93 research outputs found
4-Dimensional Tracking with Ultra-Fast Silicon Detectors
The evolution of particle detectors has always pushed the technological limit
in order to provide enabling technologies to researchers in all fields of
science. One archetypal example is the evolution of silicon detectors, from a
system with a few channels 30 years ago, to the tens of millions of independent
pixels currently used to track charged particles in all major particle physics
experiments. Nowadays, silicon detectors are ubiquitous not only in research
laboratories but in almost every high-tech apparatus, from portable phones to
hospitals. In this contribution, we present a new direction in the evolution of
silicon detectors for charge particle tracking, namely the inclusion of very
accurate timing information. This enhancement of the present silicon detector
paradigm is enabled by the inclusion of controlled low gain in the detector
response, therefore increasing the detector output signal sufficiently to make
timing measurement possible. After providing a short overview of the advantage
of this new technology, we present the necessary conditions that need to be met
for both sensor and readout electronics in order to achieve 4-dimensional
tracking. In the last section we present the experimental results,
demonstrating the validity of our research path.Comment: 72 pages, 3 tables, 55 figure
Comparing radiation tolerant materials and devices for ultra rad-hard tracking detectors
The need for ultra-radiation hard semiconductor detectors for the inner tracker regions in high energy physics experiments of the future generation can be satisfied either with materials which are inherently more radiation hard than float zone silicon or with special detector structures with improved radiation resistance. This report compares directly the data on the performance of rad-hard materials and devices proposed for the superLHC
4D tracking with ultra-fast silicon detectors
The evolution of particle detectors has always pushed the technological limit in order to provide enabling technologies to researchers in all fields of science. One archetypal example is the evolution of silicon detectors, from a system with a few channels 30 years ago, to the tens of millions of independent pixels currently used to track charged particles in all major particle physics experiments. Nowadays, silicon detectors are ubiquitous not only in research laboratories but in almost every high-tech apparatus, from portable phones to hospitals. In this contribution, we present a new direction in the evolution of silicon detectors for charge particle tracking, namely the inclusion of very accurate timing information. This enhancement of the present silicon detector paradigm is enabled by the inclusion of controlled low gain in the detector response, therefore increasing the detector output signal sufficiently to make timing measurement possible. After providing a short overview of the advantage of this new technology, we present the necessary conditions that need to be met for both sensor and readout electronics in order to achieve 4D tracking. In the last section, we present the experimental results, demonstrating the validity of our research path
Charge collection measurements with p-type Magnetic Czochralski silicon single pad detectors
Abstract The charge collected from beta source particles in single pad detectors produced on p-type Magnetic Czochralski (MCz) silicon wafers has been measured before and after irradiation with 26 MeV protons. After a 1 MeV neutron equivalent fluence of 1 × 10 15 cm - 2 the collected charge is reduced to 77% at bias voltages below 900 V. This result is compared with previous results from charge collection measurements
Ultra-fast silicon detectors
Abstract We propose to develop a fast, thin silicon sensor with gain capable to concurrently measure with high precision the space (∼10 μm) and time (∼10 ps) coordinates of a particle. This will open up new application of silicon detector systems in many fields. Our analysis of detector properties indicates that it is possible to improve the timing characteristics of silicon-based tracking sensors, which already have sufficient position resolution, to achieve four-dimensional high-precision measurements. The basic sensor characteristics and the expected performance are listed, the wide field of applications are mentioned and the required R&D topics are discussed
Charge collection and capacitance–voltage analysis in irradiated n-type magnetic Czochralski silicon detectors
Abstract The depletion depth of irradiated n-type silicon microstrip detectors can be inferred from both the reciprocal capacitance and from the amount of collected charge. Capacitance voltage ( C – V ) measurements at different frequencies and temperatures are being compared with the bias voltage dependence of the charge collection on an irradiated n-type magnetic Czochralski silicon detector. Good agreement between the reciprocal capacitance and the median collected charge is found when the frequency of the C – V measurement is selected such that it scales with the temperature dependence of the leakage current. Measuring C – V characteristics at prescribed combinations of temperature and frequency allows then a realistic estimate of the depletion characteristics of irradiated silicon strip detectors based on C – V data alone
Measurements with Irradiated 3D Silicon Strip Detectors
For the unprecedentedly high radiation level at the sLHC, the luminosity upgrade of the LHC, new tracking detectors are investigated. Among different approaches, silicon detectors in 3D technology constitute a promising option. Columnar electrodes are etched into the substrate, therefore the distance for charge collection and depletion is decoupled from the detector thickness. Thus, two of the detrimental effects caused by radiation in silicon (increased depletion voltage and charge carrier trapping) can be reduced. Results of measurements with irradiated 3D silicon strip detectors produced by IMB-CNM are presented
A population of gamma-ray emitting globular clusters seen with the Fermi Large Area Telescope
Globular clusters with their large populations of millisecond pulsars (MSPs)
are believed to be potential emitters of high-energy gamma-ray emission. Our
goal is to constrain the millisecond pulsar populations in globular clusters
from analysis of gamma-ray observations. We use 546 days of continuous
sky-survey observations obtained with the Large Area Telescope aboard the Fermi
Gamma-ray Space Telescope to study the gamma-ray emission towards 13 globular
clusters. Steady point-like high-energy gamma-ray emission has been
significantly detected towards 8 globular clusters. Five of them (47 Tucanae,
Omega Cen, NGC 6388, Terzan 5, and M 28) show hard spectral power indices and clear evidence for an exponential cut-off in the range
1.0-2.6 GeV, which is the characteristic signature of magnetospheric emission
from MSPs. Three of them (M 62, NGC 6440 and NGC 6652) also show hard spectral
indices , however the presence of an exponential cut-off
can not be unambiguously established. Three of them (Omega Cen, NGC 6388, NGC
6652) have no known radio or X-ray MSPs yet still exhibit MSP spectral
properties. From the observed gamma-ray luminosities, we estimate the total
number of MSPs that is expected to be present in these globular clusters. We
show that our estimates of the MSP population correlate with the stellar
encounter rate and we estimate 2600-4700 MSPs in Galactic globular clusters,
commensurate with previous estimates. The observation of high-energy gamma-ray
emission from a globular cluster thus provides a reliable independent method to
assess their millisecond pulsar populations that can be used to make
constraints on the original neutron star X-ray binary population, essential for
understanding the importance of binary systems in slowing the inevitable core
collapse of globular clusters.Comment: Accepted for publication in A&A. Corresponding authors: J.
Kn\"odlseder, N. Webb, B. Pancraz
- …