Gigantische Massen- und Volumenströme gasförmiger und flüssiger Medien werden in den Rohrleitungssystemen und Abfüllanlagen Deutschlands, Europas und weltweit bewegt, gemessen, zwischengehandelt und an den Endverbraucher verkauft. Angesichts der herausragenden wirtschaftlichen Bedeutung der Versorgung mit Gas, Wasser, Mineralöl, Wärme und neuerdings auch Kälte, und angesichts der politischen...

Gigantic mass and volume flows of gaseous and liquid media are transported and measured in the pipeline systems and filling plants of Germany, Europe, and worldwide, and sold to the ultimate consumer. In view of the outstanding economic importance of supplying gas, water, mineral oil, heat, and – lately - also refrigeration, and in view of the political discussions on energy efficiency,...

Die Ergebnisse der in 2006 durchgeführten Untersuchungen stellen die Grundlage für die Anforderungen hinsichtlich Explosionsschutz im technischen Arbeitsschutz bei bioethanolhaltigen Kraftstoffen (LV 47 / 2007) dar.

Für unterschiedliche Bioethanol/Ottokraftstoffgemische wurden folgende sicherheitstechnischen Kenngrößen bestimmt:

Untere Explosionsgrenze, obere Explosionsgrenze, oberer...

In preparation for an experiment for determining the half-lives of the isotopes U-235 and U-238, important for geochronology, and in cooperation with three additional institutes, the half-life of U-233 was determined with small uncertainties.

For determining the activity of electron-capture nuclides with the aid of liquid scintillation counting, an improved Monte-Carlo model was developed and tested with Cd-109 and I-125. The results show distinct improvements over earlier simplified analytical models.

In the case of dose measurements with ionisation chambers on electron accelerators it has not been customary up to now to determine volume recombination and initial recombination separately. By means of the corresponding measuring methods, relative dose deviations which can be traced back to ion losses can be reduced from a current value of approx. 0.2 % to less than 0.05 %.

Spectrometry and radiography on high-intensity lasers require detectors with the aid of which the neutrons emitted from the laser plasma can be detected a few nanoseconds after an extremely intensive γ-flash. For this measurement task, the time dependence of the light emission of different scintillators was investigated and optimized over 5 orders of the light intensity.

By simulating the ionization cluster generation in a nanometric target it is shown for light ions that the probabilities for the generation of ionization clusters with at least two ionization events can be directly used for the determination of the biological efficiency (RBW) required in hadron therapy.

The geometric properties of the small photon fields generated by a Co-60 irradiation device and a linear accelerator were investigated experimentally and with the aid of Monte Carlo calculations with respect to their suitability as reference radiation fields for dose measurements with the water calorimeter.

The response of a miniaturized dosemeter (developed in Italy) for clinical applications in the field of nanometry is at present being investigated at Department 6.6 with the aid of Monte Carlo simulation calculations. The first results show that the pulse height spectra calculated with conventional codes (MCNP and FLUKA) very strongly depend on the algorithms selected for the description of the...

For the calibration of the radioactive sources used for the therapy of prostate cancer - so-called seeds - PTB has developed a new primary standard measuring device which has been validated in the year under report on the basis of a comparison with calibrations of the National Institute of Standards and Technology (NIST). The deviations of the calibration values of NIST and PTB were smaller than...

The realization of the unit of the absorbed dose to water for interstitial brachytherapy, for example for the treatment of prostate carcinoma, has approached a little more. For low-energy photon radiation (up to approx. 40 keV) a new measurement method - based on an ionization chamber in a phantom - whose measurement volume can be varied has been developed.

At the accelerator facilities of PTB, nanometric spectra for monoenergetic He ions have for the first time been measured in the energy range between 0.1 MeV and 20 MeV and compared with Monte Carlo simulation calculations. Propane at a pressure of 1.2 mbar served as the measuring gas. For energies above approx. 0.4 MeV, the measured and calculated mean ionization cluster sizes are in good...

The measurand used in dosimetry for the therapy with X-radiation is the water absorbed dose.

For the simulation of radiation damages of the DNA, knowledge of all essential interaction processes between electrons and the components of the DNA is indispensable. As the interaction data so far known are still rather incomplete and in part even contradictory, the elastic differential electron cross sections of tetrahydrofuran (a main component of the DNA) were measured absolutely for primary...

For irradiations of extremity dosemeters, ISO recommends the use of a PMMA rod phantom 19 mm in diameter and 300 mm in length.

In many fields of physics, complete scattering cross section data are of great importance for the investigation of the electron transport in a medium. Examples are: transport phenomena in surface physics, plasma physics, dosimetry of ionizing radiation and atmospheric physics.

In Department 6.6, consistent cross section data for the elastic and inelastic scattering of electrons on argon have been...

For the first time, an international EUROMET measurement comparison was performed for beta radiation in the field of radiation protection. From Europe, the primary laboratories of Finland, France and Italy participated in addition to PTB which acted as pilot laboratory; from other continents, the institutes of Japan, Canada, Russia and the USA were involved. Most of the results agree within the...

A commercial, compact ESR spectrometer intended for use in industrial alanine dosimetry was investigated with respect to its possible use in radiation therapy dosimetry. If data analysis procedures developed at PTB are used, a relative measurement uncertainty of 1% (excluding the primary standard) at a dose of 10 Gy can be achieved. This indicates that such a spectrometer is indeed useable in...

The battery-operated data logger for simultaneous impulse counting, analogue signal measurement, serial data readout and data storage on one memory board is a new technical development.