Debuncher Cooling Performance

Abstract. We present measurements of the Fermilab Debuncher momentum and transverse cooling systems. These systems use liquid helium cooled waveguide pickups and slotted waveguide kickers covering the frequency range 4-8 GHz. Keywords: Stochastic Cooling, Antiproton Beams PACS: 41.75.Lx THE FERMILAB DEBUNCHER The Fermilab Debuncher is an 8 GeV ring designed for the collection, RF debunching, and storage of anitprotons. The Tevatron Collider program requires 1e13 antiprotons for the study of proton-antiproton collisions at √ s = 1.96 TeV. Antiprotons are produced by impinging a 120 GeV proton beam on an nickel alloy target and collected through a lithium focussing lens and the Debuncher ring then stochastic stacked in the Fermilab Accumulator PERFORMANCE REQUIREMENTS The Debuncher accepts a few ×10 8 antiprotons every 2 seconds. The input beam fills the transverse aperture of the beam, consistent with a transverse emittance of 320π mm mr (95% unnormalized). At the end of the 2 second cycle, the beam is required to have transverse emittance less than 45π mm mr (95% unnormalized) in both planes (factor of 7). After bunch rotation, the 95% momentum width is approximately 60 MeV/c. At the end of the 2 second cycle, the 95% momentum width of the beam is required to be less than 6 MeV/c (factor of 10). These requirements correspond to a 6-dimensional phase space density (ρ 6d = N particles ε l ε h ε v ) increase of a factor of 500

Debuncher cooling performance

We present measurements of the Fermilab Debuncher momentum and transverse cooling systems. These systems use liquid helium cooled waveguide pickups and slotted waveguide kickers covering the frequency range 4-8 GHz

Genetically determined P2X7 receptor pore formation regulates variability in chronic pain sensitivity

Chronic pain is highly variable between individuals, as is the response to analgesics. Although much of the variability in chronic pain and analgesic response is heritable, an understanding of the genetic determinants underlying this variability is rudimentary1. Here we show that variation within the coding sequence of the gene encoding the P2X7 receptor (P2X7R) affects chronic pain sensitivity in both mice and humans. P2X7Rs, which are members of the family of ionotropic ATP-gated receptors, have two distinct modes of function: they can function through their intrinsic cationic channel or by forming nonselective pores that are permeable to molecules with a mass of up to 900 Da2,3. Using genome-wide linkage analyses, we discovered an association between nerve-injury–induced pain behavior (mechanical allodynia) and the P451L mutation of the mouse P2rx7 gene, such that mice in which P2X7Rs have impaired pore formation as a result of this mutation showed less allodynia than mice with the pore-forming P2rx7 allele. Administration of a peptide corresponding to the P2X7R C-terminal domain, which blocked pore formation but not cation channel activity, selectively reduced nerve injury and inflammatory allodynia only in mice with the pore-forming P2rx7 allele. Moreover, in two independent human chronic pain cohorts, a cohort with pain after mastectomy and a cohort with osteoarthritis, we observed a genetic association between lower pain intensity and the hypofunctional His270 (rs7958311) allele of P2RX7. Our findings suggest that selectively targeting P2X7R pore formation may be a new strategy for individualizing the treatment of chronic pain

Eigenvalue asymptotics for normalized Sturm-Liouville problems

Includes bibliographical references (leaf [53]).In this thesis, we obtain asymptotic formulas for eigenvalues associated with the Liouville Normal Form of the general Sturm-Liouville equation (pu')' + (λk — Q)u=0 on the interval [a, b]. The method used is based on an iterative procedure for solving the associated Riccati equation and then developing an asymptotic ex- 1 pansion of the solution in decending powers of λ^(1/2) as A —» ∞. The eigenvalue asymptotic formulas are then found using series reversion. Examples of this process are carried out by the symbolic manipulator package, MAPLE.M.S. (Master of Science

Addressing the Petersen graph

In a 1971 paper motivated by a problem on message routing in a communications network, Graham and Pollack propose a scheme for addressing the vertices of a graph G by N-tuples of three symbols in such a way that distances between vertices may readily be determined from their addresses. They observe that N h(D), the maximum of the number of positive and the number of negative eigenvalues of the distance matrix D of G. A result from a paper of Gregory, Shader and Watts (1999) yields a necessary condition for equality to occur. As an illustration, it is shown here that N ? h(D) = 5 for all addressings of the Petersen graph. Also, an optimal addressing of the Petersen graph by 6-tuples is given. MSC: 05C50, 05C20 Keywords: Eigenvalues; Addressing; Distance matrix Throughout the paper, G will always denote a finite, connected, simple graph with vertices 1; 2; : : : ; n and n \Theta n adjacency matrix A. Terminology not defined here may be found in the book by van Lint and Wilso..

Inertia and Biclique Decompositions of Joins of Graphs

this paper, we present some general results on partial joins and then provide classes of graphs which may be used to form joins G with b(G) = h(G) = n- (G