UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                               (Amendment No. 1)*

                                 IONATRON, INC.
--------------------------------------------------------------------------------
                                (Name of Issuer)

                          Common Stock, $.001 par value
                          -----------------------------
                         (Title of Class of Securities)

                                    462070103
                                    ---------
                                 (CUSIP Number)

                                December 31, 2006
                                -----------------
                      (Date of Event which Requires Filing
                               of this Statement)



Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

                  [ ]      Rule 13d-1(b)
                  [X]      Rule 13d-1(c)
                  [ ]      Rule 13d-1(d)



  *The remainder of this cover page shall be filled out for a reporting person's
  initial filing on this form with respect to the subject class of securities,
  and for any subsequent amendment containing information which would alter the
  disclosures provided in a prior cover page.

  The information required on the remainder of this cover page shall not be
  deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
  Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
  the Act but shall be subject to all other provisions of the Act (however, see
  the Notes).

                                  Page 1 of 9






------------------------------                              --------------------
CUSIP No. 462070103                       13G               Page  2 of 9 Pages
------------------------------                              --------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           S.A.C. Capital Advisors, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a) [ ]
                                                                 (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
                       ----- ---------------------------------------------------
                         6  SHARED VOTING POWER
NUMBER OF SHARES
BENEFICIALLY OWNED          6,275,622 (see Item 4)
BY EACH REPORTING     ----- ----------------------------------------------------
PERSON WITH              7  SOLE DISPOSITIVE POWER

                            0
                      ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            6,275,622 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           6,275,622 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]

---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           8.0% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT

                                  Page 2 of 9





------------------------------                              --------------------
CUSIP No. 462070103                       13G               Page  3 of 9 Pages
------------------------------                              --------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           S.A.C. Capital Management, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a) [ ]
                                                                 (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
                       ----- ---------------------------------------------------
                         6  SHARED VOTING POWER
NUMBER OF SHARES
BENEFICIALLY OWNED          6,275,622 (see Item 4)
BY EACH REPORTING     ----- ----------------------------------------------------
PERSON WITH              7  SOLE DISPOSITIVE POWER

                            0
                      ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            6,275,622 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           6,275,622 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]

---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           8.0% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT

                                  Page 3 of 9





------------------------------                              --------------------
CUSIP No. 462070103                       13G               Page  4 of 9 Pages
------------------------------                              --------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           S.A.C. Capital Associates, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a) [ ]
                                                                 (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Anguilla, British West Indies
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
                       ----- ---------------------------------------------------
                         6  SHARED VOTING POWER
NUMBER OF SHARES
BENEFICIALLY OWNED          6,274,122 (see Item 4)
BY EACH REPORTING     ----- ----------------------------------------------------
PERSON WITH              7  SOLE DISPOSITIVE POWER

                            0
                      ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            6,274,122 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           6,274,122 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]

---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           8.0% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT

                                  Page 4 of 9


------------------------------                              --------------------
CUSIP No. 462070103                       13G               Page  5 of 9 Pages
------------------------------                              --------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Steven A. Cohen
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a) [ ]
                                                                 (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           United States
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
                       ----- ---------------------------------------------------
                         6  SHARED VOTING POWER
NUMBER OF SHARES
BENEFICIALLY OWNED          6,275,622 (see Item 4)
BY EACH REPORTING     ----- ----------------------------------------------------
PERSON WITH              7  SOLE DISPOSITIVE POWER

                            0
                      ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            6,275,622 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           6,275,622 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]

---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           8.0% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           IN
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT

                                  Page 5 of 9



Item 1(a)           Name of Issuer:
                    --------------

                    Ionatron, Inc.

Item 1(b)           Address of Issuer's Principal Executive Offices:
                    -----------------------------------------------

                    3716 East Columbia Street, Suite 120
                    Tucson, Arizona 85714

Items 2(a)          Name of Person Filing:
                    ---------------------

                    This statement is filed by: (i) S.A.C. Capital Advisors,
                    LLC, ("SAC Capital Advisors") with respect to shares of
                    common stock, par value $0.001 per share ("Shares"), of the
                    Issuer beneficially owned by S.A.C. Capital Associates, LLC
                    ("SAC Capital Associates") and S.A.C. MultiQuant Fund, LLC
                    ("SAC MultiQuant"); (ii) S.A.C. Capital Management, LLC,
                    ("SAC Capital Management") with respect to Shares
                    beneficially owned by SAC Capital Associates and SAC
                    MultiQuant; (iii) SAC Capital Associates with respect to
                    Shares beneficially owned by it; and (iv) Steven A. Cohen
                    with respect to Shares beneficially owned by SAC Capital
                    Advisors, SAC Capital Management, SAC Capital Associates and
                    SAC MultiQuant.

                    SAC Capital Advisors, SAC Capital Management, SAC Capital
                    Associates and Steven A. Cohen have entered into a Joint
                    Filing Agreement, a copy of which is filed with this
                    Schedule 13G as Exhibit 99.1, pursuant to which they have
                    agreed to file this Schedule 13G jointly in accordance with
                    the provisions of Rule 13d-1(k) of the Securities Exchange
                    Act of 1934, as amended.

