LNL Annual Report 2008
نویسندگان
چکیده
The MSAC is a stack of grids that gives rise, when biased at high voltage, to four planar gas proportional counters connected each other. In spite of the low gas gain of each counter (about 100), the final gain can easily overcome 10. Thanks to such high gain, the MSAC can detect single electrons by using fast front-end electronics to process the current arisen from the last grid when a single electron enters into the first grid. The MSAC has to fulfil many requirements. First, the distance between adjacent grids (dgrid) must be as little as possible (few millimeters) in order to maximize the electron field intensity at the minimum voltage. In fact in STARTRACK experiment, MSAC detector operates at 3 mbar of propane gas, that is the value of minimum of the Paschen discharge curve. To the upper grid of MSAC is applied the highest voltage, which consequently can not exceed 800 V. Secondary, grid planarity uncertainties should be lower than 20% of dgrid, in order to guarantee position independency of the counting efficiency.
منابع مشابه
LNL Annual Report 2008
SRAM-based Field Programmable Gate Arrays (FPGAs) are an attractive solution for many applications where short time-to-market, low-cost for low-production volumes, and in-the-field-programming ability are important issues. One of the few major disadvantages of SRAM-based FPGAs is the sensitivity to ionizing radiation [1-3]. Indeed, also at sea level, neutrons, originating from the interactions ...
متن کاملLNL Annual Report 2004
In the framework of the Italian BNCT research program, the low-power (5 kW), fast-flux, TAPIRO research reactor, located at the ENEA Casaccia Centre near Rome, is foreseen to be implemented as the national facility devoted to supply an epithermal neutron beam required for malignant brain tumor treatment[1]. The feasibility to provide both thermal and epithermal suitable neutron beams in the mai...
متن کاملA Cointuitionistic Adjoint Logic
Bi-intuitionistic logic (BINT) is a conservative extension of intuitionistic logic to include the duals of each logical connective. One leading question with respect to BINT is, what does BINT look like across the three arcs – logic, typed λ-calculi, and category theory – of the Curry-HowardLambek correspondence? Categorically, BINT can be seen as a mixing of two worlds: the first being intuiti...
متن کاملProgress Towards Bonner Sphere Spectrometry of the INFN-LNL SPES-BNCT
The Legnaro National Laboratories (LNL) of the Italian National Institute of Nuclear Physics (INFN) are developing a neutron source within the SPES-BNCT project. An accelerator-based, high-flux thermal neutron beam facility is planned for the experimental treatment of skin melanoma. Neutrons are produced via the Be(p,n) reaction by bombarding a 1 mm thick beryllium target with 5 MeV protons gen...
متن کاملSuppressor cell activity in melanoma-draining lymph nodes.
We previously demonstrated that the cells of lymph nodes near to a melanoma respond well to stimulation by mitogens, alloantigens, and interleukin 2 than do nodes further away. In this study we examined suppressor T-cell activity in nodes at different distances from primary melanoma, using a concanavalin A (Con A) suppressor cell assay. Tumor-free regional nodes were classified as proximal, int...
متن کامل