Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-40801) (for June 2000) OVERVIEW The YOHKOH Mission is a program of the Japanese Institute of Space and Astronautical Science (ISAS) with collaboration by the U. S. National Aeronautics and Space Administration and the U. K. Science and Engineering Research Council. The YOHKOH satellite was launched on 30 August 1991 from Kagoshima Space Center (KSC) in Japan. The purpose of this mission is to study high energy phenomena in solar flares and the Sun's corona. Under an international cooperative agreement, Lockheed Martin, under NASA contract, is providing a scientific investigation using the Soft X-ray Telescope (SXT), one of the primary experiments of the mission. The SXT was developed at the Lockheed Martin Solar and Astrophysics Laboratory in cooperation with the National Astronomical Observatory of Japan, and the Institute for Astronomy of the University of Tokyo. MAJOR PROGRAMMATIC ACTIVITIES IN THE MONTH SOLAR ACTIVITY In early June, solar activity increased as AR 9026 rotated onto the disk. There were 6 M-class flares; the two strongest ones on 2 and 3 June (both around 19 UT) were well observed by Yohkoh. Solar activity continued to increase as AR 9026 rotated further onto the disk, and as we all know there were three X-class flares. Yohkoh got excellent observations of only one (June 7), but observed the consequences of the June 6 event as a beautiful and curiously robust cusp formed. The cusp was reminiscent of the one studied by Yokoyama et al. The cusp images were picked up by the APOD (Astronomical Picture of the Day) Web site even before we had a chance to write a nugget! The spot group attained an area of 910 millionths. The Yohkoh observations of the first two events (on June 6) were poor, on account of day/night and SAA interference. For the event on the 7th we got good material, but pre-flare observations are skimpy for the same reasons. The flare of the 7th, X1.2, was not obviously eruptive but did have a halo CME - so it must have been - and type II and IV bursts, the latter also suggesting eruption. But the question of how it erupted seems interesting, as described in more detail, below. In mid-June the highlight was an offpoint to observe the Crab Nebula with HXT. SXT emerged from the observation unscathed. We didn't miss any X-class flares during the Crab study, but did manage to miss three M-class flares in the day following due to an error in the SXT table. In late June, solar activity was variable, with the baseline remaining relatively constant but flaring activity ranging from flatline to enthusiastic. NOAA Regions #9046 and #9042 were quite productive. Several of these flares were co-observed by TRACE. CAMPAIGNS The TRACE-La Palma observations continued. We are not officially supporting this campaign, but of course we were all looking mainly at AR 9026. The only official campaign during this period was the HXT observation of the Crab Nebula during the period 14-June-00 10:17 -- 15-June-00 08:44, coordinated by K. Makishima. The spacecraft was offpointed 1.2 degrees from sun center and SXT was turned off during this period. SXT emerged from the offpoint with no problems, and the Crab team is enthusiastically reducing data. Two Science Nuggets have thus far been written on the topic, and we anticipate at least one more when the Crab team manages to create an image (and perhaps one prior to that when we convincingly extract a Crab signal from the noise). SCIENCE SXT observed a fascinating sequence of events during the June 6-7 X-flares. The cusp formed during the events on June 6 wasn't perturbed by the flare and CME of June 7, in spite of the occurrence of a coronal mass ejection, normally thought to imply a large-scale restructuring of the corona. In the SXT images from June 7, The cusp is seen, apparently unchanged in images before and after the flare and CME. The huge flare was a long-decay event, consistent with the coronal mass ejection but somehow (in this case) unrelated to an obvious coronal arcade. Its compact bright structure can be seen better in the EIT movie, which also (incidentally and rather nicely) appears to show a "twanging" effect of the sort previously reported from TRACE observations. This implies the passage of a large-scale wave originating in the flare. Independent of the controversial question (does wave or mass produce a halo CME?) it seems like an easy conclusion that the corona, in this case, exhibited remarkable rigidity. How in the world could the titanic explosion in the low corona not affect the large-scale cusp structure directly above it? If part of the corona erupted, the mechanical support its magnetic field provided to the rest of the corona must have been easily replaced. Yohkoh's hard X-ray telescope observed the Crab Nebula on June 14. In principle, this is an excellent science opportunity, since HXT is the highest-resolution hard X-ray telescope in space until HESSI is launched; HESSI will make its first Crab observation in June 2001 for the same astronomical reason. We're all inspired to do this because of the wonderful Chandra X-ray image of the Crab and its pulsar. In the Chandra soft X-ray image, one can actually see evidence for the rotational motion leading to the accretion disk theorized to be feeding the pulsar, and the jets coming from its poles. Quite amazing. For the first time in its almost nine years of life, Yohkoh has therefore deliberately pointed far, far (1.2 degrees, further than we can see a CME, of course) from Sun center. This took an entire day out of Yohkoh's solar observations, but of course it will be worth it scientifically if the Crab observations succeed. This happened during the "invisible orbits" between 10:18 UT June 14, and 08:45 UT June 15, and Yohkoh has now successfully returned to solar observations. After the observation it will be a long, hard analysis chore, we think, to generate an actual hard X-ray map, so please stay tuned for another Crab nugget in a year or so. We know the total spectrum of the Crab quite well (see Zombeck, for example). The spectrum (nebula plus pulsar, the latter a 10-20% component) very nearly has the convenient form J = 10*E^(-2) ph/cm2-sec-keV which we can use to estimate what HXT will see. In the best energy band for HXT, 23-33 keV, we estimate an efficiency of about 80% over an effective area of 6.25 cm2, do the integral, and find 0.28 counts/sec per subcollimator (HXT has 64). Not bad! The background rate is about 2.5 counts/sec, so the Crab signal is on the order of 10% of the background. This means that we can't easily see the signal directly, but that we can integrate - if we integrate for 20,000 sec, we find a total number of signal counts of 2800 in each subcollimator. The fluctuation in the background should be on the order of sqrt(50000) = 224. Thus S/B is about .11, but S/N after a long integration may be about 12. Pretty good! PUBLICATIONS Submitted: Accepted: Published: PUBLIC USE OF SXT IMAGES We are continuing to make Yohkoh/SXT images available for a variety of uses. Efforts continue to make selected images available on the LMSAL SXT WWW homepage (http://www.lmsal.com/SXT/). We receive requests for the Yohkoh posters (#2 and #3) by way of the form on the SXT homepage. Currently we receive requests via our homepage at the rate of 2 or 3 per day. The WEB access statistics in June were 140772 accesses and 7157 Mbytes transferred for the SXT website and 177648 accesses and 3924 Mbytes transferred for the YPOP website. YOHKOH OPERATIONS AND HEALTH Yohkoh and the SXT continue to function very well. SXT experienced a normal level of Single Event Upset (SEU) events during the month: Bit Map Error 13-Jun-00 Pass 1: 000613-0721 Recovered in the same pass Bit Map Error 23-Jun-00 Pass 1: 000623-0310 Recovered in the same pass Bit Map Error 26-Jun-00 Pass 1: 000626-0307 Recovered in the same pass Page 6 DATA FLOW Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Mar-98 531739 203370 2152348 444637 2596985 974185 27.01 Apr-98 6537 1103 22656 8087 30743 6339 17.09 May-98 7569 1838 28292 19018 47310 9868 17.26 Jun-98 6463 1638 24990 5618 30608 9051 22.82 Jul-98 6810 1892 27046 7357 34403 9970 22.47 Aug-98 5823 1960 22978 14126 37104 11167 23.13 Sep-98 6776 1432 21814 11626 33440 7753 18.82 Oct-98 6573 1901 23520 5198 28718 9220 