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The Energy Recovery Linac Prototype (ERLP) is currently being constructed at Daresbury Laboratory primarily to gain understanding of accelerator physics issues for the proposed Fourth Generation Light Source (4GLS). The radiation from two sources on ERLP, THz radiation from the last bending magnet in the bunch compressor, and the IR FEL radiation, will be used for machine diagnostics. Radiation from these sources will be transported into a ‘diagnostic room’ for power and spectral analysis. The THz radiation will also be used for end user experiments. The layout of the optical transport and detection systems will be presented. Results will also be given for the predicted performance of the optical beamline obtained using wavefront propagation. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

4GLS is a proposed 4th generation light source at Daresbury Laboratory, based on an ERL design, and including within the ERL a cavity based VUV FEL and XUV amplifier FEL. In the conceptual design electron bunches from a superconducting linac are bent through 180 degrees into two possible return paths, one through the XUV FEL and one through a branch containing insertion devices and the cavity FEL. A major design issue affecting the whole layout of the source is the effect of wakefields, in particular coherent synchrotron radiation (CSR), in the bending arcs. This causes significant energy loss and bunch lengthening, and may also cause micro-bunching, and is particularly detrimental for the short, high density bunches required for the XUV FEL. Modelling of the CSR in the bending arcs has been performed using the electron tracking code ELEGANT of Borland, which contains a 1D model of CSR. This model will be cross-checked using Trafic4 of Dohlus et al which implements a full 3-D formalism. Proposals for the design of the 4GLS arcs are presented, based on these results. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

A new extreme flux vacuum ultraviolet bending magnet beamline (CD12) has been commission at the SRS, Daresbury. The beamline has met all of its designed performance parameters and these are detailed. The clear advantages of SRCD over CD undertaken on conventional instruments are discussed and examples of its capabilities in terms of measurement precision and enhanced signal-to-noise for both steady-state CD and time-resolved CD are given. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

Photon beam diagnostics for vacuum-ultraviolet free electron lasers (VUV FEL) are critical to monitoring and understanding their performance characteristics. Due to the shot-to-shot fluctuations inherent in FELs based on the self amplified spontaneous emission (SASE) process, it is mandatory to use pulse-resolved diagnostics. We have designed a spectrograph based on a variable-line-spacing (VLS) plane grating and a phosphor/CCD to monitor single shot spectra of the free electron laser at DESY. The basic concept is to allow most of the beam to be reflected towards an experimental station while the first order light is dispersed and focused by the VLS grating onto the CCD. The spectrograph will cover the wavelength range 6.4–60 nm with the CCD accepting a bandwidth of ∼10%. The grazing angle of incidence on the grating is 2°, the central line density is 1200 l/mm, and the distance grating-CCD is approximately 2 m. The linear variation of the grating line spacing combined with positioning the detector at the focal curve, allows zeroing the defocus in the full spectrograph wavelength range. The correction of higher order grating aberrations yields a theoretical resolving power greater than 20000 over the full length of the 20 mm CCD when the CCD is positioned tangent to the focal plane. Based on power considerations, a shallow blazed grating is the preferred profile. Efficiency calculations over the spectrograph range show that with a carbon coating the absolute efficiency for zeroth order is higher than 0.85 and the first order efficiency varies between 0.5% and 8%. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

The Sudbury Neutrino Observatory (SNO) is a 1,000 tonne heavy water Cerenkov-based neutrino detector situated 2,000 meters underground in INCO's Creighton Mine near Sudbury, Ontario, Canada. For the neutrinos from [sup 8]B decay in the Sun SNO observes the Charged Current neutrino reaction sensitive only to electron neutrinos and others (Neutral Current and Elastic Scattering) sensitive to all active neutrino types and thereby can search for direct evidence of neutrino flavor change. Using these reactions and assuming the standard [sup 8]B shape, the ν[sub e] component of the [sup 8]B solar flux is φ[sub e] = 1.76[sup +0.05, sub -0.05](stat.)[sup +0.09, sub -0.09] (syst.) × 10[sup 6] cm[sup -2]s[sup -1] for a kinetic energy threshold of 5 MeV. The non-ν[sub e] component is φ[sub μτ] = 3.41[sup +0.45, sub -0.45](stat.)[sup +0.48, sub 0.45] (syst.) × 10[sup 6] cm[sup -2]s[sup -l], 5.3σ greater than zero, providing strong evidence for solar ν[sub e] flavor transformation. The total flux measured with the NC reaction is φ[sub NC] = 5.09[sup +0.44, sub -0.43](stat.)[sup +0.46, sub -0.43] (syst.) × 10[sup 6] cm[sup -2]s[sup -1] consistent with solar models. For charged current events, assuming an undistorted [sup 8]B spectrum, the night minus day rate is 14.0% ± 6.3%[sup +1.5. sub -1.4]% of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the ν[sub e] asymmetry is found to be 7.0% ± 4.9%[sup +1.3, sub -1.2]%. A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the Large Mixing Angle (LMA) solution. [ABSTRACT FROM AUTHOR]