Homogenost temperature v kriostatu

PUNGERČAR MARN, ŽIGA (author), Bojkovski, Jovan (mentor)

Povzetek V diplomski nalogi smo opravljali prostorske in časovne meritve homogenosti temperature v kriostatu K22. Cilj naloge je ugotoviti homogenost temperature v njem in ugotoviti, kateri dejavniki oziroma v kolikšni meri ti vplivajo na same rezultate. Meritve smo opravljali v temperaturnem območju od -190 °C do +2 °C, območje nastavljene temperature pa smo določili naknadno. Meritve smo opravljali s tremi termometri. Z referenčnim termometrom smo vedno merili maksimalno možno potopitev termometra v kriostatu, druga dva termometera pa smo postopno dvigovali. Prva meritev je bila izvedena, ko sta bila oba termometra potopljena na dno kriostata. Meritve smo v intervalih opravljali, dokler nismo dobili rezultata oziroma meritve, ki je zaradi zunanjih vplivov preveč odstopala od referenčne temperature. Pričakovali smo, da se bodo meritve zaradi vpliva zunanjih dejavnikov (predvsem sobne temperature) precej razlikovale od referenčne temperature. Termometra smo na koncu med seboj zamenjali, saj smo s tem dokazali, da je razlika med njima posledica negotovosti ali pa dejanska razlika med termometroma. Nato smo postopek ponovili na novi temperaturni vrednosti. Zaželjeno je, da bi merjenja opravljali predvsem na najnižji in najvišji možni temperaturi. Zavedamo se, da na meritve vpliva tudi zgradba termometra. Tu so pomembnejšo vlogo predstavljali predvsem material, oblika in premer. Za zajem in shranjevanje podatkov nam je bila v pomoč programska oprema LabVIEW. Meritve homogenosti temperature smo opravili na najbolj oddaljenih vhodih ter na centralnem referenčnem vhodu. Razlog je predvsem ta, da smo pričakovali, da bomo tako merili v najslabšem možnem položaju in tako izničili možnost, da meritve niso zadovoljive. V vsakem primeru, tudi če meritve opravljamo z večimi termometri, je zaželjeno, da je referenčni termometer postavljen v referenčni vhod.

• Language: Slovenian
• Keywords: temperatura, kriostat, meritve, stabilnost, homogenost, tekoči dušik.
• Work type: Bachelor thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2015
• PID: 20.500.12556/RUL-73383
• Publication date in RUL: 06.11.2015

Secondary language

• Language: English
• Title: Temperature homogeneity of croystat

Abstract

Abstract In the following thesis, space and time measurements of temperature homogeneity of cryostat K22 is discussed. The goal was to determine the extent of the temperature homogeneity as well as the factors affecting it. Measurements in a temperature range from -190 °C to +2 °C were performed, with specific temperature area determined subsequently. The measurements were taken with three thermometers. With the reference thermometer maximum immersion at the bottom of cryostat was measured, while the other two thermometers were gradually raised. The first measurement was performed when the two thermometers were immersed to the bottom of the cryostat. The measurements were taken in intervals until we reached the result whereby due to external influences the measurement substantially deviated from the reference temperature. In the final stage, we replaced both thermometers in order to minimize the inconsistencies of both measuring devices. Then we repeated the process at a new temperature value. It was desired that the measurements were performed at the lowest and highest possible temperature. We took into account that the structure of the thermometers also affected the measurements. The most important influence represented the material, their shape and diameter. To capture and store data we used software LabVIEW. Measurements of temperature homogeneity were performed at the outermost entrances and at the central reference input. The main reason was that we intended to take measurements at the worst possible position and thus prove that the method used was objective.

• Keywords: temperature, cryostat, measurements, stability, homogeneity, liquid nitrogen.