Abstract
ALTIROC2 is a 225-channel ASIC designed in CMOS 130 nm to read out a 15 × 15 matrix of 1.3 mm × 1.3 mm Low Gain Avalanche Diodes (LGAD) for the ATLAS HGTD (High Granularity Timing Detector). ...The targeted combined time resolution of the sensor and its readout electronics range from 35 ps/hit (initial) to 65 ps/hit (end of operational lifetime). Each ASIC channel integrates a high-speed preamplifier followed by a high speed discriminator and two TDCs for Time-of-Arrival and Time-Over-Threshold measurements as well as a local memory. This front-end must exhibit a small jitter while keeping a challenging power consumption of less than 4.5 mW per channel. This conference proceeding summarizes the ASIC architecture, its measured performances compared to simulation, along with the requirements for the ATLAS HGTD experiments.
Abstract
A high-resolution clock phase shifter is implemented to adjust the phase of multiple clocks at 40 MHz, 80 MHz, or 640 MHz in the ALTIROC chip. The phase shifter has a coarse-phase shifter ...and a fine-phase shifter to achieve a step size of 97.7 ps and an adjustable range of 25 ns. The fine delay unit is based on a Delay Locked Loop (DLL) operating at 640 MHz. The phase shifter is fabricated in a 130 nm CMOS process. The area of the phase shifter is 725 µm × 248 µm. The Differential Non-Linearity (DNL) and the Integral Non-Linearity (INL) are ±0.6 LSB and ±0.75 LSB, respectively. The jitter from −25 °C to 20 °C is less than 15.5 ps (RMS), including the contributions from the FPGA clock source and the PLL. The power consumption is 11.2 mW.
Abstract
In the past years, it has been observed at several beam test campaigns that
irradiated LGAD sensors break with a typical star shaped burn mark when
operated at voltages much lower than those ...at which they were safely operated
during laboratory tests. The study presented in this paper was designed to
determine the safe operating voltage that these sensors can withstand. Many
irradiated sensors from various producers were tested in two test beam
facilities, DESY (Hamburg) and CERN-SPS (Geneva), as part of ATLAS High
Granularity Timing Detector (HGTD) beam tests. The samples were placed in the
beam and kept under bias over a long period of time in order to reach a high
number of particles crossing each sensor. Both beam tests lead to a similar
conclusion, that these destructive events begin to occur when the average
electric field in the sensor becomes larger than
12 V/μm.
Abstract
The development of detectors that provide high resolution in four dimensions has attracted wide-spread interest in the scientific community for applications in high-energy physics, nuclear ...physics, medical imaging, mass spectroscopy as well as quantum information. However, finding a technology capable of fulfilling such aspiration proved to be an arduous task.
Among other silicon-based candidates, the Low-Gain Avalanche Diode (LGAD) has already shown excellent timing performances but proved to be unsuitable for fine pixelization. Therefore, the AC-coupled LGAD (AC-LGAD) approach was introduced to provide high resolution in both time and space, making it a promising candidate for future 4D detectors.
However, appropriate readout electronics must be developed to match the sensor's fast-time and fine-pitch capabilities. This is currently a major technological challenge.
In this paper, we test AC-LGAD prototypes read out by the fast-time ASIC ALTIROC 0, originally developed for the readout of DC-coupled LGADs for the ATLAS experiment at the High Luminosity-LHC. Signal generated by either betas from a
90
Sr source or a focused infra-red laser were analyzed. This paper details the first successful readout of an AC-LGAD sensor using a readout chip. This result will pave the way for the design and construction of a new generation of AC-LGAD-based 4D detectors.
A gas chromatography with nitrogen–phosphorus detection direct method for methoxyurea herbicide determination in powdered potato and fresh potato samples has been developed. A previous study of the ...thermal stability of the phenylurea herbicides seems to confirm that the ones containing the methoxy radical, i.e. monolinuron, linuron and chlorbromuron, were stable. The herbicides were extracted from the sample through liquid–liquid extraction with dichloromethane–light petroleum (1:1), followed by solid-phase extraction in a C
8 cartridge. The recoveries were in the range 84–95% for powdered potato and 86–101% for fresh potato. The RSD values were less than 10%, at 0.1 μg g
−1 concentration level (
n=4) for both types of samples. Detection limits of the method were 7.0–30 ng g
−1 for powdered potato and 6.0–50 ng g
−1 for fresh potato.
A prototype of gamma imaging system has been developed for the detection of fuel rod deformations, based on the WidePIX hybrid pixel detector, associated with a collimator. The WidePIX detector used ...in the frame of these developments is made of 2 × 5 Timepix devices hybridized with a 1 mm-thick cadmium telluride semiconductor. A specific collimator was designed, offering the best compromise between mechanical feasibility, cost, signal-to-noise ratio and angular resolution, and making it possible to visualize the fuel rod deformations. In this work, we present the design of the collimator carried out by Monte-Carlo simulation, and experimental results obtained with this prototype on a Cs-137 and Co-60 metrological irradiator.
Abstract
This paper presents the design and characterisation of a front-end prototype ASIC for the ATLAS High Granularity Timing Detector, which is planned for the High-Luminosity phase of the LHC.
...This prototype, called ALTIROC1, consists of a 5 × 5-pad matrix and contains the analog
part of the single-channel readout (preamplifier, discriminator, two TDCs and SRAM).
