Effect of the ohmic drop in a RPC-like chamber for measurements of electron transport parameters
The main advantage of Resistive Plate Chambers (RPCs), applied, for instance, in High-Energy Experiments and Positron Emission Tomography (PET), is that it is spark-protected due to the presence of, at least, one high-resistive electrode. However, the ohmic drop across the latter can affect the char...
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| Format: | Article |
| Language: | English |
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Brazilian Radiation Protection Society (Sociedade Brasileira de Proteção Radiológica, SBPR)
2019-02-01
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| Series: | Brazilian Journal of Radiation Sciences |
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| Online Access: | https://bjrs.org.br/revista/index.php/REVISTA/article/view/637 |
| _version_ | 1797985918516199424 |
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| author | Anna Raquel Petri |
| author_facet | Anna Raquel Petri |
| author_sort | Anna Raquel Petri |
| collection | DOAJ |
| description | The main advantage of Resistive Plate Chambers (RPCs), applied, for instance, in High-Energy Experiments and Positron Emission Tomography (PET), is that it is spark-protected due to the presence of, at least, one high-resistive electrode. However, the ohmic drop across the latter can affect the charge multiplication significantly. In this work, we investigate this effect in a RPC-like chamber. The counter was filled with nitrogen at atmospheric pressure and the primary ionization was produced by the incidence of nitrogen pulsed laser beam on an aluminum cathode. The illumination area of the cathode was measured using a foil of millimetric paper overlaid on this electrode. In this way, the resistance of the glass anode could be estimated using the known resistivity of the glass (ρ=2×1012 Ω.cm). Therefore, the voltage drop across the dielectric was calculated by the product of the current across the gas gap and the anode resistance. In order to mitigate the effect of the resistive electrode, the laser beam intensity was limited by interposing metallic meshes between the laser and the chamber window. The dependence of the ohmic drop from the applied voltage was analyzed. The results obtained shown that, without the meshes, the ohmic drop corresponds up to 7% of the applied voltage, preventing the detection system to reach values of density-normalized electric fields in the gas gap (Eeff/N) higher than 166 Td. By minimizing the laser beam intensity and, consequently, the primary ionization, the ohmic drop represented only 0.2% of the applied voltage, extending the Eeff /N range up to 175 Td.
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| first_indexed | 2024-04-11T07:25:30Z |
| format | Article |
| id | doaj.art-80d8444231dd46f3ae5fdbfb5b01651d |
| institution | Directory Open Access Journal |
| issn | 2319-0612 |
| language | English |
| last_indexed | 2024-04-11T07:25:30Z |
| publishDate | 2019-02-01 |
| publisher | Brazilian Radiation Protection Society (Sociedade Brasileira de Proteção Radiológica, SBPR) |
| record_format | Article |
| series | Brazilian Journal of Radiation Sciences |
| spelling | doaj.art-80d8444231dd46f3ae5fdbfb5b01651d2022-12-22T04:37:05ZengBrazilian Radiation Protection Society (Sociedade Brasileira de Proteção Radiológica, SBPR)Brazilian Journal of Radiation Sciences2319-06122019-02-0172A10.15392/bjrs.v7i2A.637Effect of the ohmic drop in a RPC-like chamber for measurements of electron transport parametersAnna Raquel Petri0Instítuto de Física - Universidade de São PauloThe main advantage of Resistive Plate Chambers (RPCs), applied, for instance, in High-Energy Experiments and Positron Emission Tomography (PET), is that it is spark-protected due to the presence of, at least, one high-resistive electrode. However, the ohmic drop across the latter can affect the charge multiplication significantly. In this work, we investigate this effect in a RPC-like chamber. The counter was filled with nitrogen at atmospheric pressure and the primary ionization was produced by the incidence of nitrogen pulsed laser beam on an aluminum cathode. The illumination area of the cathode was measured using a foil of millimetric paper overlaid on this electrode. In this way, the resistance of the glass anode could be estimated using the known resistivity of the glass (ρ=2×1012 Ω.cm). Therefore, the voltage drop across the dielectric was calculated by the product of the current across the gas gap and the anode resistance. In order to mitigate the effect of the resistive electrode, the laser beam intensity was limited by interposing metallic meshes between the laser and the chamber window. The dependence of the ohmic drop from the applied voltage was analyzed. The results obtained shown that, without the meshes, the ohmic drop corresponds up to 7% of the applied voltage, preventing the detection system to reach values of density-normalized electric fields in the gas gap (Eeff/N) higher than 166 Td. By minimizing the laser beam intensity and, consequently, the primary ionization, the ohmic drop represented only 0.2% of the applied voltage, extending the Eeff /N range up to 175 Td. https://bjrs.org.br/revista/index.php/REVISTA/article/view/637electron transport parametersRPC detectorsgaseous detectors |
| spellingShingle | Anna Raquel Petri Effect of the ohmic drop in a RPC-like chamber for measurements of electron transport parameters Brazilian Journal of Radiation Sciences electron transport parameters RPC detectors gaseous detectors |
| title | Effect of the ohmic drop in a RPC-like chamber for measurements of electron transport parameters |
| title_full | Effect of the ohmic drop in a RPC-like chamber for measurements of electron transport parameters |
| title_fullStr | Effect of the ohmic drop in a RPC-like chamber for measurements of electron transport parameters |
| title_full_unstemmed | Effect of the ohmic drop in a RPC-like chamber for measurements of electron transport parameters |
| title_short | Effect of the ohmic drop in a RPC-like chamber for measurements of electron transport parameters |
| title_sort | effect of the ohmic drop in a rpc like chamber for measurements of electron transport parameters |
| topic | electron transport parameters RPC detectors gaseous detectors |
| url | https://bjrs.org.br/revista/index.php/REVISTA/article/view/637 |
| work_keys_str_mv | AT annaraquelpetri effectoftheohmicdropinarpclikechamberformeasurementsofelectrontransportparameters |