Calibration of the ISOLDE acceleration voltage using a high-precision voltage divider and applying collinear fast beam laser spectroscopy

A high-voltage divider with accuracy at the ppm level and collinear laser spectroscopy were used to calibrate the highvoltage installation at the radioactive ion beam facility ISOLDE at CERN. The accurate knowledge of this voltage is particularly important for collinear laser spectroscopy measurements. Beam velocity measurements using frequencycomb based collinear laser spectroscopy agree with the new calibration. Applying this, one obtains consistent results for isotope shifts of stable magnesium isotopes measured using collinear spectroscopy and laser spectroscopy on laser-cooled ions in a trap. The long-term stability and the transient behavior during recovery from a voltage dropout were investigated for the different power supplies currently applied at ISOLDE.Comment: 13 pages, 6 figure

Multiphysics simulations for the optimisation of CMOS processes for high precision optical measurement applications: Congress report

During the last years complementary metal oxide semiconductor (CMOS) technologies found widespread use in the fabrication of optical sensors and imagers. However, during the development of CMOS photodiodes for special high precision applications like spectroscopy various aspects have to be considered that are negligible for photodiodes employed in common imaging applications. Using two approaches, each combining optical simulations of the impinging radiation with electrical simulations of the generated charge carriers, an improved photodiode design for spectroscopy applications is studied in terms of spectral sensitivity as well as optical and electrical crosstalk. It will be demonstrated how the proper combination of these two approaches leads to an efficient development of the improved photodiode design prior to the first fabrication activities, which is important due to the huge effort, both in cost and time, that is involved in CMOS fabrication

Neue CMOS-Bildsensoren erweitern Einsatzmöglichkeiten

Eine Silizium-Nitrid-Schutzschicht, die transparent für UV-Strahlung ist, erweitert die Einsatzmöglichkeiten von CMOS-Bildsensoren. So können sie beispielsweise in der Bioanalytik aber auch bei der Kontrolle von Autolacken eingesetzt werden