private void createShockwave(){
                AssetManager assetManager = getApplication().getAssetManager();
                shockwave = new ParticleEmitter("Shockwave", ParticleMesh.Type.Triangle, 1);
//        shockwave.setRandomAngle(true);
                shockwave.setFaceNormal(Vector3f.UNIT_Y);
                shockwave.setStartColor(new ColorRGBA(.48f, 0.17f, 0.01f, .8f));
                shockwave.setEndColor(new ColorRGBA(.48f, 0.17f, 0.01f, 0f));

                shockwave.setStartSize(0f);
                shockwave.setEndSize(7f);

                shockwave.setParticlesPerSec(0);
                shockwave.setGravity(0, 0, 0);
                shockwave.setLowLife(0.5f);
                shockwave.setHighLife(0.5f);
                shockwave.getParticleInfluencer()
                        .setInitialVelocity(new Vector3f(0, 0, 0));
                shockwave.getParticleInfluencer().setVelocityVariation(0f);
                shockwave.setImagesX(1);
                shockwave.setImagesY(1);
                Material mat = new Material(assetManager, "Common/MatDefs/Misc/Particle.j3md");
                mat.setTexture("Texture", assetManager.loadTexture("Effects/Explosion/shockwave.png"));
                shockwave.setMaterial(mat);
                explosionEffect.attachChild(shockwave);
            }
This test's particle effects (using an explosion)
jme3-screenshot-tests/src/test/java/org/jmonkeyengine/screenshottests/effects/TestExplosionEffect.java