1,065 research outputs found
Alignment and Aperture Scan at the Fermilab Booster
The Fermilab booster has an intensity upgrade plan called the Proton
Improvement plan (PIP). The flux throughput goal is 2E17 protons/hour, which is
almost double the current operation at 1.1E17 protons/hour. The beam loss in
the machine is going to be the source of issues. The booster accelerates beam
from 400 MeV to 8 GeV and extracts to the Main Injector. Several percent of the
beam is lost within 3 msec after the injection. The aperture at injection
energy was measured and compared with the survey data. The magnets are going to
be realigned in March 2012 in order to increase the aperture. The beam studies,
analysis of the scan and alignment data, and the result of the magnet moves
will be discussed in this paper.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012)
20-25 May 2012, New Orleans, Louisian
Mars mission solar array Semiannual progress report, period ending 31 Dec. 1969
Design and testing of beryllium-structure solar panel for Mars missio
Atomic resolution scanning tunneling microscopy images of Au(111) surfaces in air and polar organic solvents
Atomic features of a closeâpacked metal surface have been observed for the first time by scanning tunneling microscopy in organic polar solvents. Evaporated gold films, exhibiting large reconstructed (111) terraces, have been imaged with a resolution far superior to previous results in aqueous environments
RXTE Monitoring of the Anomalous X-ray Pulsar 1E 1048.1-5937
We report on long-term monitoring of the anomalous X-ray pulsar 1E
1048.1-5937 using the Rossi X-ray Timing Explorer. This pulsar's timing
behavior is different from that of other AXPs. In particular, the pulsar shows
significant deviations from simple spin-down such that phase-coherent timing
has not been possible over time spans longer than a few months. We show that in
spite of the rotational irregularities, the pulsar exhibits neither pulse
profile changes nor large pulsed flux variations. We discuss the implications
of our results for AXP models. We suggest that 1E 1048.1-5937 may be a
transition object between the soft gamma-ray repeater and AXP populations, and
the AXP most likely to one day undergo an outburst.Comment: 6 pages, to appear in Proceedings of the 20th Texas Symposium on
Relativistic Astrophysics, AIP pres
Elgin on understanding:How does it involve know-how, endorsement and factivity?
In Chapter 3 of True Enough, Elgin (2017) outlines her view of objectual understanding, focusing largely on its non-factive nature and the extent to which a certain kind of know-how is required for the âgraspingâ component of understanding. I will explore four central issues that feature in this chapter, concentrating on (1) the role of know-how, (2) the concept of endorsement, (3) Elginâs critique of the factivity constraint on understanding, and (4) how we might use aspects of Elginâs framework to inform related debates on the norm of assertion
A Detailed Record of Shallow Hydrothermal Fluid Flow in the Sierra Nevada Magmatic Arc from Low-δ18O Skarn Garnets
Garnet from skarns exposed at Empire Mountain, Sierra Nevada (California, United States) batholith, have variable δ18O values including the lowest known δ18O values of skarn garnet (â4.0â°) in North America. Such values indicate that surface-derived meteoric water was a significant component of the fluid budget of the skarn-forming hydrothermal system, which developed in response to shallow emplacement (âź3.3 km) of the 109 Ma quartz diorite of Empire Mountain. Values of δ18O, measured in situ across single garnet crystals by secondary ion mass spectrometry, vary considerably (up to 7â°) and sometimes abruptly, indicating variable mixing of meteoric, magmatic, and metamorphic water. Brecciation in the skarns and alteration of the Empire Mountain pluton suggests that fracture-enhanced permeability was a critical control on the depth to which surface waters penetrated to form skarns and later alter the pluton. Compared to other Sierran systems, much greater volumes of skarn rock suggest an exceptionally vigorous hydrothermal system that saw unusually high levels of decarbonation reaction progress, likely a consequence of the magma intruding relatively cold wallrocks inboard of the main locus of magmatism in the Sierran arc at that time
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