A single-photon sensitive ebCMOS camera: The LUSIPHER prototype Barbier, R.; Cajgfinger, T.; Calabria, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2011, Volume:
648, Issue:
1
Journal Article
Peer reviewed
Processing high-definition images with single-photon sensitivity acquired above 500 frames per second (fps) will certainly find ground-breaking applications in scientific and industrial domains such ...as nano-photonics. However, current technologies for low light imaging suffer limitations above the standard 30fps to keep providing both excellent spatial resolution and signal-over-noise. This paper presents the state of the art on a promising way to answer this challenge, the electron bombarded CMOS (ebCMOS) detector. A large-scale ultra fast single-photon tracker camera prototype produced with an industrial partner is described. The full characterization of the back-thinned CMOS sensor is presented and a method for Point Spread Function measurements is elaborated. Then the study of the ebCMOS performance is presented for two different multi-alkali cathodes, S20 and S25. Point Spread Function measurements carried out on an optical test bench are analysed to extract the PSF of the tube by deconvolution. The resolution of the tube is studied as a function of temperature, high voltage and incident wavelength. Results are discussed for both multi-alkali cathodes as well as a Maxwellian modelization of the radial initial energy of the photo-electrons.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
ULTIMATE is a reticle size CMOS Pixel Sensor (CPS) designed to meet the requirements of the STAR pixel detector (PXL). It includes a pixel array of 928 rows and 960 columns with a 20.7 mu m pixel ...pitch, providing a sensitive area of similar to 3.8 cm super(2). Based on the sensor designed for the EUDET beam telescope, the device is a binary output sensor with integrated zero suppression circuitry featuring a 320Mbps data throughput capability. It was fabricated in a 0.35 mu m OPTO process early in 2011. The design and preliminary test results, including charged particle detection performances measured at the CERN-SPS, are presented.
CONTEXT The need for lung protection is universally accepted, but the optimal level of positive end-expiratory pressure (PEEP) in patients with acute lung injury (ALI) or acute respiratory distress ...syndrome remains debated. OBJECTIVE To compare the effect on outcome of a strategy for setting PEEP aimed at increasing alveolar recruitment while limiting hyperinflation to one aimed at minimizing alveolar distension in patients with ALI. DESIGN, SETTING, AND PATIENTS A multicenter randomized controlled trial of 767 adults (mean SD age, 59.9 15.4 years) with ALI conducted in 37 intensive care units in France from September 2002 to December 2005. INTERVENTION Tidal volume was set at 6 mL/kg of predicted body weight in both strategies. Patients were randomly assigned to a moderate PEEP strategy (5-9 cm H2O) (minimal distension strategy; n = 382)
or to a level of PEEP set to reach a plateau pressure of 28 to 30
cm H2O (increased recruitment strategy; n = 385). MAIN OUTCOME MEASURES The primary end point was mortality at 28 days. Secondary end points were hospital mortality at 60 days, ventilator-free days, and organ failure–free days at 28 days. RESULTS The 28-day mortality rate in the minimal distension group was 31.2% (n = 119) vs 27.8% (n = 107) in the increased recruitment group (relative risk, 1.12 95% confidence interval, 0.90-1.40; P = .31). The hospital mortality rate in the minimal distension group was 39.0% (n = 149) vs 35.4%
(n = 136) in the increased recruitment group (relative risk,
1.10 95% confidence interval, 0.92-1.32; P = .30). The increased recruitment group compared with the minimal distension group had a higher median number of ventilator-free days (7 interquartile range {IQR}, 0-19 vs 3 IQR, 0-17; P = .04) and organ failure–free days (6 IQR, 0-18 vs 2 IQR, 0-16; P = .04).
This strategy also was associated with higher compliance values, better oxygenation, less use of adjunctive therapies, and larger fluid requirements. CONCLUSIONS A strategy for setting PEEP aimed at increasing alveolar recruitment while limiting hyperinflation did not significantly reduce mortality.
However, it did improve lung function and reduced the duration of mechanical ventilation and the duration of organ failure. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00188058
The PLUME (Pixelated Ladder with Ultra-Low Material Embedding) Collaboration is developing ultra-light ladders for the vertex detector for a future linear collider. The double-sided ladder will ...integrate the sensors, readout infrastructure and mechanical supports with the aim of total material budget of 0.3% of radiation length. The requirement of as light as possible construction is driven by physics, in particular by measurements requiring determination of the quark charge sign. The first prototype ladders were prepared and tested in the beam. The alignment issues for the ladders will be tested within the AIDA (Advanced European Infrastructures for Detectors at Accelerators) EU FP7 project.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Due to their low noise, CMOS Monolithic Active Pixel Sensors are suited to sense X-rays with a few keV quantum energy, which is of interest for high resolution X-ray imaging. Moreover, the good ...energy resolution of the silicon sensors might be used to measure this quantum energy. Combining both features with the good spatial resolution of CMOS sensors opens the potential to build "color sensitive" X-ray cameras. Taking such colored images is hampered by the need to operate the CMOS sensors in a single photon counting mode, which restricts the photon flux capability of the sensors. More importantly, the charge sharing between the pixels smears the potentially good energy resolution of the sensors. Based on our experience with CMOS sensors for charged particle tracking, we studied techniques to overcome the latter by means of an offline processing of the data obtained from a CMOS sensor prototype. We found that the energy resolution of the pixels can be recovered at the expense of reduced quantum efficiency. We will introduce the results of our study and discuss the feasibility of taking colored X-ray pictures with CMOS sensors.
