Here's my version of the ML-16. It still need some tweaking, but you can get a feel for it. The Prometheus will be similiar (green, different damage, probably more energy consumption to balance things).
NOTE: I'm using fs2_open3.5.5
$Name: @ML-16 Laser
+Title: XSTR("GTW ML-16 Laser", 3246)
+Description:
XSTR(
"Standard issue
Level 3 Hull Damage
Minimal Shield Damage", 3247)
$end_multi_text
+Tech Title: XSTR("ML-16 Laser", 3248)
+Tech Anim: cb_ml16
+Tech Description:
XSTR(
"Argon laser weapon - uses transparent ceramic technology in order to create an optical system that is extremely durable and stable under battle conditions - provides adequate destructive damage to the hull of enemy ships by vaporizing molecular bonds at the target area and destabilizing molecular bonds across the grain of the hull material. The GTA issues ML-16 Lasers to every fighter and bomber in service.", 3249)
$end_multi_text
$Model File: none
@Laser Bitmap: laserglow06
@Laser Glow: 2_laserglow03
@Laser Color: 190, 150, 250
@Laser Color2: 190, 150, 250
@Laser Length: 7.0
@Laser Head Radius: 0.90
@Laser Tail Radius: 0.30
$Mass: 0.0
$Velocity: 450.0
$Fire Wait: 0.2
$Damage: 0.5
$Armor Factor: 0.1
$Shield Factor: 0.01
$Subsystem Factor: 0.3
$Lifetime: 2.0
$Energy Consumed: 10.0
$Cargo Size: 0.0
$Homing: NO
$LaunchSnd: 115
$ImpactSnd: 85
+Weapon Range: 100000
$Flags: ("player allowed" "beam" "no Pierce shields")
$Icon: icon_ml16
$Anim: ml16
$Impact Explosion: none
$BeamInfo:
+Type: 2
+Life: 0.0
+Warmup: 0
+Warmdown: 0
+Radius: 1.0
+PCount: 0
+PRadius: 0
+PAngle: 0.0
+PAni: particleexp01
+Miss Factor: 0.0 0.0 0.0 0.0 0.0
+BeamSound: 115
+WarmupSound: 0
+WarmdownSound: 0
+Muzzleglow: beamglow5
+Shots: 0
+ShrinkFactor: 0.0
+ShrinkPct: 0.0
+Range: 900 ; Maximum range of a beam
+Attenuation: 0.5 ;From 0.0 to 1.0 indicates the point at wich the beam's damage will start to degrade
$Section:
+Width: 0.5
+Texture: beam-white
+RGBA Inner: 255 255 255 255
+RGBA Outer: 150 150 150 10
+Flicker: 1.0
+Zadd: 2.0
$Section:
+Width: 0.75
+Texture: beam-purple2
+RGBA Inner: 160 160 0 255
+RGBA Outer: 60 60 0 10
+Flicker: 1.0
+Zadd: 1.0
$Section:
+Width: 1.0
+Texture: beam-purple
+RGBA Inner: 255 0 0 255
+RGBA Outer: 60 0 0 10
+Flicker: 1.0
+Zadd: 0.0