Wyniki wyszukiwania - Biblioteka Nauki

1

Industrial diagnostics system using gamma radiation

100%

Jakowiuk A. , Modzelewski Ł. , Pieńkos J. , Kowalska E.

Nukleonika

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2015

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tom Vol. 60, No. 3, part 2

633--636

EN

During the operation of large industrial installations, a very important task is to maintain the proper technical state. In the event of an emergency, it is vital to locate the place of occurrence as soon as possible. In solving this type of problem, it often helps to apply the methods of measurement associated with ionizing radiation. One of these methods is the gamma scanning. The purpose of this type of measurement is the detection and localization of disturbance of technological processes which may result in incorrect decomposition the flowing medium and workpiece (sediments, congestion) as well as damage to the internal constructions. A particularly: (i) preventive diagnosis – early detection of installation failure; (ii) rationalization of repairs and renovations – to determine the need to take or not to take remedial action; (iii) quick and precise installation inspections – to gain knowledge of the technical condition and technological installations; (iv) indication of worn parts and posing a threat – diagnostics of the technical condition installation; (v) forecasting the useful lifetime of equipment.

2

Heterogeneous radiolysis of urea. Implications in astrobiology and prebiotic chemistry

80%

Abigail E. Cruz-Hernández, A. E. , Colin-Garcia M. , Heredia-Barbero A. , Negron-Mendoza A. , Ramos-Bernal S.

Open Chemistry

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2015

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tom 13

|

nr 1

EN

Urea is an organic molecule present in most living organisms. Historically, it was the first organic molecule synthesized in the laboratory. In prebiotic chemistry, urea readily forms in different laboratory simulations using different energy sources. Furthermore, the role of solid surfaces, particularly minerals, might have been crucial to increase the complexity of the organic matter which may have led to the subsequent emergence of life on Earth. In this work, the radiolysis of urea in presence of a clay is studied to determine to what extent the mineral surfaces influence the decomposition of organics. The results indicate that urea is relatively stable to ionizing radiation in aqueous solutions and up to 20 kGy no decomposition is observed. Moreover, the presence of sodium montmorillonite, by a mechanism until now unknown, affects the radiolytic behavior and urea remains in the heterogeneous solution without a change in concentration even at very high doses (140 kGy). These results indicate that solids could have protected some organics, like urea, from degradation enabling them to remain in the environment on the primitive Earth.

3

Application of gamma radiation and physicochemical treatment to improve the bioactive properties of chitosan extracted from shrimp shell

80%

Aktar J. , Hasan Z. , Afroz T. , or-Rashid H. , Pramanik K.

Nukleonika

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2017

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tom Vol. 62, No. 4

245--251

EN

The aim of this study is to exploit a suitable chitosan extraction method from the chitin of indigenous shrimp shells by employing different physicochemical treatments and to improve different bioactive properties of this extracted chitosan (CS) by applying gamma radiation. Chitin was prepared from shrimp shell by pretreatment (deproteination, demineralization and oxidation). Chitosan was extracted from chitin by eight different methods varying different physicochemical parameters (reagent concentration, temperature and time) and assessed with respect to the degree of deacetylation, requirement of time and reagents. The method where chitin was repeatedly treated with 121°C for 30 min with 20 M NaOH, produced the highest degree of deacetylation (DD) value (92%) as measured by potentiometric titration, with the least consumption of time and chemicals, and thus, selected as the best suitable extraction method. For further quality improvement, chitosan with highest DD value was irradiated with different doses (i.e., 5, 10, 15, 20 and 50 kGy) of gamma radiation from cobalt-60 gamma irradiator. As the radiation dose was increased, the molecular weight of the wet irradiated chitosan, as measured by the viscosimetric method, decreased from 1.16 × 105 to 1.786 × 103 , 1.518 × 103 , 1.134 × 103 , 1.046 × 103 and 8.23 × 102 dalton, respectively. The radiation treatment of chitosan samples increased the antimicrobial activity signifi cantly in concentration dependent manner on both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria, as determined by the well-diffusion method. Four to fi ve percent wet chitosan treated with a radiation dose range of 5.0–10.0 kGy rendered the highest antimicrobial activity with least energy and time consumption. Solubility, water binding capacity (WBC) and fat binding capacity (FBC) also improved due to irradiation of chitosan.

4

Mechanical design of the gamma blockers for the high-energy beam transport region of the European Spallation Source

80%

Wojciechowski M. , Szymczyk K. , Wronka S.

