def ltcube(self, **kwargs):
        """ return the name of a livetime cube file
        """
        kwargs_copy = self.base_dict.copy()
        kwargs_copy.update(**kwargs)
        kwargs_copy['dataset'] = kwargs.get('dataset', self.dataset(**kwargs))
        localpath = NameFactory.ltcube_format.format(**kwargs_copy)
        if kwargs.get('fullpath', False):
            return self.fullpath(localpath=localpath)
        return localpath