24.30 Nov-98 6442 1695 25124 26948 52072 9920 16.00 Dec-98 5962 2005 21490 15770 37260 10561 22.08 Jan-99 5494 1825 20087 17620 37707 9622 20.33 Feb-99 5729 1525 30802 9798 40600 10630 20.75 Mar-99 6807 1844 24721 12354 37075 10064 21.35 Apr-99 6715 1371 25113 4179 29292 7791 21.01 May-99 6459 1807 35467 12092 47559 13757 22.44 Jun-99 6217 1915 23542 13051 36593 10086 21.61 Jul-99 5591 1745 20409 25747 46156 9670 17.32 Aug-99 6827 2503 21725 23361 45086 11844 20.80 Sep-99 5768 2011 21890 3434 25324 10846 29.99 Oct-99 5768 2308 22994 10487 33481 11517 25.59 Nov-99 7552 3425 20754 18772 39526 11974 23.25 Dec-99 7488 2791 22047 5354 27401 10663 28.01 Jan-00 5426 1736 19802 4040 23842 8958 27.31 Feb-00 6533 2052 21801 7017 28818 8982 23.76 Mar-00 6447 2007 22692 21914 44606 11192 20.06 Apr-00 6412 2100 31195 7214 38409 13438 25.92 May-00 6995 1556 28175 14961 43136 8967 17.21 Jun-00 5613 1453 19347 14341 33688 7232 17.67 Total 704535 254808 2802821 784121 3586942 1245267 25.77 Number of Full Frame Images Received: 704535 Number of Observing Region Images Received: 3586942 Total: 4291477 Approximate Number of Shutter Moves/CCD Readouts: 7296236 NOTES: * The loss of images is mainly due to BDR overwrites, but there are also occasional DSN dumps which are lost. * It is common to have observing regions which contain more than 64 lines, which requires multiple exposures to make a single observing region image. This is why the number of shutter moves is larger than the number of images received plus those lost. Page 7 ENGINEERING SUMMARY TABLE Month Avg Dark Level # of Dark Spikes CCD Warmings Front Optical (DN) (e/sec) Over 48 Over 64 High / # Support Trans Temp /Days Temp (%) Apr-98 56.44 972.1 214676 23890 20.8 N/A May-98 56.90 989.4 215651 26905 21.4 N/A Jun-98 57.11 997.5 216285 28223 20.1 N/A Jul-98 57.01 993.7 215499 27493 21.4 N/A Aug-98 57.36 1006.7 217355 29544 20.9 N/A Sep-98 57.43 1009.5 218520 29683 20.9 N/A Oct-98 57.59 1015.3 220504 30221 21.3 N/A Nov-98 58.17 1037.0 223755 34614 22.5 / 2 23.4 N/A Dec-98 57.86 1025.5 221918 32420 23.8 N/A Jan-99 58.74 1058.6 227503 38238 23.1 N/A Feb-99 58.44 1047.4 224002 36198 23.2 N/A Mar-99 59.26 1078.1 227900 43051 21.7 N/A Apr-99 58.82 1061.4 225973 38963 23.8 / 1 21.4 N/A May-99 58.68 1056.4 225385 37726 21.6 N/A Jun-99 59.40 1083.0 230091 42440 22.0 N/A Jul-99 59.78 1097.5 231236 46337 23.8 / 1 20.6 N/A Aug-99 59.39 1083.0 229319 43067 21.7 N/A Sep-99 60.04 1107.3 231585 49084 21.8 N/A Oct-99 59.66 1092.9 229735 45263 22.8 N/A Nov-99 59.90 1102.0 231288 47102 23.0 N/A Dec-99 60.55 1126.3 233523 53920 22.5 / 2 25.3 N/A Jan-00 60.27 1115.9 233820 50214 23.4 N/A Feb-00 60.93 1140.6 235079 56836 23.8 N/A Mar-00 60.72 1132.8 234174 54661 22.9 N/A Apr-00 61.10 1147.0 235252 58348 22.2 N/A May-00 61.00 1143.1 234569 57445 21.2 N/A Jun-00 61.09 1146.5 235293 57940 23.2 N/A NOTES: * The dark current calculations are using full half resolution 2.668 sec images not taken in during the SAA. The dark current rate assumes a "fat zero" of 30.5 DN and a gain of 100 e/DN. * The entrance filter failure of 13-Nov-92 eliminated the capability of taking optical images, so the optical transmission is not available after Nov-92. It also caused an increase in the dark current signal, however some of the increase shown here is an increase in the readout noise and is not a function of exposure duration. Page 8 PERSONNEL TRAVEL SXT Foreign Travel between 1-JUN-00 and 30-JUN-00 HANDY 15-JUN-00 30-JUN-00 * 16 (total of 16 days) HUDSON 1-JUN-00 16-JUN-00 16 27-JUN-00 30-JUN-00 * 4 (total of 20 days) NITTA 1-JUN-00 * 09-JUN-00 9 (total of 9 days) ---------------------------------------------------------------- Grand Total of 45 days for 3 people NOTE: The "*" signifies travel that actually ends after 30-JUN-00 SXT Foreign Travel between 1-JUL-00 and 31-JUL-00 HANDY 1-JUL-00 * 20-JUL-00 20 (total of 20 days) HUDSON 1-JUL-00 * 31-JUL-00 * 31 (total of 31 days) ---------------------------------------------------------------- Grand Total of 51 days for 2 people NOTE: The "*" signifies travel that actually ends after 31-JUL-00 Respectfully submitted, Thomas R. Metcalf Frank Friedlaender Page 17 ------------------------------------------------------------------------------- NASA REPORT DOCUMENTATION PAGE (IN LIEU OF NASA FORM 1626) --------------------|--------------------------|------------------------------- 1. REPORT NO. | 2. GOVERNMENT | 3. RECIPIENT'S DR-01 | ACCESSION NO. | CATALOG NO. --------------------|--------------------------|------------------------------- 4. TITLE AND SUBTITLE | 5. REPORT DATE Monthly progress report - for the month of | 10 July 2000 June 2000 |------------------------------- | 6. PERFORMING ORG | CODE: O/L9-41 -----------------------------------------------|------------------------------- 7. AUTHOR(S) | 8. PERFORMING ORGANIZA- T. R. Metcalf | TION REPORT NO: F. M. Friedlaender | |------------------------------- -----------------------------------------------|10. WORK UNIT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS | Lockheed Martin Missiles and Space |------------------------------- Advanced Technology Center, O/L9-41, B/252 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 40801 -----------------------------------------------|------------------------------- 12. SPONSORING AGENCY NAME AND ADDRESS |13. TYPE OF REPORT AND Marshall Space Flight Center (Explorer Program)| PERIOD COVERED Huntsville Alabama 35812 | Progress report for the month Contact: Larry Hill | of June 2000 |------------------------------- |14. SPONSORING AGENCY | CODE MSFC / AP32 -----------------------------------------------|------------------------------- 15. SUPPLEMENTARY NOTES ------------------------------------------------------------------------------- 16. ABSTRACT The SOLAR-A Mission is a program of the Institute of Space and Astronautical Science (ISAS), the Japanese agency for scientific space activity. The SOLAR-A satellite was launched on August 30, 1991, to study high energy phenomena in solar flares. As an international cooperative agreement, Lockheed, under NASA contract, is providing a scientific investigation and has prepared the Soft X-ray Telescope (SXT), one of the two primary experiments of the mission. --------------------------------------|---------------------------------------- 17. KEY WORDS (SUGGESTED BY | 18. DISTRIBUTION STATEMENT AUTHOR(S)) Solar-A, X-ray, CCD, | Space Science, Solar Physics ------------------------|-------------|----------|-----------------|----------- 19. SECURITY CLASSIF. | 20. SECURITY CLASSIF. | 21. NO OF PAGES |22. PRICE (OF THIS REPORT) | (OF THIS PAGE) | | None | None | 8 | ------------------------|------------------------|-----------------|----------- For sale by: Superintendent of Documents, U.S. Government Printing Office From - Wed Jul 19 13:16:14 2000 Received: from hale.IfA.Hawaii.Edu by sag.lmsal.com (8.8.7/1.1.20.3/11Feb00-1226PM) id JAA0000028065; Wed, 12 Jul 2000 09:13:26 -0700 (PDT) Received: from akala.ifa.hawaii.edu (akala.IFA.Hawaii.Edu [128.171.5.14]) by hale.IfA.Hawaii.Edu (8.9.3+Sun/8.9.1) with ESMTP id GAA12877; Wed, 12 Jul 2000 06:13:22 -1000 (HST) Received: from koa-1.ifa.hawaii.edu (koa [199.190.27.229]) by akala.ifa.hawaii.edu (8.9.3+Sun/8.9.1) with ESMTP id GAA23172 for ; Wed, 12 Jul 2000 06:13:21 -1000 (HST) Received: from sag.lmsal.com (sag.lmsal.com [192.68.162.134]) by koa-1.ifa.hawaii.edu (8.9.1b+Sun/8.9.1) with ESMTP id GAA28513 for ; Wed, 12 Jul 2000 06:13:07 -1000 (HST) Received: by sag.lmsal.com (8.8.7/1.1.20.3/11Feb00-1226PM) id JAA0000025867; Wed, 12 Jul 2000 09:11:13 -0700 (PDT) Date: Wed, 12 Jul 2000 09:11:13 -0700 (PDT) From: "James R. Lemen" Message-Id: <200007121611.JAA0000025867@sag.lmsal.com> To: Charles.Holmes@hq.nasa.gov, GABRIEL@iaslab.ias.fr, Keith.Strong@lmco.com, Larry.Hill@msfc.nasa.gov, Michelle.A.Andrews@ccmail.jpl.nasa.gov, Stefan.Waldherr@ccmail.Jpl.Nasa.Gov, Stewart.A.Collins@ccmail.JPL.NASA.Gov, William.Wagner@hq.nasa.gov, acton@physics.montana.edu, alexander@lmsal.com, aschwand@lmsal.com, bruner@lmsal.com, canfield@physics.montana.edu, fisher@ssl.berkeley.edu, fletcher@lmsal.com, freeland@lmsal.com, friedlaender@lmsal.com, hudson@isass0.solar.isas.ac.jp, jimm@sunspot.ssl.berkeley.edu, jlc@mssl.ucl.ac.uk, kharvey@sprchq.com, klimchuk@bandit.nrl.navy.mil, lean@demeter.nrl.navy.mil, leh@wormhole.jpl.nasa.gov, lemen@lmsal.com, linford@lmsal.com, luxel@pacificrim.net, mariska@aspen.nrl.navy.mil, metcalf@lmsal.com, morrison@lmsal.com, nitta@lmsal.com, ogawara@astro.isas.ac.jp, roethig@lmsal.com, sharadk@sunspot.ssl.berkeley.edu, shirts@lmsal.com, slater@lmsal.com, sturrock@flare.stanford.edu, t_forbes@unh.edu, theresa.e.coombs@lmco.com, wuelser@lmsal.com, yohkoh@koa.ifa.hawaii.edu