Nukleonika

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2023

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tom Vol. 68, No. 3

77--80

EN

The European Spallation Source (ESS) is a collaboration of 13 European countries to build the world’s most powerful neutron source for research. The project, situated in the south of Sweden, is approaching the end of the construction phase, and the fi rst scientifi c results are planned for 2023. This paper gives an overview of mechanical design of the gamma blockers (GBs) in the accelerator to target (A2T) and dump line (DmpL) sections. The presence of GBs in the beam line should limit the gamma radiation emitted from the activated tungsten target and beam dump to allow the safe access of the staff to the machine. The presented design allows for effi cient operation and the same shutting time independently of the vacuum status.

5

Study of some physicochemical and rheological properties of irradiated honey

80%

Bera A. , Almeida-Muradian L. G. , Sabato S. F.

Nukleonika

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2008

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tom Vol. 53, suppl. 2

85--87

EN

Honey is a sweet substance produced by bees, well appreciated in many places and its consumption has been increased either as raw material or as a food ingredient. Its use as food by the consumer, or even for exportation, implies safety inherent in its quality and processing control. Gamma radiation can be applied in food or ingredients for many objectives like pathogens microorganisms’ reduction, disinfestations, and sterilization. The aim of this work was to verify some physicochemical modifications, as well as rheological evaluation of honey submitted to irradiation at 10 kGy. The physicochemical parameters analyzed were: moisture, HMF, free acidity, pH, sugars and ash. The rheological behavior was measured at different temperatures. The results indicated that few changes occurred; the rheological behavior was not impaired and did not present any significant physicochemical alteration.

6

Gamma-radiation induced degradation random walk error in interferometer fiber optic gyroscope

80%

Du S. , Wang X. , Lin S. , Zhang C.

Optica Applicata

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2011

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tom Vol. 41, nr 4

953--959

EN

Gamma-radiation induced random walk error (RWE) of interferometer fiber optic gyroscope (IFOG) is presented in this paper. Testing was performed at the components and system level with an expanded version of a closed-loop operational fiber optic gyroscope. Primary concerns include attenuation to total dose, angle random walk, and bias stability degradation as a function of dose. Closed-loop transient noise results are evaluated based on radiation test of the 400 m fiber coil. Based on the test result, a random walk coefficient (RWC) prediction model in radiation environment, which is obtained by embedding polarization-maintaining (PM) fiber loss expression into the RWC model, was built following a power law of dose. An IFOG RWC in space radiation environment was predicted from radiation dose rate by the prediction model. The RWC of the IFOG is limited by the detector thermal noise above 1 kGy radiation and the RWC prediction model is verified by radiation experiment.

7

Time Stability of Mechanical and Dielectric Parameters in the PZT Type Piezoceramics After Gamma Radiation: revision

80%

Zachariasz R. , Czerwiec M. , Ilczuk J.

Molecular and Quantum Acoustics

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2006

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tom Vol. 27

307-314

EN

Doped PZT ceramics, with the chemical composition (Pb0.9Ba0.1)(Zr0.53Ti0.47)O3+ 2% mol. Nb2O5was the tested material. It is characterized by high dielectric values (e > 1300, tgd = 0.024) and electromechanical coupling coefficient (kp> 0.5). Due to good mechanical parameters (E = 102 GPa at T = 293 K) and high stability of parameters at elevated temperatures, the ceramics is used in electromechanical transducers at low frequency. Objective of this work was the investigation of the gamma radiation influence of the electromechanical properties of such ceramics.

8

Gamma radiation calculations and gamma blocker design for the high-energy beam transport region of the European Spallation Source

80%

Szymczyk K. S. , Wronka S.

Nukleonika

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2021

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tom Vol. 66, No. 3

99--102

EN

The purpose of this paper is to present the Monte-Carlo calculations performed to design a special element called gamma blocker (GB), necessary to stop the gamma radiation in the Accelerator-to-Target (A2T) section of European Spallation Source (ESS) linac. Very high levels of gamma radiation emitted backward from the activated target through the beam pipe could effectively block any human intervention close to the beam transport system. The residual dose rate in the linac tunnel was calculated without and with different GBs as a function of time. The fi nal GB material and dimensions are proposed.

9

Społeczno-techniczne determinanty odkrycia kosmicznych źródeł promieniowania gamma

80%

Roskal Z. E.

