Addendum to NuMI shielding assessment

The original safety assessment and the Safety Envelope for the NuMI beam line corresponds to 400 kW of beam power. The Main Injector is currently capable of and approved for producing 500 kW of beam power2. However, operation of the NuMI beam line at 400 kW of power brings up the possibility of an occasional excursion above 400 kW due to better than usual tuning in one of the machines upstream of the NuMI beam line. An excursion above the DOE approved Safety Envelope will constitute a safety violation. The purpose of this addendum is to evaluate the radiological issues and modifications required to operate the NuMI beam line at 500 kW. This upgrade will allow 400 kW operations with a reasonable safety margin. Configuration of the NuMI beam line, boundaries, safety system and the methodologies used for the calculations are as described in the original NuMI SAD. While most of the calculations presented in the original shielding assessment were based on Monte Carlo simulations, which were based on the design geometries, most of the results presented in this addendum are based on the measurements conducted by the AD ES&H radiation safety group

Hilbert space of Quantum Field Theory in de Sitter spacetime

We study the decomposition of the Hilbert space of quantum field theory in $(d+1)$ dimensional de Sitter spacetime into Unitary Irreducible Representations (UIRs) of its isometry group \SO$(1,d+1)$. Firstly, we consider multi-particle states in free theories starting from the tensor product of single-particle UIRs. Secondly, we study conformal multiplets of a bulk Conformal Field Theory with symmetry group \SO$(2,d+1)$. Our main tools are the Harish-Chandra characters and the numerical diagonalization of the (truncated) quadratic Casimir of \SO$(1,d+1)$. We introduce a continuous density that encodes the spectrum of irreducible representations contained in a reducible one of \SO(1,d+1). Our results are complete for $d=1$ and $d=2$. In higher dimensions, we rederive and extend several results previously known in the literature. Our work provides the foundation for future nonperturbative bootstrap studies of Quantum Field Theory in de Sitter spacetime.Comment: 58 pages + appendices, 44 figures and 4 table

Neutron dose per fluence and weighting factors for use at high energy accelerators

In June 2007, the United States Department of Energy incorporated revised values of neutron weighting factors into its occupational radiation protection Regulation 10 CFR Part 835 as part of updating its radiation dosimetry system. This has led to a reassessment of neutron radiation fields at high energy proton accelerators such as those at the Fermi National Accelerator Laboratory (Fermilab). Values of dose per fluence factors appropriate for accelerator radiation fields calculated elsewhere are collated and radiation weighting factors compared. The results of this revision to the dosimetric system are applied to americium-beryllium neutron energy spectra commonly used for instrument calibrations. A set of typical accelerator neutron energy spectra previously measured at Fermilab are reassessed in light of the new dosimetry system. The implications of this revision are found to be of moderate significance

The K\"all\'en-Lehmann representation in de Sitter spacetime

We study two-point functions of symmetric traceless local operators in the bulk of de Sitter spacetime. We derive the K\"all\'en-Lehmann spectral decomposition for any spin and show that unitarity implies its spectral densities are nonnegative. In addition, we recover the K\"all\'en-Lehmann decomposition in Minkowski space by taking the flat space limit. Using harmonic analysis and the Wick rotation to Euclidean Anti de Sitter, we derive an inversion formula to compute the spectral densities. Using the inversion formula, we relate the analytic structure of the spectral densities to the late-time boundary operator content. We apply our technical tools to study two-point functions of composite operators in free and weakly coupled theories. In the weakly coupled case, we show how the K\"all\'en-Lehmann decomposition is useful to find the anomalous dimensions of the late-time boundary operators. We also derive the K\"all\'en-Lehmann representation of two-point functions of spinning primary operators of a Conformal Field Theory on de Sitter.Comment: 62 pages + appendices, 10 figure

To be published in Health Physics

ABSTRACT In June 2007, the United States Department of Energy incorporated revised values of neutron weighting factors into its occupational radiation protection regulation Title 10, Code of Federal Regulations Part 835 as part of updating its radiation dosimetry system. This has led to a reassessment of neutron radiation fields at high energy accelerators such as those at the Fermi National Accelerator Laboratory (Fermilab) in the context of the amended regulation and contemporary guidance of the International Commission on Radiological Protection. Values of dose per fluence factors appropriate for accelerator radiation fields calculated elsewhere are collated and radiation weighting factors compared. The results of this revision to the dosimetric system are applied to americium-beryllium neutron energy spectra commonly used for instrument calibrations. Also, a set of typical accelerator neutron energy spectra previously measured at Fermilab are reassessed in light of the new dosimetry system. The implications of this revision and of recent ICRP publications are found to be of moderate significance

Control of Prompt Radiation Hazards at Accelerator Facilities

Recently some interest has been aroused over the early draft of a document written by a sub-committee from the Accelerator Section of the Health Physics Society entitled: The Control of Prompt Radiation Hazards at Accelerator Facilities. This article picks out some of the salient pieces of that draft to show the thinking of the authors and the possible shape of the revised document

Knowledge and perception toward colorectal cancer screening in east of Iran

Background: Colorectal Cancer (CRC) is the third most common cancer in Iran and its early detection is necessary. This study is based on perception of people in the east of Iran toward CRC screening. Methods: In a cross-sectional study, 1060 randomly selected individuals who referred to Razavi Hospital of Mashhad, Iran, between September the 1 st , 2012 and February the 28 th , 2013 as patients or their visitors involved in an interview to fill a questionnaire on CRC screening. Results: The participants’ age ranged from 40 to 88 years (mean= 55). More than 90% had no knowledge of CRC and screening tests. The most cited reasons for not having screening tests were “did not have any problem” and “did not think it was needed”. Although, older people had more knowledge of CRC ( P = 0.033), there was no relationship between gender, health insurance status, family history of individuals and their knowledge about CRC ( P > 0.050). Employment, education and higher income had positive effect on the perception of people toward CRC screening ( P < 0.050). Conclusion: Lack of knowledge in people in lower socio-economical class with limited literacy is the most important barrier to CRC screening. As such, designing educational programs involving physicians and media is important to improve CRC screening rates