Subject: SXT Monthly for June 2000 Status: U X-Mozilla-Status: 8001 X-Mozilla-Status2: 00000000 X-UIDL: 963938460.435 Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-40801) (for June 2000) OVERVIEW The YOHKOH Mission is a program of the Japanese Institute of Space and Astronautical Science (ISAS) with collaboration by the U. S. National Aeronautics and Space Administration and the U. K. Science and Engineering Research Council. The YOHKOH satellite was launched on 30 August 1991 from Kagoshima Space Center (KSC) in Japan. The purpose of this mission is to study high energy phenomena in solar flares and the Sun's corona. Under an international cooperative agreement, Lockheed Martin, under NASA contract, is providing a scientific investigation using the Soft X-ray Telescope (SXT), one of the primary experiments of the mission. The SXT was developed at the Lockheed Martin Solar and Astrophysics Laboratory in cooperation with the National Astronomical Observatory of Japan, and the Institute for Astronomy of the University of Tokyo. MAJOR PROGRAMMATIC ACTIVITIES IN THE MONTH The activities on the new contract are underway. Many results were presented at the recent SPD meeting, where Principal Investigator Loren Acton received the Hale Prize and gave the Hale lecture. SOLAR ACTIVITY In early June, solar activity increased as AR 9026 rotated onto the disk. There were 6 M-class flares; the two strongest ones on 2 and 3 June (both around 19 UT) were well observed by Yohkoh. Solar activity continued to increase as AR 9026 rotated further onto the disk, and as we all know there were three X-class flares. Yohkoh got excellent observations of only one (June 7), but observed the consequences of the June 6 event as a beautiful and curiously robust cusp formed. The cusp was reminiscent of the one studied by Yokoyama et al. The cusp images were picked up by the APOD (Astronomical Picture of the Day) Web site even before we had a chance to write a nugget! The spot group attained an area of 910 millionths. The Yohkoh observations of the first two events (on June 6) were poor, on account of day/night and SAA interference. For the event on the 7th we got good material, but pre-flare observations are skimpy for the same reasons. The flare of the 7th, X1.2, was not obviously eruptive but did have a halo CME - so it must have been - and type II and IV bursts, the latter also suggesting eruption. But the question of how it erupted seems interesting, as described in more detail, below. In mid-June the highlight was an offpoint to observe the Crab Nebula with HXT. SXT emerged from the observation unscathed. We didn't miss Page 2 any X-class flares during the Crab study, but did manage to miss three M-class flares in the day following due to an error in the SXT table. In late June, solar activity was variable, with the baseline remaining relatively constant but flaring activity ranging from flatline to enthusiastic. NOAA Regions #9046 and #9042 were quite productive. Several of these flares were co-observed by TRACE. CAMPAIGNS The TRACE-La Palma observations continued. We are not officially supporting this campaign, but of course we were all looking mainly at AR 9026. The only official campaign during this period was the HXT observation of the Crab Nebula during the period 14-June-00 10:17 -- 15-June-00 08:44, coordinated by K. Makishima. The spacecraft was offpointed 1.2 degrees from sun center and SXT was turned off during this period. SXT emerged from the offpoint with no problems, and the Crab team is enthusiastically reducing data. Two Science Nuggets have thus far been written on the topic, and we anticipate at least one more when the Crab team manages to create an image (and perhaps one prior to that when we convincingly extract a