| Records |
| Author |
Lobanov, Y.V.; Tong, C.-Y.E.; Hedden, A.S.; Blundell, R.; Voronov, B.M.; Gol'tsman, G.N. |
| Title |
Direct measurement of the gain and noise bandwidths of HEB mixers |
Type |
Journal Article |
| Year |
2011 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
Volume  |
21 |
Issue |
3 |
Pages |
645-648 |
| Keywords |
waveguide NbN HEB mixers |
| Abstract |
The intermediate frequency (IF) bandwidth of a hot electron bolometer (HEB) mixer is an important parameter of the mixer, in that it helps to determine its suitability for a given application. With the availability of wideband low noise amplifiers, it is simple to measure the performance of an HEB mixer over a wide range of IF at a fixed LO frequency using the standard Y-factor method. This in-situ method allows us to measure both the gain and noise bandwidths simultaneously. We have also measured mixer output impedance with a vector network analyser. Intrinsic time constant has been extracted from the impedance data and compared to the mixer's bandwidths determined from receiver Y-factor measurement. |
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RPLAB @ gujma @ |
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720 |
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| Author |
Kawakami, A; Saito, S.; Hyodo, M. |
| Title |
Fabrication of nano-antennas for superconducting Infrared detectors |
Type |
Journal Article |
| Year |
2011 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
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| Volume |
21 |
Issue |
3 |
Pages |
632-635 |
| Keywords |
optical antennas, NbN/MgO/NbN/TiN/Al HEB, dipole antennas, IR, infrared |
| Abstract |
To improve the response performance of superconducting infrared detectors, we have developed a fabrication process for nano-antennas. A nano-antenna consists of a dipole antenna, and a superconducting thin film strip placed in the antenna's center. By measuring the transition temperature of the superconducting strips, we confirmed that their superconductivity maintained a good condition after the nano-antenna fabrication process. We also evaluated nano-antenna characteristics using Fourier transform infrared spectroscopy. The evaluated antenna length and width were respectively set at around 2400 nm and 400 nm, and the antennas were placed at intervals of several micrometers around the area of 1 mm2 . In an evaluation of spectral transmission characteristics, clear absorption caused by antenna effects was observed at around 1400 cm-1. High polarization dependencies were also observed. |
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761 |
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| Author |
Galeazzi, Massimiliano |
| Title |
Fundamental noise processes in TES devices |
Type |
Journal Article |
| Year |
2011 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
| Volume |
21 |
Issue |
3 |
Pages |
267-271 |
| Keywords |
TES, Johnson noise, phonon noise, excess noise, flux-flow noise, thermal fluctuation noise |
| Abstract |
Microcalorimeters and bolometers are noise-limited devices, therefore, a proper understanding of all noise sources is essential to predict and interpret their performance. In this paper, I review the fundamental noise processes contributing to Transition Edge Sensor (TES) microcalorimeters and bolometers and their effect on device performance. In particular, I will start with a simple, monolithic device model, moving to a more complex one involving discrete components, to finally move to today's more realistic, comprehensive model. In addition to the basic noise contribution (equilibrium Johnson noise and phonon noise), TES are significantly affected by extra noise, which is commonly referred to as excess noise. Different fundamental processes have been proposed and investigated to explain the origin of this excess noise, in particular near equilibrium non-linear Johnson noise, flux-flow noise, and internal thermal fluctuation noise. Experimental evidence shows that all three processes are real and contribute, at different levels, to the TES noise, although different processes become important at different regimes. It is therefore time to discard the term “excess noise” and consider these terms part of the “fundamental noise processes” instead. |
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Recommended by Klapwijk |
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914 |
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| Author |
Ryabchun, Sergey; Tong, Cheuk-Yu Edward; Blundell, Raymond; Gol'tsman, Gregory |
| Title |
Stabilization scheme for hot-electron bolometer receivers using microwave radiation |
Type |
Journal Article |
| Year |
2009 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
| Volume |
19 |
Issue |
1 |
Pages |
14-19 |
| Keywords |
HEB, mixer, Allan variance, stabilization, radiometer equation |
| Abstract |
We present the results of a stabilization scheme for terahertz receivers based on NbN hot-electron bolometer (HEB) mixers that uses microwave radiation with a frequency much lower than the gap frequency of NbN to compensate for mixer current fluctuations. A feedback control loop, which actively controls the power level of the injected microwave radiation, has successfully been implemented to stabilize the operating point of the HEB mixer. This allows us to increase the receiver Allan time to 10 s and also improve the temperature resolution of the receiver by about 30% in the total power mode of operation. |
