X‐ray free‐electron lasers (XFELs) deliver pulses of coherent X‐rays on the femtosecond time scale, with potentially high repetition rates. While XFELs provide high peak intensities, both the ...intensity and the centroid of the beam fluctuate strongly on a pulse‐to‐pulse basis, motivating high‐rate beam diagnostics that operate over a large dynamic range. The fast drift velocity, low X‐ray absorption and high radiation tolerance properties of chemical vapour deposition diamonds make these crystals a promising candidate material for developing a fast (multi‐GHz) pass‐through diagnostic for the next generation of XFELs. A new approach to the design of a diamond sensor signal path is presented, along with associated characterization studies performed in the XPP endstation of the LINAC Coherent Light Source (LCLS) at SLAC. Qualitative charge collection profiles (collected charge versus time) are presented and compared with those from a commercially available detector. Quantitative results on the charge collection efficiency and signal collection times are presented over a range of approximately four orders of magnitude in the generated electron–hole plasma density.
Two approaches to the design of a diamond sensor signal path were explored using high‐intensity X‐ray pulses from the LINAC Coherent Light Source at SLAC. Results on the charge‐collection efficiency and signal collection time are presented over a range of approximately four orders of magnitude in the generated electron–hole plasma density.
A closed-form approximate expression is presented for the short time-frame development of silicon diode sensor signals in the context of high frame-rate detection of incident X-ray fluxes, in the ...limit that the X-ray absorption profile generates a longitudinally-uniform distribution of electron-hole pairs in the detector bulk. The expression represents the immediate time development of signals from diode sensors both with (LGAD) and without (PIN) gain, and presents a temporal scale associated with the onset of gain. Principles limiting the detection frame rate in the presence of electronic readout noise are discussed. Making use of an elemental simulation, the relative advantage of LGAD vs. PIN diode sensors is explored as a function of the effective electronic collection time. It is found that for an idealized LGAD sensor with a gain of 30, the gain provided by impact ionization yields an advantage relative to PIN diode sensors for frame rates as high as 10 GHz.
Soft lithographic methods describe a set of printing methods which are widely used for the preparation of structured surfaces. Structured surfaces are essential components in the field of ...(opto-)electronic devices such as organic light emitting diodes, photovoltaics or organic field effect transistors. In recent years, crucial progress has been achieved in the development of patterned metal coatings for these applications. This review focusses on new strategies for soft lithographical printing of metal structures emphasizing the subtle interplay of printing techniques, metal precursor chemistry, and surface functionalization strategies.
Low Gain Avalanche Diodes (LGADs) are thin (20-50
μm
) silicon diode sensors with modest internal gain (typically 5 to 50) and exceptional time resolution (17
ps
to 50
ps
). However, the granularity ...of such devices is limited to the millimeter scale due to the need to include protection structures at the boundaries of the readout pads to avoid premature breakdown due to large local electric fields. Here, we present a new approach – the Deep-Junction LGAD (DJ-LGAD) – that decouples the high-field gain region from the readout plane. This approach is expected to improve the achievable LGAD granularity to the tens-of-micron scale while maintaining direct charge collection on the segmented electrodes.
Experimental Study of Acceptor Removal in UFSD Jin, Y.; Ren, H.; Christie, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2020, Letnik:
983, Številka:
C
Journal Article
Recenzirano
Odprti dostop
The performance of the Ultra-Fast Silicon Detectors (UFSD) after irradiation with neutrons and protons is compromised by the removal of acceptors in the thin layer below the junction responsible for ...the gain. This effect is tested both with capacitance–voltage, C–V, measurements of the doping concentration and with measurements of charge collection, CC, using charged particles. We find a perfect linear correlation between the bias voltage to deplete the gain layer determined with C–V and the bias voltage to collect a defined charge, measured with charge collection. An example for the usefulness of this correlation is presented.
Abstract Advances in timing detector technology require new specialized readout electronics. Applications demand below 10 ps time of arrival resolution and low power for a low repetition rate. A ...possible path to achieve O(10 ps) time resolution is an integrated chip using Silicon Germanium (SiGe) technology. Using DoE SBIR funding, Anadyne, Inc., in collaboration with UC Santa Cruz, has developed a prototype SiGe front-end readout chip optimized for low power and timing resolution. Two versions of the chip were produced with performance in simulation: a more power version with 10 ps resolution at 5 fC with 1.1 mW/channel, and a less power version with 10 ps resolution at 8 fC with 0.6 mW/channel. The chip was produced at Tower Semiconductor with 350 nm technology. The ASIC from the prototype run shows good performance: a rise time of 0.7–1 ns and 25 mV per fC response with RMS noise <1 mV. Simulation and results from the prototype will be reported in this paper.
