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Stone, S.

Publications and source records attributed to Stone, S..

15 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

First Beam Test of UT Sensors with the SALT 3.0 Readout ASIC

This note presents the results of a beam test conducted at the Fermilab test beam facility in March 2019. The beam test represents the first such test of the UT readout ASIC, SALT 3.0, in a beam with production UT sensors. Two sensors were tested, one an unirradiated p-in-n sensor, and the second a n-in-p sensor irradiated to twice the maximum expected uence. The beam test demonstrates that the SALT 3.0 ASIC meets our specifications, and can be used for the production. Due to specific issues with the data acquisition system that will not be present in the system in LHCb, a higher threshold was used in the beam test, corresponding to about $6 \sigma$ on the noise. With this higher threshold, the signal-to-noise ratio (S/N) and efficiency are measured. For the unirradiated sensor, a S/N of about 12 is achieved, with a single-hit effciency of at least 99.5%. For the irradiated sensor, a S/N of about 11 is obtained, with a single-hit effciency of about 94%. In the final system in LHCb with a proper threshold of about $3-4 \sigma$ of the noise, we expect to achieve a single-hit effciency of at least 99.5%.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

Response Variability in Commercial MOSFET SEE Qualification

Single-event effects (SEE) evaluation of five different part types of next generation, commercial trench MOSFETs indicates large part-to-part variation in determining a safe operating area (SOA) for drain-source voltage (V DS ) following a test campaign that exposed >50 samples per part type to heavy ions. These results suggest a determination of a SOA using small sample sizes may fail to capture the full extent of the part-to-part variability. An example method is discussed for establishing a Safe Operating Area using a one-sided statistical tolerance limit based on the number of test samples. Finally, burn-in is shown to be a critical factor in reducing part-to-part variation in part response. Implications for radiation qualification requirements are also explored.

43 PARTICLE ACCELERATORS↗
DOE OSTI2011

Amplitude analyses of the decays χ c1 →ηπ⁺π⁻ and χ c1 →η'π⁺π⁻

Using a data sample of 2.59×10⁷ ψ(2S) decays obtained with the CLEO-c detector, we perform amplitude analyses of the complementary decay chains ψ(2S)→γχ c1 ; χ c1 →ηπ⁺π⁻ and ψ(2S)→γχ c1 ; χ c1 →η'π⁺π⁻. We find evidence for an exotic P-wave η'π amplitude, which, if interpreted as a resonance, would have parameters consistent with the π₁(1600) state reported in other production mechanisms. We also make the first observation of the decay a₀(980)→η'π and measure the ratio of branching fractions B(a₀(980)→η'π)/B(a₀(980)→ηπ)=0.064±0.014±0.014. The ππ spectrum produced with a recoiling η is compared to that with η' recoil.

Adams, G. S.↗
DOE OSTI2011

Studies of D⁺→{η',η,Φ}e⁺ν e

We report the first observation of the decay D⁺→η'e⁺ν e in two analyses, which combined provide a branching fraction of B(D⁺→η'e⁺ν e )=(2.16±0.53±0.07)×10⁻⁴. We also provide an improved measurement of B(D⁺→ηe⁺ν e )=(11.4±0.9±0.4)×10⁻⁴, provide the first form factor measurement, and set the improved upper limit B(D⁺→Φe⁺ν e )<0.9×10⁻⁴ (90%C.L.).

Yelton, J.↗