@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
        @                                               @
        @    MTA Monitoring Report 3/31/00 - 4/06/00    @
        @                                               @
        @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


             ************ CTI trend *************

No changes are observed. Attached email from Catherine.


     ************** MTA Problem Tracking. *****************

No new problems are reported this week; only same preoblems keep coming:

C28VMONB, CUSOB28V, CIUB5V, CIUB15V, CTUB15V, AWD2TQI, AWD5TQI, SEHSE400, 
2CE01ATM, 2IMINATM, 2IMHVATM, 2CE00ATM, AWD6TQI


                ******** Trending  ***********

In general, no new trends are observed, however, HRMA Struts, 
HSTRTGRD1,2,4, and 5 show strong trend, and may violate the limits
in 2-4  months, if the tends contiune.

Also we are changing a few more mta limits in future (suggested values
below):

Spacecraft Struts: HSSTRTGRD4 		-0.50   1.50    -1.00   2.00
TFTE: 		   HTFTEGRD4 		-0.50   1.00    -1.00   1.20
TFTE: 		   HTFTEGRD5 		-0.50   1.00    -1.00   1.20
TFTE:              HTFTEGRD6 		-1.80   0.50    -2.00   1.00



          *********** ACIS Focal Temperature ********

We had usual peaks around  DOY 91, 93.8, 96.2. The peaks reached  
-106, -110, and -108 C, respectively.

             *************  Telemetry ***********

Nothing special happened. There are usal violations in HRMA, and
many jumps due to possible software bugs.

             *********** Photon Page ************

Mkn observations show good round images; no distotion.


BSID   DETECTOR        GRATING TARGET          ANALYSIS
---------------------------------------------------------
907     ACIS-I          NONE    QB1429-008A,B   OK
857     ACIS-S          NONE    B2 0331+39      OK
944     ACIS-I          NONE    SGR B2          NO DATA POSTED
896     ACIS-I          NONE    ABELL 2219      NO SKY NICE PIC
418     ACIS-S          NONE    MITG J0414+0534 OK
1522    NO INFORMATION                          NO SKY
604     ACIS-S          HETG    ALGOL           NO DATA POSTED
851     AICS-I          NONE    BAL 1044+3656   OK
867     ACIS-S          NONE    Q 1331+170      OK
858     ACIS-S          NONE    B2 0755+37      OK
446     ACIS-I          NONE    MKN 421, ZOFF-2 OK
664     ACIS-I          NONE    1735-269        OK
140     ACIS-S          NONE    E0102-72.3 CHIPS3 OK
440     ACIS-S          NONE    MKN 421, YOFF-15 NO SKY
900     ACIS-I          NONE    MKW 3S          NO SKY
425     ACIS-S          NONE    SBSG 1520+530   NO DATA POSTED
439     ACIS-S          NONE    MKN 421,YOFF-10 OK


        ************ Some Comments from Exparts ********

-----------------------------------------------------------
From Catherine Grant (4/6/00) --- email sent to SOT
-----------------------------------------------------------

Estimating the change in CTI since Jan 29 (when we decreased the
focal plane temperature to -120C) depends strongly on the correlation
you assume between the measured CTI and the cosmic ray background as
measured by the S3 amplitude rejected count rate.  The data used
in this analysis covers the span of Jan. 29 to Apr. 2.

Fitting this correlation in a number of ways to different groupings
of the available CTI data, the worst case CTI change is:
        +1.21 x 10-8 / day

A conservative guestimate of the error is our CTI measurement accuracy
over the measurement span or  2e-6 / 64 = 
         3.12 x 10-8 / day

These numbers can be compared to Dan Schwartz's ACE fluence numbers.