Commissioning and performance of the Belle II pixel detector Ye, H.; Abudinen, F.; Ackermann, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2021, Letnik:
987
Journal Article
Recenzirano
The Belle II experiment at the SuperKEKB energy-asymmetric e+e− collider has completed a series of substantial upgrades and started collecting data in 2019. The experiment is expected to accumulate a ...data set of 50 ab−1 to explore new physics beyond the Standard Model at the intensity frontier. The pixel detector (PXD) of Belle II plays a key role in vertex determination. It has been developed using the DEpleted P-channel Field Effect Transistor (DEPFET) technology, which combines low power consumption in the active pixel area and low intrinsic noise with a very small material budget. In this paper, commissioning and performance of the PXD measured with first collision data are presented.
Operational experience of the Belle II pixel detector Wang, B.; Abudinen, F.; Ackermann, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2022, Letnik:
1032
Journal Article
Recenzirano
The Belle II experiment at the SuperKEKB accelerator has started its physics data taking with the full detector setup in March 2019. It aims to collect 40 times more e+e− collision data compared with ...its predecessor Belle experiment. The Belle II pixel detector (PXD) is based on the Depleted P-channel Field Effect Transistor (DEPFET) technology. The PXD plays an important role in the tracking and vertexing of the Belle II detector. Its two layers are arranged at radii of 14 mm and 22 mm around the interaction point. The sensors are thinned down to 75 μm to minimize multiple scattering, and each module has interconnects and ASICs integrated on the sensor with silicon frames for mechanical support. PXD showed good performance during data taking. It also faces several operational challenges due to the high background level from the SuperKEKB accelerator, such as the damage from beam loss events, the drift in the HV working point due to radiation effect, and the impact of the high background.
Belle II pixel detector: Performance of final DEPFET modules Paschen, B.; Abudinen, F.; Ahlburg, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2020, Letnik:
958
Journal Article
Recenzirano
A DEpleted P-channel Field Effect Transistor (DEPFET) based pixel detector was developed for the Belle II VerteX Detector (VXD). It is designed to achieve a good impact parameter resolution better ...than 15μm at the very high luminosity conditions of this experiment. In the first half of 2018 four final production modules have been deployed in the commissioning run of the detector and their performance is discussed.
•Four final type Belle II pixel detector modules operated during Belle II phase 2.•Continuous adjustments of field effect transistor gate voltages due to radiation.•Stable performance with hit efficiencies ¿ 97%.
DEPFET pixel detector in the Belle II experiment Abudinen, F.; Ackermann, K.; Albalawi, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Letnik:
936
Journal Article
Recenzirano
The Belle II experiment will run with a reduced beam asymmetry and a factor of 40 higher instantaneous luminosity compared to the Belle experiment. To cope with this and to be able to perform high ...precision vertex measurements for charge conjugation parity violating processes, a pixel detector based on DEPFET technology will be installed in the center of Belle II. Its basic properties and the DAQ chain are presented in this article.
•The Belle II experiment will achieve a 40 times higher luminosity compared to Belle.•To study CP violating processes, Belle II is equipped with a pixel detector.•The pixel detector is based on DEPFET technology with a read out frequency of 30 kHz.•Online data reduction is performed by removing background hits during DAQ.•The goal is a data reduction by a factor of ten for full luminosity.
The Belle II vertex detector integration Kodyš, P.; Abudinen, F.; Ahlburg, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Letnik:
936
Journal Article
Recenzirano
Odprti dostop
The Belle II experiment comes with a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric e+e− collider with energies tuned to ϒ(4S) resonance s=10.588 GeV. ...The accelerator has successfully completed the first phase of commissioning in 2016 and the first electron–positron collisions in Belle II took place in April 2018. Belle II features a newly designed silicon vertex detector based on DEPFET pixel and double-sided strip layers. Currently, a subset of the vertex detector is installed (Phase 2 of the experiment). Installation of the full detector (Phase 3) will be completed by the end of 2018.
This paper describes the Phase 2 arrangement of the Belle II silicon vertex detector, with focus on the interconnection of detectors and their integration with the software framework of Belle II. Alignment issues are discussed based on detector simulations and first acquired data.
Bacillus subtilis competent cells were transfected with SPP1 heteroduplices having pyrimidine dimers in one of the strands. The data obtained reveal that excision repair of the pyrimidine dimers ...influences the ratio of wild type versus mutant progeny observed in "normal" heteroduplex transfection. With increased exposure of one strand to UV dose the percentage of infective centers having the unirradiated strand genotype shows an increase. A comparison of the transfection data in her+ and her- host excludes asymmetric replication as the cause of the observed changes in the conversion pattern. The data can be explained on the basis of a dimer induced co-excision of the mismatched region. In addition transfection data from wild type/deletion mutant heteroduplices where the strand of mutant origin was irradiated exclude the possibility of the wild type loop being excised during uptake.
