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ABSTRACT: Simple dosimeters are described for single-event effects from cosmic-rays and nuclear-spallation reactions as well total-dose effects and displacement damage. Measurement of these complex radiation environments is complicated by fluctuating temperature and voltages limit measurements below one rad.
Radiation and Its Effects on Components and Systems (RADECS), 2009 European Conference on; 10/2009
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H. Chabane,
J. R. Vaill,
B. Barelaud,
F. Wrobel,
Y. Calzavara, P. J. McNulty,
J. L. Decossas,
P. Garcia,
L. Dusseau,
J. Boch,
F. Saign
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ABSTRACT: The aim of this work is to validate experimentally the results of the Monte Carlo Recoil Energy Determination (MC-RED) nuclear physics code used to determine the deposited energy in a silicon volume taking into account the probabilistic approach of the physical phenomenon. A silicon sensor has been used to measure the deposited energy spectrum after an irradiation with a 14 MeV neutron source. Neutrons of 14 MeV were produced by the SAMES accelerator of the Valduc CEA research center. The experimental results were compared with the one obtained by the MC-RED code in the same silicon volume. To compare experiment and simulations, it requires that the complete neutron field be specified. We have to take into account the facility cell environment. Nuclear simulations were performed with the MCNP code to determine with accuracy the energy spectra of neutrons and gamma rays produced by this facility on the sensor. It is shown that the contribution of secondary neutrons is not negligible
IEEE Transactions on Nuclear Science 01/2007; · 1.45 Impact Factor
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ABSTRACT: Floating Gate (FG) nonvolatile memories are based on a tiny polysilicon layer (the FG) which can be permanently charged with electrons or holes, thus changing the threshold voltage of a MOSFET. Every time a FG is hit by a high energy ion, it experiences a charge loss, depending on the ion linear energy transfer (LET) and on the transistor geometrical and electrical characteristics. This paper discusses the opportunities to use this devices as single an ion dosemeter with sub-micrometer spatial resolution and capable of distinguish the impinging ion LET.
Radiation Protection Dosimetry 02/2006; 122(1-4):457-9. · 0.82 Impact Factor
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P J McNulty,
Kelvin F Poole,
M Crissler,
J Reneau,
G Cellere,
A Paccagnella,
A Visconti,
M Bonanomi,
Dave Stroebel,
Michael Fennell,
Roger Perez
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ABSTRACT: UVPROM memory devices employing FGMOS transistors as memory cells make excellent dosemeters for applications involving ionising radiation. With proper preparation and programming, these devices can be used in remote-sensing applications in high-radiation environments with no power required during exposure.
Radiation Protection Dosimetry 02/2006; 122(1-4):460-2. · 0.82 Impact Factor
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J.-R. Vaille,
F. Ravotti,
P. Garcia,
M. Glaser,
S. Matias,
K. Idri,
J. Boch,
E. Lorfevre, P.J. McNulty,
F. Saigne,
L. Dusseau
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ABSTRACT: A version of the Optically Stimulated Luminescence (OSL) sensor specifically developed to monitor the dose online in radiation facilities is presented and calibrated with <sup>60</sup>Co. The lowest dose measurable at the extremity of a 20 m cable is 0.3 mGy.
IEEE Transactions on Nuclear Science 01/2006; · 1.45 Impact Factor
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P.J. McNulty,
K.F. Poole,
M. Crisler,
J. Reneau,
G. Cellere,
A. Paccagnella,
D. Stroebel,
M. Fennell,
R. Perez,
M. Randall,
L. Call
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ABSTRACT: The dynamic range and resolution of dosimeters based on floating-gate transistors with electronic readout can be significantly improved by simple changes in the readout process and an increase in the number of memory cells used. The new procedure is illustrated using 8-Mbit UVPROMs from ST Microelectronics.
