| 1. |
- Swiderski, L., et al.
(författare)
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Scintillation response to gamma-rays measured at wide temperature range for Tl doped CsI with SiPM readout
- 2019
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : ELSEVIER SCIENCE BV. - 0168-9002 .- 1872-9576. ; 916, s. 32-36
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Tidskriftsartikel (refereegranskat)abstract
- A custom design cryostat was constructed to study the temperature dependence of relative light yield and non-proportionality trends of scintillators between -182 degrees C and +152 degrees C. CsI:Tl crystal response to gamma-rays and X-rays was investigated between 14 keV and 662 keV. Scintillation light was detected by a SiPM device, which was installed on a copper frame separated from the crystal and the cooling rod to enable operating the device at room temperature. The scintillation efficiency of CsI:Tl is peaked at about room temperature. The light yield of CsI:Tl at temperature close to liquid nitrogen boiling point is reduced by a factor of 15 in comparison to room temperature conditions. The non-proportionality of CsI:Tl scintillation response is high at low temperatures and is getting more proportional with increasing temperature.
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| 2. |
- Swiderski, L., et al.
(författare)
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Temperature Dependence of CsI:T1 Scintillation Pulse Shapes from-183 degrees C to+90 degrees C Measured with a SiPM Readout
- 2017
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Ingår i: 2017 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC). - : IEEE. - 9781538622827
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Konferensbidrag (refereegranskat)abstract
- A custom designed cryostat was constructed to measure the response of a CsI:T1 scintillator in temperature range from -183 degrees C up to +90 degrees C. The light readout was realized using a SiPM developed by FBK in near ultraviolet high density (NUV-HD) technology. The crystal and the SiPM were installed on separated copper frames. The crystal was cooled down by liquid nitrogen, while the SiPM was kept at temperature close to room temperature. A separation of 1 mm was kept between the crystal and the photodetector to ensure thermal isolation. The temperature of the crystal could be varied by heaters on the scintillator frame and was continuously monitored using a coil shaped resistance thermometer. The CsI:T1 scintillation decay profiles were recorded in the entire temperature range provided by the cryostat.
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| 3. |
- Swiderski, L., et al.
(författare)
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Temperature Dependence of CsI:Tl Scintillation Pulse Shapes from -183°C to +90°C Measured with a SiPM Readout
- 2018
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Ingår i: 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2017 - Conference Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781538622827
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Konferensbidrag (refereegranskat)abstract
- A custom designed cryostat was constructed to measure the response of a CsI:Tl scintillator in temperature range from - 183 ^{circ}\mathrm {C} up to +90 ^{circ}\mathrm {C}. The light readout was realized using a SiPM developed by FBK in near ultraviolet high density (NUV-HD) technology. The crystal and the SiPM were installed on separated copper frames. The crystal was cooled down by liquid nitrogen, while the SiPM was kept at temperature close to room temperature. A separation of 1 mm was kept between the crystal and the photodetector to ensure thermal isolation. The temperature of the crystal could be varied by heaters on the scintillator frame and was continuously monitored using a coil shaped resistance thermometer. The CsI:Tl scintillation decay profiles were recorded in the entire temperature range provided by the cryostat.
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| 4. |
- Gierlik, M., et al.
(författare)
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Comparative study of large NaI(Tl) and BGO scintillators for the EURopean Illicit TRAfficking Countermeasures Kit project
- 2006
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Ingår i: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9499 .- 1558-1578. ; 53:3, s. 1737-1743
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Tidskriftsartikel (refereegranskat)abstract
- The Tagged Neutron Inspection System, which is the principle of the EURITRACK project, requires efficient and inexpensive gamma-ray detectors. For this purpose, properties of 3 x 3 and 5 x 5 cylindrical BGO and NaI(TI) scintillators and of a 5 x 5 x 10 rectangular NaI(TI) scintillator were determined. 14 Light yield, energy and time resolution of the investigated crystals at the energy of few MeVs of gamma-rays are emphasized. Additionally, the crystals efficiencies calculated with Monte Carlo simulations are compared to peak-to-total ratios obtained experimentally for various combinations of PMTs and the scintillators.