Abstract
Low Gain Avalanche Diodes (LGADs) represent the
state-of-the-art in timing measurements and will instrument the
future Timing Detectors of ATLAS and CMS for the High-Luminosity
LHC. While ...initially conceived as a sensor for charged particles,
the intrinsic gain of LGADs makes it possible to detect low-energy
X-rays with good energy resolution and excellent time resolution
(tens of picoseconds). Using the Stanford Synchrotron Radiation
Lightsource (SSRL) at SLAC, several LGADs designs were characterized
with energies from 5 to 70 keV. The SSRL provides 10 ps pulsed
X-ray bunches separated by 2 ns intervals with an energy dispersion
(Δ
E
/
E
) of 10
-4
. LGADs from Hamamatsu Photonics (HPK)
and Brookhaven National Laboratory (BNL) with different thicknesses
ranging from 20 μm to 50 μm and different gain layer
designs were read out using fast amplification boards and digitized
with a high bandwidth and high sampling rate oscilloscope. PIN
devices from HPK and AC-LGADs from BNL were characterized as well. A
systematic and detailed characterization of the devices' energy
linearity, resolution, and time resolution as a function of X-ray
energy was performed for different biasing voltages at room
temperature and are reported in this work. The charge collection and
multiplication mechanism were simulated using Geant4 and TCAD
Sentaurus, providing an important handle for interpreting the data.
Abstract
This paper presents results that take a critical step toward
proving 10 ps timing resolution's feasibility for particle
identification in the TOPSiDE detector concept for the Electron-Ion
...Collider. Measurements of LGADs with a thickness of 35 μm
and 50 μm are evaluated with a 120 GeV proton beam. The
performance of the gain and timing response is assessed, including
the dependence on the reverse bias voltage and operating
temperature. The best timing resolution of UFSDs in a test beam to
date is achieved using three combined planes of 35 μm thick
LGADs at -30°C with a precision of 14.3 ± 1.5 ps.
Abstract
We present the first results from the HPSoC ASIC designed for readout of Ultra-fast Silicon Detectors. The 4-channel ASIC manufactured in 65 nm CMOS by TSMC has been optimized for 50 μm ...thick AC-LGAD. The evaluation of the analog front end with β-particles impinging on 3 × 3 AC-LGAD arrays (500 μm pitch, 200 × 200 μm
2
metal) confirms a fast output rise time of 600 ps and good timing performance with a jitter of 45 ps. Further calibration experiments and TCT laser studies indicate some gain limitations that are being investigated and are driving the design of the second-generation pre-amplification stages to reach a jitter of 15 ps.
Next generation Low Gain Avalanche Diodes (LGAD) produced by Hamamatsu photonics (HPK) and Fondazione Bruno Kessler (FBK) were tested before and after irradiation with ~1MeV neutrons at the JSI ...facility in Ljubljana. Sensors were irradiated to a maximum 1-MeV equivalent fluence of 2.5E15 N
eq
/cm
2
. The sensors analysed in this paper are an improvement after the lessons learned from previous FBK and HPK productions that were already reported in precedent papers. The gain layer of HPK sensors was fine-tuned to optimize the performance before and after irradiation. FBK sensors instead combined the benefit of Carbon infusion and deep gain layer to further the radiation hardness of the sensors and reduced the bulk thickness to enhance the timing resolution. The sensor performance was measured in charge collection studies using β-particles from a 90Sr source and in capacitance-voltage scans (C-V) to determine the bias to deplete the gain layer. The collected charge and the timing resolution were measured as a function of bias voltage at -30C. Finally a correlation is shown between the bias voltage to deplete the gain layer and the bias voltage needed to reach a certain amount of gain in the sensor. HPK sensors showed a better performance before irradiation while maintaining the radiation hardness of the previous production. FBK sensors showed exceptional radiation hardness allowing a collected charge up to 10 fC and a time resolution of 40 ps at the maximum fluence.
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