In Junos OS, there is no supported operational command that you can use to shut down an interface. However, you can disable the interface by adding the following disable command to the interface configuration and committing the change:
set interfaces ge-0/0/0 disable
Alternatively, use ifconfig from the shell prompt at your own risk:
ifconfig ge-0/0/0 down
How would I check in the shell prompt if an interface has been set to down (vial shell)?