New features of hot intraband luminescence for fast timing

Omelkov, Sergey; Nagirnyi, V.; Vasil’ev, A. N.; Kirm, M.

doi:10.1016/j.jlumin.2016.03.039

Cited by 54 publications

(20 citation statements)

References 35 publications

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“…The photodetector used for the readout is a fast hybrid PMT and the instrumental response (IRF) function of the whole setup has been obtained measuring the IBL of Li 2 MoO 4 . 11 The IRF has a full width half maximum of~130 ps 34 and this is the reason for the unresolved first decay component expressed as 20 ± 20 ps.…”

Section: Resultsmentioning

confidence: 99%

“…Normally, for standard state-of-the-art materials, photon-time density fluctuates~1 photon/MeV per picosecond just from the scintillation mechanisms, not considering Cherenkov 10 or hot intraband luminescence (IBL). 11 In order to increase the prompt photon emission yield, we propose to replace the usual bulk scintillator pixel by a sampling configuration, so that the recoil electron from a photoelectric conversion created in the dense host scintillator can eventually reach a fast emitting nano-scintillator layer. 12 In this way, prompt or relatively prompt emission from nanocrystals could be added to the standard scintillating signal and help to decrease the overall timing jitter associated to particle detection.…”

Section: Introductionmentioning

confidence: 99%

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On the use of CdSe scintillating nanoplatelets as time taggers for high-energy gamma detection

et al. 2019

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The technological challenge imposed by the time resolution essential to achieve real-time molecular imaging calls for a new generation of ultrafast detectors. In this contribution, we demonstrate that CdSe-based semiconductor nanoplatelets can be combined with standard scintillator technology to achieve 80 ps coincidence time resolution on a hybrid functional pixel. This result contrasts with the fact that the overall detector light output is considerably affected by the loss of index-light-guiding. Here, we exploit the principle of 511 keV energy sharing between a high-Z, high stopping power bulk scintillator, and a nano-scintillator with sub-1 ns radiative recombination times, aiming at a breakthrough in the combined energy and time resolution performance. This proof-of-concept test opens the way to the design and study of larger size sensors using thin nanocomposite layers able to perform as efficient time taggers in a sampling detector geometry of new generation. npj 2D Materials and Applications (2019) 3:37; https://doi.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

On the use of CdSe scintillating nanoplatelets as time taggers for high-energy gamma detection

et al. 2019

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“…Спектры ИКЛ были скорректированы на спектральную чувствительность системы регистрации. Измерения проводились в Институте физики Тартуского университета (Тарту, Эстония) [16]. Для измерения ки-нетики затухания ФЛ использовался лазер типа DTC-389 (λ exc = 263 nm (4.715 eV), частота импульсов 1000 Hz, мощность 12 µJ), измерения проведены в Уральском федеральном университете.…”

Section: объекты и методы исследованияunclassified

“…Такой быстрый ком-понент в кинетике затухания ИКЛ с τ < 1 ns наблю-дался во многих широкозонных диэлектриках при воз-буждении ИКЛ импульсами электронов наносекундной длительности и связывался с проявлением внутризонной люминесценции [20]. В последнее время быстрая внутри-зонная люминесценция интенсивно изучается с примене-нием пикосекундных электронных пучков [16]. Здесь же мы отметим только наличие такого же быстрого компо-нента в кинетике затухания РЛ при возбуждении мощны-ми импульсами СИ, на что исследователями ранее не об-ращалось внимание ввиду незначительного вклада этого компонента на фоне яркой РЛ исследуемых кристаллов.…”

Section: результаты экспериментов и обсуждениеunclassified

Люминесценция примесных Ce-=SUP=-3+-=/SUP=- центров в кристаллах KH-=SUB=-2-=/SUB=-PO-=SUB=-4-=/SUB=-:Ce

