6939093
CESR-C Wiggler Studies in the Context of the International Linear Collider Damping Rings
We present a picture of the International Linear Collider (ILC) damping ring wiggler dynamics using the experience gained from the experimental and simulation-based research studying the wigglers used in the current configuration of the Cornell Electron Storage Ring (CESR). CESR is currently running at 1.8 GeV with 12 superconducting wigglers that have been designed, fabricated, tested, and simulated on-site. We will present results which include frequency map analyses and conventional dynamic aperture studies of CESR-c and the ILC damping rings. We will also provide results from an initial look at physical limitations in the design of the ILC damping ring wigglers.
117436641
An optimized superferric wiggler design for the International Linear Collider damping rings
54752538
OPTIMIZATION OF CESR-C SUPERFERRIC WIGGLER FOR THE INTERNATIONAL LINEAR COLLIDER DAMPING RINGS ∗
We present the results of an optimization of the Cornell Electron Storage Ring (CESR) superferric wiggler for the International Linear Collider (ILC) damping ring. The superferric CESR wiggler has been shown to have excellent beam dynamics properties in the ILC damping ring. We reduced the physical size, and hence cost, of the CESR wiggler with minimal degradation of ILC damping ring beam dynamics. We will provide a description of the optimized superferric wiggler and show the performance of this wiggler in the ILC baseline damping ring.
22472590
Design considerations and modeling results for ILC damping ring wigglers based on the CESR-C superconducting wiggler
The international linear collider (ILC) damping rings will require construction of wiggler magnets of high field quality on a large scale. We consider various designs derived from the wigglers presently in operation at the Cornell electron storage ring (CESR). Design optimization has been performed based on detailed tracking calculations of dynamic aperture and tune footprint in a full model of the damping ring. Results on finite-element modelling, transfer functions, and implications for the final engineering design will be discussed.
14763393
An International Ultraviolet Explorer Archival Study of Dwarf Novae in Outburst
We present a synthetic spectral analysis of nearly the entire far-ultraviolet International Ultraviolet Explorer (IUE) archive of spectra of dwarf novae in or near outburst. The study includes 46 systems of all dwarf nova subtypes, both above and below the period gap. The spectra were uniformly analyzed using synthetic spectral codes for optically thick accretion disks and stellar photospheres, along with the best available distance measurements or estimates. We present newly estimated accretion rates and discuss the implications of our study for disk accretion physics and CV evolution.
1434460
The Dwarf Novae during Quiescence
We present a synthetic spectral analysis of nearly the entire far-ultraviolet (FUV) IUE archive of spectra of dwarf novae (DNe) in or near their quiescence. We have examined all of the systems for which the signal-to-noise ratio permitted an analysis. The study includes 53 systems of all DN subtypes both above and below the period gap. The spectra were uniformly analyzed using synthetic spectral codes for optically thick accretion disks and stellar photospheres, along with the best-available distance measurements or estimates. We present newly determined approximate white dwarf (WD) temperatures or upper limits and estimated accretion rates. The implications of our study for disk accretion physics and CV evolution are discussed. The average temperature of WDs in DNe below the period gap is ~18,000 K. For WDs in DNe above the period gap, the average WD temperature is ~26,000 K. There is a flux component, in addition to a WD photosphere, which contributes >60% of the flux in the FUV in 53% of the quiescent DNe in this study. We find that for 41% of the DNe in our sample, a WD photosphere provides >60% of the FUV flux. Accretion rates estimated from the FUV alone for the sample of DNe during quiescence ranged from 10-12 to 10-10 M☉ yr-1. The additional flux component is almost certainly not an optically thick accretion disk, since, according to the disk instability model, the disk should be optically thin and too cool during DN quiescence to be a significant FUV continuum emitter. Among the candidates for the second component of FUV light are the quiescent inner disk, a hot accretion belt at low WD latitudes centered on the equator, and hot rotating ring where the outer part of the boundary layer (the UV boundary layer) meets the inner disk and possibly heats it. The implications of our findings are discussed.