Spiral points at fixed distance and random angle

With this code I get 3 spirals but the 2dn and 3rd spiral their points are at further distances.

I want something where I can control the number of spirals and then equally devide them.
The first image shows the result with this code,
the second image is the desired result:

var pointObject			: GameObject;
var spiralNumber		: int = 1;
var pointDistance		: float = 0.1;
var spiralLength 		: float = 30;

function Start()
	for (var arm : int = 0; arm < spiralNumber; arm++)
		pointDistance = 0.1 + (arm/2);
		for(var point :int = 0; point < spiralLength; point++) 
			var randomPos :Vector2; 
		   	randomPos.x = point * pointDistance * Mathf.Cos(pointDistance);
		 	randomPos.y = point * pointDistance * Mathf.Sin(pointDistance);
	        Instantiate(pointObject, Vector3(randomPos.x, 0, randomPos.y), Quaternion.identity);
			pointDistance += 0.1;

I don’t know what you mean by random angle. There are a lot of both parametric and polar equations out on the net for different kinds of spirals if all you are going for is
different look. If evenly spaced points is your goal, one spiral-like form that meets that criteria is the Spiral of Theodorus.