Item 2(b)           Address of Principal Business Office:
                    ------------------------------------

                    The address of the principal business office of (i) SAC
                    Capital Advisors and Mr. Cohen is 72 Cummings Point Road,
                    Stamford, Connecticut 06902, (ii) SAC Capital Management is
                    540 Madison Avenue, New York, New York 10022 and (iii) SAC
                    Capital Associates is P.O. Box 58, Victoria House, The
                    Valley, Anguilla, British West Indies.

Item 2(c)           Citizenship:
                    -----------

                    SAC Capital Advisors and SAC Capital Management are Delaware
                    limited liability companies. SAC Capital Associates is an
                    Anguillan limited liability company. Mr. Cohen is a United
                    States citizen.

                                  Page 6 of 9



Item 2(d)           Title of Class of Securities:
                    ----------------------------

                    Common Stock, $0.001 par value per share

Item 2(e)           CUSIP Number:
                    ------------

                    462070103

Item 3              Not Applicable

Item 4              Ownership:
                    ---------

                    The percentages used herein are calculated based upon the
                    Shares issued and outstanding as of February 5, 2007 as
                    reported on the Issuer's prospectus on Form 424B3 filed with
                    the Securities and Exchange Commission on February 6, 2007.

                    As of the close of business on December 31, 2006:

                    1. S.A.C. Capital Advisors, LLC
                    (a)    Amount beneficially owned: 6,275,622
                    (b)    Percent of class: 8.0%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii)   Shared power to vote or direct the vote: 6,275,622
                    (iii)  Sole power to dispose or direct the disposition: -0-
                    (iv)   Shared power to dispose or direct the disposition:
                           6,275,622

                    2. S.A.C. Capital Management, LLC
                    (a)    Amount beneficially owned: 6,275,622
                    (b)    Percent of class: 8.0%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii)   Shared power to vote or direct the vote: 6,275,622
                    (iii)  Sole power to dispose or direct the disposition: -0-
                    (iv)   Shared power to dispose or direct the disposition:
                           6,275,622

                    3. S.A.C. Capital Assoicates, LLC
                    (a)    Amount beneficially owned: 6,274,122
                    (b)    Percent of class: 8.0%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii)   Shared power to vote or direct the vote: 6,274,122
                    (iii)  Sole power to dispose or direct the disposition: -0-
                    (iv)   Shared power to dispose or direct the disposition:
                           6,274,122

                    4. Steven A. Cohen
                    (a)    Amount beneficially owned: 6,275,622
                    (b)    Percent of class: 8.0%
                    (c)(i) Sole power to vote or direct the vote: -0-

                                  Page 7 of 9



                    (ii)   Shared power to vote or direct the vote: 6,275,622
                    (iii)  Sole power to dispose or direct the disposition: -0-
                    (iv)   Shared power to dispose or direct the disposition:
                           6,275,622

                    SAC Capital Advisors, SAC Capital Management and Mr. Cohen
                    own directly no Shares. Pursuant to investment agreements,
                    each of SAC Capital Advisors and SAC Capital Management
                    share all investment and voting power with respect to the
                    securities held by SAC Capital Associates and SAC
                    MultiQuant. Mr. Cohen controls each of SAC Capital Advisors
                    and SAC Capital Management. By reason of the provisions of
                    Rule 13d-3 of the Securities Exchange Act of 1934, as
                    amended, each of SAC Capital Advisors, SAC Capital
                    Management and Mr. Cohen may be deemed to own beneficially
                    6,275,622 Shares (constituting approximately 8.0% of the
                    Shares outstanding). Each of SAC Capital Advisors, SAC
                    Capital Management and Mr. Cohen disclaim beneficial
                    ownership of any of the securities covered by this
                    statement.

Item 5              Ownership of Five Percent or Less of a Class:
                    --------------------------------------------

                    If this statement is being filed to report the fact that as
                    of the date hereof the reporting person has ceased to be the
                    beneficial owner of more than five percent of the class of
                    securities, check the following. [ ]

Item 6              Ownership of More than Five Percent on Behalf of Another
                     -------------------------------------------------------
                    Person:
                    ------

                    Not Applicable

Item 7              Identification and Classification of the
                    ----------------------------------------
                    Subsidiary Which Acquired the Security Being
                    --------------------------------------------
                    Reported on By the Parent Holding Company:
                    -----------------------------------------

                    Not Applicable

Item 8              Identification and Classification of Members
                    --------------------------------------------
                    of the Group:
                    ------------

                    Not Applicable

Item 9              Notice of Dissolution of Group:
                    ------------------------------

                    Not Applicable

                                  Page 8 of 9



Item 10             Certification:
                    -------------

     By signing below the signatory certifies that, to the best of his knowledge
and belief, the securities referred to above were not acquired and are not held
for the purpose of or with the effect of changing or influencing the control of
the issuer of the securities and were not acquired and are not held in
connection with or as a participant in any transaction having that purpose or
effect.

                                    SIGNATURE
                                    ---------

     After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

Dated:  February 14, 2007

S.A.C. CAPITAL ADVISORS, LLC


By: /s/ Peter Nussbaum
    -----------------------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


S.A.C. CAPITAL MANAGEMENT, LLC


By: /s/ Peter Nussbaum
    -----------------------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


S.A.C. CAPITAL ASSOCIATES, LLC


By: /s/ Peter Nussbaum
    -----------------------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


STEVEN A. COHEN


By: /s/ Peter Nussbaum
    -----------------------------------------
Name:   Peter Nussbaum
Title:  Authorized Person

                                  Page 9 of 9