A large number of particle detectors employ liquid argon as their target material owing to its high scintillation yield and its ability to drift ionization charge over large distances. Scintillation ...light from argon is peaked at 128 nm and a wavelength shifter is required for its efficient detection. In this work, we directly compare the light yield achieved in two identical liquid argon chambers, one of which is equipped with polyethylene naphthalate (PEN) and the other with tetraphenyl butadiene (TPB) wavelength shifter. Both chambers are lined with enhanced specular reflectors and instrumented with SiPMs with a coverage fraction of approximately 1%, which represents a geometry comparable to the future large scale detectors. We measured the light yield of the PEN chamber to be 39.4
±
0.4(stat)
±
1.9(syst)% of the yield of the TPB chamber. Using a Monte Carlo simulation this result is used to extract the wavelength shifting efficiency of PEN relative to TPB equal to 47.2
±
5.7%. This result paves the way for the use of easily available PEN foils as a wavelength shifter, which can substantially simplify the construction of future liquid argon detectors.
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Abstract Polyethylene naphthalate (PEN) foils have been demonstrated as a wavelength shifter suitable for operation in liquid argon. At the same time, wavelength shifting efficiency of technical ...grades of PEN, commercially available on the market, is lower than that of tetraphenyl butadiene (TPB). This paper reports on an R&D program focused on exploring the intrinsic limitations of PEN and optimizing it for the highest achievable wavelength shifting efficiency.
A new concept for the simultaneous detection of primary and secondary scintillation in time projection chambers is proposed. Its core element is a type of very-thick GEM structure supplied with ...transparent electrodes and machined from a polyethylene naphthalate plate, a natural wavelength shifter. Such a device has good prospects for scalability and, by virtue of its genuine optical properties, it can improve on the light collection efficiency, energy threshold and resolution of conventional micropattern gas detectors. This, together with the intrinsic radiopurity of its constituting elements, offers advantages for noble gas and liquid based time projection chambers, used for dark matter searches and neutrino experiments. Production, optical and electrical characterization, and first measurements performed with the new device are reported.
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Polyethylene naphthalate (PEN) foils have been demonstrated as a wavelength shifter suitable for operation in liquid argon. At the same time, wavelength shifting efficiency of technical grades of ...PEN, commercially available on the market, is lower than that of tetraphenyl butadiene (TPB). This paper reports on an R&D program focused on exploring the intrinsic limitations of PEN and optimizing it for the highest achievable wavelength shifting efficiency.
A new concept for the simultaneous detection of primary and secondary scintillation in time projection chambers is proposed. Its core element is a type of very-thick GEM structure supplied with ...transparent electrodes and machined from a polyethylene naphthalate plate, a natural wavelength-shifter. Such a device has good prospects for scalability and, by virtue of its genuine optical properties, it can improve on the light collection efficiency, energy threshold and resolution of conventional micropattern gas detectors. This, together with the intrinsic radiopurity of its constituting elements, offers advantages for noble gas and liquid based time projection chambers, used for dark matter searches and neutrino experiments. Production, optical and electrical characterization, and first measurements performed with the new device are reported.
A large number of particle detectors employ liquid argon as their target material owing to its high scintillation yield and its ability to drift ionization charge over large distances. Scintillation ...light from argon is peaked at 128 nm and a wavelength shifter is required for its efficient detection. In this work, we directly compare the light yield achieved in two identical liquid argon chambers, one of which is equipped with PolyEthylene Naphthalate (PEN) and the other with TetraPhenyl Butadiene (TPB) wavelength shifter. Both chambers are lined with enhanced specular reflectors and instrumented with SiPMs with a coverage fraction of approximately 1%, which represents a geometry comparable to the future large scale detectors. We measured the light yield of the PEN chamber to be 39.4\(\pm\)0.4(stat)\(\pm\)1.9(syst)% of the yield of the TPB chamber. Using a Monte Carlo simulation this result is used to extract the wavelength shifting efficiency of PEN relative to TPB equal to 47.2\(\pm\)5.7%. This result paves the way for the use of easily available PEN foils as a wavelength shifter, which can substantially simplify the construction of future liquid argon detectors.