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1051-8223 |
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RPLAB @ lobanovyury @ |
Serial |
559 |
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| Author |
Ryabchun, Sergey; Tong, Cheuk-Yu Edward; Paine, Scott; Lobanov, Yury; Blundell, Raymond; Goltsman, Gregory |
| Title |
Temperature resolution of an HEB receiver at 810 GHz |
Type |
Journal Article |
| Year |
2009 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
| Volume |
19 |
Issue |
3 |
Pages |
293-296 |
| Keywords |
HEB mixer |
| Abstract |
We present the results of direct measurements of the temperature resolution of an HEB receiver operating at 810 GHz, in both continuum and spectroscopic modes. In the continuum mode, the input of the receiver was switched between black bodies with different physical temperatures. With a system noise temperature of around 1100 K, the receiver was able to resolve loads which differed in temperature by about 1 K over an integration time of 5 seconds. This resolution is significantly worse than the value of 0.07 K given by the radiometer equation. In the spectroscopic mode, a gas cell filled with carbonyl sulphide (OCS) gas was used and the emission line at 813.3537060 GHz was measured using the receiver in conjunction with a digital spectrometer. From the observed spectra, we determined that the measurement uncertainty of the equivalent emission temperature was 2.8 K for an integration time of 0.25 seconds and a spectral resolution of 12 MHz, compared to a 1.4 K temperature resolution given by the radiometer equation. This relative improvement is due to the fact that at short integration times the contribution from 1/f noise and drift are less dominant. In both modes, the temperature resolution was improved by about 40% with the use of a feedback loop which adjusted the level of an injected microwave radiation to maintain a constant operating current of the HEB mixer. This stabilization scheme has proved to be very effective to keep the temperature resolution of the HEB receiver to close to the theoretical value given by the radiometer equation. |
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no |
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636 |
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Xiaolong Hu; Holzwarth, C.W.; Masciarelli, D.; Dauler, E.A.; Berggren, K.K. |
| Title |
Efficiently coupling light to superconducting nanowire single-photon detectors |
Type |
Journal Article |
| Year |
2009 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
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| Volume |
19 |
Issue |
3 |
Pages |
336-340 |
| Keywords |
optical antennas; SNSPD |
| Abstract |
We designed superconducting nanowire single-photon detectors (SNSPDs) integrated with silver optical antennae for free-space coupling and a dielectric waveguide for fiber coupling. According to our finite-element simulation, (1) for the free-space coupling, the absorptance of the NbN nanowire for TM-polarized photons at the wavelength of 1550 nm can be as high as 96% by adding silver optical antennae; (2) for the fiber coupling, the absorptance of the NbN nanowire for TE-like-polarized photons can reach 76% including coupling efficiency at the wavelength of 1550 nm by adding a silicon nitride waveguide and an inverse-taper coupler. |
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RPLAB @ gujma @ |
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647 |
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Yang, J.K.W.; Kerman, A.J.; Dauler, E.A.; Cord, B.; Anant, V.; Molnar, R.J.; Berggren, K.K. |
| Title |
Suppressed critical current in superconducting nanowire single-photon detectors with high fill-factors |
Type |
Journal Article |
| Year |
2009 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
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| Volume |
19 |
Issue |
3 |
Pages |
318-322 |
| Keywords |
SNSPD |
| Abstract |
In this work we present a new fabrication process that enabled the fabrication of superconducting nanowire single photon detectors SNSPD with fill-factors as high as 88% with gaps between nanowires as small as 12 nm. This fabrication process combined high-resolution electron-beam lithography with photolithography. Although this work was motivated by the potential of increased detection efficiency with higher fill-factor devices, test results showed an unexpected systematic suppression in device critical currents with increasing fill-factor. |
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RPLAB @ gujma @ |
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677 |
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Torgashin, M. Yu.; Koshelets, V. P.; Dmitriev, P. N.; Ermakov, A. B.; Filippenko, L. V.; Yagoubov, P. A. |
| Title |
Superconducting integrated receivers based on Nb-AlN-NbN circuits |
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Journal Article |
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2007 |
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IEEE Trans. Appl. Supercond. |