Kwartalnik Historii Nauki i Techniki

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2013

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tom R. 58, nr 3

81--97

EN

The paper deals with the problem of technical and social conditions of scientific discovery. Exemplified by the discovery of cosmic gamma radiation, the role of develop ment of technology in founding of new branches of astronomy (gamma- ray astronomy) is here presented. Some important social factors, which significantly accelerated the for mation of the gamma-ray astronomy, were also recognized in the paper. Above all, how ever, the concept of scientific discovery was supported in the paper - a concept of a scientific discovery as a multi-threaded, technical and social project which, due to its complexity and phasality, is not subject to reconstruction as a simple event to which we may assign authorship of a particular person or accurately determine the coordinates of the time. Modern science is, among others, characterized by the fact that any research projects taken up within its framework are highly complex and require cooperation of not only scholars from different research and scientific centers, but also engineers and technicians whose contribution to scientific discovery is comparable to the contribution of the scholars themselves.

10

Recent studies of irradiated mangoes in Brazil : a trend towards commercial approach

80%

Sabato S. F. , Silva J. M. , Cruz J. N. , Broisler P. O. , Rela P. R. , Salmieri S. , Lacroix M.

Nukleonika

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2008

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tom Vol. 53, suppl. 2

77--79

EN

Mango is an important commodity to our country as Brazil is a great producer and exporter of tropical fruits. Nowadays, Mexico and India are the main exporters of mango in the world and Brazil occupies the third position in this ranking. As these countries have adopted gamma radiation as a phytosanitary treatment and signed a bilateral agreement with the United States for exporting mango to this country, Brazil has to be up-to-dated with this trend. The Institute of Nuclear and Energy Researches together with field producers in the northeastern region and partners like the International Atomic Energy Agency, the Canadian Irradiation Center and Empresa Brasileira de Agropecuária joined to demonstrate this technology, its application and its commercial feasibility. The whole project was structured in two parts that involved around 1300 mangoes. The first step consisted mainly in studying the quality of irradiated mangoes within our territory, using a multipurpose semi-commercial cobalt facility, and comparing two harvesting points of the fruits. The second one was an international consignment of irradiated fruits from Brazil to Canada, where the control sample consisted of fruits treated with a hot water dip. The financial part of the feasibility study covers the scope of the investment, including the net working capital and production costs. In a summarized way to express, the results from physicochemical analysis and sensory evaluation were favorable, indicating that gamma radiation is a potential quarantine treatment.

11

Development of crystals based on cesium iodide for measurements of gamma radiation and alpha particles

70%

Pereira M. C. C. , Filho T. M. , Hamada M. M.

Nukleonika

|

2009

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tom Vol. 54, No. 3

151-155

EN

During the past 50 years, scintillators have been among the most important nuclear radiation detectors. Inorganic scintillators are widely used in experimental nuclear physics, high energy physics, nuclear medicine, nuclear tomography, environmental studies and many other fields of use. Scintillation crystals based on cesium iodide (CsI) are matters of relatively low hygroscopy, high atomic number, easy handling and low cost, characteristics that favor their use as radiation detectors. In this work, the growth of pure CsI crystals, CsI:Br and CsI:Pb, using the Bridgman technique, is described. Ions of divalent lead (Pb2+) doped in the crystal structures are efficient emission centers and their application as scintillators is still the reason for intensive studies. Recently, promising results have been found for crystals of CsI doped by bromine (Br) for their use as radiation detectors. The concentration of the bromine doping element (Br) was studied in the range from 1.5 × 10–1 M to 10–2 M and the lead (Pb) in the range from 10–2 M to 5 × 10–4 M. To evaluate the scintillators developed, systematic measurements were carried out for luminescence emission and luminescence decay time for gamma radiation, Vickers microhardness assays, and analysis of crystals response to the gamma radiation, in the energy range from 350 keV to 1330 keV, and alpha particles from a 241Am source, with energy of 5.54 MeV. The obtained values for luminescence decay time for CsI:Br and CsI:Pb crystals, were from 13 to 19 ns.

12

Tartrazine Solution as Dosimeter for Gamma Radiation Measurement

70%

Gobara M. , Baraka A.

International Letters of Chemistry, Physics and Astronomy

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2014

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tom Vol. 14, iss. 1

106--117

EN

In this study, Tartrazine aqueous solution was investigated as a simple low-dose dosimeter in the range of 20-500 Gy for the high ionizing radiation, gamma ray. Gradual bleaching of Tartarzine solution was observed with dose by measuring the absorbance of Tartarzine-solutions at specified wavelength, λmax = 428 nm. Tartrazine concentration (10–4, 5 ×10–4 and 10–3 M) and solution-initial pH value (5, 7 and 9) were considered as factors affecting degree of bleaching. It was found that Tartarzine-solution color was diminished gradually with selected dose range due to breakdown of the azo bond. The rate of bleaching increases with the increase of solution-initial pH. Increase of Tartarzine-concentration causes widening of range to which solution is susceptible. The post-irradiated effect (24 hours) was found to cause more bleaching. The sensitivity of Tartrazine solution is not regular with the Tartarzine-concentration and regular with pH.

