(a) Violations of chapter or regulations Any person who willfully and knowingly violates this chapter or any regulation under this chapter shall be fined not more than $1,000 or sentenced to prison for a term not to exceed one year, or both. Upon conviction for any subsequent violation of this chapter or any regulation under this chapter, the defendant shall be fined not more than $10,000 or sentenced to prison for a term not to exceed three years, or both. (b) Violations of section 1324a(a) of title