Exhibit 10.1(b)

                              ACQUIROR SHARES PROXY

                                IRREVOCABLE PROXY

The undersigned hereby irrevocably (to the fullest extent permitted by law)
appoints Michael Cutrer, President and Chief Executive Officer and Alan Edrick,
Vice President and Chief Financial Officer, respectively, of National American
Scientific, Inc., a Delaware corporation ("Acquiror"), and each of them, as the
sole and exclusive attorneys and proxies of the undersigned, with full power of
substitution and resubstitution, to vote and exercise all voting and related
rights (to the full extent that the undersigned is entitled to do so) with
respect to all of the shares of capital stock of Acquiror that are owned of
record by the undersigned as of the date of any meeting of stockholders of
Acquiror called (and at every adjournment or postponement thereof), and as of
the date that any proposed action or approval by written consent of the
stockholders of Acquiror solicited, for the purpose of the election of directors
of Acquiror (collectively, the "Acquiror Shares") in accordance with the terms
of this Irrevocable Proxy. As used herein, the "Merger Agreement" shall mean the
Agreement and Plan of Merger, dated as of October 26, 2003, among Acquiror, AM
Capital I, Inc., a Delaware corporation and wholly-owned subsidiary of Acquiror
("Merger Sub"), and NOMOS Corporation, a Delaware corporation ("Company"), which
provides for the merger (the "Merger") of Company with and into Merger Sub and
the other transactions contemplated by the Merger Agreement. Upon the
undersigned's execution of this Irrevocable Proxy, any and all prior proxies
provided by the undersigned with respect to any Acquiror Shares are hereby
revoked and the undersigned agrees not to grant any subsequent proxies with
respect to the Acquiror Shares until after the Expiration Date (as such term is
hereinafter defined).

This Irrevocable Proxy is irrevocable (to the fullest extent permitted by
applicable law), is coupled with an interest and is granted pursuant to the
Voting Agreement of even date herewith between Acquiror and the undersigned (the
"Voting Agreement") and is granted in consideration of Acquiror entering into
the Merger Agreement. As used herein, the term "Expiration Date" shall mean the
earlier to occur of (i) such date and time as the Merger Agreement shall have
been validly terminated pursuant to Article IX thereof or (ii) the second
anniversary of the date on which the consummation of the Merger (pursuant to the
terms of the Merger Agreement) occurs.

The attorneys and proxies named herein are, and each of them hereby is,
authorized and empowered by the undersigned, at any time prior to the Expiration
Date, to act as the undersigned's attorney and proxy to vote the Acquiror
Shares, and to exercise all voting consent and similar rights of the undersigned
with respect to the Acquiror Shares (including, without limitation, the power to
execute and deliver written consents) at every annual, special or adjourned
meeting of stockholders of Acquiror and in every proposed written consent in
lieu of any such meeting in favor of the election of the individuals nominated
by a majority of the Acquiror Board Designees (as such term is defined herein)
(or the successors thereto) to the board of directors of Acquiror (the "Acquiror
Board") so long as (i) the undersigned or an individual nominated by the
undersigned, provided that the undersigned has timely presented such individual
to the Acquiror Board

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Designees (the "Chairman Nominee"), is among the individuals nominated by a
majority of the Acquiror Board Designees (unless a majority of the Acquiror
Board Designees has reasonably determined that each of the first three
individuals nominated by the undersigned to be the Chairman Nominee for such
election are not qualified or suitable to be a director of the Acquiror) and
(ii) John Manzetti or an individual nominated by the undersigned, provided that
the undersigned has timely presented such individual to the Acquiror Board
Designees (the "Manzetti Nominee"), is among the individuals nominated by a
majority of the Acquiror Board Designees (unless a majority of the Acquiror
Board Designees has reasonably determined that each of the first three
individuals nominated by the undersigned to be the Manzetti Nominee for such
election are not qualified or suitable to be a director of the Acquiror). As
used herein, the "Acquiror Board Designees" shall mean the seven members of the
Acquiror Board (or their successors) after the Effective Time (as such term is
defined herein) that were also members of the Acquiror Board immediately prior
to the Effective Time. As used herein, the "Effective Time" shall mean the
effective time of the Merger which is the time of filing of the Certificate of
Merger for the Merger with the Secretary of State of the State of Delaware in
accordance with the General Corporation Law of the State of Delaware or at such
later time which the parties to the Merger Agreement shall have agreed upon and
designated in the Certificate of Merger for the Merger as the effective time of
the Merger.

The attorneys and proxies named herein may not exercise this Irrevocable Proxy
on any other matter except as provided herein. The undersigned may vote the
Acquiror Shares on all other matters so long as such vote is not inconsistent
with any matters specifically covered by this Irrevocable Proxy.

Any obligation of the undersigned hereunder shall be binding upon the successors
and assigns of the undersigned.

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This Irrevocable Proxy is irrevocable (to the fullest extent permitted by law).
This Irrevocable Proxy shall terminate, and be of no further force and effect,
automatically upon the Expiration Date.

Dated: October 26, 2003


                                        JOHN A. FRIEDE


                                        /s/ John A. Friede
                                        ----------------------------------------
                                        Signature

                                        [IRREVOCABLE PROXY]