Editing Proton pack (section)

==In the ''Ghostbusters'' universe==
[[File:Ghost trap.png|thumb|upright|left|A replica of the ghost trap used in the original film]]
The proton pack, designed and built by [[Egon Spengler|Dr. Egon Spengler]], is a man-portable [[cyclotron]] system (and indeed Dr. [[Peter Venkman]] refers to the proton packs in one scene as "unlicensed nuclear accelerators"),<ref name="Ghostbusters" /> that is used to create a [[charged particle beam]]—composed of protons—that is fired by the particle thrower (also referred to as the "neutrona wand"). Described in the first movie as a "[[electron-positron collider|positron collider]]", it functions by colliding high-energy positrons to generate its proton beam. The beam allows a Ghostbuster to contain and hold "negatively charged [[ectoplasm (paranormal)|ectoplasm]]ic entities". This containment ability allows the wielder to position a ghost above a trap for capture.<ref name="Ghostbusters">{{cite video |people= [[Ivan Reitman|Reitman, Ivan]] (Director), [[Dan Aykroyd|Aykroyd, Dan]] and [[Harold Ramis|Ramis, Harold]] (Writers) |date= 1984-07-08| title= Ghostbusters |url= https://www.imdb.com/title/tt0087332/ |medium= Motion picture |access-date= 2009-09-13}}</ref> The stream is also quite destructive to physical objects, and can cause extensive property damage.<ref name="Ghostbusters" />

The name ''proton pack'' is not used in the [[Ghostbusters|original movie]] at all,{{sfn|Bergman, Lambert|2011|p=229|ref=geektionary}} and is not used until the subway tunnel scene in ''[[Ghostbusters II]]'', when Egon says that they should get their proton packs. The doorman to the Mayor's mansion also uses the term ''proton pack'', asking the Ghostbusters if he can buy one from them for his little brother. Egon replies that "A proton pack is not a toy".

In the 1984 novelization of ''Ghostbusters'', the Proton Packs are mentioned, eg. “Stantz hauls out the formidable weaponry from the back of the Ectomobile and the four men kit themselves up, buckling on their proton packs…”<ref>"Ghostbusters - A novel based on the screenplay by Dan Aykroyd and Harold Ramis" by Larry Milne. Cornet 1984. {{ISBN|0-340-37251-6}}</ref>

In the [[Ghostbusters: The Video Game|2009 ''Ghostbusters'' game]], Ray explains how the proton pack works early in the game; the energy emitted by the proton stream helps to dissipate [[psychokinesis|psychokinetic]] (PK) energy which ghosts use to manifest themselves. Draining them of their PK energy weakens them, allowing them to be captured in their portable ghost traps.

According to a line spoken by Egon in ''Ghostbusters II'', each pack's energy cell has a [[half-life]] of 5,000 years.<ref name="Ghostbusters2">{{cite video |people= [[Ivan Reitman|Reitman, Ivan]] (Director), [[Dan Aykroyd|Aykroyd, Dan]] and [[Harold Ramis|Ramis, Harold]] (Writers) |date= 1989-07-16| title= Ghostbusters II |url= https://www.imdb.com/title/tt0097428/ |medium= Motion picture |access-date= 2009-09-13}}</ref> Knobs on the main stock of the proton pack can perform various functions to customize the proton stream, including adjustments for stream intensity, length, and degrees of [[Polarization (waves)|polarization]].{{citation needed|date=September 2009}} In the cartoon series ''[[The Real Ghostbusters]]'', the maximum power setting for the proton packs is "500,000 MHz," which possibly refers to the rate of positron collisions occurring within the pack's accelerator system. In the cartoon the packs also have a self-destruct mechanism capable of affecting at least a half-mile radius. ''The Real Ghostbusters'' also made proton packs less efficient with power cells, allowing them to run out of energy when appropriate for dramatic tension.<ref name="RealBusters">{{cite video |date= 1986| title= The Real Ghostbusters |url= https://www.imdb.com/title/tt0090506/ |medium= Television show |access-date= 2009-09-13}}</ref>

For the 1997 animated spinoff ''[[Extreme Ghostbusters]]'', the proton packs and ghost traps are redesigned to combat the threat of the malevolent Achira, an ancient disease-provoking entity accidentally released by workers constructing a new subway tunnel. Egon, with the help of Roland, Kylie and Eduardo, increased the proton packs' nuclear capability (to deal with Achira and other subsequent enemies, much stronger than what the original Ghostbusters had faced) and modified the power system; now, the packs required replaceable proton canisters to be loaded in for them to function. The trap was redesigned as well, into a gold-colored, round-shaped device with an opening hatch atop it. Kylie would typically carry it; due to this, she did not carry a normal proton pack, instead carrying a not-as-powerful proton pistol.

The [[IDW Publishing|IDW]] monthly ''Ghostbusters'' comic storyline has shown the movie pack, a boson dart capable pack and the Extreme Ghostbusters pack in use. The IDW comic also shows a proton pistol attachment to the movie pack being used by Winston while hunting down Slimer.

===Crossing the streams===
{{blockquote|There's something very important I forgot to tell you! Don't cross the streams… It would be bad… Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light.|Dr. Egon Spengler (Harold Ramis) on crossing proton streams}}

Crossing the streams was initially discouraged, as Egon believed that "total protonic reversal" would occur: this effect would have catastrophic results (see quote above) if they are crossed over three seconds. However, in a desperate effort to stop the powerful [[Ghostbusters (franchise)#Gozer|Gozer the Gozerian]], Egon noted that the door to Gozer's temple "swings both ways" and that by crossing the streams, they may be able to create enough force to close the door on Gozer and its control. As the Ghostbusters cross the streams, the combination of that much energy closes the door to Gozer's dimension and severs its ties to our world. The resulting blast destroys a good portion of the roof and blows up the [[Stay Puft Marshmallow Man]].<ref name="Ghostbusters" />

In ''[[Ghostbusters: The Video Game]]'', the Ghostbusters mention that "crossing the streams" during the Gozer Incident (events of the first ''Ghostbusters'' film) only worked due to the presence of a cross-dimension portal (a tactic which is referred to as the "Gozer gambit" by Ray) and should only be used as a last resort. During the game's climax, the Ghostbusters are pulled into Ivo Shandor's ghostly realm and come face-to-face with Shandor's Destructor form, forcing them to resort to "crossing the streams" to defeat Shandor. The resulting blast not only destroys Shandor but also sends the team flying back to their dimension. During gameplay, it is possible for the player to cross the streams with another Ghostbuster, but this will only cause a burst of energy to travel down the stream and deal a massive amount of damage to the player, while also knocking them off their feet for a short time, due to a new "safety" that was installed on the neutrona wand.

In the extended version of the reboot film ''[[Ghostbusters (2016 film)|Ghostbusters]]'' (2016), shows that its iteration of the Ghostbusters (Abby Yates, Erin Gilbert, Jillian Holtzman, and Patty Tolan) had initially tried to close Rowan North's portal with their crossed streams before resorting to use their Ecto-1's reactor to detonate an explosion to create the total protonic reversal powerful enough to seal it.

In ''[[Ghostbusters: Afterlife]]'', Egon built proton cannons with the parts of the proton packs and a PKE meter in Summerville, [[Oklahoma]], to keep Gozer's portal closed with safely fired crossed streams. Later, the Ghostbusters again crossing their proton streams against Gozer to counter its energy-based powers and to weaken its physical form, allowing them to capture the deity in their 198 ghost traps.