Пустоваров¹,

Огородников²,

Omelkov

2018

Физика Твердого Тела

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Спектры фото-, рентгено-и катодолюминесценции монокристаллов KH 2 PO 4 : Ce содержат неэлементар-ную полосу излучения с энергией 3.55 eV и временем затухания 27−33 ns. Она сформирована быстрыми излучательными межконфигурационными d → f переходами между возбужденным и основным состояниями ионов Ce 3+ , причем основное расщеплено кристаллическим полем. В исследованном диапазоне концентраций (0.5−3 · 10 −2 mass. %) ионы Ce 3+ входят в кристаллическую решетку KH 2 PO 4 : Ce как ионы замеще-ния. Локальная компенсация заряда реализована дефектами кристаллической структуры, вызывающими люминесценцию с большим стоксовым сдвигом в районе 2.4−2.2 eV. Наличие дефектов водородной подрешетки снижает эффективность транспорта энергии свободными носителями заряда к центрам свечения. Взаимодействие дефектов и примесных центров проявляется как медленное инерционное разгорание выхода стационарной рентгенолюминесценции Ce 3+ центров.Работа поддержана Министерством образования и науки Российской Федерации (базовая часть госу-дарственного задания, проект 3.8302.2017/8.9), грантом STSM от COST Action TD1401 "FAST" и Estonian Research Council (проекты PUT1081 и IUT2-26).Результаты ИКЛ получены в рамках короткой исследовательской миссии (short-time scientific mission, STSM), поддержанной COST Action TD1401 " FAST". Исследование рентгенолюминесценции проведено в Сибирском центре синхротронного и терагерцового излучения в Институте ядерной физики СО РАН.

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“…LuAG:Pr [7]. These prompt photons are produced most likely by the Cherenkov effect, although some other contributions, for instance from hot-intraband-luminescence are not excluded [8]. The Cherenkov effect has already been studied in several publications and its potential influence to the CTR discussed [7,9,10].…”

mentioning

confidence: 99%

Measurement of intrinsic rise times for various L(Y)SO and LuAG scintillators with a general study of prompt photons to achieve 10 ps in TOF-PET

Gundacker

Auffray²,

Pauwels³

et al. 2016

Phys. Med. Biol.

151

144

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The coincidence time resolution (CTR) of scintillator based detectors commonly used in positron emission tomography is well known to be dependent on the scintillation decay time (τd) and the number of photons detected (n'), i.e. CTR proportional variant √τd/n'. However, it is still an open question to what extent the scintillation rise time (τr) and other fast or prompt photons, e.g. Cherenkov photons, at the beginning of the scintillation process influence the CTR. This paper presents measurements of the scintillation emission rate for different LSO type crystals, i.e. LSO:Ce, LYSO:Ce, LSO:Ce codoped Ca and LGSO:Ce. For the various LSO-type samples measured we find an average value of 70 ps for the scintillation rise time, although some crystals like LSO:Ce codoped Ca seem to have a much faster rise time in the order of 20 ps. Additional measurements for LuAG:Ce and LuAG:Pr show a rise time of 535 ps and 251 ps, respectively. For these crystals, prompt photons (Cherenkov) can be observed at the beginning of the scintillation event. Furthermore a significantly lower rise time value is observed when codoping with calcium. To quantitatively investigate the influence of the rise time to the time resolution we measured the CTR with the same L(Y)SO samples and compared the values to Monte Carlo simulations. Using the measured relative light yields, rise- and decay times of the scintillators we are able to quantitatively understand the measured CTRs in our simulations. Although the rise time is important to fully explain the CTR variation for the different samples tested we determined its influence on the CTR to be in the order of a few percent only. This result is surprising because, if only photonstatistics of the scintillation process is considered, the CTR would be proportional to the square root of the rise time. The unexpected small rise time influence on the CTR can be explained by the convolution of the scintillation rate with the single photon time resolution (SPTR) of the photodetector and the photon travel spread (PTS) in the crystal. The timing benefits of prompt photons at the beginning of the scintillation process (Cherenkov etc) are further studied, which leads to the conclusion that the scintillation rise time, SPTR and PTS have to be lowered simultaneously to fully profit from these fast photons in order to improve the CTR significantly.

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New features of hot intraband luminescence for fast timing

Cited by 54 publications

References 35 publications

On the use of CdSe scintillating nanoplatelets as time taggers for high-energy gamma detection

On the use of CdSe scintillating nanoplatelets as time taggers for high-energy gamma detection

Люминесценция примесных Ce-=SUP=-3+-=/SUP=- центров в кристаллах KH-=SUB=-2-=/SUB=-PO-=SUB=-4-=/SUB=-:Ce

Measurement of intrinsic rise times for various L(Y)SO and LuAG scintillators with a general study of prompt photons to achieve 10 ps in TOF-PET

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