Wed·Mar 27, 2019Wednesday·March 27, 2019

1. 01*

   Half-life measurement of 65Ga with gamma-spectroscopy

   Gy. Gyürky🇭🇺 · Z. Halász · G.G. Kiss🇭🇺 · T. Szücs🇩🇪 · Zs. Fülöp🇭🇺

   The literature half-life value of 65Ga is based on only one experiment carried out more than 60 years ago and it has a relatively large uncertainty. In the present work this half-life is determined based on the counting of the gamma-rays following the beta-decay of 65Ga. Our new recommended half-life is 15.133 +- 0.028 min which is in agreement with the literature value but almost one order of magnitude more precise.

   nucl-exAppl.Radiat.Isot.(2019)·1 citation
2. 02*

   Further Theoretical Analysis on the $K^{-}{}^3\text{He}\to \Lambda pn$ Reaction for the $\bar{K}NN$ Bound-State Search in the J-PARC E15 Experiment

   Takayasu Sekihara (JAEA, Ibaraki)🇯🇵 · Eulogio Oset (Valencia U. & Valencia U., IFIC)🇪🇸 · Angels Ramos (Barcelona U., ECM & ICC, Barcelona U.)🇪🇸

   Based on the scenario that a $\bar{K}NN$ bound state is generated and it eventually decays into $\Lambda p$, we calculate the cross section of the $K^{-}{}^3\text{He}\to \Lambda pn$ reaction, which was recently measured in the J-PARC E15 experiment. We find that the behavior of the calculated differential cross section $d^2\sigma /d{M}_{\Lambda p}d{q}_{\Lambda p}$, where $M_{\Lambda p}$ and $q_{\Lambda p}$ are the $\Lambda p$ invariant mass and momentum transfer in the $(K^{-},n)$ reaction in the laboratory frame, respectively, is consistent with the experiment. Furthermore, we can reproduce almost quantitatively the experimental data of the $\Lambda p$ invariant mass spectrum in the momentum transfer window $350\text{ MeV}/c<q_{\Lambda p}<650\text{ MeV}/c$. These facts strongly suggest that the $\bar{K}NN$ bound state was indeed generated in the J-PARC E15 experiment.

   ↳ nucl-thhep-phnucl-exJPS Conf.Proc.(2019)·5 citations
3. 03*

   DPTC -- an FPGA-based trace compression

   G. Bruni · H. T. Johansson🇸🇪

   Recording of flash-ADC traces is challenging from both the transmission bandwidth and storage cost perspectives. This paper presents a configuration-free lossless compression algorithm which addresses both limitations, by compressing the data on-the-fly in the controlling field-programmable gate array (FPGA). Thus the difference predicted trace compression (DPTC) can easily be used directly in front-end electronics. The method first computes the differences between consecutive samples in the traces, thereby concentrating the most probable values around zero. The values are then stored as groups of four, with only the necessary least-significant bits in a variable-length code, packed in a stream of 32-bit words. To evaluate the efficiency, the storage cost of compressed traces is modeled as a baseline cost including the ADC noise, and a cost for pulses that depends on their amplitude and width. The free parameters and the validity of the model are determined by comparing it with the results of compressing a large set of artificial traces with varying characteristics. The compression method was also applied to actual data from different types of detectors, thereby demonstrating its general applicability. The compression efficiency is found to be comparable to popular general-purpose compression methods, while available for FPGA implementation using limited resources. A typical storage cost is around 4 to 5 bits per sample. Code for the FPGA implementation in VHDL and for the CPU decompression routine in C of DPTC are available as open source software, both operating at multi-100 Msamples/s speeds.

   ↳ physics.ins-detnucl-exIEEE Trans.Circuits Theor.(2019)·0 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.