222Rn emanation measurements for the XENON1T experiment

The selection of low-radioactive construction materials is of utmost importance for the success of low-energy rare event search experiments. Besides radioactive contaminants in the bulk, the emanation of radioactive radon atoms from material surfaces attains increasing relevance in the effort to further reduce the background of such experiments. In this work, we present the 222Rn emanation measurements performed for the XENON1T dark matter experiment. Together with the bulk impurity screening campaign, the results enabled us to select the radio-purest construction materials, targeting a 222Rn activity concentration of 10μBq/kg in 3.2t of xenon. The knowledge of the distribution of the 222Rn sources allowed us to selectively eliminate problematic components in the course of the experiment. The predictions from the emanation measurements were compared to data of the 222Rn activity concentration in XENON1T. The final 222Rn activity concentration of (4.5±0.1)μBq/kg in the target of XENON1T is the lowest ever achieved in a xenon dark matter experiment

Search for Electronic Recoil Event Rate Modulation with 4 Years of XENON100 Data

We report on a search for electronic recoil event rate modulation signatures in the XENON100 data accumulated over a period of 4 yr, from January 2010 to January 2014. A profile likelihood method, which incorporates the stability of the XENON100 detector and the known electronic recoil background model, is used to quantify the significance of periodicity in the time distribution of events. There is a weak modulation signature at a period of $431^{+16}_{−14}$ day in the low energy region of (2.0–5.8) keV in the single scatter event sample, with a global significance of 1.9$\sigma$; however, no other more significant modulation is observed. The significance of an annual modulation signature drops from 2.8$\sigma$, from a previous analysis of a subset of this data, to 1.8$\sigma$ with all data combined. Single scatter events in the low energy region are thus used to exclude the DAMA/LIBRA annual modulation as being due to dark matter electron interactions via axial vector coupling at 5.7$\sigma$

Online 222Rn^{222}Rn removal by cryogenic distillation in the XENON100 experiment

We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column was integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant $^{222}Rn$ background originating from radon emanation. After inserting an auxiliary $^{222}Rn$ emanation source in the gas loop, we determined a radon reduction factor of $R\,>\,27$ (95% C.L.) for the distillation column by monitoring the $^{222}Rn$ activity concentration inside the XENON100 detector

Material radiopurity control in the XENONnT experiment

The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and $^{222}Rn$ emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background (∼17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected $^{222}Rn$ activity concentration in XENONnT is determined to be 4.2 $(^{+0.5}_{−0.7}) μBq/kg$, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system

Cytotoxic chemotherapy for incurable colorectal cancer: living with a PICC-line

<b>Aims.</b> (i) To determine which aspects of living with a peripherally inserted central catheter (PICC) line cause Modified de Gramont (MdG) patients most difficulty. (ii) To explore MdG patients' views of the PICC-line experience. (iii) To determine if patients view PICC-lines as a benefit or a burden when receiving ambulatory MdG chemotherapy. <b>Design.</b> A two-stage, descriptive study. <b>Methods.</b> Phase 1 comprised semi-structured interviews. Phase 2 surveyed the MdG population. Phase 1 interview data informed the Phase 2 questionnaire. The setting was a West of Scotland Cancer Care Centre and the sample was: Phase 1, a convenience sample of 10 MdG patients; Phase 2, 62 consecutive patients. <b>Results.</b> A response rate of 93·9% for Phase 2. The majority of PICC-line patients held favourable views towards having a PICC-line and adapted well with minimal disruption to daily life. Concerns were evident regarding coping at home with a PICC-line, chemotherapy spillage, dealing with complex information and the responsibility of patients/carers regarding PICC-line management. Patients preferred ambulatory chemotherapy to in-patient treatment. <b>Conclusions.</b> PICC-lines should be considered for more chemotherapy patients but service development is necessary to ensure individual needs are addressed. <b>Relevance to clinical practice.</b> Contributes to the PICC-line literature by providing a national patient perspective on a range of daily living activities (DLAs). PICC-line patients prefer out-patient ambulatory chemotherapy rather than in-patient treatment. The longer a patient has a PICC-line, the more able they are to manage activities such as dressing. Concerns remain over chemotherapy spillage, partner/carer responsibility for PICC-line maintenance and the proper balance between required information and what the patient wants to know

Denitrification and nitrous oxide emissions from riparian forests soils exposed to prolonged nitrogen runoff

Compared to upland forests, riparian forest soils have greater potential to remove nitrate (NO3) from agricultural run-off through denitrification. It is unclear, however, whether prolonged exposure of riparian soils to nitrogen (N) loading will affect the rate of denitrification and its end products. This research assesses the rate of denitrification and nitrous oxide (N2O) emissions from riparian forest soils exposed to prolonged nutrient run-off from plant nurseries and compares these to similar forest soils not exposed to nutrient run-off. Nursery run-off also contains high levels of phosphate (PO4). Since there are conflicting reports on the impact of PO4 on the activity of denitrifying microbes, the impact of PO4 on such activity was also investigated. Bulk and intact soil cores were collected from N-exposed and non-exposed forests to determine denitrification and N2O emission rates, whereas denitrification potential was determined using soil slurries. Compared to the non-amended treatment, denitrification rate increased 2.7- and 3.4-fold when soil cores collected from both N-exposed and non-exposed sites were amended with 30 and 60 μg NO3-N g-1 soil, respectively. Net N2O emissions were 1.5 and 1.7 times higher from the N-exposed sites compared to the non-exposed sites at 30 and 60 μg NO3-N g-1 soil amendment rates, respectively. Similarly, denitrification potential increased 17 times in response to addition of 15 μg NO3-N g-1 in soil slurries. The addition of PO4 (5 μg PO4–P g-1) to soil slurries and intact cores did not affect denitrification rates. These observations suggest that prolonged N loading did not affect the denitrification potential of the riparian forest soils; however, it did result in higher N2O emissions compared to emission rates from non-exposed forests

Erratum: First axion results from the XENON100 experiment [Phys. Rev. D 90, 062009 (2014)]

n our paper, we presented searches for solar axions and galactic axionlike particles (ALPs) in the data collected by the XENON100 experiment (with an exposure of 224.6 days). We recently found a bug in the code to calculate the exclusion limit for galactic ALPs. This resulted in an underestimation of the ALP expected rate, which in turn led to an overly conservative limit, compared to what it should really be. We corrected the code, and the result of the XENON100 90% C.L. exclusion limit on galactic ALPs (shown in Fig. 1) was reevaluated. The corrected limit is stronger than the one previously published by approximately a factor of 5 across all masses and sets the best published limit on the axion-electron coupling, $g_{Ae}$, in the (1–40)  keV/$c^2$ mass range

Stationary Black Holes: Uniqueness and Beyond

The spectrum of known black-hole solutions to the stationary Einstein equations has been steadily increasing, sometimes in unexpected ways. In particular, it has turned out that not all black-hole-equilibrium configurations are characterized by their mass, angular momentum and global charges. Moreover, the high degree of symmetry displayed by vacuum and electro-vacuum black-hole spacetimes ceases to exist in self-gravitating non-linear field theories. This text aims to review some developments in the subject and to discuss them in light of the uniqueness theorem for the Einstein-Maxwell system.Comment: Major update of the original version by Markus Heusler from 1998. Piotr T. Chru\'sciel and Jo\~ao Lopes Costa succeeded to this review's authorship. Significantly restructured and updated all sections; changes are too numerous to be usefully described here. The number of references increased from 186 to 32