IEEE Transactions on Nuclear Science 01/2006; · 1.45 Impact Factor
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ABSTRACT: A commercial ultraviolet erasable programmable read-only memory (UVPROM) was used to demonstrate a dosimetry technique for both ground and space applications. An equivalent amount of UV to reproduce the same amount of erasure was used to calibrate dose. The new method of readout, unlike other methods, does not require the evidence of exposure to be destroyed in the course of a measurement. It requires power only during readout. Results from an experiment using this technique aboard the Microelectronics and Photonics Test Bed (MPTB) satellite are discussed. Application of Extreme Value Theory is used to analyze whether early failures in the device were statistically feasible or more likely due to large, rare energy depositions. A new dosimeter approach using a change injection method that will eliminate the need for UV as a metric is also presented as well new experiments for the devices under test aboard MPTB.
IEEE Transactions on Nuclear Science 01/2006; · 1.45 Impact Factor
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Radiation and Its Effects on Components and Systems, 2005. RADECS 2005. 8th European Conference on; 10/2005
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ABSTRACT: The energy-deposition spectra measured by the CRRES (Combined Release and Radiation Effects Satellite) pulse height analyzer (PHA) experiment are reexamined to determine the relative contributions from the different mechanisms by which large localized energy-deposition events can be generated in silicon detector volumes flown in space. Comparisons with calculations generated by the CUPID simulation model modified to include pion-production and elastic-scattering events are used to generate a "best fit" trapped proton spectrum that is compared to the predictions of the NASA models for the CRRES orbit.
IEEE Transactions on Nuclear Science 01/2005; · 1.45 Impact Factor
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ABSTRACT: We compare deposition spectra from monoenergetic neutron irradiation to CUPID simulations of the same neutron exposures. CUPID does not agree with the experimental data unless pion production is included in the neutron-nucleon interaction. Pion-production events result in slightly more single-event effects (SEEs) for devices with relatively large sensitive volumes and low thresholds for upset but dramatically fewer events for the same sensitive volume when the threshold is high.
IEEE Transactions on Nuclear Science 01/2004; · 1.45 Impact Factor
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ABSTRACT: Radiation effects on floating-gate-metal-oxide-semiconductor (FGMOS) devices in the passive or quiescent mode are due to a combination of the removal of negative charge from the floating gate and the generation and trapping of positive charge in the gate oxide. The latter is subject to room temperature annealing but not the former. No difference was observed between the effects of trapped charge on transistors in "0" and "1" logic states. The amount of negative charge per unit dose that is removed from the floating gates by heavy ions is less than that removed by 6 MeV electrons, which at least partially explains the sublinear dependence on linear energy transfer.
IEEE Transactions on Nuclear Science 01/2003; · 1.45 Impact Factor
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R.A. Reed,
P.W. Marshall,
H.S. Kim, P.J. McNulty,
B. Fodness,
T.A. Jordan,
R. Reedy,
C. Tabbert,
M.S.T. Liu,
W. Heikkila,
S. Buchner,
R. Ladbury,
K.A. LaBel
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ABSTRACT: Historically, proton-induced single-event effects (SEES) ground test data are collected independent of the orientation of the microelectronic device to the proton beam direction. In this study, we present experimental and simulation evidence that shows an effect of over an order of magnitude on the proton-induced single-event upset (SEU) cross section when the angle of incidence of the proton beam is varied. The magnitude of this effect is shown to depend on the incidence proton energy and the device critical charge. The angular effect is demonstrated for Silicon-On-Sapphire and Silicon-On-Insulator technologies, but would not necessarily be limited to these technologies.
