There is a problem w/ your write-up. Check that you have valied entries for \$CAID and \$Campn in your analysis.php file. If that checks out, then Contact Stansberry"; return ; } // get first matching task $row = mysql_fetch_array($result); $title = $row["title"]; $princ = $row["principal"]; $deputy= $row["deputy"]; $campn0 = $row["campn0"]; $aorkeys = $row["aorkeys"]; // get real name of principal, deputies $princ = ioc_get_person($princ); $princ = $princ[0]; $deps = explode(",",$deputy); foreach ($deps as $depty) { $depty = trim($depty); $depty = ioc_get_person($depty); $depty = $depty[0]; $depty = explode(",",$depty); $depty = $depty[0]; // last names only $deplist[] = $depty; } $deplist = implode(", ", $deplist); $caid = sprintf("%03d",$caid); $file = "mips-".$caid.$campn.".analysis.php"; // if more matches, append the AORKEYS from those $numrows = mysql_num_rows($result); if ($numrows > 1) { $aorkeys = " " . $numrows . " Task Executions:  ". $aorkeys; for ($i=0;$i < mysql_num_rows($result); $i++) { $row = mysql_fetch_array($result); $morekeys = $row["aorkeys"]; $aorkeys = $aorkeys .';  '.$morekeys; } } // END PHP. ?> <? echo "MIPS-$caid, Campaign $campn IOC/SV Analysis"; ?>

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Task Outcome Summary


Abstract

This task was intended to evaluate whether 30 second exposures were the maximum which should be attempted for the 24um array given a nominal cosmic ray flux. Unfortunately, this task executed at the same time as a solar proton event, which raised the CR rate by at least a factor of 10.

Analysis

In MIPS-250, 6 modified AORs were performed with exposure times from 10 to 60 seconds in increments of 10s. The target was simply a dark region near the ecliptic pole with no prominant sources. Data were reduced using the V2.41 DAT and calibration files from Campaign O. The cosmic ray rate per exposure was evaluated by performing IRAF imstat on the pixels with values more than 3 sigma above the photon noise.

Results

Unfortunately for the primary goal of this task, the data were taken during a solar flare. The peak proton flux of this event nicely coincided with the beginning of MIPS-250. The particle flux reached values of 50 PFU for protons with energy > 50 MeV. This is 50 times the rate considered typical for low solar activity. On exposures of 10 s, I measured more than 250 pixels affected by particle hits. On the 30 s exposures, I measured ~800 particle hits. The derived rate is about 25 per sec per sq. cm. This is 10 - 20 times our usual hit rate. Figure 1 shows a 30 s Si:As array image taken during the flare of November 1.

MIPS Si:As array 30 s exposure during 1/11/03 solar flare

Conclusions

MIPS-250 indeed detected many cosmic rays. It was useful in determining the relation between GOES proton counts and CR visible on the 24um array. We conclude that a proton event reaching 50 PFU for protons > 50 MeV corresponds to a count rate of about 25 CR/sec on the Si:As array. However, evaluation of longer 24um exposure times will have to wait for better solar weather.

Output and Deliverable Products

None

Actions Following Analysis

Evaluate need to repeat task during low solar activity.