From 933462c52b309ab576d478588e7c90d5f56c1295 Mon Sep 17 00:00:00 2001 From: Eugeniy Mikhailov Date: Sat, 25 Oct 2014 11:37:27 -0400 Subject: typos fixed thanks to Calvin --- supcon.tex | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) (limited to 'supcon.tex') diff --git a/supcon.tex b/supcon.tex index 3a5d408..0e13d84 100644 --- a/supcon.tex +++ b/supcon.tex @@ -75,7 +75,7 @@ place items in the liquid nitrogen. \section*{Experimental procedure} -\textbf{Equipment needed}: YBCO disc, tweezers, styrofoam dish, small magnet. +\textbf{Equipment needed}: YBCO disk, tweezers, thermal insulating container, small magnet. @@ -84,17 +84,18 @@ place items in the liquid nitrogen. \begin{enumerate} \item Place one of the small magnets (provided) on top of the superconducting -disc at room temperature. Record the behavior of the magnet. +disk at room temperature. Record the behavior of the magnet. -\item Using the tweezers, place the superconducting disk in the styrofoam - dish. Attach the thermocouple leads (see diagram) to a multimeter +\item Using the tweezers, place the superconducting disk in the thermal + insulating container. + Attach the thermocouple leads (see diagram) to a multimeter reading on the mV scale. Slowly pour liquid nitrogen over the disk, - filling the dish as much as you can. The nitrogen will boil, and + filling the container as much as you can. The nitrogen will boil, and then settle down. When the multimeter reads about 6.4 mV, you are at liquid nitrogen temperature (77 K). -\item After the disc is completely covered by the liquid nitrogen, use the tweezers +\item After the disk is completely covered by the liquid nitrogen, use the tweezers to pick up the provided magnet and attempt to balance it on top of the superconductor disk. Record what you observe. @@ -110,7 +111,7 @@ moving the magnet across the superconductor. Do you feel any resistance? If you critical temperature. Make sure you record it! \item Repeat the experiment by starting with the magnet on top of the -superconductor disc and observe if the magnet starts levitating when the disk's +superconductor disk and observe if the magnet starts levitating when the disk's temperature falls below critical. \end{enumerate} @@ -138,10 +139,10 @@ At room temperature, you should be reading a non-zero \begin{enumerate} \item With the voltage, current and thermocouple leads attached, - carefully place disk in dish. Pour liquid nitrogen into the - dish. Wait until temperature reaches 77 K. -\item With tweezers, take disk out of nitrogen and place on a side of the - dish. {\bf Start quickly recording the current, voltage and thermocouple readings + carefully place the disk in the container. Pour liquid nitrogen into the + container. Wait until temperature reaches 77 K. +\item With tweezers, take the disk out of nitrogen and place it outside of + the container. {\bf Start quickly recording the current, voltage and thermocouple readings as the disk warms up.} When superconducting, the disk should have V=0 (R=0). At a critical temperature, you will see a voltage (resistance) appear. -- cgit v1.2.3