List-mode data acquisition based on digital electronics - State-of-the-art report

This report deals with digital radiation detection systems employing list-mode data collection, which improves data analysis capabilities. Future data acquisition systems shall also ultimately enable the movement of detection data from first responders electronically to analysis centres rather than the costly and time consuming process of moving experts and/or samples. This new technology is especially useful in crisis events, when time and resources are sparse and increased analysis capacity is required. In order to utilise the opportunities opened by these new technologies, the systems have to be interoperable, so that the data from each type of detector can easily be analysed by different analysis centres. Successful interoperability of the systems requires that European and/or international standards are devised for the digitised data format. The basis of such a format is a list of registered events detailing an estimate of the energy of the detected radiation, along with an accurate time-stamp for recorded events (and optionally other parameters describing each event).JRC.G.5-Security technology assessmen

European Reference Network for Critical Infrastructure Protection: - Novel Detection Technologies for Nuclear Security

Radiation detectors are used in nuclear security to detect nuclear and other radioactive materials out of regulatory control. In nuclear security, both the operational environment and detector technologies are constantly evolving. This document provides an overview on recent development on radiation detection technologies that are likely to have an impact on nuclear security in the near future. The four main topics covered are: detectors for gamma-ray spectrometry, neutron detectors, data acquisition and source localisation. This document will be published together with another report that concentrates on the impact of novel detection technologies from operational point of view. Therefore, the focus of this document is on technical aspects of the technologies.JRC.E.2-Technology Innovation in Securit

Decay of [Formula Presented] to [Formula Presented]

The decay of on-line mass-separated [Formula Presented] has been studied by [Formula Presented] spectroscopy. A definite odd parity and a probable [Formula Presented] are deduced for the high-spin [Formula Presented]-decaying level. The 1116 keV and 1392 keV levels in the [Formula Presented] daughter nucleus are candidates for the bottom of the [Formula Presented] band. There is no support for a previously reported very-low-lying [Formula Presented] level at 871 keV. A [Formula Presented] band built on the new level at 1639 keV is proposed. The lowest-lying two-quasiparticle levels in [Formula Presented] are calculated in the framework of the quantum Monte Carlo pairing model using deformed shell model states. The lowest configurations are associated with an oblate minimum of the potential energy.</p

Critical parameters and performance tests for the evaluation of digital data acquisition hardware

Recent developments of digital data acquisition systems allow real-time pre-processing of detector signals at a high count rate. These so-called pulse processing digitizers are powerful and versatile instruments offering techniques which are important for nuclear security, critical infrastructure protection, nuclear physics and radiation metrology. Certain aspects of digital data acquisition affect the performance of the total system in a critical way and therefore require special attention. This report presents a short introduction to digital data acquisition, followed by a discussion of the critical parameters which affect the performance in the lab and in the field. For some of the parameters, tests are proposed to assess the performance of digital data acquisition systems. Good practices are offered to guide the selection and evaluation of digital data acquisition systems. More general performance criteria which are not specifically related to digital data acquisition systems are discussed separately.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Studies of release properties of ISOLDE targets

Off-line release rates of Be, Mg, S, Mn and Kr from refractory materials were studied. Mn yields were determined from a ZrO2 target and Kr yields from a SrO and ZrO2 targets. A Monte Carlo code to optimize ISOLDE targets was introduced

A sextupole ion beam guide to improve the efficiency and beam quality at IGISOL

The laser ion source project at the IGISOL facility, Jyvaskyla, has motivated the development and construction of an rf sextupole ion beam guide (SPIG) to replace the original skimmer electrode. The SPIG has been tested both off-line and on-line in proton-induced fission, light-ion and heavy-ion induced fusion-evaporation reactions and, in each case, has been directly compared to the skimmer system. For both fission and light-ion induced fusion, the SPIG has improved the mass-separated ion yields by a factor of typically 4 to 8. Correspondingly, the transmission efficiency of both systems has been studied in simulations with and without space charge effects. The transport capacity of the SPIG has been experimentally determined to be 10^12 ions/s before space charge effects start to take effect. A direct comparison with the simulation has been made using data obtained via light-ion fusion evaporation. Both experiment and simulation show an encouraging agreement as a function of current extracted from the ion guide.Comment: Latex formatted, submitted to NIM B, 17 pages with 22 .eps figure

Off-line studies of the laser ionization of yttrium at the IGISOL facility

A laser ion source is under development at the IGISOL facility, Jyvaskyla, in order to address deficiencies in the ion guide technique. The key elements of interest are those of a refractory nature, whose isotopes and isomers are widely studied using both laser spectroscopic and high precision mass measurement techniques. Yttrium has been the first element of choice for the new laser ion source. In this work we present a new coupled dye-Ti:Sapphire laser scheme and give a detailed discussion of the results obtained from laser ionization of yttrium atoms produced in an ion guide via joule heating of a filament. The importance of not only gas purity, but indeed the baseline vacuum pressure in the environment outside the ion guide is discussed in light of the fast gas phase chemistry seen in the yttrium system. A single laser shot model is introduced and is compared to the experimental data in order to extract the level of impurities within the gas cell.Comment: 18 pages submitted to NIM

Ground-state spin of 59^{59}Mn

Beta decay of $^{59}$Mn has been studied at PSB-ISOLDE, CERN. The intense and pure Mn beam was produced using the Resonance Ionization Laser Ion Source (RILIS). Based on the measured $\beta$-decay rates the ground-state spin and parity are proposed to be $J^{\pi}$ = 5/2$^{-}$. This result is consistent with the systematic trend of the odd-A Mn nuclei and extends the systematics one step further towards the neutron drip line

Robotic equipment carrying RN detectors: requirements and capabilities for testing

77 pags., 32 figs., 5 tabs.-- ERNCIP Radiological and Nuclear Threats to Critical Infrastructure Thematic Group . -- This publication is a Technical report by the Joint Research Centre (JRC) . -- JRC128728 . -- EUR 31044 ENThe research leading to these results has received funding from the European Union as part of the European Reference Network for Critical Infrastructure Protection (ERNCIP) projec

The beta-decay of 22Al

In an experiment performed at the LISE3 facility of GANIL, we studied the decay of 22Al produced by the fragmentation of a 36Ar primary beam. A beta-decay half-life of 91.1 +- 0.5 ms was measured. The beta-delayed one- and two-proton emission as well as beta-alpha and beta-delayed gamma decays were measured and allowed us to establish a partial decay scheme for this nucleus. New levels were determined in the daughter nucleus 22Mg. The comparison with model calculations strongly favours a spin-parity of 4+ for the ground state of 22Al