13

Radiation activities and application of ionizing radiation on cultural heritage at ENEA Calliope gamma facility (Casaccia R.C., Rome, Italy)

70%

Baccaro S. , Cemmi A.

Nukleonika

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2017

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tom Vol. 62, No. 4

261--267

EN

Since the 1980s, research and qualification activities are being carried out at the 60Co gamma Calliope plant, a pool-type irradiation facility located at the Research Centre ENEA-Casaccia (Rome, Italy). The Calliope facility is deeply involved in radiation processing research and on the evaluation and characterization of the effects induced by gamma radiation on materials for different applications (crystals, glasses, optical fibres, polymers and biological systems) and on devices to be used in hostile radiation environment such as nuclear plants, aerospace and high energy physics experiments. All the activities are carried out in the framework of international projects and collaboration with industries and research institutions. In the present work, particular attention will be paid to the cultural heritage activities performed at the Calliope facility, focused on two different aspects: (a) conservation and preservation by bio-deteriogen eradication in archived materials, and (b) consolidation and protection by degraded wooden and stone porous artefacts consolidation.

14

Effect of Gamma Irradiation on the Optical Properties of Mg doped CdO Thin films deposited by Spray Pyrolysis

70%

Hassouni M. H. , Mishjil K. A. , Chiad S. S. , Habubi N. F.

International Letters of Chemistry, Physics and Astronomy

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2013

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tom Vol. 11

26--37

EN

Thin films of CdO and 9 % Mg doped CdO doped have been prepared using spray pyrolysis technique. Transmission and absorption spectra were recorded in order to estimate these films. The deposited thin films were exposed to γ - rays. We have studied the transmission, absorptions and absorption coefficient as a function of photon energy before and after irradiation. The optical constants such as: reflectance, extinction coefficient, refractive index, real and imaginary parts of the dielectric constant and the electrical conductivity were calculated also.

15

Comparison of the effects of bleomycin and ionizing radiation in two sublines of murine lymphoma L5178Y

70%

Kruszewski M. , Zaim J. , Grądzka I. , Szumiel I.

Nukleonika

|

2001

|

tom Vol. 46, nr 3

81-86

EN

We compared the effects of bleomycin (BLM) and ionizing radiation on two sublines of murine lymphoma L5178Y (LY): LY-R, radiation resistant and LY-S, radiation sensitive. This radiosensitivity difference is related to the ability to rejoin DNA double strand breaks. LY-S cells were about two times more sensitive to BLM than LY-R, similarly as in the case of sensitivity to X rays. Since there was no difference in the P-glycoprotein-related drug transport system between the sublines, it could be expected that the enhanced sensitivity of LY-S cells to BLM was caused by the DNA repair defect. Growth disturbances in BLM treated cell populations were proportional to the lethal effect and their duration was observed until elimination of dead cells (3-6 days after 50 ěM BLM, 1 h at 37oC). There was no slow growth phase accompanied by normal viability, as previously described for X-irradiated LY-S cells. Initial DNA damage, estimated with the single cell gel electrophoresis method was linearly related to BLM dose in LY-S cells; in LY-R cells - in the low dose range (up to 10 ěM) - there was more damage than in LY-S cells, however, at higher doses the dose - effect curves became identical. The doseeffect relationship for ă rays was linear and identical in both cell sublines. DNA damage distribution in BLM treated cells was much less uniform as compared to that in irradiated cells and indicated the presence of cells with severely damaged DNA, a feature typical for BLM action in vitro.

16

Using bone powder for dosimetric system EPR response under the action of γ irradiation

60%

Ziaie F. , Stachowicz W. , Strzelczak G. , Al-Osaimi S.

Nukleonika

|

1999

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tom Vol. 44, nr 4

603-608

EN

Two sets of samples of the bovine bone powder and α-l-alanine crystalline powder were irradiated in a 60Co source using the doses from 5 kGy up to 120 kGy while recorded signals were subsequently measured with the EPR spectrometer at room temperature in the air. Quantitative data related to the absorbed dose of radiation were collected. Dose versus EPR signal intensity curves for both kinds of samples were constructed and evaluated.

