arXiv subjects

E. Won

Publications and source records attributed to E. Won.

43 records · Page 3Linked to original sources

arXiv2007

Fabrication of Analog Electronics for Serial Readout of Silicon Strip Sensors

A set of analog electronics boards for serial readout of silicon strip sensors was fabricated. A commercially available amplifier is mounted on a homemade hybrid board in order to receive analog signals from silicon strip sensors. Also, another homemade circuit board is fabricated in order to translate amplifier control signals into a suitable format and to provide bias voltage to the amplifier as well as to the silicon sensors. We discuss technical details of the fabrication process and performance of the circuit boards we developed.

physics.ins-det↗

arXiv2007

A Hardware Implementation of Artificial Neural Network Using Field Programmable Gate Arrays

An artificial neural network algorithm is implemented using a field programmable gate array hardware. One hidden layer is used in the feed-forward neural network structure in order to discriminate one class of patterns from the other class in real time. With five 8-bit input patterns, six hidden nodes, and one 8-bit output, the implemented hardware neural network makes decision on a set of input patterns in 11 clocks and the result is identical to what to expect from off-line computation. This implementation may be used in level 1 hardware triggers in high energy physics experiments

physics.ins-det↗

arXiv2007

Semileptonic b to u transition

Experimental studies of charmless semileptonic B decays can be broadly categorized into inclusive and exclusive measurements depending on how the final states are treated. The inclusive method measures the decay rate $Γ(B \to X_u \ell ν)$, where $X_u$ is known as the hadronic system that does not contain charm-quark. On the other hand, the exclusive method measures the decay rates for exclusive final states such as $B \to π\ell ν$ and $ρ\ell ν$. Two methods give not only different efficiencies and signal-to-background ratios, but also different theoretical calculations to be used in order to extract $|V_{ub}|$. Using both approaches and comparing the results will help us verify the robustness of the theoretical error estimation, which dominates the current uncertainty in the determination of $|V_{ub}|$. Progress in last few years will be summarized in this presentation.

hep-ex↗

arXiv2006

Precise Numerical Solutions of Potential Problems Using Crank-Nicholson Method

A new numerical treatment in the Crank-Nicholson method with the imaginary time evolution operator is presented in order to solve the Schrödinger equation. The original time evolution technique is extended to a new operator that provides a systematic way to calculate not only eigenvalues of ground state but also of excited states. This new method systematically produces eigenvalues with accuracies of eleven digits with the Cornell potential that covers non-perturbative regime. An absolute error estimation technique based on a power counting rule is implemented. This method is examined with exactly solvable problems and produces the numerical accuracy down to 10$^{-11}$.

physics.comp-ph↗

arXiv2002

Neutron beam test of CsI crystal for dark matter search

We have studied the response of Tl-doped and Na-doped CsI crystals to nuclear recoils and $γ$'s below 10 keV. The response of CsI crystals to nuclear recoil was studied with mono-energetic neutrons produced by the $^3$H(p,n)$^3$He reaction. This was compared to the response to Compton electrons scattered by 662 keV $γ$-ray. Pulse shape discrimination between the response to these $γ$'s and nuclear recoils was studied, and quality factors were estimated. The quenching factors for nuclear recoils were derived for both CsI(Na) and CsI(Tl) crystals.

nucl-ex↗

arXiv1999

A fast programmable trigger for isolated cluster counting in the BELLE experiment

We have developed a fast programmable trigger processor board based on a field programmable gate array and a complex programmable logic device for use in the BELLE experiment. The trigger board accommodates 144 ECL input signals, 2 NIM input signals, 24 ECL output signals, and the VME bus specification. An asynchronous trigger logic for counting isolated clusters is used. We have obtained trigger latency of 50 ns with a full access to input and output signals via a VME interface. The trigger logic can be modified at any time depending on the experimental conditions.

physics.ins-det↗

arXiv1999

Test of CsI(Tl) crystals for the Dark Matter Search

Searches for weakly interacting massive particles(WIMP) can be based on the dete ction of nuclear recoil energy in CsI(Tl) crystals. We demonstrate that low energy gamma rays down to few keV is detected with CsI(Tl) crystal detector. A clear peak at 6 keV is observed using X-ray source. Good energy resolution and linearity have been achieved down to X-ray region. In addition, we also show that alpha particles and gamma rays can be clearly separated using the different time characteristics of the crystal.

physics.ins-det↗