An officer then allegedly pulled a sealed emergency release button that shut the MRI machine down, deactivating it, evaporating thousands of liters of helium gas and damaging the machine in the process. The officer then grabbed his rifle and left the room, leaving behind a magazine filled with bullets on the office floor, according to the lawsuit.
The shutdown did have to happen (because the cop is a dumbass) but it obviously should have been done by someone who knows what they are doing. The guy should be suspended for being a dumbass and also for leaving his loaded magazine.
To give some background on this, the huge magnetic field in an MRI machine is created by a superconducting magnet. A magnetic coil submerged in liquid helium that keeps it ultra cold has virtually no resistance, so the electricity can keep going round and round and round like a racetrack without being bled off by resistance. This lets the machine maintain a very high magnetic field with very little power input.
An MRI technician can gradually ramp up or down the magnetic field power by slowly adding or removing current from the magnet. To retrieve the officer’s rifle, they could have slowly ramped down the power with a magnetic power supply while the magnet stayed cold.
When the guy slams the emergency button that does what’s called a quench. It adds resistance to the magnet, which starts turning that power into heat, and that heat boils off all the liquid helium and rapidly ramps the magnet down to zero. This should only be done if for example a patient is trapped in the machine by a metal object or similar emergency, because it damages the magnetic coil and also boils away the liquid helium, which itself is worth thousands of dollars.
LAPD (or more specifically, the California taxpayers) are in for a pricey repair bill.
The mechanism they are describing here is the emergency one (like if a human is trapped against the machine by something metal and is being crushed - you need to kill the magnet NOW). There is a slower, much safer mechanism for deactivating the magnet that should have been used here but that would require the officer admitting he had made a mistake and asking for help.
Also I just want to point out that the rifle should be considered no longer safe to use unless thoroughly inspected by an expert. In a similar case some years back, the police officer’s sidearm was pulled into the machine. After retrieval it was found that the weapon had been magnetized by the scanner and as a result the firing pin was able to spontaneously release.
The shutdown did have to happen (because the cop is a dumbass) but it obviously should have been done by someone who knows what they are doing. The guy should be suspended for being a dumbass and also for leaving his loaded magazine.
To give some background on this, the huge magnetic field in an MRI machine is created by a superconducting magnet. A magnetic coil submerged in liquid helium that keeps it ultra cold has virtually no resistance, so the electricity can keep going round and round and round like a racetrack without being bled off by resistance. This lets the machine maintain a very high magnetic field with very little power input.
An MRI technician can gradually ramp up or down the magnetic field power by slowly adding or removing current from the magnet. To retrieve the officer’s rifle, they could have slowly ramped down the power with a magnetic power supply while the magnet stayed cold.
When the guy slams the emergency button that does what’s called a quench. It adds resistance to the magnet, which starts turning that power into heat, and that heat boils off all the liquid helium and rapidly ramps the magnet down to zero. This should only be done if for example a patient is trapped in the machine by a metal object or similar emergency, because it damages the magnetic coil and also boils away the liquid helium, which itself is worth thousands of dollars.
LAPD (or more specifically, the California taxpayers) are in for a pricey repair bill.
He probably shit his pants at the deafening sound of an MRI machine being quenched, and had to leave quickly to change them.
The mechanism they are describing here is the emergency one (like if a human is trapped against the machine by something metal and is being crushed - you need to kill the magnet NOW). There is a slower, much safer mechanism for deactivating the magnet that should have been used here but that would require the officer admitting he had made a mistake and asking for help.
Also I just want to point out that the rifle should be considered no longer safe to use unless thoroughly inspected by an expert. In a similar case some years back, the police officer’s sidearm was pulled into the machine. After retrieval it was found that the weapon had been magnetized by the scanner and as a result the firing pin was able to spontaneously release.
Just hit it against a table a bunch while shouting “stop being a magnet”.