Demonstration and Comparison of Operation of Photomultiplier Tubes at Liquid Argon Temperature

Liquified noble gases are widely used as a target in direct Dark Matter searches. Signals from scintillation in the liquid, following energy deposition from the recoil nuclei scattered by Dark Matter particles (e.g. WIMPs), should be recorded down to very low energies by photosensors suitably designed to operate at cryogenic temperatures. Liquid Argon based detectors for Dark Matter searches currently implement photo multiplier tubes for signal read-out. In the last few years PMTs with photocathodes operating down to liquid Argon temperatures (87 K) have been specially developed with increasing Quantum Efficiency characteristics. The most recent of these, Hamamatsu Photonics Mod. R11065 with peak QE up to about 35%, has been extensively tested within the R&D program of the WArP Collaboration. During these testes the Hamamatsu PMTs showed superb performance and allowed obtaining a light yield around 7 phel/keVee in a Liquid Argon detector with a photocathodic coverage in the 12% range, sufficient for detection of events down to few keVee of energy deposition. This shows that this new type of PMT is suited for experimental applications, in particular for new direct Dark Matter searches with LAr-based experiments

The Liquid Argon In A Testbeam (LArIAT) Experiment

The LArIAT liquid argon time projection chamber, placed in a tertiary beam of charged particles at the Fermilab Test Beam Facility, has collected large samples of pions, muons, electrons, protons, and kaons in the momentum range 300-1400 MeV/c. This paper describes the main aspects of the detector and beamline, and also reports on calibrations performed for the detector and beamline components

Measurement of the (π−\pi^-, Ar) total hadronic cross section at the LArIAT experiment

We present the first measurement of the negative pion total hadronic cross section on argon, which we performed at the Liquid Argon In A Testbeam (LArIAT) experiment. All hadronic reaction channels, as well as hadronic elastic interactions with scattering angle greater than 5~degrees are included. The pions have a kinetic energies in the range 100-700~MeV and are produced by a beam of charged particles impinging on a solid target at the Fermilab Test Beam Facility. LArIAT employs a 0.24~ton active mass Liquid Argon Time Projection Chamber (LArTPC) to measure the pion hadronic interactions. For this measurement, LArIAT has developed the ``thin slice method", a new technique to measure cross sections with LArTPCs. While generally higher than the prediction, our measurement of the ($\pi^-$,Ar) total hadronic cross section is in agreement with the prediction of the Geant4 model when considering a model uncertainty of $\sim$5.1\%.Comment: 15 pages, 15 figures, 3 tables, accepted by PR

Calorimetry for low-energy electrons using charge and light in liquid argon

Precise calorimetric reconstruction of 5-50 MeV electrons in liquid argon time projection chambers (LArTPCs) will enable the study of astrophysical neutrinos in DUNE and could enhance the physics reach of oscillation analyses. Liquid argon scintillation light has the potential to improve energy reconstruction for low-energy electrons over charge-based measurements alone. Here we demonstrate light-augmented calorimetry for low-energy electrons in a single-phase LArTPC using a sample of Michel electrons from decays of stopping cosmic muons in the LArIAT experiment at Fermilab. Michel electron energy spectra are reconstructed using both a traditional charge-based approach as well as a more holistic approach that incorporates both charge and light. A maximum-likelihood fitter, using LArIAT's well-tuned simulation, is developed for combining these quantities to achieve optimal energy resolution. A sample of isolated electrons is simulated to better determine the energy resolution expected for astrophysical electron-neutrino charged-current interaction final states. In LArIAT, which has very low wire noise and an average light yield of 18 pe/MeV, an energy resolution of $\sigma/E \simeq 9.3\%/\sqrt{E} \oplus 1.3\%$ is achieved. Samples are then generated with varying wire noise levels and light yields to gauge the impact of light-augmented calorimetry in larger LArTPCs. At a charge-readout signal-to-noise of S/N $\simeq$ 30, for example, the energy resolution for electrons below 40 MeV is improved by $\approx$ 10%, $\approx$ 20%, and $\approx$ 40% over charge-only calorimetry for average light yields of 10 pe/MeV, 20 pe/MeV, and 100 pe/MeV, respectively

Plant viruses in a current (2017) system of ICTV taxonomy with the proposals of polish names for species. Part 1. Viruses with DNA genome

