Edit in JSFiddle

var game = new Phaser.Game(800,600,Phaser.CANVAS,"particulas",{preload: preload, create: create, update: update});

var emitter;

function preload(){
    game.load.spritesheet("pelota","data:image/png;base64,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",16,16);
}

function create(){
    emitter = game.add.emitter(64,64,400);
    emitter.makeParticles("pelota",0,400,true,true);
    emitter.setXSpeed(-64,64);
    emitter.setYSpeed(-10,10);
    emitter.gravity = 1000;
    emitter.bounce.setTo(1,0.7);

    emitter.start(false,0,10);
}
function update(){
    game.physics.arcade.collide(emitter);
}