Retrofit of a Rubotherm ISOSORP® 2000 for PVT-x and sorption measurements at cryogenic temperatures

Type V composite storage tanks have significantly increased the working pressures of cryogenic systems for aerospace applications. However, the current operating pressures often exceed the range of available mixture property models and measurements. The majority of cryogenic mixture property measurements are historical, having not been reviewed in over 40 years, which represents a growing problem. This paper describes the retrofit of an established Rubotherm ISOSORP® 2000 dual-sinker densimeter for cryogenic service. Design of a cryostat with vibration-isolation bellows to minimize vibration from the pulse-tube cryocooler is presented. Parasitic heat load calculations are provided to estimate the minimum operating temperature. The system is capable of achieving pressure up to 30 MPa. The design and anticipated capabilities of the experimental system are described.I.A. Richardson, T.M. Blackham, J.W. Leachman, and S.G. Penoncello, Retrofit of a Rubotherm Isosorp 2000 for PVT-x and Sorption Measurements at Cryogenic Temperatures, Transactions of the Cryogenic Engineering Conference, CEC: Advances in Cryogenic Engineering,1573 (2014), 1086

Development and Dosimetric Characterization of a Customizable Shield for Subtotal Skin Electron Beam Therapy

Purpose: Purpose: Subtotal skin electron beam therapy may be an option for patients with cutaneous lymphoma receiving radiation therapy to treat large areas of their skin but may benefit from sparing specific areas that may have had previous radiation therapy, are of specific cosmetic concern, and/or show no evidence of disease. We report here on the design, implementation, and dosimetric characteristics of a reusable and transparent customizable shield for use with the large fields used to deliver total skin electron beam therapy at extended distance with a conventional linear accelerator. Methods and Materials: A shield was designed and manufactured consisting of acrylic blocks that can be mounted on a steel frame to allow patient-specific shielding. The dosimetry of the device was measured using radiochromic film. Results: The shield is easy to use and well-tolerated for patient treatment, providing minimal electron transmission through the shield with a sharp penumbra at the field edge, with no increase in x-ray dose. We report on the dosimetry of a commercial device that has been used to treat more than 30 patients to date. Conclusions: The customizable shield is well suited to providing patient-specific shielding for subtotal skin electron beam therapy