From tigwiki

This is the same information as is entered in the TIGRESS ELog.

The ADC may show peaks which are abnormally high (spiked peaks) due to that channel's threshold being set too low. Changing the delta threshold may help this by getting rid of unwanted noise.

To change the delta threshold follow these steps:

Note: there are other methods to calculate these values, this is just the simplest one.

• Select the ADC channel number which has spiked.
• Divide by 120
• This will give a number with a remainder.
• Ignore the remainder (even if the number is something like 6.8, ignore the .8)

• At this point:

EITHER: Add 1 to give the slave number

OR: Multiply by 120

Then: Subtract this number from the original ADC channel number to give the channel in the slave which must have its delta threshold changed.

E.g.

ADC Channel: 520

Divide by 120: 4.33

Ignore remainder: 4

Slave number: 5

Slave channel #: 40 [520-(4*120)]

The delta thresholds are changed through the MIDAS Online Database (ODB). If this page is not open click the ODB button on the MIDAS status page. Then select Equipment > Trigger > Settings and then the slave number you have already calculated.

You are then given the option of Ge or BGO type. This is in reference to polarity; Ge = -ve polarity and BGO = +ve polarity. If you do not know the polarity refer to the Current TIGRESS Configuration wiki page.

Once type has been selected you will come to a long page which lists all the channels. Scroll down to the section of the table with "Delta Threshold" written in the left hand column and select the channel you wish to change.

The threshold should be changed such that all spikes on the EHIT are roughly the same size. Alternatively, check the waveform corresponding to the channel in the RAW folder in the Carpere folder system. If there is no or little noise this will be a smooth curve.