Nearly all demersal teleost marine fishes have pelagic larval stages lasting from several days to several weeks, during which time they are subject to dispersal. Fish larvae have considerable ...swimming abilities, and swim in an oriented manner in the sea. Thus, they can influence their dispersal and thereby, the connectivity of their populations. However, the sensory cues marine fish larvae use for orientation in the pelagic environment remain unclear. We review current understanding of these cues and how sensory abilities of larvae develop and are used to achieve orientation with particular emphasis on coral-reef fishes. The use of sound is best understood; it travels well underwater with little attenuation, and is current-independent but location-dependent, so species that primarily utilize sound for orientation will have location-dependent orientation. Larvae of many species and families can hear over a range of ∼100–1000 Hz, and can distinguish among sounds. They can localize sources of sounds, but the means by which they do so is unclear. Larvae can hear during much of their pelagic larval phase, and ontogenetically, hearing sensitivity, and frequency range improve dramatically. Species differ in sensitivity to sound and in the rate of improvement in hearing during ontogeny. Due to large differences among-species within families, no significant differences in hearing sensitivity among families have been identified. Thus, distances over which larvae can detect a given sound vary among species and greatly increase ontogenetically. Olfactory cues are current-dependent and location-dependent, so species that primarily utilize olfactory cues will have location-dependent orientation, but must be able to swim upstream to locate sources of odor. Larvae can detect odors (e.g., predators, conspecifics), during most of their pelagic phase, and at least on small scales, can localize sources of odors in shallow water, although whether they can do this in pelagic environments is unknown. Little is known of the ontogeny of olfactory ability or the range over which larvae can localize sources of odors. Imprinting on an odor has been shown in one species of reef-fish. Celestial cues are current- and location-independent, so species that primarily utilize them will have location-independent orientation that can apply over broad scales. Use of sun compass or polarized light for orientation by fish larvae is implied by some behaviors, but has not been proven. Use of neither magnetic fields nor direction of waves for orientation has been shown in marine fish larvae. We highlight research priorities in this area.
Larval coral-reef fishes have good orientation abilities. Through-water orientation of larvae in some species is location-dependent at meso-scales <10s of km, whereas other species have ...location-independent orientation at meso-scales. In situ observation of the damselfish Chromis atripectoralis showed that settlement-stage larvae swam in a southerly direction (mean = 175 ± 11°) at 100 to 1000 m from shore, both east and west of Lizard Island, northern Great Barrier Reef (NGBR), in 10 datasets from 1998 to 2008. Wind direction did not directly influence through-water swimming direction at NGBR. During 2014, in situ diver observation tested if orientation of C. atripectoralis differed regionally in the central Great Barrier Reef (CGBR), 620 km south of NGBR, and in the New Caledonia reef lagoon (NCRL), 1950 km east of CGBR. In all 3 regions, >90% of larvae swam directionally with similar precision and speeds, and with significant among-individual orientation. Yet through-water orientation was easterly at CGBR (72 ± 30°) and NCRL (87 ± 20°), and significantly different from NGBR. Over-bottom orientation (i.e. the result of current and larval swimming), measured by GPS at start and end of observing each larva, was weak east-southeasterly at NGBR (116 ± 40°, p = 0.045), not significantly directional at CGBR, and strongly westerly at NCRL (246 ± 28°, p = 0.0006), indicating that dispersal of C. atripectoralis is both current- and behaviour-dependent. This is the first report of location-dependent larval fish orientation at a regional scale. This might be an evolutionary response to regional hydrodynamic conditions to limit downstream dispersal.
Understanding larval dispersal requires knowledge of whether larvae in situ have orientated swimming, and how this varies temporally and spatially. Orientation of >300 settlement-stage larvae of ...Chromis atripectoralis (Pomacentridae) measured over 1998–2008 by divers near Lizard Island, Great Barrier Reef was consistent. All 10 data sets had southerly orientation at all locations; 94% of larvae swam directionally. Median bearings east and west of Lizard Island were 166° and 170°, respectively. Orientation precision was significantly higher under sunny than cloudy skies. Similar mean bearings were obtained in 2008 with more than 125 larvae observed in a drifting in situ chamber (DISC). Orientation varied with time of day. In sunny conditions, precision was weakly, significantly correlated with time of day, but not solar elevation; however, a greater proportion of larvae was significantly directional at low (<50°) than at high (>50°) solar elevation. Mean bearing and time of day were weakly, but significantly correlated. Bearings changed from SE during most of the day to SSW in the late afternoon, with distribution of bearings significantly different. Location-independent but diurnally-dependent orientation implies that larvae used celestial cues for orientation. Of 91 Pomacentrus lepidogenys larvae that were followed by divers, 89% swam directionally, but orientation differed among locations and years. DISC results with 20 larvae were similar. The similarity of orientation returned by different methods used on 2 fish species corroborates previous results using diver following. Both methods are useful for the study of larval-fish orientation in situ: each has advantages and limitations, and their use is complementary.
Patients with chemotherapy-refractory chronic lymphocytic leukemia (CLL) have a short life expectancy. The aim of this study was to analyze the outcome of patients with advanced CLL when treated with ...nonmyeloablative conditioning and hematopoietic cell transplantation (HCT).
Sixty-four patients diagnosed with advanced CLL were treated with nonmyeloablative conditioning (2 Gy total-body irradiation with n = 53 or without n = 11 fludarabine) and HCT from related (n = 44) or unrelated (n = 20) donors. An adapted form of the Charlson comorbidity index was used to assess pretransplantation comorbidities.
Sixty-one of 64 patients had sustained engraftment, whereas three patients rejected their grafts. The incidences of grades 2, 3, and 4 acute and chronic graft-versus-host disease were 39%, 14%, 2%, and 50%, respectively. Three patients who underwent transplantation in complete remission (CR) remained in CR. The overall response rate among 61 patients with measurable disease was 67% (50% CR), whereas 5% had stable disease. All patients with morphologic CR who were tested by polymerase chain reaction (n = 11) achieved negative molecular results, and one of these patients subsequently experienced disease relapse. The 2-year incidence of relapse/progression was 26%, whereas the 2-year relapse and nonrelapse mortalities were 18% and 22%, respectively. Two-year rates of overall and disease-free survivals were 60% and 52%, respectively. Unrelated HCT resulted in higher CR and lower relapse rates than related HCT, suggesting more effective graft-versus-leukemia activity.
CLL is susceptible to graft-versus-leukemia effects, and allogeneic HCT after nonmyeloablative conditioning might prolong median survival for patients with advanced CLL.
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