Advancements in accuracy of the alanine dosimetry system. Part 2. The influence of the irradiation temperature

Nagy, Vitaly; Puhl, James M.; Desrosiers, Marc F.

doi:10.1016/s0969-806x(99)00339-4

Cited by 62 publications

(38 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By contrast, calibration with alanine against the national standard sources requires only two corrections: one for 60 Co decay with a precisely known half-life of 1925.23 days (Nagy, Puhl, et al 2000) and another for differences between the mass energy absorption coefficients for water and soft tissue, which is small (<1%) and reasonably well-known (Woods, et al 2004). …”

Section: Discussionmentioning

confidence: 99%

“…Prior to use, the pellets were stored in a desiccator over phosphorus pentoxide, which provided 0% relative humidity . The pellets were conditioned to the humidity of the ambient environment before use (Nagy, Puhl, et al 2000) and were irradiated in the phantoms in plastic vials purchased from NIST (figure 4). The vial height was approximately 30 mm; the outer diameter was 12 mm, while the inner diameter allowed 0.2 mm of space for the 4.9 mm diameter of the pellets (Nagy and Desrosiers, 1996).…”

Section: Dosimetrymentioning

confidence: 99%

“…An alanine response temperature coefficient of 0.14% per degrees Celsius (Nagy, Puhl, and Desrosiers 2000), provided by the software by default, was used to correct for small differences in the temperature of irradiation at AFRRI and NIST.…”

Section: Dosimetrymentioning

confidence: 99%

See 2 more Smart Citations

Alanine Dosimetry Accurately Determines Radiation Dose in Nonhuman Primates

Nagy¹,

Parra²,

Shoemaker³

et al. 2007

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Section: Dosimetrymentioning

confidence: 99%

See 1 more Smart Citation

Alanine Dosimetry Accurately Determines Radiation Dose in Nonhuman Primates

Nagy¹,

Parra²,

Shoemaker³

et al. 2007

View full text Add to dashboard Cite

“…All the dosimeters returned from the NPP were stored under stable conditions in darkness (temperature: 21~26ºC, relative humidity: 16~ 22%). For determination of the absorbed dose of alanine dosimeters, measurements were performed at least eight times on a daily basis after two or three weeks and data was corrected by the factor of the dosimeter mass and the irradiation temperature in the NPP (0.14%/K, 25ºC) [12]. To accurately measure the peak to peak ratio ("x/y ratio" or No 7 over No 8 ratio in Fig.…”

Section: Dosimeter Installation and Measurementmentioning

confidence: 99%

Application of Alanine/Esr Spectrum Shape Change in Gamma Dosimetry

Choi¹,

Kim²,

Lee³

et al. 2010

Nuclear Engineering and Technology

View full text Add to dashboard Cite

Temperature and radiation are two of the major environmental elements exerting aging effects on the incontainment instrumentation and control cables connected to major components. The effect of radiation on cable material is related to the total absorbed dose, which is mainly dependent on gamma rays [1]. For validity of radiation measurement, at least two operation cycles are required for the installation period. Generally used personal dosimeters are not appropriate for this application due to their rapid signal fading feature and relatively poor linearity at a range of high dose. Alanine-electron spin resonance (ESR) dosimetry material, meanwhile, has been proved to be suitable for long term measurement on the basis of the following factors: small signal dependency on temperature ( 0.2%/K), limited signal fading ( 1%/year), and low influence of humidity, which can be easily overcome by hermetic sealing of capsules [2]. Based on the aforementioned advantages as a long term dosimetry material, in the present study dozens of pellet type alanine dosimeters were installed at selected positions in a nuclear power plant (NPP) for two operation cycles. ESR dosimety is known as a retrospective dosimetry method that can be applied in an emergency after an accident and is accepted as a secondary standard and transfer dosimeter for the comparison of dose quantity between laboratories [3][4][5]. Recently, it was found that the peaks of spectra are mainly due to three kinds of radicals induced by radiation [6][7][8].The central resonance peak amplitude of main peaks is used to estimate radiation dose quantity. The weak "satellite line" beside the central resonance peak has been interpreted as the combined effects of "spin flip" of neighboring hydrogen protons of the methyl group of the paramagnetic center and a R2 radical [9][10][11]. The ratio of the "satellite line and main central resonance peak" is frequently expressed as the "x/y ratio". A decrease of this ratio has been explained by less saturation resistance of the main peak amplitude, which is caused by a decrease of the spin-lattice relaxation time T1. Crystallographic defects and plastic deformation in the structure of the alanine lattice by thermal shock of high linear energy transfer (LET) radiation have been reported as the most likely causes of relaxation time change. The "x/y ratio" irradiated with mixed radiation, composed of two radiations with different LET values, was reported to be intermediate and is determined by the absolute population size of each radical produced by radiation with different LET values. In this paper, the "x/y ratio" of alanine dosimeters returned from the containment building of the NPP is lower than that of dosimeters exposed to gamma rays. Furthermore, the ratio constantly decreased in proportion to the dose quantity, which corresponds with the installation period in the NPP. These results showed good accordance with previously reported results. Application of the above features to estimate gamma dose in mixed radiation fields is ...

show abstract

“…This molecule can therefore be considered a model system for more complex molecules, such as DNA constituents, because it has a carbon backbone as well as carboxyl and amino groups. Alanine also is important for radiation dosimetry as it is used as a secondary standard in high dose dosimetry [44][45][46]. In the solid state, L-α-alanine generates stable radicals which are suitable for use in electron paramagnetic resonance (EPR) dosimetry [47].…”

Section: Introductionmentioning

confidence: 99%

Low-energy electron collisions with the alanine molecule

2014

View full text Add to dashboard Cite

Abstract.A theoretical study on elastic electron collisions with two conformers of amino acid alanine (CH3CH(NH2)COOH) is reported. Differential and integral cross sections are computed for collision energies in the 1-10 eV range. The UK molecular R-matrix codes are used to compute scattering amplitudes within the static exchange plus polarization (SEP) approximation. Both alanine conformers have large permanent dipole moment so to calculate cross sections the Born closure procedure is included to take into account long-range interactions. Comparisons of calculated differential cross sections with available data for glycine are made and display certain similarities. Two shape resonances are detected for each conformer: a narrow one located at 2.7 eV and 3.5 eV which is probably associated with the unoccupied π * orbital of the carboxyl group, and a broader resonance at 8.6 eV and 9.8 eV.

show abstract

Advancements in accuracy of the alanine dosimetry system. Part 2. The influence of the irradiation temperature

Cited by 62 publications

References 12 publications

Alanine Dosimetry Accurately Determines Radiation Dose in Nonhuman Primates

Alanine Dosimetry Accurately Determines Radiation Dose in Nonhuman Primates

Application of Alanine/Esr Spectrum Shape Change in Gamma Dosimetry

Low-energy electron collisions with the alanine molecule

Contact Info

Product

Resources

About