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                                                                   Exhibit 10.47


                                    SUBLEASE
                                    --------

CP Clare Corporation, a Massachusetts corporation with a place of business at 78
Cherry Hill Drive, Beverly, Massachusetts ("Sublessor"), and Implant Sciences
Corporation, a Massachusetts corporation with a place of business at 107 Audubon
Road, Wakefield, Massachusetts ("Sublessee"), make this Sublease as of October
1, 1999.

                             PRELIMINARY STATEMENT

Sublessor is the tenant under a Lease dated as of April 1, 1998 as amended by
First Amendment to Lease dated July 10, 1998 (the "Lease"), by and between
Sublessor and TIAA Realty, Inca Delaware Corporation (the "Lessor"), as
landlord, with respect to premises (the "Premises") consisting of approximately
22,878 rentable square feet in the building commonly known as Building 1, 107
Audubon Road, Wakefield, Massachusetts, as more particularly described in the
Lease. A copy of the Lease is attached to this Sublease as Exhibit A.
Capitalized terms used but not defined in this Sublease shall have the meaning
ascribed to such terms in the Lease.

Sublessor wishes to sublet to Sublessee, and Sublessee wishes to accept from
Sublessor, a portion of the Premises consisting of approximately 9,300 rentable
square feet ("Reimbursable Floor Area of the Subleased Premises") shown on the
plan attached to this Lease as Exhibit B (the "Subleased Premises"), on the
terms and conditions set forth in this Sublease.

                                   AGREEMENT

In consideration of the mutual covenants of this Sublease and other valuable
consideration, the receipt and sufficiency of which Sublessee and Sublessor
hereby acknowledge, Sublessor and Sublessee agree as follows:

1.     SUBLEASED PREMISES. Sublessor hereby subleases to Sublessee, and
       Sublessee hereby subleases from Sublessor, the Subleased Premises,
       subject to the terms and conditions of this Sublease. Sublessor shall
       deliver the Subleased Premises to Sublessee on the Subtenant Improvement
       Completion Date (as hereinafter defined) in broom clean condition, free
       of all tenants and occupants other than Sublessee, and with Sublessor's
       Work (as hereinafter defined) complete, but otherwise in such condition
       as exists as of the date of this Sublease.

2.     TERM. The term of this Sublease (the "Sublease Term") shall commence on
       the date (the "Commencement Date") Sublessor delivers the Subleased
       Premises to Sublessee in the condition required in Paragraph 1 of this
       Sublease and shall terminate on March 31, 2003. Subleassee shall have
       access to the Subleased Premises prior to Commencement Date to prepare
       the Subleased Premises for Sublessee's occupancy including, without
       limitation, for the installation of



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       cabling for computers and communication systems, and to move in and
       install sublessee's trade fixtures

3.     MONTHLY BASE RENT. Commencing ninety (90) days after the Commencement
       Date, Sublessee shall pay to Sublessor, without notice or demand, rent at
       an annual rate of $ 67,425.00 ("Base Rent"), subject to increases as
       hereinafter set forth in Exhibit C, in equal monthly installments on the
       first day of each calendar month during the Sublease Term. If the term
       commences or ends on the first day of a month, then the rent for such
       month shall be pro-rated for such fractional period.

4.     OPERATING EXPENSES AND TAXES. Sublessee shall pay to Sublessor,
       Sublessee's respective share of escalation charges in accordance with
       Sections 8.1, 9.1 and 9.2 of the Lease For the purposes of this Sublease,
       Sublessee's proportionate share as of the date of this Sublease is 40.65
       percent of Sublessor's share. Sublessor shall provide Sublessee with all
       calculations of and demands for such additional escalation charges in
       writing.

