Micromegas探测器计数曲线、增益以及能量分辨特性的研究

介绍了自行研制的Micromegas探测器的基本结构和工作原理.在不同工作气体(Ar和CO2)配比条件下,利用55Fe放射源对该探测器的能量分辨、计数曲线和气体增益等特性进行了较为详尽的测试.对相关结果进行了讨论.

利用Garfield程序模拟Micromegas探测器增益和位置分辨特性(英文)

利用Garfield气体探测器模拟程序模拟了不同条件下Micromegas探测器的增益和位置分辨特性.通过对模拟结果的分析,得出提高探测器位置分辨和增益的有效途径.该工作不仅可以优化气体探测器结构设计,缩短实验周期,而且还能极大程度的节约经费.

Monte Carlo studies of micromegas as a neutron detector and its track reconstruction

In this paper a two dimensional readout micromegas detector with a polyethylene foil as converter was simulated on GEANT4 toolkit and GARFIELD for fast neutron detection. A new track reconstruction method based on time coincidence technology was developed in the simulation to obtain the incident neutron position. The results showed that with this reconstruction method higher spatial resolution was achieved.

Micromegas探测器计数曲线、增益以及能量分辨特性的研究

介绍了自行研制的Micromegas探测器的基本结构和工作原理. 在不同工作气体(Ar和CO2)配比条件下，利用55Fe放射源对该探测器的能量分辨、计数曲线和气体增益等特性进行了较为详尽的测试. 对相关结果进行了讨论.

The time and energy signals, counter plateau, energy resolution and gas gains performances of a new kind of micro-pattern gaseous detector-Micromegas

In present paper, a new Micromegas detector is developed, and its time and energy signals are obtained in the figure form. The rising time of fast time signal is less than 2 ns due to the very fast collection of avalanche electrons, and the rising time of the energy pulse is about 100 ns, which is corresponding to the total collecting time of the electrons and ions in the avalanche process. The counter plateau, energy resolution and the gas gains of the detector have been compared with other groups' experimental results and the Garfield simulation result.

Simulation of micromegas detector by garfield program

In this paper, a batch file which describes the detailed structure and the corresponding physical process of Micro-Mesh Gaseous Structure (Micromegas) detector, the macro commands and the control structures based on the Garfield program has been developed. And using the Garfield program controlled by this batch file, the detector's gain and spatial resolution have been investigated under different conditions. These results obtained by the simulation program not only exhibit the influences of the mesh and drift voltage, the mixture gas proportion, the distance between the mesh cathode and the printed circuit board readout anode, and the Lines Per Inch of the mesh cathode on the gain and spatial resolution of the detector, but also are very important to optimize the design, shorten the experimental period, and save cost during the detector development. Additionally, they also indicate that the Garfield program is a powerful tool for the Micromegas detector design and optimization.

Oeuvres de Voltaire,

Romans. v. 1. Le monde comme il va. Le crocheteur borgne. Cosi-sancta. Zadig. Bababec. Micromegas. Les deux consoles. Histoire des voyages de Scarmentado.Songe de Platon. Histoire d'un bon Bramin.- v. 2. Candide.Le blanc et le noir. Jeannot et Colin. L'Ingenu. L'Homme aux quarante ecus.- v. 3. La princesse de Babylone.Les lettres d'Amabed. Aventure de la memoire. Le taureau blanc. Eloge de la raison. Histoire de Jenni. Les oreilles du comte de Chesterfield.

"Paseo por una guerra antigua" (Juan Antonio Bardem, 1948-49): una contramemoria de la Guerra Civil

Este artículo pretende demostrar en qué medida Paseo por una guerra antigua (1948-1949), la práctica de segundo curso del Instituto de Investigaciones y Experiencias Cinematográficas (IIEC) en la que Juan Antonio Bardem rueda a un joven mutilado caminando por las ruinas de la Ciudad Universitaria de Madrid, constituye un intento pionero de desmontar los relatos oficiales de la Guerra Civil Española y rescatar la memoria de los vencidos. Filmar las ruinas del campus madrileño en aquellos años era un acto sub­versivo, puesto que el Régimen había emprendido su reconstrucción para borrar las huellas del Madrid republicano y de la Guerra Civil, resignificando por completo el recinto universitario. Por tanto, en Paseo por una guerra antigua, Bardem intenta reapropiarse de un espacio que en la época iba imponiéndose como uno de los “lugares de memoria” del franquismo. Esta película se vale de la función documental del cine para inmortalizar unas ruinas que simbolizan la República y la guerra, para preservarlas de la muerte simbólica que representa su reconstrucción. Mostrar esas ruinas en 1948-1949 equivale a “materializar” el pasado, a traerlo al presente de la posguerra, en un proceso que recuerda a los planteamientos sobre la Historia de Walter Benjamin, para proponer una visión alternativa de la contienda. Se trata de una visión teñida de una memoria íntima, ya que la película es un paseo no solo por las ruinas sino también por los recuerdos de este joven mutilado. En suma, Bardem propone una contramemoria de la Guerra Civil.

Study and development of UV photodetectors envisaging COMPASS RICH-1 upgrade and applications

COMPASS is an experiment at CERN’s SPS whose goal is to study hadron structure and spectroscopy. The experiment includes a wide acceptance RICH detector, operating since 2001 and subject to a major upgrade of the central region of its photodetectors in 2006. The remaining 75% of the photodetection area are still using MWPCs from the original design, who suffer from limitations in gain due to aging of the photocathodes from ion bombardment and due to ion-induced instabilities. Besides the mentioned limitations, the increased luminosity conditions expected for the upcoming years of the experiment make an upgrade to the remaining detectors pertinent. This upgrade should be accomplished in 2016, using hybrid detectors composed of ThGEMs and MICROMEGAS. This work presents the study, development and characterization of gaseous photon detectors envisaging the foreseen upgrade, and the progress in production and evaluation techniques necessary to reach increasingly larger area detectors with the performances required. It includes reports on the studies performed under particle beam environment of such detectors. MPGD structures can also be used in a variety of other applications, of which nuclear medical imaging is a notorious example. This work includes, additionally, the initial steps in simulating, assembling and characterizing a prototype of a gaseous detector for application as a Compton Camera.