Crab signal from the noise). SCIENCE SXT observed a fascinating sequence of events during the June 6-7 X-flares. The cusp formed during the events on June 6 wasn't perturbed by the flare and CME of June 7, in spite of the occurrence of a coronal mass ejection, normally thought to imply a large-scale restructuring of the corona. In the SXT images from June 7, The cusp is seen, apparently unchanged in images before and after the flare and CME. The huge flare was a long-decay event, consistent with the coronal mass ejection but somehow (in this case) unrelated to an obvious coronal arcade. Its compact bright structure can be seen better in the EIT movie, which also (incidentally and rather nicely) appears to show a "twanging" effect of the sort previously reported from TRACE observations. This implies the passage of a large-scale wave originating in the flare. Independent of the controversial question (does wave or mass produce a halo CME?) it seems like an easy conclusion that the corona, in this case, exhibited remarkable rigidity. How in the world could the titanic explosion in the low corona not affect the large-scale cusp structure directly above it? If part of the corona erupted, the mechanical support its magnetic field provided to the rest of the corona must have been easily replaced. Yohkoh's hard X-ray telescope observed the Crab Nebula on June 14. In principle, this is an excellent science opportunity, since HXT is the highest-resolution hard X-ray telescope in space until HESSI is launched; HESSI will make its first Crab observation in June 2001 for the same astronomical reason. We're all inspired to do this because of the wonderful Chandra X-ray image of the Crab and its pulsar. In the Chandra soft X-ray image, one can actually see evidence for the Page 3 rotational motion leading to the accretion disk theorized to be feeding the pulsar, and the jets coming from its poles. Quite amazing. For the first time in its almost nine years of life, Yohkoh has therefore deliberately pointed far, far (1.2 degrees, further than we can see a CME, of course) from Sun center. This took an entire day out of Yohkoh's solar observations, but of course it will be worth it scientifically if the Crab observations succeed. This happened during the "invisible orbits" between 10:18 UT June 14, and 08:45 UT June 15, and Yohkoh has now successfully returned to solar observations. After the observation it will be a long, hard analysis chore, we think, to generate an actual hard X-ray map, so please stay tuned for another Crab nugget in a year or so. We know the total spectrum of the Crab quite well (see Zombeck, for example). The spectrum (nebula plus pulsar, the latter a 10-20% component) very nearly has the convenient form J = 10*E^(-2) ph/cm2-sec-keV which we can use to estimate what HXT will see. In the best energy band for HXT, 23-33 keV, we estimate an efficiency of about 80% over an effective area of 6.25 cm2, do the integral, and find 0.28 counts/sec per subcollimator (HXT has 64). Not bad! The background rate is about 2.5 counts/sec, so the Crab signal is on the order of 10% of the background. This means that we can't easily see the signal directly, but that we can integrate - if we integrate for 20,000 sec, we find a total number of signal counts of 2800 in each subcollimator. The fluctuation in the background should be on the order of sqrt(50000) = 224. Thus S/B is about .11, but S/N after a long integration may be about 12. Pretty good! PUBLICATIONS Submitted: Aschwanden,M.J., Fletcher,L., Sakao,T., Kosugi,T., and Hudson,H. 2000, in "Highly Energetic Physical Processes and Mechanisms for Emission from Astrophysical Plasmas", IAU Symposium 195, ASP Conf.Ser. (eds. P.C.H.Martens, S.Tsuruta, and M.A.Weber), 375-376. "Electron Trapping and Precipitation in Asymmetric Solar Flare Loops" URL="ftp://sag.lmsal.com/pub/aschwand/1999_iau195symp.ps" Aschwanden,M.J. 2000, in "Highly Energetic Physical Processes and Mechanisms for Emission from Astrophysical Plasmas", IAU Symposium 195, ASP Conf.Ser. (eds. P.C.H.Martens, S.Tsuruta, and M.A.Weber), 447-448. Summary of Posters on Solar Physics