5.     SECURITY DEPOSIT. Sublessor acknowledges receiving from Sublessee the sum
       of $5,618.00 (the "Security Deposit") as security for the full and timely
       payment and performance of Sublessee's obligations under this Sublease.
       If Sublessee fails to pay or perform in a full and timely manner any of
       its obligations under this sublease, and such failure continues after the
       giving of any required notice and the expiration of any applicable grace
       period, Sublessor may apply all or a portion of the Security Deposit
       toward curing any such failure and compensating Sublessor for any loss,
       damage or expenses arising from such failure. If Sublessor so applies any
       portion of the Security Deposit, Sublessee shall immediately pay to
       Sublessor the amount necessary to restore the Security Deposit to its
       original amount. Sublessor shall deposit the Security Deposit in a
       segregated, interest-bearing money market account identified as holding
       Sublessee's funds and shall pay to Sublessee annually all interest
       accruing on such account. All monies due from Security Deposit at end of
       Sublease shall be returned to Sublessee thirty (30) days after Sublease
       Expiration Date.

6.     SUBORDINATION TO LEASE. This sublease is subject and subordinate to the
       terms and conditions of the Lease. Except as otherwise specified in this
       Sublease, all the terms and conditions of the Lease are incorporated as a
       part of this Sublease, but all references in the Lease to "Landlord",
       "Tenant", "Premises", "Term", "Annual Fixed Rent", or "Fixed Rent",
       "Commencement Date", Reimbursable Floor Area of the Premises",
       "Landlord's Work", and "Tenant Improvement completion Date" shall be
       deemed to refer, respectively, to Sublessor, Sublessee, Subleased
       Premises, Sublease Term, Base Rent, Commencement Date, Reimbursable floor
       Area of the Subleased Premises, Sublessor's Work and Subtenant
       Improvement Completion Date, as such terms may be defined in this
       Sublease.



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7.     SUBLESSOR'S WORK. Before September 30, 1999 (the Subtenant Improvement
       Completion Date"), Sublessor shall complete the following work in a good
       and workmanlike manner and in compliance with all applicable laws: work
       as described in Exhibit D.

8.     DEFAULT BY SUBLESSEE. In the event of a default by Sublessee in the full
       and timely payment and performance of its obligations under the Sublease,
       Sublessor shall have all of the rights and remedies in the Lease with
       respect to defaults by the tenant under the Lease, including without
       limitation the rights and remedies set forth in Article 13 of the Lease.

9.     BROKERS. Sublessor and Sublessee each represent and warrant to the other
       that it has not dealt with any broker other than Greg Klemmer of Klemmer
       Associates, LLC (together, the "Broker") and Avalon Partners, Inc. d/b/a
       CRESA Partners in connection with the consummation of this Sublease.
       Sublessor and Sublessee each shall indemnify and hold harmless the other
       against any loss, damage, claims or liabilities arising out of a failure
       of its representation or the breach of its warranty set forth in the
       previous sentence. Sublessor shall be solely responsible for the payment
       of any brokerage commission due to the Broker.

10.    NOTICES. The second sentence of Section 14.12 of the Lease
       notwithstanding, the addresses of the Sublessor and Sublessee for the
       purposes of this sublease are:


       If to Sublessee:     Implant Sciences Corporation
                            107 Audubon Road Building 1
                            Wakefield, MA 01880-1246

       If to Sublessor:     CP Clare Corporation
                            78 Cherry Hill Drive
                            Beverly, MA 01915-1048

       Either party may change its addresses for notice or demands under this
       Sublease by notice to the other party.

11.    SUBLESSOR'S REPRESENTATION AND WARRANTIES. Sublessor warrants and
       represents that:

       (i)    The copy of the Lease attached to this sublease as Exhibit A is a
              complete and accurate copy of the Lease, which is in effect and
              has not been amended except as set forth in Exhibit A;

       (ii)   To the best of Sublessor's knowledge, Lessor is not in default
              under the Lease, nor has any event occurred which, after any
              applicable notice



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              and/or expiration of any grace period, shall constitute a default
              by Lessor under the Lease;

       (iii)  to the best of Sublessor's knowledge, Sublessor is not in default
              under the Lease, nor has any event occurred which, after any
              applicable notice and/or expiration of any grace period, shall
              constitute a default by Sublessor under the Lease; and

       (iv)   All rent, additional rent and other charges due under the Lease
              have been paid as billed or required in the normal course through
              July 1999.