Krótko przypomniano źródła informacji o zasadach taksonomii wirusów i uzasadniono włączenie do tekstu wirusów grzybów oraz wiroidów. Wykaz wirusów w tej części obejmuje rodziny Geminiviridae, Nanoviridae, Caulimoviridae i Rhizidioviridae.The sources of information concerning the principles of virus taxonomy were briefly recalled including International Committee on Taxonomy of Viruses (ICTV) Reports as well as special papers published in foreign and Polish scientific journals. The viruses infecting fungi were included to the list because they may become a tool for controlling fungus diseases of plants. The viroids were included as well, because they are present in all the newest ICTV Reports. The type species for particular virus taxons are marked with an asterisk. We decided to add the acronyms for official English names of virus species. They are not obligatory but they are commonly used. Polish names for virus species are needed in scientific papers published in Polish, as well as for handbooks and teaching process of plant pathology and virology and also in various law acts and documents produced by state and local administration. The list of plant viruses officially accepted by ICTV with Polish names for species was recently published in 2002 and 2007 so it has to be actualized. Based on the list of plants and fungi viruses and viroids included in ICTV Master Species List 2016 v 1.3 (https://talk.ictvonline.org/files/master-species-lists/m/msl/6776) as well as in the “Virus taxonomy. Ninth Report of ICTV” [King et al. 2012, Elsevier Academic] and according to the order of the mentioned viruses in these publications, we presented the propositions of Polish names of viruses with the DNA genomes [ssDNA and dsDNA (RT)]. The list of virus species includes families Geminiviridae, Nanoviridae, Caulimoviridae and Rhizidioviridae. Very short, almost concise description of the mentioned families is presented. Other virus species will be listed in a series of publications (parts 2–4)

Plant viruses in a current (2017) system of ICTV taxonomy with the proposals of Polish names for species. Part II. Viruses with genome in a form of dsRNA, ssRNA of anti- (-) or ambisense (+/-) orientation and some unusual viruses with (+)ssRNA genome and viroids

Krótko przypomniano zasady nazewnictwa taksonów wirusów oraz skomentowano zmiany w klasyfikacji i nazwach taksonów, jakie zaszły po publikacji 8. Raportu ICTV. Lista wirusów obejmuje gatunki z rodzin: Reoviridae, Totiviridae, Chrysoviridae, Hypoviridae, Partitiviridae, Endornaviridae, Narnaviridae, Rhabdoviridae, Ophioviridae, Fimoviridae, Phenuiviridae, Tospoviridae, Pseudoviridae i Metaviridae, oraz wiroidy zaliczane do rodzin Avsunviroidae i Pospiviroidae.The principles of virus taxonomy established by International Committee on Taxonomy of Viruses (ICTV) are briefly recalled and some changes that were introduced to the classification system after 8th Report of ICTV are discussed. These changes should not by introduced so often because they cause some doubts concerning the whole system. Some of these changes do not seem fortunate. The examples: Alpha- and Betacryptovirus to Alpha- and Betapartitivirus. The family Bunyaviridae disappeared. The genus name Tospovirus was replaced by Orthotospovirus. Introduction of generic name to the name of the virus species (Tomato spotted wilt orthotospovirus instead of Tomato spotted wilt virus, and many other similar changes) does not seem to be justified. Species names of such type were proposed in early seventies of 20th century and they were not accepted by plant virologists. Based on the list of plants and fungi viruses and viroids included in ICTV Master Species List 2016 v 1.3 (https://talk.ictvonline.org/files/masterspecies-lists/m/msl/6776), in this part of our publication we presented the proposals of Polish names of viruses with the RNA genomes [dsRNA, (-)ssRNA, (+/-)ssRNA, some unusual (+)ssRNA] as well as the proposals of Polish names for viroids – small, circular, non-protein coding ssRNAs plant pathogens. The virus species listed in this part belong to the families: Reoviridae, Totiviridae, Chrysoviridae, Hypoviridae, Partitiviridae, Endornaviridae, Narnaviridae, Rhabdoviridae, Ophioviridae, Fimoviridae, Phenuiviridae, Tospoviridae, Pseudoviridae, Metaviridae. The viroids grouped in the families Avsunviroidae, Pospiviroidae were included. Although they are not viruses, but they have been the object of interest for many plant virologists. They were also included in several ICTV Reports as well as in some handbooks concerning plant virology