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17 |
Issue |
2 |
Pages |
379-382 |
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RPLAB @ s @ mix_SIR_ieee_trans_2007 |
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406 |
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Gol'tsman, G.; Minaeva, O.; Korneev, A.; Tarkhov, M.; Rubtsova, I.; Divochiy, A.; Milostnaya, I.; Chulkova, G.; Kaurova, N.; Voronov, B.; Pan, D.; Kitaygorsky, J.; Cross, A.; Pearlman, A.; Komissarov, I.; Slysz, W.; Wegrzecki, M.; Grabiec, P.; Sobolewski, R. |
| Title |
Middle-infrared to visible-light ultrafast superconducting single-photon detectors |
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Journal Article |
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2007 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
| Volume |
17 |
Issue |
2 |
Pages |
246-251 |
| Keywords |
SSPD, SNSPD |
| Abstract |
We present an overview of the state-of-the-art of NbN superconducting single-photon detectors (SSPDs). Our devices exhibit quantum efficiency (QE) of up to 30% in near-infrared wavelength and 0.4% at 5 mum, with a dark-count rate that can be as low as 10 -4 s -1 . The SSPD structures integrated with lambda/4 microcavities achieve a QE of 60% at telecommunication, 1550-nm wavelength. We have also developed a new generation of SSPDs that possess the QE of large-active-area devices, but, simultaneously, are characterized by low kinetic inductance that allows achieving short response times and the GHz-counting rate with picosecond timing jitter. The improvements presented in the SSPD development, such as fiber-coupled SSPDs, make our detectors most attractive for high-speed quantum communications and quantum computing. |
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1051-8223 |
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431 |
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Koshelets, V. P.; Ermakov, A. B.; Filippenko, L. V.; Khudchenko, A. V.; Kiselev, O. S.; Sobolev, A. S.; Torgashin, M. Y.; Yagoubov, P. A.; Hoogeveen, R. W. M.; Wild, W. |
| Title |
Superconducting integrated submillimeter receiver for TELIS |
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Journal Article |
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2007 |
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IEEE Trans. Appl. Supercond. |
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17 |
Issue |
2 |
Pages |
336-342 |
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SIR |
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1051-8223 |
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no |
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524 |
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Torgashin, Mikhail Yu.; Koshelets, Valery P.; Dmitriev, Pavel N.; Ermakov, Andrey B.; Filippenko, Lyudmila V.; Yagoubov, Pavel A. |
| Title |
Superconducting Integrated Receiver Based on Nb-AlN-NbN-Nb Circuits |
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Journal Article |
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2007 |
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IEEE Trans. Appl. Supercond. |
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17 |
Issue |
2 |
Pages |
379-382 |
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SIR |
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1051-8223 |
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525 |
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Gao, J. R.; Hajenius, M.; Yang, Z. Q.; Baselmans, J. J. A.; Khosropanah, P.; Barends, R.; Klapwijk, T. M. |
| Title |
Terahertz superconducting hot electron bolometer heterodyne receivers |
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Journal Article |
| Year |
2007 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
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| Volume |
17 |
Issue |
2 |
Pages |
252-258 |
| Keywords |
HEB, mixer, direct detection effect |
| Abstract |
We highlight the progress on NbN hot electron bolometer (HEB) mixers achieved through fruitful collaboration between SRON Netherlands Institute for Space Research and Delft University of Technology, the Netherlands. This includes the best receiver noise temperatures of 700 K at 1.63 THz using a twin-slot antenna mixer and 1050 K at 2.84 THz using a spiral antenna coupled HEB mixer. The mixers are based on thin NbN films on Si and fabricated with a new contact-process and-structure. By reducing their areas HEB mixers have shown an LO power requirement as low as 30 nW. Those small HEB mixers have demonstrated equivalent sensitivity as those with large areas provided the direct detection effect due to broadband radiation is removed. To manifest that a HEB based heterodyne receiver can in practice be used at arbitrary frequencies above 2 THz, we demonstrate a 2.8 THz receiver using a THz quantum cascade laser (QCL) as local oscillator. |
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1051-8223 |
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RPLAB @ asmirn @ |
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557 |
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Yang, J. K. W.; Kerman, A. J.; Dauler, E. A.; Anant, V.; Rosfjord, K. M.; Berggren, K. K. |
| Title |
Modeling the electrical and thermal response of superconducting nanowire single-photon detectors |
