Strontium and calcium in foodstuffs

U referatu je dat općeniti pregled načina kontaminacije biljaka radioaktivnim elementima. Posebna pažnja posvećena je kontaminaciji biljaka radioaktivnim stroncijem. Interpretirani su rezultati analize nekih prehrambenih artikala biljnog porijekla i stočne hrane.In 1962 and 1963 determination of Sr-90 and Ca in some foodstuffs and fodder of vegetable origin was carried out. Analysis of the results obtained has led to the following conclusions: 1. Grass (hay, lucerne) is for the most part contaminated by surface contamination. 2. The degree of surface contamination of hay and lucerne is comparatively higher in spring than in summer vegetation owing to a higher radioactive fallout in spring. 3. The activity of lucerne is somewhat lower than the activity of hay because the roots of lucerne go deeper into the soil and are therefore less exposed to indirect contamination. 4. The plants with a lower Ca content take a proportionately lower content of Sr-90 from the soil. This is extremely important for the articles contaminated through the soil, because the amount of strontium and calcium taken by the plant from the soil is in an approximate relation to the amount of these elements dissolved in the soil

Sensor Development for the Large Synoptic Survey Telescope.

The Large Synoptic Survey project proposes to build an 8m-class ground-based telescope with a dedicated wide field camera. The camera consists of a large focal plane mosaic composed of multi-output CCDs with extended red response. Design considerations and preliminary characterization results for the sensors are presented in this contribution to the Workshop

Monolithic front-end preamplifiers for a broad range of calorimetry applications

The present paper summarizes the salient results of a research and development activity in the area of low noise preamplifiers for different applications in calorimetry. Design target for all circuits considered here are low noise, ability to cope with broad energy ranges and radiation hardness

Determination of the apparent age of nuclear explosions

Određena je prividna dob nuklearne eksplozije pretpostavljajući da se izmjerena aktivnost od više eksplozija može uzeti kao da je nastala samo od jedne nuklearne eksplozije.The apparent age of a nuclear explosion is determined by a well known formula, assuming the observed activity can be characterized as that resulting from a single nuclear detonation

Optically Based Charge Injection System for Ionization Detectors

An optically coupled charge injection system for ionization based radiation detectors which allows a test charge to be injected without the creation of ground loops has been developed. An ionization like signal from an external source is brought into the detector through an optical fiber and injected into the electrodes by means of a photodiode. As an application example, crosstalk measurements on a liquid Argon electromagnetic calorimeter readout electrodes were performed

Developments of a 2D Position Sensitive Neutron Detector

Chinese Spallation Neutron Source (CSNS), one project of the 12th five-year-plan scheme of China, is under construction in Guangdong province. Three neutron spectrometers will be installed at the first phase of the project, where two-dimensional position sensitive thermal neutron detectors are required. Before the construction of the neutron detector, a prototype of two-dimensional 200 mmx200 mm Multi-wire Proportional Chamber (MWPC) with the flowing gas of Ar/CO2 (90/10) has been constructed and tested with the 55Fe X-Ray using part of the electronics in 2009, which showed a good performance. Following the test in 2009, the neutron detector has been constructed with the complete electronics and filled with the 6atm.3He + 2.5atm.C3H8 gas mixture in 2010. The neutron detector has been primarily tested with an Am/Be source. In this paper, some new developments of the neutron detector including the design of the high pressure chamber, the optimization of the gas purifying system and the gas filling process will be reported. The results and discussion are also presented in this paper.Comment: 5 page