EXHIBIT 5.1


                                September 6, 2002



Vicor Corporation
25 Frontage Road
Andover, Massachusetts  01810

      Re:      Vicor Corporation/Registration Statement On Form S-8
               ----------------------------------------------------

Ladies and Gentlemen:

      This opinion is furnished in connection with the registration pursuant to
the Securities Act of 1933, as amended (the "Act"), of 2,000,000 additional
shares (the "Shares") of common stock, par value $.01 per share (the "Common
Stock"), of Vicor Corporation (the "Company") which may be issued pursuant to
the Company's Amended and Restated 2000 Stock Option and Incentive Plan (the
"Plan").

      We have acted as counsel to the Company in connection with the
registration of the sale of the Shares under the Act. We have examined the Plan,
the Restated Certificate of Incorporation and the Amended and Restated By-laws
of the Company; such records of the corporate proceedings of the Company as we
deemed material; and such other certificates, receipts, records and documents as
we considered necessary for the purposes of this opinion.

      We are attorneys admitted to practice in the Commonwealth of
Massachusetts. We express no opinion concerning the laws of any jurisdictions
other than the laws of the United States and the Commonwealth of Massachusetts
and the general corporation laws of the State of Delaware.

      Based upon the foregoing, we are of the opinion that upon the issuance and
delivery of the Shares, and the receipt of full consideration therefor, in
accordance with the terms of the Registration Statement and the Plan, the Shares
will be legally issued, fully paid and non-assessable shares of the Company's
Common Stock.

      The foregoing assumes that all requisite steps will be taken to comply
with the requirements of the Act and applicable requirements of state laws
regulating the offer and sale of securities.

      We hereby consent to the filing of this opinion as part of the
above-referenced Registration Statement and to the use of our name therein.

                                                Very truly yours,

                                                /s/ Goodwin Procter LLP

                                                GOODWIN PROCTER LLP