Physics behind Predator's Shoulder Cannon

[infinitebubble]

Avid fan of the Predator series of movies and the technology of the weapons of choice for the predator characters. Of interest is the shoulder mounted cannon that fires plasma bolts directed by their laser tracking device. All this technology is either in use today or in the lab/miniaturization stages.

Any discussions about the technology and why we could not create this today?

 

[jedishrfu]

Its probably weight. In the wiki article it says 20kg for a device that has the power of an airgun.

https://en.wikipedia.org/wiki/Plasma-powered_cannon

 

[Ryan_m_b]

I assume you're asking about why weapons aren't shoulder mounted and automated, as opposed to the SciFi concept of a plasma gun? Mounted weapons that follow the operator's vision exist already, albeit not at an infantry level:
https://en.wikipedia.org/wiki/Boeing_AH-64_Apache#Avionics_and_targeting

Reasons why such a system hasn't been developed probably include a low return on investment. I'm not sure the advantage would be that much greater than regular training in marksmanship. In addition disadvantages would include the huge cost, extra complexity (and therefore potential failure modes) and reduction in mobility from having some sort of heavy backpack (with batteries, computer, auto-loader etc) and waldo arm.

 

[Bandersnatch]

https://en.wikipedia.org/wiki/Plasma-powered_cannon

This is not similar to what the OP is talking about. This weapon is plasma-powered, i.e. it uses plasma to propel regular projectiles. The SF version fires 'plasma bolts'.
The closest to a real world example I could find after admittedly cursory googling is this project:
https://inis.iaea.org/search/searchsinglerecord.aspx?recordsFor=SingleRecord&RN=22057516
https://www.osti.gov/scitech/biblio/7369133#
Which as far as I can see accelerated compact plasma projectiles. But resources on the state of the project are limited (and inundated in conspiratorial fluff). Calling it an existing technology is probably not justified.
Furthermore, there's always the issue of maintaining cohesion of the plasma outside the confining environment. What good is accelerating some plasma if it'll dissipate moments after exiting your gun?

But then again, I know next to nothing about plasma physics. Maybe dissipation time frame can be long enough for a sufficiently fast moving projectile to deliver some energy to a reasonably distant target? Maybe it can't work at all outside vacuum? Maybe it's all as good as bunkum.

and waldo arm

Perhaps if it was mounted on a reciprocating dingle arm instead...

 

[infinitebubble]

Excellent replies... I was looking more at these type of technology only created such to be wearable's much like the Predators plasma cannon. Sure the largest drawback will be the power density to create the Joules needed to make the plasma viable to reach it's target. Understand the plasma pulse will dissipate quite rapidly but this is the premise... how do we make this plasma last till it hits the target? I'm thinking having the plasma field surrounding a 'liquid metallic projectile' which would be shot at electromagnetic velocities? See what the military DARPA unit is creating below:

http://www.military.com/video/off-duty/tech/new-progress-on-plasma-weapons/2324951333001