Using a open source software called "Art of Illusion", a simple sketch of the fermi PMT is drawn for a better view.

Install the software
1. go to http://www.artofillusion.org/downloads or use the attached setup file (for linux platform)
2. unzip the file, and run the aoisetup.sh script to start installation.
3. after the installation, run the script /file/aoi.sh to start the program.

Look at the 3-D PMT file
1. simply, download the attached design1.zip on this page and unzip it, there should be a tube.aoi file in it.
2. open this tube.aoi file from the Art of Illusion software. You should see four different windows of different views. Maybe you will need to zoom out on the left two windows since I use larger scale ( unit of centimeter).
3. on the left there are a few buttons, , the bottom two with brown eye icon can allow us to freely move and rotate the general view of the design without moving certain parts in case the position is messed up.
4. you can also select the certain part from the objects window, then enter the different x-position of the properties window below to see how the shield and caps can be slide in. Also all other parameters (y-z position and orientation) are already properly aligned.
5. if you want to rotate certain parts, select that part and then go to left and press the green ball icon for free translation and rotation. Or, right click from the Objects windown and press copy and paste it to a new file or other place for a better viewing.
6. more documentation and tutorials are on http://www.artofillusion.org/documentation.

this is how the program looks: