass algorithm and Gradient-Projection-Barzilai-Borwein (GPBB) algorithm to reduce the cone beam artifacts, and compared their performance using structural similarity (SSIM) index. In two pass algorithm, it is assumed that the cone beam artifacts are mainly caused by extreme-density(ED) objects, and therefore the algorithm reproduces the cone beam artifacts(i.e., error image) produced by ED objects, and then subtract it from the original image. GPBB algorithm is a compressed sensing based iterative algorithm which minimizes an energy function for calculating the gradient projection with the step size determined by the Barzilai- Borwein formulation, therefore it can estimate missing data caused by the cone beam artifacts. To evaluate the performance of two algorithms, we used testing objects consisting of 7 ellipsoids separated along the z direction and cone beam artifacts were generated using 30 degree cone angle. Even though the FDK algorithm produced severe cone beam artifacts with a large cone angle, two pass algorithm reduced the cone beam artifacts with small residual errors caused by inaccuracy of ED objects. In contrast, GPBB algorithm completely removed the cone beam artifacts and restored the original shape of the objects.

  20. Assessment of flatness and symmetry of megavoltage x-ray beam with an electronic portal imaging device (EPID).

    PubMed

    Liu, G; van Doorn, T; Bezak, E

    2002-07-01

    The input/output characteristics of the Wellhofer BIS 710 electronic portal imaging device (EPID) have been investigated to establish its efficacy for periodic quality assurance (QA) applications. Calibration curves have been determined for the energy fluence incident on the detector versus the pixel values. The effect of the charge coupled device (CCD) camera sampling time and beam parameters (such as beam field size, dose rate, photon energy) on the calibration have been investigated for a region of interest (ROI) around the central beam axis. The results demonstrate that the pixel output is a linear function of the incident exposure, as expected for a video-based electronic portal imaging system. The field size effects of the BIS 710 are similar to that of an ion chamber for smaller field sizes up to 10 x 10 cm2. However, for larger field sizes the pixel value increases more rapidly. Furthermore, the system is slightly sensitive to dose rate and is also energy dependent The BIS 710 has been used in the current study to develop a QA procedure for measurements of flatness and symmetry of a linac x-ray beam. As a two-dimensional image of the radiation field is obtained from a single exposure of the BIS 710, a technique has been developed to calculate flatness and symmetry from a defined radiation area. The flatness and symmetry values obtained are different from those calculated conventionally from major axes only (inplane, crossplane). This demonstrates that the technique can pick up the "cold" and "hot" spots in the analysed area, providing thus more information about the radiation beam. When calibrated against the water tank measurements, the BIS 710 can be used as a secondary device to monitor the x-ray beam flatness and symmetry. PMID:12219846

  1. Experimental analysis of beam pointing system based on liquid crystal optical phase array

    NASA Astrophysics Data System (ADS)

    Shi, Yubin; Zhang, Jianmin; Zhang, Zhen

    2016-06-01

    In this paper, we propose and demonstrate an elementary non-mechanical beam aiming and steering system with a single liquid crystal optical phase array (LC-OPA) and charge-coupled device (CCD). With the conventional method of beam steering control, the LC-OPA device can realize one dimensional beam steering continuously. An improved beam steering strategy is applied to realize two dimensional beam steering with a single LC-OPA. The whole beam aiming and steering system, including an LC-OPA and a retroreflective target, is controlled by the monitor. We test the feasibility of beam steering strategy both in one dimension and in two dimension at first, then the whole system is build up based on the improved strategy. The experimental results show that the max experimental pointing error is 56 µrad, and the average pointing error of the system is 19 µrad.

  2. Radiative damping and electron beam dynamics in plasma-based accelerators.

    PubMed

    Michel, P; Schroeder, C B; Shadwick, B A; Esarey, E; Leemans, W P

    2006-08-01

    The effects of radiation reaction on electron beam dynamics are studied in the context of plasma-based accelerators. Electrons accelerated in a plasma channel undergo transverse betatron oscillations due to strong focusing forces. These oscillations lead to emission by the electrons of synchrotron radiation, with a corresponding energy loss that affects the beam properties. An analytical model for the single particle orbits and beam moments including the classical radiation reaction force is derived and compared to the results of a particle transport code. Since the betatron amplitude depends on the initial transverse position of the electron, the resulting radiation can increase the relative energy spread of the beam to significant levels (e.g., several percent). This effect can be diminished by matching the beam into the channel, which could require micron sized beam radii for typical values of the beam emittance and plasma density. PMID:17025550

  3. Bernoulli Euler beam model based on a modified couple stress theory

    NASA Astrophysics Data System (ADS)

    Park, S. K.; Gao, X.-L.

    2006-11-01

    A new model for the bending of a Bernoulli-Euler beam is developed using a modified couple stress theory. A variational formulation based on the principle of minimum total potential energy is employed. The new model contains an internal material length scale parameter and can capture the size effect, unlike the classical Bernoulli-Euler beam model. The former reduces to the latter in the absence of the material length scale parameter. As a direct application of the new model, a cantilever beam problem is solved. It is found that the bending rigidity of the cantilever beam predicted by the newly developed model is larger than that predicted by the classical beam model. The difference between the deflections predicted by the two models is very significant when the beam thickness is small, but is diminishing with the increase of the beam thickness. A comparison shows that the predicted size effect agrees fairly well with that observed experimentally.

  4. Fluorescence-based video profile beam diagnostics: Theory and experience

    SciTech Connect

    Sandoval, D.P.; Garcia, R.C.; Gilpatrick, J.D.; Shinas, M.A.; Wright, R.; Yuan, V.; Zander, M.E. )

    1994-10-10

    Inelastic collisions between accelerated particles and residual gas in the accelerator vessel can cause the residual gas to fluoresce. The gas fluorescence intensity is proportional to the current density of the particle beam. This process provides the foundation for a video diagnostics system to measure the profile and position of accelerated particle beams. This, in fact, has proven to be a useful diagnostic at several installations. This paper describes the light production process resulting from beam-residual gas interactions and gives formulas for estimating the beam radiance for various conditions. Ground Test Accelerator (GTA) radiance calculations will be used as an example. In addition, measurement experiences with the GTA video diagnostics system will be discussed.

  5. UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC

    SciTech Connect

    Bakeman, M.S.; Fawley, W.M.; Leemans, W. P.; Nakamura, K.; Robinson, K.E.; Schroeder, C.B.; Toth, C.

    2009-05-04

    to couple the THUNDER undulator to the LOASIS Lawrence Berkeley National Laboratory (LBNL) laser wakefield accelerator (LWFA). Currently the LWFA has achieved quasi-monoenergetic electron beams with energies up to 1 GeV. These ultra-short, high-peak-current, electron beams are ideal for driving a compact XUV free electron laser (FEL). Understanding the electron beam properties such as the energy spread and emittance is critical for achieving high quality light sources with high brightness. By using an insertion device such as an undulator and observing changes in the spontaneous emission spectrum, the electron beam energy spread and emittance can be measured with high precision. The initial experiments will use spontaneous emission from 1.5 m of undulator. Later experiments will use up to 5 m of undulator with a goal of a high gain, XUV FEL.

  6. Terahertz radiation source based on self-wake beam bunching

    SciTech Connect

    Antipov, Sergey; Jing Chunguang; Schoessow, Paul; Kanareykin, Alexei; Jiang Bo; Yakimenko, Vitaly; Zholents, Alexander; Gai Wei

    2012-12-21

    A table top device for producing high power T-ray beams is described. A rectangular electron beam that can be produced out of a photoinjector via stacking of the laser pulse, and running off-crest of the photoinjector rf is sent through a dielectric loaded waveguide. Due to the beam's self-wake its energy becomes modulated. In the chicane beamline following the dielectric energy-bunching section this energy modulation is converted to a density modulation-a bunch train. The density modulated beam can be sent through a power extraction section, like a dielectric loaded accelerating structure, or simply can intercept a foil target, producing THz radiation of various bandwidths and power levels.