IEEE Transactions on Nuclear Science 01/2003; · 1.45 Impact Factor
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ABSTRACT: Modern photometer systems need to be accompanied by dosimeters
that monitor exposure to total ionizing dose, ultraviolet light, and the
flux of particles with linear energy transfer above some threshold
value. These detectors should minimize space, weight, power, cost, and
telemetry. A new approach is described in which single-chip, two-chip,
or three-chips systems incorporated into the photometer's interface
circuits measure the above while including information on the status of
charge trapping in oxides and thermal noise at p-n junctions
IEEE Transactions on Nuclear Science 01/2002; · 1.45 Impact Factor
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ABSTRACT: We present results from a radiation dosimeter based on the erasure
of floating-gate MOS transistors. Background theory and analysis
necessary to describe the operation of the sensor are presented
IEEE Transactions on Nuclear Science 01/2002; · 1.45 Impact Factor
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ABSTRACT: Different effects are observed for FGMOS cells exposed while in "0" and "1" states. If reprogrammed to the "0" state, cells exposed in the 1 state take longer to erase under UV exposure than those cells exposed in the "0" state. This difference in UV-erasure time is attributed to charge removal from the floating gate in the "0" state cells. This difference in erasure time between the "0" and "1" states is proportional to the absorbed dose and is not dependent on annealing and temperature, a big advantage in most dosimetry applications. Cells exposed in the "1" state are also observed to fail to program at very low doses if programming is attempted within a few days of exposure.
Radiation and Its Effects on Components and Systems, 2001. 6th European Conference on; 10/2001
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ABSTRACT: Extreme value analysis applied to ground test data provides a new
method for predicting the first cell to fail in an array of EPROM memory
cells exposed to ionizing radiation. Which cell fails first is a
function of the dose absorbed by each as well as the cell-to-cell
variations in manufacturing with processing variations apparently
dominating fluctuations in absorbed dose. The method is applied to the
ground controls of UVPROMs flown on MPTB. These procedures can be used
to screen devices for flight parts. Power-law dependence between the
rate of electrons leaving the floating gate and the absorbed dose is
observed, and it may explain the SEU immunity observed in EPROM memory
cells flown in space
IEEE Transactions on Nuclear Science 01/2001; · 1.45 Impact Factor
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ABSTRACT: A method is described for measuring the sensitive volume of the
oxide which makes up the collection region for erasure surrounding the
floating gate of the FAMOS cell of a UVPROM using the data acquired from
the output of the pins of the device. A direct measurement of the dose
required to erase the Floating gate Avalanche injected metal oxide
silicon (FAMOS) cell yields a measurement of the volume of oxide which
collects the charge. Another method using target theory to determine the
sensitive volume of the device is also presented with good agreement
between the methods. The sensitive volume depends on the LET of the
radiation. The ramifications for microdosimetry and cell failure are
discussed as well as for the long term use aspects of nonvolatile
memories
IEEE Transactions on Nuclear Science 01/2001; · 1.45 Impact Factor
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G. Polge,
L. Dusseau,
S. Matias,
D. Gensanne,
D. Plattard,
J. Fesquet,
J. Gasiot, P.J. McNulty,
M. Davis,
M. Tortora,
N. Iborra-Brassart,
D. Porcheron,
J.B. Dubois,
N. Ailleres,
R. Delard
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ABSTRACT: A synthesis of different radiotherapy applications of a previously
described dose mapping system is presented. The principle of the
optically stimulated luminescent films and reader is reviewed. The
different dose maps obtained are presented and the results discussed
Nuclear Science Symposium Conference Record, 2000 IEEE; 02/2000
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ABSTRACT: Simulations to determine the threshold LET as a function of the length of the ion track are consistent with there being two regions of charge collection. In the top layer which contains the depletion region all the charge generated is collected in time to upset the device. In the next layer, 10% to 20% of the charge generated is collected and contributes to upsetting the device. This second layer of partial charge collection may significantly impact the accuracy of SEU predictions involving low-energy neutrons and protons. A simple method of including this contribution in calculations is proposed.
IEEE Transactions on Nuclear Science 01/2000; · 1.45 Impact Factor
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ABSTRACT: A new method is described for measuring the doses absorbed by microstructures from an exposure to ionizing radiation. The decrease in the duration of ultraviolet light (UV) exposure required to erase each cell of a commercial UltraViolet erasable Programmable Read Only Memory (UVPROM) correlates with the dose absorbed by the floating gate of that transistor. This technique facilitates analysis of the microdose distribution across the array and the occurrence of Single Event Upsets (SEU) like anomalous shifts due to rare large energy-deposition events.
IEEE Transactions on Nuclear Science 01/2000; · 1.45 Impact Factor