PL

W pracy poddano napromieniowaniu w źródle Co-60 dawkami od 5 kGy do 120 kGy dwa zestawy próbek, sproszkowaną kość wołową oraz sproszkowaną krystaliczną α-Ianinę, a następnie przeprowadzono na spektrometrze EPR pomiary ilościowe zarejestrowanych sygnałów w temperaturze pokojowej, przy dostępie powietrza. Zgromadzono ilościowe dane odnoszące się do absorbowanej dawki promieniowania. Wykreślono krzywe zależności dawka - intensywność sygnału dla obu rodzajów próbek oraz dokonano oceny uzyskanych wyników.

17

Odtwarzanie i przekazywanie jednostki mocy kermy w powietrzu dla promieniowania gamma

60%

Kaczorowska E. , Derlaciński M. , Knyziak A. B.

Metrologia : biuletyn informacyjny Głównego Urzędu Miar

|

2009

|

tom nr 3

17--25

PL

W niniejszej pracy przedstawiamy stanowisko pomiarowe w Głównym Urzędzie Miar służące do odtwarzania i przekazywania jednostki kermy w powietrzu i jednostki mocy kermy w powietrzu w polu promieniowania gamma radionuklidów 137Cs i 60C.

EN

In this work we introduce the measurement system at the Central Office of Measures (GUM), which is used for reproduction and dissemination of the unit of kerma rate in air that uses gamma rays of radionuclides 137Cs and 60Co.

18

Effect of low doses of gamma radiation on the mortality, morphology and pa-thogenicity of Heterorhabditis megidis (Poinar, Jackson, Klein 1987)

60%

Poleszczuk O. , Pezowicz E. , Kamionek M. , Jarmuł J.

Chemia i Inżynieria Ekologiczna

|

2006

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tom Vol. 13, nr 1-2

99-103

EN

The effect of low doses of ionizing radiation on the development, morphometry and pathogenicity of H. megidis was studied. Gamma rays i.e. electromagnetic wave emitted by nuclei of excited radioactive atoms of 60Co were used in experiments. The increase of radiation doses was found to decrease body length of adult individuals but did not affect the dimensions of invasive larvae. The lowest of applied doses increased twice the intensity of infection of insects. 0.01 kGy was the dose that did not result in nematode sterilisation.

PL

Przeprowadzono badania nad wplywem małych dawek promieniowania jonizującego na rozwój, morfometrię i patogenność H. megidis. W doświadczeniach wykorzystano promienie gamma, czyli falę elektromagnetyczną, emitowaną przez jądra wzbudzonych atomów promieniotwórczych - 60Co. Stwierdzono, że wzrost dawki promieniowania wpływa na obniżenie długości ciała osobników dorosłych, natomiast nie wpływa na wymiary larw inwazyjnych. Najmniejsza z zastosowanych dawek dwukrotnie zwiększała intensywność porażenia owadów. Dawką, która nie powoduje sterylizacji nicieni jest 0,01 kGy.

19

Needle detector of X-ray and gamma radiation

60%

Domański G. , Szabatin R. , Brzeski P. , Konarzewski B.

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2017

|

tom T. 7, nr 1

121--124

EN

The article presents the developed structure of the novel needle proportional gas detector (NPC – Needle Proportional Counter) used for the detection of X-rays and gamma rays. The advantage of the detector is its simple mechanical construction and the possibility of detection of incident radiation in a direction parallel to the needle. The measured energy spectrum of the isotope Fe-55 by means of the developed detector is presented.

PL

Artykuł przedstawia opracowaną konstrukcję nowego typu gazowego detektora igłowego, służącego do detekcji promieniowania X i gamma. Zaletą detektora jest jego prosta konstrukcja mechaniczna i możliwość detekcji promieniowania w kierunku równoległym do igły. Zmierzono widmo energetyczne izotopu Fe-55 opracowanym detektorem.

20

Influence of gamma and proton radiations on the absorption, photoluminescence and birefringence of lithium niobate single crystals doped with Cu, Fe and Cr ions

60%

Kaczmarek S.

Nukleonika

|

2001

|

tom Vol. 46, nr 2

63-69

EN

The results of investigations of the influence of gamma and proton radiations on absorption, luminescence and birefringence of either pure or Cu, Fe and Cr doped LiNbO3 single crystals were presented. A method of birefringence dispersion testing on the entire areas of plane-parallel plates of LiNbO3 crystals has been illustrated by the influence of both types of irradiation on pure and Fe, Cr and Cu-doped LiNbO3 wafers. It was found that Li NbO3 LN:Cu single crystal shows a different behavior compared with other investigated crystals. First of all it exhibits lower susceptibility to gammarays, the absence of 500 nm additional absorption, and a strong proton susceptibility observed in polarimeter measurements.