Artykuł poświęcony jest próbie odpowiedzi na pytanie: w jakim stopniu konflikt ostatnich kilkunastu lat w Polsce, funkcjonujący w dyskursie społecznym i publicystyce jako „wojna polsko-polska”, ...spełnia modelowe warunki uprawniające do określania go mianem „wojny domowej”? Jako model tego typu starcia wybrano opis wojny domowej w Korkirze. Zdecydowano się na tę perspektywę z dwu powodów; pierwszy – bo pozwala przedstawić problem podobnego konfliktu sine ira et studio. Drugi – w tym samym duchu – pozwala przedyskutować problem statusu poznawczego „zaangażowanego obserwatora” w spolaryzowanym społeczeństwie, a więc także takie kwestie jak obiektywizm, stronniczość czy – tak szeroko dyskutowany w przestrzeni medialnej ostatnich lat – symetryzm. Niniejszy artykuł jest próbą sprawdzenia sensowności pewnego typu analitycznego podejścia do rozumienia silnie spolaryzowanej współczesności. Szczególnym układem odniesienia pozostaje tu interpretacja przyjętych za modelowe przypadków historycznych. Za wyborem takiej właśnie perspektywy zdaje się przemawiać nie tylko możliwość ukazania istotnych socjologicznie, a trwałych konturów interpretowanego zjawiska. Jej zaleta tkwi także w możliwości zdystansowania się od nasyconego emocjami dyskursu aktualnych politycznych sporów.
Artykuł poświęcony jest socjologicznym aspektom interpretacji szczególnego rodzaju tekstów. Ich autorami/autorkami są „ludzie pióra” – pisarze, publicyści itp. Same zaś teksty (głównie literatura ...dokumentu osobistego, acz nie tylko) nie aspirują do formy powieściowej czy innej wersji fikcji literackiej; jednak autorzy/autorki wykorzystują w nich z pełną świadomością środki stylistyki literackiej i – szerzej – retorycznej. Charakteryzowane w artykule materiały traktowane są jako komunikaty i „występy”. Przyjęto bowiem, że każdy zapoczątkowany przez nadawcę akt komunikowania (a więc także tekst) jest próbą występu w Goffmanowskim rozumieniu tego pojęcia. Artykuł wychodzi od interpretacji proponowanej w eseju Clifforda Geertza, poprzez przypomnienie szans, jakie stwarza poszukiwaniom z zakresu socjologii jakościowej metoda konstruktywna Jana Szczepańskiego, a także niektóre – podane z interpretacyjnymi przykładami – aspekty koncepcji Leo Straussa czy Umberto Eco. Na przykładzie zarysów kilku przykładów historycznych, ale także bardziej współczesnych ilustracji artykuł ma na celu uczulenie socjologicznych interpretatorów na specyfikę analizowanego, a bardziej – niż zwykle się to dzieje – złożonego kontekstualnie i retorycznie występu (w tym tekstu czy innej formy komunikatu). Choć w założeniu opracowanie to ma przede wszystkim wspomóc badawcze zainteresowania tekstami przynależnymi do literatury dokumentu osobistego „ludzi pióra”, to ma on także ambicje – gdy idzie o socjologiczną interpretację Goffmanowskich występów – bardziej ogólne.
The presented work is an attempt to look at Thucydides’s History of the Pelo¬ponnesian War from a very special point of view — from the perspective of a so¬ciologist of literature. Such a monograph ...can be imagined in several ways. In the variant proposed here, it tries to be, on the one hand, a sociological (not military, but indeed a sociological) reconstruction of a model of the internally and exter¬nally conflicted world of Greek polis, just as it is presented along with its prob¬lems by the Athenian historian, and on the other hand, a very personal study of the reading of Thucydides’ work. The combination of both tasks compels the au¬thor to create an amalgam of an analysis, interpretation, quasi-guide to the His¬tory of the Peloponnesian War and essay (but in an academic, non-literary sense). The author also intends this work to indicate the contexts in which Thucydides’s work can be interpreted in a broader way since for the sociologist of literature it is a bit different than from that of a historian, political scientist, political philoso¬pher or specialist in the theory of international political relations.
Exfoliated g-C3N4 is a well-known semiconductor utilized in heterogenous photocatalysis and water splitting. An improvement in light harvesting and separation of photogenerated charge carriers may be ...obtained by polymer doping with sulfur. In this work, we incorporate sulfur into the polymer chain by chemical polymerization of trithiocyanuric acid (C3N3S3H3) to obtain C3N3S3. The XRD measurements and TEM images indicated that C3N3S3, in contrast to g-C3N4, does not exist in the form of a graphitic structure and is not exfoliated into thin lamellas. However, both polymers have similar optical properties and positions of the conduction and valence bands. The comparative studies of electrochemical oxygen reduction and hydrogen evolution indicated that the overpotentials for the two processes were smaller for C3N3S3 than for g-C3N4. The RDE experiments in the oxygen-saturated solutions of 0.1 M NaOH have shown that O2 is electrochemically reduced via the serial pathway with two electrons involved in the first step. The spectroscopic experiments using NBT demonstrated that both polymers reveal high activity in the photocatalytic reduction of oxygen to superoxide anion radical by the photogenerated electrons.
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