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| 5. |
- Samtani, S., et al.
(författare)
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Associations between social connections and cognition: a global collaborative individual participant data meta-analysis
- 2022
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Ingår i: The Lancet Healthy Longevity. - 2666-7568. ; 3:11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Poor social connections (eg, small networks, infrequent interactions, and loneliness) are modifiable risk factors for cognitive decline. Existing meta-analyses are limited by reporting aggregate responses, a focus on global cognition, and combining social measures into single constructs. We aimed to investigate the association between social connection markers and the rate of annual change in cognition (ie, global and domain-specific), as well as sex differences, using an individual participant data meta-analysis. Methods: We harmonised data from 13 longitudinal cohort studies of ageing in North America, South America, Europe, Africa, Asia, and Australia. Studies were eligible for inclusion if they had baseline data for social connection markers and at least two waves of cognitive scores. Follow-up periods ranged from 0 years to 15 years across cohorts. We included participants with cognitive data for at least two waves and social connection data for at least one wave. We then identified and excluded people with dementia at baseline. Primary outcomes were annual rates of change in global cognition and cognitive domain scores over time until final follow-up within each cohort study analysed by use of an individual participant data meta-analysis. Linear mixed models within cohorts used baseline social connection markers as predictors of the primary outcomes. Effects were pooled in two stages using random-effects meta-analyses. We assessed the primary outcomes in the main (partially adjusted) and fully adjusted models. Partially adjusted models controlled for age, sex, and education; fully adjusted models additionally controlled for diabetes, hypertension, smoking, cardiovascular risk, and depression. Findings: Of the 40 006 participants in the 13 cohort studies, we excluded 1392 people with dementia at baseline. 38 614 individual participants were included in our analyses. For the main models, being in a relationship or married predicted slower global cognitive decline (b=0·010, 95% CI 0·000–0·019) than did being single or never married; living with others predicted slower global cognitive (b=0·007, 0·002–0·012), memory (b=0·017, 0·006–0·028), and language (b=0·008, 0·000–0·015) decline than did living alone; and weekly interactions with family and friends (b=0·016, 0·006–0·026) and weekly community group engagement (b=0·030, 0·007–0·052) predicted slower memory decline than did no interactions and no engagement. Never feeling lonely predicted slower global cognitive (b=0·047, 95% CI 0·018–0·075) and executive function (b=0·047, 0·017–0·077) decline than did often feeling lonely. Degree of social support, having a confidante, and relationship satisfaction did not predict cognitive decline across global cognition or cognitive domains. Heterogeneity was low (I2=0·00–15·11%) for all but two of the significant findings (association between slower memory decline and living with others [I2=58·33%] and community group engagement, I2=37·54–72·19%), suggesting robust results across studies. Interpretation: Good social connections (ie, living with others, weekly community group engagement, interacting weekly with family and friends, and never feeling lonely) are associated with slower cognitive decline.
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| 6. |
- Swiderski, L., et al.
(författare)
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Boron-10 loaded BC523A liquid scintillator for neutron detection in the border monitoring
- 2007
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Ingår i: 2007 IEEE Nuclear Science Symposium & Medical Imaging Conference. - : IEEE. - 1424409233 - 9781424409235 ; , s. 1389-1395
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Konferensbidrag (refereegranskat)abstract
- A BC523A liquid scintillator loaded with boron-10 was tested as a detector for both fast and thermal neutrons. Pulse shape discrimination (PSD) method based on a zero-crossing principle was applied to distinguish between neutron and gamma radiation. High quantum efficiency Photonis XP5500B photomultiplier was used to enhance light detection from the scintillator. This allowed a good registration of the energy spectrum of neutron capture events on boron-10, corresponding to about 60 keVee. The applied PSD method proved to be useful for n/γ discrimination. A good resolving power of the method was achieved even without gating on neutron capture events. A comparison with a standard BC501A liquid scintillator was done to evaluate thermal neutrons detection efficiency in BC523A.
