11,897 research outputs found
Non-invasive single-bunch matching and emittance monitor
On-line monitoring of beam quality for high brightness beams is only possible
using non-invasive instruments. For matching measurements, very few such
instruments are available. One candidate is a quadrupole pick-up. Therefore, a
new type of quadrupole pick-up has been developed for the 26 GeV Proton
Synchrotron (PS) at CERN, and a measurement system consisting of two such
pick-ups is now installed in this accelerator. Using the information from these
pick-ups, it is possible to determine both injection matching and emittance in
the horizontal and vertical planes, for each bunch separately. This paper
presents the measurement method and some of the results from the first year of
use, as well as comparisons with other measurement methods.Comment: 10 pages, 10 figures; added figure, minor textual additions; To be
resubmitted to Phys. Rev. ST-A
An Analysis of Kinetic Response Variability
Studies evaluating variability of force as a function of absolute force generated are synthesized. Inconsistencies in reported estimates of this relationship are viewed as a function of experimental constraints imposed. Typically, within-subject force variability increases at a negative accelerating rate with equal increments in force produced. Current pulse-step and impulse variability models are unable to accommodate this description, although the notion of efficiency is suggested as a useful construct to explain the description outlined
Sensation Seeking and Perceived Need for Structure Moderate Soldiers’ Well-Being Before and After Operational Deployment
This study examined associations between sensation seeking and perceived need for structure, and changes in reported well-being among deployed soldiers. Participants (n = 167) were assessed before and after a six-month deployment to south Afghanistan. Results indicated that although well-being declined in the soldier sample as a whole following deployment, the degree of decrease was significantly different among soldiers with different personality profiles. Differences were moderated by soldiers’ level of sensation seeking and perceived need for structure. Results are discussed in terms of a person-environment fit theory in the context of preparation and rehabilitation of deployed military personnel
Tomographic reconstruction of transverse phase space from turn-by-turn profile data
Tomographic methods have the potential for useful application in beam diagnostics. The tomographic reconstruction of transverse phase space density from turn-by-turn profile data has been studied with particular attention to the effects of dispersion and chromaticity. It is shown that the modified Algebraic Reconstruction Technique (ART) that deals successfully with the problem of non-linear motion in the longitudinal plane cannot, in general, be extended to cover the transverse case. Instead, an approach is proposed in which the effect of dispersion is deconvoluted from the measured profiles before the phase space picture is reconstructed using either the modified ART algorithm or the inverse Radon Transform. This requires an accurate knowledge of the momentum distribution of the beam and the modified ART reconstruction of longitudinal phase space density yields just such information. The method has been tested extensively with simulated data
Studies of CMB structure at Dec=40. II: Analysis and cosmological interpretation
We present a detailed analysis of the cosmic microwave background structure
in the Tenerife Dec=+40 degrees data. The effect of local atmospheric
contributions on the derived fluctuation amplitude is considered, resulting in
an improved separation of the intrinsic CMB signal from noise. Our analysis
demonstrates the existence of common structure in independent data scans at 15
and 33 GHz. For the case of fluctuations described by a Gaussian
auto-correlation function, a likelihood analysis of our combined results at 15
and 33 GHz implies an intrinsic rms fluctuation level of 48^{+21}_{-15} uK on a
coherence scale of 4 degrees; the equivalent analysis for a
Harrison-Zel'dovitch model gives a power spectrum normalisation of Q_{rms-ps} =
22^{+10}_{-6} uK. The fluctuation amplitude is seen to be consistent at the 68%
confidence level with that reported for the COBE two-year data for primordial
fluctuations described by a power law model with a spectral index in the range
1.0 \le n \le 1.6. This limit favours the large scale CMB anisotropy being
dominated by scalar fluctuations rather than tensor modes from a gravitational
wave background. The large scale Tenerife and COBE results are considered in
conjunction with observational results from medium scale experiments in order
to place improved limits on the fluctuation spectral index; we find n=1.10 +/-
0.10 assuming standard CDM with H_{0}=50 kms^{-1}Mpc^{-1}.Comment: 10 pages LaTeX, including 8 PostScript figures. Accepted for
publication in MNRA
PRODUCER ACCEPTANCE OF A NEW PEANUT MARKETING COOPERATIVE: A SURVEY OF GEORGIA PEANUT PRODUCERS
Market conduct has become an important issue for peanut farmers. Consolidation in the first buyer market, increased imports, and political uncertainty have increased peanut producers' marketing risks. The purpose of this paper was to examine demographic differences in peanut producers' perceptions of the current marketing environment as well as their attitudes towards new marketing institutions. A standard t-test revealed that producers growing more than 250 acres of peanuts, irrigating at least 50 percent of their peanuts, and producers located in Southwest Georgia were statistically more dissatisfied with the current marketing environment and significantly more receptive to forming a new generation peanut cooperative.Agribusiness, Crop Production/Industries,
A NEW GENERATION PEANUT COOPERATIVE IN GEORGIA: A BENEFIT-COST ANALYSIS
A survey of Georgia peanut producers revealed that the Southwest corner of Georgia could be targeted for a new generation peanut cooperative (FS 01-07). The objective of this study was to examine the feasibility of this option. Preliminary results revealed that this might be an economically feasible solution to peanut producers' marketing problems. The projected discounted benefit-cost ratios ranged from 1.9 to 1.4 over a ten-year period.Agribusiness, Crop Production/Industries,
- …