Move Particles

I cant figure out how to make my particles move with velocity.

tried a few things but none worked. and i dont understand the function get particles.

thank you for your time

 using UnityEngine;
 using System.Collections;
 
 public class SunPhotons : MonoBehaviour {
     
     
     public int InitSpeed=75;
 
         int j=0;    
 
     public int NumberOfParticles=100;
     
     private ParticleSystem.Particle[] Photons;
         private ParticleSystem.Particle[] Photons2;
 
     bool isInitializedPosition=false;
     Vector3 LocationForDebug = new Vector3(0,0,0);
     Vector3 SpeedForDebug = new Vector3 (10,10,10);
     
     void Start () {
         
           
         Photons = new ParticleSystem.Particle[NumberOfParticles];
     
     }
     
     
         
 
         
         
     
     
     // Update is called once per frame
     void LateUpdate () {
     int i;
         ParticleSystem SunRay = GameObject.Find("SunRay").GetComponent<ParticleSystem>();
     for ( i = 0; i < NumberOfParticles; i++)
         {
             if (!isInitializedPosition)
             {
                 Photons[i].position=LocationForDebug;
                 Photons[i].color=new Color(10,0,0);
                 Photons[i].startLifetime=2;
                 Photons[i].lifetime=4;
                 Photons[i].size=0.2f;
                 
             }
             Photons[i].velocity=SpeedForDebug;
             Photons[i].angularVelocity=0.4f;
             
             
     //        Photons[i].position= new Vector3((i+j)/100f,0,0);
             particleSystem.SetParticles(Photons,NumberOfParticles);
             
         }
         particleSystem.SetParticles(Photons,NumberOfParticles);
         j++;
         
         GameObject.Find("SunRay").GetComponent<ParticleSystem>().GetParticles(Photons2);
         isInitializedPosition=true;
     }
 }