Studies of lifetimes in an ion storage ring using laser technique

The laser-probing method for lifetime measurements of metastable levels, performed by applying the Fast Ion Beam Laser (FIBLAS) method to ions stored in a storage ring, has been developed by the Stockholm group. Recently, we have applied this method to lifetime measurements of close lying metastable levels. In this paper we discuss experimental studies of ions with complex structure and present the first experimentally obtained lifetimes of selected metastable levels in complex systems as Fe+, Eu+ and La+

Experimental INvestigation of radiative decay rates of metastable levels in Eu II

The radiative lifetimes of the metastable a 9DJ (J = 2-5) levels in Eu II have been measured by laser probing of a stored ion beam. The lifetimes of all four J levels are slightly above 1 s. A deviation from the expected energy dependence of the decay rates for electric quadrupole transitions is observed and discussed

Laser-probing measurements and calculations of lifetimes of the 5d D-2(3/2) and 5d D-2(5/2) metastable levels in BaII

peer reviewedThe two metastable levels 5d(2)D(3/2) and 5d(2) D-5/2 in Ba II both show extremely long lifetimes of the order of several tens of seconds each. This has been found both by experiments and by theoretical predictions. The small transition probabilities associated with these two levels make them interesting and challenging for theoreticians as well as for experimentalists. Several calculations and measurements of these two lifetimes have been made previously but discrepancies between the results are present. This article presents values of τ = 89.4 +/- 15.6 s for the D-2(3/2) level and τ = 32.0 +/- 4.6 s for the D-2(5/2) level measured in a beam-laser experiment performed at the ion storage ring CRYRING. These values are supported by our new calculations resulting in τ= 82.0 s for the D-2(3/2) level and τ= 31.6 s for the D-2(5/2) level

GMO sampling strategies in food and feed chains

The sampling step is relevant whenever it is necessary to evaluate an analyte in a lot. However, sampling is by far the most crucial step when the analyte is heterogeneously distributed in the lot, especially at low concentration, because high sampling uncertainty could invalidate the overall analytical testing. The economic and legal implications of such failure could greatly exceed the very high cost of accurate sampling. When there is a legal requirement that the analyte be analytically traced, low sampling reliability at any step of the production and distribution chains could cause the entire traceability system to fail. These considerations also apply to the legally - imposed GMO requirements, particularly those for labelling and traceability. Improper sampling can mislead both food producers and consumers about the GM content in products. In addition, if GMO tests fail to detect an unauthorised GM crop, those unauthorised crops could pose potential risks to human and animal health. Failure of traceability could result in collapse of transgenic and conventional/organic co - existence in the fi eld, with subsequent environmental and economic consequences. A sampling plan should be reliable, cost - effective and feasible in the real life. ‘ Fit - for - purpose ’ sampling plans should be studied and applied, given the wide variety of field situations and ultimate goals. In addition, the uncertainty level of the ‘ overall analytical chain ’ is relevant in many respects, such as making decisions about the best procedures to put in place. Uncertainty in GMO sampling is high, therefore statistical studies should be performed to evaluate sampling uncertainty or at least generate insight into how to make responsible decisions on the most appropriate sampling plan to adopt at each step of the food and feed chain. Prior to the European research project Co - Extra, valuable and indispensible research had been conducted on topics such as the distribution of GMOs in a lot and the implementation of reliable software tools to reveal the most suitable sample size for GMO detection. Research conducted within the Co - Extra project fi lled in relevant theoretical gaps related to the assessment of control plans. All of this research represents a basis for selecting appropriate sampling plans that are best adapted to the operational conditions.JRC.I.3-Molecular Biology and Genomic