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| 7. |
- Swiderski, L., et al.
(författare)
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Boron-10 Loaded BC523A Liquid Scintillator for Neutron Detection in the Border Monitoring
- 2008
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Ingår i: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9499 .- 1558-1578. ; 55:6, s. 3710-3716
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Tidskriftsartikel (refereegranskat)abstract
- A BC523A liquid scintillator loaded with boron-10 was tested as a detector for both fast and thermal neutrons. A pulse shape discrimination (PSD) method based on a zero-crossing principle was applied to distinguish between neutron and gamma radiation. High quantum efficiency Photonis XP5500B photomultiplier was used to enhance light detection from the scintillator. This allowed a good registration of the energy spectrum of neutron capture events on boron-10, corresponding to about 60 keV gamma-rays. The applied PSD method proved to be useful for n/gamma discrimination. A good resolving power of the method was achieved even without gating on neutron capture events. A comparison with a standard BC501A liquid scintillator was done to evaluate thermal neutrons detection efficiency in BC523A.
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| 8. |
- Swiderski, L., et al.
(författare)
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Further Study of Boron-10 Loaded Liquid Scintillators for Detection of Fast and Thermal Neutrons
- 2010
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Ingår i: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9499 .- 1558-1578. ; 57:1, s. 375-380
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Tidskriftsartikel (refereegranskat)abstract
- Boron-10 loaded liquid scintillators were studied in order to improve n/gamma separation. Pulse shape discrimination (PSD) was implemented by means of a zero-crossing (ZC) method to distinguish between gamma-rays and fast/slow neutrons. Significant progress was done for BC523A2 and EJ339A2 scintillators loaded with reduced amount of B-10 (2% and 2.5%, respectively), as compared to the results obtained earlier with BC523A loaded with 4.4% of B-10. The improvement was probably caused by the reduction of B-10 content, as indicated in the reported study. A B-10 loaded scintillator EJ309B5 based on non- flammable liquid was also studied, showing the best separation of thermal neutron capture events from fast neutrons, gamma-rays and noise.
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| 9. |
- Klamra, Wlodzimierz, et al.
(författare)
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Light yield non-proportionality of undoped YAP scintillator
- 2009
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Ingår i: Journal of Instrumentation. - : IOP Publishing. - 1748-0221. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Scintillation properties of undoped YAP crystal were studied. The emission spectra show a very intense light component at 360 nm. Analysis of the light pulse shape resulted in five components, four of them, with time constants of 38+/-2 ns, 92+/-3 ns, 7.5+/-0.5 mu s and 24+/-3 mu s, representing high light intensity. The light yield was found to be temperature dependent, N-ph=3090+/-130 ph/MeV at liquid nitrogen temperature and N-ph=1440+/-60 ph/MeV at room temperature. Also the light yield non-proportionality shows temperature dependence and is more pronounced at room temperature.
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| 10. |
- Klamra, Wlodzimierz, et al.
(författare)
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Properties of CdWO4 and ZnWO4 at Liquid Nitrogen Temperature
- 2009
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Ingår i: 2009 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-5. - 9781424439614 ; , s. 1561-1565
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Konferensbidrag (refereegranskat)abstract
- Two samples of 10 mm diameter and 10 mm height CdWO4 (CdWO) and ZnWO4 (ZnWO) scintillators were studied at room (RT) and liquid nitrogen (LN2) temperature. At room temperature the crystals were coupled to a Photonis XP3212 photomultiplier. During experiments in liquid nitrogen a Large Area Avalanche Photodiode (LAAPD) was used as a photodetector. Measurements of light output, non-proportionality of the light yield and intrinsic resolution as a function of gamma-ray energies were performed at both temperatures. The non-proportionality for the two crystals, likely CaWO4, reveals temperature dependence, to reach the same values at LN2 temperature. Intrinsic energy resolution for both crystals was also changed at LN2 comparing to the data collected at RT. The intrinsic energy resolution was improved below 100 keV and deteriorated for higher energies.
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