469 research outputs found
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Measurement of Beam Tunes in the Tevatron Using the BBQ System
Measuring the betatron tunes in any synchrotron is of critical importance to ensuring the stability of beam in the synchrotron. The Base Band Tune, or BBQ, measurement system was developed by Marek Gasior of CERN and has been installed at Brookhaven and Fermilab as a part of the LHC Accelerator Research Program, or LARP. The BBQ was installed in the Tevatron to evaluate its effectiveness at reading proton and antiproton tunes at its flattop energy of 980 GeV. The primary objectives of this thesis are to examine the methods used to measure the tune using the BBQ tune measurement system, to incorporate the system into the Fermilab accelerator controls system, ACNET, and to compare the BBQ to existing tune measurement systems in the Tevatron
Refining victimsâ self-reports on bullying:Assessing frequency, intensity, power imbalance, and goal-directedness
Bullying can be differentiated from other types of peer aggression by four key characteristics: frequency, intensity, power imbalance, and goalâdirectedness. Existing instruments, however, usually assess the presence of these characteristics implicitly. Can selfâreport instruments be refined using additional questions that assess each characteristic? We examined (a) what proportion of children classified as victims by the commonly used Revised Olweusâ bully/victim questionnaire (BVQ) also experienced the characteristics of bullying, and (b) the extent to which the presence of the characteristics was associated with emotional (affect, school, and classroom wellâbeing), relational (friendship, defending), and social status (popularity, rejection) adjustment correlates among victims. Using data from 1,738 students (Mage = 10.6; grades 5â8), including 138 victims according to the BVQ, the results showed that 43.1% of the children who were classified as victims by BVQ experienced all the four characteristics of bullying. Frequency ratings of victimization did not capture experiences that involved a power imbalance. Victims who reported all four key characteristics had greater emotional, relational, and social status problems than victims who did not report all characteristics. Thus, researchers who focus on victimization for diagnostic and prevention purposes can enrich selfâreport measurements of bullying victimization by adding questions that assess the characteristics explicitly
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The PEACE PIPE: Recycling nuclear weapons into a TRU storage/shipping container
This paper describes results of a contract undertaken by the National Conversion Pilot Project (NCPP) at the Rocky Flats Environmental Technology Site (RFETS) to fabricate stainless steel ``pipe`` containers for use in certification testing at Sandia National Lab, Albuquerque to qualify the container for both storage of transuranic (TRU) waste at RFETS and other DOE sites and shipping of the waste to the Waste Isolation Pilot Project (WIPP). The paper includes a description of the nearly ten-fold increase in the amount of contained plutonium enabled by the product design, the preparation and use of former nuclear weapons facilities to fabricate the components, and the rigorous quality assurance and test procedures that were employed. It also describes how stainless steel nuclear weapons components can be converted into these pipe containers, a true ``swords into plowshare`` success story
Submacropulse electron-beam dynamics correlated with higher-order modes in a Tesla-type cryomodule
Experiments were performed at the Fermilab Accelerator Science and Technology
(FAST) facility to elucidate the effects of long-range wakefields (LRWs) in
TESLA-type superconducting rf cavities. In particular, we investigated the
higher-order modes (HOMs) generated in the eight cavities of a cryomodule (CM)
due to off-axis steering with correctors located ~4 m upstream of the CM. We
have observed correlated submacropulse centroid slews of a few-hundred microns
and centroid oscillations at ~240 kHz in the rf BPM data after the CM. The
entrance energy into the CM was 25 MeV, and the exit energy was 100 MeV with
125 pC/b and 400 pC/b in 50-bunch pulse trains. These experimental results were
evaluated for machine learning training aspects which will be used to inform
the commissioning plan for the Linac Coherent Light Source-II injector CM
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