25 research outputs found
Instrument intercomparison in the high-energy mixed field at the CERN-EU reference field (CERF) facility
This paper discusses an intercomparison campaign performed in the mixed radiation field at the CERN-EU (CERF) reference field facility. Various instruments were employed: conventional and extended-range rem counters including a novel instrument called LUPIN, a bubble detector using an active counting system (ABC 1260) and two tissue-equivalent proportional counters (TEPCs). The results show that the extended range instruments agree well within their uncertainties and within 1σ with the H*(10) FLUKA value. The conventional rem counters are in good agreement within their uncertainties and underestimate H*(10) as measured by the extended range instruments and as predicted by FLUKA. The TEPCs slightly overestimate the FLUKA value but they are anyhow consistent with it when taking the comparatively large total uncertainties into account, and indicate that the non-neutron part of the stray field accounts for ∼30 % of the total H*(10
Comparison of Cosmic Radiation Detectors in the Radiation Field at Aviation Altitudes
An assessment of the exposure of aircrew and passengers to the complex radiation field at
aviation altitudes has been a challenging task and a legal obligation in the European Union for
many years. The response of several radiation measuring instruments to this radiation field
was investigated by different European research groups within the framework of the
CONCORD campaign (COmparisoN of COsmic Radiation Detectors) in the Radiation Field
at Aviation Altitudes. We measured dose rates at four positions in the atmosphere in European
airspace, two altitudes at two locations respectively, under quiet space weather conditions
during joint measuring flights with the twin-jet research aircraft Dassault Falcon 20E operated
by the DLR flight facility Oberpfaffenhofen. The results show a very good agreement
between the readings of the instruments of the different research groups as well as for the
comparison of the corresponding average values with PANDOCA model calculations
Radiation protection of aircraft crew: publicly available database of measurements with the silicon spectrometer Liulin on board aircraft
Annual effective doses of aircrew from occupational exposure are typically up to 6 mSv, depending on the number of flight hours, route locations, and solar activity. In many cases, these doses exceed the limit for public exposure to ionizing radiation and thus ICRP recommended their monitoring. Radiation fields at aircraftaltitudes are complex and difficult to measure experimentally. For this reason, the doses are estimated via computer codes that take into account flight parameters like aircraft location and altitude, and solar activity. It is generally accepted, that these calculations should be periodically verified by measurements. Precisemeasurements with tissue equivalent proportional counters are typically short-term only as these detectors are bulky and have only limited battery life. For long-term measurements, which are needed to cover the whole 11-year solar cycle, the silicon spectrometer Liulin is better suited. Liulin is an active dosimeter which records energy deposition events occurring in the semiconductor unit, and – if appropriately calibrated – it estimates neutron and non-neutron component of the ambient dose equivalent. This paper presents a database of long-term measurements performed on board aircraft with the Liulin detector. The measurements started in 2001. For one run, Liulin was placed in the cabin of a Czech Airlines aircraft for approximately 50 days. So far 28 runs were performed, i. e. about 3 500 flights and almost 20 000 flight hours. Flights were flown from Prague to destinations with vertical cut-off rigidities ranging from 1 GV to 17 GV. The most frequent were transatlantic flights from Prague to New York and to Canada. The database comprises more than 105 records where each record contains information on: energy deposition spectra, absorbed dose rates and dose equivalent rates measured with Liulin, date and time, geographic coordinates and altitude. The data are available on the Internet and can be used for instance for verification of computational programs routinely used for estimation of aircrew exposure to cosmic radiation.14th International Congress of Radiation Researc
Publicly available database of measurements with the silicon spectrometer Liulin onboard aircraft
Aircrew members are exposed to ionizing radiation due to their work onboard aircraft. ICRP recommended the monitoring of their effective doses because they regularly exceed the limit of 1 mSv per year for the public exposure. The effective doses are routinely calculated by computer codes that take into account flight parameters like altitude, geographic position, and solar activity. This approach was preferred against personal dosimeters method because the effective dose cannot be evaluated experimentally. However, it is generally accepted, that these calculations should be periodically verified by measurements of H*(10) which is frequently used as a surrogate for effective dose. This report refers about the database (available online http://hroch.ujf.cas.cz/ similar to aircraft/) of long-term measurements with the silicon spectrometer Liulin onboard aircraft. The measurements have been performed since March 2001; so up to date, the database covers a period of 11-years (with a few interruptions) which is usually the duration of the whole solar cycle. The database comprises more than 10(5) individual records of energy deposition spectra, absorbed dose rates, and ambient dose equivalent rates. Each record contains also the information on all flight parameters needed for calculation of dosimetric quantities by the computer codes, and thus the database represent an useful tool for verification of the routine dosimetry of aircraft crews. (C) 2013 Elsevier Ltd. All rights reserved
CONCORD: comparison of cosmic radiation detectors in the radiation field at aviation altitudes
Space weather can strongly affect the complex radiation field at aviation altitudes. The assessment of the corresponding radiation
exposure of aircrew and passengers has been a challenging task as well as a legal obligation in the European Union for many
years. The response of several radiation measuring instruments operated by different European research groups during joint measuring
flights was investigated in the framework of the CONCORD (COmparisoN of COsmic Radiation Detectors) campaign in
the radiation field at aviation altitudes. This cooperation offered the opportunity to measure under the same space weather conditions
and contributed to an independent quality control among the participating groups. The CONCORD flight campaign was
performed with the twin-jet research aircraft Dassault Falcon 20E operated by the flight facility Oberpfaffenhofen of the German
Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt, DLR). Dose rates were measured at four positions in the atmosphere
in European airspace for about one hour at each position in order to obtain acceptable counting statistics. The analysis of
the space weather situation during the measuring flights demonstrates that short-term solar activity did not affect the results which
show a very good agreement between the readings of the instruments of the different institutes