12.    ENTIRE AGREEMENT. This sublease contains all of the agreements,
       conditions, warranties and representations relating to the sublease of
       the Subleased Premises and may be amended or modified only by written
       instruments executed by both Sublessor and Sublessee.

13.    LESSOR'S CONSENT. This sublease, and the rights and obligations of
       Sublessor and Sublessee under this Sublease, are subject to the condition
       that Lessor consent in writing to this Sublease. If Sublessor and
       Sublessee do not receive such written consent from Lessor on or before
       October 1,, 1999, Sublessor and Sublessee shall each have the right to
       terminate this Sublease by written notice to the other.

14.    ADDITIONAL PROVISIONS.

       (i)    Notwithstanding anything to the contrary herein contained,
              Sublessee shall not be required to pay any charges imposed by the
              Landlord arising out of the failure of the Sublessor to observe
              and comply with any term, provision or obligation of the Lease.

       (ii)   Sublessor agrees to perform all of the obligations of Tenant under
              the Lease so as not to cause a default under the Lease, and
              Sublessor further agrees not to consent to any amendment, revision
              or alteration to the Lease without the prior written consent of
              Sublessee.

       (iii)  Sublessor shall use reasonable efforts to cause Landlord to
              perform any obligations required to be performed by the Landlord
              under the lease. If Landlord shall default in any of its
              obligations to Sublessor, Sublessor shall cooperate with
              Sublessee, upon request by Sublessee, in enforcing Sublessee's
              rights against Landlord under the Lease.

       (iv)   Sublessor will indemnify, save harmless and defend Sublessee from
              and against any loss, liability or damage of any kind arising out
              of or in connection with a breach by Sublessor of the Lease unless
              caused solely by Sublessee's negligence.



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       (v)    If this Sublease is terminated by reason of Sublessor's default
              under the Lease, including failure by Sublessor to pay all rent
              due under the Lease (unless due to Sublessee's acts or failure to
              pay rent to Sublessor), Sublessee shall retain any claim it may
              otherwise have in law or in equity against Sublessor for breach of
              Sublessor's obligations under this Sublease. If Sublessor fails to
              pay rent under the Lease and Sublessee is notified of such failure
              by Landlord, Sublessee may pay rent directly to Landlord,
              including any differential in rent due under this Sublease
              compared to rent due under the Lease, and in such event Sublessor
              shall be liable to Sublessee for such differential plus ten (10%)
              percent interest per annum until paid.

       IN WITNESS WHEREOF, Sublessor and Sublessee execute this sublease as of
       the date first written above.

Sublessor:                              Sublessee:
CP Clare                                Implant Sciences Corporation



                                        /s/ A.J. Armini


By:   /s/ [illegible]                   By:  A.J. Armini
      -------------------------------
Its:  CFO                               Its: President and CEO
      -------------------------------        9-23-99




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                                   EXHIBIT C
                                   ---------

                                RENTAL INCREASES

TERM                                                      RENTAL RATE
----                                                      -----------

October 1, 1999 - December 31, 1999                               $0

January 1, 1999 - March 31, 2000                           $ 7.25 NNN

April 1, 2000 - March 31, 2001                             $ 7.50 NNN

April 1,2001 - March 31, 2002                              $ 7.75 NNN

April 1, 2002 - March 31, 2003                             $ 8.00 NNN



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                                   EXHIBIT D
                                   ---------

                                SUBLESSOR'S WORK

Sublessor is responsible for the following Tenant Improvements:

1.     Demise space and remove walls as per agreed upon plan ( to be initialed
       by both parties and become an addendum to lease);

2.     Construct three openings from Sublessee's existing space into Sublease
       Premises;

3.     Replace ceiling tiles where needed;

4.     Floor tiles and carpet replaced/repaired/installed where needed and
       cleaned throughout;

5.     Replace single and double doors where doorframes currently exist;

6.     Repatch and paint all walls including main office, hallway and cafeteria;

7.     Replace all vinyl base strips;

8.     Remove back room and replace with window and install floor tiles;

9.     Sublessor shall warrant and provide written document from appropriate
       expert that no environmental issues exist with the entire demised
       premises upon occupancy;

10.    All mechanical systems will be in good, working order;

11.    All code requirements are met;