URL="ftp://sag.lmsal.com/pub/aschwand/1999_iau195sum.ps" N. V. Nitta, J. Sato and H. S. Hudson 2000, "Comparison of Soft X-ray and Low-Energy Hard X-ray Images of Solar Flares" Accepted: Published: Page 4 PUBLIC USE OF SXT IMAGES We are continuing to make Yohkoh/SXT images available for a variety of uses. Efforts continue to make selected images available on the LMSAL SXT WWW homepage (http://www.lmsal.com/SXT/). We receive requests for the Yohkoh posters (#2 and #3) by way of the form on the SXT homepage. Currently we receive requests via our homepage at the rate of 2 or 3 per day. The WEB access statistics in June were 147501 accesses and 7972 Mbytes transferred for the SXT website and 179906 accesses and 4099 Mbytes transferred for the YPOP website. YOHKOH OPERATIONS AND HEALTH Yohkoh and the SXT continue to function very well. SXT experienced a normal level of Single Event Upset (SEU) events during the month: Bit Map Error 13-Jun-00 Pass 1: 000613-0721 Recovered in the same pass Bit Map Error 23-Jun-00 Pass 1: 000623-0310 Recovered in the same pass Bit Map Error 26-Jun-00 Pass 1: 000626-0307 Recovered in the same pass Page 5 DATA FLOW Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Mar-98 531739 203370 2152348 444637 2596985 974185 27.01 Apr-98 6537 1103 22656 8087 30743 6339 17.09 May-98 7569 1838 28292 19018 47310 9868 17.26 Jun-98 6463 1638 24990 5618 30608 9051 22.82 Jul-98 6810 1892 27046 7357 34403 9970 22.47 Aug-98 5823 1960 22978 14126 37104 11167 23.13 Sep-98 6776 1432 21814 11626 33440 7753 18.82 Oct-98 6573 1901 23520 5198 28718 9220 24.30 Nov-98 6442 1695 25124 26948 52072 9920 16.00 Dec-98 5962 2005 21490 15770 37260 10561 22.08 Jan-99 5494 1825 20087 17620 37707 9622 20.33 Feb-99 5729 1525 30802 9798 40600 10630 20.75 Mar-99 6807 1844 24721 12354 37075 10064 21.35 Apr-99 6715 1371 25113 4179 29292 7791 21.01 May-99 6459 1807 35467 12092 47559 13757 22.44 Jun-99 6217 1915 23542 13051 36593 10086 21.61 Jul-99 5591 1745 20409 25747 46156 9670 17.32 Aug-99 6827 2503 21725 23361 45086 11844 20.80 Sep-99 5768 2011 21890 3434 25324 10846 29.99 Oct-99 5768 2308 22994 10487 33481 11517 25.59 Nov-99 7552 3425 20754 18772 39526 11974 23.25 Dec-99 7488 2791 22047 5354 27401 10663 28.01 Jan-00 5426 1736 19802 4040 23842 8958 27.31 Feb-00 6533 2052 21801 7017 28818 8982 23.76 Mar-00 6447 2007 22692 21914 44606 11192 20.06 Apr-00 6412 2100 31195 7214 38409 13438 25.92 May-00 6995 1556 28175 14961 43136 8967 17.21 Jun-00 5613 1453 19347 14341 33688 7232 17.67 Total 704535 254808 2802821 784121 3586942 1245267 25.77 Number of Full Frame Images Received: 704535 Number of Observing Region Images Received: 3586942 Total: 4291477 Approximate Number of Shutter Moves/CCD Readouts: 7296236 NOTES: * The loss of images is mainly due to BDR overwrites, but there are also occasional DSN dumps which are lost. * It is common to have observing regions which contain more than 64 lines, which requires multiple exposures to make a single observing region image. This is why the number of shutter moves is larger than the number of images received plus those lost. Page 6 ENGINEERING SUMMARY TABLE Month Avg Dark Level # of Dark Spikes CCD Warmings Front Optical (DN) (e/sec) Over 48 Over 64 High / # Support Trans Temp /Days Temp (%) Apr-98 56.44 972.1 214676 23890 20.8 N/A May-98 56.90 989.4 215651 26905 21.4 N/A Jun-98 57.11 997.5 216285 28223 20.1 N/A Jul-98 57.01 993.7 215499 27493 21.4 N/A Aug-98 57.36 1006.7 217355 29544 20.9 N/A Sep-98 57.43 1009.5 218520 29683 20.9 N/A Oct-98 57.59 1015.3 220504 30221 21.3 N/A Nov-98 58.17 1037.0 223755 34614 22.5 / 2 23.4 N/A Dec-98 57.86 1025.5 221918 32420 23.8 N/A Jan-99 58.74 1058.6 227503 38238 23.1 N/A Feb-99 58.44 1047.4 224002 36198 23.2 N/A Mar-99 59.26 1078.1 227900 43051 21.7 N/A Apr-99 58.82 1061.4 225973 38963 23.8 / 1 21.4 N/A May-99 58.68 1056.4 225385 37726 21.6 N/A Jun-99 59.40 1083.0 230091 42440 22.0 N/A Jul-99 59.78 1097.5 231236 46337 23.8 / 1 20.6 N/A Aug-99 59.39 1083.0 229319 43067 21.7 N/A Sep-99 60.04 1107.3 231585 49084 21.8 N/A Oct-99 59.66 1092.9 229735 45263 22.8 N/A Nov-99 59.90 1102.0 231288 47102 23.0 N/A Dec-99 60.55 1126.3 233523 53920 22.5 / 2 25.3 N/A Jan-00 60.27 1115.9 233820 50214 