Improved radiation tolerance of MAPS using a depleted epitaxial layer Dorokhov, A.; Bertolone, G.; Baudot, J. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2010, Volume:
624, Issue:
2
Journal Article
Peer reviewed
Tracking performance of Monolithic Active Pixel Sensors (MAPS) developed at IPHC (Turchetta, et al., 2001)
1 have been extensively studied (Winter, et al., 2001; Gornushkin, et al., 2002)
2,3. ...Numerous sensor prototypes, called MIMOSA,
1
1
Standing for Minimum Ionising particle MOS Active pixel sensors.
were fabricated and tested since 1999 in order to optimise the charge collection efficiency and power dissipation, to minimise the noise and to increase the readout speed.
The radiation tolerance was also investigated. The highest fluence tolerable for a
10
μ
m
pitch device was found to be
∼
10
13
n
eq
/
cm
2
, while it was only
2
×
10
12
n
eq
/
cm
2
for a
20
μ
m
pitch device. The purpose of this paper is to show that the tolerance to non-ionising radiation may be extended up to
O(10
14) n
eq/cm
2. This goal relies on a fabrication process featuring a
15
μ
m
thin, high resistivity (
∼
1
k
Ω
cm
) epitaxial layer. A sensor prototype (MIMOSA-25) was fabricated in this process to explore its detection performance. The depletion depth of the epitaxial layer at standard CMOS voltages (
<
5
V
) is similar to the layer thickness. Measurements with m.i.p.s
2
2
Standing for minimum ionising particle.
show that the charge collected in the seed pixel is at least twice larger for the depleted epitaxial layer than for the undepleted one, translating into a signal-to-noise ratio (SNR) of
∼
50
. Tests after irradiation have shown that this excellent performance is maintained up to the highest fluence considered (
3
×
10
13
n
eq
/
cm
2
)
, making evidence of a significant extension of the radiation tolerance limits of MAPS.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Preclinical behavior neuroimaging gathers simultaneous assessment of behavior and functional brain imaging. It is a potential key breakthrough to improve the understanding of brain processes and ...assess the validity of preclinical studies in drug development. Achieving such a combination is difficult, anesthesia or restraints inherent to conventional nuclear imaging preclude its use for behavior studies. In that context, we have proposed an original strategy using submillimetric probes to directly measures positrons inside the rat brain. This paper gives the results of Monte Carlo simulations of a new generation of intracerebral positron probe based on a complementary metal oxide semi-conductor monolithic active pixel sensor. We present the results obtained for a probe into a large homogeneous volume of radioactive water ( 18 F) leading to a sensitivity of 0.88 cps<inline-formula> <tex-math notation="LaTeX">{\cdot } </tex-math></inline-formula>Bq<inline-formula> <tex-math notation="LaTeX">^{ {-1}} {\cdot } </tex-math></inline-formula>mm 3 and a mean energy deposition by positrons of 15.1 keV. Simulation in simplified brain-shaped sources modeling a 11 C-raclopride experiment shows that the implanted volume modeling the left putamen contribute to 92.4% of the signal from positrons. We also investigate the effects of the thickness of the sensitive layer, the energy threshold and pixel dimensions on the detection capacities of the sensor. We demonstrate that an increase in the sensitive thickness from 18 to 190 <inline-formula> <tex-math notation="LaTeX"> \mu \text{m} </tex-math></inline-formula> would lead to an increase of positrons sensitivity by a factor of 1.74, but to a decrease of the direct (positrons) to indirect (<inline-formula> <tex-math notation="LaTeX"> \gamma </tex-math></inline-formula>-rays and electrons) sensitivity ratio by a factor of 1.59. Finally, we show that for a threshold lower than about 5 keV the effect of the pixel dimensions is negligible.
CMOS Monolithic Active Pixel Sensors (MAPS) have demonstrated excellent performance as tracking detectors for charged particles. They provide an outstanding spatial resolution (a few mu m), a ...detection efficiency of gap 99.9%, very low material budget (0.05% X sub(0)) and good radiation tolerance (gap 1 Mrad, gap 10 super(14) n sub(eq)/cm super(2)) 1. This recommends them as an interesting technology for various applications in heavy ion and particle physics. For the vertex detectors of CBM and ALICE, we are aiming at developing large scale sensors with an integration time of 30 mu s. Reaching this goal is eased by features available in CMOS-processes with 0.18 pm feature size. To exploit this option, some sensor designs have been migrated from the previously used 0.35 mu m processes to this novel process. We report about our first findings with the devices obtained with a focus on noise and the tolerance to ionizing radiation.
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