This paper focuses on the understanding of the Random Telegraph Signal (RTS) in Single-Photon Avalanche Diodes (SPAD). We studied the RTS of two different SPAD layouts, designed and implemented in a ...150-nm CMOS process, after proton irradiation. The two structures are characterized by different junction types: the first structure is constituted by a P+/Nwell junction, while the second is formed by a Pwell/Niso junction. RTS occurrence has been measured in about one thousand SPAD pixels and the differences addressed in two layouts are motivated and discussed. Hypotheses on the RTS origin are drawn by analyzing the RTS time constants and the RTS occurrence evolution as a function of the annealing temperature.
Proton irradiation effects on a Single-Photon Avalanche Diodes (SPADs) device manufactured using a 150-nm CMOS process are presented. An irradiation campaign has been carried out with protons of 20 ...MeV and 24 MeV on several samples of a test chip containing SPADs arrays with two different junction layouts. The dark count rate distributions have been analyzed as a function of the displacement damage dose. Annealing and cooling have been investigated as possible damage mitigation approaches. We also discuss, through a space radiation simulation, the suitability of such devices on several space mission case-studies.
•Arsenic effects on nitrification were revealed using FBR enriched cultures.•Nitrification was not affected by 100mg AsTOT/L at neutral pH.•150–200mg AsTOT/L inhibited ammonium oxidation by ...25%.•As(III) oxidation to As(V) decreased arsenic toxicity to nitrification.•FBR enrichment consisted of C. Nitrospira defluvii and other nitrifying species.
Mining and mineral processing of gold-bearing ores often release arsenic to the environment. Ammonium is released when N-based explosives or cyanide are used. Nitrification of simulated As-rich mining waters was investigated in batch bioassays using nitrifying cultures enriched in a fluidized-bed reactor (FBR). Nitrification was maintained at 100mg AsTOT/L. In batch assays, ammonium was totally oxidized by the FBR enrichment in 48h. As(III) oxidation to As(V) occurred during the first 3h attenuating arsenic toxicity to nitrification. At 150 and 200mg AsTOT/L, nitrification was inhibited by 25%. Candidatus Nitrospira defluvii and other nitrifying species mainly colonized the FBR. In conclusion, the FBR enriched cultures of municipal activated sludge origins tolerated high As concentrations making nitrification a potent process for mining water treatment.
The dispersion of nitrogenous compounds and heavy metals into the environment is frequent during mining activities. The effects of nickel (Ni) and cobalt (Co) on denitrification of simulated mine ...waters were investigated in batch bioassays and fluidized-bed reactors (FBRs). At pH 7, batch tests revealed that Co did not exhibit inhibition on denitrification even at 86.6 mg/L. Ni showed to be inhibitory at 50 and 100 mg/L by decreasing nitrate removal efficiencies of 18 and 65 %, respectively. In two FBRs, operated at 7–8 and 22 °C, 5.5 mg/L Ni did not affect nitrate and nitrite removals because of FBR potential of diluting soluble Ni feed concentration. On the contrary, the effluent pH clearly decreased in both FBR1 and FBR2 because of nickel sulfide precipitation and Ni inhibition of the last two steps of denitrification. When Ni injection was stopped, the process recovered more slowly at 22 than 7–8 °C. This is the first study reporting the effect of Ni on denitrification in biological FBRs.
Inferior vena cava (IVC) filters are used to prevent fatal and nonfatal pulmonary embolism in patients who otherwise cannot receive anticoagulation for venous thrombosis. While generally safe and ...effective, complications can arise, especially after prolonged implantation. Timely retrieval is essential once the indication for insertion has resolved. However, encountering patients with long-standing embedded filters is not uncommon. This case report discusses the successful retrieval of a permanent Greenfield IVC filter after 29 years.
CMOS Single-Photon Avalanche Diodes (SPADs) have been introduced recently in many scientific applications. This paper reports on the performance, in terms of Dark Count Rate (DCR), of a photo-sensor ...based on CMOS SPADs. The device has been subjected to an accurate investigation, in order to evaluate its behaviour in a radiation environment. Several irradiation tests were conducted, and a complete survey of their effects on the DCR behaviour has been performed. An overall increase in the DCR level has been measured, meaning that new defects have been introduced in the space charge region of the SPADs. Furthermore, for a fraction of the SPADs, DCR measurements show a Random Telegraph Signal (RTS) temporal pattern.