23.4 N/A Feb-00 60.93 1140.6 235079 56836 23.8 N/A Mar-00 60.72 1132.8 234174 54661 22.9 N/A Apr-00 61.10 1147.0 235252 58348 22.2 N/A May-00 61.00 1143.1 234569 57445 21.2 N/A Jun-00 61.09 1146.5 235293 57940 23.2 N/A NOTES: * The dark current calculations are using full half resolution 2.668 sec images not taken in during the SAA. The dark current rate assumes a "fat zero" of 30.5 DN and a gain of 100 e/DN. * The entrance filter failure of 13-Nov-92 eliminated the capability of taking optical images, so the optical transmission is not available after Nov-92. It also caused an increase in the dark current signal, however some of the increase shown here is an increase in the readout noise and is not a function of exposure duration. Page 7 PERSONNEL TRAVEL SXT Foreign Travel between 1-JUN-00 and 30-JUN-00 HANDY 15-JUN-00 30-JUN-00 * 16 (total of 16 days) HUDSON 1-JUN-00 16-JUN-00 16 27-JUN-00 30-JUN-00 * 4 (total of 20 days) NITTA 1-JUN-00 * 09-JUN-00 9 (total of 9 days) ---------------------------------------------------------------- Grand Total of 45 days for 3 people NOTE: The "*" signifies travel that actually ends after 30-JUN-00 SXT Foreign Travel between 1-JUL-00 and 31-JUL-00 HANDY 1-JUL-00 * 20-JUL-00 20 (total of 20 days) HUDSON 1-JUL-00 * 31-JUL-00 * 31 (total of 31 days) ---------------------------------------------------------------- Grand Total of 51 days for 2 people NOTE: The "*" signifies travel that actually ends after 31-JUL-00 Respectfully submitted, Thomas R. Metcalf Frank Friedlaender Page 8 ------------------------------------------------------------------------------- NASA REPORT DOCUMENTATION PAGE (IN LIEU OF NASA FORM 1626) --------------------|--------------------------|------------------------------- 1. REPORT NO. | 2. GOVERNMENT | 3. RECIPIENT'S DR-01 | ACCESSION NO. | CATALOG NO. --------------------|--------------------------|------------------------------- 4. TITLE AND SUBTITLE | 5. REPORT DATE Monthly progress report - for the month of | 10 July 2000 June 2000 |------------------------------- | 6. PERFORMING ORG | CODE: O/L9-41 -----------------------------------------------|------------------------------- 7. AUTHOR(S) | 8. PERFORMING ORGANIZA- T. R. Metcalf | TION REPORT NO: F. M. Friedlaender | |------------------------------- -----------------------------------------------|10. WORK UNIT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS | Lockheed Martin Missiles and Space |------------------------------- Advanced Technology Center, O/L9-41, B/252 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 00119 -----------------------------------------------|------------------------------- 12. SPONSORING AGENCY NAME AND ADDRESS |13. TYPE OF REPORT AND Marshall Space Flight Center (Explorer Program)| PERIOD COVERED Huntsville Alabama 35812 | Progress report for the month Contact: Larry Hill | of June 2000 |------------------------------- |14. SPONSORING AGENCY | CODE MSFC / AP32 -----------------------------------------------|------------------------------- 15. SUPPLEMENTARY NOTES ------------------------------------------------------------------------------- 16. ABSTRACT The SOLAR-A Mission is a program of the Institute of Space and Astronautical Science (ISAS), the Japanese agency for scientific space activity. The SOLAR-A satellite was launched on August 30, 1991, to study high energy phenomena in solar flares. As an international cooperative agreement, Lockheed, under NASA contract, is providing a scientific investigation and has prepared the Soft X-ray Telescope (SXT), one of the two primary experiments of the mission. --------------------------------------|---------------------------------------- 17. KEY WORDS (SUGGESTED BY | 18. DISTRIBUTION STATEMENT AUTHOR(S)) Solar-A, X-ray, CCD, | Space Science, Solar Physics ------------------------|-------------|----------|-----------------|----------- 19. SECURITY CLASSIF. | 20. SECURITY CLASSIF. | 21. NO OF PAGES |22. PRICE (OF THIS REPORT) | (OF THIS PAGE) | | None | None | 8 | ------------------------|------------------------|-----------------|----------- For sale by: Superintendent of Documents, U.S. Government Printing Office