Arthur Heiss - Academia.edu (original) (raw)

Papers by Arthur Heiss

A method and apparatus for inspecting the shelf life of liquid foodstuffs by means of electron spin resonance

Cryocast-system mit flexibler schnittstelle und fernkühlung

Ultra-Low Vibration Cryogen-Free Cryostat for an Electron Paramagnetic Resonance System

Method and Device for Analysing the Stability of Fluid Foodstuffs by Means of Electron Spin Resonance

Cryogen-Free Cooling System for Electron Paramagnetic Resonance Spectrometer

Method and apparatus for investigating the imperishability of liquid foodstuffs by means of electron spin resonance

Radiation Physics and Chemistry, 2000

High stability of the radiation-induced radicals in alanine and the high reproducibility of alani... more High stability of the radiation-induced radicals in alanine and the high reproducibility of alanine response to radiation make it possible to determine radiation doses accurately with Electron Paramagnetic Resonance (EPR) spectral analysis. Small uncontrollable variations of the EPR spectrometer sensitivity, however, can signi®cantly deteriorate the accuracy of the method. The errors due to these variations can be eliminated or markedly decreased if an adjacent reference sample (such as a synthetic ruby crystal) is permanently present in the cavity, and if ratios of the alanine and ruby signal amplitudes are used throughout the dosimetric session instead of the absolute alanine amplitudes. This paper addresses methodological aspects of using such adjacent reference samples in alanine dosimetry and provides illustrations of the usefulness of this technique.

Radiation Physics and Chemistry, 2002

The National Institute of Standards and Technology (NIST) is expanding into a new frontier in the... more The National Institute of Standards and Technology (NIST) is expanding into a new frontier in the delivery of measurement services. The Internet will be employed to provide industry with electronic traceability to national standards. This is a radical departure from the traditional modes of traceability and presents many new challenges. The traditional mail-based calibration service relies on sending artifacts to the user, who then mails them back to NIST for evaluation. The new service will deliver calibration results to the industry customer on-demand, in real-time, at a lower cost. The calibration results can be incorporated rapidly into the production process to ensure the highest quality manufacturing. The service would provide the U.S. radiation processing industry with a direct link to the NIST calibration facilities and its expertise, and provide an interactive feedback process between industrial processing and the national measurement standard. Moreover, an Internet calibration system should contribute to the removal of measurement-related trade barriers.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007

International standards and guidelines for calibrating high-dose dosimetry systems to be used in ... more International standards and guidelines for calibrating high-dose dosimetry systems to be used in industrial radiation processing recommend that dose-rate effects on dosimeters be evaluated under conditions of use. This is important when the irradiation relies on highcurrent electron accelerators, which usually provide very high dose-rates. However, most dosimeter calibration facilities use low-intensity gamma radiation or low-current electron accelerators, which deliver comparatively low dose-rates. Because of issues of thermal conductivity and response, portable calorimeters cannot be practically used with high-current accelerators, where product conveyor speeds under an electron beam can exceed several meters per second and the calorimeter is not suitable for use with product handling systems. As an alternative, Monte Carlo calculations can give theoretical estimates of the absorbed dose in materials with flat or complex configurations such that the results are independent of dose-rate. Monte Carlo results can then be compared to experimental dose determinations to see whether dose-rate effects in the dosimeters are significant. A Monte Carlo code has been used in this study to calculate the absorbed doses in alanine film dosimeters supported by flat sheets of plywood irradiated with electrons using incident energies extending from 1.0 MeV to 10 MeV with beam currents up to 30 mA. The same process conditions have been used for dose determinations with high-current electron beams using low dose-rate gamma calibrated alanine film dosimeters. The close agreement between these calculations and the dosimeter determinations indicates that the response of this type of dosimeter system is independent of the dose-rate, and provides assurance that Monte Carlo calculations can yield results with sufficient accuracy for many industrial applications.

Individual Biodosimetry at the Natural Radiation Background Level

Health Physics, 2001

The present note describes new advancements to a valued tool in retrospective biodosimetry that l... more The present note describes new advancements to a valued tool in retrospective biodosimetry that lower the threshold of detection of radiation dose to 29 mGy. The advanced method is based on the electron paramagnetic resonance measurements of stable radiation-induced radicals in tooth enamel. Earlier this method had been used only for reconstruction of high radiation doses obtained accidentally. New opportunity of reconstruction of doses lower than 100 mGy opens a new realm of possibilities for assessing the health effects of ionizing radiation at the natural radiation background level.

Cryogen-Free Cooling System for Electron Paramagnetic Resonance System

Radiation Physics and …, 2004

The alanine dosimetry system is now preferred by all primary and secondary calibration laboratori... more The alanine dosimetry system is now preferred by all primary and secondary calibration laboratories for their high-dose ionizing radiation calibration services. Alanine dosimeters in the form of cylindrical pellets have been available in commercial quantities for several years. Despite their high ...