resik weekly

In the display above (click to enlarge), the solar X-ray fluence seen by RESIK (black points) is plotted atop GOES red line. Only periods with good spectral measurements are indicated. The total number of good spectral measurements is given in the title line.

Operation mode:	'3rd order reflections' (ORD3) is used as stand-by mode. 3rd order spectra observations are indicated on the main catalogue page http://www.cbk.pan.wroc.pl/2002.htm (cf. green boxes).
	Starting on Mon, Dec. 23 15:08:24, a modified ORD1 standard has been introduced with Det. B HV = 1419 V. For appropriate ADS settings see the Table below.
Calibrations made:	No calibrations made
ADS Settings:

(ORD1) HV: Det. A - 1450 V, Det. B - 1419 V.				(ORD3) HV: Det. A - 1389 V, Det. B - 1328 V.
Channel		l Band	ADS	Channel		l Band	ADS
#1	#2	3.37 - 3.88 Å	35 - 85	#1	#2	1.16 - 1.29 Å	110 - 230
#2	#0	3.82 - 4.33 Å	80 - 160	#2	#0	1.27 - 1.44 Å	110 - 230
#3	#3	4.31 - 4.89 Å	55 - 110	#3	#3	1.44 - 1.63 Å	110 - 230
#4	#1	4.96 - 6.09 Å	135 - 200	#4	#1	1.65 - 2.03 Å	140 - 230
		software indexes				software indexes
	spectroscopic notation (papers)				spectroscopic notation (papers)

Two HV power supply units (PSU) within RESIK are of basic importance for the instrument operation, as they provide stabilized voltage difference between detector’s corpus and anode. Since detectors operate in the proportional regime, the important aspect of these HV-PSU is the accuracy of the voltage settings and its short- and long-term stability. In Fig. 1, we show the placement of HV-PSU within RESIK spectrometers A and B.

Figure 1. Photographs of the RESIK spectrometers A & B showing the high voltage power supply units. The white thicker wires (red arrows) connect the unit with the detectors’ anodes.

The HV-PSU units have been manufactured at Rutherford-Appleton Laboratory, UK under supervision of dr. Jim Lang. The units are designed according to the same specifications as the BCS Yohkoh (http://ydac.mssl.ucl.ac.uk/guides/index.html).
Each HV-PSU can provide eight levels of HV, stabilized to within ± 1V. The selection of working voltage can be made individually by the command from the on-board computer COMP, for each of the detectors.

Values in red represent the settings used during the detector callibration, and the initial standard values used in first order spectral measurments are given in green. Grey and blue boxes indicate present values used in ORD1 and ORD3 observing modes respectively. Values of anode voltages are controlled in flight (each DGI) and are found to be in agreement (to within 5 V measurement accuracy) with the nominal values.

The report presented has been done in "real time" and so it may contain jargon, blunders, or trivialities. We do not have also an English native speaker in our Wroclaw group! We would be happy to discuss problems mentioned above in more details if necessary.
RESIK data are in the open public domain and can be requested from: http://surfwww.mssl.ucl.ac.uk/surf/data_request.html.

HV Level address	Detector A [V]	Detector B [V]
0	1328	1328
1	1358	1358
2	1389	1389
3	1419	1419
4	1450	1450
5	1480	1480
6	1511	1511
7	1541	1541