Accelerator performance analysis of the Fermilab Muon Campus

Fermilab is dedicated to hosting world-class experiments in search of new physics that will operate in the coming years. The Muon g-2 Experiment is one such experiment that will determine with unprecedented precision the muon anomalous magnetic moment, which offers an important test of the Standard Model. We describe in this study the accelerator facility that will deliver a muon beam to this experiment. We first present the lattice design that allows for efficient capture, transport, and delivery of polarized muon beams. We then numerically examine its performance by simulating pion production in the target, muon collection by the downstream beam line optics, as well as transport of muon polarization. We finally establish the conditions required for the safe removal of unwanted secondary particles that minimizes contamination of the final beam.Comment: 10 p

FUV and X-ray Observations of the Reverse Shock in the SMC SNR 1E 0102.2-7219

We present FUSE and XMM-Newton data for the reverse shock of the O-rich SNR 1E0102.2-7219 in the SMC. The FUSE observations cover three regions with significantly different optical [O III] intensities, all associated with the relatively bright part of the X-ray ring. Emission lines of O VI 1032, 1038 are clearly detected in the FUSE spectra. By combining this O VI doublet emission with the O VII triplet and O VIII Lyalpha fluxes from the XMM-Newton spectra and assuming a non-equilibrium ionization model with a single ionization timescale for the spectra, we are able to find a narrow range of temperatures and ionization timescales that are consistent with the respective line ratios. However, if we assume a plane-parallel shock model with a distribution of ionization timescales, the O VI emission appears to be inconsistent with O VII and O VIII in X-rays. We also analyze the total XMM-Newton EPIC-MOS 1/2 spectra for the three regions. The X-ray spectra are dominated by strong emission lines of O, Ne, and Mg, however, we detect an emission component that accounts for 14 - 25% of the flux and can be attributed to shocked ISM. We find that there is no consistent set of values for the temperature and ionization timescale which can explain the observed line ratios for O, Ne, and Mg. This would be consistent with a structured distribution of the ejecta as the O, Ne, Mg would have interacted with the reverse shock at different times.Comment: 28 pages, 5 figues, Fig. 1 as JPEG. To be published in ApJ (01 May 2006, v. 642, 1 issue

Spitzer Spectral Mapping of Supernova Remnant Cassiopeia A

We present the global distribution of fine structure infrared line emission in the Cassiopeia A supernova remnant using data from the Spitzer Space Telescope's Infrared Spectrograph. We identify emission from ejecta materials in the interior, prior to their encounter with the reverse shock, as well as from the post-shock bright ring. The global electron density increases by >~100 at the shock to ~10^4 cm^-3, providing evidence for strong radiative cooling. There is also a dramatic change in ionization state at the shock, with the fading of emission from low ionization interior species like [SiII], giving way to [SIV] and, at even further distances, high-energy X-rays from hydrogenic silicon. Two compact, crescent-shaped clumps with highly enhanced neon abundance are arranged symmetrically around the central neutron star. These neon crescents are very closely aligned with the "kick" direction of the compact object from the remnant's expansion center, tracing a new axis of explosion asymmetry. They indicate that much of the apparent macroscopic elemental mixing may arise from different compositional layers of ejecta now passing through the reverse shock along different directions.Comment: 9 pages, 8 figures, accepted by Ap

Recovery of the Historical SN1957D in X-rays with Chandra

SN1957D, located in one of the spiral arms of M83, is one of the small number of extragalactic supernovae that has remained detectable at radio and optical wavelengths during the decades after its explosion. Here we report the first detection of SN1957D in X-rays, as part of a 729 ks observation of M83 with \chandra. The X-ray luminosity (0.3 - 8 keV) is 1.7 (+2.4,-0.3) 10**37 ergs/s. The spectrum is hard and highly self-absorbed compared to most sources in M83 and to other young supernova remnants, suggesting that the system is dominated at X-ray wavelengths by an energetic pulsar and its pulsar wind nebula. The high column density may be due to absorption within the SN ejecta. HST WFC3 images resolve the supernova remnant from the surrounding emission and the local star field. Photometry of stars around SN1957D, using WFC3 images, indicates an age of less than 10**7 years and a main sequence turnoff mass more than 17 solar masses. New spectra obtained with Gemini-South show that the optical spectrum continues to be dominated by broad [O III] emission lines, the signature of fast-moving SN ejecta. The width of the broad lines has remained about 2700 km/s (FWHM). The [O III] flux dropped precipitously between 1989 and 1991, but continued monitoring shows the flux has been almost constant since. In contrast, radio observations over the period 1990-2011 show a decline rate inf the flux proportional to t**-4, far steeper than the rate observed earlier, suggesting that the primary shock has overrun the edge of a pre-SN wind.Comment: 28 pages, including 3 tables and 7 figures, accepted for publication in Ap

Results of the Cooperative Uniform Soybean Tests, 1947 Part I. North Central States

United States Department of Agriculture, Agricultural Research Administration; Bureau of Plant Industry, Soils, and Agricultural Engineering, Division of Forage Crops and Diseases Cooperating with State Agricultural Experiment Station