The cold neutron three-axis spectrometer IN12 at the ILL

The cold neutron three-axis spectrometer IN12 is operated by the Juelich Centre for Neutron Science (JCNS) in collaboration with the CEA-Grenoble as a CRG-B instrument at the Institut Laue-Langevin (ILL) in Grenoble, France.With an upgrade accomplished in 2012 the instrument has been relocated to an end position of a new guide and the whole primary spectrometer has been upgraded.With a virtual source concept and a new double focussing PG monochromator IN12 has gained a factor of 10 in flux at the sample position with a peak flux of about 108 n/sec/cm2 around ki = 2 Å−1. An extended wavelength range far into the warmish region (max. ki ≈ 5.1 Å−1) is now available. A velocity selector in the guide ensures a clean beam, and a vertical guide changing system with a transmission polarizing cavity guarantees an easy-to-use polarization set-up.IN12 is one of the rare spectrometers that can use polarisation analysis in combination with high magnetic fields.The multi-analyser multi-detector option IN12-UFO is interchangeable with the standard secondary spectrometer and allows to program simultaneous scans in Q-ω space. We plan the installation of a second monochromator using perfectly bent Si(111) crystals. For lowest accessible wavevector range and energy transfer, it will provide a cleaner signal-to-noise ratio, clean tails of the elastic line and better energy resolution.Its sharper focussing is advantageous when using high field magnets

The upgrade of the cold neutron three-axis spectrometer IN12 at the ILL

After nearly 40 years of successful operation the cold three-axis spectrometer IN12 at the Institut Laue-Langevin, Grenoble, France, has been relocated to a new position and the primary spectrometer has been upgraded. Latest modern optical components are employed. A new guide in combination with a virtual source concept and a double focusing monochromator guarantee highest flux. With its high unpolarized and polarized neutron flux IN12 allows for demanding experiments. A velocity selector in the guide ensures a clean beam and a very low background. A gain in flux of about an order of magnitude at the sample position has been achieved compared to the previous instrument and IN12׳s wavelength range now extends far into the warmish region

Eccentric gaze direction in patients with central field loss

Item does not contain fulltextPURPOSE.: This study describes the binocular eccentric gaze direction (EGD) of 434 patients with binocular central field loss and presents a comparison with other studies on eccentric gaze behavior. METHODS.: We reviewed the records of 434 patients with bilateral central scotomas. Eligible patients had not received eccentric viewing training and demonstrated a spontaneously developed eccentric gaze behavior. Data were collected on monocular and binocular EGD, visual acuity, and underlying ocular pathology. Findings concerning the EGD were compared with other studies that evaluated gaze behavior in patients with central field loss. RESULTS.: In the group of 434 patients, age-related macular disease was the most frequent pathology (77%). The majority of these patients demonstrated a binocular EGD (bEGD) to the right (50%). In 25% of the patients, a superior bEGD was found. Less often, a bEGD to the left (14%) and to inferior (11%) were encountered. Review of the literature indicates that the majority of patients developed a monocular EGD in the superior direction. CONCLUSIONS.: This is a study on bEGD behavior in a large population of patients with bilateral central scotomas. The bEGD was guided by the gaze of the better-seeing eye. The preference for a bEGD to the right differs from findings of previous studies. Review of the literature suggests that not only the ocular pathology but also the method of investigation is most likely to influence the observed EGD. Most studies evaluated the location of the preferred retinal locus using a monocular technique; this may not reflect an individual's actual binocular behavior as it relates to activities of daily living