Hi Tancredi and other people involved in neutron counter commissioning, here's a suggestion of what to do during my absence. I expect to be back from my visa interview by Monday 01/26/2004. -Installation of L15_L and L15_R: Per convention, L15_L should be the outer wall (further away from the target) and L15_R the inner wall (closer to the target). Orientation should be such that the fibers are on the side towards the target. The numbering of the bars is still kept from the original left-right-symmetric design (there it was consistently numbered from downstream to upstream), however which may look a little confusing when all of the walls are in the same sector: Schematically: upstream - - - - - - - - - - - - - - - - - - - - - beam line downstream //00 //. //. //13 L15_R //. //. //. //. //. //. L15_L //. //. L20_L L20_R //13 //. ============== ============== //. 00 ........ 13 13 ........ 00 //00 -Cabeling: When gain matching of L15_R is done, swap the cables of this wall to L20_L (the thick wall at backward angle). All left-sector cables are supposed to be connected to L15_L and L15_R. L15_L cable map thus would not change. L15_R will swap the cables with L20_L. Please find a *NEW* map of all future cabling attached (~kohlm/LADS/maps_and_tables/LADS_cables_new.map). There are labels near the end of each bar. These labels start counting from ONE. In the schematics above, the channels are counted from ZERO. We will not change any cabeling at the splitter panels. However, we will swap the L20_L and L15_R input cables to the ADC's and to Miro's modules. To be clear, that is: So far there have been four analog splitter panels (AS) in each sector-crate, numbered from top to bottom as L1-4 and R1-4, respectively. In the VME crate in the left-sector rack, there are 10 of Miro's modules (MM), lets call them MR0-MR4 (=the five on the left half) and ML0-ML4 (=the five on the right half). MR0 and ML0 will be reserved for the Ohio walls. From top to bottom of the analog splitters, the numbering has been SO FAR: ADCchannel: crate.slot.channels, 31=left sector, 30=right sector AS LADS-channels MM ADCribbon ADCchannel L-1 L20_L00-06 ML1 LL1 31.11.00-15 L-2 L20_L07-13 ML2 LL2 31.11.16-31 L-3 L15_L00-06 ML3 LL3 31.11.32-48 L-4 L15_L07-13 ML4 LL4 31.11.48-63 R-1 L20_R00-06 MR1 RL1 30.11.00-15 R-2 L20_R07-13 MR2 RL2 30.11.16-31 R-3 L15_R00-06 MR3 RL3 30.11.32-47 R-4 L15_R07-13 MR4 RL4 30.11.48-63 From top to bottom of the analog splitters, the numbering WILL BE: AS LADS-channels MM ADCribbon ADCchannel L-1 L15_R00-06 MR3 LL1 30.11.32-47 L-2 L15_R07-13 MR4 LL2 30.11.48-63 L-3 L15_L00-06 ML3 LL3 31.11.32-48 L-4 L15_L07-13 ML4 LL4 31.11.48-63 R-1 L20_R00-06 MR1 RL1 30.11.00-15 R-2 L20_R07-13 MR2 RL2 30.11.16-31 R-3 L20_L00-06 ML1 RL3 31.11.00-15 R-4 L20_L07-13 ML2 RL4 31.11.16-31 Thus, the splitter panels in the left-sector rack will contain the L15 walls only, whereas the L20 walls are entirely in the splitter panels of the right-sector rack. Miro's modules will keep inputs of the four walls like before, like the TDCs and ADCs, and the electronics.map thus wouldn't change. Regarding HV cabeling: Either we want to change assignment of detector channels to channels in HV crate in the HVGUI (this has been assumed in the attached map "LADS_cables_new.map") *OR* we want to change the cable connections at the HV crates, i.e. to swap the cables of L20_L and L15_R channel-by-channel. I'd recommend to rather keep the cables where they are and change the HVGUI. The previous "left-sector LADS" would become "L15_L and L15_R", whereas the "right-sector LADS" would become "L20_L and L20_R". Need to notify Adam. -Gain matching with Sr-90: Finish on L15_R before moving cables to L20_L. PROCEDURE: Looking on the scope in Dtunnel at signals of incoming BNC cables in DC 50Ohm coupling mode. Put Sr-90 sources to the center of the scintillator bar (right underneath the coupler of the optical fiber). Trigger on top (bottom) and look at performance of bottom (top) signal. Increase scope trigger threshold until signal does not rise any further and instead begins to change the shape due to increasing fraction of cosmics. In order to have the most reproducible method to determine the pulse height, read the corresponding value from "Measurements - Amplitudes". Match all pulse heights to **55mV**! Though this pulse height is not identical with the pulse height of the beta-endpoint, it is however related to it, and a look into the ADC spectra gave me confidence for a physics threshold of 1.5-2.0 MeVee (4.6-5.5 MeV protons). The endpoint of the Sr-90 beta spectrum was still visible in the ADC spectra, above the hardware threshold. At the same time, the voltages do not need to be raised too much, which should allow for stable operation. In order to take Sr-90 spectra with DAQ: Coda in flashrun, trig lads_singles.settings. I suggest to take a run with the four Sr-90 channels turned on (other channels may be off), after matching the pulse heights. -Timing: There have been installed eight delay cables of 300ft length each, corresponding to delays of ca. 500ns. The cables yet need to be tested and connected between Miro's modules (prompt output CP) and the TDCs. The scalers should now be connected to delayed outputs DCP (just swap from CP). Determine timing offsets of L20_R (backward downstream, which is already cabled up) relative to common strobe = Left ToF 0, channel-by-channel. Use flasher and mask all other ToF channels (trig neutron_timing_calib.settings, Coda configured as physrun).