HETG Orientation at XRCF

The diagram below shows the HETG as oriented at XRCF: this is the view from the HRMA towards the HETG where +Z_facility(Up) is at top of page and +Y_facility(South) is to the right. This orientation is rotated 180 degrees about X from the NE80 orientation.

Grating locations are given by a code such as 6EE3 where:

• the leading digit is the shell number (1,3,4,6)
• the next one or two letters specify the sector (designated A,B,...,F,AA,BB,...,FF)
  • sector A is between 9 and 8 o'clock
  • B is between 8 and 7 o'clock,
  • ...
  • F is between 4 and 3 o'clock
  • AA is between 3 and 2 o'clock
  • BB is between 2 and 1 o'clock
  • ...
  • FF is between 10 and 9 o'clock
• the final number gives the grating location within the sector (numbered 1,2,... increasing in CCW direction in this view, i.e., grating 1 is the most clockwise in a given sector.)

When used with the XRCF shutters the following HETG sectors are illuminated:

• Top shutter: BB high-numbered half, CC, DD, EE low-numbered half
• North shutter: EE high-numbered half, FF, A, B low-numbered half
• Bottom shutter: B high-numbered half, C, D, E low-numbered half
• South shutter: E high-numbered half, F, AA, BB low-numbered half