{"id":111,"date":"2019-10-01T11:07:38","date_gmt":"2019-10-01T11:07:38","guid":{"rendered":"http:\/\/alice.phy.hr\/?page_id=111"},"modified":"2021-04-01T11:17:50","modified_gmt":"2021-04-01T11:17:50","slug":"prezentacije","status":"publish","type":"page","link":"https:\/\/alice.phy.hr\/index.php\/prezentacije\/","title":{"rendered":"Prezentacije, predavanja, \u010dlanci i sli\u010dno"},"content":{"rendered":"\n
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3.10.2018.<\/p>\n\n\n\n

Grupa je sudjelovala na znanstvenom sastanku Hrvatskog Fizikalnog Dru\u0161tva s posterskim izlaganjem naslova “Primjena tehnika dubokog u\u010denja u fizici te\u0161kih iona”.<\/p>\n\n\n\n

Kako je primarni cilj projekta studiranje dugodose\u017ene “ridge” strukture u dvo\u010desti\u010dnim kutnim korelacijama, glavna prepreka koja ote\u017eava to istra\u017eivanje je visoka pozadina koja poti\u010de od snopova \u010destica u kojima su \u010destice jako korelirane, no nisu dio ridge korelacije. U svrhu razumijevanja i eventualnog uklanjanja te pozadine, usredoto\u010dili smo se na istra\u017eivanje naravi i porijeklo samih snopova. Originalno se to uklanjanje namjeravalo vr\u0161iti kori\u0161tenjem varijable transverzalnog sfericiteta, ali autokorelacije izme\u0111u transversalnog sfericiteta (varijabla koja ovisi o obliku doga\u0111aja) i dvo\u010desti\u010dne kutne korelacijske funkcije (koja tako\u0111er ima ovisnost o obliku doga\u0111aja) donekle onemogu\u0107uju nezavisna mjerenja. Stoga smo paralelno sa sfericitetom krenuli s implementacijom nove obe\u0107avaju\u0107e metode za detekciju i izoliranje tih snopova koriste\u0107i neuralne mre\u017ee i strojno u\u010denje.

Ovdje<\/a> se mo\u017ee vidjeti website sastanka, a klikom na sliku lijevo otvara se link na poster.<\/p>\n\n\n\n

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5.-10.5.2019.<\/p>\n\n\n\n

Na konferenciji “MicroPattern Gaseous Detectors Conference 2019 (La Rochelle, Francuska) odr\u017eali smo predavanje “Correlation of optical and electrical measurements of the delayed discharge propagation in GEM detector” u suradnji s A. Utrobi\u010di\u0107.<\/p>\n\n\n\n

Ovdje<\/a> se mo\u017ee vidjeti website sastanka, a klikom na sliku lijevo otvara se prezentacija.<\/p>\n\n\n\n

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19.07.2019.<\/p>\n\n\n\n

Grupi je u \u010dasopisu Nuclear Instruments and Methods A prihva\u0107en i objavljen \u010dlanak “Studies of the delayed discharge propagation in the Gas Electron Multiplier (GEM)”. <\/p>\n\n\n\n

Preprint \u010dlanka dostupan je na ArXiV<\/a> repozitoriju, dok se sam \u010dlanak mo\u017ee na\u0107i na stranicama \u010dasopisa<\/a>. U radu je opisan na\u010din na koji se izboji propagiraju u GEM detektorima, a izra\u0111en je na laboratorijskom postavu dobivenim HRZZ projektom.<\/p>\n\n\n\n

This paper presents an investigation of the discharge propagation (DP) to the readout electrode that occurs with a microsecond time delay after a primary discharge that develops inside a GEM foil hole. A single hole THGEM (THick GEM) foil that enables a controlled discharge position and the induction of primary discharge with an over-voltage in the THGEM foil has been used in the initial DP measurements. In order to justify the use of a custom-made THGEM foil, additional measurements were made with a standard GEM foil. Correlated optical (with an ordinary SLR and a high-speed camera) and electrical measurements of the delayed DP were made for Ne-CO2-N2 (90-10-5) mixture and with different powering configurations. Measurements show that the delayed DP happens without a drift field, with an inverted induction field, inverted THGEM voltages or an inverted drift field. After the primary discharge, there is a charge transfer in the induction region at an induction field value below that of the onset field for DP. In the time between the primary discharge and the delayed DP, three different current regimes are observed, which suggests multiple charge transfer mechanisms in the induction region. High-speed camera recordings provide valuable insight into the time evolution of the primary and the delayed DP, especially when correlated with electrical measurements.<\/p>\n\n\n\n

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15.08.2019.