Two preamplifier architectures (transimpedance and voltage) were implemented and tested.
The ASIC was characterised both alone and as a module when connected to a 5 × 5-pad array of LGAD sensors.
In calibration measurements, the ASIC operating alone was found to satisfy the technical requirements for the project, with similar performances for both preamplifier types. In particular, the jitter was found to be 15 ± 1 ps (35 ± 1 ps) for an injected charge of 10 fC (4 fC).
A degradation in performance was observed when the ASIC was connected to the LGAD array. This is attributed to digital couplings at the entrance of the preamplifiers.
When the ASIC is connected to the LGAD array, the lowest detectable charge increased from 1.5 fC to 3.4 fC. As a consequence, the jitter increased for an injected charge of 4 fC. Despite this increase, ALTIROC1 still satisfies the maximum jitter specification (below 65 ps) for the HGTD project.
This coupling issue also affects the time over threshold measurements and the time-walk correction can only be performed with transimpedance preamplifiers.
Beam test measurements with a pion beam at CERN were also undertaken to evaluate the performance of the module. The best time resolution obtained using only ALTIROC TDC data was 46.3 ± 0.7 ps for a restricted time of arrival range where the coupling issue is minimized.
The residual time-walk contribution is equal to 23 ps and is the dominant electronic noise contribution to the time resolution at 15 fC.
The development of detectors that provide high resolution in four dimensions has attracted wide-spread interest in the scientific community for several applications in high-energy physics, nuclear ...physics, medical imaging, mass spectroscopy, as well as quantum information. The Low-Gain Avalanche Diode (LGAD) silicon detector has already shown excellent timing performances, but since fine pixelization of LGADs is difficult to achieve, the AC-coupled LGAD (AC-LGAD) approach was introduced to provide high spatial resolution. In this type of device, the signal is capacitively induced on fine-pitched electrodes placed over an insulator and is shared among multiple electrodes. AC-LGADs are therefore considered as promising candidates for future detectors to provide 4-dimensional measurements with high resolution in both space and time dimensions. AC-LGAD sensors designed and fabricated at the Brookhaven National Laboratory (USA) have been coupled and read-out using a fast-time ASIC prototype, the ATLAS LGAD Timing Integrated Read-Out Chip (ALTIROC) that was developed by Omega/IJCLab (France) for the ATLAS timing detector at the HL-LHC. The response of an AC-LGAD strip sensors to beta particles and IR photons has been measured using the ALTIROC0 ASIC and used to study signal sharing, as well as spatial and time resolution of the AC-LGAD sensor.
This study aimed to compare physical performance (countermovement jump height and throwing velocity) and psychological traits (mood state and perceived pain) across the menstrual cycle.
Eight women ...from an amateur handball team (age=19.8±1.9 years) were tested during two months at three time points of the menstrual cycle (early follicular phase, late follicular phase, and mid-luteal phase) (i.e., six testing sessions). The calendar-based and the urinary luteinizing hormone methods were used in combination to detect the phase of the menstrual cycle. Two questionnaires were administered at the beginning of each testing session to assess the mood state (Self-Assessment Manikin scale for Valence) and perceived pain (Visual Analogic Scale Pain scale) and, afterwards, the countermovement jump height and throwing velocity were evaluated.
The main results showed no significant differences between the phases of the menstrual cycle for countermovement jump height (P=0.708), throwing velocity (P=0.305), Self-Assessment Manikin scale for Valence (P=0.639) or Visual Analogic Scale Pain scale (P=0.565).
These results suggest that the performance of explosive lower-body and upper-body tasks is not affected across the menstrual cycle in young athletes whose mood and perceived pain are also unaffected by these hormonal fluctuations.
Cette étude visait à comparer les performances physiques (hauteur de saut de contre-mouvement et vitesse de projection) et les traits psychologiques (état d’humeur et douleur perçue) au cours du cycle menstruel.
Huit femmes d’une équipe de handball amateur (âge=19,8±1,9 ans) ont été testées pendant deux mois en trois moments différents du cycle menstruel (phase folliculaire précoce, phase folliculaire tardive et phase lutéale moyenne) (c’est-à-dire six séances de test). Les méthodes basées sur le calendrier et l’hormone lutéinisante urinaire ont été utilisées pour caractériser la phase du cycle menstruel. Deux questionnaires ont été administrés au début de chaque session de test afin d’évaluer l’état des émotions (échelle SAM, self-assessment Manikin) et la douleur perçue (échelle visuelle analogique de la douleur) et, par la suite, la hauteur de saut de contre-mouvement et la vitesse de tir ont été évaluées.
Les principaux résultats n’ont pas montré de différence significative entre les mesures de performance au cours du saut de contre-mouvement (p=0,708), de vitesse de tir (p=0,305), des valeurs de l’échelle de SAM (p=0,639) ou de l’échelle visuelle analogique de douleur (p=0,565) au cours des différentes phases du cycle menstruel. Ces résultats suggèrent que les performances au cours de tâches explosives du bas du corps et du haut du corps n’est pas affectée par le cycle menstruel chez les jeunes athlètes dont l’humeur et la douleur perçue ne sont pas non plus affectées par les fluctuations hormonales contemporaines du cycle menstruel.
