Summary of Fermilab's Recycler Electron Cooler Operation and Studies

Fermilab's Recycler ring was used as a storage ring for accumulation and subsequent manipulations of 8-GeV antiprotons destined for the Tevatron collider. To satisfy these missions, a unique electron cooling system was designed, developed and successfully implemented. The most important features that distinguish the Recycler cooler from other existing electron coolers are its relativistic energy (it employs a 4.3 MeV, 0.1 A DC electron beam), a weak continuous longitudinal magnetic field in the cooling section (~100 G), and lumped focusing elsewhere. With the termination of the collider operation at Fermilab, the cooler operation was also terminated. In this article, we will summarize the experience of commissioning, optimizing and running this unique machine over the 6 years of its existence.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012) 20-25 May 2012. New Orleans, Louisian

The State of the Art in Hadron Beam Cooling

Cooling of hadron beams (including heavy-ions) is a powerful technique by which accelerator facilities around the world achieve the necessary beam brightness for their physics research. In this paper, we will give an overview of the latest developments in hadron beam cooling, for which high energy electron cooling at Fermilab's Recycler ring and bunched beam stochastic cooling at Brookhaven National Laboratory's RHIC facility represent two recent major accomplishments. Novel ideas in the field will also be introduced.Comment: 7 pages, 7 figures, ICFA-HB2008 Invited presentatio

Determination of the pure silicon monocarbide content of silicon carbide and products based on silicon carbide

Experience has shown that different methods of analysis of SiC products give different results. Methods identified as AFNOR, FEPA, and manufacturer P, currently used to detect SiC, free C, free Si, free Fe, and SiO2 are reviewed. The AFNOR method gives lower SiC content, attributed to destruction of SiC by grinding. Two products sent to independent labs for analysis by the AFNOR and FEPA methods showed somewhat different results, especially for SiC, SiO2, and Al2O3 content, whereas an X-ray analysis showed a SiC content approximately 10 points lower than by chemical methods

Classroom, club or collective? Three types of community-based group intervention and why they matter for health

Interventions involving groups of laywomen, men and adolescents to promote health are increasingly popular, but past research has rarely distinguished between different types of intervention with groups. We introduce a simple typology that distinguishes three ideal types: classrooms, clubs and collectives. Classrooms treat groups as a platform for reaching a population with didactic behaviour change strategies. Clubs seek to build, strengthen and leverage relationships between group members to promote health. Collectives engage whole communities in assuming ownership over a health problem and taking action to address it. We argue that this distinction goes a long way towards explaining differences in achievable health outcomes using interventions with groups. First, classrooms and clubs are appropriate when policymakers primarily care about improving the health of group members, but collectives are better placed to achieve population-level impact. Second, classroom interventions implicitly assume bottleneck behaviours preventing a health outcome from being achieved can be reliably identified by experts, whereas collectives make use of local knowledge, skill and creativity to tackle complexity. Third, classroom interventions assume individual participants can address health issues largely on their own, while clubs and collectives are required to engender collective action in support of health. We invite public health researchers and policymakers to use our framework to align their own and communities’ ambitions with appropriate group-based interventions to test and implement for their context. We caution that our typology is meant to apply to groups of laypeople rather than professionalised groups such as whole civil society organisations

Geologic and mineral and water resources investigations in western Colorado, using Skylab EREP data

The author has identified the following significant results. Skylab photographs are superior to ERTS images for photogeologic interpretation, primarily because of improved resolution. Lithologic contacts can be detected consistently better on Skylab S190A photos than on ERTS images. Color photos are best; red and green band photos are somewhat better than color-infrared photos; infrared band photos are worst. All major geologic structures can be recognized on Skylab imagery. Large folds, even those with very gentle flexures, can be mapped accurately and with confidence. Bedding attitudes of only a few degrees are recognized; vertical exaggeration factor is about 2.5X. Mineral deposits in central Colorado may be indicated on Skylab photos by lineaments and color anomalies, but positive identification of these features is not possible. S190A stereo color photography is adequate for defining drainage divides that in turn define the boundaries and distribution of ground water recharge and discharge areas within a basin

Transverse instability of the antiproton beam in the Recycler Ring

The brightness of the antiproton beam in Fermilab's 8 GeV Recycler ring is limited by a transverse instability. This instability has occurred during the extraction process to the Tevatron for large stacks of antiprotons even with dampers in operation. This paper describes observed features of the instability, introduces the threshold phase density to characterize the beam stability, and finds the results to be in agreement with a resistive wall instability model. Effective exclusion of the longitudinal tails from Landau damping by decreasing the depth of the RF potential well is observed to lower the threshold density by up to a factor of two.Comment: 3 pp. Particle Accelerator, 24th Conference (PAC'11) 2011. 28 Mar - 1 Apr 2011. New York, US