Photon beam
The Photon beam was a laser weapon incorporated by Professor Marius into his invention, K9.
Characteristics
In standard K9 models, a metal tube came out of a hole at the front of the robot's head and it fired the beam. However, in the case of K9 Mark I's future incarnations such as K9 Mark 2, it was simply fired out of the hole, several smaller holes inside also lit up when the weapon was charged. (K9TV: Mind Snap) For Mark II and early instances of Mark III, the beam was red. (DW: The Invasion of Time, The Ribos Operation, KAC: A Girl's Best Friend) Although in K9 Mark I and III's later life along with K9 Mark IV[statement unclear] and K9 Mark I's later incarnations, the beam was a more orange colour. (DW: School Reunion, SJA: The Gift, K9TV: Liberation)
Settings
The original K9 Mark I, along with his future incarnation's photon beam was able to both stun and kill. However later models created by the Fourth Doctor could only stun.
Abilities and Weaknesses
Note that abilites demonstrated in more advanced models may not be present in earlier versions, as such, the specific model is stated.
K9 Mark I's photon beam was ineffective against Sontaran armour. (DW: The Invasion of Time) K9 Mark II's photon beam was able to destroy Daleks. (DWM: The Dogs of Doom) K9 Mark IV's photon beam could disintergrate a swarm of Rakweed spores. (SJA: The Gift)
K9 Mark 2's photon beam was able to heat and cook food, such as a tin of baked beans, although it resulted in the beans bursting out of the tin. When K9 applied this technique to a Korven, it killed it in an unusual manner, white light seem to emerge from it's eyes and mouth and it's body cracked with white light before finally exploding, leaving it's clothes and held objects behind. (K9TV: The Korven) It could deactivate a device such as a Space-Time Manipulator without damaging it. (K9TV: Oroborus) It could also be turned into a photon spread which could hold off gas from a vapour bomb. (K9TV: The Last Oak Tree)
The Jixen were able to reflect and enhance photon beams, meaning that K9 was merely able to halt them with a shot. This ability was later incorperated into Trojan, in this case, Trojan was so strong it was able to knock K9 back. (K9TV: The Eclipse of the Korven)