Grupi je na konferenciji Quark Matter 2019. (Wuhan, China) prihva\u0107eno postersko izlaganje naslova “Discharge propagation in GEM detectors”. <\/p>\n\n\n\n

Micropattern gaseous detectors (MPGDs) are a group of modern gaseous ionizing detectors consisting of microelectrode structures developed to overcome many of the difficulties of traditional gaseous detectors such as multiwire proportional chambers. The gas electron multiplier (GEM) is one of the most prolific MPGDs currently in use and slated to be used for many future detectors or current detector upgrades. Recent research conducted on discharges in GEM detectors will be presented. Delayed propagating discharges to the readout plane are a potential threat to the stable operation of GEM detectors and can cause permanent damage to the detector. An experimental setup enabling simultaneous electrical and optical measurements is used to provide novel insights regarding the physical mechanism of the delayed discharge, including the microsecond time delay between the primary and secondary discharges. Based on these measurements, indicators of the onset of the delayed propagating discharge are identified by means of the charge transfer to the readout electrode and potential methods to prevent or mitigate the delayed discharge propagation are proposed.
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22.-26.6.2020.

Na konferenciji “RD51 Collaboration meeting and lectures (CERN, online) odr\u017eali smo predavanje “Induction of GEM to GEM discharges by using a single hole THGEM”. Predavanje se mo\u017ee vidjeti ovdje<\/a>.<\/p>\n<\/div><\/div>\n\n\n\n

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7.9.2020.

Grupi je u \u010dasopisu Entropy prihva\u0107en i objavljen \u010dlanak “Exploring the Possibility of a Recovery of Physics Process Properties from a Neural Network Model “. \u010clanak se mo\u017ee na\u0107i besplatno u otvorenom pristupu na stranicama \u010dasopisa.<\/a><\/p>\n<\/div><\/div>\n\n\n\n

The application of machine learning methods to particle physics often does not provide enough understanding of the underlying physics. An interpretable model which provides a way to improve our knowledge of the mechanism governing a physical system directly from the data can be very useful. In this paper, we introduce a simple artificial physical generator based on the Quantum chromodynamical (QCD) fragmentation process. The data simulated from the generator are then passed to a neural network model which we base only on the partial knowledge of the generator. We aimed to see if the interpretation of the generated data can provide the probability distributions of basic processes of such a physical system. This way, some of the information we omitted from the network model on purpose is recovered. We believe this approach can be beneficial in the analysis of real QCD processes.<\/p>\n\n\n\n

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11.2.2021.

Grupi je u \u010dasopisu Nuclear Instruments and Methods A prihva\u0107en i objavljen \u010dlanak “Electrical discharge propagation between GEM foils”. <\/p>\n\n\n\n

\u010clanak mo\u017ee na\u0107i na stranicama \u010dasopisa<\/a>. U radu je opisan mehanizam nastanka proboja u GEM detektorima, a izra\u0111en je na laboratorijskom postavu dobivenim HRZZ projektom.<\/p>\n\n\n\n


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This paper presents the studies of fast sequential discharge formations in neighboring Gas Electron Multiplier foils (so called fast discharge propagations). We report on the characteristics of the time delay between the discharges, which has been shown to be of the order of tens of nanoseconds. This time delay decreases both with increasing voltage on the foil where the secondary discharge occurs as well as with decreasing distance between the neighboring foils. Optical measurements of the discharges in two- and three-stage detector setups show that the propagating discharge does not occur directly below the primary discharge, but is displaced from the shortest line between neighboring foils. This observation, together with Scanning Electron Microscope and Energy Dispersive Spectroscopy analyses of the material deposited below the position of the primary discharge provide valuable information on the time evolution of the fast discharge propagation through the detector and its formation mechanism. In the light of these findings, we propose and discuss a new hypothesis for the occurrence of the secondary discharges.<\/p>\n","protected":false},"excerpt":{"rendered":"

3.10.2018. Grupa je sudjelovala na znanstvenom sastanku Hrvatskog Fizikalnog Dru\u0161tva s posterskim izlaganjem naslova “Primjena tehnika dubokog u\u010denja u fizici te\u0161kih iona”. Kako je primarni cilj projekta studiranje dugodose\u017ene “ridge” strukture u dvo\u010desti\u010dnim kutnim korelacijama, glavna prepreka koja ote\u017eava to istra\u017eivanje je visoka pozadina koja poti\u010de od snopova \u010destica u kojima su \u010destice jako korelirane, … Read morePrezentacije, predavanja, \u010dlanci i sli\u010dno<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/alice.phy.hr\/index.php\/wp-json\/wp\/v2\/pages\/111"}],"collection":[{"href":"https:\/\/alice.phy.hr\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/alice.phy.hr\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/alice.phy.hr\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/alice.phy.hr\/index.php\/wp-json\/wp\/v2\/comments?post=111"}],"version-history":[{"count":36,"href":"https:\/\/alice.phy.hr\/index.php\/wp-json\/wp\/v2\/pages\/111\/revisions"}],"predecessor-version":[{"id":401,"href":"https:\/\/alice.phy.hr\/index.php\/wp-json\/wp\/v2\/pages\/111\/revisions\/401"}],"wp:attachment":[{"href":"https:\/\/alice.phy.hr\/index.php\/wp-json\/wp\/v2\/media?parent=111"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}