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Journal Article |
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2007 |
Publication |
IEEE Trans. Appl. Supercond. |
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17 |
Issue |
2 |
Pages |
581 - 585 |
| Keywords |
SSPD, modeling |
| Abstract |
We modeled the response of superconducting nanowire single-photon detectors during a photodetection event, taking into consideration only the thermal and electrical properties of a superconducting NbN nanowire on a sapphire substrate. Our calculations suggest that heating which occurs after the formation of a photo-induced resistive barrier is responsible for the generation of a measurable voltage pulse. We compared this numerical result with experimental data of a voltage pulse from a slow device, i.e. large kinetic inductance, and obtained a good fit. Using this electro-thermal model, we estimated the temperature rise and the resistance buildup in the nanowire, and the return current at which the nanowire becomes superconducting again. We also show that the reset time of these photodetectors can be decreased by the addition of a series resistance and provide supporting experimental data. Finally we present preliminary results on a detector latching behavior that can also be explained using the electro-thermal model. |
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625 |
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Bell, M.; Kaurova, N.; Divochiy, A.; Gol'tsman, G.; Bird, J.; Sergeev, A.; Verevkin, A. |
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On the nature of resistive transition in disordered superconducting nanowires |
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Journal Article |
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2007 |
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IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
| Volume |
17 |
Issue |
2 |
Pages |
267-270 |
| Keywords |
SSPD, SNSPD |
| Abstract |
Hot-electron single-photon counters based on long superconducting nanowires are starting to become popular in optical and infrared technologies due to their ultimately high sensitivity and very high response speed. We investigate intrinsic fluctuations in long NbN nanowires in the temperature range of 4.2 K-20 K, i.e. above and below the superconducting transition. These fluctuations are responsible for fluctuation resistivity and also determine the noise in practical devices. Measurements of the fluctuation resistivity were performed at low current densities and also in external magnetic fields up to 5 T. Above the BCS critical temperature T co the resistivity is well described by the Aslamazov-Larkin (AL) theory for two-dimensional samples. Below T co the measured resistivity is in excellent agreement with the Langer-Ambegaokar-McCumber-Halperin (LAMH) theory developed for one-dimensional superconductors. Despite that our nanowires of 100 nm width are two-dimensional with respect to the coherence length, our analysis shows that at relatively low current densities the one-dimensional LAMH mechanism based on thermally induced phase slip centers dominates over the two-dimensional mechanism related to unbinding of vortex-antivortex pairs below the Berezinskii-Kosterlitz-Thouless transition. |
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1051-8223 |
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no |
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1247 |
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Kitaygorsky, J.; Komissarov, I.; Jukna, A.; Pan, D.; Minaeva, O.; Kaurova, N.; Divochiy, A.; Korneev, A.; Tarkhov, M.; Voronov, B.; Milostnaya, I.; Gol'tsman, G.; Sobolewski, R.R. |
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Dark counts in nanostructured nbn superconducting single-photon detectors and bridges |
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Journal Article |
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2007 |
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IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
| Volume |
17 |
Issue |
2 |
Pages |
275-278 |
| Keywords |
SSPD; SNSPD |
| Abstract |
We present our studies on dark counts, observed as transient voltage pulses, in current-biased NbN superconducting single-photon detectors (SSPDs), as well as in ultrathin (~4 nm), submicrometer-width (100 to 500 nm) NbN nanobridges. The duration of these spontaneous voltage pulses varied from 250 ps to 5 ns, depending on the device geometry, with the longest pulses observed in the large kinetic-inductance SSPD structures. Dark counts were measured while the devices were completely isolated (shielded by a metallic enclosure) from the outside world, in a temperature range between 1.5 and 6 K. Evidence shows that in our two-dimensional structures the dark counts are due to the depairing of vortex-antivortex pairs caused by the applied bias current. Our results shed some light on the vortex dynamics in 2D superconductors and, from the applied point of view, on intrinsic performance of nanostructured SSPDs. |
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1051-8223 |
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1248 |
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