Transport virusa M kartofelja v porazhjonnykh rastenijakh

Testem serologicznym wykryto wirus M ziemniaka (PVM) nawet w roślinach pomidora odmiany Najwcześniejszy, z których inokulowane liście usunięto już w 4 dni po inokulacji, choć ilość wirusa w roślinach, z których inokulowane liście usuwano, nieco później była większa. Testując serologicznie liście pomidora odmiany Najwcześniejszy z różnych pięter roślin w kolejnych tygodniach po inokulacji PVM wykryto wirus - pierwszy raz po 3 tygodniach od inokulacji w liściach inokulowanych i położonych bezpośrednio nad nimi. W późniejszych terminach testowania wykrywano PVM we wszystkich liściach z wyjątkiem liści najmłodszych. Nie wykryto PVM w bulwach odmiany Irys zebranych z roślin inokulowanych wirusem po 54 dniach od posadzenia, ani w roślinach wyrosłych z tych bulw. Liczba plamek lokalnych na liściach pierwotnych fasoli Red Kidney świadczy, że najwięcej PVM zawierały bulwy ze środkowej części pędów roślin odmiany Irys, inokulowanych wirusem po 33 dniach od posadzenia. Ilość wirusa w bulwach zawiązujących się później była mniejsza. Wyniki te potwierdziło badanie roślin wyrosłych z tych bulw.Путём серологической пробы обнаружен был вирус М картофеля (PVM) даже у растений помидора Раннеспелый, из которых инокулированные листья удалялись уже через 4 дня после инокуляции, хотя число вируса в растениях, инокулированные листья у которых удалялись немного позже, было выше. Исследуя серологическим путём листья помидора Раннеспелый из разных ярусов растения, на очередной неделе после иноулировки PVM, обнаружен был вирус уже через 3 недели после инокулировки в инокулированных листьях и в листьях расположенных непосредственно над ними. В более поздние сроки исследований PVM обнаружен был во всех листьях за исключением наиболее молодых листьев. Не обнаружен был рѵм ни в клубнях картофеля сорта Irys, выращенного из растений инокулированных вирусом в 54 дня после посадки, ни в растенях выросших из этих клубней. Число эндѳнѳмичѳских пятнышек полученных на первичных листьях фасоли Red Kidney свидетельствует, что больше всего PVM содержали клубни средней части побегов растений картофеля сорта Irys, инокулированных вирусом в 33 дня после посадки. Число вируса в клубнях завязывающихся позже, было меньше. Результаты эти были подтверждены исследованиями растений, выросших из этих клубней

Vyjavlenie viroida gotiki klubnejj kartofelja v 7 sortakh kartofelja vo vremja pervichnojj i vtorichnojj infekcii

W fazie pierwotnego porażenia na roślinach 7 odmian ziemniaka inokulowanych ostrym (s-PSTV) lub łagodnym (M-PSTV) izolatem wiroida wrzecionowatości bulw nie zaobserwowano żadnych objawów choroby. Łagodny izolat był wykrywany testem biologicznym na roślinach pomidora odm. Rutgers i przez elektroforezę ekstraktów kwasów nukleinowych na 5% żelu poliakrylamidowym u wszystkich odmian w 4 do 6 tygodni po inokulacji, natomiast ostry izolat wykrywano nieco później, a w roślinach niektórych odmian nie wykryto go aż do 9 tygodnia po inokulacji, W fazie wtórnego porażenia, to znaczy na roślinach wyrosłych z bulw zebranych z roślin inokulowanych oraz na bulwach zawiązanych przez te rośliny zaobserwowano typowe objawy porażenia PSTV. Łagodny izolat wykryto w 85% tych roślin, natomiast ostry - tylko w 58% tych roślin. W żadnej z roślin odmiany Pola nie wykryto s-PSTV, mimo iż objawy choroby były widoczne na roślinach i na bulwach. Słabszy był również poziom wykrywania s-PSTV w roślinach odmian Dryf i Sokół. Oba izolaty wiroida wykrywano w liściach, miąższu bulw oraz w oczkach i kiełkach, jak również w liściach z różnych pięter i w różnych pędach tej samej rośliny. Gorsze wyniki wykrywania s-PSTV i tym. razem były spowodowane złymi wynikami dla roślin odmian Dryf, Sokół i zwłaszcza Pola.В фазе первичного поражения на растениях семи сортов картофеля инокулированных острым (S-PSTV) либо мягким (M-PSTV) изолятом вироида готики картофеля (вѳретеновидности) не замечалось никаких признаков болезни. Мягкий изолят определяли (путём биологического теста на растениях помидора сорта ЕігЬеега и путём электрофореза экстрактов нуклеиновых кислот на 5% гель полиакриламид) в растениях всех сортов на 4 - 6 неделе после инокулировки. Острый изолят обнаружен был немного посже, а в растениях некоторых сортов не обнаружен был вообще до 9 недели после инокулировки. В фазе вторичного поражения т.е. на растениях выросших из собраных растений а также на клубнях завязанных этими растениями наблюдались типичные признаки поражения PSTV. Мягкий изолят был обнаружен у 85% этих растений, тогда как острый изолят выявлен был лишь у 58% этих растений. Ни в одном ив растений сорта Роlа не обнаружен был S-PSTV несмотря на то, что признаки болезни заметны были, как на растениях, так и на клубнях. Слаб тоже уровень выявления S-PSTV у растений сортов Dryft И Sokół. Оба изолята вироида обнаруживались в листьях, мякоти клубней, в глазках и проростках, а также в листьях разных ярусов и в разных побегах того же растения. Хуже давались обнаружить S-PSTV и в этом случае были вызваны плохими результатами для растений сортов Dryft, Sokół и особенно Роlа