Buborékkamra

A Peter Sonnek (University of Mississippi) által készített Java szimuláció csak letöltve futtatható. A zippelt könyvtárat a következő helyről szedhetjük le:

http://www.phy.olemiss.edu/HEP/QuarkNet/bubble3.html.

Ha a hely nem érhető el, akkor innen is letölthetjük. Kicsomagolás után két kattintás a Bubble.jar nevű fájlra, és elindul a látványos szimuláció.

Néhány instrukció, ill. megjegyzés a szerzőtől, melyet a levelezésünkből vágtam ki. És itt egy régi használati utasítás, melyet szintén elküldött: .

• The program is a stand alone java program and not an applet, so it will have to be started using the java run time environment. The command that needs to be executed is "java -jar Bubble.jar", but this cannot be done straight from power point since you need to "cd" into the proper directory. If you are running windows, I attached a batch (.bat) file which can be linked from power point as a hyper link. You will need to edit this file with a text editor to adapt the directory to the directory where you have chosen to store the bubble program "c:\....\Bubble1.1". It needs to point from "c:\..."
  onwards. Put the ".bat" file into the same directory which holds the Bubble.jar file. Then make a hyperlink in Power Point pointing to "bubble.bat". If you click on the hyperlink in power point it will probably ask you twice if you trust the execution. After that the program starts with power point still in the background. If you are running Linux or Mac OS you should be able to do the same with a "bash" script. The syntax is the same. I am sure there are many other workarounds, but this is the quickest I came up with. Let me know if this doesn't work for you and I will think of something else. Please feel free to contact me if you have any questions. I am glad my program is seeing some use.
  P.S.: Just in case the spam filter deletes the attachment (ez bekövetkezett) here is the syntax of the batch file "bubble.bat". It can be created with a simple text editor:
  cd "c:\Documents and Settings\peter\Desktop\Bubble1.1"
  java -jar Bubble.jar
  
• Yes, I don't know of a way to embed the program into power point. You would have to copy the program with your power point slide onto your memory stick and then copy it to the other computer. As long as it will have the java runtime environment installed (which it should) the program will run. You will have to adapt the batch script though. I am not sure if Vista still supports batch scripts, but I hope it does.
  As to your question, the sign of the particles should be different depending on the direction of "curl" as you have mentioned. I checked the program quickly and in the bubble chamber portion of the program the identify track part works fine (you get there by choosing File->Event Type and then choosing K- + pi+ -> pi+ + lambda + pi-). This was the mode the program originally started in and it simulates the collision of a Kaon with a proton producing a pi+, pi- and a lambda. The lambda remains undetected in the chamber and pi+ then decays further into a proton and another pion. This is based on the historic discovery of the lambda particle. The Identify Track option works properly there. If you are in the "Higgs" mode, there is a small bug in the program.
  The grayed tracks are supposed to represent background in the event and since they all have the same color the identify track method doesn't work there. It is supposed to identify only the colored tracks. I will try to fix that.
  
• The magnetic field is perpendicular to the screen. It by default points into the screen and is homogeneous. Its strength and direction can be adjusted in the File->Event Type->Chamber Settings tab.
  The picture you see at the beginning is a cross section view of the CMS detector at CERN which is a cylinder. The magnet is a coil and therefore produces a somewhat homogeneous field in its center with a strength of 4 tesla. Technically this field weakens the closer one gets to the coil and reverses outside the coil. My program just assumes a 4 T homogeneous field everywhere. This isn't exactly true but the difference is not that significant for this simple conceptual simulation. The reason being is that this program was originally a bubble chamber simulation only and I added the CMS part on top of that for a workshop we had here at the University. So it is not an accurate simulation, but it gets the point across. For the CMS part the program tries to simulate energy depositions in the calorimeters which can be analyzed and used to "discover" the Higgs particle. We had a few high school classes here at the University last Summer (or the one before) which used this to understand the basics on how high energy physics analyses are done. You can get to this feature by clicking on "Find Particle From Decay" and it will open an unrolled version of the two calorimeters. Unfortunately this feature is not very self explanatory and hard to understand without a manual (which I haven't written yet for this part). Here is a link that describes the detector a little bit (http://cms.web.cern.ch/cms/Detector/FullDetector/index.html) and here are some pictures of it (http://cms.web.cern.ch/cms/Media/Images/PhotoBook/index.html).