  7. Fluorescence-based video profile beam diagnostics: Theory and experience

    SciTech Connect

    Sandoval, D.; Gilpatrick, D.; Shinas, M.; Garcia, R.; Yuan, V.; Zander, M.

    1994-05-01

    Inelastic collisions between accelerated particles and residual gas in the accelerator vessel can cause the residual gas to fluoresce. The gas fluorescence intensity is proportional to the current density of the particle beam. This process provides the foundation for a video diagnostic system to measure the profile and position of accelerated particle beams. This, in fact, has proven to be a useful diagnostic at several installations. This paper describes the light production process resulting from beam -- residual gas interactions and gives formulas for estimating the beam radiance for various conditions. Ground Test Accelerator (GTA) radiance calculations will be used as an example. In addition, measurement experiences with the GTA video diagnostics system will be discussed.

  8. A microprocessor-based beam sweep control unit

    NASA Astrophysics Data System (ADS)

    Conrad, R.; Mertens, P.

    1981-10-01

    Using a microprocessor a beam sweep control module has been developed that facilitates ion beam experiments or ion implantation at a constant ion beam density. The density is regulated by varying the amplitude of an x- y-deflection system. The control unit supplies an analogue output voltage which is employed to adjust this amplitude. In our experiment a commercially available DANFYSIK Model 730 beam sweep system has been modified to enable external amplitude control. The control unit can be operated manually or by computer support. In any case the initial ion beam density and ion dose are to be set manually. Four functions (START, STOP, RESET, optional: SHUTTER) are controlled via push buttons or external signals. Coincident with the START-signal the shutter is opened. The ion charge on the target is now accumulated for 10 s. If deviations larger than 2% full scale from the initial beam density are measured the analogue output voltage of the control unit is changed. In case the initial value cannot be regulated within a limited voltage range, a warning is given (lamp and level). Under normal operation the shutter is closed when the preset ion dose has been accumulated. The control unit is manufactured in a standard NIM housing (four units) and has the following features: analogue instruments for (1) ion current and (2) deviation between initial and actual ion current, (3) three digits and one exponent to preset the ion charge, digital displays for (4) accumulated ion charge and (5) time, and (6) a potentiometer to set the initial control voltage, i.e. the ion beam density. The combination of these features together with the simple three - pushbutton - operation makes the instrument a very versatile tool for ion beam experiments.

  9. Metal etching with reactive gas cluster ion beams using pickup cell

    SciTech Connect

    Toyoda, Noriaki; Yamada, Isao

    2012-11-06

    Mixed gas cluster ion beams were formed using pickup cell for metal etching. O{sub 2} neutral clusters pick up acetic acid and formed mixed cluster beam. By using O{sub 2}-GCIB with acetic acid, enhancement of Cu etching was observed. Because of dense energy deposition by GCIB, etching of Cu proceeds by CuO formation, enhancement of chemical reaction with acetic acid and desorption of etching products. Surface roughening was not observed on poly crystalline Cu because of the small dependence of etching rate on crystal orientation. Halogen free and low-temperature metal etching with GCIB using pickup cell is possible.

  10. BEAM-BASED ALIGNMENT IN THE RHIC E-COOLING SOLENOIDS.

    SciTech Connect

    CAMERON, P.; BEN-ZVI, I.; DAWSON, W.C.; ET AL.

    2005-05-16

    Accurate alignment of the electron and ion beams in the RHIC electron cooling solenoids is crucial for well-optimized cooling. Because of the greatly differing rigidities of the electron and ion beams, to achieve the specified alignment accuracy it is required that transverse magnetic fields resulting from imperfections in solenoid fabrication be down by five orders of magnitude relative to the pure solenoid fields. Shimming the solenoid field to this accuracy might be accomplished by survey techniques prior to operation with beam, or by methods of beam-based alignment. We report on the details of a method of beam-based alignment, as well as the results of preliminary measurements with the ion beam at RHIC.