Acceptance Criteria for Barrel RPC Modules

The following specifications are the criteria by which we decide whether or not to install a barrel RPC module. This criteria were reviewed and revised at the Barrel KLM meeting held at Princeton on Feb. 1, 1997. All criteria must be rigorously met. In addition, chambers that satisfy the criteria but for once reason or another seem to be marginal can be rejected at the discretion of the test team through the assignment of a "fair" or "poor" overall rating (see last item below).

Barrel RPC Acceptance Criteria

Parameter Value Comments
Gas leak rate <.05 cc/min This is about the limit of our measurement. We may tighten this if an improved method can be devised.
Chamber expansion r>0.6 mm-Aq/cc Use's Gotow-san's definitionm for r
Gas blocks Al We plan to do this anyway.
Efficiency > 85% 1) Single-layer efficiency. 2) Vth=30 mV
Efficiency > 95% 1) Super-layer efficiency. 2) Vth=30 mV
HV plateau > 500 V 1) It should be possible to obtain >85% efficiency over a range of voltages that is at least this wide. 2) Vth=30 mV
X vs Y see note 1) No region away from the center of the chamber having area 30x30 cm**2 or greater should have an efficiency smaller than 75%. Test done for each RPC within the superlayer. 2) This can be done by visual inspection (i.e., test is not meant to be quantitative) of Steve's x vs. y plots. 3) Vth=30mV
Bad strips none "Dead" means not connected or shorted.
Current <1.5 uA/m**2 1) This is current draw from +HV side. If -HV side is used the current in the 1 Gohm resistor should be subtracted. 2) HV = 9KV (total) 3) It is assumed that a training period may be required to attain this value. 4) The current values are averages of about 50 samples.
Max HV +9.5KV A short test should be done to verify that there is no breakdown at this voltage.
Test duration 10 days Chamber should operate in a stable fashion, satisfying the above criteria for this length of time.
Overall - Chambers will be rated as good, fair, or poor, according to how close they are to failing the various cuts listed above. Chambers rated as fair will be installed as a last resort. Chambers rated as poor will not be installed.

Parameter	Value	Comments
Gas leak rate	<.05 cc/min	This is about the limit of our measurement. We may tighten this if an improved method can be devised.
Chamber expansion	r>0.6 mm-Aq/cc	Use's Gotow-san's definitionm for r
Gas blocks	Al	We plan to do this anyway.
Efficiency	> 85%	1) Single-layer efficiency. 2) Vth=30 mV
Efficiency	> 95%	1) Super-layer efficiency. 2) Vth=30 mV
HV plateau	> 500 V	1) It should be possible to obtain >85% efficiency over a range of voltages that is at least this wide. 2) Vth=30 mV
X vs Y	see note	1) No region away from the center of the chamber having area 30x30 cm**2 or greater should have an efficiency smaller than 75%. Test done for each RPC within the superlayer. 2) This can be done by visual inspection (i.e., test is not meant to be quantitative) of Steve's x vs. y plots. 3) Vth=30mV
Bad strips	none	"Dead" means not connected or shorted.
Current	<1.5 uA/m**2	1) This is current draw from +HV side. If -HV side is used the current in the 1 Gohm resistor should be subtracted. 2) HV = 9KV (total) 3) It is assumed that a training period may be required to attain this value. 4) The current values are averages of about 50 samples.
Max HV	+9.5KV	A short test should be done to verify that there is no breakdown at this voltage.
Test duration	10 days	Chamber should operate in a stable fashion, satisfying the above criteria for this length of time.
Overall	-	Chambers will be rated as good, fair, or poor, according to how close they are to failing the various cuts listed above. Chambers rated as fair will be installed as a last resort. Chambers rated as poor will not be installed.