J. Kierstead

Radiation hardness of high resistivity magnetic Czochralski silicon detectors after gamma, neutron, and proton radiations

High resistivity magnetic Czochralski Si detectors were irradiated with /sup 60/Co gamma rays, neutrons, and protons to various doses/fluences, along with control float zone Si detectors. 1) It has been found that for gamma radiation, magnetic Czochralski Si detectors behave similarly to the high-temperature, long-time (HTLT) oxygenated float zone Si detectors. There is no space charge sign inversion and there is a buildup of positive space charges. The rate for this buildup is much higher than that for the oxygenated Si detectors and is proportional to the oxygen concentration. 2) For neutron radiation, there is little difference between magnetic Czochralski and control float zone silicon detectors. Space charge sign inversion is observed for both materials. The introduction rate of deep acceptors (beta) for magnetic Czochralski Si detectors is slightly less than that for control float zone Si detectors, and 3) for proton radiation (10 and 20 MeV), although the space charge sign inversion is also observed for magnetic Czochralski Si detectors, the 1-MeV neutron-equivalent space charge sign inversion fluence is about three times higher than that of magnetic Czochralski Si detectors irradiated with neutrons. Also, the acceptor introduction rate beta is about half of that for oxygenated Si detectors. Thus, high resistivity magnetic Czochralski Si behaves in a similar manner to the HTLT oxygenated float zone Si detectors and is even more radiation resistant to damage caused by charged particles.

Performance of the SiGe HBT 8HP and 8WL technologies after high dose/fluence radiation exposure

An assessment of the radiation tolerance of the latest generation IBM silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) technologies (SiGe 8WL and SiGe 8HP) at extreme dose/fluence is reported. These BiCMOS technologies are of great interest for analog readout circuits in high energy physics detectors, especially the planned upgrade of the ATLAS detector for the upgraded Large Hadron Collider (sLHC) in Geneva, Switzerland. These third-generation, 130 nm SiGe HBTs show promise to operate at lower power than CMOS circuits provided that they can be shown to be sufficiently radiation tolerant. This study presents evidence of the radiation tolerance of these two candidate technologies with parametric measurements after irradiation up to a fluence of 1016 1 MeV equivalent neutrons/cm2 and a gamma dose of 100 Mrad (SiO2).

Radiation hardness evaluation of a 130 nm SiGe BiCMOS technology for the ATLAS electronics upgrade

Final results for a comprehensive radiation hardness evaluation of a high performance, low cost, 130nm SiGe BiCMOS technology are presented. After a survey of several available SiGe technologies, one was chosen in terms of performance, power consumption, radiation hardness, and cost and it is presented as a suitable technology for the front-end electronics of the Inner Detector and the Liquid Argon calorimeter. Gamma, neutron and proton irradiations have been performed up to target dose and fluence values, together with ELDRS assessment.

Evaluation of Two SiGe HBT Technologies for the ATLAS sLHC Upgrade

As previously reported, silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) technologies promise several advantages over CMOS for the front-end readout electronics for the ATLAS upgrade. Since our last paper, we have evaluated the relative merits of the latest generations of IBM SiGe HBT BiCMOS technologies, the 8WL and 8HP platforms. These 130nm SiGe technologies show promise to operate at lower power than CMOS technologies and would provide a viable alternative for the Silicon Strip Detector and Liquid Argon Calorimeter upgrades, provided that the radiation tolerance studies at multiple gamma and neutron irradiation levels, included in this investigation, show them to be sufficiently radiation tolerant.

Si-JFET devices and related noise behavior under irradiation

Monolithic N-channel junction field effect transistors (NJFETs) dc characteristics, small signal parameters and noise have been studied from 300 K down to cryogenic temperatures before and after irradiation with 60 Co γ-rays and fast neutrons (1 MeV). Radiation induced effects on dc parameters and noise are reviewed. Noise spectral density measurements performed at various temperatures have shown that the radiation induces a noise increase which is temperature and frequency dependent.

ELECTROMAGNETIC COMPATIBILITY OF A DC POWER DISTRIBUTION SYSTEM FOR THE ATLAS LIQUID ARGON CALORIMETER

The front-end electronics of the ATLAS Liquid Argon Calorimeter is powered by DC/DC converters nearby the front-end crates. They are fed by AC/DC converters located in a remote control room through long power cables. The stability of the power distribution scheme is compromised by the impedance of the long interconnection cable, and proper matching of the converters dynamic impedances is required. Also, the long power cable fed by a powerful AC/DC converter is a source of electromagnetic interferences in the experimental area. The optimal grounding and shielding con guration to minimize these EMI is discussed.

The ATLAS calorimeter preamplifier : performance, radiation damage, electrostatic discharge resistance, reliability and manufacturing issues

The requirements, design, measured specification of the ATLAS liquid argon (LAr) calorimeter preamplifiers are reviewed. The experience gained so far in production, the quality assurance and testing, as well as the reliability estimate according to MILSTRESS standard will be discussed.

Power distribution in Harsh environment: Measurement on commercial power brick

Experimental results about tests on a commercial power bricks under radiations is presented. The experimental obtained results are very interesting in order to evaluate the possibility to use particular electronic device, which can be used in harsh environment. The power bricks tested in this paper highlights interesting technical specification.

Observation of gamma irradiation-induced suppression of reverse annealing in neutron irradiated MCZ Si detectors

For the development of radiation-hard Si detectors for the SiD BeamCal program for the future ILC (International Linear Collider), n-type MCZ Si detectors have been irradiated first by fast neutrons to flueneces of 1.5×1014 and 3×1014 neq/cm2, and then by gamma up to 500 Mrad. The motivation of this mixed radiation project is to develop a Si detector that can utilize the gamma/electron radiation that exists in the ICL radiation environment, which also includes neutrons. By using the positive space charge (SC) created by gamma radiation in MCZ Si detectors, one can cancel the negative space charge created by neutrons, thus reducing the overall/net space charge density and therefore the full depletion voltage of the detector.