FCC-ee interaction region backgrounds
International journal of modern physics. A, Particles and fields, gravitation, cosmology,
06/2020
Journal Article
SVX4 is the new silicon strip readout IC designed to meet the increased radiation tolerance requirements for Run IIb at the Tevatron collider. Devices have been fabricated, tested, and approved for ...production. The SVX4 design is a technology migration of the SVX3D design currently in use by CDF. Whereas SVX3D was fabricated in a 0.8-/spl mu/m radiation-hard process, SVX4 was fabricated in a standard 0.25-/spl mu/m mixed-signal CMOS technology using the "radiation tolerant by design" transistor topologies devised by the CERN RD49 collaboration. The specific cell layouts include digital cells developed by the ATLAS Pixel group, and full-custom analog blocks. Unlike its predecessors, the new design also includes the necessary features required for generic use by both the CDF and D0 experiments at Fermilab. Performance of the IC includes >20 MRad total dose tolerance, and /spl sim/2000 e-rms equivalent input noise charge with 40-pF input capacitance, when sampled at 132-ns period with an 80-ns preamp risetime. At the nominal digitize/readout rate of 106/53 MHz, the 9 mm/spl times/6.3 mm die dissipates /spl sim/2 mW/channel average at 2.5 V. A review of typical operation, details of the design conversion process, and performance measurements are covered.
The Compact Muon Solenoid (CMS) is one of the two large, general purpose experiments situated at the LHC at CERN. As with all high energy physics experiments, knowledge of the beam conditions and ...luminosity is of vital importance.
The Beam Conditions and Radiation Monitoring System (BRM) is installed in CMS to protect the detector and to provide feedback to LHC on beam conditions. It is composed of several sub-systems that measure the radiation level close to or inside all sub-detectors, monitor the beam halo conditions with different time resolution, support beam tuning and protect CMS in case of adverse beam conditions by firing a beam abort signal. This paper presents three of the BRM subsystems: the Fast Beam Conditions Monitor (BCM1F), which is designed for fast flux monitoring, measuring with nanosecond time resolution, both the beam halo and collision products; the Beam Scintillator Counters (BSC), that provide hit rates and time information of beam halo and collision products; and the Beam Conditions Monitors (BCM) used as a protection system that can trigger a beam dump when beam losses occur in order to prevent damage to the pixel and tracker detectors. A description of the systems and a characterization on the basis of data collected during LHC operation is presented.
To obtain full charge collection the CMS silicon detectors should be able to operate at high bias voltage. We observed that multiguard structures enhance the breakdown performance of the devices on ...several tens of baby detectors designed for CMS. The beneficial effects of the multiguard structures still remains after the strong neutron irradiation performed to simulate the operation at the LHC.
Oxygenated and standard (not oxygenated) silicon diodes processed by two different manufacturers (ST Microelectronics and Micron Semiconductor) have been irradiated by low (27 MeV) and high- (24 GeV) ...energy protons. The leakage current density increase rate (/spl alpha/) and its annealing do not show any significant dependence on oxygenation and are the same for both manufacturers. Oxygenation improves the radiation hardness by decreasing the acceptor introduction rate (/spl beta/) and mitigating the depletion voltage (V/sub dep/) increase. Nevertheless, standard ST diodes present /spl beta/ values lower than Micron standard devices and close to oxygenated devices, whose /spl beta/s are similar for both manufacturers. The amplitude of the V/sub dep/ reverse annealing is reduced by oxygenation, which in addition delays the electrically active defect increase, at least for high-energy protons. Oxygenation is consequently the best approach for silicon substrate radiation hardening.
The new silicon detector design for CDF relies on advanced packaging solutions in order to attain the strict small size and low mass requirements dictated by the experiment's physics program. The ...silicon strip detector at CDF is composed of overlaying silicon sensors in the form of a barrel around the colliding beam. The electronic instrumentation (sensors, readout, and transceiver chips) is assembled into the staves of this barrel. In this paper we describe the development of the mini port card (MPC). The MPC is located at one of the ends of the stave, and it is responsible for signal translation and repetition from the readout chips to and from the data acquisition system (DAQ). The MPC's development has taken two approaches that use different technologies. One of the approaches uses BeO as the board substrate (BeO-MPC), while the other approach uses a hybrid rigid-flexible polyimide substrate (Poly-MPC). We present test results of pre-production parts, each one assembled with a different MPC packaging technology. Complete thermal and electrical characterization of the MPC is shown, and the advantages and disadvantages of both technologies, as well as their influence in the overall system performance, are presented.
The purpose of this work is to study layout solutions aimed at increasing the breakdown voltage in silicon micro-strip detectors. Several structures with multiple floating guards in different ...configurations have been designed and produced on high-resistivity silicon wafers. The main electrical characteristics of these devices have been measured before and after irradiation. Both radiation-induced surface and bulk damage effects were considered as well. The highest breakdown voltage was found on devices featuring p/sup +/ guards without field plates. A simulation study has been carried out on simplified structures to evaluate the distribution of the breakdown field as a function of the guard layout. The aim was design optimization.
Two silicon microstrip detectors, one fabricated from a standard and the second from a highly oxygenated substrate, were non-uniformly irradiated by
24
GeV
protons to fluences ranging between 2.3 and
...6.3×10
14
cm
−2
. Charge collection efficiency measurements, performed by pulsing the detectors with a
1060
μm
wavelength laser, show that the beneficial effect of the oxygenation remains, although reduced with respect to that observed by
C–
V measurements on diodes fabricated with the detectors.
P-channel MOSFETs of a commercial 0.25 /spl mu/m CMOS technology have been irradiated by high linear energy transfer (LET) iodine (I) and low LET silicon (Si) ions up to 300 Mrad(Si) and 500 ...Mrad(Si), respectively. Threshold voltage variations (/spl Delta/V/sub TH/) up to -0.46 V and -0.44 V have been measured at the highest I and Si doses. Both oxide positive trapped charge (/spl Delta/V/sub OX/) and interface states (/spl Delta/V/sub IT/) contribute to /spl Delta/V/sub TH/ with a ratio /spl Delta/V/sub IT///spl Delta/V/sub OX/ /spl ap/ 1 (< 1) for high (low) LET ions. After 40 days at room temperature, most of the positive charge is recombined by electron tunneling from the oxide interfaces, while only a small amount (6%-16%) of interface states is annealed. A huge 1/f noise increase (higher for I ions) is observed after irradiation. Finally, radiation induced soft breakdown (radiation-induced leakage current) conduction through the gate oxide is generated by high (low) LET ions for |V/sub g/| > 1.6 V (> 3.4 V).
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