Development of a new 2-inch hybrid photo-detector using MPPC Fukasawa, A.; Hotta, Y.; Ishizu, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2018, Letnik:
912
Journal Article
Recenzirano
We have newly developed a Hybrid Photo-Detector (HPD) with 2-inch diameter. It consists of a bialkali photocathode and a 3 mm x 3 mm Multi-Pixel-Photon Counter (MPPC) sealed in a glass tube. The ...electric field inside the tube is designed so that photoelectrons emitted from the photocathode are collected in the MPPC, where photoelectrons are amplified. For conventional HPDs with an avalanche diode, extremely high voltage such as -8kV has to be provided to achieve gain sufficient for single photon detection. However, our HPD with MPPC has single photon sensitivity only with lower voltage like PMTs due to high gain of MPPC. In addition, this device can cover larger area with only one MPPC. These features enable us to easily handle high performance HPD in various applications, such as high energy physics, biomedical field etc. This test sample was produced in 2016, and we have checked its basic characteristics. The peak photocathode quantum efficiency was found to be very high of 37% at the wavelength of 340 nm. We have confirmed that HPD with MPPC has capability of single photon detection in low operation voltage less than -2 kV. This report will present detailed performance studies of this sample.
•A HPD with 2-inch diameter has been developed.•The peak photocathode quantum efficiency was found to be very high.•Capability of single photon detection in -1.5kV operation was confirmed.
A
bstract
We report a new measurement of the
e
+
e
−
→
ϒ(
nS
)
π
+
π
−
(
n
= 1
,
2
,
3) cross sections at energies from 10
.
52 to 11
.
02 GeV using data collected with the Belle detector at the KEKB ...asymmetric-energy
e
+
e
−
collider. We observe a new structure in the energy dependence of the cross sections; if described by a Breit-Wigner function its mass and width are found to be
M
=
10752.7
±
5.9
−
1.1
+
0.7
MeV
/
c
2
and
Γ
=
35.5
−
11.3
−
3.3
+
17.6
+
3.9
MeV, where the first error is statistical and the second is systematic. The global significance of the new structure including systematic uncertainty is 5.2 standard deviations. We also find evidence for the
e
+
e
−
→
ϒ (1
S
)
π
+
π
−
process at the energy 10
.
52 GeV, which is below the
B
B
¯
threshold.
A
bstract
We measure the branching fractions and
CP
asymmetries for the singly Cabibbo-suppressed decays
D
0
→
π
+
π
−
η
,
D
0
→
K
+
K
−
η
, and
D
0
→
ϕη
, using 980 fb
−
1
of data from the Belle ...experiment at the KEKB
e
+
e
−
collider. We obtain
B
D
0
→
π
+
π
−
η
=
1.22
±
0.02
stat
±
0.02
syst
±
0.03
B
ref
×
10
−
3
,
B
D
0
→
K
+
K
−
η
=
1.80
−
0.06
+
0.07
stat
±
0.04
syst
±
0.05
B
ref
×
10
−
4
,
B
D
0
→
ϕη
=
1.84
±
0.09
stat
±
0.06
syst
±
0.05
B
ref
×
10
−
4
,
where the third uncertainty (
B
ref
) is from the uncertainty in the branching fraction of the reference mode
D
0
→
K
−
π
+
η
. The color-suppressed decay
D
0
→
ϕη
is observed for the first time, with very high significance. The results for the
CP
asymmetries are
A
CP
D
0
π
+
π
−
η
=
0.9
±
1.2
stat
±
0.5
syst
%
,
A
CP
D
0
→
K
+
K
−
η
=
−
1.4
±
3.3
stat
±
1.1
syst
%
,
ACP
D
0
→
ϕη
=
−
1.9
±
4.4
stat
±
0.6
syst
%
.
The results for
D
0
→
π
+
π
−
η
are a significant improvement over previous results. The branching fraction and
A
CP
results for
D
0
→
K
+
K
−
η
, and the
ACP
result for
D
0
→
ϕη
, are the first such measurements. No evidence for
CP
violation is found in any of these decays.
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